Unneccessary AGG sources removed. Added libpng and zlib sources and static build in cmake.

377 files changed, 108760 insertions, 31984 deletions

diff --git a/xs/CMakeLists.txt b/xs/CMakeLists.txt
index f2c44dde8..73b7cae37 100644
--- a/xs/CMakeLists.txt
+++ b/xs/CMakeLists.txt
@@ -332,18 +332,39 @@ add_library(semver STATIC
     ${LIBDIR}/semver/semver.c
 )
 
+# ##############################################################################
+# Configure rasterizer target
+# ##############################################################################
 
-find_package(PNG REQUIRED)
+option(RASTERIZER_USE_SYSTEM_LIBPNG "Use the libpng present in system instead of
+    the provided copy." OFF)
 
 add_library(rasterizer STATIC
     ${LIBDIR}/libslic3r/Rasterizer/Rasterizer.hpp
     ${LIBDIR}/libslic3r/Rasterizer/Rasterizer.cpp
 )
 
-target_link_libraries(rasterizer ${PNG_LIBRARIES})
-target_include_directories(rasterizer PRIVATE ${PNG_INCLUDE_DIRS})
-target_compile_definitions(rasterizer PRIVATE ${PNG_DEFINITIONS})
-target_link_libraries(libslic3r rasterizer)
+if(RASTERIZER_USE_SYSTEM_LIBPNG)
+    find_package(PNG REQUIRED)
+    target_link_libraries(rasterizer PRIVATE ${PNG_LIBRARIES})
+    target_include_directories(rasterizer PRIVATE ${PNG_INCLUDE_DIRS})
+    target_compile_definitions(rasterizer PRIVATE ${PNG_DEFINITIONS})
+else()
+    add_subdirectory( ${LIBDIR}/png/zlib)
+    add_subdirectory( ${LIBDIR}/png/libpng )
+
+    target_include_directories( png_static PRIVATE
+        ${LIBDIR}/png/zlib
+        ${CMAKE_CURRENT_BINARY_DIR}/src/png/zlib
+        )
+
+    target_link_libraries(rasterizer PRIVATE png_static zlibstatic)
+endif()
+
+target_link_libraries(libslic3r rasterizer )
+
+# ##############################################################################
+
 
 # Generate the Slic3r Perl module (XS) typemap file.
 set(MyTypemap ${CMAKE_CURRENT_BINARY_DIR}/typemap)
diff --git a/xs/src/agg/AUTHORS b/xs/src/agg/AUTHORS
new file mode 100644
index 000000000..2bb6518ec
--- /dev/null
+++ b/xs/src/agg/AUTHORS
@@ -0,0 +1,2 @@
+Anti-Grain Geometry - Version 2.4
+Copyright (C) 2002-2005 Maxim Shemanarev (McSeem) 
diff --git a/xs/src/agg/agg_alpha_mask_u8.h b/xs/src/agg/agg_alpha_mask_u8.h
deleted file mode 100644
index e301c1008..000000000
--- a/xs/src/agg/agg_alpha_mask_u8.h
+++ /dev/null
@@ -1,499 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// scanline_u8 class
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_ALPHA_MASK_U8_INCLUDED
-#define AGG_ALPHA_MASK_U8_INCLUDED
-
-#include <string.h>
-#include "agg_basics.h"
-#include "agg_rendering_buffer.h"
-
-namespace agg
-{
-    //===================================================one_component_mask_u8
-    struct one_component_mask_u8
-    {
-        static unsigned calculate(const int8u* p) { return *p; }
-    };
-    
-
-    //=====================================================rgb_to_gray_mask_u8
-    template<unsigned R, unsigned G, unsigned B>
-    struct rgb_to_gray_mask_u8
-    {
-        static unsigned calculate(const int8u* p) 
-        { 
-            return (p[R]*77 + p[G]*150 + p[B]*29) >> 8; 
-        }
-    };
-
-    //==========================================================alpha_mask_u8
-    template<unsigned Step=1, unsigned Offset=0, class MaskF=one_component_mask_u8>
-    class alpha_mask_u8
-    {
-    public:
-        typedef int8u cover_type;
-        typedef alpha_mask_u8<Step, Offset, MaskF> self_type;
-        enum cover_scale_e
-        { 
-            cover_shift = 8,
-            cover_none  = 0,
-            cover_full  = 255
-        };
-
-        alpha_mask_u8() : m_rbuf(0) {}
-        explicit alpha_mask_u8(rendering_buffer& rbuf) : m_rbuf(&rbuf) {}
-
-        void attach(rendering_buffer& rbuf) { m_rbuf = &rbuf; }
-
-        MaskF& mask_function() { return m_mask_function; }
-        const MaskF& mask_function() const { return m_mask_function; }
-
-        
-        //--------------------------------------------------------------------
-        cover_type pixel(int x, int y) const
-        {
-            if(x >= 0 && y >= 0 && 
-               x < (int)m_rbuf->width() && 
-               y < (int)m_rbuf->height())
-            {
-                return (cover_type)m_mask_function.calculate(
-                                        m_rbuf->row_ptr(y) + x * Step + Offset);
-            }
-            return 0;
-        }
-
-        //--------------------------------------------------------------------
-        cover_type combine_pixel(int x, int y, cover_type val) const
-        {
-            if(x >= 0 && y >= 0 && 
-               x < (int)m_rbuf->width() && 
-               y < (int)m_rbuf->height())
-            {
-                return (cover_type)((cover_full + val * 
-                                     m_mask_function.calculate(
-                                        m_rbuf->row_ptr(y) + x * Step + Offset)) >> 
-                                     cover_shift);
-            }
-            return 0;
-        }
-
-
-        //--------------------------------------------------------------------
-        void fill_hspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            int xmax = m_rbuf->width() - 1;
-            int ymax = m_rbuf->height() - 1;
-
-            int count = num_pix;
-            cover_type* covers = dst;
-
-            if(y < 0 || y > ymax)
-            {
-                memset(dst, 0, num_pix * sizeof(cover_type));
-                return;
-            }
-
-            if(x < 0)
-            {
-                count += x;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers, 0, -x * sizeof(cover_type));
-                covers -= x;
-                x = 0;
-            }
-
-            if(x + count > xmax)
-            {
-                int rest = x + count - xmax - 1;
-                count -= rest;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers + count, 0, rest * sizeof(cover_type));
-            }
-
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *covers++ = (cover_type)m_mask_function.calculate(mask);
-                mask += Step;
-            }
-            while(--count);
-        }
-
-
-        //--------------------------------------------------------------------
-        void combine_hspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            int xmax = m_rbuf->width() - 1;
-            int ymax = m_rbuf->height() - 1;
-
-            int count = num_pix;
-            cover_type* covers = dst;
-
-            if(y < 0 || y > ymax)
-            {
-                memset(dst, 0, num_pix * sizeof(cover_type));
-                return;
-            }
-
-            if(x < 0)
-            {
-                count += x;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers, 0, -x * sizeof(cover_type));
-                covers -= x;
-                x = 0;
-            }
-
-            if(x + count > xmax)
-            {
-                int rest = x + count - xmax - 1;
-                count -= rest;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers + count, 0, rest * sizeof(cover_type));
-            }
-
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *covers = (cover_type)((cover_full + (*covers) * 
-                                       m_mask_function.calculate(mask)) >> 
-                                       cover_shift);
-                ++covers;
-                mask += Step;
-            }
-            while(--count);
-        }
-
-        //--------------------------------------------------------------------
-        void fill_vspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            int xmax = m_rbuf->width() - 1;
-            int ymax = m_rbuf->height() - 1;
-
-            int count = num_pix;
-            cover_type* covers = dst;
-
-            if(x < 0 || x > xmax)
-            {
-                memset(dst, 0, num_pix * sizeof(cover_type));
-                return;
-            }
-
-            if(y < 0)
-            {
-                count += y;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers, 0, -y * sizeof(cover_type));
-                covers -= y;
-                y = 0;
-            }
-
-            if(y + count > ymax)
-            {
-                int rest = y + count - ymax - 1;
-                count -= rest;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers + count, 0, rest * sizeof(cover_type));
-            }
-
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *covers++ = (cover_type)m_mask_function.calculate(mask);
-                mask += m_rbuf->stride();
-            }
-            while(--count);
-        }
-
-        //--------------------------------------------------------------------
-        void combine_vspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            int xmax = m_rbuf->width() - 1;
-            int ymax = m_rbuf->height() - 1;
-
-            int count = num_pix;
-            cover_type* covers = dst;
-
-            if(x < 0 || x > xmax)
-            {
-                memset(dst, 0, num_pix * sizeof(cover_type));
-                return;
-            }
-
-            if(y < 0)
-            {
-                count += y;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers, 0, -y * sizeof(cover_type));
-                covers -= y;
-                y = 0;
-            }
-
-            if(y + count > ymax)
-            {
-                int rest = y + count - ymax - 1;
-                count -= rest;
-                if(count <= 0) 
-                {
-                    memset(dst, 0, num_pix * sizeof(cover_type));
-                    return;
-                }
-                memset(covers + count, 0, rest * sizeof(cover_type));
-            }
-
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *covers = (cover_type)((cover_full + (*covers) * 
-                                       m_mask_function.calculate(mask)) >> 
-                                       cover_shift);
-                ++covers;
-                mask += m_rbuf->stride();
-            }
-            while(--count);
-        }
-
-
-    private:
-        alpha_mask_u8(const self_type&);
-        const self_type& operator = (const self_type&);
-
-        rendering_buffer* m_rbuf;
-        MaskF             m_mask_function;
-    };
-    
-
-    typedef alpha_mask_u8<1, 0> alpha_mask_gray8;   //----alpha_mask_gray8
-
-    typedef alpha_mask_u8<3, 0> alpha_mask_rgb24r;  //----alpha_mask_rgb24r
-    typedef alpha_mask_u8<3, 1> alpha_mask_rgb24g;  //----alpha_mask_rgb24g
-    typedef alpha_mask_u8<3, 2> alpha_mask_rgb24b;  //----alpha_mask_rgb24b
-
-    typedef alpha_mask_u8<3, 2> alpha_mask_bgr24r;  //----alpha_mask_bgr24r
-    typedef alpha_mask_u8<3, 1> alpha_mask_bgr24g;  //----alpha_mask_bgr24g
-    typedef alpha_mask_u8<3, 0> alpha_mask_bgr24b;  //----alpha_mask_bgr24b
-
-    typedef alpha_mask_u8<4, 0> alpha_mask_rgba32r; //----alpha_mask_rgba32r
-    typedef alpha_mask_u8<4, 1> alpha_mask_rgba32g; //----alpha_mask_rgba32g
-    typedef alpha_mask_u8<4, 2> alpha_mask_rgba32b; //----alpha_mask_rgba32b
-    typedef alpha_mask_u8<4, 3> alpha_mask_rgba32a; //----alpha_mask_rgba32a
-
-    typedef alpha_mask_u8<4, 1> alpha_mask_argb32r; //----alpha_mask_argb32r
-    typedef alpha_mask_u8<4, 2> alpha_mask_argb32g; //----alpha_mask_argb32g
-    typedef alpha_mask_u8<4, 3> alpha_mask_argb32b; //----alpha_mask_argb32b
-    typedef alpha_mask_u8<4, 0> alpha_mask_argb32a; //----alpha_mask_argb32a
-
-    typedef alpha_mask_u8<4, 2> alpha_mask_bgra32r; //----alpha_mask_bgra32r
-    typedef alpha_mask_u8<4, 1> alpha_mask_bgra32g; //----alpha_mask_bgra32g
-    typedef alpha_mask_u8<4, 0> alpha_mask_bgra32b; //----alpha_mask_bgra32b
-    typedef alpha_mask_u8<4, 3> alpha_mask_bgra32a; //----alpha_mask_bgra32a
-
-    typedef alpha_mask_u8<4, 3> alpha_mask_abgr32r; //----alpha_mask_abgr32r
-    typedef alpha_mask_u8<4, 2> alpha_mask_abgr32g; //----alpha_mask_abgr32g
-    typedef alpha_mask_u8<4, 1> alpha_mask_abgr32b; //----alpha_mask_abgr32b
-    typedef alpha_mask_u8<4, 0> alpha_mask_abgr32a; //----alpha_mask_abgr32a
-
-    typedef alpha_mask_u8<3, 0, rgb_to_gray_mask_u8<0, 1, 2> > alpha_mask_rgb24gray;  //----alpha_mask_rgb24gray
-    typedef alpha_mask_u8<3, 0, rgb_to_gray_mask_u8<2, 1, 0> > alpha_mask_bgr24gray;  //----alpha_mask_bgr24gray
-    typedef alpha_mask_u8<4, 0, rgb_to_gray_mask_u8<0, 1, 2> > alpha_mask_rgba32gray; //----alpha_mask_rgba32gray
-    typedef alpha_mask_u8<4, 1, rgb_to_gray_mask_u8<0, 1, 2> > alpha_mask_argb32gray; //----alpha_mask_argb32gray
-    typedef alpha_mask_u8<4, 0, rgb_to_gray_mask_u8<2, 1, 0> > alpha_mask_bgra32gray; //----alpha_mask_bgra32gray
-    typedef alpha_mask_u8<4, 1, rgb_to_gray_mask_u8<2, 1, 0> > alpha_mask_abgr32gray; //----alpha_mask_abgr32gray
-
-
-
-    //==========================================================amask_no_clip_u8
-    template<unsigned Step=1, unsigned Offset=0, class MaskF=one_component_mask_u8>
-    class amask_no_clip_u8
-    {
-    public:
-        typedef int8u cover_type;
-        typedef amask_no_clip_u8<Step, Offset, MaskF> self_type;
-        enum cover_scale_e
-        { 
-            cover_shift = 8,
-            cover_none  = 0,
-            cover_full  = 255
-        };
-
-        amask_no_clip_u8() : m_rbuf(0) {}
-        explicit amask_no_clip_u8(rendering_buffer& rbuf) : m_rbuf(&rbuf) {}
-
-        void attach(rendering_buffer& rbuf) { m_rbuf = &rbuf; }
-
-        MaskF& mask_function() { return m_mask_function; }
-        const MaskF& mask_function() const { return m_mask_function; }
-
-
-        //--------------------------------------------------------------------
-        cover_type pixel(int x, int y) const
-        {
-            return (cover_type)m_mask_function.calculate(
-                                   m_rbuf->row_ptr(y) + x * Step + Offset);
-        }
-
-        
-        //--------------------------------------------------------------------
-        cover_type combine_pixel(int x, int y, cover_type val) const
-        {
-            return (cover_type)((cover_full + val * 
-                                 m_mask_function.calculate(
-                                    m_rbuf->row_ptr(y) + x * Step + Offset)) >> 
-                                 cover_shift);
-        }
-
-
-        //--------------------------------------------------------------------
-        void fill_hspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *dst++ = (cover_type)m_mask_function.calculate(mask);
-                mask += Step;
-            }
-            while(--num_pix);
-        }
-
-
-
-        //--------------------------------------------------------------------
-        void combine_hspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *dst = (cover_type)((cover_full + (*dst) * 
-                                    m_mask_function.calculate(mask)) >> 
-                                    cover_shift);
-                ++dst;
-                mask += Step;
-            }
-            while(--num_pix);
-        }
-
-
-        //--------------------------------------------------------------------
-        void fill_vspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *dst++ = (cover_type)m_mask_function.calculate(mask);
-                mask += m_rbuf->stride();
-            }
-            while(--num_pix);
-        }
-
-
-        //--------------------------------------------------------------------
-        void combine_vspan(int x, int y, cover_type* dst, int num_pix) const
-        {
-            const int8u* mask = m_rbuf->row_ptr(y) + x * Step + Offset;
-            do
-            {
-                *dst = (cover_type)((cover_full + (*dst) * 
-                                    m_mask_function.calculate(mask)) >> 
-                                    cover_shift);
-                ++dst;
-                mask += m_rbuf->stride();
-            }
-            while(--num_pix);
-        }
-
-    private:
-        amask_no_clip_u8(const self_type&);
-        const self_type& operator = (const self_type&);
-
-        rendering_buffer* m_rbuf;
-        MaskF             m_mask_function;
-    };
-    
-
-    typedef amask_no_clip_u8<1, 0> amask_no_clip_gray8;   //----amask_no_clip_gray8
-
-    typedef amask_no_clip_u8<3, 0> amask_no_clip_rgb24r;  //----amask_no_clip_rgb24r
-    typedef amask_no_clip_u8<3, 1> amask_no_clip_rgb24g;  //----amask_no_clip_rgb24g
-    typedef amask_no_clip_u8<3, 2> amask_no_clip_rgb24b;  //----amask_no_clip_rgb24b
-
-    typedef amask_no_clip_u8<3, 2> amask_no_clip_bgr24r;  //----amask_no_clip_bgr24r
-    typedef amask_no_clip_u8<3, 1> amask_no_clip_bgr24g;  //----amask_no_clip_bgr24g
-    typedef amask_no_clip_u8<3, 0> amask_no_clip_bgr24b;  //----amask_no_clip_bgr24b
-
-    typedef amask_no_clip_u8<4, 0> amask_no_clip_rgba32r; //----amask_no_clip_rgba32r
-    typedef amask_no_clip_u8<4, 1> amask_no_clip_rgba32g; //----amask_no_clip_rgba32g
-    typedef amask_no_clip_u8<4, 2> amask_no_clip_rgba32b; //----amask_no_clip_rgba32b
-    typedef amask_no_clip_u8<4, 3> amask_no_clip_rgba32a; //----amask_no_clip_rgba32a
-
-    typedef amask_no_clip_u8<4, 1> amask_no_clip_argb32r; //----amask_no_clip_argb32r
-    typedef amask_no_clip_u8<4, 2> amask_no_clip_argb32g; //----amask_no_clip_argb32g
-    typedef amask_no_clip_u8<4, 3> amask_no_clip_argb32b; //----amask_no_clip_argb32b
-    typedef amask_no_clip_u8<4, 0> amask_no_clip_argb32a; //----amask_no_clip_argb32a
-
-    typedef amask_no_clip_u8<4, 2> amask_no_clip_bgra32r; //----amask_no_clip_bgra32r
-    typedef amask_no_clip_u8<4, 1> amask_no_clip_bgra32g; //----amask_no_clip_bgra32g
-    typedef amask_no_clip_u8<4, 0> amask_no_clip_bgra32b; //----amask_no_clip_bgra32b
-    typedef amask_no_clip_u8<4, 3> amask_no_clip_bgra32a; //----amask_no_clip_bgra32a
-
-    typedef amask_no_clip_u8<4, 3> amask_no_clip_abgr32r; //----amask_no_clip_abgr32r
-    typedef amask_no_clip_u8<4, 2> amask_no_clip_abgr32g; //----amask_no_clip_abgr32g
-    typedef amask_no_clip_u8<4, 1> amask_no_clip_abgr32b; //----amask_no_clip_abgr32b
-    typedef amask_no_clip_u8<4, 0> amask_no_clip_abgr32a; //----amask_no_clip_abgr32a
-
-    typedef amask_no_clip_u8<3, 0, rgb_to_gray_mask_u8<0, 1, 2> > amask_no_clip_rgb24gray;  //----amask_no_clip_rgb24gray
-    typedef amask_no_clip_u8<3, 0, rgb_to_gray_mask_u8<2, 1, 0> > amask_no_clip_bgr24gray;  //----amask_no_clip_bgr24gray
-    typedef amask_no_clip_u8<4, 0, rgb_to_gray_mask_u8<0, 1, 2> > amask_no_clip_rgba32gray; //----amask_no_clip_rgba32gray
-    typedef amask_no_clip_u8<4, 1, rgb_to_gray_mask_u8<0, 1, 2> > amask_no_clip_argb32gray; //----amask_no_clip_argb32gray
-    typedef amask_no_clip_u8<4, 0, rgb_to_gray_mask_u8<2, 1, 0> > amask_no_clip_bgra32gray; //----amask_no_clip_bgra32gray
-    typedef amask_no_clip_u8<4, 1, rgb_to_gray_mask_u8<2, 1, 0> > amask_no_clip_abgr32gray; //----amask_no_clip_abgr32gray
-
-
-}
-
-
-
-#endif
diff --git a/xs/src/agg/agg_arc.h b/xs/src/agg/agg_arc.h
deleted file mode 100644
index 17e1d4347..000000000
--- a/xs/src/agg/agg_arc.h
+++ /dev/null
@@ -1,74 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Arc vertex generator
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_ARC_INCLUDED
-#define AGG_ARC_INCLUDED
-
-#include <math.h>
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //=====================================================================arc
-    //
-    // See Implementation agg_arc.cpp 
-    //
-    class arc
-    {
-    public:
-        arc() : m_scale(1.0), m_initialized(false) {}
-        arc(double x,  double y, 
-            double rx, double ry, 
-            double a1, double a2, 
-            bool ccw=true);
-
-        void init(double x,  double y, 
-                  double rx, double ry, 
-                  double a1, double a2, 
-                  bool ccw=true);
-
-        void approximation_scale(double s);
-        double approximation_scale() const { return m_scale;  }
-
-        void rewind(unsigned);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        void normalize(double a1, double a2, bool ccw);
-
-        double   m_x;
-        double   m_y;
-        double   m_rx;
-        double   m_ry;
-        double   m_angle;
-        double   m_start;
-        double   m_end;
-        double   m_scale;
-        double   m_da;
-        bool     m_ccw;
-        bool     m_initialized;
-        unsigned m_path_cmd;
-    };
-
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_arrowhead.h b/xs/src/agg/agg_arrowhead.h
deleted file mode 100644
index 5e029ddee..000000000
--- a/xs/src/agg/agg_arrowhead.h
+++ /dev/null
@@ -1,82 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Simple arrowhead/arrowtail generator 
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_ARROWHEAD_INCLUDED
-#define AGG_ARROWHEAD_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //===============================================================arrowhead
-    //
-    // See implementation agg_arrowhead.cpp 
-    //
-    class arrowhead
-    {
-    public:
-        arrowhead();
-
-        void head(double d1, double d2, double d3, double d4)
-        {
-            m_head_d1 = d1;
-            m_head_d2 = d2;
-            m_head_d3 = d3;
-            m_head_d4 = d4;
-            m_head_flag = true;
-        }
-
-        void head()    { m_head_flag = true; }
-        void no_head() { m_head_flag = false; }
-
-        void tail(double d1, double d2, double d3, double d4)
-        {
-            m_tail_d1 = d1;
-            m_tail_d2 = d2;
-            m_tail_d3 = d3;
-            m_tail_d4 = d4;
-            m_tail_flag = true;
-        }
-
-        void tail()    { m_tail_flag = true;  }
-        void no_tail() { m_tail_flag = false; }
-
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        double   m_head_d1;
-        double   m_head_d2;
-        double   m_head_d3;
-        double   m_head_d4;
-        double   m_tail_d1;
-        double   m_tail_d2;
-        double   m_tail_d3;
-        double   m_tail_d4;
-        bool     m_head_flag;
-        bool     m_tail_flag;
-        double   m_coord[16];
-        unsigned m_cmd[8];
-        unsigned m_curr_id;
-        unsigned m_curr_coord;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_bitset_iterator.h b/xs/src/agg/agg_bitset_iterator.h
deleted file mode 100644
index 7382d5c33..000000000
--- a/xs/src/agg/agg_bitset_iterator.h
+++ /dev/null
@@ -1,54 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_BITSET_ITERATOR_INCLUDED
-#define AGG_BITSET_ITERATOR_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    
-    class bitset_iterator
-    {
-    public:
-        bitset_iterator(const int8u* bits, unsigned offset = 0) :
-            m_bits(bits + (offset >> 3)),
-            m_mask(0x80 >> (offset & 7))
-        {}
-
-        void operator ++ ()
-        {
-            m_mask >>= 1;
-            if(m_mask == 0)
-            {
-                ++m_bits;
-                m_mask = 0x80;
-            }
-        }
-
-        unsigned bit() const
-        {
-            return (*m_bits) & m_mask;
-        }
-
-    private:
-        const int8u* m_bits;
-        int8u        m_mask;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_blur.h b/xs/src/agg/agg_blur.h
deleted file mode 100644
index cd5713f31..000000000
--- a/xs/src/agg/agg_blur.h
+++ /dev/null
@@ -1,1503 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// The Stack Blur Algorithm was invented by Mario Klingemann, 
-// mario@quasimondo.com and described here:
-// http://incubator.quasimondo.com/processing/fast_blur_deluxe.php
-// (search phrase "Stackblur: Fast But Goodlooking"). 
-// The major improvement is that there's no more division table
-// that was very expensive to create for large blur radii. Insted, 
-// for 8-bit per channel and radius not exceeding 254 the division is 
-// replaced by multiplication and shift. 
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_BLUR_INCLUDED
-#define AGG_BLUR_INCLUDED
-
-#include "agg_array.h"
-#include "agg_pixfmt_base.h"
-#include "agg_pixfmt_transposer.h"
-
-namespace agg
-{
-
-    template<class T> struct stack_blur_tables
-    {
-        static int16u const g_stack_blur8_mul[255];
-        static int8u  const g_stack_blur8_shr[255];
-    };
-
-    //------------------------------------------------------------------------
-    template<class T> 
-    int16u const stack_blur_tables<T>::g_stack_blur8_mul[255] = 
-    {
-        512,512,456,512,328,456,335,512,405,328,271,456,388,335,292,512,
-        454,405,364,328,298,271,496,456,420,388,360,335,312,292,273,512,
-        482,454,428,405,383,364,345,328,312,298,284,271,259,496,475,456,
-        437,420,404,388,374,360,347,335,323,312,302,292,282,273,265,512,
-        497,482,468,454,441,428,417,405,394,383,373,364,354,345,337,328,
-        320,312,305,298,291,284,278,271,265,259,507,496,485,475,465,456,
-        446,437,428,420,412,404,396,388,381,374,367,360,354,347,341,335,
-        329,323,318,312,307,302,297,292,287,282,278,273,269,265,261,512,
-        505,497,489,482,475,468,461,454,447,441,435,428,422,417,411,405,
-        399,394,389,383,378,373,368,364,359,354,350,345,341,337,332,328,
-        324,320,316,312,309,305,301,298,294,291,287,284,281,278,274,271,
-        268,265,262,259,257,507,501,496,491,485,480,475,470,465,460,456,
-        451,446,442,437,433,428,424,420,416,412,408,404,400,396,392,388,
-        385,381,377,374,370,367,363,360,357,354,350,347,344,341,338,335,
-        332,329,326,323,320,318,315,312,310,307,304,302,299,297,294,292,
-        289,287,285,282,280,278,275,273,271,269,267,265,263,261,259
-    };
-
-    //------------------------------------------------------------------------
-    template<class T> 
-    int8u const stack_blur_tables<T>::g_stack_blur8_shr[255] = 
-    {
-          9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 
-         17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19, 
-         19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
-         20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
-         21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
-         21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 
-         22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
-         22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 
-         23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
-         23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
-         23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 
-         23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 
-         24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
-         24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
-         24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
-         24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24
-    };
-
-
-
-    //==============================================================stack_blur
-    template<class ColorT, class CalculatorT> class stack_blur
-    {
-    public:
-        typedef ColorT      color_type;
-        typedef CalculatorT calculator_type;
-
-        //--------------------------------------------------------------------
-        template<class Img> void blur_x(Img& img, unsigned radius)
-        {
-            if(radius < 1) return;
-
-            unsigned x, y, xp, i;
-            unsigned stack_ptr;
-            unsigned stack_start;
-
-            color_type      pix;
-            color_type*     stack_pix;
-            calculator_type sum;
-            calculator_type sum_in;
-            calculator_type sum_out;
-
-            unsigned w   = img.width();
-            unsigned h   = img.height();
-            unsigned wm  = w - 1;
-            unsigned div = radius * 2 + 1;
-
-            unsigned div_sum = (radius + 1) * (radius + 1);
-            unsigned mul_sum = 0;
-            unsigned shr_sum = 0;
-            unsigned max_val = color_type::base_mask;
-
-            if(max_val <= 255 && radius < 255)
-            {
-                mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[radius];
-                shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[radius];
-            }
-
-            m_buf.allocate(w, 128);
-            m_stack.allocate(div, 32);
-
-            for(y = 0; y < h; y++)
-            {
-                sum.clear();
-                sum_in.clear();
-                sum_out.clear();
-
-                pix = img.pixel(0, y);
-                for(i = 0; i <= radius; i++)
-                {
-                    m_stack[i] = pix;
-                    sum.add(pix, i + 1);
-                    sum_out.add(pix);
-                }
-                for(i = 1; i <= radius; i++)
-                {
-                    pix = img.pixel((i > wm) ? wm : i, y);
-                    m_stack[i + radius] = pix;
-                    sum.add(pix, radius + 1 - i);
-                    sum_in.add(pix);
-                }
-
-                stack_ptr = radius;
-                for(x = 0; x < w; x++)
-                {
-                    if(mul_sum) sum.calc_pix(m_buf[x], mul_sum, shr_sum);
-                    else        sum.calc_pix(m_buf[x], div_sum);
-
-                    sum.sub(sum_out);
-           
-                    stack_start = stack_ptr + div - radius;
-                    if(stack_start >= div) stack_start -= div;
-                    stack_pix = &m_stack[stack_start];
-
-                    sum_out.sub(*stack_pix);
-
-                    xp = x + radius + 1;
-                    if(xp > wm) xp = wm;
-                    pix = img.pixel(xp, y);
-            
-                    *stack_pix = pix;
-            
-                    sum_in.add(pix);
-                    sum.add(sum_in);
-            
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix = &m_stack[stack_ptr];
-
-                    sum_out.add(*stack_pix);
-                    sum_in.sub(*stack_pix);
-                }
-                img.copy_color_hspan(0, y, w, &m_buf[0]);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        template<class Img> void blur_y(Img& img, unsigned radius)
-        {
-            pixfmt_transposer<Img> img2(img);
-            blur_x(img2, radius);
-        }
-
-        //--------------------------------------------------------------------
-        template<class Img> void blur(Img& img, unsigned radius)
-        {
-            blur_x(img, radius);
-            pixfmt_transposer<Img> img2(img);
-            blur_x(img2, radius);
-        }
-
-    private:
-        pod_vector<color_type> m_buf;
-        pod_vector<color_type> m_stack;
-    };
-
-    //====================================================stack_blur_calc_rgba
-    template<class T=unsigned> struct stack_blur_calc_rgba
-    {
-        typedef T value_type;
-        value_type r,g,b,a;
-
-        AGG_INLINE void clear() 
-        { 
-            r = g = b = a = 0; 
-        }
-
-        template<class ArgT> AGG_INLINE void add(const ArgT& v)
-        {
-            r += v.r;
-            g += v.g;
-            b += v.b;
-            a += v.a;
-        }
-
-        template<class ArgT> AGG_INLINE void add(const ArgT& v, unsigned k)
-        {
-            r += v.r * k;
-            g += v.g * k;
-            b += v.b * k;
-            a += v.a * k;
-        }
-
-        template<class ArgT> AGG_INLINE void sub(const ArgT& v)
-        {
-            r -= v.r;
-            g -= v.g;
-            b -= v.b;
-            a -= v.a;
-        }
-
-        template<class ArgT> AGG_INLINE void calc_pix(ArgT& v, unsigned div)
-        {
-            typedef typename ArgT::value_type value_type;
-            v.r = value_type(r / div);
-            v.g = value_type(g / div);
-            v.b = value_type(b / div);
-            v.a = value_type(a / div);
-        }
-
-        template<class ArgT> 
-        AGG_INLINE void calc_pix(ArgT& v, unsigned mul, unsigned shr)
-        {
-            typedef typename ArgT::value_type value_type;
-            v.r = value_type((r * mul) >> shr);
-            v.g = value_type((g * mul) >> shr);
-            v.b = value_type((b * mul) >> shr);
-            v.a = value_type((a * mul) >> shr);
-        }
-    };
-
-
-    //=====================================================stack_blur_calc_rgb
-    template<class T=unsigned> struct stack_blur_calc_rgb
-    {
-        typedef T value_type;
-        value_type r,g,b;
-
-        AGG_INLINE void clear() 
-        { 
-            r = g = b = 0; 
-        }
-
-        template<class ArgT> AGG_INLINE void add(const ArgT& v)
-        {
-            r += v.r;
-            g += v.g;
-            b += v.b;
-        }
-
-        template<class ArgT> AGG_INLINE void add(const ArgT& v, unsigned k)
-        {
-            r += v.r * k;
-            g += v.g * k;
-            b += v.b * k;
-        }
-
-        template<class ArgT> AGG_INLINE void sub(const ArgT& v)
-        {
-            r -= v.r;
-            g -= v.g;
-            b -= v.b;
-        }
-
-        template<class ArgT> AGG_INLINE void calc_pix(ArgT& v, unsigned div)
-        {
-            typedef typename ArgT::value_type value_type;
-            v.r = value_type(r / div);
-            v.g = value_type(g / div);
-            v.b = value_type(b / div);
-        }
-
-        template<class ArgT> 
-        AGG_INLINE void calc_pix(ArgT& v, unsigned mul, unsigned shr)
-        {
-            typedef typename ArgT::value_type value_type;
-            v.r = value_type((r * mul) >> shr);
-            v.g = value_type((g * mul) >> shr);
-            v.b = value_type((b * mul) >> shr);
-        }
-    };
-
-
-    //====================================================stack_blur_calc_gray
-    template<class T=unsigned> struct stack_blur_calc_gray
-    {
-        typedef T value_type;
-        value_type v;
-
-        AGG_INLINE void clear() 
-        { 
-            v = 0; 
-        }
-
-        template<class ArgT> AGG_INLINE void add(const ArgT& a)
-        {
-            v += a.v;
-        }
-
-        template<class ArgT> AGG_INLINE void add(const ArgT& a, unsigned k)
-        {
-            v += a.v * k;
-        }
-
-        template<class ArgT> AGG_INLINE void sub(const ArgT& a)
-        {
-            v -= a.v;
-        }
-
-        template<class ArgT> AGG_INLINE void calc_pix(ArgT& a, unsigned div)
-        {
-            typedef typename ArgT::value_type value_type;
-            a.v = value_type(v / div);
-        }
-
-        template<class ArgT> 
-        AGG_INLINE void calc_pix(ArgT& a, unsigned mul, unsigned shr)
-        {
-            typedef typename ArgT::value_type value_type;
-            a.v = value_type((v * mul) >> shr);
-        }
-    };
-
-
-
-    //========================================================stack_blur_gray8
-    template<class Img> 
-    void stack_blur_gray8(Img& img, unsigned rx, unsigned ry)
-    {
-        unsigned x, y, xp, yp, i;
-        unsigned stack_ptr;
-        unsigned stack_start;
-
-        const int8u* src_pix_ptr;
-              int8u* dst_pix_ptr;
-        unsigned pix;
-        unsigned stack_pix;
-        unsigned sum;
-        unsigned sum_in;
-        unsigned sum_out;
-
-        unsigned w   = img.width();
-        unsigned h   = img.height();
-        unsigned wm  = w - 1;
-        unsigned hm  = h - 1;
-
-        unsigned div;
-        unsigned mul_sum;
-        unsigned shr_sum;
-
-        pod_vector<int8u> stack;
-
-        if(rx > 0)
-        {
-            if(rx > 254) rx = 254;
-            div = rx * 2 + 1;
-            mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[rx];
-            shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[rx];
-            stack.allocate(div);
-
-            for(y = 0; y < h; y++)
-            {
-                sum = sum_in = sum_out = 0;
-
-                src_pix_ptr = img.pix_ptr(0, y);
-                pix = *src_pix_ptr;
-                for(i = 0; i <= rx; i++)
-                {
-                    stack[i] = pix;
-                    sum     += pix * (i + 1);
-                    sum_out += pix;
-                }
-                for(i = 1; i <= rx; i++)
-                {
-                    if(i <= wm) src_pix_ptr += Img::pix_width; 
-                    pix = *src_pix_ptr; 
-                    stack[i + rx] = pix;
-                    sum    += pix * (rx + 1 - i);
-                    sum_in += pix;
-                }
-
-                stack_ptr = rx;
-                xp = rx;
-                if(xp > wm) xp = wm;
-                src_pix_ptr = img.pix_ptr(xp, y);
-                dst_pix_ptr = img.pix_ptr(0, y);
-                for(x = 0; x < w; x++)
-                {
-                    *dst_pix_ptr = (sum * mul_sum) >> shr_sum;
-                    dst_pix_ptr += Img::pix_width;
-
-                    sum -= sum_out;
-       
-                    stack_start = stack_ptr + div - rx;
-                    if(stack_start >= div) stack_start -= div;
-                    sum_out -= stack[stack_start];
-
-                    if(xp < wm) 
-                    {
-                        src_pix_ptr += Img::pix_width;
-                        pix = *src_pix_ptr;
-                        ++xp;
-                    }
-        
-                    stack[stack_start] = pix;
-        
-                    sum_in += pix;
-                    sum    += sum_in;
-        
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix = stack[stack_ptr];
-
-                    sum_out += stack_pix;
-                    sum_in  -= stack_pix;
-                }
-            }
-        }
-
-        if(ry > 0)
-        {
-            if(ry > 254) ry = 254;
-            div = ry * 2 + 1;
-            mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[ry];
-            shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[ry];
-            stack.allocate(div);
-
-            int stride = img.stride();
-            for(x = 0; x < w; x++)
-            {
-                sum = sum_in = sum_out = 0;
-
-                src_pix_ptr = img.pix_ptr(x, 0);
-                pix = *src_pix_ptr;
-                for(i = 0; i <= ry; i++)
-                {
-                    stack[i] = pix;
-                    sum     += pix * (i + 1);
-                    sum_out += pix;
-                }
-                for(i = 1; i <= ry; i++)
-                {
-                    if(i <= hm) src_pix_ptr += stride; 
-                    pix = *src_pix_ptr; 
-                    stack[i + ry] = pix;
-                    sum    += pix * (ry + 1 - i);
-                    sum_in += pix;
-                }
-
-                stack_ptr = ry;
-                yp = ry;
-                if(yp > hm) yp = hm;
-                src_pix_ptr = img.pix_ptr(x, yp);
-                dst_pix_ptr = img.pix_ptr(x, 0);
-                for(y = 0; y < h; y++)
-                {
-                    *dst_pix_ptr = (sum * mul_sum) >> shr_sum;
-                    dst_pix_ptr += stride;
-
-                    sum -= sum_out;
-       
-                    stack_start = stack_ptr + div - ry;
-                    if(stack_start >= div) stack_start -= div;
-                    sum_out -= stack[stack_start];
-
-                    if(yp < hm) 
-                    {
-                        src_pix_ptr += stride;
-                        pix = *src_pix_ptr;
-                        ++yp;
-                    }
-        
-                    stack[stack_start] = pix;
-        
-                    sum_in += pix;
-                    sum    += sum_in;
-        
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix = stack[stack_ptr];
-
-                    sum_out += stack_pix;
-                    sum_in  -= stack_pix;
-                }
-            }
-        }
-    }
-
-
-
-    //========================================================stack_blur_rgb24
-    template<class Img> 
-    void stack_blur_rgb24(Img& img, unsigned rx, unsigned ry)
-    {
-        typedef typename Img::color_type color_type;
-        typedef typename Img::order_type order_type;
-        enum order_e 
-        { 
-            R = order_type::R, 
-            G = order_type::G, 
-            B = order_type::B 
-        };
-
-        unsigned x, y, xp, yp, i;
-        unsigned stack_ptr;
-        unsigned stack_start;
-
-        const int8u* src_pix_ptr;
-              int8u* dst_pix_ptr;
-        color_type*  stack_pix_ptr;
-
-        unsigned sum_r;
-        unsigned sum_g;
-        unsigned sum_b;
-        unsigned sum_in_r;
-        unsigned sum_in_g;
-        unsigned sum_in_b;
-        unsigned sum_out_r;
-        unsigned sum_out_g;
-        unsigned sum_out_b;
-
-        unsigned w   = img.width();
-        unsigned h   = img.height();
-        unsigned wm  = w - 1;
-        unsigned hm  = h - 1;
-
-        unsigned div;
-        unsigned mul_sum;
-        unsigned shr_sum;
-
-        pod_vector<color_type> stack;
-
-        if(rx > 0)
-        {
-            if(rx > 254) rx = 254;
-            div = rx * 2 + 1;
-            mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[rx];
-            shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[rx];
-            stack.allocate(div);
-
-            for(y = 0; y < h; y++)
-            {
-                sum_r = 
-                sum_g = 
-                sum_b = 
-                sum_in_r = 
-                sum_in_g = 
-                sum_in_b = 
-                sum_out_r = 
-                sum_out_g = 
-                sum_out_b = 0;
-
-                src_pix_ptr = img.pix_ptr(0, y);
-                for(i = 0; i <= rx; i++)
-                {
-                    stack_pix_ptr    = &stack[i];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    sum_r           += src_pix_ptr[R] * (i + 1);
-                    sum_g           += src_pix_ptr[G] * (i + 1);
-                    sum_b           += src_pix_ptr[B] * (i + 1);
-                    sum_out_r       += src_pix_ptr[R];
-                    sum_out_g       += src_pix_ptr[G];
-                    sum_out_b       += src_pix_ptr[B];
-                }
-                for(i = 1; i <= rx; i++)
-                {
-                    if(i <= wm) src_pix_ptr += Img::pix_width; 
-                    stack_pix_ptr = &stack[i + rx];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    sum_r           += src_pix_ptr[R] * (rx + 1 - i);
-                    sum_g           += src_pix_ptr[G] * (rx + 1 - i);
-                    sum_b           += src_pix_ptr[B] * (rx + 1 - i);
-                    sum_in_r        += src_pix_ptr[R];
-                    sum_in_g        += src_pix_ptr[G];
-                    sum_in_b        += src_pix_ptr[B];
-                }
-
-                stack_ptr = rx;
-                xp = rx;
-                if(xp > wm) xp = wm;
-                src_pix_ptr = img.pix_ptr(xp, y);
-                dst_pix_ptr = img.pix_ptr(0, y);
-                for(x = 0; x < w; x++)
-                {
-                    dst_pix_ptr[R] = (sum_r * mul_sum) >> shr_sum;
-                    dst_pix_ptr[G] = (sum_g * mul_sum) >> shr_sum;
-                    dst_pix_ptr[B] = (sum_b * mul_sum) >> shr_sum;
-                    dst_pix_ptr   += Img::pix_width;
-
-                    sum_r -= sum_out_r;
-                    sum_g -= sum_out_g;
-                    sum_b -= sum_out_b;
-       
-                    stack_start = stack_ptr + div - rx;
-                    if(stack_start >= div) stack_start -= div;
-                    stack_pix_ptr = &stack[stack_start];
-
-                    sum_out_r -= stack_pix_ptr->r;
-                    sum_out_g -= stack_pix_ptr->g;
-                    sum_out_b -= stack_pix_ptr->b;
-
-                    if(xp < wm) 
-                    {
-                        src_pix_ptr += Img::pix_width;
-                        ++xp;
-                    }
-        
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-        
-                    sum_in_r += src_pix_ptr[R];
-                    sum_in_g += src_pix_ptr[G];
-                    sum_in_b += src_pix_ptr[B];
-                    sum_r    += sum_in_r;
-                    sum_g    += sum_in_g;
-                    sum_b    += sum_in_b;
-        
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix_ptr = &stack[stack_ptr];
-
-                    sum_out_r += stack_pix_ptr->r;
-                    sum_out_g += stack_pix_ptr->g;
-                    sum_out_b += stack_pix_ptr->b;
-                    sum_in_r  -= stack_pix_ptr->r;
-                    sum_in_g  -= stack_pix_ptr->g;
-                    sum_in_b  -= stack_pix_ptr->b;
-                }
-            }
-        }
-
-        if(ry > 0)
-        {
-            if(ry > 254) ry = 254;
-            div = ry * 2 + 1;
-            mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[ry];
-            shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[ry];
-            stack.allocate(div);
-
-            int stride = img.stride();
-            for(x = 0; x < w; x++)
-            {
-                sum_r = 
-                sum_g = 
-                sum_b = 
-                sum_in_r = 
-                sum_in_g = 
-                sum_in_b = 
-                sum_out_r = 
-                sum_out_g = 
-                sum_out_b = 0;
-
-                src_pix_ptr = img.pix_ptr(x, 0);
-                for(i = 0; i <= ry; i++)
-                {
-                    stack_pix_ptr    = &stack[i];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    sum_r           += src_pix_ptr[R] * (i + 1);
-                    sum_g           += src_pix_ptr[G] * (i + 1);
-                    sum_b           += src_pix_ptr[B] * (i + 1);
-                    sum_out_r       += src_pix_ptr[R];
-                    sum_out_g       += src_pix_ptr[G];
-                    sum_out_b       += src_pix_ptr[B];
-                }
-                for(i = 1; i <= ry; i++)
-                {
-                    if(i <= hm) src_pix_ptr += stride; 
-                    stack_pix_ptr = &stack[i + ry];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    sum_r           += src_pix_ptr[R] * (ry + 1 - i);
-                    sum_g           += src_pix_ptr[G] * (ry + 1 - i);
-                    sum_b           += src_pix_ptr[B] * (ry + 1 - i);
-                    sum_in_r        += src_pix_ptr[R];
-                    sum_in_g        += src_pix_ptr[G];
-                    sum_in_b        += src_pix_ptr[B];
-                }
-
-                stack_ptr = ry;
-                yp = ry;
-                if(yp > hm) yp = hm;
-                src_pix_ptr = img.pix_ptr(x, yp);
-                dst_pix_ptr = img.pix_ptr(x, 0);
-                for(y = 0; y < h; y++)
-                {
-                    dst_pix_ptr[R] = (sum_r * mul_sum) >> shr_sum;
-                    dst_pix_ptr[G] = (sum_g * mul_sum) >> shr_sum;
-                    dst_pix_ptr[B] = (sum_b * mul_sum) >> shr_sum;
-                    dst_pix_ptr += stride;
-
-                    sum_r -= sum_out_r;
-                    sum_g -= sum_out_g;
-                    sum_b -= sum_out_b;
-       
-                    stack_start = stack_ptr + div - ry;
-                    if(stack_start >= div) stack_start -= div;
-
-                    stack_pix_ptr = &stack[stack_start];
-                    sum_out_r -= stack_pix_ptr->r;
-                    sum_out_g -= stack_pix_ptr->g;
-                    sum_out_b -= stack_pix_ptr->b;
-
-                    if(yp < hm) 
-                    {
-                        src_pix_ptr += stride;
-                        ++yp;
-                    }
-        
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-        
-                    sum_in_r += src_pix_ptr[R];
-                    sum_in_g += src_pix_ptr[G];
-                    sum_in_b += src_pix_ptr[B];
-                    sum_r    += sum_in_r;
-                    sum_g    += sum_in_g;
-                    sum_b    += sum_in_b;
-        
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix_ptr = &stack[stack_ptr];
-
-                    sum_out_r += stack_pix_ptr->r;
-                    sum_out_g += stack_pix_ptr->g;
-                    sum_out_b += stack_pix_ptr->b;
-                    sum_in_r  -= stack_pix_ptr->r;
-                    sum_in_g  -= stack_pix_ptr->g;
-                    sum_in_b  -= stack_pix_ptr->b;
-                }
-            }
-        }
-    }
-
-
-
-    //=======================================================stack_blur_rgba32
-    template<class Img> 
-    void stack_blur_rgba32(Img& img, unsigned rx, unsigned ry)
-    {
-        typedef typename Img::color_type color_type;
-        typedef typename Img::order_type order_type;
-        enum order_e 
-        { 
-            R = order_type::R, 
-            G = order_type::G, 
-            B = order_type::B,
-            A = order_type::A 
-        };
-
-        unsigned x, y, xp, yp, i;
-        unsigned stack_ptr;
-        unsigned stack_start;
-
-        const int8u* src_pix_ptr;
-              int8u* dst_pix_ptr;
-        color_type*  stack_pix_ptr;
-
-        unsigned sum_r;
-        unsigned sum_g;
-        unsigned sum_b;
-        unsigned sum_a;
-        unsigned sum_in_r;
-        unsigned sum_in_g;
-        unsigned sum_in_b;
-        unsigned sum_in_a;
-        unsigned sum_out_r;
-        unsigned sum_out_g;
-        unsigned sum_out_b;
-        unsigned sum_out_a;
-
-        unsigned w   = img.width();
-        unsigned h   = img.height();
-        unsigned wm  = w - 1;
-        unsigned hm  = h - 1;
-
-        unsigned div;
-        unsigned mul_sum;
-        unsigned shr_sum;
-
-        pod_vector<color_type> stack;
-
-        if(rx > 0)
-        {
-            if(rx > 254) rx = 254;
-            div = rx * 2 + 1;
-            mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[rx];
-            shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[rx];
-            stack.allocate(div);
-
-            for(y = 0; y < h; y++)
-            {
-                sum_r = 
-                sum_g = 
-                sum_b = 
-                sum_a = 
-                sum_in_r = 
-                sum_in_g = 
-                sum_in_b = 
-                sum_in_a = 
-                sum_out_r = 
-                sum_out_g = 
-                sum_out_b = 
-                sum_out_a = 0;
-
-                src_pix_ptr = img.pix_ptr(0, y);
-                for(i = 0; i <= rx; i++)
-                {
-                    stack_pix_ptr    = &stack[i];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    stack_pix_ptr->a = src_pix_ptr[A];
-                    sum_r           += src_pix_ptr[R] * (i + 1);
-                    sum_g           += src_pix_ptr[G] * (i + 1);
-                    sum_b           += src_pix_ptr[B] * (i + 1);
-                    sum_a           += src_pix_ptr[A] * (i + 1);
-                    sum_out_r       += src_pix_ptr[R];
-                    sum_out_g       += src_pix_ptr[G];
-                    sum_out_b       += src_pix_ptr[B];
-                    sum_out_a       += src_pix_ptr[A];
-                }
-                for(i = 1; i <= rx; i++)
-                {
-                    if(i <= wm) src_pix_ptr += Img::pix_width; 
-                    stack_pix_ptr = &stack[i + rx];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    stack_pix_ptr->a = src_pix_ptr[A];
-                    sum_r           += src_pix_ptr[R] * (rx + 1 - i);
-                    sum_g           += src_pix_ptr[G] * (rx + 1 - i);
-                    sum_b           += src_pix_ptr[B] * (rx + 1 - i);
-                    sum_a           += src_pix_ptr[A] * (rx + 1 - i);
-                    sum_in_r        += src_pix_ptr[R];
-                    sum_in_g        += src_pix_ptr[G];
-                    sum_in_b        += src_pix_ptr[B];
-                    sum_in_a        += src_pix_ptr[A];
-                }
-
-                stack_ptr = rx;
-                xp = rx;
-                if(xp > wm) xp = wm;
-                src_pix_ptr = img.pix_ptr(xp, y);
-                dst_pix_ptr = img.pix_ptr(0, y);
-                for(x = 0; x < w; x++)
-                {
-                    dst_pix_ptr[R] = (sum_r * mul_sum) >> shr_sum;
-                    dst_pix_ptr[G] = (sum_g * mul_sum) >> shr_sum;
-                    dst_pix_ptr[B] = (sum_b * mul_sum) >> shr_sum;
-                    dst_pix_ptr[A] = (sum_a * mul_sum) >> shr_sum;
-                    dst_pix_ptr += Img::pix_width;
-
-                    sum_r -= sum_out_r;
-                    sum_g -= sum_out_g;
-                    sum_b -= sum_out_b;
-                    sum_a -= sum_out_a;
-       
-                    stack_start = stack_ptr + div - rx;
-                    if(stack_start >= div) stack_start -= div;
-                    stack_pix_ptr = &stack[stack_start];
-
-                    sum_out_r -= stack_pix_ptr->r;
-                    sum_out_g -= stack_pix_ptr->g;
-                    sum_out_b -= stack_pix_ptr->b;
-                    sum_out_a -= stack_pix_ptr->a;
-
-                    if(xp < wm) 
-                    {
-                        src_pix_ptr += Img::pix_width;
-                        ++xp;
-                    }
-        
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    stack_pix_ptr->a = src_pix_ptr[A];
-        
-                    sum_in_r += src_pix_ptr[R];
-                    sum_in_g += src_pix_ptr[G];
-                    sum_in_b += src_pix_ptr[B];
-                    sum_in_a += src_pix_ptr[A];
-                    sum_r    += sum_in_r;
-                    sum_g    += sum_in_g;
-                    sum_b    += sum_in_b;
-                    sum_a    += sum_in_a;
-        
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix_ptr = &stack[stack_ptr];
-
-                    sum_out_r += stack_pix_ptr->r;
-                    sum_out_g += stack_pix_ptr->g;
-                    sum_out_b += stack_pix_ptr->b;
-                    sum_out_a += stack_pix_ptr->a;
-                    sum_in_r  -= stack_pix_ptr->r;
-                    sum_in_g  -= stack_pix_ptr->g;
-                    sum_in_b  -= stack_pix_ptr->b;
-                    sum_in_a  -= stack_pix_ptr->a;
-                }
-            }
-        }
-
-        if(ry > 0)
-        {
-            if(ry > 254) ry = 254;
-            div = ry * 2 + 1;
-            mul_sum = stack_blur_tables<int>::g_stack_blur8_mul[ry];
-            shr_sum = stack_blur_tables<int>::g_stack_blur8_shr[ry];
-            stack.allocate(div);
-
-            int stride = img.stride();
-            for(x = 0; x < w; x++)
-            {
-                sum_r = 
-                sum_g = 
-                sum_b = 
-                sum_a = 
-                sum_in_r = 
-                sum_in_g = 
-                sum_in_b = 
-                sum_in_a = 
-                sum_out_r = 
-                sum_out_g = 
-                sum_out_b = 
-                sum_out_a = 0;
-
-                src_pix_ptr = img.pix_ptr(x, 0);
-                for(i = 0; i <= ry; i++)
-                {
-                    stack_pix_ptr    = &stack[i];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    stack_pix_ptr->a = src_pix_ptr[A];
-                    sum_r           += src_pix_ptr[R] * (i + 1);
-                    sum_g           += src_pix_ptr[G] * (i + 1);
-                    sum_b           += src_pix_ptr[B] * (i + 1);
-                    sum_a           += src_pix_ptr[A] * (i + 1);
-                    sum_out_r       += src_pix_ptr[R];
-                    sum_out_g       += src_pix_ptr[G];
-                    sum_out_b       += src_pix_ptr[B];
-                    sum_out_a       += src_pix_ptr[A];
-                }
-                for(i = 1; i <= ry; i++)
-                {
-                    if(i <= hm) src_pix_ptr += stride; 
-                    stack_pix_ptr = &stack[i + ry];
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    stack_pix_ptr->a = src_pix_ptr[A];
-                    sum_r           += src_pix_ptr[R] * (ry + 1 - i);
-                    sum_g           += src_pix_ptr[G] * (ry + 1 - i);
-                    sum_b           += src_pix_ptr[B] * (ry + 1 - i);
-                    sum_a           += src_pix_ptr[A] * (ry + 1 - i);
-                    sum_in_r        += src_pix_ptr[R];
-                    sum_in_g        += src_pix_ptr[G];
-                    sum_in_b        += src_pix_ptr[B];
-                    sum_in_a        += src_pix_ptr[A];
-                }
-
-                stack_ptr = ry;
-                yp = ry;
-                if(yp > hm) yp = hm;
-                src_pix_ptr = img.pix_ptr(x, yp);
-                dst_pix_ptr = img.pix_ptr(x, 0);
-                for(y = 0; y < h; y++)
-                {
-                    dst_pix_ptr[R] = (sum_r * mul_sum) >> shr_sum;
-                    dst_pix_ptr[G] = (sum_g * mul_sum) >> shr_sum;
-                    dst_pix_ptr[B] = (sum_b * mul_sum) >> shr_sum;
-                    dst_pix_ptr[A] = (sum_a * mul_sum) >> shr_sum;
-                    dst_pix_ptr += stride;
-
-                    sum_r -= sum_out_r;
-                    sum_g -= sum_out_g;
-                    sum_b -= sum_out_b;
-                    sum_a -= sum_out_a;
-       
-                    stack_start = stack_ptr + div - ry;
-                    if(stack_start >= div) stack_start -= div;
-
-                    stack_pix_ptr = &stack[stack_start];
-                    sum_out_r -= stack_pix_ptr->r;
-                    sum_out_g -= stack_pix_ptr->g;
-                    sum_out_b -= stack_pix_ptr->b;
-                    sum_out_a -= stack_pix_ptr->a;
-
-                    if(yp < hm) 
-                    {
-                        src_pix_ptr += stride;
-                        ++yp;
-                    }
-        
-                    stack_pix_ptr->r = src_pix_ptr[R];
-                    stack_pix_ptr->g = src_pix_ptr[G];
-                    stack_pix_ptr->b = src_pix_ptr[B];
-                    stack_pix_ptr->a = src_pix_ptr[A];
-        
-                    sum_in_r += src_pix_ptr[R];
-                    sum_in_g += src_pix_ptr[G];
-                    sum_in_b += src_pix_ptr[B];
-                    sum_in_a += src_pix_ptr[A];
-                    sum_r    += sum_in_r;
-                    sum_g    += sum_in_g;
-                    sum_b    += sum_in_b;
-                    sum_a    += sum_in_a;
-        
-                    ++stack_ptr;
-                    if(stack_ptr >= div) stack_ptr = 0;
-                    stack_pix_ptr = &stack[stack_ptr];
-
-                    sum_out_r += stack_pix_ptr->r;
-                    sum_out_g += stack_pix_ptr->g;
-                    sum_out_b += stack_pix_ptr->b;
-                    sum_out_a += stack_pix_ptr->a;
-                    sum_in_r  -= stack_pix_ptr->r;
-                    sum_in_g  -= stack_pix_ptr->g;
-                    sum_in_b  -= stack_pix_ptr->b;
-                    sum_in_a  -= stack_pix_ptr->a;
-                }
-            }
-        }
-    }
-
-
-
-    //===========================================================recursive_blur
-    template<class ColorT, class CalculatorT> class recursive_blur
-    {
-    public:
-        typedef ColorT color_type;
-        typedef CalculatorT calculator_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename calculator_type::value_type calc_type;
-
-        //--------------------------------------------------------------------
-        template<class Img> void blur_x(Img& img, double radius)
-        {
-            if(radius < 0.62) return;
-            if(img.width() < 3) return;
-
-            calc_type s = calc_type(radius * 0.5);
-            calc_type q = calc_type((s < 2.5) ?
-                                    3.97156 - 4.14554 * sqrt(1 - 0.26891 * s) :
-                                    0.98711 * s - 0.96330);
-
-            calc_type q2 = calc_type(q * q);
-            calc_type q3 = calc_type(q2 * q);
-
-            calc_type b0 = calc_type(1.0 / (1.578250 + 
-                                            2.444130 * q + 
-                                            1.428100 * q2 + 
-                                            0.422205 * q3));
-
-            calc_type b1 = calc_type( 2.44413 * q + 
-                                      2.85619 * q2 + 
-                                      1.26661 * q3);
-
-            calc_type b2 = calc_type(-1.42810 * q2 + 
-                                     -1.26661 * q3);
-
-            calc_type b3 = calc_type(0.422205 * q3);
-
-            calc_type b  = calc_type(1 - (b1 + b2 + b3) * b0);
-
-            b1 *= b0;
-            b2 *= b0;
-            b3 *= b0;
-
-            int w = img.width();
-            int h = img.height();
-            int wm = w-1;
-            int x, y;
-
-            m_sum1.allocate(w);
-            m_sum2.allocate(w);
-            m_buf.allocate(w);
-
-            for(y = 0; y < h; y++)
-            {
-                calculator_type c;
-                c.from_pix(img.pixel(0, y));
-                m_sum1[0].calc(b, b1, b2, b3, c, c, c, c);
-                c.from_pix(img.pixel(1, y));
-                m_sum1[1].calc(b, b1, b2, b3, c, m_sum1[0], m_sum1[0], m_sum1[0]);
-                c.from_pix(img.pixel(2, y));
-                m_sum1[2].calc(b, b1, b2, b3, c, m_sum1[1], m_sum1[0], m_sum1[0]);
-
-                for(x = 3; x < w; ++x)
-                {
-                    c.from_pix(img.pixel(x, y));
-                    m_sum1[x].calc(b, b1, b2, b3, c, m_sum1[x-1], m_sum1[x-2], m_sum1[x-3]);
-                }
-    
-                m_sum2[wm  ].calc(b, b1, b2, b3, m_sum1[wm  ], m_sum1[wm  ], m_sum1[wm], m_sum1[wm]);
-                m_sum2[wm-1].calc(b, b1, b2, b3, m_sum1[wm-1], m_sum2[wm  ], m_sum2[wm], m_sum2[wm]);
-                m_sum2[wm-2].calc(b, b1, b2, b3, m_sum1[wm-2], m_sum2[wm-1], m_sum2[wm], m_sum2[wm]);
-                m_sum2[wm  ].to_pix(m_buf[wm  ]);
-                m_sum2[wm-1].to_pix(m_buf[wm-1]);
-                m_sum2[wm-2].to_pix(m_buf[wm-2]);
-
-                for(x = wm-3; x >= 0; --x)
-                {
-                    m_sum2[x].calc(b, b1, b2, b3, m_sum1[x], m_sum2[x+1], m_sum2[x+2], m_sum2[x+3]);
-                    m_sum2[x].to_pix(m_buf[x]);
-                }
-                img.copy_color_hspan(0, y, w, &m_buf[0]);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        template<class Img> void blur_y(Img& img, double radius)
-        {
-            pixfmt_transposer<Img> img2(img);
-            blur_x(img2, radius);
-        }
-
-        //--------------------------------------------------------------------
-        template<class Img> void blur(Img& img, double radius)
-        {
-            blur_x(img, radius);
-            pixfmt_transposer<Img> img2(img);
-            blur_x(img2, radius);
-        }
-
-    private:
-        agg::pod_vector<calculator_type> m_sum1;
-        agg::pod_vector<calculator_type> m_sum2;
-        agg::pod_vector<color_type>      m_buf;
-    };
-
-
-    //=================================================recursive_blur_calc_rgba
-    template<class T=double> struct recursive_blur_calc_rgba
-    {
-        typedef T value_type;
-        typedef recursive_blur_calc_rgba<T> self_type;
-
-        value_type r,g,b,a;
-
-        template<class ColorT> 
-        AGG_INLINE void from_pix(const ColorT& c)
-        {
-            r = c.r;
-            g = c.g;
-            b = c.b;
-            a = c.a;
-        }
-
-        AGG_INLINE void calc(value_type b1, 
-                             value_type b2, 
-                             value_type b3, 
-                             value_type b4,
-                             const self_type& c1, 
-                             const self_type& c2, 
-                             const self_type& c3, 
-                             const self_type& c4)
-        {
-            r = b1*c1.r + b2*c2.r + b3*c3.r + b4*c4.r;
-            g = b1*c1.g + b2*c2.g + b3*c3.g + b4*c4.g;
-            b = b1*c1.b + b2*c2.b + b3*c3.b + b4*c4.b;
-            a = b1*c1.a + b2*c2.a + b3*c3.a + b4*c4.a;
-        }
-
-        template<class ColorT> 
-        AGG_INLINE void to_pix(ColorT& c) const
-        {
-            typedef typename ColorT::value_type cv_type;
-            c.r = cv_type(r);
-            c.g = cv_type(g);
-            c.b = cv_type(b);
-            c.a = cv_type(a);
-        }
-    };
-
-
-    //=================================================recursive_blur_calc_rgb
-    template<class T=double> struct recursive_blur_calc_rgb
-    {
-        typedef T value_type;
-        typedef recursive_blur_calc_rgb<T> self_type;
-
-        value_type r,g,b;
-
-        template<class ColorT> 
-        AGG_INLINE void from_pix(const ColorT& c)
-        {
-            r = c.r;
-            g = c.g;
-            b = c.b;
-        }
-
-        AGG_INLINE void calc(value_type b1, 
-                             value_type b2, 
-                             value_type b3, 
-                             value_type b4,
-                             const self_type& c1, 
-                             const self_type& c2, 
-                             const self_type& c3, 
-                             const self_type& c4)
-        {
-            r = b1*c1.r + b2*c2.r + b3*c3.r + b4*c4.r;
-            g = b1*c1.g + b2*c2.g + b3*c3.g + b4*c4.g;
-            b = b1*c1.b + b2*c2.b + b3*c3.b + b4*c4.b;
-        }
-
-        template<class ColorT> 
-        AGG_INLINE void to_pix(ColorT& c) const
-        {
-            typedef typename ColorT::value_type cv_type;
-            c.r = cv_type(r);
-            c.g = cv_type(g);
-            c.b = cv_type(b);
-        }
-    };
-
-
-    //================================================recursive_blur_calc_gray
-    template<class T=double> struct recursive_blur_calc_gray
-    {
-        typedef T value_type;
-        typedef recursive_blur_calc_gray<T> self_type;
-
-        value_type v;
-
-        template<class ColorT> 
-        AGG_INLINE void from_pix(const ColorT& c)
-        {
-            v = c.v;
-        }
-
-        AGG_INLINE void calc(value_type b1, 
-                             value_type b2, 
-                             value_type b3, 
-                             value_type b4,
-                             const self_type& c1, 
-                             const self_type& c2, 
-                             const self_type& c3, 
-                             const self_type& c4)
-        {
-            v = b1*c1.v + b2*c2.v + b3*c3.v + b4*c4.v;
-        }
-
-        template<class ColorT> 
-        AGG_INLINE void to_pix(ColorT& c) const
-        {
-            typedef typename ColorT::value_type cv_type;
-            c.v = cv_type(v);
-        }
-    };
-
-    //================================================slight_blur
-    // Special-purpose filter for applying a Gaussian blur with a radius small enough 
-    // that the blur only affects adjacent pixels. A Gaussian curve with a standard
-    // deviation of r/2 is used, as per the HTML/CSS spec. At 3 standard deviations, 
-    // the contribution drops to less than 0.005, i.e. less than half a percent, 
-    // therefore the radius can be at least 1.33 before errors become significant.
-    // This filter is useful for smoothing artifacts caused by detail rendered 
-    // at the pixel scale, e.g. single-pixel lines. Note that the filter should 
-    // only be used with premultiplied pixel formats (or those without alpha).
-    // See the "line_thickness" example for a demonstration.
-    template<class PixFmt>
-    class slight_blur
-    {
-    public:
-        typedef typename PixFmt::pixel_type pixel_type;
-        typedef typename PixFmt::value_type value_type;
-        typedef typename PixFmt::order_type order_type;
-
-        slight_blur(double r = 1.33)
-        {
-            radius(r);
-        }
-
-        void radius(double r)
-        {
-            if (r > 0)
-            {
-                // Sample the gaussian curve at 0 and r/2 standard deviations. 
-                // At 3 standard deviations, the response is < 0.005.
-                double pi = 3.14159;
-                double n = 2 / r;
-                m_g0 = 1 / sqrt(2 * pi);
-                m_g1 = m_g0 * exp(-n * n);
-
-                // Normalize.
-                double sum = m_g0 + 2 * m_g1;
-                m_g0 /= sum;
-                m_g1 /= sum;
-            }
-            else
-            {
-                m_g0 = 1;
-                m_g1 = 0;
-            }
-        }
-
-        void blur(PixFmt& img, rect_i bounds)
-        {
-            // Make sure we stay within the image area.
-            bounds.clip(rect_i(0, 0, img.width() - 1, img.height() - 1));
-
-            int w = bounds.x2 - bounds.x1 + 1;
-            int h = bounds.y2 - bounds.y1 + 1;
-
-            if (w < 3 || h < 3) return;
-
-            // Allocate 3 rows of buffer space.
-            m_buf.allocate(w * 3);
-
-            // Set up row pointers
-            pixel_type * begin = &m_buf[0];
-            pixel_type * r0 = begin;
-            pixel_type * r1 = r0 + w;
-            pixel_type * r2 = r1 + w;
-            pixel_type * end = r2 + w;
-
-            // Horizontally blur the first two input rows.
-            calc_row(img, bounds.x1, bounds.y1, w, r0);
-            memcpy(r1, r0, w * sizeof(pixel_type));
-
-            for (int y = 0; ; )
-            {
-                // Get pointer to first pixel.
-                pixel_type* p = img.pix_value_ptr(bounds.x1, bounds.y1 + y, bounds.x1 + w);
-
-                // Horizontally blur the row below.
-                if (y + 1 < h)
-                {
-                    calc_row(img, bounds.x1, bounds.y1 + y + 1, w, r2);
-                }
-                else
-                {
-                    memcpy(r2, r1, w * sizeof(pixel_type)); // duplicate bottom row
-                }
-
-                // Combine blurred rows into destination.
-                for (int x = 0; x < w; ++x)
-                {
-                    calc_pixel(*r0++, *r1++, *r2++, *p++);
-                }
-
-                if (++y >= h) break;
-
-                // Wrap bottom row pointer around to top of buffer.
-                if (r2 == end) r2 = begin;
-                else if (r1 == end) r1 = begin;
-                else if (r0 == end) r0 = begin;
-            }
-        }
-
-    private:
-        void calc_row(PixFmt& img, int x, int y, int w, pixel_type* row)
-        {
-            const int wm = w - 1;
-
-            pixel_type* p = img.pix_value_ptr(x, y, w);
-
-            pixel_type c[3];
-            pixel_type* p0 = c;
-            pixel_type* p1 = c + 1;
-            pixel_type* p2 = c + 2;
-            pixel_type* end = c + 3;
-            *p0 = *p1 = *p;
-
-            for (int x = 0; x < wm; ++x)
-            {
-                *p2 = *(p = p->next());
-
-                calc_pixel(*p0++, *p1++, *p2++, *row++);
-
-                if (p0 == end) p0 = c;
-                else if (p1 == end) p1 = c;
-                else if (p2 == end) p2 = c;
-            }
-
-            calc_pixel(*p0, *p1, *p1, *row);
-        }
-
-        void calc_pixel(
-            pixel_type const & c1,
-            pixel_type const & c2,
-            pixel_type const & c3,
-            pixel_type & x)
-        {
-            calc_pixel(c1, c2, c3, x, PixFmt::pixfmt_category());
-        }
-
-        void calc_pixel(
-            pixel_type const & c1,
-            pixel_type const & c2,
-            pixel_type const & c3,
-            pixel_type & x,
-            pixfmt_gray_tag)
-        {
-            x.c[0] = calc_value(c1.c[0], c2.c[0], c3.c[0]);
-        }
-
-        void calc_pixel(
-            pixel_type const & c1,
-            pixel_type const & c2,
-            pixel_type const & c3,
-            pixel_type & x,
-            pixfmt_rgb_tag)
-        {
-            enum { R = order_type::R, G = order_type::G, B = order_type::B };
-            x.c[R] = calc_value(c1.c[R], c2.c[R], c3.c[R]);
-            x.c[G] = calc_value(c1.c[G], c2.c[G], c3.c[G]);
-            x.c[B] = calc_value(c1.c[B], c2.c[B], c3.c[B]);
-        }
-
-        void calc_pixel(
-            pixel_type const & c1,
-            pixel_type const & c2,
-            pixel_type const & c3,
-            pixel_type & x,
-            pixfmt_rgba_tag)
-        {
-            enum { R = order_type::R, G = order_type::G, B = order_type::B, A = order_type::A };
-            x.c[R] = calc_value(c1.c[R], c2.c[R], c3.c[R]);
-            x.c[G] = calc_value(c1.c[G], c2.c[G], c3.c[G]);
-            x.c[B] = calc_value(c1.c[B], c2.c[B], c3.c[B]);
-            x.c[A] = calc_value(c1.c[A], c2.c[A], c3.c[A]);
-        }
-
-        value_type calc_value(value_type v1, value_type v2, value_type v3)
-        {
-            return value_type(m_g1 * v1 + m_g0 * v2 + m_g1 * v3);
-        }
-
-        double m_g0, m_g1;
-        pod_vector<pixel_type> m_buf;
-    };
-
-    // Helper functions for applying blur to a surface without having to create an intermediate object.
-
-    template<class PixFmt>
-    void apply_slight_blur(PixFmt& img, const rect_i& bounds, double r = 1)
-    {
-        if (r > 0) slight_blur<PixFmt>(r).blur(img, bounds);
-    }
-
-    template<class PixFmt>
-    void apply_slight_blur(PixFmt& img, double r = 1)
-    {
-        if (r > 0) slight_blur<PixFmt>(r).blur(img, rect_i(0, 0, img.width() - 1, img.height() - 1));
-    }
-
-    template<class PixFmt>
-    void apply_slight_blur(renderer_base<PixFmt>& img, const rect_i& bounds, double r = 1)
-    {
-        if (r > 0) slight_blur<PixFmt>(r).blur(img.ren(), bounds);
-    }
-
-    template<class PixFmt>
-    void apply_slight_blur(renderer_base<PixFmt>& img, double r = 1)
-    {
-        if (r > 0) slight_blur<PixFmt>(r).blur(img.ren(), img.clip_box());
-    }
-}
-
-
-
-
-#endif
diff --git a/xs/src/agg/agg_bounding_rect.h b/xs/src/agg/agg_bounding_rect.h
deleted file mode 100644
index f13b863f0..000000000
--- a/xs/src/agg/agg_bounding_rect.h
+++ /dev/null
@@ -1,116 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// bounding_rect function template
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_BOUNDING_RECT_INCLUDED
-#define AGG_BOUNDING_RECT_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //-----------------------------------------------------------bounding_rect
-    template<class VertexSource, class GetId, class CoordT>
-    bool bounding_rect(VertexSource& vs, GetId& gi, 
-                       unsigned start, unsigned num, 
-                       CoordT* x1, CoordT* y1, CoordT* x2, CoordT* y2)
-    {
-        unsigned i;
-        double x;
-        double y;
-        bool first = true;
-
-        *x1 = CoordT(1);
-        *y1 = CoordT(1);
-        *x2 = CoordT(0);
-        *y2 = CoordT(0);
-
-        for(i = 0; i < num; i++)
-        {
-            vs.rewind(gi[start + i]);
-            unsigned cmd;
-            while(!is_stop(cmd = vs.vertex(&x, &y)))
-            {
-                if(is_vertex(cmd))
-                {
-                    if(first)
-                    {
-                        *x1 = CoordT(x);
-                        *y1 = CoordT(y);
-                        *x2 = CoordT(x);
-                        *y2 = CoordT(y);
-                        first = false;
-                    }
-                    else
-                    {
-                        if(CoordT(x) < *x1) *x1 = CoordT(x);
-                        if(CoordT(y) < *y1) *y1 = CoordT(y);
-                        if(CoordT(x) > *x2) *x2 = CoordT(x);
-                        if(CoordT(y) > *y2) *y2 = CoordT(y);
-                    }
-                }
-            }
-        }
-        return *x1 <= *x2 && *y1 <= *y2;
-    }
-
-
-    //-----------------------------------------------------bounding_rect_single
-    template<class VertexSource, class CoordT> 
-    bool bounding_rect_single(VertexSource& vs, unsigned path_id,
-                              CoordT* x1, CoordT* y1, CoordT* x2, CoordT* y2)
-    {
-        double x;
-        double y;
-        bool first = true;
-
-        *x1 = CoordT(1);
-        *y1 = CoordT(1);
-        *x2 = CoordT(0);
-        *y2 = CoordT(0);
-
-        vs.rewind(path_id);
-        unsigned cmd;
-        while(!is_stop(cmd = vs.vertex(&x, &y)))
-        {
-            if(is_vertex(cmd))
-            {
-                if(first)
-                {
-                    *x1 = CoordT(x);
-                    *y1 = CoordT(y);
-                    *x2 = CoordT(x);
-                    *y2 = CoordT(y);
-                    first = false;
-                }
-                else
-                {
-                    if(CoordT(x) < *x1) *x1 = CoordT(x);
-                    if(CoordT(y) < *y1) *y1 = CoordT(y);
-                    if(CoordT(x) > *x2) *x2 = CoordT(x);
-                    if(CoordT(y) > *y2) *y2 = CoordT(y);
-                }
-            }
-        }
-        return *x1 <= *x2 && *y1 <= *y2;
-    }
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_bspline.h b/xs/src/agg/agg_bspline.h
deleted file mode 100644
index 2c1ed9a38..000000000
--- a/xs/src/agg/agg_bspline.h
+++ /dev/null
@@ -1,76 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// class bspline
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_BSPLINE_INCLUDED
-#define AGG_BSPLINE_INCLUDED
-
-#include "agg_array.h"
-
-namespace agg
-{
-    //----------------------------------------------------------------bspline
-    // A very simple class of Bi-cubic Spline interpolation.
-    // First call init(num, x[], y[]) where num - number of source points, 
-    // x, y - arrays of X and Y values respectively. Here Y must be a function 
-    // of X. It means that all the X-coordinates must be arranged in the ascending
-    // order. 
-    // Then call get(x) that calculates a value Y for the respective X. 
-    // The class supports extrapolation, i.e. you can call get(x) where x is
-    // outside the given with init() X-range. Extrapolation is a simple linear 
-    // function.
-    //
-    //  See Implementation agg_bspline.cpp
-    //------------------------------------------------------------------------
-    class bspline 
-    {
-    public:
-        bspline();
-        bspline(int num);
-        bspline(int num, const double* x, const double* y);
-
-        void   init(int num);
-        void   add_point(double x, double y);
-        void   prepare();
-
-        void   init(int num, const double* x, const double* y);
-
-        double get(double x) const;
-        double get_stateful(double x) const;
-    
-    private:
-        bspline(const bspline&);
-        const bspline& operator = (const bspline&);
-
-        static void bsearch(int n, const double *x, double x0, int *i);
-        double extrapolation_left(double x) const;
-        double extrapolation_right(double x) const;
-        double interpolation(double x, int i) const;
-
-        int               m_max;
-        int               m_num;
-        double*           m_x;
-        double*           m_y;
-        pod_array<double> m_am;
-        mutable int       m_last_idx;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_adaptor_vcgen.h b/xs/src/agg/agg_conv_adaptor_vcgen.h
deleted file mode 100644
index a79f2208c..000000000
--- a/xs/src/agg/agg_conv_adaptor_vcgen.h
+++ /dev/null
@@ -1,157 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_ADAPTOR_VCGEN_INCLUDED
-#define AGG_CONV_ADAPTOR_VCGEN_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //------------------------------------------------------------null_markers
-    struct null_markers
-    {
-        void remove_all() {}
-        void add_vertex(double, double, unsigned) {}
-        void prepare_src() {}
-
-        void rewind(unsigned) {}
-        unsigned vertex(double*, double*) { return path_cmd_stop; }
-    };
-
-
-    //------------------------------------------------------conv_adaptor_vcgen
-    template<class VertexSource, 
-             class Generator, 
-             class Markers=null_markers> class conv_adaptor_vcgen
-    {
-        enum status
-        {
-            initial,
-            accumulate,
-            generate
-        };
-
-    public:
-        explicit conv_adaptor_vcgen(VertexSource& source) :
-            m_source(&source), 
-            m_status(initial)
-        {}
-        void attach(VertexSource& source) { m_source = &source; }
-
-        Generator& generator() { return m_generator; }
-        const Generator& generator() const { return m_generator; }
-
-        Markers& markers() { return m_markers; }
-        const Markers& markers() const { return m_markers; }
-        
-        void rewind(unsigned path_id) 
-        { 
-            m_source->rewind(path_id); 
-            m_status = initial;
-        }
-
-        unsigned vertex(double* x, double* y);
-
-    private:
-        // Prohibit copying
-        conv_adaptor_vcgen(const conv_adaptor_vcgen<VertexSource, Generator, Markers>&);
-        const conv_adaptor_vcgen<VertexSource, Generator, Markers>& 
-            operator = (const conv_adaptor_vcgen<VertexSource, Generator, Markers>&);
-
-        VertexSource* m_source;
-        Generator     m_generator;
-        Markers       m_markers;
-        status        m_status;
-        unsigned      m_last_cmd;
-        double        m_start_x;
-        double        m_start_y;
-    };
-
-
-
-
-
-    //------------------------------------------------------------------------
-    template<class VertexSource, class Generator, class Markers> 
-    unsigned conv_adaptor_vcgen<VertexSource, Generator, Markers>::vertex(double* x, double* y)
-    {
-        unsigned cmd = path_cmd_stop;
-        bool done = false;
-        while(!done)
-        {
-            switch(m_status)
-            {
-            case initial:
-                m_markers.remove_all();
-                m_last_cmd = m_source->vertex(&m_start_x, &m_start_y);
-                m_status = accumulate;
-
-            case accumulate:
-                if(is_stop(m_last_cmd)) return path_cmd_stop;
-
-                m_generator.remove_all();
-                m_generator.add_vertex(m_start_x, m_start_y, path_cmd_move_to);
-                m_markers.add_vertex(m_start_x, m_start_y, path_cmd_move_to);
-
-                for(;;)
-                {
-                    cmd = m_source->vertex(x, y);
-                    if(is_vertex(cmd))
-                    {
-                        m_last_cmd = cmd;
-                        if(is_move_to(cmd))
-                        {
-                            m_start_x = *x;
-                            m_start_y = *y;
-                            break;
-                        }
-                        m_generator.add_vertex(*x, *y, cmd);
-                        m_markers.add_vertex(*x, *y, path_cmd_line_to);
-                    }
-                    else
-                    {
-                        if(is_stop(cmd))
-                        {
-                            m_last_cmd = path_cmd_stop;
-                            break;
-                        }
-                        if(is_end_poly(cmd))
-                        {
-                            m_generator.add_vertex(*x, *y, cmd);
-                            break;
-                        }
-                    }
-                }
-                m_generator.rewind(0);
-                m_status = generate;
-
-            case generate:
-                cmd = m_generator.vertex(x, y);
-                if(is_stop(cmd))
-                {
-                    m_status = accumulate;
-                    break;
-                }
-                done = true;
-                break;
-            }
-        }
-        return cmd;
-    }
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_adaptor_vpgen.h b/xs/src/agg/agg_conv_adaptor_vpgen.h
deleted file mode 100644
index d6b545ef1..000000000
--- a/xs/src/agg/agg_conv_adaptor_vpgen.h
+++ /dev/null
@@ -1,159 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_ADAPTOR_VPGEN_INCLUDED
-#define AGG_CONV_ADAPTOR_VPGEN_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //======================================================conv_adaptor_vpgen
-    template<class VertexSource, class VPGen> class conv_adaptor_vpgen
-    {
-    public:
-        explicit conv_adaptor_vpgen(VertexSource& source) : m_source(&source) {}
-        void attach(VertexSource& source) { m_source = &source; }
-
-        VPGen& vpgen() { return m_vpgen; }
-        const VPGen& vpgen() const { return m_vpgen; }
-
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        conv_adaptor_vpgen(const conv_adaptor_vpgen<VertexSource, VPGen>&);
-        const conv_adaptor_vpgen<VertexSource, VPGen>& 
-            operator = (const conv_adaptor_vpgen<VertexSource, VPGen>&);
-
-        VertexSource* m_source;
-        VPGen         m_vpgen;
-        double        m_start_x;
-        double        m_start_y;
-        unsigned      m_poly_flags;
-        int           m_vertices;
-    };
-
-
-
-    //------------------------------------------------------------------------
-    template<class VertexSource, class VPGen>
-    void conv_adaptor_vpgen<VertexSource, VPGen>::rewind(unsigned path_id) 
-    { 
-        m_source->rewind(path_id);
-        m_vpgen.reset();
-        m_start_x    = 0;
-        m_start_y    = 0;
-        m_poly_flags = 0;
-        m_vertices   = 0;
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VertexSource, class VPGen>
-    unsigned conv_adaptor_vpgen<VertexSource, VPGen>::vertex(double* x, double* y)
-    {
-        unsigned cmd = path_cmd_stop;
-        for(;;)
-        {
-            cmd = m_vpgen.vertex(x, y);
-            if(!is_stop(cmd)) break;
-
-            if(m_poly_flags && !m_vpgen.auto_unclose())
-            {
-                *x = 0.0;
-                *y = 0.0;
-                cmd = m_poly_flags;
-                m_poly_flags = 0;
-                break;
-            }
-
-            if(m_vertices < 0)
-            {
-                if(m_vertices < -1) 
-                {
-                    m_vertices = 0;
-                    return path_cmd_stop;
-                }
-                m_vpgen.move_to(m_start_x, m_start_y);
-                m_vertices = 1;
-                continue;
-            }
-
-            double tx, ty;
-            cmd = m_source->vertex(&tx, &ty);
-            if(is_vertex(cmd))
-            {
-                if(is_move_to(cmd)) 
-                {
-                    if(m_vpgen.auto_close() && m_vertices > 2)
-                    {
-                        m_vpgen.line_to(m_start_x, m_start_y);
-                        m_poly_flags = path_cmd_end_poly | path_flags_close;
-                        m_start_x    = tx;
-                        m_start_y    = ty;
-                        m_vertices   = -1;
-                        continue;
-                    }
-                    m_vpgen.move_to(tx, ty);
-                    m_start_x  = tx;
-                    m_start_y  = ty;
-                    m_vertices = 1;
-                }
-                else 
-                {
-                    m_vpgen.line_to(tx, ty);
-                    ++m_vertices;
-                }
-            }
-            else
-            {
-                if(is_end_poly(cmd))
-                {
-                    m_poly_flags = cmd;
-                    if(is_closed(cmd) || m_vpgen.auto_close())
-                    {
-                        if(m_vpgen.auto_close()) m_poly_flags |= path_flags_close;
-                        if(m_vertices > 2)
-                        {
-                            m_vpgen.line_to(m_start_x, m_start_y);
-                        }
-                        m_vertices = 0;
-                    }
-                }
-                else
-                {
-                    // path_cmd_stop
-                    if(m_vpgen.auto_close() && m_vertices > 2)
-                    {
-                        m_vpgen.line_to(m_start_x, m_start_y);
-                        m_poly_flags = path_cmd_end_poly | path_flags_close;
-                        m_vertices   = -2;
-                        continue;
-                    }
-                    break;
-                }
-            }
-        }
-        return cmd;
-    }
-
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_conv_bspline.h b/xs/src/agg/agg_conv_bspline.h
deleted file mode 100644
index 13d22d929..000000000
--- a/xs/src/agg/agg_conv_bspline.h
+++ /dev/null
@@ -1,48 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_BSPLINE_INCLUDED
-#define AGG_CONV_BSPLINE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vcgen_bspline.h"
-#include "agg_conv_adaptor_vcgen.h"
-
-
-namespace agg
-{
-
-    //---------------------------------------------------------conv_bspline
-    template<class VertexSource> 
-    struct conv_bspline : public conv_adaptor_vcgen<VertexSource, vcgen_bspline>
-    {
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_bspline> base_type;
-
-        conv_bspline(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_bspline>(vs) {}
-
-        void   interpolation_step(double v) { base_type::generator().interpolation_step(v); }
-        double interpolation_step() const { return base_type::generator().interpolation_step(); }
-
-    private:
-        conv_bspline(const conv_bspline<VertexSource>&);
-        const conv_bspline<VertexSource>& 
-            operator = (const conv_bspline<VertexSource>&);
-    };
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_conv_clip_polygon.h b/xs/src/agg/agg_conv_clip_polygon.h
deleted file mode 100644
index 87537638d..000000000
--- a/xs/src/agg/agg_conv_clip_polygon.h
+++ /dev/null
@@ -1,63 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Polygon clipping converter
-// There an optimized Liang-Basky algorithm is used. 
-// The algorithm doesn't optimize the degenerate edges, i.e. it will never
-// break a closed polygon into two or more ones, instead, there will be 
-// degenerate edges coinciding with the respective clipping boundaries.
-// This is a sub-optimal solution, because that optimization would require 
-// extra, rather expensive math while the rasterizer tolerates it quite well, 
-// without any considerable overhead.
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_CLIP_POLYGON_INCLUDED
-#define AGG_CONV_CLIP_POLYGON_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_conv_adaptor_vpgen.h"
-#include "agg_vpgen_clip_polygon.h"
-
-namespace agg
-{
-
-    //=======================================================conv_clip_polygon
-    template<class VertexSource> 
-    struct conv_clip_polygon : public conv_adaptor_vpgen<VertexSource, vpgen_clip_polygon>
-    {
-        typedef conv_adaptor_vpgen<VertexSource, vpgen_clip_polygon> base_type;
-
-        conv_clip_polygon(VertexSource& vs) : 
-            conv_adaptor_vpgen<VertexSource, vpgen_clip_polygon>(vs) {}
-
-        void clip_box(double x1, double y1, double x2, double y2)
-        {
-            base_type::vpgen().clip_box(x1, y1, x2, y2);
-        }
-
-        double x1() const { return base_type::vpgen().x1(); }
-        double y1() const { return base_type::vpgen().y1(); }
-        double x2() const { return base_type::vpgen().x2(); }
-        double y2() const { return base_type::vpgen().y2(); }
-
-    private:
-        conv_clip_polygon(const conv_clip_polygon<VertexSource>&);
-        const conv_clip_polygon<VertexSource>& 
-            operator = (const conv_clip_polygon<VertexSource>&);
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_clip_polyline.h b/xs/src/agg/agg_conv_clip_polyline.h
deleted file mode 100644
index f3fc2888c..000000000
--- a/xs/src/agg/agg_conv_clip_polyline.h
+++ /dev/null
@@ -1,63 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// polyline clipping converter
-// There an optimized Liang-Basky algorithm is used. 
-// The algorithm doesn't optimize the degenerate edges, i.e. it will never
-// break a closed polyline into two or more ones, instead, there will be 
-// degenerate edges coinciding with the respective clipping boundaries.
-// This is a sub-optimal solution, because that optimization would require 
-// extra, rather expensive math while the rasterizer tolerates it quite well, 
-// without any considerable overhead.
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_CLIP_polyline_INCLUDED
-#define AGG_CONV_CLIP_polyline_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_conv_adaptor_vpgen.h"
-#include "agg_vpgen_clip_polyline.h"
-
-namespace agg
-{
-
-    //=======================================================conv_clip_polyline
-    template<class VertexSource> 
-    struct conv_clip_polyline : public conv_adaptor_vpgen<VertexSource, vpgen_clip_polyline>
-    {
-        typedef conv_adaptor_vpgen<VertexSource, vpgen_clip_polyline> base_type;
-
-        conv_clip_polyline(VertexSource& vs) : 
-            conv_adaptor_vpgen<VertexSource, vpgen_clip_polyline>(vs) {}
-
-        void clip_box(double x1, double y1, double x2, double y2)
-        {
-            base_type::vpgen().clip_box(x1, y1, x2, y2);
-        }
-
-        double x1() const { return base_type::vpgen().x1(); }
-        double y1() const { return base_type::vpgen().y1(); }
-        double x2() const { return base_type::vpgen().x2(); }
-        double y2() const { return base_type::vpgen().y2(); }
-
-    private:
-        conv_clip_polyline(const conv_clip_polyline<VertexSource>&);
-        const conv_clip_polyline<VertexSource>& 
-            operator = (const conv_clip_polyline<VertexSource>&);
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_close_polygon.h b/xs/src/agg/agg_conv_close_polygon.h
deleted file mode 100644
index c46594fdf..000000000
--- a/xs/src/agg/agg_conv_close_polygon.h
+++ /dev/null
@@ -1,125 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_CLOSE_POLYGON_INCLUDED
-#define AGG_CONV_CLOSE_POLYGON_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //======================================================conv_close_polygon
-    template<class VertexSource> class conv_close_polygon
-    {
-    public:
-        explicit conv_close_polygon(VertexSource& vs) : m_source(&vs) {}
-        void attach(VertexSource& source) { m_source = &source; }
-
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        conv_close_polygon(const conv_close_polygon<VertexSource>&);
-        const conv_close_polygon<VertexSource>& 
-            operator = (const conv_close_polygon<VertexSource>&);
-
-        VertexSource* m_source;
-        unsigned      m_cmd[2];
-        double        m_x[2];
-        double        m_y[2];
-        unsigned      m_vertex;
-        bool          m_line_to;
-    };
-
-
-
-    //------------------------------------------------------------------------
-    template<class VertexSource> 
-    void conv_close_polygon<VertexSource>::rewind(unsigned path_id)
-    {
-        m_source->rewind(path_id);
-        m_vertex = 2;
-        m_line_to = false;
-    }
-
-
-    
-    //------------------------------------------------------------------------
-    template<class VertexSource> 
-    unsigned conv_close_polygon<VertexSource>::vertex(double* x, double* y)
-    {
-        unsigned cmd = path_cmd_stop;
-        for(;;)
-        {
-            if(m_vertex < 2)
-            {
-                *x = m_x[m_vertex];
-                *y = m_y[m_vertex];
-                cmd = m_cmd[m_vertex];
-                ++m_vertex;
-                break;
-            }
-
-            cmd = m_source->vertex(x, y);
-
-            if(is_end_poly(cmd))
-            {
-                cmd |= path_flags_close;
-                break;
-            }
-
-            if(is_stop(cmd))
-            {
-                if(m_line_to)
-                {
-                    m_cmd[0]  = path_cmd_end_poly | path_flags_close;
-                    m_cmd[1]  = path_cmd_stop;
-                    m_vertex  = 0;
-                    m_line_to = false;
-                    continue;
-                }
-                break;
-            }
-
-            if(is_move_to(cmd))
-            {
-                if(m_line_to)
-                {
-                    m_x[0]    = 0.0;
-                    m_y[0]    = 0.0;
-                    m_cmd[0]  = path_cmd_end_poly | path_flags_close;
-                    m_x[1]    = *x;
-                    m_y[1]    = *y;
-                    m_cmd[1]  = cmd;
-                    m_vertex  = 0;
-                    m_line_to = false;
-                    continue;
-                }
-                break;
-            }
-
-            if(is_vertex(cmd))
-            {
-                m_line_to = true;
-                break;
-            }
-        }
-        return cmd;
-    }
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_concat.h b/xs/src/agg/agg_conv_concat.h
deleted file mode 100644
index 745d349c6..000000000
--- a/xs/src/agg/agg_conv_concat.h
+++ /dev/null
@@ -1,73 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_CONCAT_INCLUDED
-#define AGG_CONV_CONCAT_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //=============================================================conv_concat
-    // Concatenation of two paths. Usually used to combine lines or curves 
-    // with markers such as arrowheads
-    template<class VS1, class VS2> class conv_concat
-    {
-    public:
-        conv_concat(VS1& source1, VS2& source2) :
-            m_source1(&source1), m_source2(&source2), m_status(2) {}
-        void attach1(VS1& source) { m_source1 = &source; }
-        void attach2(VS2& source) { m_source2 = &source; }
-
-
-        void rewind(unsigned path_id)
-        { 
-            m_source1->rewind(path_id);
-            m_source2->rewind(0);
-            m_status = 0;
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            unsigned cmd;
-            if(m_status == 0)
-            {
-                cmd = m_source1->vertex(x, y);
-                if(!is_stop(cmd)) return cmd;
-                m_status = 1;
-            }
-            if(m_status == 1)
-            {
-                cmd = m_source2->vertex(x, y);
-                if(!is_stop(cmd)) return cmd;
-                m_status = 2;
-            }
-            return path_cmd_stop;
-        }
-
-    private:
-        conv_concat(const conv_concat<VS1, VS2>&);
-        const conv_concat<VS1, VS2>& 
-            operator = (const conv_concat<VS1, VS2>&);
-
-        VS1* m_source1;
-        VS2* m_source2;
-        int  m_status;
-
-    };
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_conv_contour.h b/xs/src/agg/agg_conv_contour.h
deleted file mode 100644
index b4b5a9047..000000000
--- a/xs/src/agg/agg_conv_contour.h
+++ /dev/null
@@ -1,65 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// conv_stroke
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_CONTOUR_INCLUDED
-#define AGG_CONV_CONTOUR_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vcgen_contour.h"
-#include "agg_conv_adaptor_vcgen.h"
-
-namespace agg
-{
-
-    //-----------------------------------------------------------conv_contour
-    template<class VertexSource> 
-    struct conv_contour : public conv_adaptor_vcgen<VertexSource, vcgen_contour>
-    {
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_contour> base_type;
-
-        conv_contour(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_contour>(vs)
-        {
-        }
-
-        void line_join(line_join_e lj) { base_type::generator().line_join(lj); }
-        void inner_join(inner_join_e ij) { base_type::generator().inner_join(ij); }
-        void width(double w) { base_type::generator().width(w); }
-        void miter_limit(double ml) { base_type::generator().miter_limit(ml); }
-        void miter_limit_theta(double t) { base_type::generator().miter_limit_theta(t); }
-        void inner_miter_limit(double ml) { base_type::generator().inner_miter_limit(ml); }
-        void approximation_scale(double as) { base_type::generator().approximation_scale(as); }
-        void auto_detect_orientation(bool v) { base_type::generator().auto_detect_orientation(v); }
-
-        line_join_e line_join() const { return base_type::generator().line_join(); }
-        inner_join_e inner_join() const { return base_type::generator().inner_join(); }
-        double width() const { return base_type::generator().width(); }
-        double miter_limit() const { return base_type::generator().miter_limit(); }
-        double inner_miter_limit() const { return base_type::generator().inner_miter_limit(); }
-        double approximation_scale() const { return base_type::generator().approximation_scale(); }
-        bool auto_detect_orientation() const { return base_type::generator().auto_detect_orientation(); }
-
-    private:
-        conv_contour(const conv_contour<VertexSource>&);
-        const conv_contour<VertexSource>& 
-            operator = (const conv_contour<VertexSource>&);
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_curve.h b/xs/src/agg/agg_conv_curve.h
deleted file mode 100644
index 0be3b6fd7..000000000
--- a/xs/src/agg/agg_conv_curve.h
+++ /dev/null
@@ -1,201 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// classes conv_curve
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_CURVE_INCLUDED
-#define AGG_CONV_CURVE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_curves.h"
-
-namespace agg
-{
-
-
-    //---------------------------------------------------------------conv_curve
-    // Curve converter class. Any path storage can have Bezier curves defined 
-    // by their control points. There're two types of curves supported: curve3 
-    // and curve4. Curve3 is a conic Bezier curve with 2 endpoints and 1 control
-    // point. Curve4 has 2 control points (4 points in total) and can be used
-    // to interpolate more complicated curves. Curve4, unlike curve3 can be used 
-    // to approximate arcs, both circular and elliptical. Curves are approximated 
-    // with straight lines and one of the approaches is just to store the whole 
-    // sequence of vertices that approximate our curve. It takes additional 
-    // memory, and at the same time the consecutive vertices can be calculated 
-    // on demand. 
-    //
-    // Initially, path storages are not suppose to keep all the vertices of the
-    // curves (although, nothing prevents us from doing so). Instead, path_storage
-    // keeps only vertices, needed to calculate a curve on demand. Those vertices
-    // are marked with special commands. So, if the path_storage contains curves 
-    // (which are not real curves yet), and we render this storage directly, 
-    // all we will see is only 2 or 3 straight line segments (for curve3 and 
-    // curve4 respectively). If we need to see real curves drawn we need to 
-    // include this class into the conversion pipeline. 
-    //
-    // Class conv_curve recognizes commands path_cmd_curve3 and path_cmd_curve4 
-    // and converts these vertices into a move_to/line_to sequence. 
-    //-----------------------------------------------------------------------
-    template<class VertexSource, 
-             class Curve3=curve3, 
-             class Curve4=curve4> class conv_curve
-    {
-    public:
-        typedef Curve3 curve3_type;
-        typedef Curve4 curve4_type;
-        typedef conv_curve<VertexSource, Curve3, Curve4> self_type;
-
-        explicit conv_curve(VertexSource& source) :
-          m_source(&source), m_last_x(0.0), m_last_y(0.0) {}
-        void attach(VertexSource& source) { m_source = &source; }
-
-        void approximation_method(curve_approximation_method_e v) 
-        { 
-            m_curve3.approximation_method(v);
-            m_curve4.approximation_method(v);
-        }
-
-        curve_approximation_method_e approximation_method() const 
-        { 
-            return m_curve4.approximation_method();
-        }
-
-        void approximation_scale(double s) 
-        { 
-            m_curve3.approximation_scale(s); 
-            m_curve4.approximation_scale(s); 
-        }
-
-        double approximation_scale() const 
-        { 
-            return m_curve4.approximation_scale();  
-        }
-
-        void angle_tolerance(double v) 
-        { 
-            m_curve3.angle_tolerance(v); 
-            m_curve4.angle_tolerance(v); 
-        }
-
-        double angle_tolerance() const 
-        { 
-            return m_curve4.angle_tolerance();  
-        }
-
-        void cusp_limit(double v) 
-        { 
-            m_curve3.cusp_limit(v); 
-            m_curve4.cusp_limit(v); 
-        }
-
-        double cusp_limit() const 
-        { 
-            return m_curve4.cusp_limit();  
-        }
-
-        void     rewind(unsigned path_id); 
-        unsigned vertex(double* x, double* y);
-
-    private:
-        conv_curve(const self_type&);
-        const self_type& operator = (const self_type&);
-
-        VertexSource* m_source;
-        double        m_last_x;
-        double        m_last_y;
-        curve3_type   m_curve3;
-        curve4_type   m_curve4;
-    };
-
-
-
-    //------------------------------------------------------------------------
-    template<class VertexSource, class Curve3, class Curve4>
-    void conv_curve<VertexSource, Curve3, Curve4>::rewind(unsigned path_id)
-    {
-        m_source->rewind(path_id);
-        m_last_x = 0.0;
-        m_last_y = 0.0;
-        m_curve3.reset();
-        m_curve4.reset();
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VertexSource, class Curve3, class Curve4>
-    unsigned conv_curve<VertexSource, Curve3, Curve4>::vertex(double* x, double* y)
-    {
-        if(!is_stop(m_curve3.vertex(x, y)))
-        {
-            m_last_x = *x;
-            m_last_y = *y;
-            return path_cmd_line_to;
-        }
-
-        if(!is_stop(m_curve4.vertex(x, y)))
-        {
-            m_last_x = *x;
-            m_last_y = *y;
-            return path_cmd_line_to;
-        }
-
-        double ct2_x = 0;
-        double ct2_y = 0;
-        double end_x = 0;
-        double end_y = 0;
-
-        unsigned cmd = m_source->vertex(x, y);
-        switch(cmd)
-        {
-        case path_cmd_curve3:
-            m_source->vertex(&end_x, &end_y);
-
-            m_curve3.init(m_last_x, m_last_y, 
-                          *x,       *y, 
-                          end_x,     end_y);
-
-            m_curve3.vertex(x, y);    // First call returns path_cmd_move_to
-            m_curve3.vertex(x, y);    // This is the first vertex of the curve
-            cmd = path_cmd_line_to;
-            break;
-
-        case path_cmd_curve4:
-            m_source->vertex(&ct2_x, &ct2_y);
-            m_source->vertex(&end_x, &end_y);
-
-            m_curve4.init(m_last_x, m_last_y, 
-                          *x,       *y, 
-                          ct2_x,    ct2_y, 
-                          end_x,    end_y);
-
-            m_curve4.vertex(x, y);    // First call returns path_cmd_move_to
-            m_curve4.vertex(x, y);    // This is the first vertex of the curve
-            cmd = path_cmd_line_to;
-            break;
-        }
-        m_last_x = *x;
-        m_last_y = *y;
-        return cmd;
-    }
-
-
-}
-
-
-
-#endif
diff --git a/xs/src/agg/agg_conv_dash.h b/xs/src/agg/agg_conv_dash.h
deleted file mode 100644
index 23c13ad0a..000000000
--- a/xs/src/agg/agg_conv_dash.h
+++ /dev/null
@@ -1,68 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// conv_dash
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_DASH_INCLUDED
-#define AGG_CONV_DASH_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vcgen_dash.h"
-#include "agg_conv_adaptor_vcgen.h"
-
-namespace agg
-{
-
-    //---------------------------------------------------------------conv_dash
-    template<class VertexSource, class Markers=null_markers> 
-    struct conv_dash : public conv_adaptor_vcgen<VertexSource, vcgen_dash, Markers>
-    {
-        typedef Markers marker_type;
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_dash, Markers> base_type;
-
-        conv_dash(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_dash, Markers>(vs)
-        {
-        }
-
-        void remove_all_dashes() 
-        { 
-            base_type::generator().remove_all_dashes(); 
-        }
-
-        void add_dash(double dash_len, double gap_len) 
-        { 
-            base_type::generator().add_dash(dash_len, gap_len); 
-        }
-
-        void dash_start(double ds) 
-        { 
-            base_type::generator().dash_start(ds); 
-        }
-
-        void shorten(double s) { base_type::generator().shorten(s); }
-        double shorten() const { return base_type::generator().shorten(); }
-
-    private:
-        conv_dash(const conv_dash<VertexSource, Markers>&);
-        const conv_dash<VertexSource, Markers>& 
-            operator = (const conv_dash<VertexSource, Markers>&);
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_gpc.h b/xs/src/agg/agg_conv_gpc.h
deleted file mode 100644
index 698ae900f..000000000
--- a/xs/src/agg/agg_conv_gpc.h
+++ /dev/null
@@ -1,432 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// General Polygon Clipper based on the GPC library by Alan Murta 
-// Union, Intersection, XOR, A-B, B-A
-// Contact the author if you intend to use it in commercial applications!
-// http://www.cs.man.ac.uk/aig/staff/alan/software/
-// Alan Murta (email: gpc@cs.man.ac.uk)
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_GPC_INCLUDED
-#define AGG_CONV_GPC_INCLUDED
-
-#include <math.h>
-#include "agg_basics.h"
-#include "agg_array.h"
-
-extern "C" 
-{ 
-#include "gpc.h" 
-}
-
-namespace agg
-{
-    enum gpc_op_e
-    {
-        gpc_or,
-        gpc_and,
-        gpc_xor,
-        gpc_a_minus_b,
-        gpc_b_minus_a
-    };
-
-
-    //================================================================conv_gpc
-    template<class VSA, class VSB> class conv_gpc
-    {
-        enum status
-        {
-            status_move_to,
-            status_line_to,
-            status_stop
-        };
-
-        struct contour_header_type
-        {
-            int num_vertices;
-            int hole_flag;
-            gpc_vertex* vertices;
-        };
-
-        typedef pod_bvector<gpc_vertex, 8>          vertex_array_type;
-        typedef pod_bvector<contour_header_type, 6> contour_header_array_type;
-
-
-    public:
-        typedef VSA source_a_type;
-        typedef VSB source_b_type;
-        typedef conv_gpc<source_a_type, source_b_type> self_type;
-
-        ~conv_gpc()
-        {
-            free_gpc_data();
-        }
-
-        conv_gpc(source_a_type& a, source_b_type& b, gpc_op_e op = gpc_or) :
-            m_src_a(&a),
-            m_src_b(&b),
-            m_status(status_move_to),
-            m_vertex(-1),
-            m_contour(-1),
-            m_operation(op)
-        {
-            memset(&m_poly_a, 0, sizeof(m_poly_a));
-            memset(&m_poly_b, 0, sizeof(m_poly_b));
-            memset(&m_result, 0, sizeof(m_result));
-        }
-
-        void attach1(VSA& source) { m_src_a = &source; }
-        void attach2(VSB& source) { m_src_b = &source; }
-
-        void operation(gpc_op_e v) { m_operation = v; }
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        conv_gpc(const conv_gpc<VSA, VSB>&);
-        const conv_gpc<VSA, VSB>& operator = (const conv_gpc<VSA, VSB>&);
-
-        //--------------------------------------------------------------------
-        void free_polygon(gpc_polygon& p);
-        void free_result();
-        void free_gpc_data();
-        void start_contour();
-        void add_vertex(double x, double y);
-        void end_contour(unsigned orientation);
-        void make_polygon(gpc_polygon& p);
-        void start_extracting();
-        bool next_contour();
-        bool next_vertex(double* x, double* y);
-
-
-        //--------------------------------------------------------------------
-        template<class VS> void add(VS& src, gpc_polygon& p)
-        {
-            unsigned cmd;
-            double x, y;
-            double start_x = 0.0;
-            double start_y = 0.0;
-            bool line_to = false;
-            unsigned orientation = 0;
-
-            m_contour_accumulator.remove_all();
-
-            while(!is_stop(cmd = src.vertex(&x, &y)))
-            {
-                if(is_vertex(cmd))
-                {
-                    if(is_move_to(cmd))
-                    {
-                        if(line_to)
-                        {
-                            end_contour(orientation);
-                            orientation = 0;
-                        }
-                        start_contour();
-                        start_x = x;
-                        start_y = y;
-                    }
-                    add_vertex(x, y);
-                    line_to = true;
-                }
-                else
-                {
-                    if(is_end_poly(cmd))
-                    {
-                        orientation = get_orientation(cmd);
-                        if(line_to && is_closed(cmd))
-                        {
-                            add_vertex(start_x, start_y);
-                        }
-                    }
-                }
-            }
-            if(line_to)
-            {
-                end_contour(orientation);
-            }
-            make_polygon(p);
-        }
-
-
-    private:
-        //--------------------------------------------------------------------
-        source_a_type*             m_src_a;
-        source_b_type*             m_src_b;
-        status                     m_status;
-        int                        m_vertex;
-        int                        m_contour;
-        gpc_op_e                   m_operation;
-        vertex_array_type          m_vertex_accumulator;
-        contour_header_array_type  m_contour_accumulator;
-        gpc_polygon                m_poly_a;
-        gpc_polygon                m_poly_b;
-        gpc_polygon                m_result;
-    };
-
-
-
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::free_polygon(gpc_polygon& p)
-    {
-        int i;
-        for(i = 0; i < p.num_contours; i++)
-        {
-            pod_allocator<gpc_vertex>::deallocate(p.contour[i].vertex, 
-                                                  p.contour[i].num_vertices);
-        }
-        pod_allocator<gpc_vertex_list>::deallocate(p.contour, p.num_contours);
-        memset(&p, 0, sizeof(gpc_polygon));
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::free_result()
-    {
-        if(m_result.contour)
-        {
-            gpc_free_polygon(&m_result);
-        }
-        memset(&m_result, 0, sizeof(m_result));
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::free_gpc_data()
-    {
-        free_polygon(m_poly_a);
-        free_polygon(m_poly_b);
-        free_result();
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::start_contour()
-    {
-        contour_header_type h;
-        memset(&h, 0, sizeof(h));
-        m_contour_accumulator.add(h);
-        m_vertex_accumulator.remove_all();
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    inline void conv_gpc<VSA, VSB>::add_vertex(double x, double y)
-    {
-        gpc_vertex v;
-        v.x = x;
-        v.y = y;
-        m_vertex_accumulator.add(v);
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::end_contour(unsigned /*orientation*/)
-    {
-        if(m_contour_accumulator.size())
-        {
-            if(m_vertex_accumulator.size() > 2)
-            {
-                contour_header_type& h = 
-                    m_contour_accumulator[m_contour_accumulator.size() - 1];
-
-                h.num_vertices = m_vertex_accumulator.size();
-                h.hole_flag = 0;
-
-                // TO DO: Clarify the "holes"
-                //if(is_cw(orientation)) h.hole_flag = 1;
-
-                h.vertices = pod_allocator<gpc_vertex>::allocate(h.num_vertices);
-                gpc_vertex* d = h.vertices;
-                int i;
-                for(i = 0; i < h.num_vertices; i++)
-                {
-                    const gpc_vertex& s = m_vertex_accumulator[i];
-                    d->x = s.x;
-                    d->y = s.y;
-                    ++d;
-                }
-            }
-            else
-            {
-                m_vertex_accumulator.remove_last();
-            }
-        }
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::make_polygon(gpc_polygon& p)
-    {
-        free_polygon(p);
-        if(m_contour_accumulator.size())
-        {
-            p.num_contours = m_contour_accumulator.size();
-
-            p.hole = 0;
-            p.contour = pod_allocator<gpc_vertex_list>::allocate(p.num_contours);
-
-            int i;
-            gpc_vertex_list* pv = p.contour;
-            for(i = 0; i < p.num_contours; i++)
-            {
-                const contour_header_type& h = m_contour_accumulator[i];
-                pv->num_vertices = h.num_vertices;
-                pv->vertex = h.vertices;
-                ++pv;
-            }
-        }
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::start_extracting()
-    {
-        m_status = status_move_to;
-        m_contour = -1;
-        m_vertex = -1;
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    bool conv_gpc<VSA, VSB>::next_contour()
-    {
-        if(++m_contour < m_result.num_contours)
-        {
-            m_vertex = -1;
-            return true;
-        }
-        return false;
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    inline bool conv_gpc<VSA, VSB>::next_vertex(double* x, double* y)
-    {
-        const gpc_vertex_list& vlist = m_result.contour[m_contour];
-        if(++m_vertex < vlist.num_vertices)
-        {
-            const gpc_vertex& v = vlist.vertex[m_vertex];
-            *x = v.x;
-            *y = v.y;
-            return true;
-        }
-        return false;
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    void conv_gpc<VSA, VSB>::rewind(unsigned path_id)
-    {
-        free_result();
-        m_src_a->rewind(path_id);
-        m_src_b->rewind(path_id);
-        add(*m_src_a, m_poly_a);
-        add(*m_src_b, m_poly_b);
-        switch(m_operation)
-        {
-           case gpc_or:
-                gpc_polygon_clip(GPC_UNION,
-                                 &m_poly_a,
-                                 &m_poly_b,
-                                 &m_result);
-               break;
-
-           case gpc_and:
-                gpc_polygon_clip(GPC_INT,
-                                 &m_poly_a,
-                                 &m_poly_b,
-                                 &m_result);
-               break;
-
-           case gpc_xor:
-                gpc_polygon_clip(GPC_XOR,
-                                 &m_poly_a,
-                                 &m_poly_b,
-                                 &m_result);
-               break;
-
-           case gpc_a_minus_b:
-                gpc_polygon_clip(GPC_DIFF,
-                                 &m_poly_a,
-                                 &m_poly_b,
-                                 &m_result);
-               break;
-
-           case gpc_b_minus_a:
-                gpc_polygon_clip(GPC_DIFF,
-                                 &m_poly_b,
-                                 &m_poly_a,
-                                 &m_result);
-               break;
-        }
-        start_extracting();
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class VSA, class VSB> 
-    unsigned conv_gpc<VSA, VSB>::vertex(double* x, double* y)
-    {
-        if(m_status == status_move_to)
-        {
-            if(next_contour()) 
-            {
-                if(next_vertex(x, y))
-                {
-                    m_status = status_line_to;
-                    return path_cmd_move_to;
-                }
-                m_status = status_stop;
-                return path_cmd_end_poly | path_flags_close;
-            }
-        }
-        else
-        {
-            if(next_vertex(x, y))
-            {
-                return path_cmd_line_to;
-            }
-            else
-            {
-                m_status = status_move_to;
-            }
-            return path_cmd_end_poly | path_flags_close;
-        }
-        return path_cmd_stop;
-    }
-
-   
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_conv_marker.h b/xs/src/agg/agg_conv_marker.h
deleted file mode 100644
index 2cd3cb403..000000000
--- a/xs/src/agg/agg_conv_marker.h
+++ /dev/null
@@ -1,148 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// conv_marker
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_MARKER_INCLUDED
-#define AGG_CONV_MARKER_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_trans_affine.h"
-
-namespace agg
-{
-    //-------------------------------------------------------------conv_marker
-    template<class MarkerLocator, class MarkerShapes>
-    class conv_marker
-    {
-    public:
-        conv_marker(MarkerLocator& ml, MarkerShapes& ms);
-
-        trans_affine& transform() { return m_transform; }
-        const trans_affine& transform() const { return m_transform; }
-
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        conv_marker(const conv_marker<MarkerLocator, MarkerShapes>&);
-        const conv_marker<MarkerLocator, MarkerShapes>& 
-            operator = (const conv_marker<MarkerLocator, MarkerShapes>&);
-
-        enum status_e 
-        {
-            initial,
-            markers,
-            polygon,
-            stop
-        };
-
-        MarkerLocator* m_marker_locator;
-        MarkerShapes*  m_marker_shapes;
-        trans_affine   m_transform;
-        trans_affine   m_mtx;
-        status_e       m_status;
-        unsigned       m_marker;
-        unsigned       m_num_markers;
-    };
-
-
-    //------------------------------------------------------------------------
-    template<class MarkerLocator, class MarkerShapes> 
-    conv_marker<MarkerLocator, MarkerShapes>::conv_marker(MarkerLocator& ml, MarkerShapes& ms) :
-        m_marker_locator(&ml),
-        m_marker_shapes(&ms),
-        m_status(initial),
-        m_marker(0),
-        m_num_markers(1)
-    {
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class MarkerLocator, class MarkerShapes> 
-    void conv_marker<MarkerLocator, MarkerShapes>::rewind(unsigned)
-    {
-        m_status = initial;
-        m_marker = 0;
-        m_num_markers = 1;
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class MarkerLocator, class MarkerShapes> 
-    unsigned conv_marker<MarkerLocator, MarkerShapes>::vertex(double* x, double* y)
-    {
-        unsigned cmd = path_cmd_move_to;
-        double x1, y1, x2, y2;
-
-        while(!is_stop(cmd))
-        {
-            switch(m_status)
-            {
-            case initial:
-                if(m_num_markers == 0)
-                {
-                   cmd = path_cmd_stop;
-                   break;
-                }
-                m_marker_locator->rewind(m_marker);
-                ++m_marker;
-                m_num_markers = 0;
-                m_status = markers;
-
-            case markers:
-                if(is_stop(m_marker_locator->vertex(&x1, &y1)))
-                {
-                    m_status = initial;
-                    break;
-                }
-                if(is_stop(m_marker_locator->vertex(&x2, &y2)))
-                {
-                    m_status = initial;
-                    break;
-                }
-                ++m_num_markers;
-                m_mtx = m_transform;
-                m_mtx *= trans_affine_rotation(atan2(y2 - y1, x2 - x1));
-                m_mtx *= trans_affine_translation(x1, y1);
-                m_marker_shapes->rewind(m_marker - 1);
-                m_status = polygon;
-
-            case polygon:
-                cmd = m_marker_shapes->vertex(x, y);
-                if(is_stop(cmd))
-                {
-                    cmd = path_cmd_move_to;
-                    m_status = markers;
-                    break;
-                }
-                m_mtx.transform(x, y);
-                return cmd;
-
-            case stop:
-                cmd = path_cmd_stop;
-                break;
-            }
-        }
-        return cmd;
-    }
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_conv_marker_adaptor.h b/xs/src/agg/agg_conv_marker_adaptor.h
deleted file mode 100644
index 4486d6ace..000000000
--- a/xs/src/agg/agg_conv_marker_adaptor.h
+++ /dev/null
@@ -1,51 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_MARKER_ADAPTOR_INCLUDED
-#define AGG_CONV_MARKER_ADAPTOR_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_conv_adaptor_vcgen.h"
-#include "agg_vcgen_vertex_sequence.h"
-
-namespace agg
-{
-
-    //=====================================================conv_marker_adaptor
-    template<class VertexSource, class Markers=null_markers>
-    struct conv_marker_adaptor : 
-    public conv_adaptor_vcgen<VertexSource, vcgen_vertex_sequence, Markers>
-    {
-        typedef Markers marker_type;
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_vertex_sequence, Markers> base_type;
-
-        conv_marker_adaptor(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_vertex_sequence, Markers>(vs)
-        {
-        }
-
-        void shorten(double s) { base_type::generator().shorten(s); }
-        double shorten() const { return base_type::generator().shorten(); }
-
-    private:
-        conv_marker_adaptor(const conv_marker_adaptor<VertexSource, Markers>&);
-        const conv_marker_adaptor<VertexSource, Markers>& 
-            operator = (const conv_marker_adaptor<VertexSource, Markers>&);
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_segmentator.h b/xs/src/agg/agg_conv_segmentator.h
deleted file mode 100644
index e69a9e7d7..000000000
--- a/xs/src/agg/agg_conv_segmentator.h
+++ /dev/null
@@ -1,48 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_SEGMENTATOR_INCLUDED
-#define AGG_CONV_SEGMENTATOR_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_conv_adaptor_vpgen.h"
-#include "agg_vpgen_segmentator.h"
-
-namespace agg
-{
-
-    //========================================================conv_segmentator
-    template<class VertexSource> 
-    struct conv_segmentator : public conv_adaptor_vpgen<VertexSource, vpgen_segmentator>
-    {
-        typedef conv_adaptor_vpgen<VertexSource, vpgen_segmentator> base_type;
-
-        conv_segmentator(VertexSource& vs) : 
-            conv_adaptor_vpgen<VertexSource, vpgen_segmentator>(vs) {}
-
-        void approximation_scale(double s) { base_type::vpgen().approximation_scale(s);        }
-        double approximation_scale() const { return base_type::vpgen().approximation_scale();  }
-
-    private:
-        conv_segmentator(const conv_segmentator<VertexSource>&);
-        const conv_segmentator<VertexSource>& 
-            operator = (const conv_segmentator<VertexSource>&);
-    };
-
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_conv_shorten_path.h b/xs/src/agg/agg_conv_shorten_path.h
deleted file mode 100644
index 5617e51d1..000000000
--- a/xs/src/agg/agg_conv_shorten_path.h
+++ /dev/null
@@ -1,50 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_SHORTEN_PATH_INCLUDED
-#define AGG_CONV_SHORTEN_PATH_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_conv_adaptor_vcgen.h"
-#include "agg_vcgen_vertex_sequence.h"
-
-namespace agg
-{
-
-    //=======================================================conv_shorten_path
-    template<class VertexSource>  class conv_shorten_path : 
-    public conv_adaptor_vcgen<VertexSource, vcgen_vertex_sequence>
-    {
-    public:
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_vertex_sequence> base_type;
-
-        conv_shorten_path(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_vertex_sequence>(vs)
-        {
-        }
-
-        void shorten(double s) { base_type::generator().shorten(s); }
-        double shorten() const { return base_type::generator().shorten(); }
-
-    private:
-        conv_shorten_path(const conv_shorten_path<VertexSource>&);
-        const conv_shorten_path<VertexSource>& 
-            operator = (const conv_shorten_path<VertexSource>&);
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_smooth_poly1.h b/xs/src/agg/agg_conv_smooth_poly1.h
deleted file mode 100644
index 4ac4e3d6e..000000000
--- a/xs/src/agg/agg_conv_smooth_poly1.h
+++ /dev/null
@@ -1,80 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Smooth polygon generator
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_SMOOTH_POLY1_INCLUDED
-#define AGG_CONV_SMOOTH_POLY1_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vcgen_smooth_poly1.h"
-#include "agg_conv_adaptor_vcgen.h"
-#include "agg_conv_curve.h"
-
-
-namespace agg
-{
-
-    //-------------------------------------------------------conv_smooth_poly1
-    template<class VertexSource> 
-    struct conv_smooth_poly1 : 
-    public conv_adaptor_vcgen<VertexSource, vcgen_smooth_poly1>
-    {
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_smooth_poly1> base_type;
-
-        conv_smooth_poly1(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_smooth_poly1>(vs)
-        {
-        }
-
-        void   smooth_value(double v) { base_type::generator().smooth_value(v); }
-        double smooth_value() const { return base_type::generator().smooth_value(); }
-
-    private:
-        conv_smooth_poly1(const conv_smooth_poly1<VertexSource>&);
-        const conv_smooth_poly1<VertexSource>& 
-            operator = (const conv_smooth_poly1<VertexSource>&);
-    };
-
-
-
-    //-------------------------------------------------conv_smooth_poly1_curve
-    template<class VertexSource> 
-    struct conv_smooth_poly1_curve : 
-    public conv_curve<conv_smooth_poly1<VertexSource> >
-    {
-        conv_smooth_poly1_curve(VertexSource& vs) :
-            conv_curve<conv_smooth_poly1<VertexSource> >(m_smooth),
-            m_smooth(vs)
-        {
-        }
-
-        void   smooth_value(double v) { m_smooth.generator().smooth_value(v); }
-        double smooth_value() const { return m_smooth.generator().smooth_value(); }
-
-    private:
-        conv_smooth_poly1_curve(const conv_smooth_poly1_curve<VertexSource>&);
-        const conv_smooth_poly1_curve<VertexSource>& 
-            operator = (const conv_smooth_poly1_curve<VertexSource>&);
-
-        conv_smooth_poly1<VertexSource> m_smooth;
-    };
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_conv_stroke.h b/xs/src/agg/agg_conv_stroke.h
deleted file mode 100644
index e19a6b61f..000000000
--- a/xs/src/agg/agg_conv_stroke.h
+++ /dev/null
@@ -1,73 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// conv_stroke
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_CONV_STROKE_INCLUDED
-#define AGG_CONV_STROKE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vcgen_stroke.h"
-#include "agg_conv_adaptor_vcgen.h"
-
-namespace agg
-{
-
-    //-------------------------------------------------------------conv_stroke
-    template<class VertexSource, class Markers=null_markers> 
-    struct conv_stroke : 
-    public conv_adaptor_vcgen<VertexSource, vcgen_stroke, Markers>
-    {
-        typedef Markers marker_type;
-        typedef conv_adaptor_vcgen<VertexSource, vcgen_stroke, Markers> base_type;
-
-        conv_stroke(VertexSource& vs) : 
-            conv_adaptor_vcgen<VertexSource, vcgen_stroke, Markers>(vs)
-        {
-        }
-
-        void line_cap(line_cap_e lc)     { base_type::generator().line_cap(lc);  }
-        void line_join(line_join_e lj)   { base_type::generator().line_join(lj); }
-        void inner_join(inner_join_e ij) { base_type::generator().inner_join(ij); }
-
-        line_cap_e   line_cap()   const { return base_type::generator().line_cap();  }
-        line_join_e  line_join()  const { return base_type::generator().line_join(); }
-        inner_join_e inner_join() const { return base_type::generator().inner_join(); }
-
-        void width(double w) { base_type::generator().width(w); }
-        void miter_limit(double ml) { base_type::generator().miter_limit(ml); }
-        void miter_limit_theta(double t) { base_type::generator().miter_limit_theta(t); }
-        void inner_miter_limit(double ml) { base_type::generator().inner_miter_limit(ml); }
-        void approximation_scale(double as) { base_type::generator().approximation_scale(as); }
-
-        double width() const { return base_type::generator().width(); }
-        double miter_limit() const { return base_type::generator().miter_limit(); }
-        double inner_miter_limit() const { return base_type::generator().inner_miter_limit(); }
-        double approximation_scale() const { return base_type::generator().approximation_scale(); }
-
-        void shorten(double s) { base_type::generator().shorten(s); }
-        double shorten() const { return base_type::generator().shorten(); }
-
-    private:
-       conv_stroke(const conv_stroke<VertexSource, Markers>&);
-       const conv_stroke<VertexSource, Markers>& 
-           operator = (const conv_stroke<VertexSource, Markers>&);
-
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_conv_unclose_polygon.h b/xs/src/agg/agg_conv_unclose_polygon.h
deleted file mode 100644
index fe5c26381..000000000
--- a/xs/src/agg/agg_conv_unclose_polygon.h
+++ /dev/null
@@ -1,52 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CONV_UNCLOSE_POLYGON_INCLUDED
-#define AGG_CONV_UNCLOSE_POLYGON_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //====================================================conv_unclose_polygon
-    template<class VertexSource> class conv_unclose_polygon
-    {
-    public:
-        explicit conv_unclose_polygon(VertexSource& vs) : m_source(&vs) {}
-        void attach(VertexSource& source) { m_source = &source; }
-
-        void rewind(unsigned path_id)
-        {
-            m_source->rewind(path_id);
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            unsigned cmd = m_source->vertex(x, y);
-            if(is_end_poly(cmd)) cmd &= ~path_flags_close;
-            return cmd;
-        }
-
-    private:
-        conv_unclose_polygon(const conv_unclose_polygon<VertexSource>&);
-        const conv_unclose_polygon<VertexSource>& 
-            operator = (const conv_unclose_polygon<VertexSource>&);
-
-        VertexSource* m_source;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_curves.h b/xs/src/agg/agg_curves.h
deleted file mode 100644
index 1ef02e878..000000000
--- a/xs/src/agg/agg_curves.h
+++ /dev/null
@@ -1,693 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-// Copyright (C) 2005 Tony Juricic (tonygeek@yahoo.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_CURVES_INCLUDED
-#define AGG_CURVES_INCLUDED
-
-#include "agg_array.h"
-
-namespace agg
-{
-
-    // See Implementation agg_curves.cpp
-
-    //--------------------------------------------curve_approximation_method_e
-    enum curve_approximation_method_e
-    {
-        curve_inc,
-        curve_div
-    };
-    
-    //--------------------------------------------------------------curve3_inc
-    class curve3_inc
-    {
-    public:
-        curve3_inc() :
-          m_num_steps(0), m_step(0), m_scale(1.0) { }
-
-        curve3_inc(double x1, double y1, 
-                   double x2, double y2, 
-                   double x3, double y3) :
-            m_num_steps(0), m_step(0), m_scale(1.0) 
-        { 
-            init(x1, y1, x2, y2, x3, y3);
-        }
-
-        void reset() { m_num_steps = 0; m_step = -1; }
-        void init(double x1, double y1, 
-                  double x2, double y2, 
-                  double x3, double y3);
-
-        void approximation_method(curve_approximation_method_e) {}
-        curve_approximation_method_e approximation_method() const { return curve_inc; }
-
-        void approximation_scale(double s);
-        double approximation_scale() const;
-
-        void angle_tolerance(double) {}
-        double angle_tolerance() const { return 0.0; }
-
-        void cusp_limit(double) {}
-        double cusp_limit() const { return 0.0; }
-
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        int      m_num_steps;
-        int      m_step;
-        double   m_scale;
-        double   m_start_x; 
-        double   m_start_y;
-        double   m_end_x; 
-        double   m_end_y;
-        double   m_fx; 
-        double   m_fy;
-        double   m_dfx; 
-        double   m_dfy;
-        double   m_ddfx; 
-        double   m_ddfy;
-        double   m_saved_fx; 
-        double   m_saved_fy;
-        double   m_saved_dfx; 
-        double   m_saved_dfy;
-    };
-
-
-
-
-
-    //-------------------------------------------------------------curve3_div
-    class curve3_div
-    {
-    public:
-        curve3_div() : 
-            m_approximation_scale(1.0),
-            m_angle_tolerance(0.0),
-            m_count(0)
-        {}
-
-        curve3_div(double x1, double y1, 
-                   double x2, double y2, 
-                   double x3, double y3) :
-            m_approximation_scale(1.0),
-            m_angle_tolerance(0.0),
-            m_count(0)
-        { 
-            init(x1, y1, x2, y2, x3, y3);
-        }
-
-        void reset() { m_points.remove_all(); m_count = 0; }
-        void init(double x1, double y1, 
-                  double x2, double y2, 
-                  double x3, double y3);
-
-        void approximation_method(curve_approximation_method_e) {}
-        curve_approximation_method_e approximation_method() const { return curve_div; }
-
-        void approximation_scale(double s) { m_approximation_scale = s; }
-        double approximation_scale() const { return m_approximation_scale;  }
-
-        void angle_tolerance(double a) { m_angle_tolerance = a; }
-        double angle_tolerance() const { return m_angle_tolerance;  }
-
-        void cusp_limit(double) {}
-        double cusp_limit() const { return 0.0; }
-
-        void rewind(unsigned)
-        {
-            m_count = 0;
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            if(m_count >= m_points.size()) return path_cmd_stop;
-            const point_d& p = m_points[m_count++];
-            *x = p.x;
-            *y = p.y;
-            return (m_count == 1) ? path_cmd_move_to : path_cmd_line_to;
-        }
-
-    private:
-        void bezier(double x1, double y1, 
-                    double x2, double y2, 
-                    double x3, double y3);
-        void recursive_bezier(double x1, double y1, 
-                              double x2, double y2, 
-                              double x3, double y3,
-                              unsigned level);
-
-        double               m_approximation_scale;
-        double               m_distance_tolerance_square;
-        double               m_angle_tolerance;
-        unsigned             m_count;
-        pod_bvector<point_d> m_points;
-    };
-
-
-
-
-
-
-
-    //-------------------------------------------------------------curve4_points
-    struct curve4_points
-    {
-        double cp[8];
-        curve4_points() {}
-        curve4_points(double x1, double y1,
-                      double x2, double y2,
-                      double x3, double y3,
-                      double x4, double y4)
-        {
-            cp[0] = x1; cp[1] = y1; cp[2] = x2; cp[3] = y2;
-            cp[4] = x3; cp[5] = y3; cp[6] = x4; cp[7] = y4;
-        }
-        void init(double x1, double y1,
-                  double x2, double y2,
-                  double x3, double y3,
-                  double x4, double y4)
-        {
-            cp[0] = x1; cp[1] = y1; cp[2] = x2; cp[3] = y2;
-            cp[4] = x3; cp[5] = y3; cp[6] = x4; cp[7] = y4;
-        }
-        double  operator [] (unsigned i) const { return cp[i]; }
-        double& operator [] (unsigned i)       { return cp[i]; }
-    };
-
-
-
-    //-------------------------------------------------------------curve4_inc
-    class curve4_inc
-    {
-    public:
-        curve4_inc() :
-            m_num_steps(0), m_step(0), m_scale(1.0) { }
-
-        curve4_inc(double x1, double y1, 
-                   double x2, double y2, 
-                   double x3, double y3,
-                   double x4, double y4) :
-            m_num_steps(0), m_step(0), m_scale(1.0) 
-        { 
-            init(x1, y1, x2, y2, x3, y3, x4, y4);
-        }
-
-        curve4_inc(const curve4_points& cp) :
-            m_num_steps(0), m_step(0), m_scale(1.0) 
-        { 
-            init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
-        }
-
-        void reset() { m_num_steps = 0; m_step = -1; }
-        void init(double x1, double y1, 
-                  double x2, double y2, 
-                  double x3, double y3,
-                  double x4, double y4);
-
-        void init(const curve4_points& cp)
-        {
-            init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
-        }
-
-        void approximation_method(curve_approximation_method_e) {}
-        curve_approximation_method_e approximation_method() const { return curve_inc; }
-
-        void approximation_scale(double s);
-        double approximation_scale() const;
-
-        void angle_tolerance(double) {}
-        double angle_tolerance() const { return 0.0; }
-
-        void cusp_limit(double) {}
-        double cusp_limit() const { return 0.0; }
-
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        int      m_num_steps;
-        int      m_step;
-        double   m_scale;
-        double   m_start_x; 
-        double   m_start_y;
-        double   m_end_x; 
-        double   m_end_y;
-        double   m_fx; 
-        double   m_fy;
-        double   m_dfx; 
-        double   m_dfy;
-        double   m_ddfx; 
-        double   m_ddfy;
-        double   m_dddfx; 
-        double   m_dddfy;
-        double   m_saved_fx; 
-        double   m_saved_fy;
-        double   m_saved_dfx; 
-        double   m_saved_dfy;
-        double   m_saved_ddfx; 
-        double   m_saved_ddfy;
-    };
-
-
-
-    //-------------------------------------------------------catrom_to_bezier
-    inline curve4_points catrom_to_bezier(double x1, double y1, 
-                                          double x2, double y2, 
-                                          double x3, double y3,
-                                          double x4, double y4)
-    {
-        // Trans. matrix Catmull-Rom to Bezier
-        //
-        //  0       1       0       0
-        //  -1/6    1       1/6     0
-        //  0       1/6     1       -1/6
-        //  0       0       1       0
-        //
-        return curve4_points(
-            x2,
-            y2,
-            (-x1 + 6*x2 + x3) / 6,
-            (-y1 + 6*y2 + y3) / 6,
-            ( x2 + 6*x3 - x4) / 6,
-            ( y2 + 6*y3 - y4) / 6,
-            x3,
-            y3);
-    }
-
-
-    //-----------------------------------------------------------------------
-    inline curve4_points
-    catrom_to_bezier(const curve4_points& cp)
-    {
-        return catrom_to_bezier(cp[0], cp[1], cp[2], cp[3], 
-                                cp[4], cp[5], cp[6], cp[7]);
-    }
-
-
-
-    //-----------------------------------------------------ubspline_to_bezier
-    inline curve4_points ubspline_to_bezier(double x1, double y1, 
-                                            double x2, double y2, 
-                                            double x3, double y3,
-                                            double x4, double y4)
-    {
-        // Trans. matrix Uniform BSpline to Bezier
-        //
-        //  1/6     4/6     1/6     0
-        //  0       4/6     2/6     0
-        //  0       2/6     4/6     0
-        //  0       1/6     4/6     1/6
-        //
-        return curve4_points(
-            (x1 + 4*x2 + x3) / 6,
-            (y1 + 4*y2 + y3) / 6,
-            (4*x2 + 2*x3) / 6,
-            (4*y2 + 2*y3) / 6,
-            (2*x2 + 4*x3) / 6,
-            (2*y2 + 4*y3) / 6,
-            (x2 + 4*x3 + x4) / 6,
-            (y2 + 4*y3 + y4) / 6);
-    }
-
-
-    //-----------------------------------------------------------------------
-    inline curve4_points 
-    ubspline_to_bezier(const curve4_points& cp)
-    {
-        return ubspline_to_bezier(cp[0], cp[1], cp[2], cp[3], 
-                                  cp[4], cp[5], cp[6], cp[7]);
-    }
-
-
-
-
-    //------------------------------------------------------hermite_to_bezier
-    inline curve4_points hermite_to_bezier(double x1, double y1, 
-                                           double x2, double y2, 
-                                           double x3, double y3,
-                                           double x4, double y4)
-    {
-        // Trans. matrix Hermite to Bezier
-        //
-        //  1       0       0       0
-        //  1       0       1/3     0
-        //  0       1       0       -1/3
-        //  0       1       0       0
-        //
-        return curve4_points(
-            x1,
-            y1,
-            (3*x1 + x3) / 3,
-            (3*y1 + y3) / 3,
-            (3*x2 - x4) / 3,
-            (3*y2 - y4) / 3,
-            x2,
-            y2);
-    }
-
-
-
-    //-----------------------------------------------------------------------
-    inline curve4_points 
-    hermite_to_bezier(const curve4_points& cp)
-    {
-        return hermite_to_bezier(cp[0], cp[1], cp[2], cp[3], 
-                                 cp[4], cp[5], cp[6], cp[7]);
-    }
-
-
-    //-------------------------------------------------------------curve4_div
-    class curve4_div
-    {
-    public:
-        curve4_div() : 
-            m_approximation_scale(1.0),
-            m_angle_tolerance(0.0),
-            m_cusp_limit(0.0),
-            m_count(0)
-        {}
-
-        curve4_div(double x1, double y1, 
-                   double x2, double y2, 
-                   double x3, double y3,
-                   double x4, double y4) :
-            m_approximation_scale(1.0),
-            m_angle_tolerance(0.0),
-            m_cusp_limit(0.0),
-            m_count(0)
-        { 
-            init(x1, y1, x2, y2, x3, y3, x4, y4);
-        }
-
-        curve4_div(const curve4_points& cp) :
-            m_approximation_scale(1.0),
-            m_angle_tolerance(0.0),
-            m_count(0)
-        { 
-            init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
-        }
-
-        void reset() { m_points.remove_all(); m_count = 0; }
-        void init(double x1, double y1, 
-                  double x2, double y2, 
-                  double x3, double y3,
-                  double x4, double y4);
-
-        void init(const curve4_points& cp)
-        {
-            init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
-        }
-
-        void approximation_method(curve_approximation_method_e) {}
-
-        curve_approximation_method_e approximation_method() const 
-        { 
-            return curve_div; 
-        }
-
-        void approximation_scale(double s) { m_approximation_scale = s; }
-        double approximation_scale() const { return m_approximation_scale;  }
-
-        void angle_tolerance(double a) { m_angle_tolerance = a; }
-        double angle_tolerance() const { return m_angle_tolerance;  }
-
-        void cusp_limit(double v) 
-        { 
-            m_cusp_limit = (v == 0.0) ? 0.0 : pi - v; 
-        }
-
-        double cusp_limit() const 
-        { 
-            return (m_cusp_limit == 0.0) ? 0.0 : pi - m_cusp_limit; 
-        }
-
-        void rewind(unsigned)
-        {
-            m_count = 0;
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            if(m_count >= m_points.size()) return path_cmd_stop;
-            const point_d& p = m_points[m_count++];
-            *x = p.x;
-            *y = p.y;
-            return (m_count == 1) ? path_cmd_move_to : path_cmd_line_to;
-        }
-
-    private:
-        void bezier(double x1, double y1, 
-                    double x2, double y2, 
-                    double x3, double y3, 
-                    double x4, double y4);
-
-        void recursive_bezier(double x1, double y1, 
-                              double x2, double y2, 
-                              double x3, double y3, 
-                              double x4, double y4,
-                              unsigned level);
-
-        double               m_approximation_scale;
-        double               m_distance_tolerance_square;
-        double               m_angle_tolerance;
-        double               m_cusp_limit;
-        unsigned             m_count;
-        pod_bvector<point_d> m_points;
-    };
-
-
-    //-----------------------------------------------------------------curve3
-    class curve3
-    {
-    public:
-        curve3() : m_approximation_method(curve_div) {}
-        curve3(double x1, double y1, 
-               double x2, double y2, 
-               double x3, double y3) :
-            m_approximation_method(curve_div)
-        { 
-            init(x1, y1, x2, y2, x3, y3);
-        }
-
-        void reset() 
-        { 
-            m_curve_inc.reset();
-            m_curve_div.reset();
-        }
-
-        void init(double x1, double y1, 
-                  double x2, double y2, 
-                  double x3, double y3)
-        {
-            if(m_approximation_method == curve_inc) 
-            {
-                m_curve_inc.init(x1, y1, x2, y2, x3, y3);
-            }
-            else
-            {
-                m_curve_div.init(x1, y1, x2, y2, x3, y3);
-            }
-        }
-
-        void approximation_method(curve_approximation_method_e v) 
-        { 
-            m_approximation_method = v; 
-        }
-
-        curve_approximation_method_e approximation_method() const 
-        { 
-            return m_approximation_method; 
-        }
-
-        void approximation_scale(double s) 
-        { 
-            m_curve_inc.approximation_scale(s);
-            m_curve_div.approximation_scale(s);
-        }
-
-        double approximation_scale() const 
-        { 
-            return m_curve_inc.approximation_scale(); 
-        }
-
-        void angle_tolerance(double a) 
-        { 
-            m_curve_div.angle_tolerance(a); 
-        }
-
-        double angle_tolerance() const 
-        { 
-            return m_curve_div.angle_tolerance(); 
-        }
-
-        void cusp_limit(double v) 
-        { 
-            m_curve_div.cusp_limit(v); 
-        }
-
-        double cusp_limit() const 
-        { 
-            return m_curve_div.cusp_limit();  
-        }
-
-        void rewind(unsigned path_id)
-        {
-            if(m_approximation_method == curve_inc) 
-            {
-                m_curve_inc.rewind(path_id);
-            }
-            else
-            {
-                m_curve_div.rewind(path_id);
-            }
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            if(m_approximation_method == curve_inc) 
-            {
-                return m_curve_inc.vertex(x, y);
-            }
-            return m_curve_div.vertex(x, y);
-        }
-
-    private:
-        curve3_inc m_curve_inc;
-        curve3_div m_curve_div;
-        curve_approximation_method_e m_approximation_method;
-    };
-
-
-
-
-
-    //-----------------------------------------------------------------curve4
-    class curve4
-    {
-    public:
-        curve4() : m_approximation_method(curve_div) {}
-        curve4(double x1, double y1, 
-               double x2, double y2, 
-               double x3, double y3,
-               double x4, double y4) : 
-            m_approximation_method(curve_div)
-        { 
-            init(x1, y1, x2, y2, x3, y3, x4, y4);
-        }
-
-        curve4(const curve4_points& cp) :
-            m_approximation_method(curve_div)
-        { 
-            init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
-        }
-
-        void reset() 
-        { 
-            m_curve_inc.reset();
-            m_curve_div.reset();
-        }
-
-        void init(double x1, double y1, 
-                  double x2, double y2, 
-                  double x3, double y3,
-                  double x4, double y4)
-        {
-            if(m_approximation_method == curve_inc) 
-            {
-                m_curve_inc.init(x1, y1, x2, y2, x3, y3, x4, y4);
-            }
-            else
-            {
-                m_curve_div.init(x1, y1, x2, y2, x3, y3, x4, y4);
-            }
-        }
-
-        void init(const curve4_points& cp)
-        {
-            init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
-        }
-
-        void approximation_method(curve_approximation_method_e v) 
-        { 
-            m_approximation_method = v; 
-        }
-
-        curve_approximation_method_e approximation_method() const 
-        { 
-            return m_approximation_method; 
-        }
-
-        void approximation_scale(double s) 
-        { 
-            m_curve_inc.approximation_scale(s);
-            m_curve_div.approximation_scale(s);
-        }
-        double approximation_scale() const { return m_curve_inc.approximation_scale(); }
-
-        void angle_tolerance(double v) 
-        { 
-            m_curve_div.angle_tolerance(v); 
-        }
-
-        double angle_tolerance() const 
-        { 
-            return m_curve_div.angle_tolerance();  
-        }
-
-        void cusp_limit(double v) 
-        { 
-            m_curve_div.cusp_limit(v); 
-        }
-
-        double cusp_limit() const 
-        { 
-            return m_curve_div.cusp_limit();  
-        }
-
-        void rewind(unsigned path_id)
-        {
-            if(m_approximation_method == curve_inc) 
-            {
-                m_curve_inc.rewind(path_id);
-            }
-            else
-            {
-                m_curve_div.rewind(path_id);
-            }
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            if(m_approximation_method == curve_inc) 
-            {
-                return m_curve_inc.vertex(x, y);
-            }
-            return m_curve_div.vertex(x, y);
-        }
-
-    private:
-        curve4_inc m_curve_inc;
-        curve4_div m_curve_div;
-        curve_approximation_method_e m_approximation_method;
-    };
-
-
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_dda_line.h b/xs/src/agg/agg_dda_line.h
deleted file mode 100644
index f589e76b8..000000000
--- a/xs/src/agg/agg_dda_line.h
+++ /dev/null
@@ -1,290 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// classes dda_line_interpolator, dda2_line_interpolator
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_DDA_LINE_INCLUDED
-#define AGG_DDA_LINE_INCLUDED
-
-#include <stdlib.h>
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //===================================================dda_line_interpolator
-    template<int FractionShift, int YShift=0> class dda_line_interpolator
-    {
-    public:
-        //--------------------------------------------------------------------
-        dda_line_interpolator() {}
-
-        //--------------------------------------------------------------------
-        dda_line_interpolator(int y1, int y2, unsigned count) :
-            m_y(y1),
-            m_inc(((y2 - y1) << FractionShift) / int(count)),
-            m_dy(0)
-        {
-        }
-
-        //--------------------------------------------------------------------
-        void operator ++ ()
-        {
-            m_dy += m_inc;
-        }
-
-        //--------------------------------------------------------------------
-        void operator -- ()
-        {
-            m_dy -= m_inc;
-        }
-
-        //--------------------------------------------------------------------
-        void operator += (unsigned n)
-        {
-            m_dy += m_inc * n;
-        }
-
-        //--------------------------------------------------------------------
-        void operator -= (unsigned n)
-        {
-            m_dy -= m_inc * n;
-        }
-
-
-        //--------------------------------------------------------------------
-        int y()  const { return m_y + (m_dy >> (FractionShift-YShift)); }
-        int dy() const { return m_dy; }
-
-
-    private:
-        int m_y;
-        int m_inc;
-        int m_dy;
-    };
-
-
-
-
-
-    //=================================================dda2_line_interpolator
-    class dda2_line_interpolator
-    {
-    public:
-        typedef int save_data_type;
-        enum save_size_e { save_size = 2 };
-
-        //--------------------------------------------------------------------
-        dda2_line_interpolator() {}
-
-        //-------------------------------------------- Forward-adjusted line
-        dda2_line_interpolator(int y1, int y2, int count) :
-            m_cnt(count <= 0 ? 1 : count),
-            m_lft((y2 - y1) / m_cnt),
-            m_rem((y2 - y1) % m_cnt),
-            m_mod(m_rem),
-            m_y(y1)
-        {
-            if(m_mod <= 0)
-            {
-                m_mod += count;
-                m_rem += count;
-                m_lft--;
-            }
-            m_mod -= count;
-        }
-
-        //-------------------------------------------- Backward-adjusted line
-        dda2_line_interpolator(int y1, int y2, int count, int) :
-            m_cnt(count <= 0 ? 1 : count),
-            m_lft((y2 - y1) / m_cnt),
-            m_rem((y2 - y1) % m_cnt),
-            m_mod(m_rem),
-            m_y(y1)
-        {
-            if(m_mod <= 0)
-            {
-                m_mod += count;
-                m_rem += count;
-                m_lft--;
-            }
-        }
-
-        //-------------------------------------------- Backward-adjusted line
-        dda2_line_interpolator(int y, int count) :
-            m_cnt(count <= 0 ? 1 : count),
-            m_lft(y / m_cnt),
-            m_rem(y % m_cnt),
-            m_mod(m_rem),
-            m_y(0)
-        {
-            if(m_mod <= 0)
-            {
-                m_mod += count;
-                m_rem += count;
-                m_lft--;
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void save(save_data_type* data) const
-        {
-            data[0] = m_mod;
-            data[1] = m_y;
-        }
-
-        //--------------------------------------------------------------------
-        void load(const save_data_type* data)
-        {
-            m_mod = data[0];
-            m_y   = data[1];
-        }
-
-        //--------------------------------------------------------------------
-        void operator++()
-        {
-            m_mod += m_rem;
-            m_y += m_lft;
-            if(m_mod > 0)
-            {
-                m_mod -= m_cnt;
-                m_y++;
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void operator--()
-        {
-            if(m_mod <= m_rem)
-            {
-                m_mod += m_cnt;
-                m_y--;
-            }
-            m_mod -= m_rem;
-            m_y -= m_lft;
-        }
-
-        //--------------------------------------------------------------------
-        void adjust_forward()
-        {
-            m_mod -= m_cnt;
-        }
-
-        //--------------------------------------------------------------------
-        void adjust_backward()
-        {
-            m_mod += m_cnt;
-        }
-
-        //--------------------------------------------------------------------
-        int mod() const { return m_mod; }
-        int rem() const { return m_rem; }
-        int lft() const { return m_lft; }
-
-        //--------------------------------------------------------------------
-        int y() const { return m_y; }
-
-    private:
-        int m_cnt;
-        int m_lft;
-        int m_rem;
-        int m_mod;
-        int m_y;
-    };
-
-
-
-
-
-
-
-    //---------------------------------------------line_bresenham_interpolator
-    class line_bresenham_interpolator
-    {
-    public:
-        enum subpixel_scale_e
-        {
-            subpixel_shift = 8,
-            subpixel_scale = 1 << subpixel_shift,
-            subpixel_mask  = subpixel_scale - 1
-        };
-
-        //--------------------------------------------------------------------
-        static int line_lr(int v) { return v >> subpixel_shift; }
-
-        //--------------------------------------------------------------------
-        line_bresenham_interpolator(int x1, int y1, int x2, int y2) :
-            m_x1_lr(line_lr(x1)),
-            m_y1_lr(line_lr(y1)),
-            m_x2_lr(line_lr(x2)),
-            m_y2_lr(line_lr(y2)),
-            m_ver(abs(m_x2_lr - m_x1_lr) < abs(m_y2_lr - m_y1_lr)),
-            m_len(m_ver ? abs(m_y2_lr - m_y1_lr) : 
-                          abs(m_x2_lr - m_x1_lr)),
-            m_inc(m_ver ? ((y2 > y1) ? 1 : -1) : ((x2 > x1) ? 1 : -1)),
-            m_interpolator(m_ver ? x1 : y1, 
-                           m_ver ? x2 : y2, 
-                           m_len)
-        {
-        }
-    
-        //--------------------------------------------------------------------
-        bool     is_ver() const { return m_ver; }
-        unsigned len()    const { return m_len; }
-        int      inc()    const { return m_inc; }
-
-        //--------------------------------------------------------------------
-        void hstep()
-        {
-            ++m_interpolator;
-            m_x1_lr += m_inc;
-        }
-
-        //--------------------------------------------------------------------
-        void vstep()
-        {
-            ++m_interpolator;
-            m_y1_lr += m_inc;
-        }
-
-        //--------------------------------------------------------------------
-        int x1() const { return m_x1_lr; }
-        int y1() const { return m_y1_lr; }
-        int x2() const { return line_lr(m_interpolator.y()); }
-        int y2() const { return line_lr(m_interpolator.y()); }
-        int x2_hr() const { return m_interpolator.y(); }
-        int y2_hr() const { return m_interpolator.y(); }
-
-    private:
-        int                    m_x1_lr;
-        int                    m_y1_lr;
-        int                    m_x2_lr;
-        int                    m_y2_lr;
-        bool                   m_ver;
-        unsigned               m_len;
-        int                    m_inc;
-        dda2_line_interpolator m_interpolator;
-
-    };
-
-
-}
-
-
-
-#endif
diff --git a/xs/src/agg/agg_ellipse.h b/xs/src/agg/agg_ellipse.h
deleted file mode 100644
index e78ce27dd..000000000
--- a/xs/src/agg/agg_ellipse.h
+++ /dev/null
@@ -1,123 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// class ellipse
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_ELLIPSE_INCLUDED
-#define AGG_ELLIPSE_INCLUDED
-
-#include "agg_basics.h"
-#include <math.h>
-
-namespace agg
-{
-
-    //----------------------------------------------------------------ellipse
-    class ellipse
-    {
-    public:
-        ellipse() : 
-            m_x(0.0), m_y(0.0), m_rx(1.0), m_ry(1.0), m_scale(1.0), 
-            m_num(4), m_step(0), m_cw(false) {}
-
-        ellipse(double x, double y, double rx, double ry, 
-                unsigned num_steps=0, bool cw=false) :
-            m_x(x), m_y(y), m_rx(rx), m_ry(ry), m_scale(1.0), 
-            m_num(num_steps), m_step(0), m_cw(cw) 
-        {
-            if(m_num == 0) calc_num_steps();
-        }
-
-        void init(double x, double y, double rx, double ry, 
-                  unsigned num_steps=0, bool cw=false);
-
-        void approximation_scale(double scale);
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        void calc_num_steps();
-
-        double m_x;
-        double m_y;
-        double m_rx;
-        double m_ry;
-        double m_scale;
-        unsigned m_num;
-        unsigned m_step;
-        bool m_cw;
-    };
-
-    //------------------------------------------------------------------------
-    inline void ellipse::init(double x, double y, double rx, double ry, 
-                              unsigned num_steps, bool cw)
-    {
-        m_x = x;
-        m_y = y;
-        m_rx = rx;
-        m_ry = ry;
-        m_num = num_steps;
-        m_step = 0;
-        m_cw = cw;
-        if(m_num == 0) calc_num_steps();
-    }
-
-    //------------------------------------------------------------------------
-    inline void ellipse::approximation_scale(double scale)
-    {   
-        m_scale = scale;
-        calc_num_steps();
-    }
-
-    //------------------------------------------------------------------------
-    inline void ellipse::calc_num_steps()
-    {
-        double ra = (fabs(m_rx) + fabs(m_ry)) / 2;
-        double da = acos(ra / (ra + 0.125 / m_scale)) * 2;
-        m_num = uround(2*pi / da);
-    }
-
-    //------------------------------------------------------------------------
-    inline void ellipse::rewind(unsigned)
-    {
-        m_step = 0;
-    }
-
-    //------------------------------------------------------------------------
-    inline unsigned ellipse::vertex(double* x, double* y)
-    {
-        if(m_step == m_num) 
-        {
-            ++m_step;
-            return path_cmd_end_poly | path_flags_close | path_flags_ccw;
-        }
-        if(m_step > m_num) return path_cmd_stop;
-        double angle = double(m_step) / double(m_num) * 2.0 * pi;
-        if(m_cw) angle = 2.0 * pi - angle;
-        *x = m_x + cos(angle) * m_rx;
-        *y = m_y + sin(angle) * m_ry;
-        m_step++;
-        return ((m_step == 1) ? path_cmd_move_to : path_cmd_line_to);
-    }
-
-}
-
-
-
-#endif
-
-
diff --git a/xs/src/agg/agg_ellipse_bresenham.h b/xs/src/agg/agg_ellipse_bresenham.h
deleted file mode 100644
index ee3b9c463..000000000
--- a/xs/src/agg/agg_ellipse_bresenham.h
+++ /dev/null
@@ -1,113 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Simple Bresenham interpolator for ellipsees
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_ELLIPSE_BRESENHAM_INCLUDED
-#define AGG_ELLIPSE_BRESENHAM_INCLUDED
-
-
-#include "agg_basics.h"
-
-
-namespace agg
-{
-
-    //------------------------------------------ellipse_bresenham_interpolator
-    class ellipse_bresenham_interpolator
-    {
-    public:
-        ellipse_bresenham_interpolator(int rx, int ry) :
-            m_rx2(rx * rx),
-            m_ry2(ry * ry),
-            m_two_rx2(m_rx2 << 1),
-            m_two_ry2(m_ry2 << 1),
-            m_dx(0),
-            m_dy(0),
-            m_inc_x(0),
-            m_inc_y(-ry * m_two_rx2),
-            m_cur_f(0)
-        {}
-        
-        int dx() const { return m_dx; }
-        int dy() const { return m_dy; }
-
-        void operator++ ()
-        {
-            int  mx, my, mxy, min_m;
-            int  fx, fy, fxy;
-
-            mx = fx = m_cur_f + m_inc_x + m_ry2;
-            if(mx < 0) mx = -mx;
-
-            my = fy = m_cur_f + m_inc_y + m_rx2;
-            if(my < 0) my = -my;
-
-            mxy = fxy = m_cur_f + m_inc_x + m_ry2 + m_inc_y + m_rx2;
-            if(mxy < 0) mxy = -mxy;
-
-            min_m = mx; 
-            bool flag = true;
-
-            if(min_m > my)  
-            { 
-                min_m = my; 
-                flag = false; 
-            }
-
-            m_dx = m_dy = 0;
-
-            if(min_m > mxy) 
-            { 
-                m_inc_x += m_two_ry2;
-                m_inc_y += m_two_rx2;
-                m_cur_f = fxy;
-                m_dx = 1; 
-                m_dy = 1;
-                return;
-            }
-
-            if(flag) 
-            {
-                m_inc_x += m_two_ry2;
-                m_cur_f = fx;
-                m_dx = 1;
-                return;
-            }
-
-            m_inc_y += m_two_rx2;
-            m_cur_f = fy;
-            m_dy = 1;
-        }
-
-    private:
-        int m_rx2;
-        int m_ry2;
-        int m_two_rx2;
-        int m_two_ry2;
-        int m_dx;
-        int m_dy;
-        int m_inc_x;
-        int m_inc_y;
-        int m_cur_f;
-
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_embedded_raster_fonts.h b/xs/src/agg/agg_embedded_raster_fonts.h
deleted file mode 100644
index 9d522d671..000000000
--- a/xs/src/agg/agg_embedded_raster_fonts.h
+++ /dev/null
@@ -1,59 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_EMBEDDED_RASTER_FONTS_INCLUDED
-#define AGG_EMBEDDED_RASTER_FONTS_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    extern const int8u gse4x6[];
-    extern const int8u gse4x8[];
-    extern const int8u gse5x7[];
-    extern const int8u gse5x9[];
-    extern const int8u gse6x12[];
-    extern const int8u gse6x9[];
-    extern const int8u gse7x11[];
-    extern const int8u gse7x11_bold[];
-    extern const int8u gse7x15[];
-    extern const int8u gse7x15_bold[];
-    extern const int8u gse8x16[];
-    extern const int8u gse8x16_bold[];
-    extern const int8u mcs11_prop[];
-    extern const int8u mcs11_prop_condensed[];
-    extern const int8u mcs12_prop[];
-    extern const int8u mcs13_prop[];
-    extern const int8u mcs5x10_mono[];
-    extern const int8u mcs5x11_mono[];
-    extern const int8u mcs6x10_mono[];
-    extern const int8u mcs6x11_mono[];
-    extern const int8u mcs7x12_mono_high[];
-    extern const int8u mcs7x12_mono_low[];
-    extern const int8u verdana12[];
-    extern const int8u verdana12_bold[];
-    extern const int8u verdana13[];
-    extern const int8u verdana13_bold[];
-    extern const int8u verdana14[];
-    extern const int8u verdana14_bold[];
-    extern const int8u verdana16[];
-    extern const int8u verdana16_bold[];
-    extern const int8u verdana17[];
-    extern const int8u verdana17_bold[];
-    extern const int8u verdana18[];
-    extern const int8u verdana18_bold[];
-}
-
-#endif
diff --git a/xs/src/agg/agg_font_cache_manager.h b/xs/src/agg/agg_font_cache_manager.h
deleted file mode 100644
index fe9a9280f..000000000
--- a/xs/src/agg/agg_font_cache_manager.h
+++ /dev/null
@@ -1,409 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_FONT_CACHE_MANAGER_INCLUDED
-#define AGG_FONT_CACHE_MANAGER_INCLUDED
-
-#include <string.h>
-#include "agg_array.h"
-
-namespace agg
-{
-
-    //---------------------------------------------------------glyph_data_type
-    enum glyph_data_type
-    {
-        glyph_data_invalid = 0,
-        glyph_data_mono    = 1,
-        glyph_data_gray8   = 2,
-        glyph_data_outline = 3
-    };
-
-
-    //-------------------------------------------------------------glyph_cache
-    struct glyph_cache
-    {
-        unsigned        glyph_index;
-        int8u*          data;
-        unsigned        data_size;
-        glyph_data_type data_type;
-        rect_i          bounds;
-        double          advance_x;
-        double          advance_y;
-    };
-
-
-    //--------------------------------------------------------------font_cache
-    class font_cache
-    {
-    public:
-        enum block_size_e { block_size = 16384-16 };
-
-        //--------------------------------------------------------------------
-        font_cache() : 
-            m_allocator(block_size),
-            m_font_signature(0)
-        {}
-
-        //--------------------------------------------------------------------
-        void signature(const char* font_signature)
-        {
-            m_font_signature = (char*)m_allocator.allocate(strlen(font_signature) + 1);
-            strcpy(m_font_signature, font_signature);
-            memset(m_glyphs, 0, sizeof(m_glyphs));
-        }
-
-        //--------------------------------------------------------------------
-        bool font_is(const char* font_signature) const
-        {
-            return strcmp(font_signature, m_font_signature) == 0;
-        }
-
-        //--------------------------------------------------------------------
-        const glyph_cache* find_glyph(unsigned glyph_code) const
-        {
-            unsigned msb = (glyph_code >> 8) & 0xFF;
-            if(m_glyphs[msb]) 
-            {
-                return m_glyphs[msb][glyph_code & 0xFF];
-            }
-            return 0;
-        }
-
-        //--------------------------------------------------------------------
-        glyph_cache* cache_glyph(unsigned        glyph_code, 
-                                 unsigned        glyph_index,
-                                 unsigned        data_size,
-                                 glyph_data_type data_type,
-                                 const rect_i&   bounds,
-                                 double          advance_x,
-                                 double          advance_y)
-        {
-            unsigned msb = (glyph_code >> 8) & 0xFF;
-            if(m_glyphs[msb] == 0)
-            {
-                m_glyphs[msb] = 
-                    (glyph_cache**)m_allocator.allocate(sizeof(glyph_cache*) * 256, 
-                                                        sizeof(glyph_cache*));
-                memset(m_glyphs[msb], 0, sizeof(glyph_cache*) * 256);
-            }
-
-            unsigned lsb = glyph_code & 0xFF;
-            if(m_glyphs[msb][lsb]) return 0; // Already exists, do not overwrite
-
-            glyph_cache* glyph = 
-                (glyph_cache*)m_allocator.allocate(sizeof(glyph_cache),
-                                                   sizeof(double));
-
-            glyph->glyph_index        = glyph_index;
-            glyph->data               = m_allocator.allocate(data_size);
-            glyph->data_size          = data_size;
-            glyph->data_type          = data_type;
-            glyph->bounds             = bounds;
-            glyph->advance_x          = advance_x;
-            glyph->advance_y          = advance_y;
-            return m_glyphs[msb][lsb] = glyph;
-        }
-
-    private:
-        block_allocator m_allocator;
-        glyph_cache**   m_glyphs[256];
-        char*           m_font_signature;
-    };
-
-
-
-
-
-
-    
-    //---------------------------------------------------------font_cache_pool
-    class font_cache_pool
-    {
-    public:
-        //--------------------------------------------------------------------
-        ~font_cache_pool()
-        {
-            unsigned i;
-            for(i = 0; i < m_num_fonts; ++i)
-            {
-                obj_allocator<font_cache>::deallocate(m_fonts[i]);
-            }
-            pod_allocator<font_cache*>::deallocate(m_fonts, m_max_fonts);
-        }
-
-        //--------------------------------------------------------------------
-        font_cache_pool(unsigned max_fonts=32) : 
-            m_fonts(pod_allocator<font_cache*>::allocate(max_fonts)),
-            m_max_fonts(max_fonts),
-            m_num_fonts(0),
-            m_cur_font(0)
-        {}
-
-
-        //--------------------------------------------------------------------
-        void font(const char* font_signature, bool reset_cache = false)
-        {
-            int idx = find_font(font_signature);
-            if(idx >= 0)
-            {
-                if(reset_cache)
-                {
-                    obj_allocator<font_cache>::deallocate(m_fonts[idx]);
-                    m_fonts[idx] = obj_allocator<font_cache>::allocate();
-                    m_fonts[idx]->signature(font_signature);
-                }
-                m_cur_font = m_fonts[idx];
-            }
-            else
-            {
-                if(m_num_fonts >= m_max_fonts)
-                {
-                    obj_allocator<font_cache>::deallocate(m_fonts[0]);
-                    memcpy(m_fonts, 
-                           m_fonts + 1, 
-                           (m_max_fonts - 1) * sizeof(font_cache*));
-                    m_num_fonts = m_max_fonts - 1;
-                }
-                m_fonts[m_num_fonts] = obj_allocator<font_cache>::allocate();
-                m_fonts[m_num_fonts]->signature(font_signature);
-                m_cur_font = m_fonts[m_num_fonts];
-                ++m_num_fonts;
-            }
-        }
-
-        //--------------------------------------------------------------------
-        const font_cache* font() const
-        {
-            return m_cur_font;
-        }
-
-        //--------------------------------------------------------------------
-        const glyph_cache* find_glyph(unsigned glyph_code) const
-        {
-            if(m_cur_font) return m_cur_font->find_glyph(glyph_code);
-            return 0;
-        }
-
-        //--------------------------------------------------------------------
-        glyph_cache* cache_glyph(unsigned        glyph_code, 
-                                 unsigned        glyph_index,
-                                 unsigned        data_size,
-                                 glyph_data_type data_type,
-                                 const rect_i&   bounds,
-                                 double          advance_x,
-                                 double          advance_y)
-        {
-            if(m_cur_font) 
-            {
-                return m_cur_font->cache_glyph(glyph_code,
-                                               glyph_index,
-                                               data_size,
-                                               data_type,
-                                               bounds,
-                                               advance_x,
-                                               advance_y);
-            }
-            return 0;
-        }
-
-
-        //--------------------------------------------------------------------
-        int find_font(const char* font_signature)
-        {
-            unsigned i;
-            for(i = 0; i < m_num_fonts; i++)
-            {
-                if(m_fonts[i]->font_is(font_signature)) return int(i);
-            }
-            return -1;
-        }
-
-    private:
-        font_cache** m_fonts;
-        unsigned     m_max_fonts;
-        unsigned     m_num_fonts;
-        font_cache*  m_cur_font;
-    };
-
-
-
-
-    //------------------------------------------------------------------------
-    enum glyph_rendering
-    {
-        glyph_ren_native_mono,
-        glyph_ren_native_gray8,
-        glyph_ren_outline,
-        glyph_ren_agg_mono,
-        glyph_ren_agg_gray8
-    };
-
-
-
-
-    //------------------------------------------------------font_cache_manager
-    template<class FontEngine> class font_cache_manager
-    {
-    public:
-        typedef FontEngine font_engine_type;
-        typedef font_cache_manager<FontEngine> self_type;
-        typedef typename font_engine_type::path_adaptor_type   path_adaptor_type;
-        typedef typename font_engine_type::gray8_adaptor_type  gray8_adaptor_type;
-        typedef typename gray8_adaptor_type::embedded_scanline gray8_scanline_type;
-        typedef typename font_engine_type::mono_adaptor_type   mono_adaptor_type;
-        typedef typename mono_adaptor_type::embedded_scanline  mono_scanline_type;
-
-        //--------------------------------------------------------------------
-        font_cache_manager(font_engine_type& engine, unsigned max_fonts=32) :
-            m_fonts(max_fonts),
-            m_engine(engine),
-            m_change_stamp(-1),
-            m_prev_glyph(0),
-            m_last_glyph(0)
-        {}
-
-        //--------------------------------------------------------------------
-        void reset_last_glyph()
-        {
-            m_prev_glyph = m_last_glyph = 0;
-        }
-
-        //--------------------------------------------------------------------
-        const glyph_cache* glyph(unsigned glyph_code)
-        {
-            synchronize();
-            const glyph_cache* gl = m_fonts.find_glyph(glyph_code);
-            if(gl) 
-            {
-                m_prev_glyph = m_last_glyph;
-                return m_last_glyph = gl;
-            }
-            else
-            {
-                if(m_engine.prepare_glyph(glyph_code))
-                {
-                    m_prev_glyph = m_last_glyph;
-                    m_last_glyph = m_fonts.cache_glyph(glyph_code, 
-                                                       m_engine.glyph_index(),
-                                                       m_engine.data_size(),
-                                                       m_engine.data_type(),
-                                                       m_engine.bounds(),
-                                                       m_engine.advance_x(),
-                                                       m_engine.advance_y());
-                    m_engine.write_glyph_to(m_last_glyph->data);
-                    return m_last_glyph;
-                }
-            }
-            return 0;
-        }
-
-        //--------------------------------------------------------------------
-        void init_embedded_adaptors(const glyph_cache* gl, 
-                                    double x, double y, 
-                                    double scale=1.0)
-        {
-            if(gl)
-            {
-                switch(gl->data_type)
-                {
-                default: return;
-                case glyph_data_mono:
-                    m_mono_adaptor.init(gl->data, gl->data_size, x, y);
-                    break;
-
-                case glyph_data_gray8:
-                    m_gray8_adaptor.init(gl->data, gl->data_size, x, y);
-                    break;
-
-                case glyph_data_outline:
-                    m_path_adaptor.init(gl->data, gl->data_size, x, y, scale);
-                    break;
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        path_adaptor_type&   path_adaptor()   { return m_path_adaptor;   }
-        gray8_adaptor_type&  gray8_adaptor()  { return m_gray8_adaptor;  }
-        gray8_scanline_type& gray8_scanline() { return m_gray8_scanline; }
-        mono_adaptor_type&   mono_adaptor()   { return m_mono_adaptor;   }
-        mono_scanline_type&  mono_scanline()  { return m_mono_scanline;  }
-
-        //--------------------------------------------------------------------
-        const glyph_cache* perv_glyph() const { return m_prev_glyph; }
-        const glyph_cache* last_glyph() const { return m_last_glyph; }
-
-        //--------------------------------------------------------------------
-        bool add_kerning(double* x, double* y)
-        {
-            if(m_prev_glyph && m_last_glyph)
-            {
-                return m_engine.add_kerning(m_prev_glyph->glyph_index, 
-                                            m_last_glyph->glyph_index,
-                                            x, y);
-            }
-            return false;
-        }
-
-        //--------------------------------------------------------------------
-        void precache(unsigned from, unsigned to)
-        {
-            for(; from <= to; ++from) glyph(from);
-        }
-
-        //--------------------------------------------------------------------
-        void reset_cache()
-        {
-            m_fonts.font(m_engine.font_signature(), true);
-            m_change_stamp = m_engine.change_stamp();
-            m_prev_glyph = m_last_glyph = 0;
-        }
-
-    private:
-        //--------------------------------------------------------------------
-        font_cache_manager(const self_type&);
-        const self_type& operator = (const self_type&);
-
-        //--------------------------------------------------------------------
-        void synchronize()
-        {
-            if(m_change_stamp != m_engine.change_stamp())
-            {
-                m_fonts.font(m_engine.font_signature());
-                m_change_stamp = m_engine.change_stamp();
-                m_prev_glyph = m_last_glyph = 0;
-            }
-        }
-
-        font_cache_pool     m_fonts;
-        font_engine_type&   m_engine;
-        int                 m_change_stamp;
-        double              m_dx;
-        double              m_dy;
-        const glyph_cache*  m_prev_glyph;
-        const glyph_cache*  m_last_glyph;
-        path_adaptor_type   m_path_adaptor;
-        gray8_adaptor_type  m_gray8_adaptor;
-        gray8_scanline_type m_gray8_scanline;
-        mono_adaptor_type   m_mono_adaptor;
-        mono_scanline_type  m_mono_scanline;
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_font_cache_manager2.h b/xs/src/agg/agg_font_cache_manager2.h
deleted file mode 100644
index 75d311eff..000000000
--- a/xs/src/agg/agg_font_cache_manager2.h
+++ /dev/null
@@ -1,311 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software
-// is granted provided this copyright notice appears in all copies.
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_FONT_CACHE_MANAGER2_INCLUDED
-#define AGG_FONT_CACHE_MANAGER2_INCLUDED
-
-#include <cassert>
-#include <exception>
-#include <string.h>
-#include "agg_array.h"
-
-namespace agg {
-
-namespace fman {
-  //---------------------------------------------------------glyph_data_type
-  enum glyph_data_type
-  {
-    glyph_data_invalid = 0,
-    glyph_data_mono    = 1,
-    glyph_data_gray8   = 2,
-    glyph_data_outline = 3
-  };
-
-
-  //-------------------------------------------------------------cached_glyph
-  struct cached_glyph
-  {
-    void *			cached_font;
-    unsigned		glyph_code;
-    unsigned        glyph_index;
-    int8u*          data;
-    unsigned        data_size;
-    glyph_data_type data_type;
-    rect_i          bounds;
-    double          advance_x;
-    double          advance_y;
-  };
-
-
-  //--------------------------------------------------------------cached_glyphs
-  class cached_glyphs
-  {
-  public:
-    enum block_size_e { block_size = 16384-16 };
-
-    //--------------------------------------------------------------------
-    cached_glyphs()
-      : m_allocator(block_size)
-    { memset(m_glyphs, 0, sizeof(m_glyphs)); }
-
-    //--------------------------------------------------------------------
-    const cached_glyph* find_glyph(unsigned glyph_code) const
-    {
-      unsigned msb = (glyph_code >> 8) & 0xFF;
-      if(m_glyphs[msb])
-      {
-        return m_glyphs[msb][glyph_code & 0xFF];
-      }
-      return 0;
-    }
-
-    //--------------------------------------------------------------------
-    cached_glyph* cache_glyph(
-      void *			cached_font,
-      unsigned        glyph_code,
-      unsigned        glyph_index,
-      unsigned        data_size,
-      glyph_data_type data_type,
-      const rect_i&   bounds,
-      double          advance_x,
-      double          advance_y)
-    {
-      unsigned msb = (glyph_code >> 8) & 0xFF;
-      if(m_glyphs[msb] == 0)
-      {
-        m_glyphs[msb] =
-          (cached_glyph**)m_allocator.allocate(sizeof(cached_glyph*) * 256,
-          sizeof(cached_glyph*));
-        memset(m_glyphs[msb], 0, sizeof(cached_glyph*) * 256);
-      }
-
-      unsigned lsb = glyph_code & 0xFF;
-      if(m_glyphs[msb][lsb]) return 0; // Already exists, do not overwrite
-
-      cached_glyph* glyph =
-        (cached_glyph*)m_allocator.allocate(sizeof(cached_glyph),
-        sizeof(double));
-
-      glyph->cached_font		  = cached_font;
-      glyph->glyph_code		  = glyph_code;
-      glyph->glyph_index        = glyph_index;
-      glyph->data               = m_allocator.allocate(data_size);
-      glyph->data_size          = data_size;
-      glyph->data_type          = data_type;
-      glyph->bounds             = bounds;
-      glyph->advance_x          = advance_x;
-      glyph->advance_y          = advance_y;
-      return m_glyphs[msb][lsb] = glyph;
-    }
-
-  private:
-    block_allocator m_allocator;
-    cached_glyph**   m_glyphs[256];
-  };
-
-
-
-  //------------------------------------------------------------------------
-  enum glyph_rendering
-  {
-    glyph_ren_native_mono,
-    glyph_ren_native_gray8,
-    glyph_ren_outline,
-    glyph_ren_agg_mono,
-    glyph_ren_agg_gray8
-  };
-
-
-
-
-  //------------------------------------------------------font_cache_manager
-  template<class FontEngine> class font_cache_manager
-  {
-  public:
-    typedef FontEngine font_engine_type;
-    typedef font_cache_manager<FontEngine> self_type;
-    typedef typename font_engine_type::path_adaptor_type   path_adaptor_type;
-    typedef typename font_engine_type::gray8_adaptor_type  gray8_adaptor_type;
-    typedef typename gray8_adaptor_type::embedded_scanline gray8_scanline_type;
-    typedef typename font_engine_type::mono_adaptor_type   mono_adaptor_type;
-    typedef typename mono_adaptor_type::embedded_scanline  mono_scanline_type;
-
-    struct cached_font
-    {
-      cached_font(
-        font_engine_type& engine,
-        typename FontEngine::loaded_face *face,
-        double height,
-        double width,
-        bool hinting,
-        glyph_rendering rendering )
-        : m_engine( engine )
-        , m_face( face )
-        , m_height( height )
-        , m_width( width )
-        , m_hinting( hinting )
-        , m_rendering( rendering )
-      {
-        select_face();
-        m_face_height=m_face->height();
-        m_face_width=m_face->width();
-        m_face_ascent=m_face->ascent();
-        m_face_descent=m_face->descent();
-        m_face_ascent_b=m_face->ascent_b();
-        m_face_descent_b=m_face->descent_b();
-      }
-
-      double height() const
-      {
-        return m_face_height;
-      }
-
-      double width() const
-      {
-        return m_face_width;
-      }
-
-      double ascent() const
-      {
-        return m_face_ascent;
-      }
-
-      double descent() const
-      {
-        return m_face_descent;
-      }
-
-      double ascent_b() const
-      {
-        return m_face_ascent_b;
-      }
-
-      double descent_b() const
-      {
-        return m_face_descent_b;
-      }
-
-      bool add_kerning( const cached_glyph *first, const cached_glyph *second, double* x, double* y)
-      {
-        if( !first || !second )
-          return false;
-        select_face();
-        return m_face->add_kerning(
-          first->glyph_index, second->glyph_index, x, y );
-      }
-
-      void select_face()
-      {
-        m_face->select_instance( m_height, m_width, m_hinting, m_rendering );
-      }
-
-      const cached_glyph *get_glyph(unsigned cp)
-      {
-        const cached_glyph *glyph=m_glyphs.find_glyph(cp);
-        if( glyph==0 )
-        {
-          typename FontEngine::prepared_glyph prepared;
-          select_face();
-          bool success=m_face->prepare_glyph(cp, &prepared);
-          if( success )
-          {
-            glyph=m_glyphs.cache_glyph(
-              this,
-              prepared.glyph_code,
-              prepared.glyph_index,
-              prepared.data_size,
-              prepared.data_type,
-              prepared.bounds,
-              prepared.advance_x,
-              prepared.advance_y );
-            assert( glyph!=0 );
-            m_face->write_glyph_to(&prepared,glyph->data);
-          }
-        }
-        return glyph;
-      }
-
-      font_engine_type&   m_engine;
-      typename FontEngine::loaded_face *m_face;
-      double				m_height;
-      double				m_width;
-      bool				m_hinting;
-      glyph_rendering		m_rendering;
-      double				m_face_height;
-      double				m_face_width;
-      double				m_face_ascent;
-      double				m_face_descent;
-      double				m_face_ascent_b;
-      double				m_face_descent_b;
-      cached_glyphs		m_glyphs;
-    };
-
-    //--------------------------------------------------------------------
-    font_cache_manager(font_engine_type& engine, unsigned max_fonts=32)
-      :m_engine(engine)
-    { }
-
-    //--------------------------------------------------------------------
-    void init_embedded_adaptors(const cached_glyph* gl,
-      double x, double y,
-      double scale=1.0)
-    {
-      if(gl)
-      {
-        switch(gl->data_type)
-        {
-        default: return;
-        case glyph_data_mono:
-          m_mono_adaptor.init(gl->data, gl->data_size, x, y);
-          break;
-
-        case glyph_data_gray8:
-          m_gray8_adaptor.init(gl->data, gl->data_size, x, y);
-          break;
-
-        case glyph_data_outline:
-          m_path_adaptor.init(gl->data, gl->data_size, x, y, scale);
-          break;
-        }
-      }
-    }
-
-
-    //--------------------------------------------------------------------
-    path_adaptor_type&   path_adaptor()   { return m_path_adaptor;   }
-    gray8_adaptor_type&  gray8_adaptor()  { return m_gray8_adaptor;  }
-    gray8_scanline_type& gray8_scanline() { return m_gray8_scanline; }
-    mono_adaptor_type&   mono_adaptor()   { return m_mono_adaptor;   }
-    mono_scanline_type&  mono_scanline()  { return m_mono_scanline;  }
-
-
-  private:
-    //--------------------------------------------------------------------
-    font_cache_manager(const self_type&);
-    const self_type& operator = (const self_type&);
-
-    font_engine_type&   m_engine;
-    path_adaptor_type   m_path_adaptor;
-    gray8_adaptor_type  m_gray8_adaptor;
-    gray8_scanline_type m_gray8_scanline;
-    mono_adaptor_type   m_mono_adaptor;
-    mono_scanline_type  m_mono_scanline;
-  };
-
-}
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_glyph_raster_bin.h b/xs/src/agg/agg_glyph_raster_bin.h
deleted file mode 100644
index b0bf858ef..000000000
--- a/xs/src/agg/agg_glyph_raster_bin.h
+++ /dev/null
@@ -1,155 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_GLYPH_RASTER_BIN_INCLUDED
-#define AGG_GLYPH_RASTER_BIN_INCLUDED
-
-#include <string.h>
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //========================================================glyph_raster_bin
-    template<class ColorT> class glyph_raster_bin
-    {
-    public:
-        typedef ColorT color_type;
-
-        //--------------------------------------------------------------------
-        struct glyph_rect
-        {
-            int x1,y1,x2,y2;
-            double dx, dy;
-        };
-
-        //--------------------------------------------------------------------
-        glyph_raster_bin(const int8u* font) :
-            m_font(font),
-            m_big_endian(false)
-        {
-            int t = 1;
-            if(*(char*)&t == 0) m_big_endian = true;
-            memset(m_span, 0, sizeof(m_span));
-        }
-
-        //--------------------------------------------------------------------
-        const int8u* font() const { return m_font; }
-        void font(const int8u* f) { m_font = f; }
-
-        //--------------------------------------------------------------------
-        double height()    const { return m_font[0]; }
-        double base_line() const { return m_font[1]; }
-
-        //--------------------------------------------------------------------
-        template<class CharT>
-        double width(const CharT* str) const
-        {
-            unsigned start_char = m_font[2];
-            unsigned num_chars = m_font[3];
-
-            unsigned w = 0;
-            while(*str)
-            {
-                unsigned glyph = *str;
-                const int8u* bits = m_font + 4 + num_chars * 2 + 
-                                    value(m_font + 4 + (glyph - start_char) * 2);
-                w += *bits;
-                ++str;
-            }
-            return w;
-        }
-
-        //--------------------------------------------------------------------
-        void prepare(glyph_rect* r, double x, double y, unsigned glyph, bool flip)
-        {
-            unsigned start_char = m_font[2];
-            unsigned num_chars = m_font[3];
-
-            m_bits = m_font + 4 + num_chars * 2 + 
-                     value(m_font + 4 + (glyph - start_char) * 2);
-
-            m_glyph_width = *m_bits++;
-            m_glyph_byte_width = (m_glyph_width + 7) >> 3;
-
-            r->x1 = int(x);
-            r->x2 = r->x1 + m_glyph_width - 1;
-            if(flip)
-            {
-                r->y1 = int(y) - m_font[0] + m_font[1];
-                r->y2 = r->y1 + m_font[0] - 1;
-            }
-            else
-            {
-                r->y1 = int(y) - m_font[1] + 1;
-                r->y2 = r->y1 + m_font[0] - 1;
-            }
-            r->dx = m_glyph_width; 
-            r->dy = 0;
-        }
-
-        //--------------------------------------------------------------------
-        const cover_type* span(unsigned i)
-        {
-            i = m_font[0] - i - 1;
-            const int8u* bits = m_bits + i * m_glyph_byte_width;
-            unsigned j;
-            unsigned val = *bits;
-            unsigned nb = 0;
-            for(j = 0; j < m_glyph_width; ++j)
-            {
-                m_span[j] = (cover_type)((val & 0x80) ? cover_full : cover_none);
-                val <<= 1;
-                if(++nb >= 8)
-                {
-                    val = *++bits;
-                    nb = 0;
-                }
-            }
-            return m_span;
-        }
-
-    private:
-        //--------------------------------------------------------------------
-        int16u value(const int8u* p) const
-        {
-            int16u v;
-            if(m_big_endian)
-            {
-                 *(int8u*)&v      = p[1];
-                *((int8u*)&v + 1) = p[0];
-            }
-            else
-            {
-                 *(int8u*)&v      = p[0];
-                *((int8u*)&v + 1) = p[1];
-            }
-            return v;
-        }
-
-
-        //--------------------------------------------------------------------
-        const int8u* m_font;
-        bool m_big_endian;
-        cover_type m_span[32];
-        const int8u* m_bits;
-        unsigned m_glyph_width;
-        unsigned m_glyph_byte_width;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_gradient_lut.h b/xs/src/agg/agg_gradient_lut.h
deleted file mode 100644
index 9aaa42681..000000000
--- a/xs/src/agg/agg_gradient_lut.h
+++ /dev/null
@@ -1,244 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_GRADIENT_LUT_INCLUDED
-#define AGG_GRADIENT_LUT_INCLUDED
-
-#include "agg_array.h"
-#include "agg_dda_line.h"
-#include "agg_color_rgba.h"
-#include "agg_color_gray.h"
-
-namespace agg
-{
-
-    //======================================================color_interpolator
-    template<class ColorT> struct color_interpolator
-    {
-    public:
-        typedef ColorT color_type;
-
-        color_interpolator(const color_type& c1, 
-                           const color_type& c2, 
-                           unsigned len) :
-            m_c1(c1),
-            m_c2(c2),
-            m_len(len),
-            m_count(0)
-        {}
-
-        void operator ++ ()
-        {
-            ++m_count;
-        }
-
-        color_type color() const
-        {
-            return m_c1.gradient(m_c2, double(m_count) / m_len);
-        }
-
-    private:
-        color_type m_c1;
-        color_type m_c2;
-        unsigned   m_len;
-        unsigned   m_count;
-    };
-
-    //========================================================================
-    // Fast specialization for rgba8
-    template<> struct color_interpolator<rgba8>
-    {
-    public:
-        typedef rgba8 color_type;
-
-        color_interpolator(const color_type& c1, 
-                           const color_type& c2, 
-                           unsigned len) :
-            r(c1.r, c2.r, len),
-            g(c1.g, c2.g, len),
-            b(c1.b, c2.b, len),
-            a(c1.a, c2.a, len)
-        {}
-
-        void operator ++ ()
-        {
-            ++r; ++g; ++b; ++a;
-        }
-
-        color_type color() const
-        {
-            return color_type(r.y(), g.y(), b.y(), a.y());
-        }
-
-    private:
-        agg::dda_line_interpolator<14> r, g, b, a;
-    };
-
-    //========================================================================
-    // Fast specialization for gray8
-    template<> struct color_interpolator<gray8>
-    {
-    public:
-        typedef gray8 color_type;
-
-        color_interpolator(const color_type& c1, 
-                           const color_type& c2, 
-                           unsigned len) :
-            v(c1.v, c2.v, len),
-            a(c1.a, c2.a, len)
-        {}
-
-        void operator ++ ()
-        {
-            ++v; ++a;
-        }
-
-        color_type color() const
-        {
-            return color_type(v.y(), a.y());
-        }
-
-    private:
-        agg::dda_line_interpolator<14> v,a;
-    };
-
-    //============================================================gradient_lut
-    template<class ColorInterpolator, 
-             unsigned ColorLutSize=256> class gradient_lut
-    {
-    public:
-        typedef ColorInterpolator interpolator_type;
-        typedef typename interpolator_type::color_type color_type;
-        enum { color_lut_size = ColorLutSize };
-
-        //--------------------------------------------------------------------
-        gradient_lut() : m_color_lut(color_lut_size) {}
-
-        // Build Gradient Lut
-        // First, call remove_all(), then add_color() at least twice, 
-        // then build_lut(). Argument "offset" in add_color must be 
-        // in range [0...1] and defines a color stop as it is described 
-        // in SVG specification, section Gradients and Patterns. 
-        // The simplest linear gradient is:
-        //    gradient_lut.add_color(0.0, start_color);
-        //    gradient_lut.add_color(1.0, end_color);
-        //--------------------------------------------------------------------
-        void remove_all();
-        void add_color(double offset, const color_type& color);
-        void build_lut();
-
-        // Size-index Interface. This class can be used directly as the 
-        // ColorF in span_gradient. All it needs is two access methods 
-        // size() and operator [].
-        //--------------------------------------------------------------------
-        static unsigned size() 
-        { 
-            return color_lut_size; 
-        }
-        const color_type& operator [] (unsigned i) const 
-        { 
-            return m_color_lut[i]; 
-        }
-
-    private:
-        //--------------------------------------------------------------------
-        struct color_point
-        {
-            double     offset;
-            color_type color;
-
-            color_point() {}
-            color_point(double off, const color_type& c) : 
-                offset(off), color(c)
-            {
-                if(offset < 0.0) offset = 0.0;
-                if(offset > 1.0) offset = 1.0;
-            }
-        };
-        typedef agg::pod_bvector<color_point, 4> color_profile_type;
-        typedef agg::pod_array<color_type>       color_lut_type;
-
-        static bool offset_less(const color_point& a, const color_point& b)
-        {
-            return a.offset < b.offset;
-        }
-        static bool offset_equal(const color_point& a, const color_point& b)
-        {
-            return a.offset == b.offset;
-        }
-
-        //--------------------------------------------------------------------
-        color_profile_type  m_color_profile;
-        color_lut_type      m_color_lut;
-    };
-
-
-
-    //------------------------------------------------------------------------
-    template<class T, unsigned S>
-    void gradient_lut<T,S>::remove_all()
-    { 
-        m_color_profile.remove_all(); 
-    }
-
-    //------------------------------------------------------------------------
-    template<class T, unsigned S>
-    void gradient_lut<T,S>::add_color(double offset, const color_type& color)
-    {
-        m_color_profile.add(color_point(offset, color));
-    }
-
-    //------------------------------------------------------------------------
-    template<class T, unsigned S>
-    void gradient_lut<T,S>::build_lut()
-    {
-        quick_sort(m_color_profile, offset_less);
-        m_color_profile.cut_at(remove_duplicates(m_color_profile, offset_equal));
-        if(m_color_profile.size() >= 2)
-        {
-            unsigned i;
-            unsigned start = uround(m_color_profile[0].offset * color_lut_size);
-            unsigned end;
-            color_type c = m_color_profile[0].color;
-            for(i = 0; i < start; i++) 
-            {
-                m_color_lut[i] = c;
-            }
-            for(i = 1; i < m_color_profile.size(); i++)
-            {
-                end  = uround(m_color_profile[i].offset * color_lut_size);
-                interpolator_type ci(m_color_profile[i-1].color, 
-                                     m_color_profile[i  ].color, 
-                                     end - start + 1);
-                while(start < end)
-                {
-                    m_color_lut[start] = ci.color();
-                    ++ci;
-                    ++start;
-                }
-            }
-            c = m_color_profile.last().color;
-            for(; end < m_color_lut.size(); end++)
-            {
-                m_color_lut[end] = c;
-            }
-        }
-    }
-}
-
-
-
-
-#endif
diff --git a/xs/src/agg/agg_gsv_text.h b/xs/src/agg/agg_gsv_text.h
deleted file mode 100644
index 16b3aeb33..000000000
--- a/xs/src/agg/agg_gsv_text.h
+++ /dev/null
@@ -1,153 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Class gsv_text
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_GSV_TEXT_INCLUDED
-#define AGG_GSV_TEXT_INCLUDED
-
-#include "agg_array.h"
-#include "agg_conv_stroke.h"
-#include "agg_conv_transform.h"
-
-namespace agg
-{
-
-
-    //---------------------------------------------------------------gsv_text
-    //
-    // See Implementation agg_gsv_text.cpp 
-    //
-    class gsv_text
-    {
-        enum status
-        {
-            initial,
-            next_char,
-            start_glyph,
-            glyph
-        };
-
-    public:
-        gsv_text();
-
-        void font(const void* font);
-        void flip(bool flip_y) { m_flip = flip_y; }
-        void load_font(const char* file);
-        void size(double height, double width=0.0);
-        void space(double space);
-        void line_space(double line_space);
-        void start_point(double x, double y);
-        void text(const char* text);
-        
-        double text_width();
-
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        // not supposed to be copied
-        gsv_text(const gsv_text&);
-        const gsv_text& operator = (const gsv_text&);
-
-        int16u value(const int8u* p) const
-        {
-            int16u v;
-            if(m_big_endian)
-            {
-                 *(int8u*)&v      = p[1];
-                *((int8u*)&v + 1) = p[0];
-            }
-            else
-            {
-                 *(int8u*)&v      = p[0];
-                *((int8u*)&v + 1) = p[1];
-            }
-            return v;
-        }
-
-    private:
-        double          m_x;
-        double          m_y;
-        double          m_start_x;
-        double          m_width;
-        double          m_height;
-        double          m_space;
-        double          m_line_space;
-        char            m_chr[2];
-        char*           m_text;
-        pod_array<char> m_text_buf;
-        char*           m_cur_chr;
-        const void*     m_font;
-        pod_array<char> m_loaded_font;
-        status          m_status;
-        bool            m_big_endian;
-        bool            m_flip;
-        int8u*          m_indices;
-        int8*           m_glyphs;
-        int8*           m_bglyph;
-        int8*           m_eglyph;
-        double          m_w;
-        double          m_h;
-    };
-
-
-
-
-    //--------------------------------------------------------gsv_text_outline
-    template<class Transformer = trans_affine> class gsv_text_outline
-    {
-    public:
-        gsv_text_outline(gsv_text& text, Transformer& trans) :
-          m_polyline(text),
-          m_trans(m_polyline, trans)
-        {
-        }
-
-        void width(double w) 
-        { 
-            m_polyline.width(w); 
-        }
-
-        void transformer(const Transformer* trans) 
-        {
-            m_trans->transformer(trans);
-        }
-
-        void rewind(unsigned path_id) 
-        { 
-            m_trans.rewind(path_id); 
-            m_polyline.line_join(round_join);
-            m_polyline.line_cap(round_cap);
-        }
-
-        unsigned vertex(double* x, double* y)
-        {
-            return m_trans.vertex(x, y);
-        }
-
-    private:
-        conv_stroke<gsv_text> m_polyline;
-        conv_transform<conv_stroke<gsv_text>, Transformer> m_trans;
-    };
-
-
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_image_accessors.h b/xs/src/agg/agg_image_accessors.h
deleted file mode 100644
index c651d6d2e..000000000
--- a/xs/src/agg/agg_image_accessors.h
+++ /dev/null
@@ -1,481 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_IMAGE_ACCESSORS_INCLUDED
-#define AGG_IMAGE_ACCESSORS_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //-----------------------------------------------------image_accessor_clip
-    template<class PixFmt> class image_accessor_clip
-    {
-    public:
-        typedef PixFmt   pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::order_type order_type;
-        typedef typename pixfmt_type::value_type value_type;
-        enum pix_width_e { pix_width = pixfmt_type::pix_width };
-
-        image_accessor_clip() {}
-        explicit image_accessor_clip(pixfmt_type& pixf, 
-                                     const color_type& bk) : 
-            m_pixf(&pixf)
-        {
-            pixfmt_type::make_pix(m_bk_buf, bk);
-        }
-
-        void attach(pixfmt_type& pixf)
-        {
-            m_pixf = &pixf;
-        }
-
-        void background_color(const color_type& bk)
-        {
-            pixfmt_type::make_pix(m_bk_buf, bk);
-        }
-
-    private:
-        AGG_INLINE const int8u* pixel() const
-        {
-            if(m_y >= 0 && m_y < (int)m_pixf->height() &&
-               m_x >= 0 && m_x < (int)m_pixf->width())
-            {
-                return m_pixf->pix_ptr(m_x, m_y);
-            }
-            return m_bk_buf;
-        }
-
-    public:
-        AGG_INLINE const int8u* span(int x, int y, unsigned len)
-        {
-            m_x = m_x0 = x;
-            m_y = y;
-            if(y >= 0 && y < (int)m_pixf->height() &&
-               x >= 0 && x+(int)len <= (int)m_pixf->width())
-            {
-                return m_pix_ptr = m_pixf->pix_ptr(x, y);
-            }
-            m_pix_ptr = 0;
-            return pixel();
-        }
-
-        AGG_INLINE const int8u* next_x()
-        {
-            if(m_pix_ptr) return m_pix_ptr += pix_width;
-            ++m_x;
-            return pixel();
-        }
-
-        AGG_INLINE const int8u* next_y()
-        {
-            ++m_y;
-            m_x = m_x0;
-            if(m_pix_ptr && 
-               m_y >= 0 && m_y < (int)m_pixf->height())
-            {
-                return m_pix_ptr = m_pixf->pix_ptr(m_x, m_y);
-            }
-            m_pix_ptr = 0;
-            return pixel();
-        }
-
-    private:
-        const pixfmt_type* m_pixf;
-        int8u              m_bk_buf[pix_width];
-        int                m_x, m_x0, m_y;
-        const int8u*       m_pix_ptr;
-    };
-
-
-
-
-    //--------------------------------------------------image_accessor_no_clip
-    template<class PixFmt> class image_accessor_no_clip
-    {
-    public:
-        typedef PixFmt   pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::order_type order_type;
-        typedef typename pixfmt_type::value_type value_type;
-        enum pix_width_e { pix_width = pixfmt_type::pix_width };
-
-        image_accessor_no_clip() {}
-        explicit image_accessor_no_clip(pixfmt_type& pixf) : 
-            m_pixf(&pixf) 
-        {}
-
-        void attach(pixfmt_type& pixf)
-        {
-            m_pixf = &pixf;
-        }
-
-        AGG_INLINE const int8u* span(int x, int y, unsigned)
-        {
-            m_x = x;
-            m_y = y;
-            return m_pix_ptr = m_pixf->pix_ptr(x, y);
-        }
-
-        AGG_INLINE const int8u* next_x()
-        {
-            return m_pix_ptr += pix_width;
-        }
-
-        AGG_INLINE const int8u* next_y()
-        {
-            ++m_y;
-            return m_pix_ptr = m_pixf->pix_ptr(m_x, m_y);
-        }
-
-    private:
-        const pixfmt_type* m_pixf;
-        int                m_x, m_y;
-        const int8u*       m_pix_ptr;
-    };
-
-
-
-
-    //----------------------------------------------------image_accessor_clone
-    template<class PixFmt> class image_accessor_clone
-    {
-    public:
-        typedef PixFmt   pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::order_type order_type;
-        typedef typename pixfmt_type::value_type value_type;
-        enum pix_width_e { pix_width = pixfmt_type::pix_width };
-
-        image_accessor_clone() {}
-        explicit image_accessor_clone(pixfmt_type& pixf) : 
-            m_pixf(&pixf) 
-        {}
-
-        void attach(pixfmt_type& pixf)
-        {
-            m_pixf = &pixf;
-        }
-
-    private:
-        AGG_INLINE const int8u* pixel() const
-        {
-            int x = m_x;
-            int y = m_y;
-            if(x < 0) x = 0;
-            if(y < 0) y = 0;
-            if(x >= (int)m_pixf->width())  x = m_pixf->width() - 1;
-            if(y >= (int)m_pixf->height()) y = m_pixf->height() - 1;
-            return m_pixf->pix_ptr(x, y);
-        }
-
-    public:
-        AGG_INLINE const int8u* span(int x, int y, unsigned len)
-        {
-            m_x = m_x0 = x;
-            m_y = y;
-            if(y >= 0 && y < (int)m_pixf->height() &&
-               x >= 0 && x+len <= (int)m_pixf->width())
-            {
-                return m_pix_ptr = m_pixf->pix_ptr(x, y);
-            }
-            m_pix_ptr = 0;
-            return pixel();
-        }
-
-        AGG_INLINE const int8u* next_x()
-        {
-            if(m_pix_ptr) return m_pix_ptr += pix_width;
-            ++m_x;
-            return pixel();
-        }
-
-        AGG_INLINE const int8u* next_y()
-        {
-            ++m_y;
-            m_x = m_x0;
-            if(m_pix_ptr && 
-               m_y >= 0 && m_y < (int)m_pixf->height())
-            {
-                return m_pix_ptr = m_pixf->pix_ptr(m_x, m_y);
-            }
-            m_pix_ptr = 0;
-            return pixel();
-        }
-
-    private:
-        const pixfmt_type* m_pixf;
-        int                m_x, m_x0, m_y;
-        const int8u*       m_pix_ptr;
-    };
-
-
-
-
-
-    //-----------------------------------------------------image_accessor_wrap
-    template<class PixFmt, class WrapX, class WrapY> class image_accessor_wrap
-    {
-    public:
-        typedef PixFmt   pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::order_type order_type;
-        typedef typename pixfmt_type::value_type value_type;
-        enum pix_width_e { pix_width = pixfmt_type::pix_width };
-
-        image_accessor_wrap() {}
-        explicit image_accessor_wrap(pixfmt_type& pixf) : 
-            m_pixf(&pixf), 
-            m_wrap_x(pixf.width()), 
-            m_wrap_y(pixf.height())
-        {}
-
-        void attach(pixfmt_type& pixf)
-        {
-            m_pixf = &pixf;
-        }
-
-        AGG_INLINE const int8u* span(int x, int y, unsigned)
-        {
-            m_x = x;
-            m_row_ptr = m_pixf->pix_ptr(0, m_wrap_y(y));
-            return m_row_ptr + m_wrap_x(x) * pix_width;
-        }
-
-        AGG_INLINE const int8u* next_x()
-        {
-            int x = ++m_wrap_x;
-            return m_row_ptr + x * pix_width;
-        }
-
-        AGG_INLINE const int8u* next_y()
-        {
-            m_row_ptr = m_pixf->pix_ptr(0, ++m_wrap_y);
-            return m_row_ptr + m_wrap_x(m_x) * pix_width;
-        }
-
-    private:
-        const pixfmt_type* m_pixf;
-        const int8u*       m_row_ptr;
-        int                m_x;
-        WrapX              m_wrap_x;
-        WrapY              m_wrap_y;
-    };
-
-
-
-
-    //--------------------------------------------------------wrap_mode_repeat
-    class wrap_mode_repeat
-    {
-    public:
-        wrap_mode_repeat() {}
-        wrap_mode_repeat(unsigned size) : 
-            m_size(size), 
-            m_add(size * (0x3FFFFFFF / size)),
-            m_value(0)
-        {}
-
-        AGG_INLINE unsigned operator() (int v)
-        { 
-            return m_value = (unsigned(v) + m_add) % m_size; 
-        }
-
-        AGG_INLINE unsigned operator++ ()
-        {
-            ++m_value;
-            if(m_value >= m_size) m_value = 0;
-            return m_value;
-        }
-    private:
-        unsigned m_size;
-        unsigned m_add;
-        unsigned m_value;
-    };
-
-
-    //---------------------------------------------------wrap_mode_repeat_pow2
-    class wrap_mode_repeat_pow2
-    {
-    public:
-        wrap_mode_repeat_pow2() {}
-        wrap_mode_repeat_pow2(unsigned size) : m_value(0)
-        {
-            m_mask = 1;
-            while(m_mask < size) m_mask = (m_mask << 1) | 1;
-            m_mask >>= 1;
-        }
-        AGG_INLINE unsigned operator() (int v)
-        { 
-            return m_value = unsigned(v) & m_mask;
-        }
-        AGG_INLINE unsigned operator++ ()
-        {
-            ++m_value;
-            if(m_value > m_mask) m_value = 0;
-            return m_value;
-        }
-    private:
-        unsigned m_mask;
-        unsigned m_value;
-    };
-
-
-    //----------------------------------------------wrap_mode_repeat_auto_pow2
-    class wrap_mode_repeat_auto_pow2
-    {
-    public:
-        wrap_mode_repeat_auto_pow2() {}
-        wrap_mode_repeat_auto_pow2(unsigned size) :
-            m_size(size),
-            m_add(size * (0x3FFFFFFF / size)),
-            m_mask((m_size & (m_size-1)) ? 0 : m_size-1),
-            m_value(0)
-        {}
-
-        AGG_INLINE unsigned operator() (int v) 
-        { 
-            if(m_mask) return m_value = unsigned(v) & m_mask;
-            return m_value = (unsigned(v) + m_add) % m_size;
-        }
-        AGG_INLINE unsigned operator++ ()
-        {
-            ++m_value;
-            if(m_value >= m_size) m_value = 0;
-            return m_value;
-        }
-
-    private:
-        unsigned m_size;
-        unsigned m_add;
-        unsigned m_mask;
-        unsigned m_value;
-    };
-
-
-    //-------------------------------------------------------wrap_mode_reflect
-    class wrap_mode_reflect
-    {
-    public:
-        wrap_mode_reflect() {}
-        wrap_mode_reflect(unsigned size) : 
-            m_size(size), 
-            m_size2(size * 2),
-            m_add(m_size2 * (0x3FFFFFFF / m_size2)),
-            m_value(0)
-        {}
-
-        AGG_INLINE unsigned operator() (int v)
-        { 
-            m_value = (unsigned(v) + m_add) % m_size2;
-            if(m_value >= m_size) return m_size2 - m_value - 1;
-            return m_value;
-        }
-
-        AGG_INLINE unsigned operator++ ()
-        {
-            ++m_value;
-            if(m_value >= m_size2) m_value = 0;
-            if(m_value >= m_size) return m_size2 - m_value - 1;
-            return m_value;
-        }
-    private:
-        unsigned m_size;
-        unsigned m_size2;
-        unsigned m_add;
-        unsigned m_value;
-    };
-
-
-
-    //--------------------------------------------------wrap_mode_reflect_pow2
-    class wrap_mode_reflect_pow2
-    {
-    public:
-        wrap_mode_reflect_pow2() {}
-        wrap_mode_reflect_pow2(unsigned size) : m_value(0)
-        {
-            m_mask = 1;
-            m_size = 1;
-            while(m_mask < size) 
-            {
-                m_mask = (m_mask << 1) | 1;
-                m_size <<= 1;
-            }
-        }
-        AGG_INLINE unsigned operator() (int v)
-        { 
-            m_value = unsigned(v) & m_mask;
-            if(m_value >= m_size) return m_mask - m_value;
-            return m_value;
-        }
-        AGG_INLINE unsigned operator++ ()
-        {
-            ++m_value;
-            m_value &= m_mask;
-            if(m_value >= m_size) return m_mask - m_value;
-            return m_value;
-        }
-    private:
-        unsigned m_size;
-        unsigned m_mask;
-        unsigned m_value;
-    };
-
-
-
-    //---------------------------------------------wrap_mode_reflect_auto_pow2
-    class wrap_mode_reflect_auto_pow2
-    {
-    public:
-        wrap_mode_reflect_auto_pow2() {}
-        wrap_mode_reflect_auto_pow2(unsigned size) :
-            m_size(size),
-            m_size2(size * 2),
-            m_add(m_size2 * (0x3FFFFFFF / m_size2)),
-            m_mask((m_size2 & (m_size2-1)) ? 0 : m_size2-1),
-            m_value(0)
-        {}
-
-        AGG_INLINE unsigned operator() (int v) 
-        { 
-            m_value = m_mask ? unsigned(v) & m_mask : 
-                              (unsigned(v) + m_add) % m_size2;
-            if(m_value >= m_size) return m_size2 - m_value - 1;
-            return m_value;            
-        }
-        AGG_INLINE unsigned operator++ ()
-        {
-            ++m_value;
-            if(m_value >= m_size2) m_value = 0;
-            if(m_value >= m_size) return m_size2 - m_value - 1;
-            return m_value;
-        }
-
-    private:
-        unsigned m_size;
-        unsigned m_size2;
-        unsigned m_add;
-        unsigned m_mask;
-        unsigned m_value;
-    };
-
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_image_filters.h b/xs/src/agg/agg_image_filters.h
deleted file mode 100644
index 0e7c598da..000000000
--- a/xs/src/agg/agg_image_filters.h
+++ /dev/null
@@ -1,449 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Image transformation filters,
-// Filtering classes (image_filter_lut, image_filter),
-// Basic filter shape classes
-//----------------------------------------------------------------------------
-#ifndef AGG_IMAGE_FILTERS_INCLUDED
-#define AGG_IMAGE_FILTERS_INCLUDED
-
-#include "agg_array.h"
-#include "agg_math.h"
-
-namespace agg
-{
-
-    // See Implementation agg_image_filters.cpp 
-
-    enum image_filter_scale_e
-    {
-        image_filter_shift = 14,                      //----image_filter_shift
-        image_filter_scale = 1 << image_filter_shift, //----image_filter_scale 
-        image_filter_mask  = image_filter_scale - 1   //----image_filter_mask 
-    };
-
-    enum image_subpixel_scale_e
-    {
-        image_subpixel_shift = 8,                         //----image_subpixel_shift
-        image_subpixel_scale = 1 << image_subpixel_shift, //----image_subpixel_scale 
-        image_subpixel_mask  = image_subpixel_scale - 1   //----image_subpixel_mask 
-    };
-
-
-    //-----------------------------------------------------image_filter_lut
-    class image_filter_lut
-    {
-    public:
-        template<class FilterF> void calculate(const FilterF& filter,
-                                               bool normalization=true)
-        {
-			filter; // prevent erroneous C4100 in MSVC
-            double r = filter.radius();
-            realloc_lut(r);
-            unsigned i;
-            unsigned pivot = diameter() << (image_subpixel_shift - 1);
-            for(i = 0; i < pivot; i++)
-            {
-                double x = double(i) / double(image_subpixel_scale);
-                double y = filter.calc_weight(x);
-                m_weight_array[pivot + i] = 
-                m_weight_array[pivot - i] = (int16)iround(y * image_filter_scale);
-            }
-            unsigned end = (diameter() << image_subpixel_shift) - 1;
-            m_weight_array[0] = m_weight_array[end];
-            if(normalization) 
-            {
-                normalize();
-            }
-        }
-
-        image_filter_lut() : m_radius(0), m_diameter(0), m_start(0) {}
-
-        template<class FilterF> image_filter_lut(const FilterF& filter, 
-                                                 bool normalization=true)
-        {
-            calculate(filter, normalization);
-        }
-
-        double       radius()       const { return m_radius;   }
-        unsigned     diameter()     const { return m_diameter; }
-        int          start()        const { return m_start;    }
-        const int16* weight_array() const { return &m_weight_array[0]; }
-        void         normalize();
-
-    private:
-        void realloc_lut(double radius);
-        image_filter_lut(const image_filter_lut&);
-        const image_filter_lut& operator = (const image_filter_lut&);
-
-        double           m_radius;
-        unsigned         m_diameter;
-        int              m_start;
-        pod_array<int16> m_weight_array;
-    };
-
-
-
-    //--------------------------------------------------------image_filter
-    template<class FilterF> class image_filter : public image_filter_lut
-    {
-    public:
-        image_filter()
-        {
-            calculate(m_filter_function);
-        }
-    private:
-        FilterF m_filter_function;
-    };
-
-
-    //-----------------------------------------------image_filter_bilinear
-    struct image_filter_bilinear
-    {
-        static double radius() { return 1.0; }
-        static double calc_weight(double x)
-        {
-            return 1.0 - x;
-        }
-    };
-
-
-    //-----------------------------------------------image_filter_hanning
-    struct image_filter_hanning
-    {
-        static double radius() { return 1.0; }
-        static double calc_weight(double x)
-        {
-            return 0.5 + 0.5 * cos(pi * x);
-        }
-    };
-
-
-    //-----------------------------------------------image_filter_hamming
-    struct image_filter_hamming
-    {
-        static double radius() { return 1.0; }
-        static double calc_weight(double x)
-        {
-            return 0.54 + 0.46 * cos(pi * x);
-        }
-    };
-
-    //-----------------------------------------------image_filter_hermite
-    struct image_filter_hermite
-    {
-        static double radius() { return 1.0; }
-        static double calc_weight(double x)
-        {
-            return (2.0 * x - 3.0) * x * x + 1.0;
-        }
-    };
-   
-    //------------------------------------------------image_filter_quadric
-    struct image_filter_quadric
-    {
-        static double radius() { return 1.5; }
-        static double calc_weight(double x)
-        {
-            double t;
-            if(x <  0.5) return 0.75 - x * x;
-            if(x <  1.5) {t = x - 1.5; return 0.5 * t * t;}
-            return 0.0;
-        }
-    };
-
-    //------------------------------------------------image_filter_bicubic
-    class image_filter_bicubic
-    {
-        static double pow3(double x)
-        {
-            return (x <= 0.0) ? 0.0 : x * x * x;
-        }
-
-    public:
-        static double radius() { return 2.0; }
-        static double calc_weight(double x)
-        {
-            return
-                (1.0/6.0) * 
-                (pow3(x + 2) - 4 * pow3(x + 1) + 6 * pow3(x) - 4 * pow3(x - 1));
-        }
-    };
-
-    //-------------------------------------------------image_filter_kaiser
-    class image_filter_kaiser
-    {
-        double a;
-        double i0a;
-        double epsilon;
-
-    public:
-        image_filter_kaiser(double b = 6.33) :
-            a(b), epsilon(1e-12)
-        {
-            i0a = 1.0 / bessel_i0(b);
-        }
-
-        static double radius() { return 1.0; }
-        double calc_weight(double x) const
-        {
-            return bessel_i0(a * sqrt(1. - x * x)) * i0a;
-        }
-
-    private:
-        double bessel_i0(double x) const
-        {
-            int i;
-            double sum, y, t;
-
-            sum = 1.;
-            y = x * x / 4.;
-            t = y;
-        
-            for(i = 2; t > epsilon; i++)
-            {
-                sum += t;
-                t *= (double)y / (i * i);
-            }
-            return sum;
-        }
-    };
-
-    //----------------------------------------------image_filter_catrom
-    struct image_filter_catrom
-    {
-        static double radius() { return 2.0; }
-        static double calc_weight(double x)
-        {
-            if(x <  1.0) return 0.5 * (2.0 + x * x * (-5.0 + x * 3.0));
-            if(x <  2.0) return 0.5 * (4.0 + x * (-8.0 + x * (5.0 - x)));
-            return 0.;
-        }
-    };
-
-    //---------------------------------------------image_filter_mitchell
-    class image_filter_mitchell
-    {
-        double p0, p2, p3;
-        double q0, q1, q2, q3;
-
-    public:
-        image_filter_mitchell(double b = 1.0/3.0, double c = 1.0/3.0) :
-            p0((6.0 - 2.0 * b) / 6.0),
-            p2((-18.0 + 12.0 * b + 6.0 * c) / 6.0),
-            p3((12.0 - 9.0 * b - 6.0 * c) / 6.0),
-            q0((8.0 * b + 24.0 * c) / 6.0),
-            q1((-12.0 * b - 48.0 * c) / 6.0),
-            q2((6.0 * b + 30.0 * c) / 6.0),
-            q3((-b - 6.0 * c) / 6.0)
-        {}
-
-        static double radius() { return 2.0; }
-        double calc_weight(double x) const
-        {
-            if(x < 1.0) return p0 + x * x * (p2 + x * p3);
-            if(x < 2.0) return q0 + x * (q1 + x * (q2 + x * q3));
-            return 0.0;
-        }
-    };
-
-
-    //----------------------------------------------image_filter_spline16
-    struct image_filter_spline16
-    {
-        static double radius() { return 2.0; }
-        static double calc_weight(double x)
-        {
-            if(x < 1.0)
-            {
-                return ((x - 9.0/5.0 ) * x - 1.0/5.0 ) * x + 1.0;
-            }
-            return ((-1.0/3.0 * (x-1) + 4.0/5.0) * (x-1) - 7.0/15.0 ) * (x-1);
-        }
-    };
-
-
-    //---------------------------------------------image_filter_spline36
-    struct image_filter_spline36
-    {
-        static double radius() { return 3.0; }
-        static double calc_weight(double x)
-        {
-           if(x < 1.0)
-           {
-              return ((13.0/11.0 * x - 453.0/209.0) * x - 3.0/209.0) * x + 1.0;
-           }
-           if(x < 2.0)
-           {
-              return ((-6.0/11.0 * (x-1) + 270.0/209.0) * (x-1) - 156.0/ 209.0) * (x-1);
-           }
-           return ((1.0/11.0 * (x-2) - 45.0/209.0) * (x-2) +  26.0/209.0) * (x-2);
-        }
-    };
-
-
-    //----------------------------------------------image_filter_gaussian
-    struct image_filter_gaussian
-    {
-        static double radius() { return 2.0; }
-        static double calc_weight(double x) 
-        {
-            return exp(-2.0 * x * x) * sqrt(2.0 / pi);
-        }
-    };
-
-
-    //------------------------------------------------image_filter_bessel
-    struct image_filter_bessel
-    {
-        static double radius() { return 3.2383; } 
-        static double calc_weight(double x)
-        {
-            return (x == 0.0) ? pi / 4.0 : besj(pi * x, 1) / (2.0 * x);
-        }
-    };
-
-
-    //-------------------------------------------------image_filter_sinc
-    class image_filter_sinc
-    {
-    public:
-        image_filter_sinc(double r) : m_radius(r < 2.0 ? 2.0 : r) {}
-        double radius() const { return m_radius; }
-        double calc_weight(double x) const
-        {
-            if(x == 0.0) return 1.0;
-            x *= pi;
-            return sin(x) / x;
-        }
-    private:
-        double m_radius;
-    };
-
-
-    //-----------------------------------------------image_filter_lanczos
-    class image_filter_lanczos
-    {
-    public:
-        image_filter_lanczos(double r) : m_radius(r < 2.0 ? 2.0 : r) {}
-        double radius() const { return m_radius; }
-        double calc_weight(double x) const
-        {
-           if(x == 0.0) return 1.0;
-           if(x > m_radius) return 0.0;
-           x *= pi;
-           double xr = x / m_radius;
-           return (sin(x) / x) * (sin(xr) / xr);
-        }
-    private:
-        double m_radius;
-    };
-
-
-    //----------------------------------------------image_filter_blackman
-    class image_filter_blackman
-    {
-    public:
-        image_filter_blackman(double r) : m_radius(r < 2.0 ? 2.0 : r) {}
-        double radius() const { return m_radius; }
-        double calc_weight(double x) const
-        {
-           if(x == 0.0) return 1.0;
-           if(x > m_radius) return 0.0;
-           x *= pi;
-           double xr = x / m_radius;
-           return (sin(x) / x) * (0.42 + 0.5*cos(xr) + 0.08*cos(2*xr));
-        }
-    private:
-        double m_radius;
-    };
-
-    //------------------------------------------------image_filter_sinc36
-    class image_filter_sinc36 : public image_filter_sinc
-    { public: image_filter_sinc36() : image_filter_sinc(3.0){} };
-
-    //------------------------------------------------image_filter_sinc64
-    class image_filter_sinc64 : public image_filter_sinc
-    { public: image_filter_sinc64() : image_filter_sinc(4.0){} };
-
-    //-----------------------------------------------image_filter_sinc100
-    class image_filter_sinc100 : public image_filter_sinc
-    { public: image_filter_sinc100() : image_filter_sinc(5.0){} };
-
-    //-----------------------------------------------image_filter_sinc144
-    class image_filter_sinc144 : public image_filter_sinc
-    { public: image_filter_sinc144() : image_filter_sinc(6.0){} };
-
-    //-----------------------------------------------image_filter_sinc196
-    class image_filter_sinc196 : public image_filter_sinc
-    { public: image_filter_sinc196() : image_filter_sinc(7.0){} };
-
-    //-----------------------------------------------image_filter_sinc256
-    class image_filter_sinc256 : public image_filter_sinc
-    { public: image_filter_sinc256() : image_filter_sinc(8.0){} };
-
-    //---------------------------------------------image_filter_lanczos36
-    class image_filter_lanczos36 : public image_filter_lanczos
-    { public: image_filter_lanczos36() : image_filter_lanczos(3.0){} };
-
-    //---------------------------------------------image_filter_lanczos64
-    class image_filter_lanczos64 : public image_filter_lanczos
-    { public: image_filter_lanczos64() : image_filter_lanczos(4.0){} };
-
-    //--------------------------------------------image_filter_lanczos100
-    class image_filter_lanczos100 : public image_filter_lanczos
-    { public: image_filter_lanczos100() : image_filter_lanczos(5.0){} };
-
-    //--------------------------------------------image_filter_lanczos144
-    class image_filter_lanczos144 : public image_filter_lanczos
-    { public: image_filter_lanczos144() : image_filter_lanczos(6.0){} };
-
-    //--------------------------------------------image_filter_lanczos196
-    class image_filter_lanczos196 : public image_filter_lanczos
-    { public: image_filter_lanczos196() : image_filter_lanczos(7.0){} };
-
-    //--------------------------------------------image_filter_lanczos256
-    class image_filter_lanczos256 : public image_filter_lanczos
-    { public: image_filter_lanczos256() : image_filter_lanczos(8.0){} };
-
-    //--------------------------------------------image_filter_blackman36
-    class image_filter_blackman36 : public image_filter_blackman
-    { public: image_filter_blackman36() : image_filter_blackman(3.0){} };
-
-    //--------------------------------------------image_filter_blackman64
-    class image_filter_blackman64 : public image_filter_blackman
-    { public: image_filter_blackman64() : image_filter_blackman(4.0){} };
-
-    //-------------------------------------------image_filter_blackman100
-    class image_filter_blackman100 : public image_filter_blackman
-    { public: image_filter_blackman100() : image_filter_blackman(5.0){} };
-
-    //-------------------------------------------image_filter_blackman144
-    class image_filter_blackman144 : public image_filter_blackman
-    { public: image_filter_blackman144() : image_filter_blackman(6.0){} };
-
-    //-------------------------------------------image_filter_blackman196
-    class image_filter_blackman196 : public image_filter_blackman
-    { public: image_filter_blackman196() : image_filter_blackman(7.0){} };
-
-    //-------------------------------------------image_filter_blackman256
-    class image_filter_blackman256 : public image_filter_blackman
-    { public: image_filter_blackman256() : image_filter_blackman(8.0){} };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_line_aa_basics.h b/xs/src/agg/agg_line_aa_basics.h
deleted file mode 100644
index c5acb18e7..000000000
--- a/xs/src/agg/agg_line_aa_basics.h
+++ /dev/null
@@ -1,189 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_LINE_AA_BASICS_INCLUDED
-#define AGG_LINE_AA_BASICS_INCLUDED
-
-#include <stdlib.h>
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    // See Implementation agg_line_aa_basics.cpp 
-
-    //-------------------------------------------------------------------------
-    enum line_subpixel_scale_e
-    {
-        line_subpixel_shift = 8,                          //----line_subpixel_shift
-        line_subpixel_scale  = 1 << line_subpixel_shift,  //----line_subpixel_scale
-        line_subpixel_mask  = line_subpixel_scale - 1,    //----line_subpixel_mask
-        line_max_coord      = (1 << 28) - 1,              //----line_max_coord
-        line_max_length = 1 << (line_subpixel_shift + 10) //----line_max_length
-    };
-
-    //-------------------------------------------------------------------------
-    enum line_mr_subpixel_scale_e
-    {
-        line_mr_subpixel_shift = 4,                           //----line_mr_subpixel_shift
-        line_mr_subpixel_scale = 1 << line_mr_subpixel_shift, //----line_mr_subpixel_scale 
-        line_mr_subpixel_mask  = line_mr_subpixel_scale - 1   //----line_mr_subpixel_mask 
-    };
-
-    //------------------------------------------------------------------line_mr
-    AGG_INLINE int line_mr(int x) 
-    { 
-        return x >> (line_subpixel_shift - line_mr_subpixel_shift); 
-    }
-
-    //-------------------------------------------------------------------line_hr
-    AGG_INLINE int line_hr(int x) 
-    { 
-        return x << (line_subpixel_shift - line_mr_subpixel_shift); 
-    }
-
-    //---------------------------------------------------------------line_dbl_hr
-    AGG_INLINE int line_dbl_hr(int x) 
-    { 
-        return x << line_subpixel_shift;
-    }
-
-    //---------------------------------------------------------------line_coord
-    struct line_coord
-    {
-        AGG_INLINE static int conv(double x)
-        {
-            return iround(x * line_subpixel_scale);
-        }
-    };
-
-    //-----------------------------------------------------------line_coord_sat
-    struct line_coord_sat
-    {
-        AGG_INLINE static int conv(double x)
-        {
-            return saturation<line_max_coord>::iround(x * line_subpixel_scale);
-        }
-    };
-
-    //==========================================================line_parameters
-    struct line_parameters
-    {
-        //---------------------------------------------------------------------
-        line_parameters() {}
-        line_parameters(int x1_, int y1_, int x2_, int y2_, int len_) :
-            x1(x1_), y1(y1_), x2(x2_), y2(y2_), 
-            dx(abs(x2_ - x1_)),
-            dy(abs(y2_ - y1_)),
-            sx((x2_ > x1_) ? 1 : -1),
-            sy((y2_ > y1_) ? 1 : -1),
-            vertical(dy >= dx),
-            inc(vertical ? sy : sx),
-            len(len_),
-            octant((sy & 4) | (sx & 2) | int(vertical))
-        {
-        }
-
-        //---------------------------------------------------------------------
-        unsigned orthogonal_quadrant() const { return s_orthogonal_quadrant[octant]; }
-        unsigned diagonal_quadrant()   const { return s_diagonal_quadrant[octant];   }
-
-        //---------------------------------------------------------------------
-        bool same_orthogonal_quadrant(const line_parameters& lp) const
-        {
-            return s_orthogonal_quadrant[octant] == s_orthogonal_quadrant[lp.octant];
-        }
-
-        //---------------------------------------------------------------------
-        bool same_diagonal_quadrant(const line_parameters& lp) const
-        {
-            return s_diagonal_quadrant[octant] == s_diagonal_quadrant[lp.octant];
-        }
-
-        //---------------------------------------------------------------------
-        void divide(line_parameters& lp1, line_parameters& lp2) const
-        {
-            int xmid = (x1 + x2) >> 1;
-            int ymid = (y1 + y2) >> 1;
-            int len2 = len >> 1;
-
-            lp1 = *this;
-            lp2 = *this;
-
-            lp1.x2  = xmid;
-            lp1.y2  = ymid;
-            lp1.len = len2;
-            lp1.dx  = abs(lp1.x2 - lp1.x1);
-            lp1.dy  = abs(lp1.y2 - lp1.y1);
-
-            lp2.x1  = xmid;
-            lp2.y1  = ymid;
-            lp2.len = len2;
-            lp2.dx  = abs(lp2.x2 - lp2.x1);
-            lp2.dy  = abs(lp2.y2 - lp2.y1);
-        }
-        
-        //---------------------------------------------------------------------
-        int x1, y1, x2, y2, dx, dy, sx, sy;
-        bool vertical;
-        int inc;
-        int len;
-        int octant;
-
-        //---------------------------------------------------------------------
-        static const int8u s_orthogonal_quadrant[8];
-        static const int8u s_diagonal_quadrant[8];
-    };
-
-
-
-    // See Implementation agg_line_aa_basics.cpp 
-
-    //----------------------------------------------------------------bisectrix
-    void bisectrix(const line_parameters& l1, 
-                   const line_parameters& l2, 
-                   int* x, int* y);
-
-
-    //-------------------------------------------fix_degenerate_bisectrix_start
-    void inline fix_degenerate_bisectrix_start(const line_parameters& lp, 
-                                               int* x, int* y)
-    {
-        int d = iround((double(*x - lp.x2) * double(lp.y2 - lp.y1) - 
-                        double(*y - lp.y2) * double(lp.x2 - lp.x1)) / lp.len);
-        if(d < line_subpixel_scale/2)
-        {
-            *x = lp.x1 + (lp.y2 - lp.y1);
-            *y = lp.y1 - (lp.x2 - lp.x1);
-        }
-    }
-
-
-    //---------------------------------------------fix_degenerate_bisectrix_end
-    void inline fix_degenerate_bisectrix_end(const line_parameters& lp, 
-                                             int* x, int* y)
-    {
-        int d = iround((double(*x - lp.x2) * double(lp.y2 - lp.y1) - 
-                        double(*y - lp.y2) * double(lp.x2 - lp.x1)) / lp.len);
-        if(d < line_subpixel_scale/2)
-        {
-            *x = lp.x2 + (lp.y2 - lp.y1);
-            *y = lp.y2 - (lp.x2 - lp.x1);
-        }
-    }
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_math_stroke.h b/xs/src/agg/agg_math_stroke.h
deleted file mode 100644
index 4806dcd4b..000000000
--- a/xs/src/agg/agg_math_stroke.h
+++ /dev/null
@@ -1,526 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Stroke math
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_STROKE_MATH_INCLUDED
-#define AGG_STROKE_MATH_INCLUDED
-
-#include "agg_math.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-    //-------------------------------------------------------------line_cap_e
-    enum line_cap_e
-    {
-        butt_cap,
-        square_cap,
-        round_cap
-    };
-
-    //------------------------------------------------------------line_join_e
-    enum line_join_e
-    {
-        miter_join         = 0,
-        miter_join_revert  = 1,
-        round_join         = 2,
-        bevel_join         = 3,
-        miter_join_round   = 4
-    };
-
-
-    //-----------------------------------------------------------inner_join_e
-    enum inner_join_e
-    {
-        inner_bevel,
-        inner_miter,
-        inner_jag,
-        inner_round
-    };
-
-    //------------------------------------------------------------math_stroke
-    template<class VertexConsumer> class math_stroke
-    {
-    public:
-        typedef typename VertexConsumer::value_type coord_type;
-
-        math_stroke();
-
-        void line_cap(line_cap_e lc)     { m_line_cap = lc; }
-        void line_join(line_join_e lj)   { m_line_join = lj; }
-        void inner_join(inner_join_e ij) { m_inner_join = ij; }
-
-        line_cap_e   line_cap()   const { return m_line_cap; }
-        line_join_e  line_join()  const { return m_line_join; }
-        inner_join_e inner_join() const { return m_inner_join; }
-
-        void width(double w);
-        void miter_limit(double ml) { m_miter_limit = ml; }
-        void miter_limit_theta(double t);
-        void inner_miter_limit(double ml) { m_inner_miter_limit = ml; }
-        void approximation_scale(double as) { m_approx_scale = as; }
-
-        double width() const { return m_width * 2.0; }
-        double miter_limit() const { return m_miter_limit; }
-        double inner_miter_limit() const { return m_inner_miter_limit; }
-        double approximation_scale() const { return m_approx_scale; }
-
-        void calc_cap(VertexConsumer& vc,
-                      const vertex_dist& v0, 
-                      const vertex_dist& v1, 
-                      double len);
-
-        void calc_join(VertexConsumer& vc,
-                       const vertex_dist& v0, 
-                       const vertex_dist& v1, 
-                       const vertex_dist& v2,
-                       double len1, 
-                       double len2);
-
-    private:
-        AGG_INLINE void add_vertex(VertexConsumer& vc, double x, double y)
-        {
-            vc.add(coord_type(x, y));
-        }
-
-        void calc_arc(VertexConsumer& vc,
-                      double x,   double y, 
-                      double dx1, double dy1, 
-                      double dx2, double dy2);
-
-        void calc_miter(VertexConsumer& vc,
-                        const vertex_dist& v0, 
-                        const vertex_dist& v1, 
-                        const vertex_dist& v2,
-                        double dx1, double dy1, 
-                        double dx2, double dy2,
-                        line_join_e lj,
-                        double mlimit,
-                        double dbevel);
-
-        double       m_width;
-        double       m_width_abs;
-        double       m_width_eps;
-        int          m_width_sign;
-        double       m_miter_limit;
-        double       m_inner_miter_limit;
-        double       m_approx_scale;
-        line_cap_e   m_line_cap;
-        line_join_e  m_line_join;
-        inner_join_e m_inner_join;
-    };
-
-    //-----------------------------------------------------------------------
-    template<class VC> math_stroke<VC>::math_stroke() :
-        m_width(0.5),
-        m_width_abs(0.5),
-        m_width_eps(0.5/1024.0),
-        m_width_sign(1),
-        m_miter_limit(4.0),
-        m_inner_miter_limit(1.01),
-        m_approx_scale(1.0),
-        m_line_cap(butt_cap),
-        m_line_join(miter_join),
-        m_inner_join(inner_miter)
-    {
-    }
-
-    //-----------------------------------------------------------------------
-    template<class VC> void math_stroke<VC>::width(double w)
-    { 
-        m_width = w * 0.5; 
-        if(m_width < 0)
-        {
-            m_width_abs  = -m_width;
-            m_width_sign = -1;
-        }
-        else
-        {
-            m_width_abs  = m_width;
-            m_width_sign = 1;
-        }
-        m_width_eps = m_width / 1024.0;
-    }
-
-    //-----------------------------------------------------------------------
-    template<class VC> void math_stroke<VC>::miter_limit_theta(double t)
-    { 
-        m_miter_limit = 1.0 / sin(t * 0.5) ;
-    }
-
-    //-----------------------------------------------------------------------
-    template<class VC> 
-    void math_stroke<VC>::calc_arc(VC& vc,
-                                   double x,   double y, 
-                                   double dx1, double dy1, 
-                                   double dx2, double dy2)
-    {
-        double a1 = atan2(dy1 * m_width_sign, dx1 * m_width_sign);
-        double a2 = atan2(dy2 * m_width_sign, dx2 * m_width_sign);
-        double da = a1 - a2;
-        int i, n;
-
-        da = acos(m_width_abs / (m_width_abs + 0.125 / m_approx_scale)) * 2;
-
-        add_vertex(vc, x + dx1, y + dy1);
-        if(m_width_sign > 0)
-        {
-            if(a1 > a2) a2 += 2 * pi;
-            n = int((a2 - a1) / da);
-            da = (a2 - a1) / (n + 1);
-            a1 += da;
-            for(i = 0; i < n; i++)
-            {
-                add_vertex(vc, x + cos(a1) * m_width, y + sin(a1) * m_width);
-                a1 += da;
-            }
-        }
-        else
-        {
-            if(a1 < a2) a2 -= 2 * pi;
-            n = int((a1 - a2) / da);
-            da = (a1 - a2) / (n + 1);
-            a1 -= da;
-            for(i = 0; i < n; i++)
-            {
-                add_vertex(vc, x + cos(a1) * m_width, y + sin(a1) * m_width);
-                a1 -= da;
-            }
-        }
-        add_vertex(vc, x + dx2, y + dy2);
-    }
-
-    //-----------------------------------------------------------------------
-    template<class VC> 
-    void math_stroke<VC>::calc_miter(VC& vc,
-                                     const vertex_dist& v0, 
-                                     const vertex_dist& v1, 
-                                     const vertex_dist& v2,
-                                     double dx1, double dy1, 
-                                     double dx2, double dy2,
-                                     line_join_e lj,
-                                     double mlimit,
-                                     double dbevel)
-    {
-        double xi  = v1.x;
-        double yi  = v1.y;
-        double di  = 1;
-        double lim = m_width_abs * mlimit;
-        bool miter_limit_exceeded = true; // Assume the worst
-        bool intersection_failed  = true; // Assume the worst
-
-        if(calc_intersection(v0.x + dx1, v0.y - dy1,
-                             v1.x + dx1, v1.y - dy1,
-                             v1.x + dx2, v1.y - dy2,
-                             v2.x + dx2, v2.y - dy2,
-                             &xi, &yi))
-        {
-            // Calculation of the intersection succeeded
-            //---------------------
-            di = calc_distance(v1.x, v1.y, xi, yi);
-            if(di <= lim)
-            {
-                // Inside the miter limit
-                //---------------------
-                add_vertex(vc, xi, yi);
-                miter_limit_exceeded = false;
-            }
-            intersection_failed = false;
-        }
-        else
-        {
-            // Calculation of the intersection failed, most probably
-            // the three points lie one straight line. 
-            // First check if v0 and v2 lie on the opposite sides of vector: 
-            // (v1.x, v1.y) -> (v1.x+dx1, v1.y-dy1), that is, the perpendicular
-            // to the line determined by vertices v0 and v1.
-            // This condition determines whether the next line segments continues
-            // the previous one or goes back.
-            //----------------
-            double x2 = v1.x + dx1;
-            double y2 = v1.y - dy1;
-            if((cross_product(v0.x, v0.y, v1.x, v1.y, x2, y2) < 0.0) == 
-               (cross_product(v1.x, v1.y, v2.x, v2.y, x2, y2) < 0.0))
-            {
-                // This case means that the next segment continues 
-                // the previous one (straight line)
-                //-----------------
-                add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                miter_limit_exceeded = false;
-            }
-        }
-
-        if(miter_limit_exceeded)
-        {
-            // Miter limit exceeded
-            //------------------------
-            switch(lj)
-            {
-            case miter_join_revert:
-                // For the compatibility with SVG, PDF, etc, 
-                // we use a simple bevel join instead of
-                // "smart" bevel
-                //-------------------
-                add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                add_vertex(vc, v1.x + dx2, v1.y - dy2);
-                break;
-
-            case miter_join_round:
-                calc_arc(vc, v1.x, v1.y, dx1, -dy1, dx2, -dy2);
-                break;
-
-            default:
-                // If no miter-revert, calculate new dx1, dy1, dx2, dy2
-                //----------------
-                if(intersection_failed)
-                {
-                    mlimit *= m_width_sign;
-                    add_vertex(vc, v1.x + dx1 + dy1 * mlimit, 
-                                   v1.y - dy1 + dx1 * mlimit);
-                    add_vertex(vc, v1.x + dx2 - dy2 * mlimit, 
-                                   v1.y - dy2 - dx2 * mlimit);
-                }
-                else
-                {
-                    double x1 = v1.x + dx1;
-                    double y1 = v1.y - dy1;
-                    double x2 = v1.x + dx2;
-                    double y2 = v1.y - dy2;
-                    di = (lim - dbevel) / (di - dbevel);
-                    add_vertex(vc, x1 + (xi - x1) * di, 
-                                   y1 + (yi - y1) * di);
-                    add_vertex(vc, x2 + (xi - x2) * di, 
-                                   y2 + (yi - y2) * di);
-                }
-                break;
-            }
-        }
-    }
-
-    //--------------------------------------------------------stroke_calc_cap
-    template<class VC> 
-    void math_stroke<VC>::calc_cap(VC& vc,
-                                   const vertex_dist& v0, 
-                                   const vertex_dist& v1, 
-                                   double len)
-    {
-        vc.remove_all();
-
-        double dx1 = (v1.y - v0.y) / len;
-        double dy1 = (v1.x - v0.x) / len;
-        double dx2 = 0;
-        double dy2 = 0;
-
-        dx1 *= m_width;
-        dy1 *= m_width;
-
-        if(m_line_cap != round_cap)
-        {
-            if(m_line_cap == square_cap)
-            {
-                dx2 = dy1 * m_width_sign;
-                dy2 = dx1 * m_width_sign;
-            }
-            add_vertex(vc, v0.x - dx1 - dx2, v0.y + dy1 - dy2);
-            add_vertex(vc, v0.x + dx1 - dx2, v0.y - dy1 - dy2);
-        }
-        else
-        {
-            double da = acos(m_width_abs / (m_width_abs + 0.125 / m_approx_scale)) * 2;
-            double a1;
-            int i;
-            int n = int(pi / da);
-
-            da = pi / (n + 1);
-            add_vertex(vc, v0.x - dx1, v0.y + dy1);
-            if(m_width_sign > 0)
-            {
-                a1 = atan2(dy1, -dx1);
-                a1 += da;
-                for(i = 0; i < n; i++)
-                {
-                    add_vertex(vc, v0.x + cos(a1) * m_width, 
-                                   v0.y + sin(a1) * m_width);
-                    a1 += da;
-                }
-            }
-            else
-            {
-                a1 = atan2(-dy1, dx1);
-                a1 -= da;
-                for(i = 0; i < n; i++)
-                {
-                    add_vertex(vc, v0.x + cos(a1) * m_width, 
-                                   v0.y + sin(a1) * m_width);
-                    a1 -= da;
-                }
-            }
-            add_vertex(vc, v0.x + dx1, v0.y - dy1);
-        }
-    }
-
-    //-----------------------------------------------------------------------
-    template<class VC> 
-    void math_stroke<VC>::calc_join(VC& vc,
-                                    const vertex_dist& v0, 
-                                    const vertex_dist& v1, 
-                                    const vertex_dist& v2,
-                                    double len1, 
-                                    double len2)
-    {
-        double dx1 = m_width * (v1.y - v0.y) / len1;
-        double dy1 = m_width * (v1.x - v0.x) / len1;
-        double dx2 = m_width * (v2.y - v1.y) / len2;
-        double dy2 = m_width * (v2.x - v1.x) / len2;
-
-        vc.remove_all();
-
-        double cp = cross_product(v0.x, v0.y, v1.x, v1.y, v2.x, v2.y);
-        if(cp != 0 && (cp > 0) == (m_width > 0))
-        {
-            // Inner join
-            //---------------
-            double limit = ((len1 < len2) ? len1 : len2) / m_width_abs;
-            if(limit < m_inner_miter_limit)
-            {
-                limit = m_inner_miter_limit;
-            }
-
-            switch(m_inner_join)
-            {
-            default: // inner_bevel
-                add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                add_vertex(vc, v1.x + dx2, v1.y - dy2);
-                break;
-
-            case inner_miter:
-                calc_miter(vc,
-                           v0, v1, v2, dx1, dy1, dx2, dy2, 
-                           miter_join_revert, 
-                           limit, 0);
-                break;
-
-            case inner_jag:
-            case inner_round:
-                cp = (dx1-dx2) * (dx1-dx2) + (dy1-dy2) * (dy1-dy2);
-                if(cp < len1 * len1 && cp < len2 * len2)
-                {
-                    calc_miter(vc,
-                               v0, v1, v2, dx1, dy1, dx2, dy2, 
-                               miter_join_revert, 
-                               limit, 0);
-                }
-                else
-                {
-                    if(m_inner_join == inner_jag)
-                    {
-                        add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                        add_vertex(vc, v1.x,       v1.y      );
-                        add_vertex(vc, v1.x + dx2, v1.y - dy2);
-                    }
-                    else
-                    {
-                        add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                        add_vertex(vc, v1.x,       v1.y      );
-                        calc_arc(vc, v1.x, v1.y, dx2, -dy2, dx1, -dy1);
-                        add_vertex(vc, v1.x,       v1.y      );
-                        add_vertex(vc, v1.x + dx2, v1.y - dy2);
-                    }
-                }
-                break;
-            }
-        }
-        else
-        {
-            // Outer join
-            //---------------
-
-            // Calculate the distance between v1 and 
-            // the central point of the bevel line segment
-            //---------------
-            double dx = (dx1 + dx2) / 2;
-            double dy = (dy1 + dy2) / 2;
-            double dbevel = sqrt(dx * dx + dy * dy);
-
-            if(m_line_join == round_join || m_line_join == bevel_join)
-            {
-                // This is an optimization that reduces the number of points 
-                // in cases of almost collinear segments. If there's no
-                // visible difference between bevel and miter joins we'd rather
-                // use miter join because it adds only one point instead of two. 
-                //
-                // Here we calculate the middle point between the bevel points 
-                // and then, the distance between v1 and this middle point. 
-                // At outer joins this distance always less than stroke width, 
-                // because it's actually the height of an isosceles triangle of
-                // v1 and its two bevel points. If the difference between this
-                // width and this value is small (no visible bevel) we can 
-                // add just one point. 
-                //
-                // The constant in the expression makes the result approximately 
-                // the same as in round joins and caps. You can safely comment 
-                // out this entire "if".
-                //-------------------
-                if(m_approx_scale * (m_width_abs - dbevel) < m_width_eps)
-                {
-                    if(calc_intersection(v0.x + dx1, v0.y - dy1,
-                                         v1.x + dx1, v1.y - dy1,
-                                         v1.x + dx2, v1.y - dy2,
-                                         v2.x + dx2, v2.y - dy2,
-                                         &dx, &dy))
-                    {
-                        add_vertex(vc, dx, dy);
-                    }
-                    else
-                    {
-                        add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                    }
-                    return;
-                }
-            }
-
-            switch(m_line_join)
-            {
-            case miter_join:
-            case miter_join_revert:
-            case miter_join_round:
-                calc_miter(vc, 
-                           v0, v1, v2, dx1, dy1, dx2, dy2, 
-                           m_line_join, 
-                           m_miter_limit,
-                           dbevel);
-                break;
-
-            case round_join:
-                calc_arc(vc, v1.x, v1.y, dx1, -dy1, dx2, -dy2);
-                break;
-
-            default: // Bevel join
-                add_vertex(vc, v1.x + dx1, v1.y - dy1);
-                add_vertex(vc, v1.x + dx2, v1.y - dy2);
-                break;
-            }
-        }
-    }
-
-
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_path_length.h b/xs/src/agg/agg_path_length.h
deleted file mode 100644
index 740ba31df..000000000
--- a/xs/src/agg/agg_path_length.h
+++ /dev/null
@@ -1,65 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_PATH_LENGTH_INCLUDED
-#define AGG_PATH_LENGTH_INCLUDED
-
-#include "agg_math.h"
-
-namespace agg
-{
-    template<class VertexSource> 
-    double path_length(VertexSource& vs, unsigned path_id = 0)
-    {
-        double len = 0.0;
-        double start_x = 0.0;
-        double start_y = 0.0;
-        double x1 = 0.0;
-        double y1 = 0.0;
-        double x2 = 0.0;
-        double y2 = 0.0;
-        bool first = true;
-
-        unsigned cmd;
-        vs.rewind(path_id);
-        while(!is_stop(cmd = vs.vertex(&x2, &y2)))
-        {
-            if(is_vertex(cmd))
-            {
-                if(first || is_move_to(cmd))
-                {
-                    start_x = x2;
-                    start_y = y2;
-                }
-                else
-                {
-                    len += calc_distance(x1, y1, x2, y2);
-                }
-                x1 = x2;
-                y1 = y2;
-                first = false;
-            }
-            else
-            {
-                if(is_close(cmd) && !first)
-                {
-                    len += calc_distance(x1, y1, start_x, start_y);
-                }
-            }
-        }
-        return len;
-    }
-}
-
-#endif
diff --git a/xs/src/agg/agg_path_storage_integer.h b/xs/src/agg/agg_path_storage_integer.h
deleted file mode 100644
index 7c4835599..000000000
--- a/xs/src/agg/agg_path_storage_integer.h
+++ /dev/null
@@ -1,295 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_PATH_STORAGE_INTEGER_INCLUDED
-#define AGG_PATH_STORAGE_INTEGER_INCLUDED
-
-#include <string.h>
-#include "agg_array.h"
-
-namespace agg
-{
-    //---------------------------------------------------------vertex_integer
-    template<class T, unsigned CoordShift=6> struct vertex_integer
-    {
-        enum path_cmd
-        {
-            cmd_move_to = 0,
-            cmd_line_to = 1,
-            cmd_curve3  = 2,
-            cmd_curve4  = 3
-        };
-
-        enum coord_scale_e
-        {
-            coord_shift = CoordShift,
-            coord_scale  = 1 << coord_shift
-        };
-
-        T x,y;
-        vertex_integer() {}
-        vertex_integer(T x_, T y_, unsigned flag) :
-            x(((x_ << 1) & ~1) | (flag &  1)),
-            y(((y_ << 1) & ~1) | (flag >> 1)) {}
-
-        unsigned vertex(double* x_, double* y_, 
-                        double dx=0, double dy=0,
-                        double scale=1.0) const
-        {
-            *x_ = dx + (double(x >> 1) / coord_scale) * scale;
-            *y_ = dy + (double(y >> 1) / coord_scale) * scale;
-            switch(((y & 1) << 1) | (x & 1))
-            {
-                case cmd_move_to: return path_cmd_move_to;
-                case cmd_line_to: return path_cmd_line_to;
-                case cmd_curve3:  return path_cmd_curve3;
-                case cmd_curve4:  return path_cmd_curve4;
-            }
-            return path_cmd_stop;
-        }
-    };
-
-
-    //---------------------------------------------------path_storage_integer
-    template<class T, unsigned CoordShift=6> class path_storage_integer
-    {
-    public:
-        typedef T value_type;
-        typedef vertex_integer<T, CoordShift> vertex_integer_type;
-
-        //--------------------------------------------------------------------
-        path_storage_integer() : m_storage(), m_vertex_idx(0), m_closed(true) {}
-
-        //--------------------------------------------------------------------
-        void remove_all() { m_storage.remove_all(); }
-
-        //--------------------------------------------------------------------
-        void move_to(T x, T y)
-        {
-            m_storage.add(vertex_integer_type(x, y, vertex_integer_type::cmd_move_to));
-        }
-
-        //--------------------------------------------------------------------
-        void line_to(T x, T y)
-        {
-            m_storage.add(vertex_integer_type(x, y, vertex_integer_type::cmd_line_to));
-        }
-
-        //--------------------------------------------------------------------
-        void curve3(T x_ctrl,  T y_ctrl, 
-                    T x_to,    T y_to)
-        {
-            m_storage.add(vertex_integer_type(x_ctrl, y_ctrl, vertex_integer_type::cmd_curve3));
-            m_storage.add(vertex_integer_type(x_to,   y_to,   vertex_integer_type::cmd_curve3));
-        }
-
-        //--------------------------------------------------------------------
-        void curve4(T x_ctrl1, T y_ctrl1, 
-                    T x_ctrl2, T y_ctrl2, 
-                    T x_to,    T y_to)
-        {
-            m_storage.add(vertex_integer_type(x_ctrl1, y_ctrl1, vertex_integer_type::cmd_curve4));
-            m_storage.add(vertex_integer_type(x_ctrl2, y_ctrl2, vertex_integer_type::cmd_curve4));
-            m_storage.add(vertex_integer_type(x_to,    y_to,    vertex_integer_type::cmd_curve4));
-        }
-
-        //--------------------------------------------------------------------
-        void close_polygon() {}
-
-        //--------------------------------------------------------------------
-        unsigned size() const { return m_storage.size(); }
-        unsigned vertex(unsigned idx, double* x, double* y) const
-        {
-            return m_storage[idx].vertex(x, y);
-        }
-
-        //--------------------------------------------------------------------
-        unsigned byte_size() const { return m_storage.size() * sizeof(vertex_integer_type); }
-        void serialize(int8u* ptr) const
-        {
-            unsigned i;
-            for(i = 0; i < m_storage.size(); i++)
-            {
-                memcpy(ptr, &m_storage[i], sizeof(vertex_integer_type));
-                ptr += sizeof(vertex_integer_type);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void rewind(unsigned) 
-        { 
-            m_vertex_idx = 0; 
-            m_closed = true;
-        }
-
-        //--------------------------------------------------------------------
-        unsigned vertex(double* x, double* y)
-        {
-            if(m_storage.size() < 2 || m_vertex_idx > m_storage.size()) 
-            {
-                *x = 0;
-                *y = 0;
-                return path_cmd_stop;
-            }
-            if(m_vertex_idx == m_storage.size())
-            {
-                *x = 0;
-                *y = 0;
-                ++m_vertex_idx;
-                return path_cmd_end_poly | path_flags_close;
-            }
-            unsigned cmd = m_storage[m_vertex_idx].vertex(x, y);
-            if(is_move_to(cmd) && !m_closed)
-            {
-                *x = 0;
-                *y = 0;
-                m_closed = true;
-                return path_cmd_end_poly | path_flags_close;
-            }
-            m_closed = false;
-            ++m_vertex_idx;
-            return cmd;
-        }
-
-        //--------------------------------------------------------------------
-        rect_d bounding_rect() const
-        {
-            rect_d bounds(1e100, 1e100, -1e100, -1e100);
-            if(m_storage.size() == 0)
-            {
-                bounds.x1 = bounds.y1 = bounds.x2 = bounds.y2 = 0.0;
-            }
-            else
-            {
-                unsigned i;
-                for(i = 0; i < m_storage.size(); i++)
-                {
-                    double x, y;
-                    m_storage[i].vertex(&x, &y);
-                    if(x < bounds.x1) bounds.x1 = x;
-                    if(y < bounds.y1) bounds.y1 = y;
-                    if(x > bounds.x2) bounds.x2 = x;
-                    if(y > bounds.y2) bounds.y2 = y;
-                }
-            }
-            return bounds;
-        }
-
-    private:
-        pod_bvector<vertex_integer_type, 6> m_storage;
-        unsigned                            m_vertex_idx;
-        bool                                m_closed;
-    };
-
-
-
-
-    //-----------------------------------------serialized_integer_path_adaptor
-    template<class T, unsigned CoordShift=6> class serialized_integer_path_adaptor
-    {
-    public:
-        typedef vertex_integer<T, CoordShift> vertex_integer_type;
-
-        //--------------------------------------------------------------------
-        serialized_integer_path_adaptor() :
-            m_data(0),
-            m_end(0),
-            m_ptr(0),
-            m_dx(0.0),
-            m_dy(0.0),
-            m_scale(1.0),
-            m_vertices(0)
-        {}
-
-        //--------------------------------------------------------------------
-        serialized_integer_path_adaptor(const int8u* data, unsigned size,
-                                        double dx, double dy) :
-            m_data(data),
-            m_end(data + size),
-            m_ptr(data),
-            m_dx(dx),
-            m_dy(dy),
-            m_vertices(0)
-        {}
-
-        //--------------------------------------------------------------------
-        void init(const int8u* data, unsigned size, 
-                  double dx, double dy, double scale=1.0)
-        {
-            m_data     = data;
-            m_end      = data + size;
-            m_ptr      = data;
-            m_dx       = dx;
-            m_dy       = dy;
-            m_scale    = scale;
-            m_vertices = 0;
-        }
-
-
-        //--------------------------------------------------------------------
-        void rewind(unsigned) 
-        { 
-            m_ptr      = m_data; 
-            m_vertices = 0;
-        }
-
-        //--------------------------------------------------------------------
-        unsigned vertex(double* x, double* y)
-        {
-            if(m_data == 0 || m_ptr > m_end) 
-            {
-                *x = 0;
-                *y = 0;
-                return path_cmd_stop;
-            }
-
-            if(m_ptr == m_end)
-            {
-                *x = 0;
-                *y = 0;
-                m_ptr += sizeof(vertex_integer_type);
-                return path_cmd_end_poly | path_flags_close;
-            }
-
-            vertex_integer_type v;
-            memcpy(&v, m_ptr, sizeof(vertex_integer_type));
-            unsigned cmd = v.vertex(x, y, m_dx, m_dy, m_scale);
-            if(is_move_to(cmd) && m_vertices > 2)
-            {
-                *x = 0;
-                *y = 0;
-                m_vertices = 0;
-                return path_cmd_end_poly | path_flags_close;
-            }
-            ++m_vertices;
-            m_ptr += sizeof(vertex_integer_type);
-            return cmd;
-        }
-
-    private:
-        const int8u* m_data;
-        const int8u* m_end;
-        const int8u* m_ptr;
-        double       m_dx;
-        double       m_dy;
-        double       m_scale;
-        unsigned     m_vertices;
-    };
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_pattern_filters_rgba.h b/xs/src/agg/agg_pattern_filters_rgba.h
deleted file mode 100644
index c1d174cac..000000000
--- a/xs/src/agg/agg_pattern_filters_rgba.h
+++ /dev/null
@@ -1,123 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_PATTERN_FILTERS_RGBA8_INCLUDED
-#define AGG_PATTERN_FILTERS_RGBA8_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_line_aa_basics.h"
-#include "agg_color_rgba.h"
-
-
-namespace agg
-{
-
-    //=======================================================pattern_filter_nn
-    template<class ColorT> struct pattern_filter_nn
-    {
-        typedef ColorT color_type;
-        static unsigned dilation() { return 0; }
-
-        static void AGG_INLINE pixel_low_res(color_type const* const* buf, 
-                                             color_type* p, int x, int y)
-        {
-            *p = buf[y][x];
-        }
-
-        static void AGG_INLINE pixel_high_res(color_type const* const* buf, 
-                                              color_type* p, int x, int y)
-        {
-            *p = buf[y >> line_subpixel_shift]
-                    [x >> line_subpixel_shift];
-        }
-    };
-
-    typedef pattern_filter_nn<rgba8>  pattern_filter_nn_rgba8;
-    typedef pattern_filter_nn<rgba16> pattern_filter_nn_rgba16;
-
-
-    //===========================================pattern_filter_bilinear_rgba
-    template<class ColorT> struct pattern_filter_bilinear_rgba
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-
-
-        static unsigned dilation() { return 1; }
-
-        static AGG_INLINE void pixel_low_res(color_type const* const* buf, 
-                                             color_type* p, int x, int y)
-        {
-            *p = buf[y][x];
-        }
-
-        static AGG_INLINE void pixel_high_res(color_type const* const* buf, 
-                                              color_type* p, int x, int y)
-        {
-            calc_type r, g, b, a;
-            r = g = b = a = 0;
-
-            calc_type weight;
-            int x_lr = x >> line_subpixel_shift;
-            int y_lr = y >> line_subpixel_shift;
-
-            x &= line_subpixel_mask;
-            y &= line_subpixel_mask;
-            const color_type* ptr = buf[y_lr] + x_lr;
-
-            weight = (line_subpixel_scale - x) * 
-                     (line_subpixel_scale - y);
-            r += weight * ptr->r;
-            g += weight * ptr->g;
-            b += weight * ptr->b;
-            a += weight * ptr->a;
-
-            ++ptr;
-
-            weight = x * (line_subpixel_scale - y);
-            r += weight * ptr->r;
-            g += weight * ptr->g;
-            b += weight * ptr->b;
-            a += weight * ptr->a;
-
-            ptr = buf[y_lr + 1] + x_lr;
-
-            weight = (line_subpixel_scale - x) * y;
-            r += weight * ptr->r;
-            g += weight * ptr->g;
-            b += weight * ptr->b;
-            a += weight * ptr->a;
-
-            ++ptr;
-
-            weight = x * y;
-            r += weight * ptr->r;
-            g += weight * ptr->g;
-            b += weight * ptr->b;
-            a += weight * ptr->a;
-
-            p->r = (value_type)color_type::downshift(r, line_subpixel_shift * 2);
-            p->g = (value_type)color_type::downshift(g, line_subpixel_shift * 2);
-            p->b = (value_type)color_type::downshift(b, line_subpixel_shift * 2);
-            p->a = (value_type)color_type::downshift(a, line_subpixel_shift * 2);
-        }
-    };
-
-    typedef pattern_filter_bilinear_rgba<rgba8>  pattern_filter_bilinear_rgba8;
-    typedef pattern_filter_bilinear_rgba<rgba16> pattern_filter_bilinear_rgba16;
-    typedef pattern_filter_bilinear_rgba<rgba32> pattern_filter_bilinear_rgba32;
-}
-
-#endif
diff --git a/xs/src/agg/agg_pixfmt_amask_adaptor.h b/xs/src/agg/agg_pixfmt_amask_adaptor.h
deleted file mode 100644
index 568a74dac..000000000
--- a/xs/src/agg/agg_pixfmt_amask_adaptor.h
+++ /dev/null
@@ -1,240 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_PIXFMT_AMASK_ADAPTOR_INCLUDED
-#define AGG_PIXFMT_AMASK_ADAPTOR_INCLUDED
-
-
-#include <string.h>
-#include "agg_array.h"
-#include "agg_rendering_buffer.h"
-
-
-namespace agg
-{
-    //==================================================pixfmt_amask_adaptor
-    template<class PixFmt, class AlphaMask> class pixfmt_amask_adaptor
-    {
-    public:
-        typedef PixFmt pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::row_data row_data;
-        typedef AlphaMask amask_type;
-        typedef typename amask_type::cover_type cover_type;
-
-    private:
-        enum span_extra_tail_e { span_extra_tail = 256 };
-
-        void realloc_span(unsigned len)
-        {
-            if(len > m_span.size())
-            {
-                m_span.resize(len + span_extra_tail);
-            }
-        }
-
-        void init_span(unsigned len)
-        {
-            realloc_span(len);
-            memset(&m_span[0], amask_type::cover_full, len * sizeof(cover_type));
-        }
-
-        void init_span(unsigned len, const cover_type* covers)
-        {
-            realloc_span(len);
-            memcpy(&m_span[0], covers, len * sizeof(cover_type));
-        }
-
-
-    public:
-        pixfmt_amask_adaptor(pixfmt_type& pixf, amask_type& mask) :
-            m_pixf(&pixf), m_mask(&mask), m_span()
-        {}
-
-        void attach_pixfmt(pixfmt_type& pixf) { m_pixf = &pixf; }
-        void attach_alpha_mask(amask_type& mask) { m_mask = &mask; }
-
-        //--------------------------------------------------------------------
-        template<class PixFmt2>
-        bool attach_pixfmt(PixFmt2& pixf, int x1, int y1, int x2, int y2)
-        {
-            return m_pixf->attach(pixf, x1, y1, x2, y2);
-        }
-
-        //--------------------------------------------------------------------
-        unsigned width()  const { return m_pixf->width();  }
-        unsigned height() const { return m_pixf->height(); }
-
-        //--------------------------------------------------------------------
-        color_type pixel(int x, int y)
-        {
-            return m_pixf->pixel(x, y);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_pixel(int x, int y, const color_type& c)
-        {
-            m_pixf->blend_pixel(x, y, c, m_mask->pixel(x, y));
-        }
-
-        //--------------------------------------------------------------------
-        void blend_pixel(int x, int y, const color_type& c, cover_type cover)
-        {
-            m_pixf->blend_pixel(x, y, c, m_mask->combine_pixel(x, y, cover));
-        }
-
-        //--------------------------------------------------------------------
-        void copy_hline(int x, int y, 
-                        unsigned len, 
-                        const color_type& c)
-        {
-            realloc_span(len);
-            m_mask->fill_hspan(x, y, &m_span[0], len);
-            m_pixf->blend_solid_hspan(x, y, len, c, &m_span[0]);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_hline(int x, int y,
-                         unsigned len, 
-                         const color_type& c,
-                         cover_type)
-        {
-            init_span(len);
-            m_mask->combine_hspan(x, y, &m_span[0], len);
-            m_pixf->blend_solid_hspan(x, y, len, c, &m_span[0]);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_vline(int x, int y,
-                        unsigned len, 
-                        const color_type& c)
-        {
-            realloc_span(len);
-            m_mask->fill_vspan(x, y, &m_span[0], len);
-            m_pixf->blend_solid_vspan(x, y, len, c, &m_span[0]);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_vline(int x, int y,
-                         unsigned len, 
-                         const color_type& c,
-                         cover_type)
-        {
-            init_span(len);
-            m_mask->combine_vspan(x, y, &m_span[0], len);
-            m_pixf->blend_solid_vspan(x, y, len, c, &m_span[0]);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_from(const rendering_buffer& from, 
-                       int xdst, int ydst,
-                       int xsrc, int ysrc,
-                       unsigned len)
-        {
-            m_pixf->copy_from(from, xdst, ydst, xsrc, ysrc, len);
-        }
-
-
-        //--------------------------------------------------------------------
-        void blend_solid_hspan(int x, int y,
-                               unsigned len, 
-                               const color_type& c,
-                               const cover_type* covers)
-        {
-            init_span(len, covers);
-            m_mask->combine_hspan(x, y, &m_span[0], len);
-            m_pixf->blend_solid_hspan(x, y, len, c, &m_span[0]);
-        }
-
-
-        //--------------------------------------------------------------------
-        void blend_solid_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type& c,
-                               const cover_type* covers)
-        {
-            init_span(len, covers);
-            m_mask->combine_vspan(x, y, &m_span[0], len);
-            m_pixf->blend_solid_vspan(x, y, len, c, &m_span[0]);
-        }
-
-
-        //--------------------------------------------------------------------
-        void copy_color_hspan(int x, int y, unsigned len, const color_type* colors)
-        {
-            realloc_span(len);
-            m_mask->fill_hspan(x, y, &m_span[0], len);
-            m_pixf->blend_color_hspan(x, y, len, colors, &m_span[0], cover_full);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_color_vspan(int x, int y, unsigned len, const color_type* colors)
-        {
-            realloc_span(len);
-            m_mask->fill_vspan(x, y, &m_span[0], len);
-            m_pixf->blend_color_vspan(x, y, len, colors, &m_span[0], cover_full);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_hspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const cover_type* covers,
-                               cover_type cover = cover_full)
-        {
-            if(covers) 
-            {
-                init_span(len, covers);
-                m_mask->combine_hspan(x, y, &m_span[0], len);
-            }
-            else
-            {
-                realloc_span(len);
-                m_mask->fill_hspan(x, y, &m_span[0], len);
-            }
-            m_pixf->blend_color_hspan(x, y, len, colors, &m_span[0], cover);
-        }
-
-
-        //--------------------------------------------------------------------
-        void blend_color_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const cover_type* covers,
-                               cover_type cover = cover_full)
-        {
-            if(covers) 
-            {
-                init_span(len, covers);
-                m_mask->combine_vspan(x, y, &m_span[0], len);
-            }
-            else
-            {
-                realloc_span(len);
-                m_mask->fill_vspan(x, y, &m_span[0], len);
-            }
-            m_pixf->blend_color_vspan(x, y, len, colors, &m_span[0], cover);
-        }
-
-    private:
-        pixfmt_type*          m_pixf;
-        const amask_type*     m_mask;
-        pod_array<cover_type> m_span;
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_pixfmt_rgb_packed.h b/xs/src/agg/agg_pixfmt_rgb_packed.h
deleted file mode 100644
index 9152cf060..000000000
--- a/xs/src/agg/agg_pixfmt_rgb_packed.h
+++ /dev/null
@@ -1,1311 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_PIXFMT_RGB_PACKED_INCLUDED
-#define AGG_PIXFMT_RGB_PACKED_INCLUDED
-
-#include <string.h>
-#include "agg_basics.h"
-#include "agg_color_rgba.h"
-#include "agg_rendering_buffer.h"
-
-namespace agg
-{
-    //=========================================================blender_rgb555
-    struct blender_rgb555
-    {
-        typedef rgba8 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int16u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 7) & 0xF8;
-            calc_type g = (rgb >> 2) & 0xF8;
-            calc_type b = (rgb << 3) & 0xF8;
-            *p = (pixel_type)
-               (((((cr - r) * alpha + (r << 8)) >> 1)  & 0x7C00) |
-                ((((cg - g) * alpha + (g << 8)) >> 6)  & 0x03E0) |
-                 (((cb - b) * alpha + (b << 8)) >> 11) | 0x8000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xF8) << 7) | 
-                                ((g & 0xF8) << 2) | 
-                                 (b >> 3) | 0x8000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 7) & 0xF8, 
-                              (p >> 2) & 0xF8, 
-                              (p << 3) & 0xF8);
-        }
-    };
-
-
-    //=====================================================blender_rgb555_pre
-    struct blender_rgb555_pre
-    {
-        typedef rgba8 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int16u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned cover)
-        {
-            alpha = color_type::base_mask - alpha;
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 7) & 0xF8;
-            calc_type g = (rgb >> 2) & 0xF8;
-            calc_type b = (rgb << 3) & 0xF8;
-            *p = (pixel_type)
-               ((((r * alpha + cr * cover) >> 1)  & 0x7C00) |
-                (((g * alpha + cg * cover) >> 6)  & 0x03E0) |
-                 ((b * alpha + cb * cover) >> 11) | 0x8000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xF8) << 7) | 
-                                ((g & 0xF8) << 2) | 
-                                 (b >> 3) | 0x8000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 7) & 0xF8, 
-                              (p >> 2) & 0xF8, 
-                              (p << 3) & 0xF8);
-        }
-    };
-
-
-
-
-    //=====================================================blender_rgb555_gamma
-    template<class Gamma> class blender_rgb555_gamma
-    {
-    public:
-        typedef rgba8 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int16u pixel_type;
-        typedef Gamma gamma_type;
-
-        blender_rgb555_gamma() : m_gamma(0) {}
-        void gamma(const gamma_type& g) { m_gamma = &g; }
-
-        AGG_INLINE void blend_pix(pixel_type* p, 
-                                  unsigned cr, unsigned cg, unsigned cb,
-                                  unsigned alpha, 
-                                  unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = m_gamma->dir((rgb >> 7) & 0xF8);
-            calc_type g = m_gamma->dir((rgb >> 2) & 0xF8);
-            calc_type b = m_gamma->dir((rgb << 3) & 0xF8);
-            *p = (pixel_type)
-               (((m_gamma->inv(((m_gamma->dir(cr) - r) * alpha + (r << 8)) >> 8) << 7) & 0x7C00) |
-                ((m_gamma->inv(((m_gamma->dir(cg) - g) * alpha + (g << 8)) >> 8) << 2) & 0x03E0) |
-                 (m_gamma->inv(((m_gamma->dir(cb) - b) * alpha + (b << 8)) >> 8) >> 3) | 0x8000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xF8) << 7) | 
-                                ((g & 0xF8) << 2) | 
-                                 (b >> 3) | 0x8000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 7) & 0xF8, 
-                              (p >> 2) & 0xF8, 
-                              (p << 3) & 0xF8);
-        }
-
-    private:
-        const Gamma* m_gamma;
-    };
-
-
-
-
-
-    //=========================================================blender_rgb565
-    struct blender_rgb565
-    {
-        typedef rgba8 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int16u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 8) & 0xF8;
-            calc_type g = (rgb >> 3) & 0xFC;
-            calc_type b = (rgb << 3) & 0xF8;
-            *p = (pixel_type)
-               (((((cr - r) * alpha + (r << 8))     ) & 0xF800) |
-                ((((cg - g) * alpha + (g << 8)) >> 5) & 0x07E0) |
-                 (((cb - b) * alpha + (b << 8)) >> 11));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 8) & 0xF8, 
-                              (p >> 3) & 0xFC, 
-                              (p << 3) & 0xF8);
-        }
-    };
-
-
-
-    //=====================================================blender_rgb565_pre
-    struct blender_rgb565_pre
-    {
-        typedef rgba8 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int16u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned cover)
-        {
-            alpha = color_type::base_mask - alpha;
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 8) & 0xF8;
-            calc_type g = (rgb >> 3) & 0xFC;
-            calc_type b = (rgb << 3) & 0xF8;
-            *p = (pixel_type)
-               ((((r * alpha + cr * cover)      ) & 0xF800) |
-                (((g * alpha + cg * cover) >> 5 ) & 0x07E0) |
-                 ((b * alpha + cb * cover) >> 11));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 8) & 0xF8, 
-                              (p >> 3) & 0xFC, 
-                              (p << 3) & 0xF8);
-        }
-    };
-
-
-
-    //=====================================================blender_rgb565_gamma
-    template<class Gamma> class blender_rgb565_gamma
-    {
-    public:
-        typedef rgba8 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int16u pixel_type;
-        typedef Gamma gamma_type;
-
-        blender_rgb565_gamma() : m_gamma(0) {}
-        void gamma(const gamma_type& g) { m_gamma = &g; }
-
-        AGG_INLINE void blend_pix(pixel_type* p, 
-                                  unsigned cr, unsigned cg, unsigned cb,
-                                  unsigned alpha, 
-                                  unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = m_gamma->dir((rgb >> 8) & 0xF8);
-            calc_type g = m_gamma->dir((rgb >> 3) & 0xFC);
-            calc_type b = m_gamma->dir((rgb << 3) & 0xF8);
-            *p = (pixel_type)
-               (((m_gamma->inv(((m_gamma->dir(cr) - r) * alpha + (r << 8)) >> 8) << 8) & 0xF800) |
-                ((m_gamma->inv(((m_gamma->dir(cg) - g) * alpha + (g << 8)) >> 8) << 3) & 0x07E0) |
-                 (m_gamma->inv(((m_gamma->dir(cb) - b) * alpha + (b << 8)) >> 8) >> 3));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 8) & 0xF8, 
-                              (p >> 3) & 0xFC, 
-                              (p << 3) & 0xF8);
-        }
-
-    private:
-        const Gamma* m_gamma;
-    };
-
-
-
-    //=====================================================blender_rgbAAA
-    struct blender_rgbAAA
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 14) & 0xFFC0;
-            calc_type g = (rgb >> 4)  & 0xFFC0;
-            calc_type b = (rgb << 6)  & 0xFFC0;
-            *p = (pixel_type)
-               (((((cr - r) * alpha + (r << 16)) >> 2)  & 0x3FF00000) |
-                ((((cg - g) * alpha + (g << 16)) >> 12) & 0x000FFC00) |
-                 (((cb - b) * alpha + (b << 16)) >> 22) | 0xC0000000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xFFC0) << 14) | 
-                                ((g & 0xFFC0) << 4) | 
-                                 (b >> 6) | 0xC0000000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 14) & 0xFFC0, 
-                              (p >> 4)  & 0xFFC0, 
-                              (p << 6)  & 0xFFC0);
-        }
-    };
-
-
-
-    //==================================================blender_rgbAAA_pre
-    struct blender_rgbAAA_pre
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned cover)
-        {
-            alpha = color_type::base_mask - alpha;
-            cover = (cover + 1) << (color_type::base_shift - 8);
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 14) & 0xFFC0;
-            calc_type g = (rgb >> 4)  & 0xFFC0;
-            calc_type b = (rgb << 6)  & 0xFFC0;
-            *p = (pixel_type)
-               ((((r * alpha + cr * cover) >> 2)  & 0x3FF00000) |
-                (((g * alpha + cg * cover) >> 12) & 0x000FFC00) |
-                 ((b * alpha + cb * cover) >> 22) | 0xC0000000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xFFC0) << 14) | 
-                                ((g & 0xFFC0) << 4) | 
-                                 (b >> 6) | 0xC0000000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 14) & 0xFFC0, 
-                              (p >> 4)  & 0xFFC0, 
-                              (p << 6)  & 0xFFC0);
-        }
-    };
-
-
-
-    //=================================================blender_rgbAAA_gamma
-    template<class Gamma> class blender_rgbAAA_gamma
-    {
-    public:
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-        typedef Gamma gamma_type;
-
-        blender_rgbAAA_gamma() : m_gamma(0) {}
-        void gamma(const gamma_type& g) { m_gamma = &g; }
-
-        AGG_INLINE void blend_pix(pixel_type* p, 
-                                  unsigned cr, unsigned cg, unsigned cb,
-                                  unsigned alpha, 
-                                  unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = m_gamma->dir((rgb >> 14) & 0xFFC0);
-            calc_type g = m_gamma->dir((rgb >> 4)  & 0xFFC0);
-            calc_type b = m_gamma->dir((rgb << 6)  & 0xFFC0);
-            *p = (pixel_type)
-               (((m_gamma->inv(((m_gamma->dir(cr) - r) * alpha + (r << 16)) >> 16) << 14) & 0x3FF00000) |
-                ((m_gamma->inv(((m_gamma->dir(cg) - g) * alpha + (g << 16)) >> 16) << 4 ) & 0x000FFC00) |
-                 (m_gamma->inv(((m_gamma->dir(cb) - b) * alpha + (b << 16)) >> 16) >> 6 ) | 0xC0000000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xFFC0) << 14) | 
-                                ((g & 0xFFC0) << 4) | 
-                                 (b >> 6) | 0xC0000000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 14) & 0xFFC0, 
-                              (p >> 4)  & 0xFFC0, 
-                              (p << 6)  & 0xFFC0);
-        }
-    private:
-        const Gamma* m_gamma;
-    };
-
-
-    //=====================================================blender_bgrAAA
-    struct blender_bgrAAA
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned)
-        {
-            pixel_type bgr = *p;
-            calc_type b = (bgr >> 14) & 0xFFC0;
-            calc_type g = (bgr >> 4)  & 0xFFC0;
-            calc_type r = (bgr << 6)  & 0xFFC0;
-            *p = (pixel_type)
-               (((((cb - b) * alpha + (b << 16)) >> 2)  & 0x3FF00000) |
-                ((((cg - g) * alpha + (g << 16)) >> 12) & 0x000FFC00) |
-                 (((cr - r) * alpha + (r << 16)) >> 22) | 0xC0000000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((b & 0xFFC0) << 14) | 
-                                ((g & 0xFFC0) << 4) | 
-                                 (r >> 6) | 0xC0000000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p << 6)  & 0xFFC0, 
-                              (p >> 4)  & 0xFFC0, 
-                              (p >> 14) & 0xFFC0);
-        }
-    };
-
-
-
-    //=================================================blender_bgrAAA_pre
-    struct blender_bgrAAA_pre
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned cover)
-        {
-            alpha = color_type::base_mask - alpha;
-            cover = (cover + 1) << (color_type::base_shift - 8);
-            pixel_type bgr = *p;
-            calc_type b = (bgr >> 14) & 0xFFC0;
-            calc_type g = (bgr >> 4)  & 0xFFC0;
-            calc_type r = (bgr << 6)  & 0xFFC0;
-            *p = (pixel_type)
-               ((((b * alpha + cb * cover) >> 2)  & 0x3FF00000) |
-                (((g * alpha + cg * cover) >> 12) & 0x000FFC00) |
-                 ((r * alpha + cr * cover) >> 22) | 0xC0000000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((b & 0xFFC0) << 14) | 
-                                ((g & 0xFFC0) << 4) | 
-                                 (r >> 6) | 0xC0000000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p << 6)  & 0xFFC0, 
-                              (p >> 4)  & 0xFFC0, 
-                              (p >> 14) & 0xFFC0);
-        }
-    };
-
-
-
-    //=================================================blender_bgrAAA_gamma
-    template<class Gamma> class blender_bgrAAA_gamma
-    {
-    public:
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-        typedef Gamma gamma_type;
-
-        blender_bgrAAA_gamma() : m_gamma(0) {}
-        void gamma(const gamma_type& g) { m_gamma = &g; }
-
-        AGG_INLINE void blend_pix(pixel_type* p, 
-                                  unsigned cr, unsigned cg, unsigned cb,
-                                  unsigned alpha, 
-                                  unsigned)
-        {
-            pixel_type bgr = *p;
-            calc_type b = m_gamma->dir((bgr >> 14) & 0xFFC0);
-            calc_type g = m_gamma->dir((bgr >> 4)  & 0xFFC0);
-            calc_type r = m_gamma->dir((bgr << 6)  & 0xFFC0);
-            *p = (pixel_type)
-               (((m_gamma->inv(((m_gamma->dir(cb) - b) * alpha + (b << 16)) >> 16) << 14) & 0x3FF00000) |
-                ((m_gamma->inv(((m_gamma->dir(cg) - g) * alpha + (g << 16)) >> 16) << 4 ) & 0x000FFC00) |
-                 (m_gamma->inv(((m_gamma->dir(cr) - r) * alpha + (r << 16)) >> 16) >> 6 ) | 0xC0000000);
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((b & 0xFFC0) << 14) | 
-                                ((g & 0xFFC0) << 4) | 
-                                 (r >> 6) | 0xC0000000);
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p << 6)  & 0xFFC0, 
-                              (p >> 4)  & 0xFFC0, 
-                              (p >> 14) & 0xFFC0);
-        }
-
-    private:
-        const Gamma* m_gamma;
-    };
-
-
-
-    //=====================================================blender_rgbBBA
-    struct blender_rgbBBA
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 16) & 0xFFE0;
-            calc_type g = (rgb >> 5)  & 0xFFE0;
-            calc_type b = (rgb << 6)  & 0xFFC0;
-            *p = (pixel_type)
-               (((((cr - r) * alpha + (r << 16))      ) & 0xFFE00000) |
-                ((((cg - g) * alpha + (g << 16)) >> 11) & 0x001FFC00) |
-                 (((cb - b) * alpha + (b << 16)) >> 22));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xFFE0) << 16) | ((g & 0xFFE0) << 5) | (b >> 6));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 16) & 0xFFE0, 
-                              (p >> 5)  & 0xFFE0, 
-                              (p << 6)  & 0xFFC0);
-        }
-    };
-
-
-    //=================================================blender_rgbBBA_pre
-    struct blender_rgbBBA_pre
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned cover)
-        {
-            alpha = color_type::base_mask - alpha;
-            cover = (cover + 1) << (color_type::base_shift - 8);
-            pixel_type rgb = *p;
-            calc_type r = (rgb >> 16) & 0xFFE0;
-            calc_type g = (rgb >> 5)  & 0xFFE0;
-            calc_type b = (rgb << 6)  & 0xFFC0;
-            *p = (pixel_type)
-               ((((r * alpha + cr * cover)      ) & 0xFFE00000) |
-                (((g * alpha + cg * cover) >> 11) & 0x001FFC00) |
-                 ((b * alpha + cb * cover) >> 22));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xFFE0) << 16) | ((g & 0xFFE0) << 5) | (b >> 6));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 16) & 0xFFE0, 
-                              (p >> 5)  & 0xFFE0, 
-                              (p << 6)  & 0xFFC0);
-        }
-    };
-
-
-
-    //=================================================blender_rgbBBA_gamma
-    template<class Gamma> class blender_rgbBBA_gamma
-    {
-    public:
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-        typedef Gamma gamma_type;
-
-        blender_rgbBBA_gamma() : m_gamma(0) {}
-        void gamma(const gamma_type& g) { m_gamma = &g; }
-
-        AGG_INLINE void blend_pix(pixel_type* p, 
-                                  unsigned cr, unsigned cg, unsigned cb,
-                                  unsigned alpha, 
-                                  unsigned)
-        {
-            pixel_type rgb = *p;
-            calc_type r = m_gamma->dir((rgb >> 16) & 0xFFE0);
-            calc_type g = m_gamma->dir((rgb >> 5)  & 0xFFE0);
-            calc_type b = m_gamma->dir((rgb << 6)  & 0xFFC0);
-            *p = (pixel_type)
-               (((m_gamma->inv(((m_gamma->dir(cr) - r) * alpha + (r << 16)) >> 16) << 16) & 0xFFE00000) |
-                ((m_gamma->inv(((m_gamma->dir(cg) - g) * alpha + (g << 16)) >> 16) << 5 ) & 0x001FFC00) |
-                 (m_gamma->inv(((m_gamma->dir(cb) - b) * alpha + (b << 16)) >> 16) >> 6 ));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((r & 0xFFE0) << 16) | ((g & 0xFFE0) << 5) | (b >> 6));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p >> 16) & 0xFFE0, 
-                              (p >> 5)  & 0xFFE0, 
-                              (p << 6)  & 0xFFC0);
-        }
-
-    private:
-        const Gamma* m_gamma;
-    };
-
-
-    //=====================================================blender_bgrABB
-    struct blender_bgrABB
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned)
-        {
-            pixel_type bgr = *p;
-            calc_type b = (bgr >> 16) & 0xFFC0;
-            calc_type g = (bgr >> 6)  & 0xFFE0;
-            calc_type r = (bgr << 5)  & 0xFFE0;
-            *p = (pixel_type)
-               (((((cb - b) * alpha + (b << 16))      ) & 0xFFC00000) |
-                ((((cg - g) * alpha + (g << 16)) >> 10) & 0x003FF800) |
-                 (((cr - r) * alpha + (r << 16)) >> 21));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((b & 0xFFC0) << 16) | ((g & 0xFFE0) << 6) | (r >> 5));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p << 5)  & 0xFFE0,
-                              (p >> 6)  & 0xFFE0, 
-                              (p >> 16) & 0xFFC0);
-        }
-    };
-
-
-    //=================================================blender_bgrABB_pre
-    struct blender_bgrABB_pre
-    {
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-
-        static AGG_INLINE void blend_pix(pixel_type* p, 
-                                         unsigned cr, unsigned cg, unsigned cb,
-                                         unsigned alpha, 
-                                         unsigned cover)
-        {
-            alpha = color_type::base_mask - alpha;
-            cover = (cover + 1) << (color_type::base_shift - 8);
-            pixel_type bgr = *p;
-            calc_type b = (bgr >> 16) & 0xFFC0;
-            calc_type g = (bgr >> 6)  & 0xFFE0;
-            calc_type r = (bgr << 5)  & 0xFFE0;
-            *p = (pixel_type)
-               ((((b * alpha + cb * cover)      ) & 0xFFC00000) |
-                (((g * alpha + cg * cover) >> 10) & 0x003FF800) |
-                 ((r * alpha + cr * cover) >> 21));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((b & 0xFFC0) << 16) | ((g & 0xFFE0) << 6) | (r >> 5));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p << 5)  & 0xFFE0,
-                              (p >> 6)  & 0xFFE0, 
-                              (p >> 16) & 0xFFC0);
-        }
-    };
-
-
-
-    //=================================================blender_bgrABB_gamma
-    template<class Gamma> class blender_bgrABB_gamma
-    {
-    public:
-        typedef rgba16 color_type;
-        typedef color_type::value_type value_type;
-        typedef color_type::calc_type calc_type;
-        typedef int32u pixel_type;
-        typedef Gamma gamma_type;
-
-        blender_bgrABB_gamma() : m_gamma(0) {}
-        void gamma(const gamma_type& g) { m_gamma = &g; }
-
-        AGG_INLINE void blend_pix(pixel_type* p, 
-                                  unsigned cr, unsigned cg, unsigned cb,
-                                  unsigned alpha, 
-                                  unsigned)
-        {
-            pixel_type bgr = *p;
-            calc_type b = m_gamma->dir((bgr >> 16) & 0xFFC0);
-            calc_type g = m_gamma->dir((bgr >> 6)  & 0xFFE0);
-            calc_type r = m_gamma->dir((bgr << 5)  & 0xFFE0);
-            *p = (pixel_type)
-               (((m_gamma->inv(((m_gamma->dir(cb) - b) * alpha + (b << 16)) >> 16) << 16) & 0xFFC00000) |
-                ((m_gamma->inv(((m_gamma->dir(cg) - g) * alpha + (g << 16)) >> 16) << 6 ) & 0x003FF800) |
-                 (m_gamma->inv(((m_gamma->dir(cr) - r) * alpha + (r << 16)) >> 16) >> 5 ));
-        }
-
-        static AGG_INLINE pixel_type make_pix(unsigned r, unsigned g, unsigned b)
-        {
-            return (pixel_type)(((b & 0xFFC0) << 16) | ((g & 0xFFE0) << 6) | (r >> 5));
-        }
-
-        static AGG_INLINE color_type make_color(pixel_type p)
-        {
-            return color_type((p << 5)  & 0xFFE0,
-                              (p >> 6)  & 0xFFE0, 
-                              (p >> 16) & 0xFFC0);
-        }
-
-    private:
-        const Gamma* m_gamma;
-    };
-
-
-    
-    //===========================================pixfmt_alpha_blend_rgb_packed
-    template<class Blender,  class RenBuf> class pixfmt_alpha_blend_rgb_packed
-    {
-    public:
-        typedef RenBuf   rbuf_type;
-        typedef typename rbuf_type::row_data row_data;
-        typedef Blender  blender_type;
-        typedef typename blender_type::color_type color_type;
-        typedef typename blender_type::pixel_type pixel_type;
-        typedef int                               order_type; // A fake one
-        typedef typename color_type::value_type   value_type;
-        typedef typename color_type::calc_type    calc_type;
-        enum base_scale_e 
-        {
-            base_shift = color_type::base_shift,
-            base_scale = color_type::base_scale,
-            base_mask  = color_type::base_mask,
-            pix_width  = sizeof(pixel_type),
-        };
-
-    private:
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c, unsigned cover)
-        {
-            if (c.a)
-            {
-                calc_type alpha = (calc_type(c.a) * (cover + 1)) >> 8;
-                if(alpha == base_mask)
-                {
-                    *p = m_blender.make_pix(c.r, c.g, c.b);
-                }
-                else
-                {
-                    m_blender.blend_pix(p, c.r, c.g, c.b, alpha, cover);
-                }
-            }
-        }
-
-    public:
-        //--------------------------------------------------------------------
-        explicit pixfmt_alpha_blend_rgb_packed(rbuf_type& rb) : m_rbuf(&rb) {}
-        void attach(rbuf_type& rb) { m_rbuf = &rb; }
-
-        //--------------------------------------------------------------------
-        template<class PixFmt>
-        bool attach(PixFmt& pixf, int x1, int y1, int x2, int y2)
-        {
-            rect_i r(x1, y1, x2, y2);
-            if(r.clip(rect_i(0, 0, pixf.width()-1, pixf.height()-1)))
-            {
-                int stride = pixf.stride();
-                m_rbuf->attach(pixf.pix_ptr(r.x1, stride < 0 ? r.y2 : r.y1), 
-                               (r.x2 - r.x1) + 1,
-                               (r.y2 - r.y1) + 1,
-                               stride);
-                return true;
-            }
-            return false;
-        }
-
-        Blender& blender() { return m_blender; }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE unsigned width()  const { return m_rbuf->width();  }
-        AGG_INLINE unsigned height() const { return m_rbuf->height(); }
-        AGG_INLINE int      stride() const { return m_rbuf->stride(); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE       int8u* row_ptr(int y)       { return m_rbuf->row_ptr(y); }
-        AGG_INLINE const int8u* row_ptr(int y) const { return m_rbuf->row_ptr(y); }
-        AGG_INLINE row_data     row(int y)     const { return m_rbuf->row(y); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE int8u* pix_ptr(int x, int y)
-        {
-            return m_rbuf->row_ptr(y) + x * pix_width;
-        }
-
-        AGG_INLINE const int8u* pix_ptr(int x, int y) const
-        {
-            return m_rbuf->row_ptr(y) + x * pix_width;
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void make_pix(int8u* p, const color_type& c)
-        {
-            *(pixel_type*)p = m_blender.make_pix(c.r, c.g, c.b);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE color_type pixel(int x, int y) const
-        {
-            return m_blender.make_color(((pixel_type*)m_rbuf->row_ptr(y))[x]);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_pixel(int x, int y, const color_type& c)
-        {
-            ((pixel_type*)
-                m_rbuf->row_ptr(x, y, 1))[x] = 
-                    m_blender.make_pix(c.r, c.g, c.b);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pixel(int x, int y, const color_type& c, int8u cover)
-        {
-            copy_or_blend_pix((pixel_type*)m_rbuf->row_ptr(x, y, 1) + x, c, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_hline(int x, int y, 
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y, len) + x;
-            pixel_type v = m_blender.make_pix(c.r, c.g, c.b);
-            do
-            {
-                *p++ = v;
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_vline(int x, int y,
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            pixel_type v = m_blender.make_pix(c.r, c.g, c.b);
-            do
-            {
-                pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y++, 1) + x;
-                *p = v;
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_hline(int x, int y,
-                         unsigned len, 
-                         const color_type& c,
-                         int8u cover)
-        {
-            if (c.a)
-            {
-                pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y, len) + x;
-                calc_type alpha = (calc_type(c.a) * (cover + 1)) >> 8;
-                if(alpha == base_mask)
-                {
-                    pixel_type v = m_blender.make_pix(c.r, c.g, c.b);
-                    do
-                    {
-                        *p++ = v;
-                    }
-                    while(--len);
-                }
-                else
-                {
-                    do
-                    {
-                        m_blender.blend_pix(p, c.r, c.g, c.b, alpha, cover);
-                        ++p;
-                    }
-                    while(--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void blend_vline(int x, int y,
-                         unsigned len, 
-                         const color_type& c,
-                         int8u cover)
-        {
-            if (c.a)
-            {
-                calc_type alpha = (calc_type(c.a) * (cover + 1)) >> 8;
-                if(alpha == base_mask)
-                {
-                    pixel_type v = m_blender.make_pix(c.r, c.g, c.b);
-                    do
-                    {
-                        ((pixel_type*)m_rbuf->row_ptr(x, y++, 1))[x] = v;
-                    }
-                    while(--len);
-                }
-                else
-                {
-                    do
-                    {
-                        m_blender.blend_pix(
-                            (pixel_type*)m_rbuf->row_ptr(x, y++, 1), 
-                            c.r, c.g, c.b, alpha, cover);
-                    }
-                    while(--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void blend_solid_hspan(int x, int y,
-                               unsigned len, 
-                               const color_type& c,
-                               const int8u* covers)
-        {
-            pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y, len) + x;
-            do 
-            {
-                copy_or_blend_pix(p, c, *covers++);
-                ++p;
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_solid_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type& c,
-                               const int8u* covers)
-        {
-            do 
-            {
-                copy_or_blend_pix((pixel_type*)m_rbuf->row_ptr(x, y++, 1) + x, 
-                                  c, *covers++);
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_color_hspan(int x, int y,
-                              unsigned len, 
-                              const color_type* colors)
-        {
-            pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y, len) + x;
-            do 
-            {
-                *p++ = m_blender.make_pix(colors->r, colors->g, colors->b);
-                ++colors;
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_color_vspan(int x, int y,
-                              unsigned len, 
-                              const color_type* colors)
-        {
-            do 
-            {
-                pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y++, 1) + x;
-                *p = m_blender.make_pix(colors->r, colors->g, colors->b);
-                ++colors;
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_hspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const int8u* covers,
-                               int8u cover)
-        {
-            pixel_type* p = (pixel_type*)m_rbuf->row_ptr(x, y, len) + x;
-            do 
-            {
-                copy_or_blend_pix(p++, *colors++, covers ? *covers++ : cover);
-            }
-            while(--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const int8u* covers,
-                               int8u cover)
-        {
-            do 
-            {
-                copy_or_blend_pix((pixel_type*)m_rbuf->row_ptr(x, y++, 1) + x, 
-                                  *colors++, covers ? *covers++ : cover);
-            }
-            while(--len);
-        }
-        
-        //--------------------------------------------------------------------
-        template<class RenBuf2>
-        void copy_from(const RenBuf2& from, 
-                       int xdst, int ydst,
-                       int xsrc, int ysrc,
-                       unsigned len)
-        {
-            const int8u* p = from.row_ptr(ysrc);
-            if(p)
-            {
-                memmove(m_rbuf->row_ptr(xdst, ydst, len) + xdst * pix_width, 
-                        p + xsrc * pix_width, 
-                        len * pix_width);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        template<class SrcPixelFormatRenderer>
-        void blend_from(const SrcPixelFormatRenderer& from, 
-                        int xdst, int ydst,
-                        int xsrc, int ysrc,
-                        unsigned len,
-                        int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::order_type src_order;
-
-            const value_type* psrc = (const value_type*)from.row_ptr(ysrc);
-            if(psrc)
-            {
-                psrc += xsrc * 4;
-                pixel_type* pdst = 
-                    (pixel_type*)m_rbuf->row_ptr(xdst, ydst, len) + xdst;
-                do 
-                {
-                    value_type alpha = psrc[src_order::A];
-                    if(alpha)
-                    {
-                        if(alpha == base_mask && cover == 255)
-                        {
-                            *pdst = m_blender.make_pix(psrc[src_order::R], 
-                                                       psrc[src_order::G],
-                                                       psrc[src_order::B]);
-                        }
-                        else
-                        {
-                            m_blender.blend_pix(pdst, 
-                                                psrc[src_order::R],
-                                                psrc[src_order::G],
-                                                psrc[src_order::B],
-                                                alpha,
-                                                cover);
-                        }
-                    }
-                    psrc += 4;
-                    ++pdst;
-                }
-                while(--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        template<class SrcPixelFormatRenderer>
-        void blend_from_color(const SrcPixelFormatRenderer& from, 
-                              const color_type& color,
-                              int xdst, int ydst,
-                              int xsrc, int ysrc,
-                              unsigned len,
-                              int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::value_type src_value_type;
-            const src_value_type* psrc = (src_value_type*)from.row_ptr(ysrc);
-            if(psrc)
-            {
-                psrc += xsrc * SrcPixelFormatRenderer::pix_step + SrcPixelFormatRenderer::pix_offset;
-                pixel_type* pdst = 
-                    (pixel_type*)m_rbuf->row_ptr(xdst, ydst, len) + xdst;
-
-                do 
-                {
-                    m_blender.blend_pix(pdst, 
-                                        color.r, color.g, color.b, color.a,
-                                        cover);
-                    psrc += SrcPixelFormatRenderer::pix_step;
-                    ++pdst;
-                }
-                while(--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        template<class SrcPixelFormatRenderer>
-        void blend_from_lut(const SrcPixelFormatRenderer& from, 
-                            const color_type* color_lut,
-                            int xdst, int ydst,
-                            int xsrc, int ysrc,
-                            unsigned len,
-                            int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::value_type src_value_type;
-            const src_value_type* psrc = (src_value_type*)from.row_ptr(ysrc);
-            if(psrc)
-            {
-                psrc += xsrc * SrcPixelFormatRenderer::pix_step + SrcPixelFormatRenderer::pix_offset;
-                pixel_type* pdst = 
-                    (pixel_type*)m_rbuf->row_ptr(xdst, ydst, len) + xdst;
-
-                do 
-                {
-                    const color_type& color = color_lut[*psrc];
-                    m_blender.blend_pix(pdst, 
-                                        color.r, color.g, color.b, color.a,
-                                        cover);
-                    psrc += SrcPixelFormatRenderer::pix_step;
-                    ++pdst;
-                }
-                while(--len);
-            }
-        }
-
-
-
-    private:
-        rbuf_type* m_rbuf;
-        Blender    m_blender;
-    };
-
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgb555, rendering_buffer> pixfmt_rgb555; //----pixfmt_rgb555
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgb565, rendering_buffer> pixfmt_rgb565; //----pixfmt_rgb565
-
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgb555_pre, rendering_buffer> pixfmt_rgb555_pre; //----pixfmt_rgb555_pre
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgb565_pre, rendering_buffer> pixfmt_rgb565_pre; //----pixfmt_rgb565_pre
-
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgbAAA, rendering_buffer> pixfmt_rgbAAA; //----pixfmt_rgbAAA
-    typedef pixfmt_alpha_blend_rgb_packed<blender_bgrAAA, rendering_buffer> pixfmt_bgrAAA; //----pixfmt_bgrAAA
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgbBBA, rendering_buffer> pixfmt_rgbBBA; //----pixfmt_rgbBBA
-    typedef pixfmt_alpha_blend_rgb_packed<blender_bgrABB, rendering_buffer> pixfmt_bgrABB; //----pixfmt_bgrABB
-
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgbAAA_pre, rendering_buffer> pixfmt_rgbAAA_pre; //----pixfmt_rgbAAA_pre
-    typedef pixfmt_alpha_blend_rgb_packed<blender_bgrAAA_pre, rendering_buffer> pixfmt_bgrAAA_pre; //----pixfmt_bgrAAA_pre
-    typedef pixfmt_alpha_blend_rgb_packed<blender_rgbBBA_pre, rendering_buffer> pixfmt_rgbBBA_pre; //----pixfmt_rgbBBA_pre
-    typedef pixfmt_alpha_blend_rgb_packed<blender_bgrABB_pre, rendering_buffer> pixfmt_bgrABB_pre; //----pixfmt_bgrABB_pre
-
-
-    //-----------------------------------------------------pixfmt_rgb555_gamma
-    template<class Gamma> class pixfmt_rgb555_gamma : 
-    public pixfmt_alpha_blend_rgb_packed<blender_rgb555_gamma<Gamma>, 
-                                         rendering_buffer>
-    {
-    public:
-        pixfmt_rgb555_gamma(rendering_buffer& rb, const Gamma& g) :
-            pixfmt_alpha_blend_rgb_packed<blender_rgb555_gamma<Gamma>, 
-                                          rendering_buffer>(rb) 
-        {
-            this->blender().gamma(g);
-        }
-    };
-
-
-    //-----------------------------------------------------pixfmt_rgb565_gamma
-    template<class Gamma> class pixfmt_rgb565_gamma : 
-    public pixfmt_alpha_blend_rgb_packed<blender_rgb565_gamma<Gamma>, rendering_buffer>
-    {
-    public:
-        pixfmt_rgb565_gamma(rendering_buffer& rb, const Gamma& g) :
-            pixfmt_alpha_blend_rgb_packed<blender_rgb565_gamma<Gamma>, rendering_buffer>(rb) 
-        {
-            this->blender().gamma(g);
-        }
-    };
-
-
-    //-----------------------------------------------------pixfmt_rgbAAA_gamma
-    template<class Gamma> class pixfmt_rgbAAA_gamma : 
-    public pixfmt_alpha_blend_rgb_packed<blender_rgbAAA_gamma<Gamma>, 
-                                         rendering_buffer>
-    {
-    public:
-        pixfmt_rgbAAA_gamma(rendering_buffer& rb, const Gamma& g) :
-            pixfmt_alpha_blend_rgb_packed<blender_rgbAAA_gamma<Gamma>, 
-                                          rendering_buffer>(rb) 
-        {
-            this->blender().gamma(g);
-        }
-    };
-
-
-    //-----------------------------------------------------pixfmt_bgrAAA_gamma
-    template<class Gamma> class pixfmt_bgrAAA_gamma : 
-    public pixfmt_alpha_blend_rgb_packed<blender_bgrAAA_gamma<Gamma>, 
-                                         rendering_buffer>
-    {
-    public:
-        pixfmt_bgrAAA_gamma(rendering_buffer& rb, const Gamma& g) :
-            pixfmt_alpha_blend_rgb_packed<blender_bgrAAA_gamma<Gamma>, 
-                                          rendering_buffer>(rb) 
-        {
-            this->blender().gamma(g);
-        }
-    };
-
-
-    //-----------------------------------------------------pixfmt_rgbBBA_gamma
-    template<class Gamma> class pixfmt_rgbBBA_gamma : 
-    public pixfmt_alpha_blend_rgb_packed<blender_rgbBBA_gamma<Gamma>, 
-                                         rendering_buffer>
-    {
-    public:
-        pixfmt_rgbBBA_gamma(rendering_buffer& rb, const Gamma& g) :
-            pixfmt_alpha_blend_rgb_packed<blender_rgbBBA_gamma<Gamma>, 
-                                          rendering_buffer>(rb) 
-        {
-            this->blender().gamma(g);
-        }
-    };
-
-
-    //-----------------------------------------------------pixfmt_bgrABB_gamma
-    template<class Gamma> class pixfmt_bgrABB_gamma : 
-    public pixfmt_alpha_blend_rgb_packed<blender_bgrABB_gamma<Gamma>, 
-                                         rendering_buffer>
-    {
-    public:
-        pixfmt_bgrABB_gamma(rendering_buffer& rb, const Gamma& g) :
-            pixfmt_alpha_blend_rgb_packed<blender_bgrABB_gamma<Gamma>, 
-                                          rendering_buffer>(rb) 
-        {
-            this->blender().gamma(g);
-        }
-    };
-
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_pixfmt_rgba.h b/xs/src/agg/agg_pixfmt_rgba.h
deleted file mode 100644
index 9c4ab449a..000000000
--- a/xs/src/agg/agg_pixfmt_rgba.h
+++ /dev/null
@@ -1,2803 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_PIXFMT_RGBA_INCLUDED
-#define AGG_PIXFMT_RGBA_INCLUDED
-
-#include <string.h>
-#include <math.h>
-#include "agg_pixfmt_base.h"
-#include "agg_rendering_buffer.h"
-
-namespace agg
-{
-    template<class T> inline T sd_min(T a, T b) { return (a < b) ? a : b; }
-    template<class T> inline T sd_max(T a, T b) { return (a > b) ? a : b; }
-
-    inline rgba & clip(rgba & c)
-    {
-        if (c.a > 1) c.a = 1; else if (c.a < 0) c.a = 0;
-        if (c.r > c.a) c.r = c.a; else if (c.r < 0) c.r = 0;
-        if (c.g > c.a) c.g = c.a; else if (c.g < 0) c.g = 0;
-        if (c.b > c.a) c.b = c.a; else if (c.b < 0) c.b = 0;
-        return c;
-    }
-
-    //=========================================================multiplier_rgba
-    template<class ColorT, class Order> 
-    struct multiplier_rgba
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void premultiply(value_type* p)
-        {
-            value_type a = p[Order::A];
-            p[Order::R] = color_type::multiply(p[Order::R], a);
-            p[Order::G] = color_type::multiply(p[Order::G], a);
-            p[Order::B] = color_type::multiply(p[Order::B], a);
-        }
-
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void demultiply(value_type* p)
-        {
-            value_type a = p[Order::A];
-            p[Order::R] = color_type::demultiply(p[Order::R], a);
-            p[Order::G] = color_type::demultiply(p[Order::G], a);
-            p[Order::B] = color_type::demultiply(p[Order::B], a);
-        }
-    };
-
-    //=====================================================apply_gamma_dir_rgba
-    template<class ColorT, class Order, class GammaLut> 
-    class apply_gamma_dir_rgba
-    {
-    public:
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-
-        apply_gamma_dir_rgba(const GammaLut& gamma) : m_gamma(gamma) {}
-
-        AGG_INLINE void operator () (value_type* p)
-        {
-            p[Order::R] = m_gamma.dir(p[Order::R]);
-            p[Order::G] = m_gamma.dir(p[Order::G]);
-            p[Order::B] = m_gamma.dir(p[Order::B]);
-        }
-
-    private:
-        const GammaLut& m_gamma;
-    };
-
-    //=====================================================apply_gamma_inv_rgba
-    template<class ColorT, class Order, class GammaLut> class apply_gamma_inv_rgba
-    {
-    public:
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-
-        apply_gamma_inv_rgba(const GammaLut& gamma) : m_gamma(gamma) {}
-
-        AGG_INLINE void operator () (value_type* p)
-        {
-            p[Order::R] = m_gamma.inv(p[Order::R]);
-            p[Order::G] = m_gamma.inv(p[Order::G]);
-            p[Order::B] = m_gamma.inv(p[Order::B]);
-        }
-
-    private:
-        const GammaLut& m_gamma;
-    };
-
-
-    template<class ColorT, class Order> 
-    struct conv_rgba_pre
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void set_plain_color(value_type* p, color_type c)
-        {
-            c.premultiply();
-            p[Order::R] = c.r;
-            p[Order::G] = c.g;
-            p[Order::B] = c.b;
-            p[Order::A] = c.a;
-        }
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE color_type get_plain_color(const value_type* p)
-        {
-            return color_type(
-                p[Order::R],
-                p[Order::G],
-                p[Order::B],
-                p[Order::A]).demultiply();
-        }
-    };
-
-    template<class ColorT, class Order> 
-    struct conv_rgba_plain
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void set_plain_color(value_type* p, color_type c)
-        {
-            p[Order::R] = c.r;
-            p[Order::G] = c.g;
-            p[Order::B] = c.b;
-            p[Order::A] = c.a;
-        }
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE color_type get_plain_color(const value_type* p)
-        {
-            return color_type(
-                p[Order::R],
-                p[Order::G],
-                p[Order::B],
-                p[Order::A]);
-        }
-    };
-
-    //=============================================================blender_rgba
-    // Blends "plain" (i.e. non-premultiplied) colors into a premultiplied buffer.
-    template<class ColorT, class Order> 
-    struct blender_rgba : conv_rgba_pre<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        // Blend pixels using the non-premultiplied form of Alvy-Ray Smith's
-        // compositing function. Since the render buffer is in fact premultiplied
-        // we omit the initial premultiplication and final demultiplication.
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type cr, value_type cg, value_type cb, value_type alpha, cover_type cover)
-        {
-            blend_pix(p, cr, cg, cb, color_type::mult_cover(alpha, cover));
-        }
-        
-        //--------------------------------------------------------------------
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type cr, value_type cg, value_type cb, value_type alpha)
-        {
-            p[Order::R] = color_type::lerp(p[Order::R], cr, alpha);
-            p[Order::G] = color_type::lerp(p[Order::G], cg, alpha);
-            p[Order::B] = color_type::lerp(p[Order::B], cb, alpha);
-            p[Order::A] = color_type::prelerp(p[Order::A], alpha, alpha);
-        }
-    };
-
-
-    //========================================================blender_rgba_pre
-    // Blends premultiplied colors into a premultiplied buffer.
-    template<class ColorT, class Order> 
-    struct blender_rgba_pre : conv_rgba_pre<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        // Blend pixels using the premultiplied form of Alvy-Ray Smith's
-        // compositing function. 
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type cr, value_type cg, value_type cb, value_type alpha, cover_type cover)
-        {
-            blend_pix(p, 
-                color_type::mult_cover(cr, cover), 
-                color_type::mult_cover(cg, cover), 
-                color_type::mult_cover(cb, cover), 
-                color_type::mult_cover(alpha, cover));
-        }
-        
-        //--------------------------------------------------------------------
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type cr, value_type cg, value_type cb, value_type alpha)
-        {
-            p[Order::R] = color_type::prelerp(p[Order::R], cr, alpha);
-            p[Order::G] = color_type::prelerp(p[Order::G], cg, alpha);
-            p[Order::B] = color_type::prelerp(p[Order::B], cb, alpha);
-            p[Order::A] = color_type::prelerp(p[Order::A], alpha, alpha);
-        }
-    };
-
-    //======================================================blender_rgba_plain
-    // Blends "plain" (non-premultiplied) colors into a plain (non-premultiplied) buffer.
-    template<class ColorT, class Order> 
-    struct blender_rgba_plain : conv_rgba_plain<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        // Blend pixels using the non-premultiplied form of Alvy-Ray Smith's
-        // compositing function. 
-
-        //--------------------------------------------------------------------
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type cr, value_type cg, value_type cb, value_type alpha, cover_type cover)
-        {
-            blend_pix(p, cr, cg, cb, color_type::mult_cover(alpha, cover));
-        }
-        
-        //--------------------------------------------------------------------
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type cr, value_type cg, value_type cb, value_type alpha)
-        {
-            if (alpha > color_type::empty_value())
-            {
-                calc_type a = p[Order::A];
-                calc_type r = color_type::multiply(p[Order::R], a);
-                calc_type g = color_type::multiply(p[Order::G], a);
-                calc_type b = color_type::multiply(p[Order::B], a);
-                p[Order::R] = color_type::lerp(r, cr, alpha);
-                p[Order::G] = color_type::lerp(g, cg, alpha);
-                p[Order::B] = color_type::lerp(b, cb, alpha);
-                p[Order::A] = color_type::prelerp(a, alpha, alpha);
-                multiplier_rgba<ColorT, Order>::demultiply(p);
-            }
-        }
-    };
-
-    // SVG compositing operations.
-    // For specifications, see http://www.w3.org/TR/SVGCompositing/
-
-    //=========================================================comp_op_rgba_clear
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_clear : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = 0
-        // Da'  = 0
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type, value_type, value_type, value_type, cover_type cover)
-        {
-            if (cover >= cover_full)
-            {
-                p[0] = p[1] = p[2] = p[3] = color_type::empty_value(); 
-            }
-            else if (cover > cover_none)
-            {
-                set(p, get(p, cover_full - cover));
-            }
-        }
-    };
-
-    //===========================================================comp_op_rgba_src
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_src : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca
-        // Da'  = Sa
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            if (cover >= cover_full)
-            {
-                set(p, r, g, b, a);
-            }
-            else
-            {
-                rgba s = get(r, g, b, a, cover);
-                rgba d = get(p, cover_full - cover);
-                d.r += s.r;
-                d.g += s.g;
-                d.b += s.b;
-                d.a += s.a;
-                set(p, d);
-            }
-        }
-    };
-
-    //===========================================================comp_op_rgba_dst
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_dst : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-
-        // Dca' = Dca.Sa + Dca.(1 - Sa) = Dca
-        // Da'  = Da.Sa + Da.(1 - Sa) = Da
-        static AGG_INLINE void blend_pix(value_type*, 
-            value_type, value_type, value_type, value_type, cover_type)
-        {
-            // Well, that was easy!
-        }
-    };
-
-    //======================================================comp_op_rgba_src_over
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_src_over : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca + Dca.(1 - Sa) = Dca + Sca - Dca.Sa
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-#if 1
-            blender_rgba_pre<ColorT, Order>::blend_pix(p, r, g, b, a, cover);
-#else
-            rgba s = get(r, g, b, a, cover);
-            rgba d = get(p);
-            d.r += s.r - d.r * s.a;
-            d.g += s.g - d.g * s.a;
-            d.b += s.b - d.b * s.a;
-            d.a += s.a - d.a * s.a;
-            set(p, d);
-#endif
-        }
-    };
-
-    //======================================================comp_op_rgba_dst_over
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_dst_over : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Dca + Sca.(1 - Da)
-        // Da'  = Sa + Da - Sa.Da = Da + Sa.(1 - Da)
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            rgba d = get(p);
-            double d1a = 1 - d.a;
-            d.r += s.r * d1a;
-            d.g += s.g * d1a;
-            d.b += s.b * d1a;
-            d.a += s.a * d1a;
-            set(p, d);
-        }
-    };
-
-    //======================================================comp_op_rgba_src_in
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_src_in : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca.Da
-        // Da'  = Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            double da = ColorT::to_double(p[Order::A]);
-            if (da > 0)
-            {
-                rgba s = get(r, g, b, a, cover);
-                rgba d = get(p, cover_full - cover);
-                d.r += s.r * da;
-                d.g += s.g * da;
-                d.b += s.b * da;
-                d.a += s.a * da;
-                set(p, d);
-            }
-        }
-    };
-
-    //======================================================comp_op_rgba_dst_in
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_dst_in : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Dca.Sa
-        // Da'  = Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type, value_type, value_type, value_type a, cover_type cover)
-        {
-            double sa = ColorT::to_double(a);
-            rgba d = get(p, cover_full - cover);
-            rgba d2 = get(p, cover);
-            d.r += d2.r * sa;
-            d.g += d2.g * sa;
-            d.b += d2.b * sa;
-            d.a += d2.a * sa;
-            set(p, d);
-        }
-    };
-
-    //======================================================comp_op_rgba_src_out
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_src_out : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca.(1 - Da)
-        // Da'  = Sa.(1 - Da) 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            rgba d = get(p, cover_full - cover);
-            double d1a = 1 - ColorT::to_double(p[Order::A]);
-            d.r += s.r * d1a;
-            d.g += s.g * d1a;
-            d.b += s.b * d1a;
-            d.a += s.a * d1a;
-            set(p, d);
-        }
-    };
-
-    //======================================================comp_op_rgba_dst_out
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_dst_out : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Dca.(1 - Sa) 
-        // Da'  = Da.(1 - Sa) 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type, value_type, value_type, value_type a, cover_type cover)
-        {
-            rgba d = get(p, cover_full - cover);
-            rgba dc = get(p, cover);
-            double s1a = 1 - ColorT::to_double(a);
-            d.r += dc.r * s1a;
-            d.g += dc.g * s1a;
-            d.b += dc.b * s1a;
-            d.a += dc.a * s1a;
-            set(p, d);
-        }
-    };
-
-    //=====================================================comp_op_rgba_src_atop
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_src_atop : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca.Da + Dca.(1 - Sa)
-        // Da'  = Da
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            rgba d = get(p);
-            double s1a = 1 - s.a;
-            d.r = s.r * d.a + d.r * s1a;
-            d.g = s.g * d.a + d.g * s1a;
-            d.b = s.b * d.a + d.g * s1a;
-            set(p, d);
-        }
-    };
-
-    //=====================================================comp_op_rgba_dst_atop
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_dst_atop : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Dca.Sa + Sca.(1 - Da)
-        // Da'  = Sa 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba sc = get(r, g, b, a, cover);
-            rgba dc = get(p, cover);
-            rgba d = get(p, cover_full - cover);
-            double sa = ColorT::to_double(a);
-            double d1a = 1 - ColorT::to_double(p[Order::A]);
-            d.r += dc.r * sa + sc.r * d1a;
-            d.g += dc.g * sa + sc.g * d1a;
-            d.b += dc.b * sa + sc.b * d1a;
-            d.a += sc.a;
-            set(p, d);
-        }
-    };
-
-    //=========================================================comp_op_rgba_xor
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_xor : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca.(1 - Da) + Dca.(1 - Sa)
-        // Da'  = Sa + Da - 2.Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            rgba d = get(p);
-            double s1a = 1 - s.a;
-            double d1a = 1 - ColorT::to_double(p[Order::A]);
-            d.r = s.r * d1a + d.r * s1a;
-            d.g = s.g * d1a + d.g * s1a;
-            d.b = s.b * d1a + d.b * s1a;
-            d.a = s.a + d.a - 2 * s.a * d.a;
-            set(p, d);
-        }
-    };
-
-    //=========================================================comp_op_rgba_plus
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_plus : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca + Dca
-        // Da'  = Sa + Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                d.a = sd_min(d.a + s.a, 1.0);
-                d.r = sd_min(d.r + s.r, d.a);
-                d.g = sd_min(d.g + s.g, d.a);
-                d.b = sd_min(d.b + s.b, d.a);
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //========================================================comp_op_rgba_minus
-    // Note: not included in SVG spec.
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_minus : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Dca - Sca
-        // Da' = 1 - (1 - Sa).(1 - Da) = Da + Sa - Sa.Da
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                d.a += s.a - s.a * d.a;
-                d.r = sd_max(d.r - s.r, 0.0);
-                d.g = sd_max(d.g - s.g, 0.0);
-                d.b = sd_max(d.b - s.b, 0.0);
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_multiply
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_multiply : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca.Dca + Sca.(1 - Da) + Dca.(1 - Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                double s1a = 1 - s.a;
-                double d1a = 1 - d.a;
-                d.r = s.r * d.r + s.r * d1a + d.r * s1a;
-                d.g = s.g * d.g + s.g * d1a + d.g * s1a;
-                d.b = s.b * d.b + s.b * d1a + d.b * s1a;
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_screen
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_screen : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca + Dca - Sca.Dca
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                d.r += s.r - s.r * d.r;
-                d.g += s.g - s.g * d.g;
-                d.b += s.b - s.b * d.b;
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_overlay
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_overlay : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // if 2.Dca <= Da
-        //   Dca' = 2.Sca.Dca + Sca.(1 - Da) + Dca.(1 - Sa)
-        // otherwise
-        //   Dca' = Sa.Da - 2.(Da - Dca).(Sa - Sca) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // 
-        // Da' = Sa + Da - Sa.Da
-        static AGG_INLINE double calc(double dca, double sca, double da, double sa, double sada, double d1a, double s1a)
-        {
-            return (2 * dca <= da) ? 
-                2 * sca * dca + sca * d1a + dca * s1a : 
-                sada - 2 * (da - dca) * (sa - sca) + sca * d1a + dca * s1a;
-        }
-
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                double d1a = 1 - d.a;
-                double s1a = 1 - s.a;
-                double sada = s.a * d.a;
-                d.r = calc(d.r, s.r, d.a, s.a, sada, d1a, s1a);
-                d.g = calc(d.g, s.g, d.a, s.a, sada, d1a, s1a);
-                d.b = calc(d.b, s.b, d.a, s.a, sada, d1a, s1a);
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_darken
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_darken : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = min(Sca.Da, Dca.Sa) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                double d1a = 1 - d.a;
-                double s1a = 1 - s.a;
-                d.r = sd_min(s.r * d.a, d.r * s.a) + s.r * d1a + d.r * s1a;
-                d.g = sd_min(s.g * d.a, d.g * s.a) + s.g * d1a + d.g * s1a;
-                d.b = sd_min(s.b * d.a, d.b * s.a) + s.b * d1a + d.b * s1a;
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_lighten
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_lighten : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = max(Sca.Da, Dca.Sa) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                double d1a = 1 - d.a;
-                double s1a = 1 - s.a;
-                d.r = sd_max(s.r * d.a, d.r * s.a) + s.r * d1a + d.r * s1a;
-                d.g = sd_max(s.g * d.a, d.g * s.a) + s.g * d1a + d.g * s1a;
-                d.b = sd_max(s.b * d.a, d.b * s.a) + s.b * d1a + d.b * s1a;
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_color_dodge
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_color_dodge : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // if Sca == Sa and Dca == 0
-        //     Dca' = Sca.(1 - Da) + Dca.(1 - Sa) = Sca.(1 - Da)
-        // otherwise if Sca == Sa
-        //     Dca' = Sa.Da + Sca.(1 - Da) + Dca.(1 - Sa)
-        // otherwise if Sca < Sa
-        //     Dca' = Sa.Da.min(1, Dca/Da.Sa/(Sa - Sca)) + Sca.(1 - Da) + Dca.(1 - Sa)
-        //
-        // Da'  = Sa + Da - Sa.Da
-        static AGG_INLINE double calc(double dca, double sca, double da, double sa, double sada, double d1a, double s1a)
-        {
-            if (sca < sa) return sada * sd_min(1.0, (dca / da) * sa / (sa - sca)) + sca * d1a + dca * s1a;
-            if (dca > 0) return sada + sca * d1a + dca * s1a;
-            return sca * d1a;
-        }
-
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                if (d.a > 0)
-                {
-                    double sada = s.a * d.a;
-                    double s1a = 1 - s.a;
-                    double d1a = 1 - d.a;
-                    d.r = calc(d.r, s.r, d.a, s.a, sada, d1a, s1a);
-                    d.g = calc(d.g, s.g, d.a, s.a, sada, d1a, s1a);
-                    d.b = calc(d.b, s.b, d.a, s.a, sada, d1a, s1a);
-                    d.a += s.a - s.a * d.a;
-                    set(p, clip(d));
-                }
-                else set(p, s);
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_color_burn
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_color_burn : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // if Sca == 0 and Dca == Da
-        //   Dca' = Sa.Da + Dca.(1 - Sa)
-        // otherwise if Sca == 0
-        //   Dca' = Dca.(1 - Sa)
-        // otherwise if Sca > 0
-        //   Dca' =  Sa.Da.(1 - min(1, (1 - Dca/Da).Sa/Sca)) + Sca.(1 - Da) + Dca.(1 - Sa)
-        static AGG_INLINE double calc(double dca, double sca, double da, double sa, double sada, double d1a, double s1a)
-        {
-            if (sca > 0) return sada * (1 - sd_min(1.0, (1 - dca / da) * sa / sca)) + sca * d1a + dca * s1a;
-            if (dca > da) return sada + dca * s1a;
-            return dca * s1a;
-        }
-
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                if (d.a > 0)
-                {
-                    double sada = s.a * d.a;
-                    double s1a = 1 - s.a;
-                    double d1a = 1 - d.a;
-                    d.r = calc(d.r, s.r, d.a, s.a, sada, d1a, s1a);
-                    d.g = calc(d.g, s.g, d.a, s.a, sada, d1a, s1a);
-                    d.b = calc(d.b, s.b, d.a, s.a, sada, d1a, s1a);
-                    d.a += s.a - sada;
-                    set(p, clip(d));
-                }
-                else set(p, s);
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_hard_light
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_hard_light : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // if 2.Sca < Sa
-        //    Dca' = 2.Sca.Dca + Sca.(1 - Da) + Dca.(1 - Sa)
-        // otherwise
-        //    Dca' = Sa.Da - 2.(Da - Dca).(Sa - Sca) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // 
-        // Da'  = Sa + Da - Sa.Da
-        static AGG_INLINE double calc(double dca, double sca, double da, double sa, double sada, double d1a, double s1a)
-        {
-            return (2 * sca < sa) ? 
-                2 * sca * dca + sca * d1a + dca * s1a : 
-                sada - 2 * (da - dca) * (sa - sca) + sca * d1a + dca * s1a;
-        }
-
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                double d1a = 1 - d.a;
-                double s1a = 1 - s.a;
-                double sada = s.a * d.a;
-                d.r = calc(d.r, s.r, d.a, s.a, sada, d1a, s1a);
-                d.g = calc(d.g, s.g, d.a, s.a, sada, d1a, s1a);
-                d.b = calc(d.b, s.b, d.a, s.a, sada, d1a, s1a);
-                d.a += s.a - sada;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_soft_light
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_soft_light : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // if 2.Sca <= Sa
-        //   Dca' = Dca.Sa - (Sa.Da - 2.Sca.Da).Dca.Sa.(Sa.Da - Dca.Sa) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // otherwise if 2.Sca > Sa and 4.Dca <= Da
-        //   Dca' = Dca.Sa + (2.Sca.Da - Sa.Da).((((16.Dsa.Sa - 12).Dsa.Sa + 4).Dsa.Da) - Dsa.Da) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // otherwise if 2.Sca > Sa and 4.Dca > Da
-        //   Dca' = Dca.Sa + (2.Sca.Da - Sa.Da).((Dca.Sa)^0.5 - Dca.Sa) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // 
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE double calc(double dca, double sca, double da, double sa, double sada, double d1a, double s1a)
-        {
-            double dcasa = dca * sa;
-            if (2 * sca <= sa) return dcasa - (sada - 2 * sca * da) * dcasa * (sada - dcasa) + sca * d1a + dca * s1a;
-            if (4 * dca <= da) return dcasa + (2 * sca * da - sada) * ((((16 * dcasa - 12) * dcasa + 4) * dca * da) - dca * da) + sca * d1a + dca * s1a;
-            return dcasa + (2 * sca * da - sada) * (sqrt(dcasa) - dcasa) + sca * d1a + dca * s1a;
-        }
-
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                if (d.a > 0)
-                {
-                    double sada = s.a * d.a;
-                    double s1a = 1 - s.a;
-                    double d1a = 1 - d.a;
-                    d.r = calc(d.r, s.r, d.a, s.a, sada, d1a, s1a);
-                    d.g = calc(d.g, s.g, d.a, s.a, sada, d1a, s1a);
-                    d.b = calc(d.b, s.b, d.a, s.a, sada, d1a, s1a);
-                    d.a += s.a - sada;
-                    set(p, clip(d));
-                }
-                else set(p, s);
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_difference
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_difference : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = Sca + Dca - 2.min(Sca.Da, Dca.Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                d.r += s.r - 2 * sd_min(s.r * d.a, d.r * s.a);
-                d.g += s.g - 2 * sd_min(s.g * d.a, d.g * s.a);
-                d.b += s.b - 2 * sd_min(s.b * d.a, d.b * s.a);
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-    //=====================================================comp_op_rgba_exclusion
-    template<class ColorT, class Order> 
-    struct comp_op_rgba_exclusion : blender_base<ColorT, Order>
-    {
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        using blender_base<ColorT, Order>::get;
-        using blender_base<ColorT, Order>::set;
-
-        // Dca' = (Sca.Da + Dca.Sa - 2.Sca.Dca) + Sca.(1 - Da) + Dca.(1 - Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            rgba s = get(r, g, b, a, cover);
-            if (s.a > 0)
-            {
-                rgba d = get(p);
-                double d1a = 1 - d.a;
-                double s1a = 1 - s.a;
-                d.r = (s.r * d.a + d.r * s.a - 2 * s.r * d.r) + s.r * d1a + d.r * s1a;
-                d.g = (s.g * d.a + d.g * s.a - 2 * s.g * d.g) + s.g * d1a + d.g * s1a;
-                d.b = (s.b * d.a + d.b * s.a - 2 * s.b * d.b) + s.b * d1a + d.b * s1a;
-                d.a += s.a - s.a * d.a;
-                set(p, clip(d));
-            }
-        }
-    };
-
-#if 0
-    //=====================================================comp_op_rgba_contrast
-    template<class ColorT, class Order> struct comp_op_rgba_contrast
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        { 
-            base_shift = color_type::base_shift,
-            base_mask  = color_type::base_mask
-        };
-
-
-        static AGG_INLINE void blend_pix(value_type* p, 
-                                         unsigned sr, unsigned sg, unsigned sb, 
-                                         unsigned sa, unsigned cover)
-        {
-            if (cover < 255)
-            {
-                sr = (sr * cover + 255) >> 8;
-                sg = (sg * cover + 255) >> 8;
-                sb = (sb * cover + 255) >> 8;
-                sa = (sa * cover + 255) >> 8;
-            }
-            long_type dr = p[Order::R];
-            long_type dg = p[Order::G];
-            long_type db = p[Order::B];
-            int       da = p[Order::A];
-            long_type d2a = da >> 1;
-            unsigned s2a = sa >> 1;
-
-            int r = (int)((((dr - d2a) * int((sr - s2a)*2 + base_mask)) >> base_shift) + d2a); 
-            int g = (int)((((dg - d2a) * int((sg - s2a)*2 + base_mask)) >> base_shift) + d2a); 
-            int b = (int)((((db - d2a) * int((sb - s2a)*2 + base_mask)) >> base_shift) + d2a); 
-
-            r = (r < 0) ? 0 : r;
-            g = (g < 0) ? 0 : g;
-            b = (b < 0) ? 0 : b;
-
-            p[Order::R] = (value_type)((r > da) ? da : r);
-            p[Order::G] = (value_type)((g > da) ? da : g);
-            p[Order::B] = (value_type)((b > da) ? da : b);
-        }
-    };
-
-    //=====================================================comp_op_rgba_invert
-    template<class ColorT, class Order> struct comp_op_rgba_invert
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        { 
-            base_shift = color_type::base_shift,
-            base_mask  = color_type::base_mask
-        };
-
-        // Dca' = (Da - Dca) * Sa + Dca.(1 - Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-                                         unsigned sr, unsigned sg, unsigned sb, 
-                                         unsigned sa, unsigned cover)
-        {
-            sa = (sa * cover + 255) >> 8;
-            if (sa)
-            {
-                calc_type da = p[Order::A];
-                calc_type dr = ((da - p[Order::R]) * sa + base_mask) >> base_shift;
-                calc_type dg = ((da - p[Order::G]) * sa + base_mask) >> base_shift;
-                calc_type db = ((da - p[Order::B]) * sa + base_mask) >> base_shift;
-                calc_type s1a = base_mask - sa;
-                p[Order::R] = (value_type)(dr + ((p[Order::R] * s1a + base_mask) >> base_shift));
-                p[Order::G] = (value_type)(dg + ((p[Order::G] * s1a + base_mask) >> base_shift));
-                p[Order::B] = (value_type)(db + ((p[Order::B] * s1a + base_mask) >> base_shift));
-                p[Order::A] = (value_type)(sa + da - ((sa * da + base_mask) >> base_shift));
-            }
-        }
-    };
-
-    //=================================================comp_op_rgba_invert_rgb
-    template<class ColorT, class Order> struct comp_op_rgba_invert_rgb
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        { 
-            base_shift = color_type::base_shift,
-            base_mask  = color_type::base_mask
-        };
-
-        // Dca' = (Da - Dca) * Sca + Dca.(1 - Sa)
-        // Da'  = Sa + Da - Sa.Da 
-        static AGG_INLINE void blend_pix(value_type* p, 
-                                         unsigned sr, unsigned sg, unsigned sb, 
-                                         unsigned sa, unsigned cover)
-        {
-            if (cover < 255)
-            {
-                sr = (sr * cover + 255) >> 8;
-                sg = (sg * cover + 255) >> 8;
-                sb = (sb * cover + 255) >> 8;
-                sa = (sa * cover + 255) >> 8;
-            }
-            if (sa)
-            {
-                calc_type da = p[Order::A];
-                calc_type dr = ((da - p[Order::R]) * sr + base_mask) >> base_shift;
-                calc_type dg = ((da - p[Order::G]) * sg + base_mask) >> base_shift;
-                calc_type db = ((da - p[Order::B]) * sb + base_mask) >> base_shift;
-                calc_type s1a = base_mask - sa;
-                p[Order::R] = (value_type)(dr + ((p[Order::R] * s1a + base_mask) >> base_shift));
-                p[Order::G] = (value_type)(dg + ((p[Order::G] * s1a + base_mask) >> base_shift));
-                p[Order::B] = (value_type)(db + ((p[Order::B] * s1a + base_mask) >> base_shift));
-                p[Order::A] = (value_type)(sa + da - ((sa * da + base_mask) >> base_shift));
-            }
-        }
-    };
-#endif
-
-
-    //======================================================comp_op_table_rgba
-    template<class ColorT, class Order> struct comp_op_table_rgba
-    {
-        typedef typename ColorT::value_type value_type;
-        typedef typename ColorT::calc_type calc_type;
-        typedef void (*comp_op_func_type)(value_type* p, 
-                                          value_type cr, 
-                                          value_type cg, 
-                                          value_type cb,
-                                          value_type ca,
-                                          cover_type cover);
-        static comp_op_func_type g_comp_op_func[];
-    };
-
-    //==========================================================g_comp_op_func
-    template<class ColorT, class Order> 
-    typename comp_op_table_rgba<ColorT, Order>::comp_op_func_type
-    comp_op_table_rgba<ColorT, Order>::g_comp_op_func[] = 
-    {
-        comp_op_rgba_clear      <ColorT,Order>::blend_pix,
-        comp_op_rgba_src        <ColorT,Order>::blend_pix,
-        comp_op_rgba_dst        <ColorT,Order>::blend_pix,
-        comp_op_rgba_src_over   <ColorT,Order>::blend_pix,
-        comp_op_rgba_dst_over   <ColorT,Order>::blend_pix,
-        comp_op_rgba_src_in     <ColorT,Order>::blend_pix,
-        comp_op_rgba_dst_in     <ColorT,Order>::blend_pix,
-        comp_op_rgba_src_out    <ColorT,Order>::blend_pix,
-        comp_op_rgba_dst_out    <ColorT,Order>::blend_pix,
-        comp_op_rgba_src_atop   <ColorT,Order>::blend_pix,
-        comp_op_rgba_dst_atop   <ColorT,Order>::blend_pix,
-        comp_op_rgba_xor        <ColorT,Order>::blend_pix,
-        comp_op_rgba_plus       <ColorT,Order>::blend_pix,
-        //comp_op_rgba_minus      <ColorT,Order>::blend_pix,
-        comp_op_rgba_multiply   <ColorT,Order>::blend_pix,
-        comp_op_rgba_screen     <ColorT,Order>::blend_pix,
-        comp_op_rgba_overlay    <ColorT,Order>::blend_pix,
-        comp_op_rgba_darken     <ColorT,Order>::blend_pix,
-        comp_op_rgba_lighten    <ColorT,Order>::blend_pix,
-        comp_op_rgba_color_dodge<ColorT,Order>::blend_pix,
-        comp_op_rgba_color_burn <ColorT,Order>::blend_pix,
-        comp_op_rgba_hard_light <ColorT,Order>::blend_pix,
-        comp_op_rgba_soft_light <ColorT,Order>::blend_pix,
-        comp_op_rgba_difference <ColorT,Order>::blend_pix,
-        comp_op_rgba_exclusion  <ColorT,Order>::blend_pix,
-        //comp_op_rgba_contrast   <ColorT,Order>::blend_pix,
-        //comp_op_rgba_invert     <ColorT,Order>::blend_pix,
-        //comp_op_rgba_invert_rgb <ColorT,Order>::blend_pix,
-        0
-    };
-
-
-    //==============================================================comp_op_e
-    enum comp_op_e
-    {
-        comp_op_clear,         //----comp_op_clear
-        comp_op_src,           //----comp_op_src
-        comp_op_dst,           //----comp_op_dst
-        comp_op_src_over,      //----comp_op_src_over
-        comp_op_dst_over,      //----comp_op_dst_over
-        comp_op_src_in,        //----comp_op_src_in
-        comp_op_dst_in,        //----comp_op_dst_in
-        comp_op_src_out,       //----comp_op_src_out
-        comp_op_dst_out,       //----comp_op_dst_out
-        comp_op_src_atop,      //----comp_op_src_atop
-        comp_op_dst_atop,      //----comp_op_dst_atop
-        comp_op_xor,           //----comp_op_xor
-        comp_op_plus,          //----comp_op_plus
-        //comp_op_minus,         //----comp_op_minus
-        comp_op_multiply,      //----comp_op_multiply
-        comp_op_screen,        //----comp_op_screen
-        comp_op_overlay,       //----comp_op_overlay
-        comp_op_darken,        //----comp_op_darken
-        comp_op_lighten,       //----comp_op_lighten
-        comp_op_color_dodge,   //----comp_op_color_dodge
-        comp_op_color_burn,    //----comp_op_color_burn
-        comp_op_hard_light,    //----comp_op_hard_light
-        comp_op_soft_light,    //----comp_op_soft_light
-        comp_op_difference,    //----comp_op_difference
-        comp_op_exclusion,     //----comp_op_exclusion
-        //comp_op_contrast,      //----comp_op_contrast
-        //comp_op_invert,        //----comp_op_invert
-        //comp_op_invert_rgb,    //----comp_op_invert_rgb
-
-        end_of_comp_op_e
-    };
-
-
-
-
-
-
-
-    //====================================================comp_op_adaptor_rgba
-    template<class ColorT, class Order> 
-    struct comp_op_adaptor_rgba
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            comp_op_table_rgba<ColorT, Order>::g_comp_op_func[op](p, 
-                color_type::multiply(r, a), 
-                color_type::multiply(g, a), 
-                color_type::multiply(b, a), 
-                a, cover);
-        }
-    };
-
-    //=========================================comp_op_adaptor_clip_to_dst_rgba
-    template<class ColorT, class Order> 
-    struct comp_op_adaptor_clip_to_dst_rgba
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            r = color_type::multiply(r, a);
-            g = color_type::multiply(g, a);
-            b = color_type::multiply(b, a);
-            value_type da = p[Order::A];
-            comp_op_table_rgba<ColorT, Order>::g_comp_op_func[op](p, 
-                color_type::multiply(r, da), 
-                color_type::multiply(g, da), 
-                color_type::multiply(b, da), 
-                color_type::multiply(a, da), cover);
-        }
-    };
-
-    //================================================comp_op_adaptor_rgba_pre
-    template<class ColorT, class Order> 
-    struct comp_op_adaptor_rgba_pre
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            comp_op_table_rgba<ColorT, Order>::g_comp_op_func[op](p, r, g, b, a, cover);
-        }
-    };
-
-    //=====================================comp_op_adaptor_clip_to_dst_rgba_pre
-    template<class ColorT, class Order> 
-    struct comp_op_adaptor_clip_to_dst_rgba_pre
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            value_type da = p[Order::A];
-            comp_op_table_rgba<ColorT, Order>::g_comp_op_func[op](p, 
-                color_type::multiply(r, da), 
-                color_type::multiply(g, da), 
-                color_type::multiply(b, da), 
-                color_type::multiply(a, da), cover);
-        }
-    };
-
-    //====================================================comp_op_adaptor_rgba_plain
-    template<class ColorT, class Order> 
-    struct comp_op_adaptor_rgba_plain
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            multiplier_rgba<ColorT, Order>::premultiply(p);
-            comp_op_adaptor_rgba<ColorT, Order>::blend_pix(op, p, r, g, b, a, cover);
-            multiplier_rgba<ColorT, Order>::demultiply(p);
-        }
-    };
-
-    //=========================================comp_op_adaptor_clip_to_dst_rgba_plain
-    template<class ColorT, class Order> 
-    struct comp_op_adaptor_clip_to_dst_rgba_plain
-    {
-        typedef ColorT color_type;
-        typedef Order order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            multiplier_rgba<ColorT, Order>::premultiply(p);
-            comp_op_adaptor_clip_to_dst_rgba<ColorT, Order>::blend_pix(op, p, r, g, b, a, cover);
-            multiplier_rgba<ColorT, Order>::demultiply(p);
-        }
-    };
-
-    //=======================================================comp_adaptor_rgba
-    template<class BlenderPre> 
-    struct comp_adaptor_rgba
-    {
-        typedef typename BlenderPre::color_type color_type;
-        typedef typename BlenderPre::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            BlenderPre::blend_pix(p, 
-                color_type::multiply(r, a), 
-                color_type::multiply(g, a), 
-                color_type::multiply(b, a), 
-                a, cover);
-        }
-    };
-
-    //==========================================comp_adaptor_clip_to_dst_rgba
-    template<class BlenderPre> 
-    struct comp_adaptor_clip_to_dst_rgba
-    {
-        typedef typename BlenderPre::color_type color_type;
-        typedef typename BlenderPre::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            r = color_type::multiply(r, a);
-            g = color_type::multiply(g, a);
-            b = color_type::multiply(b, a);
-            value_type da = p[order_type::A];
-            BlenderPre::blend_pix(p, 
-                color_type::multiply(r, da), 
-                color_type::multiply(g, da), 
-                color_type::multiply(b, da), 
-                color_type::multiply(a, da), cover);
-        }
-    };
-
-    //=======================================================comp_adaptor_rgba_pre
-    template<class BlenderPre> 
-    struct comp_adaptor_rgba_pre
-    {
-        typedef typename BlenderPre::color_type color_type;
-        typedef typename BlenderPre::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            BlenderPre::blend_pix(p, r, g, b, a, cover);
-        }
-    };
-
-    //======================================comp_adaptor_clip_to_dst_rgba_pre
-    template<class BlenderPre> 
-    struct comp_adaptor_clip_to_dst_rgba_pre
-    {
-        typedef typename BlenderPre::color_type color_type;
-        typedef typename BlenderPre::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            unsigned da = p[order_type::A];
-            BlenderPre::blend_pix(p, 
-                color_type::multiply(r, da), 
-                color_type::multiply(g, da), 
-                color_type::multiply(b, da), 
-                color_type::multiply(a, da), 
-                cover);
-        }
-    };
-
-    //=======================================================comp_adaptor_rgba_plain
-    template<class BlenderPre> 
-    struct comp_adaptor_rgba_plain
-    {
-        typedef typename BlenderPre::color_type color_type;
-        typedef typename BlenderPre::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            multiplier_rgba<color_type, order_type>::premultiply(p);
-            comp_adaptor_rgba<BlenderPre>::blend_pix(op, p, r, g, b, a, cover);
-            multiplier_rgba<color_type, order_type>::demultiply(p);
-        }
-    };
-
-    //==========================================comp_adaptor_clip_to_dst_rgba_plain
-    template<class BlenderPre> 
-    struct comp_adaptor_clip_to_dst_rgba_plain
-    {
-        typedef typename BlenderPre::color_type color_type;
-        typedef typename BlenderPre::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        static AGG_INLINE void blend_pix(unsigned op, value_type* p, 
-            value_type r, value_type g, value_type b, value_type a, cover_type cover)
-        {
-            multiplier_rgba<color_type, order_type>::premultiply(p);
-            comp_adaptor_clip_to_dst_rgba<BlenderPre>::blend_pix(op, p, r, g, b, a, cover);
-            multiplier_rgba<color_type, order_type>::demultiply(p);
-        }
-    };
-
-
-    //=================================================pixfmt_alpha_blend_rgba
-    template<class Blender, class RenBuf> 
-    class pixfmt_alpha_blend_rgba
-    {
-    public:
-        typedef pixfmt_rgba_tag pixfmt_category;
-        typedef RenBuf   rbuf_type;
-        typedef typename rbuf_type::row_data row_data;
-        typedef Blender  blender_type;
-        typedef typename blender_type::color_type color_type;
-        typedef typename blender_type::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        enum 
-        {
-            num_components = 4,
-            pix_step = 4,
-            pix_width = sizeof(value_type) * pix_step,
-        };
-        struct pixel_type
-        {
-            value_type c[num_components];
-
-            void set(value_type r, value_type g, value_type b, value_type a)
-            {
-                c[order_type::R] = r;
-                c[order_type::G] = g;
-                c[order_type::B] = b;
-                c[order_type::A] = a;
-            }
-
-            void set(const color_type& color)
-            {
-                set(color.r, color.g, color.b, color.a);
-            }
-
-            void get(value_type& r, value_type& g, value_type& b, value_type& a) const
-            {
-                r = c[order_type::R];
-                g = c[order_type::G];
-                b = c[order_type::B];
-                a = c[order_type::A];
-            }
-
-            color_type get() const
-            {
-                return color_type(
-                    c[order_type::R], 
-                    c[order_type::G], 
-                    c[order_type::B],
-                    c[order_type::A]);
-            }
-
-            pixel_type* next()
-            {
-                return (pixel_type*)(c + pix_step);
-            }
-
-            const pixel_type* next() const
-            {
-                return (const pixel_type*)(c + pix_step);
-            }
-
-            pixel_type* advance(int n)
-            {
-                return (pixel_type*)(c + n * pix_step);
-            }
-
-            const pixel_type* advance(int n) const
-            {
-                return (const pixel_type*)(c + n * pix_step);
-            }
-        };
-
-    private:
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c, unsigned cover)
-        {
-            m_blender.blend_pix(p->c, c.r, c.g, c.b, c.a, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c)
-        {
-            m_blender.blend_pix(p->c, c.r, c.g, c.b, c.a);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c, unsigned cover)
-        {
-            if (!c.is_transparent())
-            {
-                if (c.is_opaque() && cover == cover_mask)
-                {
-                    p->set(c.r, c.g, c.b, c.a);
-                }
-                else
-                {
-                    m_blender.blend_pix(p->c, c.r, c.g, c.b, c.a, cover);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c)
-        {
-            if (!c.is_transparent())
-            {
-                if (c.is_opaque())
-                {
-                    p->set(c.r, c.g, c.b, c.a);
-                }
-                else
-                {
-                    m_blender.blend_pix(p->c, c.r, c.g, c.b, c.a);
-                }
-            }
-        }
-
-    public:
-        //--------------------------------------------------------------------
-        pixfmt_alpha_blend_rgba() : m_rbuf(0) {}
-        explicit pixfmt_alpha_blend_rgba(rbuf_type& rb) : m_rbuf(&rb) {}
-        void attach(rbuf_type& rb) { m_rbuf = &rb; }
-
-        //--------------------------------------------------------------------
-        template<class PixFmt>
-        bool attach(PixFmt& pixf, int x1, int y1, int x2, int y2)
-        {
-            rect_i r(x1, y1, x2, y2);
-            if (r.clip(rect_i(0, 0, pixf.width()-1, pixf.height()-1)))
-            {
-                int stride = pixf.stride();
-                m_rbuf->attach(pixf.pix_ptr(r.x1, stride < 0 ? r.y2 : r.y1), 
-                               (r.x2 - r.x1) + 1,
-                               (r.y2 - r.y1) + 1,
-                               stride);
-                return true;
-            }
-            return false;
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE unsigned width()  const { return m_rbuf->width();  }
-        AGG_INLINE unsigned height() const { return m_rbuf->height(); }
-        AGG_INLINE int      stride() const { return m_rbuf->stride(); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE       int8u* row_ptr(int y)       { return m_rbuf->row_ptr(y); }
-        AGG_INLINE const int8u* row_ptr(int y) const { return m_rbuf->row_ptr(y); }
-        AGG_INLINE row_data     row(int y)     const { return m_rbuf->row(y); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE int8u* pix_ptr(int x, int y) 
-        { 
-            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step);
-        }
-
-        AGG_INLINE const int8u* pix_ptr(int x, int y) const 
-        { 
-            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step);
-        }
-
-        // Return pointer to pixel value, forcing row to be allocated.
-        AGG_INLINE pixel_type* pix_value_ptr(int x, int y, unsigned len) 
-        {
-            return (pixel_type*)(m_rbuf->row_ptr(x, y, len) + sizeof(value_type) * (x * pix_step));
-        }
-
-        // Return pointer to pixel value, or null if row not allocated.
-        AGG_INLINE const pixel_type* pix_value_ptr(int x, int y) const 
-        {
-            int8u* p = m_rbuf->row_ptr(y);
-            return p ? (pixel_type*)(p + sizeof(value_type) * (x * pix_step)) : 0;
-        }
-
-        // Get pixel pointer from raw buffer pointer.
-        AGG_INLINE static pixel_type* pix_value_ptr(void* p) 
-        {
-            return (pixel_type*)p;
-        }
-
-        // Get pixel pointer from raw buffer pointer.
-        AGG_INLINE static const pixel_type* pix_value_ptr(const void* p) 
-        {
-            return (const pixel_type*)p;
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE static void write_plain_color(void* p, color_type c)
-        {
-            blender_type::set_plain_color(pix_value_ptr(p)->c, c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE static color_type read_plain_color(const void* p)
-        {
-            return blender_type::get_plain_color(pix_value_ptr(p)->c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE static void make_pix(int8u* p, const color_type& c)
-        {
-            ((pixel_type*)p)->set(c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE color_type pixel(int x, int y) const
-        {
-            if (const pixel_type* p = pix_value_ptr(x, y))
-            {
-                return p->get();
-            }
-            return color_type::no_color();
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_pixel(int x, int y, const color_type& c)
-        {
-            pix_value_ptr(x, y, 1)->set(c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pixel(int x, int y, const color_type& c, int8u cover)
-        {
-            copy_or_blend_pix(pix_value_ptr(x, y, 1), c, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_hline(int x, int y, 
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            pixel_type v;
-            v.set(c);
-            pixel_type* p = pix_value_ptr(x, y, len);
-            do
-            {
-                *p = v;
-                p = p->next();
-            }
-            while (--len);
-        }
-
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_vline(int x, int y,
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            pixel_type v;
-            v.set(c);
-            do
-            {
-                *pix_value_ptr(x, y++, 1) = v;
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_hline(int x, int y,
-                         unsigned len, 
-                         const color_type& c,
-                         int8u cover)
-        {
-            if (!c.is_transparent())
-            {
-                pixel_type* p = pix_value_ptr(x, y, len);
-                if (c.is_opaque() && cover == cover_mask)
-                {
-                    pixel_type v;
-                    v.set(c);
-                    do
-                    {
-                        *p = v;
-                        p = p->next();
-                    }
-                    while (--len);
-                }
-                else
-                {
-                    if (cover == cover_mask)
-                    {
-                        do
-                        {
-                            blend_pix(p, c);
-                            p = p->next();
-                        }
-                        while (--len);
-                    }
-                    else
-                    {
-                        do
-                        {
-                            blend_pix(p, c, cover);
-                            p = p->next();
-                        }
-                        while (--len);
-                    }
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void blend_vline(int x, int y,
-                         unsigned len, 
-                         const color_type& c,
-                         int8u cover)
-        {
-            if (!c.is_transparent())
-            {
-                if (c.is_opaque() && cover == cover_mask)
-                {
-                    pixel_type v;
-                    v.set(c);
-                    do
-                    {
-                        *pix_value_ptr(x, y++, 1) = v;
-                    }
-                    while (--len);
-                }
-                else
-                {
-                    if (cover == cover_mask)
-                    {
-                        do
-                        {
-                            blend_pix(pix_value_ptr(x, y++, 1), c, c.a);
-                        }
-                        while (--len);
-                    }
-                    else
-                    {
-                        do
-                        {
-                            blend_pix(pix_value_ptr(x, y++, 1), c, cover);
-                        }
-                        while (--len);
-                    }
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void blend_solid_hspan(int x, int y,
-                               unsigned len, 
-                               const color_type& c,
-                               const int8u* covers)
-        {
-            if (!c.is_transparent())
-            {
-                pixel_type* p = pix_value_ptr(x, y, len);
-                do 
-                {
-                    if (c.is_opaque() && *covers == cover_mask)
-                    {
-                        p->set(c);
-                    }
-                    else
-                    {
-                        blend_pix(p, c, *covers);
-                    }
-                    p = p->next();
-                    ++covers;
-                }
-                while (--len);
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void blend_solid_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type& c,
-                               const int8u* covers)
-        {
-            if (!c.is_transparent())
-            {
-                do 
-                {
-                    pixel_type* p = pix_value_ptr(x, y++, 1);
-                    if (c.is_opaque() && *covers == cover_mask)
-                    {
-                        p->set(c);
-                    }
-                    else
-                    {
-                        blend_pix(p, c, *covers);
-                    }
-                    ++covers;
-                }
-                while (--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void copy_color_hspan(int x, int y,
-                              unsigned len, 
-                              const color_type* colors)
-        {
-            pixel_type* p = pix_value_ptr(x, y, len);
-            do 
-            {
-                p->set(*colors++);
-                p = p->next();
-            }
-            while (--len);
-        }
-
-
-        //--------------------------------------------------------------------
-        void copy_color_vspan(int x, int y,
-                              unsigned len, 
-                              const color_type* colors)
-        {
-            do 
-            {
-                pix_value_ptr(x, y++, 1)->set(*colors++);
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_hspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const int8u* covers,
-                               int8u cover)
-        {
-            pixel_type* p = pix_value_ptr(x, y, len);
-            if (covers)
-            {
-                do 
-                {
-                    copy_or_blend_pix(p, *colors++, *covers++);
-                    p = p->next();
-                }
-                while (--len);
-            }
-            else
-            {
-                if (cover == cover_mask)
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(p, *colors++);
-                        p = p->next();
-                    }
-                    while (--len);
-                }
-                else
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(p, *colors++, cover);
-                        p = p->next();
-                    }
-                    while (--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const int8u* covers,
-                               int8u cover)
-        {
-            if (covers)
-            {
-                do 
-                {
-                    copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++, *covers++);
-                }
-                while (--len);
-            }
-            else
-            {
-                if (cover == cover_mask)
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++);
-                    }
-                    while (--len);
-                }
-                else
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(pix_value_ptr(x, y++, 1), *colors++, cover);
-                    }
-                    while (--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        template<class Function> void for_each_pixel(Function f)
-        {
-            for (unsigned y = 0; y < height(); ++y)
-            {
-                row_data r = m_rbuf->row(y);
-                if (r.ptr)
-                {
-                    unsigned len = r.x2 - r.x1 + 1;
-                    pixel_type* p = pix_value_ptr(r.x1, y, len);
-                    do
-                    {
-                        f(p->c);
-                        p = p->next();
-                    }
-                    while (--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void premultiply()
-        {
-            for_each_pixel(multiplier_rgba<color_type, order_type>::premultiply);
-        }
-
-        //--------------------------------------------------------------------
-        void demultiply()
-        {
-            for_each_pixel(multiplier_rgba<color_type, order_type>::demultiply);
-        }
-
-        //--------------------------------------------------------------------
-        template<class GammaLut> void apply_gamma_dir(const GammaLut& g)
-        {
-            for_each_pixel(apply_gamma_dir_rgba<color_type, order_type, GammaLut>(g));
-        }
-
-        //--------------------------------------------------------------------
-        template<class GammaLut> void apply_gamma_inv(const GammaLut& g)
-        {
-            for_each_pixel(apply_gamma_inv_rgba<color_type, order_type, GammaLut>(g));
-        }
-
-        //--------------------------------------------------------------------
-        template<class RenBuf2> void copy_from(const RenBuf2& from, 
-                                               int xdst, int ydst,
-                                               int xsrc, int ysrc,
-                                               unsigned len)
-        {
-            if (const int8u* p = from.row_ptr(ysrc))
-            {
-                memmove(m_rbuf->row_ptr(xdst, ydst, len) + xdst * pix_width, 
-                        p + xsrc * pix_width, 
-                        len * pix_width);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Blend from another RGBA surface.
-        template<class SrcPixelFormatRenderer>
-        void blend_from(const SrcPixelFormatRenderer& from, 
-                        int xdst, int ydst,
-                        int xsrc, int ysrc,
-                        unsigned len,
-                        int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
-
-            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
-            {
-                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
-                int srcinc = 1;
-                int dstinc = 1;
-
-                if (xdst > xsrc)
-                {
-                    psrc = psrc->advance(len - 1);
-                    pdst = pdst->advance(len - 1);
-                    srcinc = -1;
-                    dstinc = -1;
-                }
-
-                if (cover == cover_mask)
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(pdst, psrc->get());
-                        psrc = psrc->advance(srcinc);
-                        pdst = pdst->advance(dstinc);
-                    }
-                    while (--len);
-                }
-                else
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(pdst, psrc->get(), cover);
-                        psrc = psrc->advance(srcinc);
-                        pdst = pdst->advance(dstinc);
-                    }
-                    while (--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Combine single color with grayscale surface and blend.
-        template<class SrcPixelFormatRenderer>
-        void blend_from_color(const SrcPixelFormatRenderer& from, 
-                              const color_type& color,
-                              int xdst, int ydst,
-                              int xsrc, int ysrc,
-                              unsigned len,
-                              int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
-            typedef typename SrcPixelFormatRenderer::color_type src_color_type;
-
-            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
-            {
-                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
-
-                do 
-                {
-                    copy_or_blend_pix(pdst, color, 
-                        src_color_type::scale_cover(cover, psrc->c[0]));
-                    psrc = psrc->next();
-                    pdst = pdst->next();
-                }
-                while (--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Blend from color table, using grayscale surface as indexes into table.
-        // Obviously, this only works for integer value types.
-        template<class SrcPixelFormatRenderer>
-        void blend_from_lut(const SrcPixelFormatRenderer& from, 
-                            const color_type* color_lut,
-                            int xdst, int ydst,
-                            int xsrc, int ysrc,
-                            unsigned len,
-                            int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
-
-            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
-            {
-                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
-
-                if (cover == cover_mask)
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(pdst, color_lut[psrc->c[0]]);
-                        psrc = psrc->next();
-                        pdst = pdst->next();
-                    }
-                    while (--len);
-                }
-                else
-                {
-                    do 
-                    {
-                        copy_or_blend_pix(pdst, color_lut[psrc->c[0]], cover);
-                        psrc = psrc->next();
-                        pdst = pdst->next();
-                    }
-                    while (--len);
-                }
-            }
-        }
-
-    private:
-        rbuf_type* m_rbuf;
-        Blender    m_blender;
-    };
-
-    //================================================pixfmt_custom_blend_rgba
-    template<class Blender, class RenBuf> class pixfmt_custom_blend_rgba
-    {
-    public:
-        typedef pixfmt_rgba_tag pixfmt_category;
-        typedef RenBuf   rbuf_type;
-        typedef typename rbuf_type::row_data row_data;
-        typedef Blender  blender_type;
-        typedef typename blender_type::color_type color_type;
-        typedef typename blender_type::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        enum 
-        {
-            num_components = 4,
-            pix_step = 4,
-            pix_width  = sizeof(value_type) * pix_step,
-        };
-        struct pixel_type
-        {
-            value_type c[num_components];
-
-            void set(value_type r, value_type g, value_type b, value_type a)
-            {
-                c[order_type::R] = r;
-                c[order_type::G] = g;
-                c[order_type::B] = b;
-                c[order_type::A] = a;
-            }
-
-            void set(const color_type& color)
-            {
-                set(color.r, color.g, color.b, color.a);
-            }
-
-            void get(value_type& r, value_type& g, value_type& b, value_type& a) const
-            {
-                r = c[order_type::R];
-                g = c[order_type::G];
-                b = c[order_type::B];
-                a = c[order_type::A];
-            }
-
-            color_type get() const
-            {
-                return color_type(
-                    c[order_type::R], 
-                    c[order_type::G], 
-                    c[order_type::B],
-                    c[order_type::A]);
-            }
-
-            pixel_type* next()
-            {
-                return (pixel_type*)(c + pix_step);
-            }
-
-            const pixel_type* next() const
-            {
-                return (const pixel_type*)(c + pix_step);
-            }
-
-            pixel_type* advance(int n)
-            {
-                return (pixel_type*)(c + n * pix_step);
-            }
-
-            const pixel_type* advance(int n) const
-            {
-                return (const pixel_type*)(c + n * pix_step);
-            }
-        };
-
-
-    private:
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pix(pixel_type* p, const color_type& c, unsigned cover = cover_full)
-        {
-            m_blender.blend_pix(m_comp_op, p->c, c.r, c.g, c.b, c.a, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_or_blend_pix(pixel_type* p, const color_type& c, unsigned cover = cover_full)
-        {
-            if (!c.is_transparent())
-            {
-                if (c.is_opaque() && cover == cover_mask)
-                {
-                    p->set(c.r, c.g, c.b, c.a);
-                }
-                else
-                {
-                    blend_pix(p, c, cover);
-                }
-            }
-        }
-
-    public:
-        //--------------------------------------------------------------------
-        pixfmt_custom_blend_rgba() : m_rbuf(0), m_comp_op(3) {}
-        explicit pixfmt_custom_blend_rgba(rbuf_type& rb, unsigned comp_op=3) : 
-            m_rbuf(&rb),
-            m_comp_op(comp_op)
-        {}
-        void attach(rbuf_type& rb) { m_rbuf = &rb; }
-
-        //--------------------------------------------------------------------
-        template<class PixFmt>
-        bool attach(PixFmt& pixf, int x1, int y1, int x2, int y2)
-        {
-            rect_i r(x1, y1, x2, y2);
-            if (r.clip(rect_i(0, 0, pixf.width()-1, pixf.height()-1)))
-            {
-                int stride = pixf.stride();
-                m_rbuf->attach(pixf.pix_ptr(r.x1, stride < 0 ? r.y2 : r.y1), 
-                               (r.x2 - r.x1) + 1,
-                               (r.y2 - r.y1) + 1,
-                               stride);
-                return true;
-            }
-            return false;
-        }
-
-        //--------------------------------------------------------------------
-        void comp_op(unsigned op) { m_comp_op = op; }
-        unsigned comp_op() const  { return m_comp_op; }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE unsigned width()  const { return m_rbuf->width();  }
-        AGG_INLINE unsigned height() const { return m_rbuf->height(); }
-        AGG_INLINE int      stride() const { return m_rbuf->stride(); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE       int8u* row_ptr(int y)       { return m_rbuf->row_ptr(y); }
-        AGG_INLINE const int8u* row_ptr(int y) const { return m_rbuf->row_ptr(y); }
-        AGG_INLINE row_data     row(int y)     const { return m_rbuf->row(y); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE int8u* pix_ptr(int x, int y) 
-        { 
-            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step);
-        }
-
-        AGG_INLINE const int8u* pix_ptr(int x, int y) const 
-        { 
-            return m_rbuf->row_ptr(y) + sizeof(value_type) * (x * pix_step);
-        }
-
-        // Return pointer to pixel value, forcing row to be allocated.
-        AGG_INLINE pixel_type* pix_value_ptr(int x, int y, unsigned len) 
-        {
-            return (pixel_type*)(m_rbuf->row_ptr(x, y, len) + sizeof(value_type) * (x * pix_step));
-        }
-
-        // Return pointer to pixel value, or null if row not allocated.
-        AGG_INLINE const pixel_type* pix_value_ptr(int x, int y) const 
-        {
-            int8u* p = m_rbuf->row_ptr(y);
-            return p ? (pixel_type*)(p + sizeof(value_type) * (x * pix_step)) : 0;
-        }
-
-        // Get pixel pointer from raw buffer pointer.
-        AGG_INLINE static pixel_type* pix_value_ptr(void* p) 
-        {
-            return (pixel_type*)p;
-        }
-
-        // Get pixel pointer from raw buffer pointer.
-        AGG_INLINE static const pixel_type* pix_value_ptr(const void* p) 
-        {
-            return (const pixel_type*)p;
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE static void make_pix(int8u* p, const color_type& c)
-        {
-            ((pixel_type*)p)->set(c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE color_type pixel(int x, int y) const
-        {
-            if (const pixel_type* p = pix_value_ptr(x, y))
-            {
-                return p->get();
-            }
-            return color_type::no_color();
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_pixel(int x, int y, const color_type& c)
-        {
-            make_pix(pix_value_ptr(x, y, 1), c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pixel(int x, int y, const color_type& c, int8u cover)
-        {
-            blend_pix(pix_value_ptr(x, y, 1), c, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_hline(int x, int y, 
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            pixel_type v;
-            v.set(c);
-            pixel_type* p = pix_value_ptr(x, y, len);
-            do
-            {
-                *p = v;
-                p = p->next();
-            }
-            while (--len);
-        }
-
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_vline(int x, int y,
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            pixel_type v;
-            v.set(c);
-            do
-            {
-                *pix_value_ptr(x, y++, 1) = v;
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_hline(int x, int y, unsigned len, 
-                         const color_type& c, int8u cover)
-        {
-
-            pixel_type* p = pix_value_ptr(x, y, len);
-            do
-            {
-                blend_pix(p, c, cover);
-                p = p->next();
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_vline(int x, int y, unsigned len, 
-                         const color_type& c, int8u cover)
-        {
-            do
-            {
-                blend_pix(pix_value_ptr(x, y++, 1), c, cover);
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_solid_hspan(int x, int y, unsigned len, 
-                               const color_type& c, const int8u* covers)
-        {
-            pixel_type* p = pix_value_ptr(x, y, len);
-
-            do 
-            {
-                blend_pix(p, c, *covers++);
-                p = p->next();
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_solid_vspan(int x, int y, unsigned len, 
-                               const color_type& c, const int8u* covers)
-        {
-            do 
-            {
-                blend_pix(pix_value_ptr(x, y++, 1), c, *covers++);
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_color_hspan(int x, int y,
-                              unsigned len, 
-                              const color_type* colors)
-        {
-            pixel_type* p = pix_value_ptr(x, y, len);
-
-            do 
-            {
-                p->set(*colors++);
-                p = p->next();
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void copy_color_vspan(int x, int y,
-                              unsigned len, 
-                              const color_type* colors)
-        {
-            do 
-            {
-                pix_value_ptr(x, y++, 1)->set(*colors++);
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_hspan(int x, int y, unsigned len, 
-                               const color_type* colors, 
-                               const int8u* covers,
-                               int8u cover)
-        {
-            pixel_type* p = pix_value_ptr(x, y, len);
-
-            do 
-            {
-                blend_pix(p, *colors++, covers ? *covers++ : cover);
-                p = p->next();
-            }
-            while (--len);
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_vspan(int x, int y, unsigned len, 
-                               const color_type* colors, 
-                               const int8u* covers,
-                               int8u cover)
-        {
-            do 
-            {
-                blend_pix(pix_value_ptr(x, y++, 1), *colors++, covers ? *covers++ : cover);
-            }
-            while (--len);
-
-        }
-
-        //--------------------------------------------------------------------
-        template<class Function> void for_each_pixel(Function f)
-        {
-            unsigned y;
-            for (y = 0; y < height(); ++y)
-            {
-                row_data r = m_rbuf->row(y);
-                if (r.ptr)
-                {
-                    unsigned len = r.x2 - r.x1 + 1;
-                    pixel_type* p = pix_value_ptr(r.x1, y, len);
-                    do
-                    {
-                        f(p->c);
-                        p = p->next();
-                    }
-                    while (--len);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void premultiply()
-        {
-            for_each_pixel(multiplier_rgba<color_type, order_type>::premultiply);
-        }
-
-        //--------------------------------------------------------------------
-        void demultiply()
-        {
-            for_each_pixel(multiplier_rgba<color_type, order_type>::demultiply);
-        }
-
-        //--------------------------------------------------------------------
-        template<class GammaLut> void apply_gamma_dir(const GammaLut& g)
-        {
-            for_each_pixel(apply_gamma_dir_rgba<color_type, order_type, GammaLut>(g));
-        }
-
-        //--------------------------------------------------------------------
-        template<class GammaLut> void apply_gamma_inv(const GammaLut& g)
-        {
-            for_each_pixel(apply_gamma_inv_rgba<color_type, order_type, GammaLut>(g));
-        }
-
-        //--------------------------------------------------------------------
-        template<class RenBuf2> void copy_from(const RenBuf2& from, 
-                                               int xdst, int ydst,
-                                               int xsrc, int ysrc,
-                                               unsigned len)
-        {
-            if (const int8u* p = from.row_ptr(ysrc))
-            {
-                memmove(m_rbuf->row_ptr(xdst, ydst, len) + xdst * pix_width, 
-                        p + xsrc * pix_width, 
-                        len * pix_width);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Blend from another RGBA surface.
-        template<class SrcPixelFormatRenderer> 
-        void blend_from(const SrcPixelFormatRenderer& from, 
-                        int xdst, int ydst,
-                        int xsrc, int ysrc,
-                        unsigned len,
-                        int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
-
-            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
-            {
-                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
-                int srcinc = 1;
-                int dstinc = 1;
-
-                if (xdst > xsrc)
-                {
-                    psrc = psrc->advance(len - 1);
-                    pdst = pdst->advance(len - 1);
-                    srcinc = -1;
-                    dstinc = -1;
-                }
-
-                do 
-                {
-                    blend_pix(pdst, psrc->get(), cover);
-                    psrc = psrc->advance(srcinc);
-                    pdst = pdst->advance(dstinc);
-                }
-                while (--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Blend from single color, using grayscale surface as alpha channel.
-        template<class SrcPixelFormatRenderer>
-        void blend_from_color(const SrcPixelFormatRenderer& from, 
-                              const color_type& color,
-                              int xdst, int ydst,
-                              int xsrc, int ysrc,
-                              unsigned len,
-                              int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
-            typedef typename SrcPixelFormatRenderer::color_type src_color_type;
-
-            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
-            {
-                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
-
-                do 
-                {
-                    blend_pix(pdst, color,
-                        src_color_type::scale_cover(cover, psrc->c[0]));
-                    psrc = psrc->next();
-                    pdst = pdst->next();
-                }
-                while (--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Blend from color table, using grayscale surface as indexes into table.
-        // Obviously, this only works for integer value types.
-        template<class SrcPixelFormatRenderer>
-        void blend_from_lut(const SrcPixelFormatRenderer& from, 
-                            const color_type* color_lut,
-                            int xdst, int ydst,
-                            int xsrc, int ysrc,
-                            unsigned len,
-                            int8u cover)
-        {
-            typedef typename SrcPixelFormatRenderer::pixel_type src_pixel_type;
-
-            if (const src_pixel_type* psrc = from.pix_value_ptr(xsrc, ysrc))
-            {
-                pixel_type* pdst = pix_value_ptr(xdst, ydst, len);
-
-                do 
-                {
-                    blend_pix(pdst, color_lut[psrc->c[0]], cover);
-                    psrc = psrc->next();
-                    pdst = pdst->next();
-                }
-                while (--len);
-            }
-        }
-
-    private:
-        rbuf_type* m_rbuf;
-        Blender m_blender;
-        unsigned m_comp_op;
-    };
-
-
-    //-----------------------------------------------------------------------
-    typedef blender_rgba<rgba8, order_rgba> blender_rgba32;
-    typedef blender_rgba<rgba8, order_argb> blender_argb32;
-    typedef blender_rgba<rgba8, order_abgr> blender_abgr32;
-    typedef blender_rgba<rgba8, order_bgra> blender_bgra32;
-
-    typedef blender_rgba<srgba8, order_rgba> blender_srgba32;
-    typedef blender_rgba<srgba8, order_argb> blender_sargb32;
-    typedef blender_rgba<srgba8, order_abgr> blender_sabgr32;
-    typedef blender_rgba<srgba8, order_bgra> blender_sbgra32;
-
-    typedef blender_rgba_pre<rgba8, order_rgba> blender_rgba32_pre;
-    typedef blender_rgba_pre<rgba8, order_argb> blender_argb32_pre;
-    typedef blender_rgba_pre<rgba8, order_abgr> blender_abgr32_pre;
-    typedef blender_rgba_pre<rgba8, order_bgra> blender_bgra32_pre;
-
-    typedef blender_rgba_pre<srgba8, order_rgba> blender_srgba32_pre;
-    typedef blender_rgba_pre<srgba8, order_argb> blender_sargb32_pre;
-    typedef blender_rgba_pre<srgba8, order_abgr> blender_sabgr32_pre;
-    typedef blender_rgba_pre<srgba8, order_bgra> blender_sbgra32_pre;
-
-    typedef blender_rgba_plain<rgba8, order_rgba> blender_rgba32_plain;
-    typedef blender_rgba_plain<rgba8, order_argb> blender_argb32_plain;
-    typedef blender_rgba_plain<rgba8, order_abgr> blender_abgr32_plain;
-    typedef blender_rgba_plain<rgba8, order_bgra> blender_bgra32_plain;
-
-    typedef blender_rgba_plain<srgba8, order_rgba> blender_srgba32_plain;
-    typedef blender_rgba_plain<srgba8, order_argb> blender_sargb32_plain;
-    typedef blender_rgba_plain<srgba8, order_abgr> blender_sabgr32_plain;
-    typedef blender_rgba_plain<srgba8, order_bgra> blender_sbgra32_plain;
-
-    typedef blender_rgba<rgba16, order_rgba> blender_rgba64;
-    typedef blender_rgba<rgba16, order_argb> blender_argb64;
-    typedef blender_rgba<rgba16, order_abgr> blender_abgr64;
-    typedef blender_rgba<rgba16, order_bgra> blender_bgra64;
-
-    typedef blender_rgba_pre<rgba16, order_rgba> blender_rgba64_pre;
-    typedef blender_rgba_pre<rgba16, order_argb> blender_argb64_pre;
-    typedef blender_rgba_pre<rgba16, order_abgr> blender_abgr64_pre;
-    typedef blender_rgba_pre<rgba16, order_bgra> blender_bgra64_pre;
-
-	typedef blender_rgba_plain<rgba16, order_rgba> blender_rgba64_plain;
-	typedef blender_rgba_plain<rgba16, order_argb> blender_argb64_plain;
-	typedef blender_rgba_plain<rgba16, order_abgr> blender_abgr64_plain;
-	typedef blender_rgba_plain<rgba16, order_bgra> blender_bgra64_plain;
-
-	typedef blender_rgba<rgba32, order_rgba> blender_rgba128;
-    typedef blender_rgba<rgba32, order_argb> blender_argb128;
-    typedef blender_rgba<rgba32, order_abgr> blender_abgr128;
-    typedef blender_rgba<rgba32, order_bgra> blender_bgra128;
-
-    typedef blender_rgba_pre<rgba32, order_rgba> blender_rgba128_pre;
-    typedef blender_rgba_pre<rgba32, order_argb> blender_argb128_pre;
-    typedef blender_rgba_pre<rgba32, order_abgr> blender_abgr128_pre;
-    typedef blender_rgba_pre<rgba32, order_bgra> blender_bgra128_pre;
-
-    typedef blender_rgba_plain<rgba32, order_rgba> blender_rgba128_plain;
-    typedef blender_rgba_plain<rgba32, order_argb> blender_argb128_plain;
-    typedef blender_rgba_plain<rgba32, order_abgr> blender_abgr128_plain;
-    typedef blender_rgba_plain<rgba32, order_bgra> blender_bgra128_plain;
-
-
-    //-----------------------------------------------------------------------
-    typedef pixfmt_alpha_blend_rgba<blender_rgba32, rendering_buffer> pixfmt_rgba32;
-    typedef pixfmt_alpha_blend_rgba<blender_argb32, rendering_buffer> pixfmt_argb32;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr32, rendering_buffer> pixfmt_abgr32;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra32, rendering_buffer> pixfmt_bgra32;
-
-    typedef pixfmt_alpha_blend_rgba<blender_srgba32, rendering_buffer> pixfmt_srgba32;
-    typedef pixfmt_alpha_blend_rgba<blender_sargb32, rendering_buffer> pixfmt_sargb32;
-    typedef pixfmt_alpha_blend_rgba<blender_sabgr32, rendering_buffer> pixfmt_sabgr32;
-    typedef pixfmt_alpha_blend_rgba<blender_sbgra32, rendering_buffer> pixfmt_sbgra32;
-
-    typedef pixfmt_alpha_blend_rgba<blender_rgba32_pre, rendering_buffer> pixfmt_rgba32_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_argb32_pre, rendering_buffer> pixfmt_argb32_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr32_pre, rendering_buffer> pixfmt_abgr32_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra32_pre, rendering_buffer> pixfmt_bgra32_pre;
-
-    typedef pixfmt_alpha_blend_rgba<blender_srgba32_pre, rendering_buffer> pixfmt_srgba32_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_sargb32_pre, rendering_buffer> pixfmt_sargb32_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_sabgr32_pre, rendering_buffer> pixfmt_sabgr32_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_sbgra32_pre, rendering_buffer> pixfmt_sbgra32_pre;
-
-    typedef pixfmt_alpha_blend_rgba<blender_rgba32_plain, rendering_buffer> pixfmt_rgba32_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_argb32_plain, rendering_buffer> pixfmt_argb32_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr32_plain, rendering_buffer> pixfmt_abgr32_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra32_plain, rendering_buffer> pixfmt_bgra32_plain;
-
-    typedef pixfmt_alpha_blend_rgba<blender_srgba32_plain, rendering_buffer> pixfmt_srgba32_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_sargb32_plain, rendering_buffer> pixfmt_sargb32_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_sabgr32_plain, rendering_buffer> pixfmt_sabgr32_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_sbgra32_plain, rendering_buffer> pixfmt_sbgra32_plain;
-
-    typedef pixfmt_alpha_blend_rgba<blender_rgba64, rendering_buffer> pixfmt_rgba64;
-    typedef pixfmt_alpha_blend_rgba<blender_argb64, rendering_buffer> pixfmt_argb64;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr64, rendering_buffer> pixfmt_abgr64;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra64, rendering_buffer> pixfmt_bgra64;
-
-    typedef pixfmt_alpha_blend_rgba<blender_rgba64_pre, rendering_buffer> pixfmt_rgba64_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_argb64_pre, rendering_buffer> pixfmt_argb64_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr64_pre, rendering_buffer> pixfmt_abgr64_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra64_pre, rendering_buffer> pixfmt_bgra64_pre;
-
-	typedef pixfmt_alpha_blend_rgba<blender_rgba64_plain, rendering_buffer> pixfmt_rgba64_plain;
-	typedef pixfmt_alpha_blend_rgba<blender_argb64_plain, rendering_buffer> pixfmt_argb64_plain;
-	typedef pixfmt_alpha_blend_rgba<blender_abgr64_plain, rendering_buffer> pixfmt_abgr64_plain;
-	typedef pixfmt_alpha_blend_rgba<blender_bgra64_plain, rendering_buffer> pixfmt_bgra64_plain;
-
-	typedef pixfmt_alpha_blend_rgba<blender_rgba128, rendering_buffer> pixfmt_rgba128;
-    typedef pixfmt_alpha_blend_rgba<blender_argb128, rendering_buffer> pixfmt_argb128;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr128, rendering_buffer> pixfmt_abgr128;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra128, rendering_buffer> pixfmt_bgra128;
-
-    typedef pixfmt_alpha_blend_rgba<blender_rgba128_pre, rendering_buffer> pixfmt_rgba128_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_argb128_pre, rendering_buffer> pixfmt_argb128_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr128_pre, rendering_buffer> pixfmt_abgr128_pre;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra128_pre, rendering_buffer> pixfmt_bgra128_pre;
-
-    typedef pixfmt_alpha_blend_rgba<blender_rgba128_plain, rendering_buffer> pixfmt_rgba128_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_argb128_plain, rendering_buffer> pixfmt_argb128_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_abgr128_plain, rendering_buffer> pixfmt_abgr128_plain;
-    typedef pixfmt_alpha_blend_rgba<blender_bgra128_plain, rendering_buffer> pixfmt_bgra128_plain;
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_pixfmt_transposer.h b/xs/src/agg/agg_pixfmt_transposer.h
deleted file mode 100644
index 64738b6c7..000000000
--- a/xs/src/agg/agg_pixfmt_transposer.h
+++ /dev/null
@@ -1,157 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_PIXFMT_TRANSPOSER_INCLUDED
-#define AGG_PIXFMT_TRANSPOSER_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //=======================================================pixfmt_transposer
-    template<class PixFmt> class pixfmt_transposer
-    {
-    public:
-        typedef PixFmt pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::row_data row_data;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-
-        //--------------------------------------------------------------------
-        pixfmt_transposer() : m_pixf(0) {}
-        explicit pixfmt_transposer(pixfmt_type& pixf) : m_pixf(&pixf) {}
-        void attach(pixfmt_type& pixf) { m_pixf = &pixf; }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE unsigned width()  const { return m_pixf->height();  }
-        AGG_INLINE unsigned height() const { return m_pixf->width(); }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE color_type pixel(int x, int y) const
-        {
-            return m_pixf->pixel(y, x);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_pixel(int x, int y, const color_type& c)
-        {
-            m_pixf->copy_pixel(y, x, c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_pixel(int x, int y, 
-                                    const color_type& c, 
-                                    int8u cover)
-        {
-            m_pixf->blend_pixel(y, x, c, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_hline(int x, int y, 
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            m_pixf->copy_vline(y, x, len, c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_vline(int x, int y,
-                                   unsigned len, 
-                                   const color_type& c)
-        {
-            m_pixf->copy_hline(y, x, len, c);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_hline(int x, int y,
-                                    unsigned len, 
-                                    const color_type& c,
-                                    int8u cover)
-        {
-            m_pixf->blend_vline(y, x, len, c, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_vline(int x, int y,
-                                    unsigned len, 
-                                    const color_type& c,
-                                    int8u cover)
-        {
-            m_pixf->blend_hline(y, x, len, c, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_solid_hspan(int x, int y,
-                                          unsigned len, 
-                                          const color_type& c,
-                                          const int8u* covers)
-        {
-            m_pixf->blend_solid_vspan(y, x, len, c, covers);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_solid_vspan(int x, int y,
-                                          unsigned len, 
-                                          const color_type& c,
-                                          const int8u* covers)
-        {
-            m_pixf->blend_solid_hspan(y, x, len, c, covers);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_color_hspan(int x, int y,
-                                         unsigned len, 
-                                         const color_type* colors)
-        {
-            m_pixf->copy_color_vspan(y, x, len, colors);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void copy_color_vspan(int x, int y,
-                                         unsigned len, 
-                                         const color_type* colors)
-        {
-            m_pixf->copy_color_hspan(y, x, len, colors);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_color_hspan(int x, int y,
-                                          unsigned len, 
-                                          const color_type* colors,
-                                          const int8u* covers,
-                                          int8u cover)
-        {
-            m_pixf->blend_color_vspan(y, x, len, colors, covers, cover);
-        }
-
-        //--------------------------------------------------------------------
-        AGG_INLINE void blend_color_vspan(int x, int y,
-                               unsigned len, 
-                               const color_type* colors,
-                               const int8u* covers,
-                               int8u cover)
-        {
-            m_pixf->blend_color_hspan(y, x, len, colors, covers, cover);
-        }
-
-    private:
-        pixfmt_type* m_pixf;
-    };
-}
-
-#endif
-
-
diff --git a/xs/src/agg/agg_rasterizer_compound_aa.h b/xs/src/agg/agg_rasterizer_compound_aa.h
deleted file mode 100644
index 72d811be0..000000000
--- a/xs/src/agg/agg_rasterizer_compound_aa.h
+++ /dev/null
@@ -1,665 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.3
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-//
-// The author gratefully acknowleges the support of David Turner, 
-// Robert Wilhelm, and Werner Lemberg - the authors of the FreeType 
-// libray - in producing this work. See http://www.freetype.org for details.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for 32-bit screen coordinates has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-#ifndef AGG_RASTERIZER_COMPOUND_AA_INCLUDED
-#define AGG_RASTERIZER_COMPOUND_AA_INCLUDED
-
-#include <limits>
-#include "agg_rasterizer_cells_aa.h"
-#include "agg_rasterizer_sl_clip.h"
-
-namespace agg
-{
-
-    //-----------------------------------------------------------cell_style_aa
-    // A pixel cell. There're no constructors defined and it was done 
-    // intentionally in order to avoid extra overhead when allocating an 
-    // array of cells.
-    struct cell_style_aa
-    {
-        int   x;
-        int   y;
-        int   cover;
-        int   area;
-        int16 left, right;
-
-        void initial()
-        {
-            x     = std::numeric_limits<int>::max();
-            y     = std::numeric_limits<int>::max();
-            cover = 0;
-            area  = 0;
-            left  = -1;
-            right = -1;
-        }
-
-        void style(const cell_style_aa& c)
-        {
-            left  = c.left;
-            right = c.right;
-        }
-
-        int not_equal(int ex, int ey, const cell_style_aa& c) const
-        {
-            return ((unsigned)ex - (unsigned)x) | ((unsigned)ey - (unsigned)y) | 
-                   ((unsigned)left - (unsigned)c.left) | ((unsigned)right - (unsigned)c.right);
-        }
-    };
-
-
-    //===========================================================layer_order_e
-    enum layer_order_e
-    {
-        layer_unsorted, //------layer_unsorted
-        layer_direct,   //------layer_direct
-        layer_inverse   //------layer_inverse
-    };
-
-
-    //==================================================rasterizer_compound_aa
-    template<class Clip=rasterizer_sl_clip_int> class rasterizer_compound_aa
-    {
-        struct style_info 
-        { 
-            unsigned start_cell;
-            unsigned num_cells;
-            int      last_x;
-        };
-
-        struct cell_info
-        {
-            int x, area, cover; 
-        };
-
-    public:
-        typedef Clip                      clip_type;
-        typedef typename Clip::conv_type  conv_type;
-        typedef typename Clip::coord_type coord_type;
-
-        enum aa_scale_e
-        {
-            aa_shift  = 8,
-            aa_scale  = 1 << aa_shift,
-            aa_mask   = aa_scale - 1,
-            aa_scale2 = aa_scale * 2,
-            aa_mask2  = aa_scale2 - 1
-        };
-
-        //--------------------------------------------------------------------
-        rasterizer_compound_aa() : 
-            m_outline(),
-            m_clipper(),
-            m_filling_rule(fill_non_zero),
-            m_layer_order(layer_direct),
-            m_styles(),  // Active Styles
-            m_ast(),     // Active Style Table (unique values)
-            m_asm(),     // Active Style Mask 
-            m_cells(),
-            m_cover_buf(),
-            m_min_style(std::numeric_limits<int>::max()),
-            m_max_style(std::numeric_limits<int>::min()),
-            m_start_x(0),
-            m_start_y(0),
-            m_scan_y(std::numeric_limits<int>::max()),
-            m_sl_start(0),
-            m_sl_len(0)
-        {}
-
-        //--------------------------------------------------------------------
-        void reset(); 
-        void reset_clipping();
-        void clip_box(double x1, double y1, double x2, double y2);
-        void filling_rule(filling_rule_e filling_rule);
-        void layer_order(layer_order_e order);
-
-        //--------------------------------------------------------------------
-        void styles(int left, int right);
-        void move_to(int x, int y);
-        void line_to(int x, int y);
-        void move_to_d(double x, double y);
-        void line_to_d(double x, double y);
-        void add_vertex(double x, double y, unsigned cmd);
-
-        void edge(int x1, int y1, int x2, int y2);
-        void edge_d(double x1, double y1, double x2, double y2);
-
-        //-------------------------------------------------------------------
-        template<class VertexSource>
-        void add_path(VertexSource& vs, unsigned path_id=0)
-        {
-            double x;
-            double y;
-
-            unsigned cmd;
-            vs.rewind(path_id);
-            if(m_outline.sorted()) reset();
-            while(!is_stop(cmd = vs.vertex(&x, &y)))
-            {
-                add_vertex(x, y, cmd);
-            }
-        }
-
-        
-        //--------------------------------------------------------------------
-        int min_x()     const { return m_outline.min_x(); }
-        int min_y()     const { return m_outline.min_y(); }
-        int max_x()     const { return m_outline.max_x(); }
-        int max_y()     const { return m_outline.max_y(); }
-        int min_style() const { return m_min_style; }
-        int max_style() const { return m_max_style; }
-
-        //--------------------------------------------------------------------
-        void sort();
-        bool rewind_scanlines();
-        unsigned sweep_styles();
-        int      scanline_start()  const { return m_sl_start; }
-        unsigned scanline_length() const { return m_sl_len;   }
-        unsigned style(unsigned style_idx) const;
-
-        cover_type* allocate_cover_buffer(unsigned len);
-
-        //--------------------------------------------------------------------
-        bool navigate_scanline(int y); 
-        bool hit_test(int tx, int ty);
-
-        //--------------------------------------------------------------------
-        AGG_INLINE unsigned calculate_alpha(int area) const
-        {
-            int cover = area >> (poly_subpixel_shift*2 + 1 - aa_shift);
-            if(cover < 0) cover = -cover;
-            if(m_filling_rule == fill_even_odd)
-            {
-                cover &= aa_mask2;
-                if(cover > aa_scale)
-                {
-                    cover = aa_scale2 - cover;
-                }
-            }
-            if(cover > aa_mask) cover = aa_mask;
-            return cover;
-        }
-
-        //--------------------------------------------------------------------
-        // Sweeps one scanline with one style index. The style ID can be 
-        // determined by calling style(). 
-        template<class Scanline> bool sweep_scanline(Scanline& sl, int style_idx)
-        {
-            int scan_y = m_scan_y - 1;
-            if(scan_y > m_outline.max_y()) return false;
-
-            sl.reset_spans();
-
-            if(style_idx < 0) 
-            {
-                style_idx = 0;
-            }
-            else 
-            {
-                style_idx++;
-            }
-
-            const style_info& st = m_styles[m_ast[style_idx]];
-
-            unsigned num_cells = st.num_cells;
-            cell_info* cell = &m_cells[st.start_cell];
-
-            int cover = 0;
-            while(num_cells--)
-            {
-                unsigned alpha;
-                int x = cell->x;
-                int area = cell->area;
-
-                cover += cell->cover;
-
-                ++cell;
-
-                if(area)
-                {
-                    alpha = calculate_alpha((cover << (poly_subpixel_shift + 1)) - area);
-                    sl.add_cell(x, alpha);
-                    x++;
-                }
-
-                if(num_cells && cell->x > x)
-                {
-                    alpha = calculate_alpha(cover << (poly_subpixel_shift + 1));
-                    if(alpha)
-                    {
-                        sl.add_span(x, cell->x - x, alpha);
-                    }
-                }
-            }
-
-            if(sl.num_spans() == 0) return false;
-            sl.finalize(scan_y);
-            return true;
-        }
-
-    private:
-        void add_style(int style_id);
-
-        //--------------------------------------------------------------------
-        // Disable copying
-        rasterizer_compound_aa(const rasterizer_compound_aa<Clip>&);
-        const rasterizer_compound_aa<Clip>& 
-        operator = (const rasterizer_compound_aa<Clip>&);
-
-    private:
-        rasterizer_cells_aa<cell_style_aa> m_outline;
-        clip_type              m_clipper;
-        filling_rule_e         m_filling_rule;
-        layer_order_e          m_layer_order;
-        pod_vector<style_info> m_styles;  // Active Styles
-        pod_vector<unsigned>   m_ast;     // Active Style Table (unique values)
-        pod_vector<int8u>      m_asm;     // Active Style Mask 
-        pod_vector<cell_info>  m_cells;
-        pod_vector<cover_type> m_cover_buf;
-
-        int        m_min_style;
-        int        m_max_style;
-        coord_type m_start_x;
-        coord_type m_start_y;
-        int        m_scan_y;
-        int        m_sl_start;
-        unsigned   m_sl_len;
-    };
-
-
-
-
-
-
-
-
-
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::reset() 
-    { 
-        m_outline.reset(); 
-        m_min_style = std::numeric_limits<int>::max();
-        m_max_style = std::numeric_limits<int>::min();
-        m_scan_y    = std::numeric_limits<int>::max();
-        m_sl_start  =  0;
-        m_sl_len    = 0;
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::filling_rule(filling_rule_e filling_rule) 
-    { 
-        m_filling_rule = filling_rule; 
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::layer_order(layer_order_e order)
-    {
-        m_layer_order = order;
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::clip_box(double x1, double y1, 
-                                                double x2, double y2)
-    {
-        reset();
-        m_clipper.clip_box(conv_type::upscale(x1), conv_type::upscale(y1), 
-                           conv_type::upscale(x2), conv_type::upscale(y2));
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::reset_clipping()
-    {
-        reset();
-        m_clipper.reset_clipping();
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::styles(int left, int right)
-    {
-        cell_style_aa cell;
-        cell.initial();
-        cell.left = (int16)left;
-        cell.right = (int16)right;
-        m_outline.style(cell);
-        if(left  >= 0 && left  < m_min_style) m_min_style = left;
-        if(left  >= 0 && left  > m_max_style) m_max_style = left;
-        if(right >= 0 && right < m_min_style) m_min_style = right;
-        if(right >= 0 && right > m_max_style) m_max_style = right;
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::move_to(int x, int y)
-    {
-        if(m_outline.sorted()) reset();
-        m_clipper.move_to(m_start_x = conv_type::downscale(x), 
-                          m_start_y = conv_type::downscale(y));
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::line_to(int x, int y)
-    {
-        m_clipper.line_to(m_outline, 
-                          conv_type::downscale(x), 
-                          conv_type::downscale(y));
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::move_to_d(double x, double y) 
-    { 
-        if(m_outline.sorted()) reset();
-        m_clipper.move_to(m_start_x = conv_type::upscale(x), 
-                          m_start_y = conv_type::upscale(y)); 
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::line_to_d(double x, double y) 
-    { 
-        m_clipper.line_to(m_outline, 
-                          conv_type::upscale(x), 
-                          conv_type::upscale(y)); 
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::add_vertex(double x, double y, unsigned cmd)
-    {
-        if(is_move_to(cmd)) 
-        {
-            move_to_d(x, y);
-        }
-        else 
-        if(is_vertex(cmd))
-        {
-            line_to_d(x, y);
-        }
-        else
-        if(is_close(cmd))
-        {
-            m_clipper.line_to(m_outline, m_start_x, m_start_y);
-        }
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::edge(int x1, int y1, int x2, int y2)
-    {
-        if(m_outline.sorted()) reset();
-        m_clipper.move_to(conv_type::downscale(x1), conv_type::downscale(y1));
-        m_clipper.line_to(m_outline, 
-                          conv_type::downscale(x2), 
-                          conv_type::downscale(y2));
-    }
-    
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    void rasterizer_compound_aa<Clip>::edge_d(double x1, double y1, 
-                                              double x2, double y2)
-    {
-        if(m_outline.sorted()) reset();
-        m_clipper.move_to(conv_type::upscale(x1), conv_type::upscale(y1)); 
-        m_clipper.line_to(m_outline, 
-                          conv_type::upscale(x2), 
-                          conv_type::upscale(y2)); 
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    AGG_INLINE void rasterizer_compound_aa<Clip>::sort()
-    {
-        m_outline.sort_cells();
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    AGG_INLINE bool rasterizer_compound_aa<Clip>::rewind_scanlines()
-    {
-        m_outline.sort_cells();
-        if(m_outline.total_cells() == 0) 
-        {
-            return false;
-        }
-        if(m_max_style < m_min_style)
-        {
-            return false;
-        }
-        m_scan_y = m_outline.min_y();
-        m_styles.allocate(m_max_style - m_min_style + 2, 128);
-        return true;
-    }
-
-    //------------------------------------------------------------------------
-    template<class Clip> 
-    AGG_INLINE void rasterizer_compound_aa<Clip>::add_style(int style_id)
-    {
-        if(style_id < 0) style_id  = 0;
-        else             style_id -= m_min_style - 1;
-
-        unsigned nbyte = style_id >> 3;
-        unsigned mask = 1 << (style_id & 7);
-
-        style_info* style = &m_styles[style_id];
-        if((m_asm[nbyte] & mask) == 0)
-        {
-            m_ast.add(style_id);
-            m_asm[nbyte] |= mask;
-            style->start_cell = 0;
-            style->num_cells = 0;
-            style->last_x = std::numeric_limits<int>::min();
-        }
-        ++style->start_cell;
-    }
-
-    //------------------------------------------------------------------------
-    // Returns the number of styles
-    template<class Clip> 
-    unsigned rasterizer_compound_aa<Clip>::sweep_styles()
-    {
-        for(;;)
-        {
-            if(m_scan_y > m_outline.max_y()) return 0;
-            unsigned num_cells = m_outline.scanline_num_cells(m_scan_y);
-            const cell_style_aa* const* cells = m_outline.scanline_cells(m_scan_y);
-            unsigned num_styles = m_max_style - m_min_style + 2;
-            const cell_style_aa* curr_cell;
-            unsigned style_id;
-            style_info* style;
-            cell_info* cell;
-
-            m_cells.allocate(num_cells * 2, 256); // Each cell can have two styles
-            m_ast.capacity(num_styles, 64);
-            m_asm.allocate((num_styles + 7) >> 3, 8);
-            m_asm.zero();
-
-            if(num_cells)
-            {
-                // Pre-add zero (for no-fill style, that is, -1).
-                // We need that to ensure that the "-1 style" would go first.
-                m_asm[0] |= 1; 
-                m_ast.add(0);
-                style = &m_styles[0];
-                style->start_cell = 0;
-                style->num_cells = 0;
-                style->last_x = std::numeric_limits<int>::min();
-
-                m_sl_start = cells[0]->x;
-                m_sl_len   = cells[num_cells-1]->x - m_sl_start + 1;
-                while(num_cells--)
-                {
-                    curr_cell = *cells++;
-                    add_style(curr_cell->left);
-                    add_style(curr_cell->right);
-                }
-
-                // Convert the Y-histogram into the array of starting indexes
-                unsigned i;
-                unsigned start_cell = 0;
-                for(i = 0; i < m_ast.size(); i++)
-                {
-                    style_info& st = m_styles[m_ast[i]];
-                    unsigned v = st.start_cell;
-                    st.start_cell = start_cell;
-                    start_cell += v;
-                }
-
-                cells = m_outline.scanline_cells(m_scan_y);
-                num_cells = m_outline.scanline_num_cells(m_scan_y);
-
-                while(num_cells--)
-                {
-                    curr_cell = *cells++;
-                    style_id = (curr_cell->left < 0) ? 0 : 
-                                curr_cell->left - m_min_style + 1;
-
-                    style = &m_styles[style_id];
-                    if(curr_cell->x == style->last_x)
-                    {
-                        cell = &m_cells[style->start_cell + style->num_cells - 1];
-                        cell->area  += curr_cell->area;
-                        cell->cover += curr_cell->cover;
-                    }
-                    else
-                    {
-                        cell = &m_cells[style->start_cell + style->num_cells];
-                        cell->x       = curr_cell->x;
-                        cell->area    = curr_cell->area;
-                        cell->cover   = curr_cell->cover;
-                        style->last_x = curr_cell->x;
-                        style->num_cells++;
-                    }
-
-                    style_id = (curr_cell->right < 0) ? 0 : 
-                                curr_cell->right - m_min_style + 1;
-
-                    style = &m_styles[style_id];
-                    if(curr_cell->x == style->last_x)
-                    {
-                        cell = &m_cells[style->start_cell + style->num_cells - 1];
-                        cell->area  -= curr_cell->area;
-                        cell->cover -= curr_cell->cover;
-                    }
-                    else
-                    {
-                        cell = &m_cells[style->start_cell + style->num_cells];
-                        cell->x       =  curr_cell->x;
-                        cell->area    = -curr_cell->area;
-                        cell->cover   = -curr_cell->cover;
-                        style->last_x =  curr_cell->x;
-                        style->num_cells++;
-                    }
-                }
-            }
-            if(m_ast.size() > 1) break;
-            ++m_scan_y;
-        }
-        ++m_scan_y;
-
-        if(m_layer_order != layer_unsorted)
-        {
-            range_adaptor<pod_vector<unsigned> > ra(m_ast, 1, m_ast.size() - 1);
-            if(m_layer_order == layer_direct) quick_sort(ra, unsigned_greater);
-            else                              quick_sort(ra, unsigned_less);
-        }
-
-        return m_ast.size() - 1;
-    }
-
-    //------------------------------------------------------------------------
-    // Returns style ID depending of the existing style index
-    template<class Clip> 
-    AGG_INLINE 
-    unsigned rasterizer_compound_aa<Clip>::style(unsigned style_idx) const
-    {
-        return m_ast[style_idx + 1] + m_min_style - 1;
-    }
-
-    //------------------------------------------------------------------------ 
-    template<class Clip> 
-    AGG_INLINE bool rasterizer_compound_aa<Clip>::navigate_scanline(int y)
-    {
-        m_outline.sort_cells();
-        if(m_outline.total_cells() == 0) 
-        {
-            return false;
-        }
-        if(m_max_style < m_min_style)
-        {
-            return false;
-        }
-        if(y < m_outline.min_y() || y > m_outline.max_y()) 
-        {
-            return false;
-        }
-        m_scan_y = y;
-        m_styles.allocate(m_max_style - m_min_style + 2, 128);
-        return true;
-    }
-    
-    //------------------------------------------------------------------------ 
-    template<class Clip> 
-    bool rasterizer_compound_aa<Clip>::hit_test(int tx, int ty)
-    {
-        if(!navigate_scanline(ty)) 
-        {
-            return false;
-        }
-
-        unsigned num_styles = sweep_styles(); 
-        if(num_styles <= 0)
-        {
-            return false;
-        }
-
-        scanline_hit_test sl(tx);
-        sweep_scanline(sl, -1);
-        return sl.hit();
-    }
-
-    //------------------------------------------------------------------------ 
-    template<class Clip> 
-    cover_type* rasterizer_compound_aa<Clip>::allocate_cover_buffer(unsigned len)
-    {
-        m_cover_buf.allocate(len, 256);
-        return &m_cover_buf[0];
-    }
-
-}
-
-
-
-#endif
-
diff --git a/xs/src/agg/agg_rasterizer_outline.h b/xs/src/agg/agg_rasterizer_outline.h
deleted file mode 100644
index 65203e34c..000000000
--- a/xs/src/agg/agg_rasterizer_outline.h
+++ /dev/null
@@ -1,147 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_RASTERIZER_OUTLINE_INCLUDED
-#define AGG_RASTERIZER_OUTLINE_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //======================================================rasterizer_outline
-    template<class Renderer> class rasterizer_outline
-    {
-    public:
-        explicit rasterizer_outline(Renderer& ren) : 
-            m_ren(&ren), 
-            m_start_x(0), 
-            m_start_y(0), 
-            m_vertices(0)
-        {}
-        void attach(Renderer& ren) { m_ren = &ren; }
-
-
-        //--------------------------------------------------------------------
-        void move_to(int x, int y)
-        {
-            m_vertices = 1;
-            m_ren->move_to(m_start_x = x, m_start_y = y);
-        }
-
-        //--------------------------------------------------------------------
-        void line_to(int x, int y)
-        {
-            ++m_vertices;
-            m_ren->line_to(x, y);
-        }
-
-        //--------------------------------------------------------------------
-        void move_to_d(double x, double y)
-        {
-            move_to(m_ren->coord(x), m_ren->coord(y));
-        }
-
-        //--------------------------------------------------------------------
-        void line_to_d(double x, double y)
-        {
-            line_to(m_ren->coord(x), m_ren->coord(y));
-        }
-
-        //--------------------------------------------------------------------
-        void close()
-        {
-            if(m_vertices > 2)
-            {
-                line_to(m_start_x, m_start_y);
-            }
-            m_vertices = 0;
-        }
-
-        //--------------------------------------------------------------------
-        void add_vertex(double x, double y, unsigned cmd)
-        {
-            if(is_move_to(cmd)) 
-            {
-                move_to_d(x, y);
-            }
-            else 
-            {
-                if(is_end_poly(cmd))
-                {
-                    if(is_closed(cmd)) close();
-                }
-                else
-                {
-                    line_to_d(x, y);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        template<class VertexSource>
-        void add_path(VertexSource& vs, unsigned path_id=0)
-        {
-            double x;
-            double y;
-
-            unsigned cmd;
-            vs.rewind(path_id);
-            while(!is_stop(cmd = vs.vertex(&x, &y)))
-            {
-                add_vertex(x, y, cmd);
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        template<class VertexSource, class ColorStorage, class PathId>
-        void render_all_paths(VertexSource& vs, 
-                              const ColorStorage& colors, 
-                              const PathId& path_id,
-                              unsigned num_paths)
-        {
-            for(unsigned i = 0; i < num_paths; i++)
-            {
-                m_ren->line_color(colors[i]);
-                add_path(vs, path_id[i]);
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        template<class Ctrl> void render_ctrl(Ctrl& c)
-        {
-            unsigned i;
-            for(i = 0; i < c.num_paths(); i++)
-            {
-                m_ren->line_color(c.color(i));
-                add_path(c, i);
-            }
-        }
-
-
-    private:
-        Renderer* m_ren;
-        int       m_start_x;
-        int       m_start_y;
-        unsigned  m_vertices;
-    };
-
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_rasterizer_outline_aa.h b/xs/src/agg/agg_rasterizer_outline_aa.h
deleted file mode 100644
index a06bd1e84..000000000
--- a/xs/src/agg/agg_rasterizer_outline_aa.h
+++ /dev/null
@@ -1,599 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_RASTERIZER_OUTLINE_AA_INCLUDED
-#define AGG_RASTERIZER_OUTLINE_AA_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_line_aa_basics.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-
-    //-------------------------------------------------------------------------
-    inline bool cmp_dist_start(int d) { return d > 0;  }
-    inline bool cmp_dist_end(int d)   { return d <= 0; }
-
-
-
-    //-----------------------------------------------------------line_aa_vertex
-    // Vertex (x, y) with the distance to the next one. The last vertex has 
-    // the distance between the last and the first points
-    struct line_aa_vertex
-    {
-        int x;
-        int y;
-        int len;
-
-        line_aa_vertex() {}
-        line_aa_vertex(int x_, int y_) :
-            x(x_),
-            y(y_),
-            len(0)
-        {
-        }
-
-        bool operator () (const line_aa_vertex& val)
-        {
-            double dx = val.x - x;
-            double dy = val.y - y;
-            return (len = uround(sqrt(dx * dx + dy * dy))) > 
-                   (line_subpixel_scale + line_subpixel_scale / 2);
-        }
-    };
-
-
-    //----------------------------------------------------------outline_aa_join_e
-    enum outline_aa_join_e
-    {
-        outline_no_join,             //-----outline_no_join
-        outline_miter_join,          //-----outline_miter_join
-        outline_round_join,          //-----outline_round_join
-        outline_miter_accurate_join  //-----outline_accurate_join
-    };
-
-    //=======================================================rasterizer_outline_aa
-    template<class Renderer, class Coord=line_coord> class rasterizer_outline_aa
-    {
-    private:
-        //------------------------------------------------------------------------
-        struct draw_vars
-        {
-            unsigned idx;
-            int x1, y1, x2, y2;
-            line_parameters curr, next;
-            int lcurr, lnext;
-            int xb1, yb1, xb2, yb2;
-            unsigned flags;
-        };
-
-        void draw(draw_vars& dv, unsigned start, unsigned end);
-
-    public:
-        typedef line_aa_vertex                  vertex_type;
-        typedef vertex_sequence<vertex_type, 6> vertex_storage_type;
-
-        explicit rasterizer_outline_aa(Renderer& ren) : 
-            m_ren(&ren), 
-            m_line_join(ren.accurate_join_only() ? 
-                            outline_miter_accurate_join : 
-                            outline_round_join),
-            m_round_cap(false),
-            m_start_x(0),
-            m_start_y(0)
-        {}
-        void attach(Renderer& ren) { m_ren = &ren; }
-
-        //------------------------------------------------------------------------
-        void line_join(outline_aa_join_e join) 
-        { 
-            m_line_join = m_ren->accurate_join_only() ? 
-                outline_miter_accurate_join : 
-                join; 
-        }
-        bool line_join() const { return m_line_join; }
-
-        //------------------------------------------------------------------------
-        void round_cap(bool v) { m_round_cap = v; }
-        bool round_cap() const { return m_round_cap; }
-
-        //------------------------------------------------------------------------
-        void move_to(int x, int y)
-        {
-            m_src_vertices.modify_last(vertex_type(m_start_x = x, m_start_y = y));
-        }
-
-        //------------------------------------------------------------------------
-        void line_to(int x, int y)
-        {
-            m_src_vertices.add(vertex_type(x, y));
-        }
-
-        //------------------------------------------------------------------------
-        void move_to_d(double x, double y)
-        {
-            move_to(Coord::conv(x), Coord::conv(y));
-        }
-
-        //------------------------------------------------------------------------
-        void line_to_d(double x, double y)
-        {
-            line_to(Coord::conv(x), Coord::conv(y));
-        }
-
-        //------------------------------------------------------------------------
-        void render(bool close_polygon);
-
-        //------------------------------------------------------------------------
-        void add_vertex(double x, double y, unsigned cmd)
-        {
-            if(is_move_to(cmd)) 
-            {
-                render(false);
-                move_to_d(x, y);
-            }
-            else 
-            {
-                if(is_end_poly(cmd))
-                {
-                    render(is_closed(cmd));
-                    if(is_closed(cmd)) 
-                    {
-                        move_to(m_start_x, m_start_y);
-                    }
-                }
-                else
-                {
-                    line_to_d(x, y);
-                }
-            }
-        }
-
-        //------------------------------------------------------------------------
-        template<class VertexSource>
-        void add_path(VertexSource& vs, unsigned path_id=0)
-        {
-            double x;
-            double y;
-
-            unsigned cmd;
-            vs.rewind(path_id);
-            while(!is_stop(cmd = vs.vertex(&x, &y)))
-            {
-                add_vertex(x, y, cmd);
-            }
-            render(false);
-        }
-
-
-        //------------------------------------------------------------------------
-        template<class VertexSource, class ColorStorage, class PathId>
-        void render_all_paths(VertexSource& vs, 
-                              const ColorStorage& colors, 
-                              const PathId& path_id,
-                              unsigned num_paths)
-        {
-            for(unsigned i = 0; i < num_paths; i++)
-            {
-                m_ren->color(colors[i]);
-                add_path(vs, path_id[i]);
-            }
-        }
-
-
-        //------------------------------------------------------------------------
-        template<class Ctrl> void render_ctrl(Ctrl& c)
-        {
-            unsigned i;
-            for(i = 0; i < c.num_paths(); i++)
-            {
-                m_ren->color(c.color(i));
-                add_path(c, i);
-            }
-        }
-
-    private:
-        rasterizer_outline_aa(const rasterizer_outline_aa<Renderer, Coord>&);
-        const rasterizer_outline_aa<Renderer, Coord>& operator = 
-            (const rasterizer_outline_aa<Renderer, Coord>&);
-
-        Renderer*           m_ren;
-        vertex_storage_type m_src_vertices;
-        outline_aa_join_e   m_line_join;
-        bool                m_round_cap;
-        int                 m_start_x;
-        int                 m_start_y;
-    };
-
-
-
-
-
-
-
-
-    //----------------------------------------------------------------------------
-    template<class Renderer, class Coord> 
-    void rasterizer_outline_aa<Renderer, Coord>::draw(draw_vars& dv, 
-                                                      unsigned start, 
-                                                      unsigned end)
-    {
-        unsigned i;
-        const vertex_storage_type::value_type* v;
-
-        for(i = start; i < end; i++)
-        {
-            if(m_line_join == outline_round_join)
-            {
-                dv.xb1 = dv.curr.x1 + (dv.curr.y2 - dv.curr.y1); 
-                dv.yb1 = dv.curr.y1 - (dv.curr.x2 - dv.curr.x1); 
-                dv.xb2 = dv.curr.x2 + (dv.curr.y2 - dv.curr.y1); 
-                dv.yb2 = dv.curr.y2 - (dv.curr.x2 - dv.curr.x1);
-            }
-
-            switch(dv.flags)
-            {
-            case 0: m_ren->line3(dv.curr, dv.xb1, dv.yb1, dv.xb2, dv.yb2); break;
-            case 1: m_ren->line2(dv.curr, dv.xb2, dv.yb2); break;
-            case 2: m_ren->line1(dv.curr, dv.xb1, dv.yb1); break;
-            case 3: m_ren->line0(dv.curr); break;
-            }
-
-            if(m_line_join == outline_round_join && (dv.flags & 2) == 0)
-            {
-                m_ren->pie(dv.curr.x2, dv.curr.y2, 
-                           dv.curr.x2 + (dv.curr.y2 - dv.curr.y1),
-                           dv.curr.y2 - (dv.curr.x2 - dv.curr.x1),
-                           dv.curr.x2 + (dv.next.y2 - dv.next.y1),
-                           dv.curr.y2 - (dv.next.x2 - dv.next.x1));
-            }
-
-            dv.x1 = dv.x2;
-            dv.y1 = dv.y2;
-            dv.lcurr = dv.lnext;
-            dv.lnext = m_src_vertices[dv.idx].len;
-
-            ++dv.idx;
-            if(dv.idx >= m_src_vertices.size()) dv.idx = 0; 
-
-            v = &m_src_vertices[dv.idx];
-            dv.x2 = v->x;
-            dv.y2 = v->y;
-
-            dv.curr = dv.next;
-            dv.next = line_parameters(dv.x1, dv.y1, dv.x2, dv.y2, dv.lnext);
-            dv.xb1 = dv.xb2;
-            dv.yb1 = dv.yb2;
-
-            switch(m_line_join)
-            {
-            case outline_no_join:
-                dv.flags = 3;
-                break;
-
-            case outline_miter_join:
-                dv.flags >>= 1;
-                dv.flags |= ((dv.curr.diagonal_quadrant() == 
-                              dv.next.diagonal_quadrant()) << 1);
-                if((dv.flags & 2) == 0)
-                {
-                    bisectrix(dv.curr, dv.next, &dv.xb2, &dv.yb2);
-                }
-                break;
-
-            case outline_round_join:
-                dv.flags >>= 1;
-                dv.flags |= ((dv.curr.diagonal_quadrant() == 
-                              dv.next.diagonal_quadrant()) << 1);
-                break;
-
-            case outline_miter_accurate_join:
-                dv.flags = 0;
-                bisectrix(dv.curr, dv.next, &dv.xb2, &dv.yb2);
-                break;
-            }
-        }
-    }
-
-
-
-
-    //----------------------------------------------------------------------------
-    template<class Renderer, class Coord> 
-    void rasterizer_outline_aa<Renderer, Coord>::render(bool close_polygon)
-    {
-        m_src_vertices.close(close_polygon);
-        draw_vars dv;
-        const vertex_storage_type::value_type* v;
-        int x1;
-        int y1;
-        int x2;
-        int y2;
-        int lprev;
-
-        if(close_polygon)
-        {
-            if(m_src_vertices.size() >= 3)
-            {
-                dv.idx = 2;
-
-                v     = &m_src_vertices[m_src_vertices.size() - 1];
-                x1    = v->x;
-                y1    = v->y;
-                lprev = v->len;
-
-                v  = &m_src_vertices[0];
-                x2 = v->x;
-                y2 = v->y;
-                dv.lcurr = v->len;
-                line_parameters prev(x1, y1, x2, y2, lprev);
-
-                v = &m_src_vertices[1];
-                dv.x1    = v->x;
-                dv.y1    = v->y;
-                dv.lnext = v->len;
-                dv.curr = line_parameters(x2, y2, dv.x1, dv.y1, dv.lcurr);
-
-                v = &m_src_vertices[dv.idx];
-                dv.x2 = v->x;
-                dv.y2 = v->y;
-                dv.next = line_parameters(dv.x1, dv.y1, dv.x2, dv.y2, dv.lnext);
-
-                dv.xb1 = 0;
-                dv.yb1 = 0;
-                dv.xb2 = 0;
-                dv.yb2 = 0;
-
-                switch(m_line_join)
-                {
-                case outline_no_join:
-                    dv.flags = 3;
-                    break;
-
-                case outline_miter_join:
-                case outline_round_join:
-                    dv.flags = 
-                            (prev.diagonal_quadrant() == dv.curr.diagonal_quadrant()) |
-                        ((dv.curr.diagonal_quadrant() == dv.next.diagonal_quadrant()) << 1);
-                    break;
-
-                case outline_miter_accurate_join:
-                    dv.flags = 0;
-                    break;
-                }
-
-                if((dv.flags & 1) == 0 && m_line_join != outline_round_join)
-                {
-                    bisectrix(prev, dv.curr, &dv.xb1, &dv.yb1);
-                }
-
-                if((dv.flags & 2) == 0 && m_line_join != outline_round_join)
-                {
-                    bisectrix(dv.curr, dv.next, &dv.xb2, &dv.yb2);
-                }
-                draw(dv, 0, m_src_vertices.size());
-            }
-        }
-        else
-        {
-            switch(m_src_vertices.size())
-            {
-                case 0:
-                case 1:
-                    break;
-
-                case 2:
-                {
-                    v     = &m_src_vertices[0];
-                    x1    = v->x;
-                    y1    = v->y;
-                    lprev = v->len;
-                    v     = &m_src_vertices[1];
-                    x2    = v->x;
-                    y2    = v->y;
-                    line_parameters lp(x1, y1, x2, y2, lprev);
-                    if(m_round_cap) 
-                    {
-                        m_ren->semidot(cmp_dist_start, x1, y1, x1 + (y2 - y1), y1 - (x2 - x1));
-                    }
-                    m_ren->line3(lp, 
-                                 x1 + (y2 - y1), 
-                                 y1 - (x2 - x1),
-                                 x2 + (y2 - y1), 
-                                 y2 - (x2 - x1));
-                    if(m_round_cap) 
-                    {
-                        m_ren->semidot(cmp_dist_end, x2, y2, x2 + (y2 - y1), y2 - (x2 - x1));
-                    }
-                }
-                break;
-
-                case 3:
-                {
-                    int x3, y3;
-                    int lnext;
-                    v     = &m_src_vertices[0];
-                    x1    = v->x;
-                    y1    = v->y;
-                    lprev = v->len;
-                    v     = &m_src_vertices[1];
-                    x2    = v->x;
-                    y2    = v->y;
-                    lnext = v->len;
-                    v     = &m_src_vertices[2];
-                    x3    = v->x;
-                    y3    = v->y;
-                    line_parameters lp1(x1, y1, x2, y2, lprev);
-                    line_parameters lp2(x2, y2, x3, y3, lnext);
-
-                    if(m_round_cap) 
-                    {
-                        m_ren->semidot(cmp_dist_start, x1, y1, x1 + (y2 - y1), y1 - (x2 - x1));
-                    }
-
-                    if(m_line_join == outline_round_join)
-                    {
-                        m_ren->line3(lp1, x1 + (y2 - y1), y1 - (x2 - x1), 
-                                          x2 + (y2 - y1), y2 - (x2 - x1));
-
-                        m_ren->pie(x2, y2, x2 + (y2 - y1), y2 - (x2 - x1),
-                                           x2 + (y3 - y2), y2 - (x3 - x2));
-
-                        m_ren->line3(lp2, x2 + (y3 - y2), y2 - (x3 - x2),
-                                          x3 + (y3 - y2), y3 - (x3 - x2));
-                    }
-                    else
-                    {
-                        bisectrix(lp1, lp2, &dv.xb1, &dv.yb1);
-                        m_ren->line3(lp1, x1 + (y2 - y1), y1 - (x2 - x1),
-                                          dv.xb1,         dv.yb1);
-
-                        m_ren->line3(lp2, dv.xb1,         dv.yb1,
-                                          x3 + (y3 - y2), y3 - (x3 - x2));
-                    }
-                    if(m_round_cap) 
-                    {
-                        m_ren->semidot(cmp_dist_end, x3, y3, x3 + (y3 - y2), y3 - (x3 - x2));
-                    }
-                }
-                break;
-
-                default:
-                {
-                    dv.idx = 3;
-
-                    v     = &m_src_vertices[0];
-                    x1    = v->x;
-                    y1    = v->y;
-                    lprev = v->len;
-
-                    v  = &m_src_vertices[1];
-                    x2 = v->x;
-                    y2 = v->y;
-                    dv.lcurr = v->len;
-                    line_parameters prev(x1, y1, x2, y2, lprev);
-
-                    v = &m_src_vertices[2];
-                    dv.x1    = v->x;
-                    dv.y1    = v->y;
-                    dv.lnext = v->len;
-                    dv.curr = line_parameters(x2, y2, dv.x1, dv.y1, dv.lcurr);
-
-                    v = &m_src_vertices[dv.idx];
-                    dv.x2 = v->x;
-                    dv.y2 = v->y;
-                    dv.next = line_parameters(dv.x1, dv.y1, dv.x2, dv.y2, dv.lnext);
-
-                    dv.xb1 = 0;
-                    dv.yb1 = 0;
-                    dv.xb2 = 0;
-                    dv.yb2 = 0;
-
-                    switch(m_line_join)
-                    {
-                    case outline_no_join:
-                        dv.flags = 3;
-                        break;
-
-                    case outline_miter_join:
-                    case outline_round_join:
-                        dv.flags = 
-                                (prev.diagonal_quadrant() == dv.curr.diagonal_quadrant()) |
-                            ((dv.curr.diagonal_quadrant() == dv.next.diagonal_quadrant()) << 1);
-                        break;
-
-                    case outline_miter_accurate_join:
-                        dv.flags = 0;
-                        break;
-                    }
-
-                    if(m_round_cap) 
-                    {
-                        m_ren->semidot(cmp_dist_start, x1, y1, x1 + (y2 - y1), y1 - (x2 - x1));
-                    }
-                    if((dv.flags & 1) == 0)
-                    {
-                        if(m_line_join == outline_round_join)
-                        {
-                            m_ren->line3(prev, x1 + (y2 - y1), y1 - (x2 - x1),
-                                               x2 + (y2 - y1), y2 - (x2 - x1));
-                            m_ren->pie(prev.x2, prev.y2, 
-                                       x2 + (y2 - y1), y2 - (x2 - x1),
-                                       dv.curr.x1 + (dv.curr.y2 - dv.curr.y1), 
-                                       dv.curr.y1 - (dv.curr.x2 - dv.curr.x1));
-                        }
-                        else
-                        {
-                            bisectrix(prev, dv.curr, &dv.xb1, &dv.yb1);
-                            m_ren->line3(prev, x1 + (y2 - y1), y1 - (x2 - x1),
-                                               dv.xb1,         dv.yb1);
-                        }
-                    }
-                    else
-                    {
-                        m_ren->line1(prev, 
-                                     x1 + (y2 - y1), 
-                                     y1 - (x2 - x1));
-                    }
-                    if((dv.flags & 2) == 0 && m_line_join != outline_round_join)
-                    {
-                        bisectrix(dv.curr, dv.next, &dv.xb2, &dv.yb2);
-                    }
-
-                    draw(dv, 1, m_src_vertices.size() - 2);
-
-                    if((dv.flags & 1) == 0)
-                    {
-                        if(m_line_join == outline_round_join)
-                        {
-                            m_ren->line3(dv.curr, 
-                                         dv.curr.x1 + (dv.curr.y2 - dv.curr.y1), 
-                                         dv.curr.y1 - (dv.curr.x2 - dv.curr.x1),
-                                         dv.curr.x2 + (dv.curr.y2 - dv.curr.y1), 
-                                         dv.curr.y2 - (dv.curr.x2 - dv.curr.x1));
-                        }
-                        else
-                        {
-                            m_ren->line3(dv.curr, dv.xb1, dv.yb1,
-                                         dv.curr.x2 + (dv.curr.y2 - dv.curr.y1), 
-                                         dv.curr.y2 - (dv.curr.x2 - dv.curr.x1));
-                        }
-                    }
-                    else
-                    {
-                        m_ren->line2(dv.curr, 
-                                     dv.curr.x2 + (dv.curr.y2 - dv.curr.y1), 
-                                     dv.curr.y2 - (dv.curr.x2 - dv.curr.x1));
-                    }
-                    if(m_round_cap) 
-                    {
-                        m_ren->semidot(cmp_dist_end, dv.curr.x2, dv.curr.y2,
-                                       dv.curr.x2 + (dv.curr.y2 - dv.curr.y1),
-                                       dv.curr.y2 - (dv.curr.x2 - dv.curr.x1));
-                    }
-
-                }
-                break;
-            }
-        }
-        m_src_vertices.remove_all();
-    }
-
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_renderer_markers.h b/xs/src/agg/agg_renderer_markers.h
deleted file mode 100644
index 6ff053494..000000000
--- a/xs/src/agg/agg_renderer_markers.h
+++ /dev/null
@@ -1,711 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// class renderer_markers
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_RENDERER_MARKERS_INCLUDED
-#define AGG_RENDERER_MARKERS_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_renderer_primitives.h"
-
-namespace agg
-{
-
-    //---------------------------------------------------------------marker_e
-    enum marker_e
-    {
-        marker_square,
-        marker_diamond,
-        marker_circle,
-        marker_crossed_circle,
-        marker_semiellipse_left,
-        marker_semiellipse_right,
-        marker_semiellipse_up,
-        marker_semiellipse_down,
-        marker_triangle_left,
-        marker_triangle_right,
-        marker_triangle_up,
-        marker_triangle_down,
-        marker_four_rays,
-        marker_cross,
-        marker_x,
-        marker_dash,
-        marker_dot,
-        marker_pixel,
-        
-        end_of_markers
-    };
-
-
-
-    //--------------------------------------------------------renderer_markers
-    template<class BaseRenderer> class renderer_markers :
-    public renderer_primitives<BaseRenderer>
-    {
-    public:
-        typedef renderer_primitives<BaseRenderer> base_type;
-        typedef BaseRenderer base_ren_type;
-        typedef typename base_ren_type::color_type color_type;
-
-        //--------------------------------------------------------------------
-        renderer_markers(base_ren_type& rbuf) :
-            base_type(rbuf)
-        {}
-
-        //--------------------------------------------------------------------
-        bool visible(int x, int y, int r) const
-        {
-            rect_i rc(x-r, y-r, x+y, y+r);
-            return rc.clip(base_type::ren().bounding_clip_box());  
-        }
-
-        //--------------------------------------------------------------------
-        void square(int x, int y, int r)
-        {
-            if(visible(x, y, r)) 
-            {  
-                if(r) base_type::outlined_rectangle(x-r, y-r, x+r, y+r);
-                else  base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void diamond(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r;
-                    int dx = 0;
-                    do
-                    {
-                        base_type::ren().blend_pixel(x - dx, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dx, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dx, y - dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dx, y - dy, base_type::line_color(), cover_full);
-                        
-                        if(dx)
-                        {
-                            base_type::ren().blend_hline(x-dx+1, y+dy, x+dx-1, base_type::fill_color(), cover_full);
-                            base_type::ren().blend_hline(x-dx+1, y-dy, x+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++dy;
-                        ++dx;
-                    }
-                    while(dy <= 0);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void circle(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r) base_type::outlined_ellipse(x, y, r, r);
-                else  base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-            }
-        }
-
-
-
-        //--------------------------------------------------------------------
-        void crossed_circle(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    base_type::outlined_ellipse(x, y, r, r);
-                    int r6 = r + (r >> 1);
-                    if(r <= 2) r6++;
-                    r >>= 1;
-                    base_type::ren().blend_hline(x-r6, y, x-r,  base_type::line_color(), cover_full);
-                    base_type::ren().blend_hline(x+r,  y, x+r6, base_type::line_color(), cover_full);
-                    base_type::ren().blend_vline(x, y-r6, y-r,  base_type::line_color(), cover_full);
-                    base_type::ren().blend_vline(x, y+r,  y+r6, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //------------------------------------------------------------------------
-        void semiellipse_left(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int r8 = r * 4 / 5;
-                    int dy = -r;
-                    int dx = 0;
-                    ellipse_bresenham_interpolator ei(r * 3 / 5, r+r8);
-                    do
-                    {
-                        dx += ei.dx();
-                        dy += ei.dy();
-                        
-                        base_type::ren().blend_pixel(x + dy, y + dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dy, y - dx, base_type::line_color(), cover_full);
-                        
-                        if(ei.dy() && dx)
-                        {
-                            base_type::ren().blend_vline(x+dy, y-dx+1, y+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++ei;
-                    }
-                    while(dy < r8);
-                    base_type::ren().blend_vline(x+dy, y-dx, y+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void semiellipse_right(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int r8 = r * 4 / 5;
-                    int dy = -r;
-                    int dx = 0;
-                    ellipse_bresenham_interpolator ei(r * 3 / 5, r+r8);
-                    do
-                    {
-                        dx += ei.dx();
-                        dy += ei.dy();
-                        
-                        base_type::ren().blend_pixel(x - dy, y + dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dy, y - dx, base_type::line_color(), cover_full);
-                        
-                        if(ei.dy() && dx)
-                        {
-                            base_type::ren().blend_vline(x-dy, y-dx+1, y+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++ei;
-                    }
-                    while(dy < r8);
-                    base_type::ren().blend_vline(x-dy, y-dx, y+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void semiellipse_up(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int r8 = r * 4 / 5;
-                    int dy = -r;
-                    int dx = 0;
-                    ellipse_bresenham_interpolator ei(r * 3 / 5, r+r8);
-                    do
-                    {
-                        dx += ei.dx();
-                        dy += ei.dy();
-                        
-                        base_type::ren().blend_pixel(x + dx, y - dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dx, y - dy, base_type::line_color(), cover_full);
-                        
-                        if(ei.dy() && dx)
-                        {
-                            base_type::ren().blend_hline(x-dx+1, y-dy, x+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++ei;
-                    }
-                    while(dy < r8);
-                    base_type::ren().blend_hline(x-dx, y-dy-1, x+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void semiellipse_down(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int r8 = r * 4 / 5;
-                    int dy = -r;
-                    int dx = 0;
-                    ellipse_bresenham_interpolator ei(r * 3 / 5, r+r8);
-                    do
-                    {
-                        dx += ei.dx();
-                        dy += ei.dy();
-                        
-                        base_type::ren().blend_pixel(x + dx, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dx, y + dy, base_type::line_color(), cover_full);
-                        
-                        if(ei.dy() && dx)
-                        {
-                            base_type::ren().blend_hline(x-dx+1, y+dy, x+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++ei;
-                    }
-                    while(dy < r8);
-                    base_type::ren().blend_hline(x-dx, y+dy+1, x+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void triangle_left(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r;
-                    int dx = 0;
-                    int flip = 0;
-                    int r6 = r * 3 / 5;
-                    do
-                    {
-                        base_type::ren().blend_pixel(x + dy, y - dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dy, y + dx, base_type::line_color(), cover_full);
-                        
-                        if(dx)
-                        {
-                            base_type::ren().blend_vline(x+dy, y-dx+1, y+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++dy;
-                        dx += flip;
-                        flip ^= 1;
-                    }
-                    while(dy < r6);
-                    base_type::ren().blend_vline(x+dy, y-dx, y+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void triangle_right(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r;
-                    int dx = 0;
-                    int flip = 0;
-                    int r6 = r * 3 / 5;
-                    do
-                    {
-                        base_type::ren().blend_pixel(x - dy, y - dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dy, y + dx, base_type::line_color(), cover_full);
-                        
-                        if(dx)
-                        {
-                            base_type::ren().blend_vline(x-dy, y-dx+1, y+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++dy;
-                        dx += flip;
-                        flip ^= 1;
-                    }
-                    while(dy < r6);
-                    base_type::ren().blend_vline(x-dy, y-dx, y+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void triangle_up(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r;
-                    int dx = 0;
-                    int flip = 0;
-                    int r6 = r * 3 / 5;
-                    do
-                    {
-                        base_type::ren().blend_pixel(x - dx, y - dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dx, y - dy, base_type::line_color(), cover_full);
-                        
-                        if(dx)
-                        {
-                            base_type::ren().blend_hline(x-dx+1, y-dy, x+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++dy;
-                        dx += flip;
-                        flip ^= 1;
-                    }
-                    while(dy < r6);
-                    base_type::ren().blend_hline(x-dx, y-dy, x+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void triangle_down(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r;
-                    int dx = 0;
-                    int flip = 0;
-                    int r6 = r * 3 / 5;
-                    do
-                    {
-                        base_type::ren().blend_pixel(x - dx, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dx, y + dy, base_type::line_color(), cover_full);
-                        
-                        if(dx)
-                        {
-                            base_type::ren().blend_hline(x-dx+1, y+dy, x+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++dy;
-                        dx += flip;
-                        flip ^= 1;
-                    }
-                    while(dy < r6);
-                    base_type::ren().blend_hline(x-dx, y+dy, x+dx, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void four_rays(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r;
-                    int dx = 0;
-                    int flip = 0;
-                    int r3 = -(r / 3);
-                    do
-                    {
-                        base_type::ren().blend_pixel(x - dx, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dx, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dx, y - dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dx, y - dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dy, y - dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dy, y + dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dy, y - dx, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dy, y + dx, base_type::line_color(), cover_full);
-                        
-                        if(dx)
-                        {
-                            base_type::ren().blend_hline(x-dx+1, y+dy,   x+dx-1, base_type::fill_color(), cover_full);
-                            base_type::ren().blend_hline(x-dx+1, y-dy,   x+dx-1, base_type::fill_color(), cover_full);
-                            base_type::ren().blend_vline(x+dy,   y-dx+1, y+dx-1, base_type::fill_color(), cover_full);
-                            base_type::ren().blend_vline(x-dy,   y-dx+1, y+dx-1, base_type::fill_color(), cover_full);
-                        }
-                        ++dy;
-                        dx += flip;
-                        flip ^= 1;
-                    }
-                    while(dy <= r3);
-                    base_type::solid_rectangle(x+r3+1, y+r3+1, x-r3-1, y-r3-1);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        void cross(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    base_type::ren().blend_vline(x, y-r, y+r, base_type::line_color(), cover_full);
-                    base_type::ren().blend_hline(x-r, y, x+r, base_type::line_color(), cover_full);
-                }
-                else
-                {
-                    base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-                }
-            }
-        }
-        
-        
-        //--------------------------------------------------------------------
-        void xing(int x, int y, int r)
-        {
-            if(visible(x, y, r))
-            {
-                if(r)
-                {
-                    int dy = -r * 7 / 10;
-                    do
-                    {
-                        base_type::ren().blend_pixel(x + dy, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dy, y + dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x + dy, y - dy, base_type::line_color(), cover_full);
-                        base_type::ren().blend_pixel(x - dy, y - dy, base_type::line_color(), cover_full);
-                        ++dy;
-                    }
-                    while(dy < 0);
-                }
-                base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-            }
-        }
-        
-        
-        //--------------------------------------------------------------------
-        void dash(int x, int y, int r)
-        {
-            if(visible(x, y, r)) 
-            {
-                if(r) base_type::ren().blend_hline(x-r, y, x+r, base_type::line_color(), cover_full);
-                else  base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-            }
-        }
-        
-        
-        //--------------------------------------------------------------------
-        void dot(int x, int y, int r)
-        {
-            if(visible(x, y, r)) 
-            {
-                if(r) base_type::solid_ellipse(x, y, r, r);
-                else  base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-            }
-        }
-        
-        //--------------------------------------------------------------------
-        void pixel(int x, int y, int)
-        {
-            base_type::ren().blend_pixel(x, y, base_type::fill_color(), cover_full);
-        }
-        
-        //--------------------------------------------------------------------
-        void marker(int x, int y, int r, marker_e type)
-        {
-            switch(type)
-            {
-                case marker_square:            square(x, y, r);            break;
-                case marker_diamond:           diamond(x, y, r);           break;
-                case marker_circle:            circle(x, y, r);            break;
-                case marker_crossed_circle:    crossed_circle(x, y, r);    break;
-                case marker_semiellipse_left:  semiellipse_left(x, y, r);  break;
-                case marker_semiellipse_right: semiellipse_right(x, y, r); break;
-                case marker_semiellipse_up:    semiellipse_up(x, y, r);    break;
-                case marker_semiellipse_down:  semiellipse_down(x, y, r);  break;
-                case marker_triangle_left:     triangle_left(x, y, r);     break;
-                case marker_triangle_right:    triangle_right(x, y, r);    break;
-                case marker_triangle_up:       triangle_up(x, y, r);       break;
-                case marker_triangle_down:     triangle_down(x, y, r);     break;
-                case marker_four_rays:         four_rays(x, y, r);         break;
-                case marker_cross:             cross(x, y, r);             break;
-                case marker_x:                 xing(x, y, r);              break;
-                case marker_dash:              dash(x, y, r);              break;
-                case marker_dot:               dot(x, y, r);               break;
-                case marker_pixel:             pixel(x, y, r);             break;
-                case end_of_markers: break;
-            }
-        }
-
-
-        //--------------------------------------------------------------------
-        template<class T>
-        void markers(int n, const T* x, const T* y, T r, marker_e type)
-        {
-            if(n <= 0) return;
-            if(r == 0)
-            {
-                do
-                {
-                    base_type::ren().blend_pixel(int(*x), int(*y), base_type::fill_color(), cover_full);
-                    ++x;
-                    ++y;
-                }
-                while(--n);
-                return;
-            }
-            
-            switch(type)
-            {
-                case marker_square:            do { square           (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_diamond:           do { diamond          (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_circle:            do { circle           (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_crossed_circle:    do { crossed_circle   (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_semiellipse_left:  do { semiellipse_left (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_semiellipse_right: do { semiellipse_right(int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_semiellipse_up:    do { semiellipse_up   (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_semiellipse_down:  do { semiellipse_down (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_triangle_left:     do { triangle_left    (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_triangle_right:    do { triangle_right   (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_triangle_up:       do { triangle_up      (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_triangle_down:     do { triangle_down    (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_four_rays:         do { four_rays        (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_cross:             do { cross            (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_x:                 do { xing             (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_dash:              do { dash             (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_dot:               do { dot              (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case marker_pixel:             do { pixel            (int(*x), int(*y), int(r)); ++x; ++y; } while(--n); break;
-                case end_of_markers: break;
-            }                                                                                  
-        }
-        
-        //--------------------------------------------------------------------
-        template<class T>
-        void markers(int n, const T* x, const T* y, const T* r, marker_e type)
-        {
-            if(n <= 0) return;
-            switch(type)
-            {
-                case marker_square:            do { square           (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_diamond:           do { diamond          (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_circle:            do { circle           (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_crossed_circle:    do { crossed_circle   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_semiellipse_left:  do { semiellipse_left (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_semiellipse_right: do { semiellipse_right(int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_semiellipse_up:    do { semiellipse_up   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_semiellipse_down:  do { semiellipse_down (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_triangle_left:     do { triangle_left    (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_triangle_right:    do { triangle_right   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_triangle_up:       do { triangle_up      (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_triangle_down:     do { triangle_down    (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_four_rays:         do { four_rays        (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_cross:             do { cross            (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_x:                 do { xing             (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_dash:              do { dash             (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_dot:               do { dot              (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case marker_pixel:             do { pixel            (int(*x), int(*y), int(*r)); ++x; ++y; ++r; } while(--n); break;
-                case end_of_markers: break;
-            }                                                                                  
-        }
-        
-        //--------------------------------------------------------------------
-        template<class T>
-        void markers(int n, const T* x, const T* y, const T* r, const color_type* fc, marker_e type)
-        {
-            if(n <= 0) return;
-            switch(type)
-            {
-                case marker_square:            do { base_type::fill_color(*fc); square           (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_diamond:           do { base_type::fill_color(*fc); diamond          (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_circle:            do { base_type::fill_color(*fc); circle           (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_crossed_circle:    do { base_type::fill_color(*fc); crossed_circle   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_semiellipse_left:  do { base_type::fill_color(*fc); semiellipse_left (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_semiellipse_right: do { base_type::fill_color(*fc); semiellipse_right(int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_semiellipse_up:    do { base_type::fill_color(*fc); semiellipse_up   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_semiellipse_down:  do { base_type::fill_color(*fc); semiellipse_down (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_triangle_left:     do { base_type::fill_color(*fc); triangle_left    (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_triangle_right:    do { base_type::fill_color(*fc); triangle_right   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_triangle_up:       do { base_type::fill_color(*fc); triangle_up      (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_triangle_down:     do { base_type::fill_color(*fc); triangle_down    (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_four_rays:         do { base_type::fill_color(*fc); four_rays        (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_cross:             do { base_type::fill_color(*fc); cross            (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_x:                 do { base_type::fill_color(*fc); xing             (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_dash:              do { base_type::fill_color(*fc); dash             (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_dot:               do { base_type::fill_color(*fc); dot              (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case marker_pixel:             do { base_type::fill_color(*fc); pixel            (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; } while(--n); break;
-                case end_of_markers: break;
-            }
-        }
-        
-        //--------------------------------------------------------------------
-        template<class T>
-        void markers(int n, const T* x, const T* y, const T* r, const color_type* fc, const color_type* lc, marker_e type)
-        {
-            if(n <= 0) return;
-            switch(type)
-            {
-                case marker_square:            do { base_type::fill_color(*fc); base_type::line_color(*lc); square           (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_diamond:           do { base_type::fill_color(*fc); base_type::line_color(*lc); diamond          (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_circle:            do { base_type::fill_color(*fc); base_type::line_color(*lc); circle           (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_crossed_circle:    do { base_type::fill_color(*fc); base_type::line_color(*lc); crossed_circle   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_semiellipse_left:  do { base_type::fill_color(*fc); base_type::line_color(*lc); semiellipse_left (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_semiellipse_right: do { base_type::fill_color(*fc); base_type::line_color(*lc); semiellipse_right(int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_semiellipse_up:    do { base_type::fill_color(*fc); base_type::line_color(*lc); semiellipse_up   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_semiellipse_down:  do { base_type::fill_color(*fc); base_type::line_color(*lc); semiellipse_down (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_triangle_left:     do { base_type::fill_color(*fc); base_type::line_color(*lc); triangle_left    (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_triangle_right:    do { base_type::fill_color(*fc); base_type::line_color(*lc); triangle_right   (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_triangle_up:       do { base_type::fill_color(*fc); base_type::line_color(*lc); triangle_up      (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_triangle_down:     do { base_type::fill_color(*fc); base_type::line_color(*lc); triangle_down    (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_four_rays:         do { base_type::fill_color(*fc); base_type::line_color(*lc); four_rays        (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_cross:             do { base_type::fill_color(*fc); base_type::line_color(*lc); cross            (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_x:                 do { base_type::fill_color(*fc); base_type::line_color(*lc); xing             (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_dash:              do { base_type::fill_color(*fc); base_type::line_color(*lc); dash             (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_dot:               do { base_type::fill_color(*fc); base_type::line_color(*lc); dot              (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case marker_pixel:             do { base_type::fill_color(*fc); base_type::line_color(*lc); pixel            (int(*x), int(*y), int(*r)); ++x; ++y; ++r; ++fc; ++lc; } while(--n); break;
-                case end_of_markers: break;
-            }
-        }
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_renderer_mclip.h b/xs/src/agg/agg_renderer_mclip.h
deleted file mode 100644
index 96a7d4e09..000000000
--- a/xs/src/agg/agg_renderer_mclip.h
+++ /dev/null
@@ -1,349 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// class renderer_mclip
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_RENDERER_MCLIP_INCLUDED
-#define AGG_RENDERER_MCLIP_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_array.h"
-#include "agg_renderer_base.h"
-
-namespace agg
-{
-
-    //----------------------------------------------------------renderer_mclip
-    template<class PixelFormat> class renderer_mclip
-    {
-    public:
-        typedef PixelFormat pixfmt_type;
-        typedef typename pixfmt_type::color_type color_type;
-        typedef typename pixfmt_type::row_data row_data;
-        typedef renderer_base<pixfmt_type> base_ren_type;
-
-        //--------------------------------------------------------------------
-        explicit renderer_mclip(pixfmt_type& pixf) :
-            m_ren(pixf),
-            m_curr_cb(0),
-            m_bounds(m_ren.xmin(), m_ren.ymin(), m_ren.xmax(), m_ren.ymax())
-        {}
-        void attach(pixfmt_type& pixf)
-        {
-            m_ren.attach(pixf);
-            reset_clipping(true);
-        }
-          
-        //--------------------------------------------------------------------
-        const pixfmt_type& ren() const { return m_ren.ren();  }
-        pixfmt_type& ren() { return m_ren.ren();  }
-
-        //--------------------------------------------------------------------
-        unsigned width()  const { return m_ren.width();  }
-        unsigned height() const { return m_ren.height(); }
-
-        //--------------------------------------------------------------------
-        const rect_i& clip_box() const { return m_ren.clip_box(); }
-        int           xmin()     const { return m_ren.xmin(); }
-        int           ymin()     const { return m_ren.ymin(); }
-        int           xmax()     const { return m_ren.xmax(); }
-        int           ymax()     const { return m_ren.ymax(); }
-
-        //--------------------------------------------------------------------
-        const rect_i& bounding_clip_box() const { return m_bounds;    }
-        int           bounding_xmin()     const { return m_bounds.x1; }
-        int           bounding_ymin()     const { return m_bounds.y1; }
-        int           bounding_xmax()     const { return m_bounds.x2; }
-        int           bounding_ymax()     const { return m_bounds.y2; }
-
-        //--------------------------------------------------------------------
-        void first_clip_box() 
-        {
-            m_curr_cb = 0;
-            if(m_clip.size())
-            {
-                const rect_i& cb = m_clip[0];
-                m_ren.clip_box_naked(cb.x1, cb.y1, cb.x2, cb.y2);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        bool next_clip_box() 
-        { 
-            if(++m_curr_cb < m_clip.size())
-            {
-                const rect_i& cb = m_clip[m_curr_cb];
-                m_ren.clip_box_naked(cb.x1, cb.y1, cb.x2, cb.y2);
-                return true;
-            }
-            return false; 
-        }
-
-        //--------------------------------------------------------------------
-        void reset_clipping(bool visibility)
-        {
-            m_ren.reset_clipping(visibility);
-            m_clip.remove_all();
-            m_curr_cb = 0;
-            m_bounds = m_ren.clip_box();
-        }
-        
-        //--------------------------------------------------------------------
-        void add_clip_box(int x1, int y1, int x2, int y2)
-        {
-            rect_i cb(x1, y1, x2, y2); 
-            cb.normalize();
-            if(cb.clip(rect_i(0, 0, width() - 1, height() - 1)))
-            {
-                m_clip.add(cb);
-                if(cb.x1 < m_bounds.x1) m_bounds.x1 = cb.x1;
-                if(cb.y1 < m_bounds.y1) m_bounds.y1 = cb.y1;
-                if(cb.x2 > m_bounds.x2) m_bounds.x2 = cb.x2;
-                if(cb.y2 > m_bounds.y2) m_bounds.y2 = cb.y2;
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void clear(const color_type& c)
-        {
-            m_ren.clear(c);
-        }
-          
-        //--------------------------------------------------------------------
-        void copy_pixel(int x, int y, const color_type& c)
-        {
-            first_clip_box();
-            do
-            {
-                if(m_ren.inbox(x, y))
-                {
-                    m_ren.ren().copy_pixel(x, y, c);
-                    break;
-                }
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_pixel(int x, int y, const color_type& c, cover_type cover)
-        {
-            first_clip_box();
-            do
-            {
-                if(m_ren.inbox(x, y))
-                {
-                    m_ren.ren().blend_pixel(x, y, c, cover);
-                    break;
-                }
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        color_type pixel(int x, int y) const
-        {
-            first_clip_box();
-            do
-            {
-                if(m_ren.inbox(x, y))
-                {
-                    return m_ren.ren().pixel(x, y);
-                }
-            }
-            while(next_clip_box());
-            return color_type::no_color();
-        }
-
-        //--------------------------------------------------------------------
-        void copy_hline(int x1, int y, int x2, const color_type& c)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.copy_hline(x1, y, x2, c);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void copy_vline(int x, int y1, int y2, const color_type& c)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.copy_vline(x, y1, y2, c);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_hline(int x1, int y, int x2, 
-                         const color_type& c, cover_type cover)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_hline(x1, y, x2, c, cover);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_vline(int x, int y1, int y2, 
-                         const color_type& c, cover_type cover)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_vline(x, y1, y2, c, cover);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void copy_bar(int x1, int y1, int x2, int y2, const color_type& c)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.copy_bar(x1, y1, x2, y2, c);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_bar(int x1, int y1, int x2, int y2, 
-                       const color_type& c, cover_type cover)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_bar(x1, y1, x2, y2, c, cover);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_solid_hspan(int x, int y, int len, 
-                               const color_type& c, const cover_type* covers)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_solid_hspan(x, y, len, c, covers);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_solid_vspan(int x, int y, int len, 
-                               const color_type& c, const cover_type* covers)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_solid_vspan(x, y, len, c, covers);
-            }
-            while(next_clip_box());
-        }
-
-
-        //--------------------------------------------------------------------
-        void copy_color_hspan(int x, int y, int len, const color_type* colors)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.copy_color_hspan(x, y, len, colors);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_hspan(int x, int y, int len, 
-                               const color_type* colors, 
-                               const cover_type* covers,
-                               cover_type cover = cover_full)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_color_hspan(x, y, len, colors, covers, cover);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void blend_color_vspan(int x, int y, int len, 
-                               const color_type* colors, 
-                               const cover_type* covers,
-                               cover_type cover = cover_full)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_color_vspan(x, y, len, colors, covers, cover);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        void copy_from(const rendering_buffer& from, 
-                       const rect_i* rc=0, 
-                       int x_to=0, 
-                       int y_to=0)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.copy_from(from, rc, x_to, y_to);
-            }
-            while(next_clip_box());
-        }
-
-        //--------------------------------------------------------------------
-        template<class SrcPixelFormatRenderer>
-        void blend_from(const SrcPixelFormatRenderer& src, 
-                        const rect_i* rect_src_ptr = 0, 
-                        int dx = 0, 
-                        int dy = 0,
-                        cover_type cover = cover_full)
-        {
-            first_clip_box();
-            do
-            {
-                m_ren.blend_from(src, rect_src_ptr, dx, dy, cover);
-            }
-            while(next_clip_box());
-        }
-
-        
-    private:
-        renderer_mclip(const renderer_mclip<PixelFormat>&);
-        const renderer_mclip<PixelFormat>& 
-            operator = (const renderer_mclip<PixelFormat>&);
-
-        base_ren_type          m_ren;
-        pod_bvector<rect_i, 4> m_clip;
-        unsigned               m_curr_cb;
-        rect_i                 m_bounds;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_renderer_outline_aa.h b/xs/src/agg/agg_renderer_outline_aa.h
deleted file mode 100644
index 394c58ca6..000000000
--- a/xs/src/agg/agg_renderer_outline_aa.h
+++ /dev/null
@@ -1,1836 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_RENDERER_OUTLINE_AA_INCLUDED
-#define AGG_RENDERER_OUTLINE_AA_INCLUDED
-
-#include "agg_array.h"
-#include "agg_math.h"
-#include "agg_line_aa_basics.h"
-#include "agg_dda_line.h"
-#include "agg_ellipse_bresenham.h"
-#include "agg_renderer_base.h"
-#include "agg_gamma_functions.h"
-#include "agg_clip_liang_barsky.h"
-
-namespace agg
-{
-
-    //===================================================distance_interpolator0
-    class distance_interpolator0
-    {
-    public:
-        //---------------------------------------------------------------------
-        distance_interpolator0() {}
-        distance_interpolator0(int x1, int y1, int x2, int y2, int x, int y) :
-            m_dx(line_mr(x2) - line_mr(x1)),
-            m_dy(line_mr(y2) - line_mr(y1)),
-            m_dist((line_mr(x + line_subpixel_scale/2) - line_mr(x2)) * m_dy - 
-                   (line_mr(y + line_subpixel_scale/2) - line_mr(y2)) * m_dx)
-        {
-            m_dx <<= line_mr_subpixel_shift;
-            m_dy <<= line_mr_subpixel_shift;
-        }
-
-        //---------------------------------------------------------------------
-        void inc_x() { m_dist += m_dy; }
-        int  dist() const { return m_dist; }
-
-    private:
-        //---------------------------------------------------------------------
-        int m_dx;
-        int m_dy;
-        int m_dist;
-    };
-
-    //==================================================distance_interpolator00
-    class distance_interpolator00
-    {
-    public:
-        //---------------------------------------------------------------------
-        distance_interpolator00() {}
-        distance_interpolator00(int xc, int yc, 
-                                int x1, int y1, int x2, int y2, 
-                                int x,  int y) :
-            m_dx1(line_mr(x1) - line_mr(xc)),
-            m_dy1(line_mr(y1) - line_mr(yc)),
-            m_dx2(line_mr(x2) - line_mr(xc)),
-            m_dy2(line_mr(y2) - line_mr(yc)),
-            m_dist1((line_mr(x + line_subpixel_scale/2) - line_mr(x1)) * m_dy1 - 
-                    (line_mr(y + line_subpixel_scale/2) - line_mr(y1)) * m_dx1),
-            m_dist2((line_mr(x + line_subpixel_scale/2) - line_mr(x2)) * m_dy2 - 
-                    (line_mr(y + line_subpixel_scale/2) - line_mr(y2)) * m_dx2)
-        {
-            m_dx1 <<= line_mr_subpixel_shift;
-            m_dy1 <<= line_mr_subpixel_shift;
-            m_dx2 <<= line_mr_subpixel_shift;
-            m_dy2 <<= line_mr_subpixel_shift;
-        }
-
-        //---------------------------------------------------------------------
-        void inc_x() { m_dist1 += m_dy1; m_dist2 += m_dy2; }
-        int  dist1() const { return m_dist1; }
-        int  dist2() const { return m_dist2; }
-
-    private:
-        //---------------------------------------------------------------------
-        int m_dx1;
-        int m_dy1;
-        int m_dx2;
-        int m_dy2;
-        int m_dist1;
-        int m_dist2;
-    };
-
-    //===================================================distance_interpolator1
-    class distance_interpolator1
-    {
-    public:
-        //---------------------------------------------------------------------
-        distance_interpolator1() {}
-        distance_interpolator1(int x1, int y1, int x2, int y2, int x, int y) :
-            m_dx(x2 - x1),
-            m_dy(y2 - y1),
-            m_dist(iround(double(x + line_subpixel_scale/2 - x2) * double(m_dy) - 
-                          double(y + line_subpixel_scale/2 - y2) * double(m_dx)))
-        {
-            m_dx <<= line_subpixel_shift;
-            m_dy <<= line_subpixel_shift;
-        }
-
-        //---------------------------------------------------------------------
-        void inc_x() { m_dist += m_dy; }
-        void dec_x() { m_dist -= m_dy; }
-        void inc_y() { m_dist -= m_dx; }
-        void dec_y() { m_dist += m_dx; }
-
-        //---------------------------------------------------------------------
-        void inc_x(int dy)
-        {
-            m_dist += m_dy; 
-            if(dy > 0) m_dist -= m_dx; 
-            if(dy < 0) m_dist += m_dx; 
-        }
-
-        //---------------------------------------------------------------------
-        void dec_x(int dy)
-        {
-            m_dist -= m_dy; 
-            if(dy > 0) m_dist -= m_dx; 
-            if(dy < 0) m_dist += m_dx; 
-        }
-
-        //---------------------------------------------------------------------
-        void inc_y(int dx)
-        {
-            m_dist -= m_dx; 
-            if(dx > 0) m_dist += m_dy; 
-            if(dx < 0) m_dist -= m_dy; 
-        }
-
-        void dec_y(int dx)
-        //---------------------------------------------------------------------
-        {
-            m_dist += m_dx; 
-            if(dx > 0) m_dist += m_dy; 
-            if(dx < 0) m_dist -= m_dy; 
-        }
-
-        //---------------------------------------------------------------------
-        int dist() const { return m_dist; }
-        int dx()   const { return m_dx;   }
-        int dy()   const { return m_dy;   }
-
-    private:
-        //---------------------------------------------------------------------
-        int m_dx;
-        int m_dy;
-        int m_dist;
-    };
-
-
-
-
-
-    //===================================================distance_interpolator2
-    class distance_interpolator2
-    {
-    public:
-        //---------------------------------------------------------------------
-        distance_interpolator2() {}
-        distance_interpolator2(int x1, int y1, int x2, int y2,
-                               int sx, int sy, int x,  int y) :
-            m_dx(x2 - x1),
-            m_dy(y2 - y1),
-            m_dx_start(line_mr(sx) - line_mr(x1)),
-            m_dy_start(line_mr(sy) - line_mr(y1)),
-
-            m_dist(iround(double(x + line_subpixel_scale/2 - x2) * double(m_dy) - 
-                          double(y + line_subpixel_scale/2 - y2) * double(m_dx))),
-
-            m_dist_start((line_mr(x + line_subpixel_scale/2) - line_mr(sx)) * m_dy_start - 
-                         (line_mr(y + line_subpixel_scale/2) - line_mr(sy)) * m_dx_start)
-        {
-            m_dx       <<= line_subpixel_shift;
-            m_dy       <<= line_subpixel_shift;
-            m_dx_start <<= line_mr_subpixel_shift;
-            m_dy_start <<= line_mr_subpixel_shift;
-        }
-
-        distance_interpolator2(int x1, int y1, int x2, int y2,
-                               int ex, int ey, int x,  int y, int) :
-            m_dx(x2 - x1),
-            m_dy(y2 - y1),
-            m_dx_start(line_mr(ex) - line_mr(x2)),
-            m_dy_start(line_mr(ey) - line_mr(y2)),
-
-            m_dist(iround(double(x + line_subpixel_scale/2 - x2) * double(m_dy) - 
-                          double(y + line_subpixel_scale/2 - y2) * double(m_dx))),
-
-            m_dist_start((line_mr(x + line_subpixel_scale/2) - line_mr(ex)) * m_dy_start - 
-                         (line_mr(y + line_subpixel_scale/2) - line_mr(ey)) * m_dx_start)
-        {
-            m_dx       <<= line_subpixel_shift;
-            m_dy       <<= line_subpixel_shift;
-            m_dx_start <<= line_mr_subpixel_shift;
-            m_dy_start <<= line_mr_subpixel_shift;
-        }
-
-
-        //---------------------------------------------------------------------
-        void inc_x() { m_dist += m_dy; m_dist_start += m_dy_start; }
-        void dec_x() { m_dist -= m_dy; m_dist_start -= m_dy_start; }
-        void inc_y() { m_dist -= m_dx; m_dist_start -= m_dx_start; }
-        void dec_y() { m_dist += m_dx; m_dist_start += m_dx_start; }
-
-        //---------------------------------------------------------------------
-        void inc_x(int dy)
-        {
-            m_dist       += m_dy; 
-            m_dist_start += m_dy_start; 
-            if(dy > 0)
-            {
-                m_dist       -= m_dx; 
-                m_dist_start -= m_dx_start; 
-            }
-            if(dy < 0)
-            {
-                m_dist       += m_dx; 
-                m_dist_start += m_dx_start; 
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void dec_x(int dy)
-        {
-            m_dist       -= m_dy; 
-            m_dist_start -= m_dy_start; 
-            if(dy > 0)
-            {
-                m_dist       -= m_dx; 
-                m_dist_start -= m_dx_start; 
-            }
-            if(dy < 0)
-            {
-                m_dist       += m_dx; 
-                m_dist_start += m_dx_start; 
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void inc_y(int dx)
-        {
-            m_dist       -= m_dx; 
-            m_dist_start -= m_dx_start; 
-            if(dx > 0)
-            {
-                m_dist       += m_dy; 
-                m_dist_start += m_dy_start; 
-            }
-            if(dx < 0)
-            {
-                m_dist       -= m_dy; 
-                m_dist_start -= m_dy_start; 
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void dec_y(int dx)
-        {
-            m_dist       += m_dx; 
-            m_dist_start += m_dx_start; 
-            if(dx > 0)
-            {
-                m_dist       += m_dy; 
-                m_dist_start += m_dy_start; 
-            }
-            if(dx < 0)
-            {
-                m_dist       -= m_dy; 
-                m_dist_start -= m_dy_start; 
-            }
-        }
-
-        //---------------------------------------------------------------------
-        int dist()       const { return m_dist;       }
-        int dist_start() const { return m_dist_start; }
-        int dist_end()   const { return m_dist_start; }
-
-        //---------------------------------------------------------------------
-        int dx()       const { return m_dx;       }
-        int dy()       const { return m_dy;       }
-        int dx_start() const { return m_dx_start; }
-        int dy_start() const { return m_dy_start; }
-        int dx_end()   const { return m_dx_start; }
-        int dy_end()   const { return m_dy_start; }
-
-    private:
-        //---------------------------------------------------------------------
-        int m_dx;
-        int m_dy;
-        int m_dx_start;
-        int m_dy_start;
-
-        int m_dist;
-        int m_dist_start;
-    };
-
-
-
-
-
-    //===================================================distance_interpolator3
-    class distance_interpolator3
-    {
-    public:
-        //---------------------------------------------------------------------
-        distance_interpolator3() {}
-        distance_interpolator3(int x1, int y1, int x2, int y2,
-                               int sx, int sy, int ex, int ey, 
-                               int x,  int y) :
-            m_dx(x2 - x1),
-            m_dy(y2 - y1),
-            m_dx_start(line_mr(sx) - line_mr(x1)),
-            m_dy_start(line_mr(sy) - line_mr(y1)),
-            m_dx_end(line_mr(ex) - line_mr(x2)),
-            m_dy_end(line_mr(ey) - line_mr(y2)),
-
-            m_dist(iround(double(x + line_subpixel_scale/2 - x2) * double(m_dy) - 
-                          double(y + line_subpixel_scale/2 - y2) * double(m_dx))),
-
-            m_dist_start((line_mr(x + line_subpixel_scale/2) - line_mr(sx)) * m_dy_start - 
-                         (line_mr(y + line_subpixel_scale/2) - line_mr(sy)) * m_dx_start),
-
-            m_dist_end((line_mr(x + line_subpixel_scale/2) - line_mr(ex)) * m_dy_end - 
-                       (line_mr(y + line_subpixel_scale/2) - line_mr(ey)) * m_dx_end)
-        {
-            m_dx       <<= line_subpixel_shift;
-            m_dy       <<= line_subpixel_shift;
-            m_dx_start <<= line_mr_subpixel_shift;
-            m_dy_start <<= line_mr_subpixel_shift;
-            m_dx_end   <<= line_mr_subpixel_shift;
-            m_dy_end   <<= line_mr_subpixel_shift;
-        }
-
-        //---------------------------------------------------------------------
-        void inc_x() { m_dist += m_dy; m_dist_start += m_dy_start; m_dist_end += m_dy_end; }
-        void dec_x() { m_dist -= m_dy; m_dist_start -= m_dy_start; m_dist_end -= m_dy_end; }
-        void inc_y() { m_dist -= m_dx; m_dist_start -= m_dx_start; m_dist_end -= m_dx_end; }
-        void dec_y() { m_dist += m_dx; m_dist_start += m_dx_start; m_dist_end += m_dx_end; }
-
-        //---------------------------------------------------------------------
-        void inc_x(int dy)
-        {
-            m_dist       += m_dy; 
-            m_dist_start += m_dy_start; 
-            m_dist_end   += m_dy_end;
-            if(dy > 0)
-            {
-                m_dist       -= m_dx; 
-                m_dist_start -= m_dx_start; 
-                m_dist_end   -= m_dx_end;
-            }
-            if(dy < 0)
-            {
-                m_dist       += m_dx; 
-                m_dist_start += m_dx_start; 
-                m_dist_end   += m_dx_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void dec_x(int dy)
-        {
-            m_dist       -= m_dy; 
-            m_dist_start -= m_dy_start; 
-            m_dist_end   -= m_dy_end;
-            if(dy > 0)
-            {
-                m_dist       -= m_dx; 
-                m_dist_start -= m_dx_start; 
-                m_dist_end   -= m_dx_end;
-            }
-            if(dy < 0)
-            {
-                m_dist       += m_dx; 
-                m_dist_start += m_dx_start; 
-                m_dist_end   += m_dx_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void inc_y(int dx)
-        {
-            m_dist       -= m_dx; 
-            m_dist_start -= m_dx_start; 
-            m_dist_end   -= m_dx_end;
-            if(dx > 0)
-            {
-                m_dist       += m_dy; 
-                m_dist_start += m_dy_start; 
-                m_dist_end   += m_dy_end;
-            }
-            if(dx < 0)
-            {
-                m_dist       -= m_dy; 
-                m_dist_start -= m_dy_start; 
-                m_dist_end   -= m_dy_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void dec_y(int dx)
-        {
-            m_dist       += m_dx; 
-            m_dist_start += m_dx_start; 
-            m_dist_end   += m_dx_end;
-            if(dx > 0)
-            {
-                m_dist       += m_dy; 
-                m_dist_start += m_dy_start; 
-                m_dist_end   += m_dy_end;
-            }
-            if(dx < 0)
-            {
-                m_dist       -= m_dy; 
-                m_dist_start -= m_dy_start; 
-                m_dist_end   -= m_dy_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        int dist()       const { return m_dist;       }
-        int dist_start() const { return m_dist_start; }
-        int dist_end()   const { return m_dist_end;   }
-
-        //---------------------------------------------------------------------
-        int dx()       const { return m_dx;       }
-        int dy()       const { return m_dy;       }
-        int dx_start() const { return m_dx_start; }
-        int dy_start() const { return m_dy_start; }
-        int dx_end()   const { return m_dx_end;   }
-        int dy_end()   const { return m_dy_end;   }
-
-    private:
-        //---------------------------------------------------------------------
-        int m_dx;
-        int m_dy;
-        int m_dx_start;
-        int m_dy_start;
-        int m_dx_end;
-        int m_dy_end;
-
-        int m_dist;
-        int m_dist_start;
-        int m_dist_end;
-    };
-
-
-
-
-    
-    //================================================line_interpolator_aa_base
-    template<class Renderer> class line_interpolator_aa_base
-    {
-    public:
-        typedef Renderer renderer_type;
-        typedef typename Renderer::color_type color_type;
-
-        //---------------------------------------------------------------------
-        enum max_half_width_e
-        { 
-            max_half_width = 64
-        };
-
-        //---------------------------------------------------------------------
-        line_interpolator_aa_base(renderer_type& ren, line_parameters& lp) :
-            m_lp(&lp),
-            m_li(lp.vertical ? line_dbl_hr(lp.x2 - lp.x1) :
-                               line_dbl_hr(lp.y2 - lp.y1),
-                 lp.vertical ? abs(lp.y2 - lp.y1) : 
-                               abs(lp.x2 - lp.x1) + 1),
-            m_ren(ren),
-            m_len((lp.vertical == (lp.inc > 0)) ? -lp.len : lp.len),
-            m_x(lp.x1 >> line_subpixel_shift),
-            m_y(lp.y1 >> line_subpixel_shift),
-            m_old_x(m_x),
-            m_old_y(m_y),
-            m_count((lp.vertical ? abs((lp.y2 >> line_subpixel_shift) - m_y) :
-                                   abs((lp.x2 >> line_subpixel_shift) - m_x))),
-            m_width(ren.subpixel_width()),
-            //m_max_extent(m_width >> (line_subpixel_shift - 2)),
-            m_max_extent((m_width + line_subpixel_mask) >> line_subpixel_shift),
-            m_step(0)
-        {
-            agg::dda2_line_interpolator li(0, lp.vertical ? 
-                                              (lp.dy << agg::line_subpixel_shift) :
-                                              (lp.dx << agg::line_subpixel_shift),
-                                           lp.len);
-
-            unsigned i;
-            int stop = m_width + line_subpixel_scale * 2;
-            for(i = 0; i < max_half_width; ++i)
-            {
-                m_dist[i] = li.y();
-                if(m_dist[i] >= stop) break;
-                ++li;
-            }
-            m_dist[i++] = 0x7FFF0000;
-        }
-
-        //---------------------------------------------------------------------
-        template<class DI> int step_hor_base(DI& di)
-        {
-            ++m_li;
-            m_x += m_lp->inc;
-            m_y = (m_lp->y1 + m_li.y()) >> line_subpixel_shift;
-
-            if(m_lp->inc > 0) di.inc_x(m_y - m_old_y);
-            else              di.dec_x(m_y - m_old_y);
-
-            m_old_y = m_y;
-
-            return di.dist() / m_len;
-        }
-
-        //---------------------------------------------------------------------
-        template<class DI> int step_ver_base(DI& di)
-        {
-            ++m_li;
-            m_y += m_lp->inc;
-            m_x = (m_lp->x1 + m_li.y()) >> line_subpixel_shift;
-
-            if(m_lp->inc > 0) di.inc_y(m_x - m_old_x);
-            else              di.dec_y(m_x - m_old_x);
-
-            m_old_x = m_x;
-
-            return di.dist() / m_len;
-        }
-
-        //---------------------------------------------------------------------
-        bool vertical() const { return m_lp->vertical; }
-        int  width() const { return m_width; }
-        int  count() const { return m_count; }
-
-    private:
-        line_interpolator_aa_base(const line_interpolator_aa_base<Renderer>&);
-        const line_interpolator_aa_base<Renderer>& 
-            operator = (const line_interpolator_aa_base<Renderer>&);
-
-    protected:
-        line_parameters* m_lp;
-        dda2_line_interpolator m_li;
-        renderer_type&         m_ren;
-        int m_len;
-        int m_x;
-        int m_y;
-        int m_old_x;
-        int m_old_y;
-        int m_count;
-        int m_width;
-        int m_max_extent;
-        int m_step;
-        int m_dist[max_half_width + 1];
-        cover_type m_covers[max_half_width * 2 + 4];
-    };
-
-
-
-
-
-
-
-    //====================================================line_interpolator_aa0
-    template<class Renderer> class line_interpolator_aa0 :
-    public line_interpolator_aa_base<Renderer>
-    {
-    public:
-        typedef Renderer renderer_type;
-        typedef typename Renderer::color_type color_type;
-        typedef line_interpolator_aa_base<Renderer> base_type;
-
-        //---------------------------------------------------------------------
-        line_interpolator_aa0(renderer_type& ren, line_parameters& lp) :
-            line_interpolator_aa_base<Renderer>(ren, lp),
-            m_di(lp.x1, lp.y1, lp.x2, lp.y2, 
-                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask)
-        {
-            base_type::m_li.adjust_forward();
-        }
-
-        //---------------------------------------------------------------------
-        bool step_hor()
-        {
-            int dist;
-            int dy;
-            int s1 = base_type::step_hor_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            *p1++ = (cover_type)base_type::m_ren.cover(s1);
-
-            dy = 1;
-            while((dist = base_type::m_dist[dy] - s1) <= base_type::m_width)
-            {
-                *p1++ = (cover_type)base_type::m_ren.cover(dist);
-                ++dy;
-            }
-
-            dy = 1;
-            while((dist = base_type::m_dist[dy] + s1) <= base_type::m_width)
-            {
-                *--p0 = (cover_type)base_type::m_ren.cover(dist);
-                ++dy;
-            }
-            base_type::m_ren.blend_solid_vspan(base_type::m_x, 
-                                               base_type::m_y - dy + 1, 
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return ++base_type::m_step < base_type::m_count;
-        }
-
-        //---------------------------------------------------------------------
-        bool step_ver()
-        {
-            int dist;
-            int dx;
-            int s1 = base_type::step_ver_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            *p1++ = (cover_type)base_type::m_ren.cover(s1);
-
-            dx = 1;
-            while((dist = base_type::m_dist[dx] - s1) <= base_type::m_width)
-            {
-                *p1++ = (cover_type)base_type::m_ren.cover(dist);
-                ++dx;
-            }
-
-            dx = 1;
-            while((dist = base_type::m_dist[dx] + s1) <= base_type::m_width)
-            {
-                *--p0 = (cover_type)base_type::m_ren.cover(dist);
-                ++dx;
-            }
-            base_type::m_ren.blend_solid_hspan(base_type::m_x - dx + 1, 
-                                               base_type::m_y,
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return ++base_type::m_step < base_type::m_count;
-        }
-
-    private:
-        line_interpolator_aa0(const line_interpolator_aa0<Renderer>&);
-        const line_interpolator_aa0<Renderer>& 
-            operator = (const line_interpolator_aa0<Renderer>&);
-
-        //---------------------------------------------------------------------
-        distance_interpolator1 m_di; 
-    };
-
-
-
-
-
-
-    //====================================================line_interpolator_aa1
-    template<class Renderer> class line_interpolator_aa1 :
-    public line_interpolator_aa_base<Renderer>
-    {
-    public:
-        typedef Renderer renderer_type;
-        typedef typename Renderer::color_type color_type;
-        typedef line_interpolator_aa_base<Renderer> base_type;
-
-        //---------------------------------------------------------------------
-        line_interpolator_aa1(renderer_type& ren, line_parameters& lp, 
-                              int sx, int sy) :
-            line_interpolator_aa_base<Renderer>(ren, lp),
-            m_di(lp.x1, lp.y1, lp.x2, lp.y2, sx, sy,
-                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask)
-        {
-            int dist1_start;
-            int dist2_start;
-
-            int npix = 1;
-
-            if(lp.vertical)
-            {
-                do
-                {
-                    --base_type::m_li;
-                    base_type::m_y -= lp.inc;
-                    base_type::m_x = (base_type::m_lp->x1 + base_type::m_li.y()) >> line_subpixel_shift;
-
-                    if(lp.inc > 0) m_di.dec_y(base_type::m_x - base_type::m_old_x);
-                    else           m_di.inc_y(base_type::m_x - base_type::m_old_x);
-
-                    base_type::m_old_x = base_type::m_x;
-
-                    dist1_start = dist2_start = m_di.dist_start(); 
-
-                    int dx = 0;
-                    if(dist1_start < 0) ++npix;
-                    do
-                    {
-                        dist1_start += m_di.dy_start();
-                        dist2_start -= m_di.dy_start();
-                        if(dist1_start < 0) ++npix;
-                        if(dist2_start < 0) ++npix;
-                        ++dx;
-                    }
-                    while(base_type::m_dist[dx] <= base_type::m_width);
-                    --base_type::m_step;
-                    if(npix == 0) break;
-                    npix = 0;
-                }
-                while(base_type::m_step >= -base_type::m_max_extent);
-            }
-            else
-            {
-                do
-                {
-                    --base_type::m_li;
-                    base_type::m_x -= lp.inc;
-                    base_type::m_y = (base_type::m_lp->y1 + base_type::m_li.y()) >> line_subpixel_shift;
-
-                    if(lp.inc > 0) m_di.dec_x(base_type::m_y - base_type::m_old_y);
-                    else           m_di.inc_x(base_type::m_y - base_type::m_old_y);
-
-                    base_type::m_old_y = base_type::m_y;
-
-                    dist1_start = dist2_start = m_di.dist_start(); 
-
-                    int dy = 0;
-                    if(dist1_start < 0) ++npix;
-                    do
-                    {
-                        dist1_start -= m_di.dx_start();
-                        dist2_start += m_di.dx_start();
-                        if(dist1_start < 0) ++npix;
-                        if(dist2_start < 0) ++npix;
-                        ++dy;
-                    }
-                    while(base_type::m_dist[dy] <= base_type::m_width);
-                    --base_type::m_step;
-                    if(npix == 0) break;
-                    npix = 0;
-                }
-                while(base_type::m_step >= -base_type::m_max_extent);
-            }
-            base_type::m_li.adjust_forward();
-        }
-
-        //---------------------------------------------------------------------
-        bool step_hor()
-        {
-            int dist_start;
-            int dist;
-            int dy;
-            int s1 = base_type::step_hor_base(m_di);
-
-            dist_start = m_di.dist_start();
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            *p1 = 0;
-            if(dist_start <= 0)
-            {
-                *p1 = (cover_type)base_type::m_ren.cover(s1);
-            }
-            ++p1;
-
-            dy = 1;
-            while((dist = base_type::m_dist[dy] - s1) <= base_type::m_width)
-            {
-                dist_start -= m_di.dx_start();
-                *p1 = 0;
-                if(dist_start <= 0)
-                {   
-                    *p1 = (cover_type)base_type::m_ren.cover(dist);
-                }
-                ++p1;
-                ++dy;
-            }
-
-            dy = 1;
-            dist_start = m_di.dist_start();
-            while((dist = base_type::m_dist[dy] + s1) <= base_type::m_width)
-            {
-                dist_start += m_di.dx_start();
-                *--p0 = 0;
-                if(dist_start <= 0)
-                {   
-                    *p0 = (cover_type)base_type::m_ren.cover(dist);
-                }
-                ++dy;
-            }
-
-            base_type::m_ren.blend_solid_vspan(base_type::m_x, 
-                                               base_type::m_y - dy + 1,
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return ++base_type::m_step < base_type::m_count;
-        }
-
-        //---------------------------------------------------------------------
-        bool step_ver()
-        {
-            int dist_start;
-            int dist;
-            int dx;
-            int s1 = base_type::step_ver_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            dist_start = m_di.dist_start();
-
-            *p1 = 0;
-            if(dist_start <= 0)
-            {
-                *p1 = (cover_type)base_type::m_ren.cover(s1);
-            }
-            ++p1;
-
-            dx = 1;
-            while((dist = base_type::m_dist[dx] - s1) <= base_type::m_width)
-            {
-                dist_start += m_di.dy_start();
-                *p1 = 0;
-                if(dist_start <= 0)
-                {   
-                    *p1 = (cover_type)base_type::m_ren.cover(dist);
-                }
-                ++p1;
-                ++dx;
-            }
-
-            dx = 1;
-            dist_start = m_di.dist_start();
-            while((dist = base_type::m_dist[dx] + s1) <= base_type::m_width)
-            {
-                dist_start -= m_di.dy_start();
-                *--p0 = 0;
-                if(dist_start <= 0)
-                {   
-                    *p0 = (cover_type)base_type::m_ren.cover(dist);
-                }
-                ++dx;
-            }
-            base_type::m_ren.blend_solid_hspan(base_type::m_x - dx + 1, 
-                                               base_type::m_y,
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return ++base_type::m_step < base_type::m_count;
-        }
-
-    private:
-        line_interpolator_aa1(const line_interpolator_aa1<Renderer>&);
-        const line_interpolator_aa1<Renderer>& 
-            operator = (const line_interpolator_aa1<Renderer>&);
-
-        //---------------------------------------------------------------------
-        distance_interpolator2 m_di; 
-    };
-
-
-
-
-
-
-
-
-
-
-
-
-    //====================================================line_interpolator_aa2
-    template<class Renderer> class line_interpolator_aa2 :
-    public line_interpolator_aa_base<Renderer>
-    {
-    public:
-        typedef Renderer renderer_type;
-        typedef typename Renderer::color_type color_type;
-        typedef line_interpolator_aa_base<Renderer> base_type;
-
-        //---------------------------------------------------------------------
-        line_interpolator_aa2(renderer_type& ren, line_parameters& lp, 
-                              int ex, int ey) :
-            line_interpolator_aa_base<Renderer>(ren, lp),
-            m_di(lp.x1, lp.y1, lp.x2, lp.y2, ex, ey, 
-                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask,
-                 0)
-        {
-            base_type::m_li.adjust_forward();
-            base_type::m_step -= base_type::m_max_extent;
-        }
-
-        //---------------------------------------------------------------------
-        bool step_hor()
-        {
-            int dist_end;
-            int dist;
-            int dy;
-            int s1 = base_type::step_hor_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            dist_end = m_di.dist_end();
-
-            int npix = 0;
-            *p1 = 0;
-            if(dist_end > 0)
-            {
-                *p1 = (cover_type)base_type::m_ren.cover(s1);
-                ++npix;
-            }
-            ++p1;
-
-            dy = 1;
-            while((dist = base_type::m_dist[dy] - s1) <= base_type::m_width)
-            {
-                dist_end -= m_di.dx_end();
-                *p1 = 0;
-                if(dist_end > 0)
-                {   
-                    *p1 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++p1;
-                ++dy;
-            }
-
-            dy = 1;
-            dist_end = m_di.dist_end();
-            while((dist = base_type::m_dist[dy] + s1) <= base_type::m_width)
-            {
-                dist_end += m_di.dx_end();
-                *--p0 = 0;
-                if(dist_end > 0)
-                {   
-                    *p0 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++dy;
-            }
-            base_type::m_ren.blend_solid_vspan(base_type::m_x,
-                                               base_type::m_y - dy + 1, 
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return npix && ++base_type::m_step < base_type::m_count;
-        }
-
-        //---------------------------------------------------------------------
-        bool step_ver()
-        {
-            int dist_end;
-            int dist;
-            int dx;
-            int s1 = base_type::step_ver_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            dist_end = m_di.dist_end();
-
-            int npix = 0;
-            *p1 = 0;
-            if(dist_end > 0)
-            {
-                *p1 = (cover_type)base_type::m_ren.cover(s1);
-                ++npix;
-            }
-            ++p1;
-
-            dx = 1;
-            while((dist = base_type::m_dist[dx] - s1) <= base_type::m_width)
-            {
-                dist_end += m_di.dy_end();
-                *p1 = 0;
-                if(dist_end > 0)
-                {   
-                    *p1 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++p1;
-                ++dx;
-            }
-
-            dx = 1;
-            dist_end = m_di.dist_end();
-            while((dist = base_type::m_dist[dx] + s1) <= base_type::m_width)
-            {
-                dist_end -= m_di.dy_end();
-                *--p0 = 0;
-                if(dist_end > 0)
-                {   
-                    *p0 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++dx;
-            }
-            base_type::m_ren.blend_solid_hspan(base_type::m_x - dx + 1,
-                                               base_type::m_y, 
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return npix && ++base_type::m_step < base_type::m_count;
-        }
-
-    private:
-        line_interpolator_aa2(const line_interpolator_aa2<Renderer>&);
-        const line_interpolator_aa2<Renderer>& 
-            operator = (const line_interpolator_aa2<Renderer>&);
-
-        //---------------------------------------------------------------------
-        distance_interpolator2 m_di; 
-    };
-
-
-
-
-
-
-
-
-
-
-    //====================================================line_interpolator_aa3
-    template<class Renderer> class line_interpolator_aa3 :
-    public line_interpolator_aa_base<Renderer>
-    {
-    public:
-        typedef Renderer renderer_type;
-        typedef typename Renderer::color_type color_type;
-        typedef line_interpolator_aa_base<Renderer> base_type;
-
-        //---------------------------------------------------------------------
-        line_interpolator_aa3(renderer_type& ren, line_parameters& lp, 
-                              int sx, int sy, int ex, int ey) :
-            line_interpolator_aa_base<Renderer>(ren, lp),
-            m_di(lp.x1, lp.y1, lp.x2, lp.y2, sx, sy, ex, ey, 
-                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask)
-        {
-            int dist1_start;
-            int dist2_start;
-            int npix = 1;
-            if(lp.vertical)
-            {
-                do
-                {
-                    --base_type::m_li;
-                    base_type::m_y -= lp.inc;
-                    base_type::m_x = (base_type::m_lp->x1 + base_type::m_li.y()) >> line_subpixel_shift;
-
-                    if(lp.inc > 0) m_di.dec_y(base_type::m_x - base_type::m_old_x);
-                    else           m_di.inc_y(base_type::m_x - base_type::m_old_x);
-
-                    base_type::m_old_x = base_type::m_x;
-
-                    dist1_start = dist2_start = m_di.dist_start(); 
-
-                    int dx = 0;
-                    if(dist1_start < 0) ++npix;
-                    do
-                    {
-                        dist1_start += m_di.dy_start();
-                        dist2_start -= m_di.dy_start();
-                        if(dist1_start < 0) ++npix;
-                        if(dist2_start < 0) ++npix;
-                        ++dx;
-                    }
-                    while(base_type::m_dist[dx] <= base_type::m_width);
-                    if(npix == 0) break;
-                    npix = 0;
-                }
-                while(--base_type::m_step >= -base_type::m_max_extent);
-            }
-            else
-            {
-                do
-                {
-                    --base_type::m_li;
-                    base_type::m_x -= lp.inc;
-                    base_type::m_y = (base_type::m_lp->y1 + base_type::m_li.y()) >> line_subpixel_shift;
-
-                    if(lp.inc > 0) m_di.dec_x(base_type::m_y - base_type::m_old_y);
-                    else           m_di.inc_x(base_type::m_y - base_type::m_old_y);
-
-                    base_type::m_old_y = base_type::m_y;
-
-                    dist1_start = dist2_start = m_di.dist_start(); 
-
-                    int dy = 0;
-                    if(dist1_start < 0) ++npix;
-                    do
-                    {
-                        dist1_start -= m_di.dx_start();
-                        dist2_start += m_di.dx_start();
-                        if(dist1_start < 0) ++npix;
-                        if(dist2_start < 0) ++npix;
-                        ++dy;
-                    }
-                    while(base_type::m_dist[dy] <= base_type::m_width);
-                    if(npix == 0) break;
-                    npix = 0;
-                }
-                while(--base_type::m_step >= -base_type::m_max_extent);
-            }
-            base_type::m_li.adjust_forward();
-            base_type::m_step -= base_type::m_max_extent;
-        }
-
-
-        //---------------------------------------------------------------------
-        bool step_hor()
-        {
-            int dist_start;
-            int dist_end;
-            int dist;
-            int dy;
-            int s1 = base_type::step_hor_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            dist_start = m_di.dist_start();
-            dist_end   = m_di.dist_end();
-
-            int npix = 0;
-            *p1 = 0;
-            if(dist_end > 0)
-            {
-                if(dist_start <= 0)
-                {
-                    *p1 = (cover_type)base_type::m_ren.cover(s1);
-                }
-                ++npix;
-            }
-            ++p1;
-
-            dy = 1;
-            while((dist = base_type::m_dist[dy] - s1) <= base_type::m_width)
-            {
-                dist_start -= m_di.dx_start();
-                dist_end   -= m_di.dx_end();
-                *p1 = 0;
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    *p1 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++p1;
-                ++dy;
-            }
-
-            dy = 1;
-            dist_start = m_di.dist_start();
-            dist_end   = m_di.dist_end();
-            while((dist = base_type::m_dist[dy] + s1) <= base_type::m_width)
-            {
-                dist_start += m_di.dx_start();
-                dist_end   += m_di.dx_end();
-                *--p0 = 0;
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    *p0 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++dy;
-            }
-            base_type::m_ren.blend_solid_vspan(base_type::m_x,
-                                               base_type::m_y - dy + 1, 
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return npix && ++base_type::m_step < base_type::m_count;
-        }
-
-        //---------------------------------------------------------------------
-        bool step_ver()
-        {
-            int dist_start;
-            int dist_end;
-            int dist;
-            int dx;
-            int s1 = base_type::step_ver_base(m_di);
-            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
-            cover_type* p1 = p0;
-
-            dist_start = m_di.dist_start();
-            dist_end   = m_di.dist_end();
-
-            int npix = 0;
-            *p1 = 0;
-            if(dist_end > 0)
-            {
-                if(dist_start <= 0)
-                {
-                    *p1 = (cover_type)base_type::m_ren.cover(s1);
-                }
-                ++npix;
-            }
-            ++p1;
-
-            dx = 1;
-            while((dist = base_type::m_dist[dx] - s1) <= base_type::m_width)
-            {
-                dist_start += m_di.dy_start();
-                dist_end   += m_di.dy_end();
-                *p1 = 0;
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    *p1 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++p1;
-                ++dx;
-            }
-
-            dx = 1;
-            dist_start = m_di.dist_start();
-            dist_end   = m_di.dist_end();
-            while((dist = base_type::m_dist[dx] + s1) <= base_type::m_width)
-            {
-                dist_start -= m_di.dy_start();
-                dist_end   -= m_di.dy_end();
-                *--p0 = 0;
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    *p0 = (cover_type)base_type::m_ren.cover(dist);
-                    ++npix;
-                }
-                ++dx;
-            }
-            base_type::m_ren.blend_solid_hspan(base_type::m_x - dx + 1,
-                                               base_type::m_y, 
-                                               unsigned(p1 - p0), 
-                                               p0);
-            return npix && ++base_type::m_step < base_type::m_count;
-        }
-
-    private:
-        line_interpolator_aa3(const line_interpolator_aa3<Renderer>&);
-        const line_interpolator_aa3<Renderer>& 
-            operator = (const line_interpolator_aa3<Renderer>&);
-
-        //---------------------------------------------------------------------
-        distance_interpolator3 m_di; 
-    };
-
-
-
-
-    //==========================================================line_profile_aa
-    //
-    // See Implementation agg_line_profile_aa.cpp 
-    // 
-    class line_profile_aa
-    {
-    public:
-        //---------------------------------------------------------------------
-        typedef int8u value_type;
-        enum subpixel_scale_e
-        {
-            subpixel_shift = line_subpixel_shift,
-            subpixel_scale = 1 << subpixel_shift,
-            subpixel_mask  = subpixel_scale - 1
-        };
-
-        enum aa_scale_e
-        {
-            aa_shift = 8,
-            aa_scale = 1 << aa_shift,
-            aa_mask  = aa_scale - 1
-        };
-        
-        //---------------------------------------------------------------------
-        line_profile_aa() : 
-            m_subpixel_width(0),
-            m_min_width(1.0),
-            m_smoother_width(1.0)
-        {
-            int i;
-            for(i = 0; i < aa_scale; i++) m_gamma[i] = (value_type)i;
-        }
-
-        //---------------------------------------------------------------------
-        template<class GammaF> 
-        line_profile_aa(double w, const GammaF& gamma_function) : 
-            m_subpixel_width(0),
-            m_min_width(1.0),
-            m_smoother_width(1.0)
-        {
-            gamma(gamma_function);
-            width(w);
-        }
-
-        //---------------------------------------------------------------------
-        void min_width(double w) { m_min_width = w; }
-        void smoother_width(double w) { m_smoother_width = w; }
-
-        //---------------------------------------------------------------------
-        template<class GammaF> void gamma(const GammaF& gamma_function)
-        { 
-            int i;
-            for(i = 0; i < aa_scale; i++)
-            {
-                m_gamma[i] = value_type(
-                    uround(gamma_function(double(i) / aa_mask) * aa_mask));
-            }
-        }
-
-        void width(double w);
-
-        unsigned profile_size() const { return m_profile.size(); }
-        int subpixel_width() const { return m_subpixel_width; }
-
-        //---------------------------------------------------------------------
-        double min_width() const { return m_min_width; }
-        double smoother_width() const { return m_smoother_width; }
-
-        //---------------------------------------------------------------------
-        value_type value(int dist) const
-        {
-            return m_profile[dist + subpixel_scale*2];
-        }
-
-    private:
-        line_profile_aa(const line_profile_aa&);
-        const line_profile_aa& operator = (const line_profile_aa&);
-
-        value_type* profile(double w);
-        void set(double center_width, double smoother_width);
-
-        //---------------------------------------------------------------------
-        pod_array<value_type> m_profile;
-        value_type            m_gamma[aa_scale];
-        int                   m_subpixel_width;
-        double                m_min_width;
-        double                m_smoother_width;
-    };
-
-
-    //======================================================renderer_outline_aa
-    template<class BaseRenderer> class renderer_outline_aa
-    {
-    public:
-        //---------------------------------------------------------------------
-        typedef BaseRenderer base_ren_type;
-        typedef renderer_outline_aa<base_ren_type> self_type;
-        typedef typename base_ren_type::color_type color_type;
-
-        //---------------------------------------------------------------------
-        renderer_outline_aa(base_ren_type& ren, line_profile_aa& prof) :
-            m_ren(&ren),
-            m_profile(&prof),
-            m_clip_box(0,0,0,0),
-            m_clipping(false)
-        {}
-        void attach(base_ren_type& ren) { m_ren = &ren; }
-
-        //---------------------------------------------------------------------
-        void color(const color_type& c) { m_color = c; }
-        const color_type& color() const { return m_color; }
-
-        //---------------------------------------------------------------------
-        void profile(line_profile_aa& prof) { m_profile = &prof; }
-        line_profile_aa& profile() const { return *m_profile; }
-
-        //---------------------------------------------------------------------
-        int subpixel_width() const { return m_profile->subpixel_width(); }
-
-        //---------------------------------------------------------------------
-        void reset_clipping() { m_clipping = false; }
-        void clip_box(double x1, double y1, double x2, double y2)
-        {
-            m_clip_box.x1 = line_coord_sat::conv(x1);
-            m_clip_box.y1 = line_coord_sat::conv(y1);
-            m_clip_box.x2 = line_coord_sat::conv(x2);
-            m_clip_box.y2 = line_coord_sat::conv(y2);
-            m_clipping = true;
-        }
-
-        //---------------------------------------------------------------------
-        int cover(int d) const
-        {
-            return m_profile->value(d);
-        }
-
-        //-------------------------------------------------------------------------
-        void blend_solid_hspan(int x, int y, unsigned len, const cover_type* covers)
-        {
-            m_ren->blend_solid_hspan(x, y, len, m_color, covers);
-        }
-
-        //-------------------------------------------------------------------------
-        void blend_solid_vspan(int x, int y, unsigned len, const cover_type* covers)
-        {
-            m_ren->blend_solid_vspan(x, y, len, m_color, covers);
-        }
-
-        //-------------------------------------------------------------------------
-        static bool accurate_join_only() { return false; }
-
-        //-------------------------------------------------------------------------
-        template<class Cmp>
-        void semidot_hline(Cmp cmp,
-                           int xc1, int yc1, int xc2, int yc2, 
-                           int x1,  int y1,  int x2)
-        {
-            cover_type covers[line_interpolator_aa_base<self_type>::max_half_width * 2 + 4];
-            cover_type* p0 = covers;
-            cover_type* p1 = covers;
-            int x = x1 << line_subpixel_shift;
-            int y = y1 << line_subpixel_shift;
-            int w = subpixel_width();
-            distance_interpolator0 di(xc1, yc1, xc2, yc2, x, y);
-            x += line_subpixel_scale/2;
-            y += line_subpixel_scale/2;
-
-            int x0 = x1;
-            int dx = x - xc1;
-            int dy = y - yc1;
-            do
-            {
-                int d = int(fast_sqrt(dx*dx + dy*dy));
-                *p1 = 0;
-                if(cmp(di.dist()) && d <= w)
-                {
-                    *p1 = (cover_type)cover(d);
-                }
-                ++p1;
-                dx += line_subpixel_scale;
-                di.inc_x();
-            }
-            while(++x1 <= x2);
-            m_ren->blend_solid_hspan(x0, y1, 
-                                     unsigned(p1 - p0), 
-                                     color(), 
-                                     p0);
-        }
-
-        //-------------------------------------------------------------------------
-        template<class Cmp> 
-        void semidot(Cmp cmp, int xc1, int yc1, int xc2, int yc2)
-        {
-            if(m_clipping && clipping_flags(xc1, yc1, m_clip_box)) return;
-
-            int r = ((subpixel_width() + line_subpixel_mask) >> line_subpixel_shift);
-            if(r < 1) r = 1;
-            ellipse_bresenham_interpolator ei(r, r);
-            int dx = 0;
-            int dy = -r;
-            int dy0 = dy;
-            int dx0 = dx;
-            int x = xc1 >> line_subpixel_shift;
-            int y = yc1 >> line_subpixel_shift;
-
-            do
-            {
-                dx += ei.dx();
-                dy += ei.dy();
-
-                if(dy != dy0)
-                {
-                    semidot_hline(cmp, xc1, yc1, xc2, yc2, x-dx0, y+dy0, x+dx0);
-                    semidot_hline(cmp, xc1, yc1, xc2, yc2, x-dx0, y-dy0, x+dx0);
-                }
-                dx0 = dx;
-                dy0 = dy;
-                ++ei;
-            }
-            while(dy < 0);
-            semidot_hline(cmp, xc1, yc1, xc2, yc2, x-dx0, y+dy0, x+dx0);
-        }
-
-        //-------------------------------------------------------------------------
-        void pie_hline(int xc, int yc, int xp1, int yp1, int xp2, int yp2, 
-                       int xh1, int yh1, int xh2)
-        {
-            if(m_clipping && clipping_flags(xc, yc, m_clip_box)) return;
-           
-            cover_type covers[line_interpolator_aa_base<self_type>::max_half_width * 2 + 4];
-            cover_type* p0 = covers;
-            cover_type* p1 = covers;
-            int x = xh1 << line_subpixel_shift;
-            int y = yh1 << line_subpixel_shift;
-            int w = subpixel_width();
-
-            distance_interpolator00 di(xc, yc, xp1, yp1, xp2, yp2, x, y);
-            x += line_subpixel_scale/2;
-            y += line_subpixel_scale/2;
-
-            int xh0 = xh1;
-            int dx = x - xc;
-            int dy = y - yc;
-            do
-            {
-                int d = int(fast_sqrt(dx*dx + dy*dy));
-                *p1 = 0;
-                if(di.dist1() <= 0 && di.dist2() > 0 && d <= w)
-                {
-                    *p1 = (cover_type)cover(d);
-                }
-                ++p1;
-                dx += line_subpixel_scale;
-                di.inc_x();
-            }
-            while(++xh1 <= xh2);
-            m_ren->blend_solid_hspan(xh0, yh1, 
-                                     unsigned(p1 - p0), 
-                                     color(), 
-                                     p0);
-        }
-
-
-        //-------------------------------------------------------------------------
-        void pie(int xc, int yc, int x1, int y1, int x2, int y2)
-        {
-            int r = ((subpixel_width() + line_subpixel_mask) >> line_subpixel_shift);
-            if(r < 1) r = 1;
-            ellipse_bresenham_interpolator ei(r, r);
-            int dx = 0;
-            int dy = -r;
-            int dy0 = dy;
-            int dx0 = dx;
-            int x = xc >> line_subpixel_shift;
-            int y = yc >> line_subpixel_shift;
-
-            do
-            {
-                dx += ei.dx();
-                dy += ei.dy();
-
-                if(dy != dy0)
-                {
-                    pie_hline(xc, yc, x1, y1, x2, y2, x-dx0, y+dy0, x+dx0);
-                    pie_hline(xc, yc, x1, y1, x2, y2, x-dx0, y-dy0, x+dx0);
-                }
-                dx0 = dx;
-                dy0 = dy;
-                ++ei;
-            }
-            while(dy < 0);
-            pie_hline(xc, yc, x1, y1, x2, y2, x-dx0, y+dy0, x+dx0);
-        }
-
-        //-------------------------------------------------------------------------
-        void line0_no_clip(line_parameters& lp)
-        {
-            if(lp.len > line_max_length)
-            {
-                line_parameters lp1, lp2;
-                lp.divide(lp1, lp2);
-                line0_no_clip(lp1);
-                line0_no_clip(lp2);
-                return;
-            }
-
-            line_interpolator_aa0<self_type> li(*this, lp);
-            if(li.count())
-            {
-                if(li.vertical())
-                {
-                    while(li.step_ver());
-                }
-                else
-                {
-                    while(li.step_hor());
-                }
-            }
-        }
-
-        //-------------------------------------------------------------------------
-        void line0(line_parameters& lp)
-        {
-            if(m_clipping)
-            {
-                int x1 = lp.x1;
-                int y1 = lp.y1;
-                int x2 = lp.x2;
-                int y2 = lp.y2;
-                unsigned flags = clip_line_segment(&x1, &y1, &x2, &y2, m_clip_box);
-                if((flags & 4) == 0)
-                {
-                    if(flags)
-                    {
-                        line_parameters lp2(x1, y1, x2, y2, 
-                                           uround(calc_distance(x1, y1, x2, y2)));
-                        line0_no_clip(lp2);
-                    }
-                    else
-                    {
-                        line0_no_clip(lp);
-                    }
-                }
-            }
-            else
-            {
-                line0_no_clip(lp);
-            }
-        }
-
-        //-------------------------------------------------------------------------
-        void line1_no_clip(line_parameters& lp, int sx, int sy)
-        {
-            if(lp.len > line_max_length)
-            {
-                line_parameters lp1, lp2;
-                lp.divide(lp1, lp2);
-                line1_no_clip(lp1, (lp.x1 + sx) >> 1, (lp.y1 + sy) >> 1);
-                line1_no_clip(lp2, lp1.x2 + (lp1.y2 - lp1.y1), lp1.y2 - (lp1.x2 - lp1.x1));
-                return;
-            }
-
-            fix_degenerate_bisectrix_start(lp, &sx, &sy);
-            line_interpolator_aa1<self_type> li(*this, lp, sx, sy);
-            if(li.vertical())
-            {
-                while(li.step_ver());
-            }
-            else
-            {
-                while(li.step_hor());
-            }
-        }
-
-
-        //-------------------------------------------------------------------------
-        void line1(line_parameters& lp, int sx, int sy)
-        {
-            if(m_clipping)
-            {
-                int x1 = lp.x1;
-                int y1 = lp.y1;
-                int x2 = lp.x2;
-                int y2 = lp.y2;
-                unsigned flags = clip_line_segment(&x1, &y1, &x2, &y2, m_clip_box);
-                if((flags & 4) == 0)
-                {
-                    if(flags)
-                    {
-                        line_parameters lp2(x1, y1, x2, y2, 
-                                           uround(calc_distance(x1, y1, x2, y2)));
-                        if(flags & 1)
-                        {
-                            sx = x1 + (y2 - y1); 
-                            sy = y1 - (x2 - x1);
-                        }
-                        else
-                        {
-                            while(abs(sx - lp.x1) + abs(sy - lp.y1) > lp2.len)
-                            {
-                                sx = (lp.x1 + sx) >> 1;
-                                sy = (lp.y1 + sy) >> 1;
-                            }
-                        }
-                        line1_no_clip(lp2, sx, sy);
-                    }
-                    else
-                    {
-                        line1_no_clip(lp, sx, sy);
-                    }
-                }
-            }
-            else
-            {
-                line1_no_clip(lp, sx, sy);
-            }
-        }
-
-        //-------------------------------------------------------------------------
-        void line2_no_clip(line_parameters& lp, int ex, int ey)
-        {
-            if(lp.len > line_max_length)
-            {
-                line_parameters lp1, lp2;
-                lp.divide(lp1, lp2);
-                line2_no_clip(lp1, lp1.x2 + (lp1.y2 - lp1.y1), lp1.y2 - (lp1.x2 - lp1.x1));
-                line2_no_clip(lp2, (lp.x2 + ex) >> 1, (lp.y2 + ey) >> 1);
-                return;
-            }
-
-            fix_degenerate_bisectrix_end(lp, &ex, &ey);
-            line_interpolator_aa2<self_type> li(*this, lp, ex, ey);
-            if(li.vertical())
-            {
-                while(li.step_ver());
-            }
-            else
-            {
-                while(li.step_hor());
-            }
-        }
-
-        //-------------------------------------------------------------------------
-        void line2(line_parameters& lp, int ex, int ey)
-        {
-            if(m_clipping)
-            {
-                int x1 = lp.x1;
-                int y1 = lp.y1;
-                int x2 = lp.x2;
-                int y2 = lp.y2;
-                unsigned flags = clip_line_segment(&x1, &y1, &x2, &y2, m_clip_box);
-                if((flags & 4) == 0)
-                {
-                    if(flags)
-                    {
-                        line_parameters lp2(x1, y1, x2, y2, 
-                                           uround(calc_distance(x1, y1, x2, y2)));
-                        if(flags & 2)
-                        {
-                            ex = x2 + (y2 - y1); 
-                            ey = y2 - (x2 - x1);
-                        }
-                        else
-                        {
-                            while(abs(ex - lp.x2) + abs(ey - lp.y2) > lp2.len)
-                            {
-                                ex = (lp.x2 + ex) >> 1;
-                                ey = (lp.y2 + ey) >> 1;
-                            }
-                        }
-                        line2_no_clip(lp2, ex, ey);
-                    }
-                    else
-                    {
-                        line2_no_clip(lp, ex, ey);
-                    }
-                }
-            }
-            else
-            {
-                line2_no_clip(lp, ex, ey);
-            }
-        }
-
-        //-------------------------------------------------------------------------
-        void line3_no_clip(line_parameters& lp, 
-                           int sx, int sy, int ex, int ey)
-        {
-            if(lp.len > line_max_length)
-            {
-                line_parameters lp1, lp2;
-                lp.divide(lp1, lp2);
-                int mx = lp1.x2 + (lp1.y2 - lp1.y1);
-                int my = lp1.y2 - (lp1.x2 - lp1.x1);
-                line3_no_clip(lp1, (lp.x1 + sx) >> 1, (lp.y1 + sy) >> 1, mx, my);
-                line3_no_clip(lp2, mx, my, (lp.x2 + ex) >> 1, (lp.y2 + ey) >> 1);
-                return;
-            }
-
-            fix_degenerate_bisectrix_start(lp, &sx, &sy);
-            fix_degenerate_bisectrix_end(lp, &ex, &ey);
-            line_interpolator_aa3<self_type> li(*this, lp, sx, sy, ex, ey);
-            if(li.vertical())
-            {
-                while(li.step_ver());
-            }
-            else
-            {
-                while(li.step_hor());
-            }
-        }
-
-        //-------------------------------------------------------------------------
-        void line3(line_parameters& lp, 
-                   int sx, int sy, int ex, int ey)
-        {
-            if(m_clipping)
-            {
-                int x1 = lp.x1;
-                int y1 = lp.y1;
-                int x2 = lp.x2;
-                int y2 = lp.y2;
-                unsigned flags = clip_line_segment(&x1, &y1, &x2, &y2, m_clip_box);
-                if((flags & 4) == 0)
-                {
-                    if(flags)
-                    {
-                        line_parameters lp2(x1, y1, x2, y2, 
-                                           uround(calc_distance(x1, y1, x2, y2)));
-                        if(flags & 1)
-                        {
-                            sx = x1 + (y2 - y1); 
-                            sy = y1 - (x2 - x1);
-                        }
-                        else
-                        {
-                            while(abs(sx - lp.x1) + abs(sy - lp.y1) > lp2.len)
-                            {
-                                sx = (lp.x1 + sx) >> 1;
-                                sy = (lp.y1 + sy) >> 1;
-                            }
-                        }
-                        if(flags & 2)
-                        {
-                            ex = x2 + (y2 - y1); 
-                            ey = y2 - (x2 - x1);
-                        }
-                        else
-                        {
-                            while(abs(ex - lp.x2) + abs(ey - lp.y2) > lp2.len)
-                            {
-                                ex = (lp.x2 + ex) >> 1;
-                                ey = (lp.y2 + ey) >> 1;
-                            }
-                        }
-                        line3_no_clip(lp2, sx, sy, ex, ey);
-                    }
-                    else
-                    {
-                        line3_no_clip(lp, sx, sy, ex, ey);
-                    }
-                }
-            }
-            else
-            {
-                line3_no_clip(lp, sx, sy, ex, ey);
-            }
-        }
-
-
-    private:
-        base_ren_type*         m_ren;
-        line_profile_aa* m_profile; 
-        color_type             m_color;
-        rect_i                 m_clip_box;
-        bool                   m_clipping;
-    };
-
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_renderer_outline_image.h b/xs/src/agg/agg_renderer_outline_image.h
deleted file mode 100644
index 2ccc5bedd..000000000
--- a/xs/src/agg/agg_renderer_outline_image.h
+++ /dev/null
@@ -1,1036 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_RENDERER_OUTLINE_IMAGE_INCLUDED
-#define AGG_RENDERER_OUTLINE_IMAGE_INCLUDED
-
-#include "agg_array.h"
-#include "agg_math.h"
-#include "agg_line_aa_basics.h"
-#include "agg_dda_line.h"
-#include "agg_rendering_buffer.h"
-#include "agg_clip_liang_barsky.h"
-
-
-namespace agg
-{
-    //========================================================line_image_scale
-    template<class Source> class line_image_scale
-    {
-    public:
-        typedef typename Source::color_type color_type;
-
-        line_image_scale(const Source& src, double height) :
-            m_source(src), 
-            m_height(height),
-            m_scale(src.height() / height),
-            m_scale_inv(height / src.height())
-        {
-        }
-
-        double width()  const { return m_source.width(); }
-        double height() const { return m_height; }
-
-        color_type pixel(int x, int y) const 
-        { 
-            if (m_scale < 1.0)
-            {
-                // Interpolate between nearest source pixels.
-                double src_y = (y + 0.5) * m_scale - 0.5;
-                int h  = m_source.height() - 1;
-                int y1 = ifloor(src_y);
-                int y2 = y1 + 1;
-                rgba pix1 = (y1 < 0) ? rgba::no_color() : rgba(m_source.pixel(x, y1));
-                rgba pix2 = (y2 > h) ? rgba::no_color() : rgba(m_source.pixel(x, y2));
-                return pix1.gradient(pix2, src_y - y1);
-            }
-            else
-            {
-                // Average source pixels between y and y+1.
-                double src_y1 = (y + 0.5) * m_scale - 0.5;
-                double src_y2 = src_y1 + m_scale;
-                int h  = m_source.height() - 1;
-                int y1 = ifloor(src_y1);
-                int y2 = ifloor(src_y2);
-                rgba c = rgba::no_color();
-                if (y1 >= 0) c += rgba(m_source.pixel(x, y1)) *= y1 + 1 - src_y1;
-                while (++y1 < y2)
-                {
-                    if (y1 <= h) c += m_source.pixel(x, y1);
-                }
-                if (y2 <= h) c += rgba(m_source.pixel(x, y2)) *= src_y2 - y2;
-                return c *= m_scale_inv;
-            }
-        }
-
-    private:
-        line_image_scale(const line_image_scale<Source>&);
-        const line_image_scale<Source>& operator = (const line_image_scale<Source>&);
-
-        const Source& m_source;
-        double        m_height;
-        double        m_scale;
-        double        m_scale_inv;
-    };
-
-
-
-    //======================================================line_image_pattern
-    template<class Filter> class line_image_pattern
-    {
-    public:
-        typedef Filter filter_type;
-        typedef typename filter_type::color_type color_type;
-
-        //--------------------------------------------------------------------
-        line_image_pattern(Filter& filter) :
-            m_filter(&filter),
-            m_dilation(filter.dilation() + 1),
-            m_dilation_hr(m_dilation << line_subpixel_shift),
-            m_data(),
-            m_width(0),
-            m_height(0),
-            m_width_hr(0),
-            m_half_height_hr(0),
-            m_offset_y_hr(0)
-        {
-        }
-
-        // Create
-        //--------------------------------------------------------------------
-        template<class Source> 
-        line_image_pattern(Filter& filter, const Source& src) :
-            m_filter(&filter),
-            m_dilation(filter.dilation() + 1),
-            m_dilation_hr(m_dilation << line_subpixel_shift),
-            m_data(),
-            m_width(0),
-            m_height(0),
-            m_width_hr(0),
-            m_half_height_hr(0),
-            m_offset_y_hr(0)
-        {
-            create(src);
-        }
-
-        // Create
-        //--------------------------------------------------------------------
-        template<class Source> void create(const Source& src)
-        {
-            m_height = uceil(src.height());
-            m_width  = uceil(src.width());
-            m_width_hr = uround(src.width() * line_subpixel_scale);
-            m_half_height_hr = uround(src.height() * line_subpixel_scale/2);
-            m_offset_y_hr = m_dilation_hr + m_half_height_hr - line_subpixel_scale/2;
-            m_half_height_hr += line_subpixel_scale/2;
-
-            m_data.resize((m_width + m_dilation * 2) * (m_height + m_dilation * 2));
-
-            m_buf.attach(&m_data[0], m_width  + m_dilation * 2, 
-                                     m_height + m_dilation * 2, 
-                                     m_width  + m_dilation * 2);
-            unsigned x, y;
-            color_type* d1;
-            color_type* d2;
-            for(y = 0; y < m_height; y++)
-            {
-                d1 = m_buf.row_ptr(y + m_dilation) + m_dilation;
-                for(x = 0; x < m_width; x++)
-                {
-                    *d1++ = src.pixel(x, y);
-                }
-            }
-
-            const color_type* s1;
-            const color_type* s2;
-            for(y = 0; y < m_dilation; y++)
-            {
-                //s1 = m_buf.row_ptr(m_height + m_dilation - 1) + m_dilation;
-                //s2 = m_buf.row_ptr(m_dilation) + m_dilation;
-                d1 = m_buf.row_ptr(m_dilation + m_height + y) + m_dilation;
-                d2 = m_buf.row_ptr(m_dilation - y - 1) + m_dilation;
-                for(x = 0; x < m_width; x++)
-                {
-                    //*d1++ = color_type(*s1++, 0);
-                    //*d2++ = color_type(*s2++, 0);
-                    *d1++ = color_type::no_color();
-                    *d2++ = color_type::no_color();
-                }
-            }
-
-            unsigned h = m_height + m_dilation * 2;
-            for(y = 0; y < h; y++)
-            {
-                s1 = m_buf.row_ptr(y) + m_dilation;
-                s2 = m_buf.row_ptr(y) + m_dilation + m_width;
-                d1 = m_buf.row_ptr(y) + m_dilation + m_width;
-                d2 = m_buf.row_ptr(y) + m_dilation;
-
-                for(x = 0; x < m_dilation; x++)
-                {
-                    *d1++ = *s1++;
-                    *--d2 = *--s2;
-                }
-            }
-        }
-
-        //--------------------------------------------------------------------
-        int pattern_width() const { return m_width_hr; }
-        int line_width()    const { return m_half_height_hr; }
-        double width()      const { return m_height; }
-
-        //--------------------------------------------------------------------
-        void pixel(color_type* p, int x, int y) const
-        {
-            m_filter->pixel_high_res(m_buf.rows(), 
-                                     p, 
-                                     x % m_width_hr + m_dilation_hr,
-                                     y + m_offset_y_hr);
-        }
-
-        //--------------------------------------------------------------------
-        const filter_type& filter() const { return *m_filter; }
-
-    private:
-        line_image_pattern(const line_image_pattern<filter_type>&);
-        const line_image_pattern<filter_type>& 
-            operator = (const line_image_pattern<filter_type>&);
-
-    protected:
-        row_ptr_cache<color_type> m_buf;
-        const filter_type*        m_filter;
-        unsigned                  m_dilation;
-        int                       m_dilation_hr;
-        pod_array<color_type>     m_data;
-        unsigned                  m_width;
-        unsigned                  m_height;
-        int                       m_width_hr;
-        int                       m_half_height_hr;
-        int                       m_offset_y_hr;
-    };
-
-
-
-
-
-
-    //=================================================line_image_pattern_pow2
-    template<class Filter> class line_image_pattern_pow2 : 
-    public line_image_pattern<Filter>
-    {
-    public:
-        typedef Filter filter_type;
-        typedef typename filter_type::color_type color_type;
-        typedef line_image_pattern<Filter> base_type;
-
-        //--------------------------------------------------------------------
-        line_image_pattern_pow2(Filter& filter) :
-            line_image_pattern<Filter>(filter), m_mask(line_subpixel_mask) {}
-
-        //--------------------------------------------------------------------
-        template<class Source> 
-        line_image_pattern_pow2(Filter& filter, const Source& src) :
-            line_image_pattern<Filter>(filter), m_mask(line_subpixel_mask)
-        {
-            create(src);
-        }
-            
-        //--------------------------------------------------------------------
-        template<class Source> void create(const Source& src)
-        {
-            line_image_pattern<Filter>::create(src);
-            m_mask = 1;
-            while(m_mask < base_type::m_width) 
-            {
-                m_mask <<= 1;
-                m_mask |= 1;
-            }
-            m_mask <<= line_subpixel_shift - 1;
-            m_mask |=  line_subpixel_mask;
-            base_type::m_width_hr = m_mask + 1;
-        }
-
-        //--------------------------------------------------------------------
-        void pixel(color_type* p, int x, int y) const
-        {
-            base_type::m_filter->pixel_high_res(
-                    base_type::m_buf.rows(), 
-                    p,
-                    (x & m_mask) + base_type::m_dilation_hr,
-                    y + base_type::m_offset_y_hr);
-        }
-    private:
-        unsigned m_mask;
-    };
-    
-    
-    
-    
-    
-    
-    
-    //===================================================distance_interpolator4
-    class distance_interpolator4
-    {
-    public:
-        //---------------------------------------------------------------------
-        distance_interpolator4() {}
-        distance_interpolator4(int x1,  int y1, int x2, int y2,
-                               int sx,  int sy, int ex, int ey, 
-                               int len, double scale, int x, int y) :
-            m_dx(x2 - x1),
-            m_dy(y2 - y1),
-            m_dx_start(line_mr(sx) - line_mr(x1)),
-            m_dy_start(line_mr(sy) - line_mr(y1)),
-            m_dx_end(line_mr(ex) - line_mr(x2)),
-            m_dy_end(line_mr(ey) - line_mr(y2)),
-
-            m_dist(iround(double(x + line_subpixel_scale/2 - x2) * double(m_dy) - 
-                          double(y + line_subpixel_scale/2 - y2) * double(m_dx))),
-
-            m_dist_start((line_mr(x + line_subpixel_scale/2) - line_mr(sx)) * m_dy_start - 
-                         (line_mr(y + line_subpixel_scale/2) - line_mr(sy)) * m_dx_start),
-
-            m_dist_end((line_mr(x + line_subpixel_scale/2) - line_mr(ex)) * m_dy_end - 
-                       (line_mr(y + line_subpixel_scale/2) - line_mr(ey)) * m_dx_end),
-            m_len(uround(len / scale))
-        {
-            double d = len * scale;
-            int dx = iround(((x2 - x1) << line_subpixel_shift) / d);
-            int dy = iround(((y2 - y1) << line_subpixel_shift) / d);
-            m_dx_pict   = -dy;
-            m_dy_pict   =  dx;
-            m_dist_pict =  ((x + line_subpixel_scale/2 - (x1 - dy)) * m_dy_pict - 
-                            (y + line_subpixel_scale/2 - (y1 + dx)) * m_dx_pict) >> 
-                           line_subpixel_shift;
-
-            m_dx       <<= line_subpixel_shift;
-            m_dy       <<= line_subpixel_shift;
-            m_dx_start <<= line_mr_subpixel_shift;
-            m_dy_start <<= line_mr_subpixel_shift;
-            m_dx_end   <<= line_mr_subpixel_shift;
-            m_dy_end   <<= line_mr_subpixel_shift;
-        }
-
-        //---------------------------------------------------------------------
-        void inc_x() 
-        { 
-            m_dist += m_dy; 
-            m_dist_start += m_dy_start; 
-            m_dist_pict += m_dy_pict; 
-            m_dist_end += m_dy_end; 
-        }
-
-        //---------------------------------------------------------------------
-        void dec_x() 
-        { 
-            m_dist -= m_dy; 
-            m_dist_start -= m_dy_start; 
-            m_dist_pict -= m_dy_pict; 
-            m_dist_end -= m_dy_end; 
-        }
-
-        //---------------------------------------------------------------------
-        void inc_y() 
-        { 
-            m_dist -= m_dx; 
-            m_dist_start -= m_dx_start; 
-            m_dist_pict -= m_dx_pict; 
-            m_dist_end -= m_dx_end; 
-        }
-
-        //---------------------------------------------------------------------
-        void dec_y() 
-        { 
-            m_dist += m_dx; 
-            m_dist_start += m_dx_start; 
-            m_dist_pict += m_dx_pict; 
-            m_dist_end += m_dx_end; 
-        }
-
-        //---------------------------------------------------------------------
-        void inc_x(int dy)
-        {
-            m_dist       += m_dy; 
-            m_dist_start += m_dy_start; 
-            m_dist_pict  += m_dy_pict; 
-            m_dist_end   += m_dy_end;
-            if(dy > 0)
-            {
-                m_dist       -= m_dx; 
-                m_dist_start -= m_dx_start; 
-                m_dist_pict  -= m_dx_pict; 
-                m_dist_end   -= m_dx_end;
-            }
-            if(dy < 0)
-            {
-                m_dist       += m_dx; 
-                m_dist_start += m_dx_start; 
-                m_dist_pict  += m_dx_pict; 
-                m_dist_end   += m_dx_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void dec_x(int dy)
-        {
-            m_dist       -= m_dy; 
-            m_dist_start -= m_dy_start; 
-            m_dist_pict  -= m_dy_pict; 
-            m_dist_end   -= m_dy_end;
-            if(dy > 0)
-            {
-                m_dist       -= m_dx; 
-                m_dist_start -= m_dx_start; 
-                m_dist_pict  -= m_dx_pict; 
-                m_dist_end   -= m_dx_end;
-            }
-            if(dy < 0)
-            {
-                m_dist       += m_dx; 
-                m_dist_start += m_dx_start; 
-                m_dist_pict  += m_dx_pict; 
-                m_dist_end   += m_dx_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void inc_y(int dx)
-        {
-            m_dist       -= m_dx; 
-            m_dist_start -= m_dx_start; 
-            m_dist_pict  -= m_dx_pict; 
-            m_dist_end   -= m_dx_end;
-            if(dx > 0)
-            {
-                m_dist       += m_dy; 
-                m_dist_start += m_dy_start; 
-                m_dist_pict  += m_dy_pict; 
-                m_dist_end   += m_dy_end;
-            }
-            if(dx < 0)
-            {
-                m_dist       -= m_dy; 
-                m_dist_start -= m_dy_start; 
-                m_dist_pict  -= m_dy_pict; 
-                m_dist_end   -= m_dy_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        void dec_y(int dx)
-        {
-            m_dist       += m_dx; 
-            m_dist_start += m_dx_start; 
-            m_dist_pict  += m_dx_pict; 
-            m_dist_end   += m_dx_end;
-            if(dx > 0)
-            {
-                m_dist       += m_dy; 
-                m_dist_start += m_dy_start; 
-                m_dist_pict  += m_dy_pict; 
-                m_dist_end   += m_dy_end;
-            }
-            if(dx < 0)
-            {
-                m_dist       -= m_dy; 
-                m_dist_start -= m_dy_start; 
-                m_dist_pict  -= m_dy_pict; 
-                m_dist_end   -= m_dy_end;
-            }
-        }
-
-        //---------------------------------------------------------------------
-        int dist()       const { return m_dist;       }
-        int dist_start() const { return m_dist_start; }
-        int dist_pict()  const { return m_dist_pict;  }
-        int dist_end()   const { return m_dist_end;   }
-
-        //---------------------------------------------------------------------
-        int dx()       const { return m_dx;       }
-        int dy()       const { return m_dy;       }
-        int dx_start() const { return m_dx_start; }
-        int dy_start() const { return m_dy_start; }
-        int dx_pict()  const { return m_dx_pict;  }
-        int dy_pict()  const { return m_dy_pict;  }
-        int dx_end()   const { return m_dx_end;   }
-        int dy_end()   const { return m_dy_end;   }
-        int len()      const { return m_len;      }
-
-    private:
-        //---------------------------------------------------------------------
-        int m_dx;
-        int m_dy;
-        int m_dx_start;
-        int m_dy_start;
-        int m_dx_pict;
-        int m_dy_pict;
-        int m_dx_end;
-        int m_dy_end;
-
-        int m_dist;
-        int m_dist_start;
-        int m_dist_pict;
-        int m_dist_end;
-        int m_len;
-    };
-
-
-
-
-
-    //==================================================line_interpolator_image
-    template<class Renderer> class line_interpolator_image
-    {
-    public:
-        typedef Renderer renderer_type;
-        typedef typename Renderer::color_type color_type;
-
-        //---------------------------------------------------------------------
-        enum max_half_width_e
-        { 
-            max_half_width = 64
-        };
-
-        //---------------------------------------------------------------------
-        line_interpolator_image(renderer_type& ren, const line_parameters& lp,
-                                int sx, int sy, int ex, int ey, 
-                                int pattern_start,
-                                double scale_x) :
-            m_lp(lp),
-            m_li(lp.vertical ? line_dbl_hr(lp.x2 - lp.x1) :
-                               line_dbl_hr(lp.y2 - lp.y1),
-                 lp.vertical ? abs(lp.y2 - lp.y1) : 
-                               abs(lp.x2 - lp.x1) + 1),
-            m_di(lp.x1, lp.y1, lp.x2, lp.y2, sx, sy, ex, ey, lp.len, scale_x,
-                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask),
-            m_ren(ren),
-            m_x(lp.x1 >> line_subpixel_shift),
-            m_y(lp.y1 >> line_subpixel_shift),
-            m_old_x(m_x),
-            m_old_y(m_y),
-            m_count((lp.vertical ? abs((lp.y2 >> line_subpixel_shift) - m_y) :
-                                   abs((lp.x2 >> line_subpixel_shift) - m_x))),
-            m_width(ren.subpixel_width()),
-            //m_max_extent(m_width >> (line_subpixel_shift - 2)),
-            m_max_extent((m_width + line_subpixel_scale) >> line_subpixel_shift),
-            m_start(pattern_start + (m_max_extent + 2) * ren.pattern_width()),
-            m_step(0)
-        {
-            agg::dda2_line_interpolator li(0, lp.vertical ? 
-                                              (lp.dy << agg::line_subpixel_shift) :
-                                              (lp.dx << agg::line_subpixel_shift),
-                                           lp.len);
-
-            unsigned i;
-            int stop = m_width + line_subpixel_scale * 2;
-            for(i = 0; i < max_half_width; ++i)
-            {
-                m_dist_pos[i] = li.y();
-                if(m_dist_pos[i] >= stop) break;
-                ++li;
-            }
-            m_dist_pos[i] = 0x7FFF0000;
-
-            int dist1_start;
-            int dist2_start;
-            int npix = 1;
-
-            if(lp.vertical)
-            {
-                do
-                {
-                    --m_li;
-                    m_y -= lp.inc;
-                    m_x = (m_lp.x1 + m_li.y()) >> line_subpixel_shift;
-
-                    if(lp.inc > 0) m_di.dec_y(m_x - m_old_x);
-                    else           m_di.inc_y(m_x - m_old_x);
-
-                    m_old_x = m_x;
-
-                    dist1_start = dist2_start = m_di.dist_start(); 
-
-                    int dx = 0;
-                    if(dist1_start < 0) ++npix;
-                    do
-                    {
-                        dist1_start += m_di.dy_start();
-                        dist2_start -= m_di.dy_start();
-                        if(dist1_start < 0) ++npix;
-                        if(dist2_start < 0) ++npix;
-                        ++dx;
-                    }
-                    while(m_dist_pos[dx] <= m_width);
-                    if(npix == 0) break;
-
-                    npix = 0;
-                }
-                while(--m_step >= -m_max_extent);
-            }
-            else
-            {
-                do
-                {
-                    --m_li;
-
-                    m_x -= lp.inc;
-                    m_y = (m_lp.y1 + m_li.y()) >> line_subpixel_shift;
-
-                    if(lp.inc > 0) m_di.dec_x(m_y - m_old_y);
-                    else           m_di.inc_x(m_y - m_old_y);
-
-                    m_old_y = m_y;
-
-                    dist1_start = dist2_start = m_di.dist_start(); 
-
-                    int dy = 0;
-                    if(dist1_start < 0) ++npix;
-                    do
-                    {
-                        dist1_start -= m_di.dx_start();
-                        dist2_start += m_di.dx_start();
-                        if(dist1_start < 0) ++npix;
-                        if(dist2_start < 0) ++npix;
-                        ++dy;
-                    }
-                    while(m_dist_pos[dy] <= m_width);
-                    if(npix == 0) break;
-
-                    npix = 0;
-                }
-                while(--m_step >= -m_max_extent);
-            }
-            m_li.adjust_forward();
-            m_step -= m_max_extent;
-        }
-
-        //---------------------------------------------------------------------
-        bool step_hor()
-        {
-            ++m_li;
-            m_x += m_lp.inc;
-            m_y = (m_lp.y1 + m_li.y()) >> line_subpixel_shift;
-
-            if(m_lp.inc > 0) m_di.inc_x(m_y - m_old_y);
-            else             m_di.dec_x(m_y - m_old_y);
-
-            m_old_y = m_y;
-
-            int s1 = m_di.dist() / m_lp.len;
-            int s2 = -s1;
-
-            if(m_lp.inc < 0) s1 = -s1;
-
-            int dist_start;
-            int dist_pict;
-            int dist_end;
-            int dy;
-            int dist;
-
-            dist_start = m_di.dist_start();
-            dist_pict  = m_di.dist_pict() + m_start;
-            dist_end   = m_di.dist_end();
-            color_type* p0 = m_colors + max_half_width + 2;
-            color_type* p1 = p0;
-
-            int npix = 0;
-            p1->clear();
-            if(dist_end > 0)
-            {
-                if(dist_start <= 0)
-                {
-                    m_ren.pixel(p1, dist_pict, s2);
-                }
-                ++npix;
-            }
-            ++p1;
-
-            dy = 1;
-            while((dist = m_dist_pos[dy]) - s1 <= m_width)
-            {
-                dist_start -= m_di.dx_start();
-                dist_pict  -= m_di.dx_pict();
-                dist_end   -= m_di.dx_end();
-                p1->clear();
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    if(m_lp.inc > 0) dist = -dist;
-                    m_ren.pixel(p1, dist_pict, s2 - dist);
-                    ++npix;
-                }
-                ++p1;
-                ++dy;
-            }
-
-            dy = 1;
-            dist_start = m_di.dist_start();
-            dist_pict  = m_di.dist_pict() + m_start;
-            dist_end   = m_di.dist_end();
-            while((dist = m_dist_pos[dy]) + s1 <= m_width)
-            {
-                dist_start += m_di.dx_start();
-                dist_pict  += m_di.dx_pict();
-                dist_end   += m_di.dx_end();
-                --p0;
-                p0->clear();
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    if(m_lp.inc > 0) dist = -dist;
-                    m_ren.pixel(p0, dist_pict, s2 + dist);
-                    ++npix;
-                }
-                ++dy;
-            }
-            m_ren.blend_color_vspan(m_x, 
-                                    m_y - dy + 1, 
-                                    unsigned(p1 - p0), 
-                                    p0); 
-            return npix && ++m_step < m_count;
-        }
-
-
-
-        //---------------------------------------------------------------------
-        bool step_ver()
-        {
-            ++m_li;
-            m_y += m_lp.inc;
-            m_x = (m_lp.x1 + m_li.y()) >> line_subpixel_shift;
-
-            if(m_lp.inc > 0) m_di.inc_y(m_x - m_old_x);
-            else             m_di.dec_y(m_x - m_old_x);
-
-            m_old_x = m_x;
-
-            int s1 = m_di.dist() / m_lp.len;
-            int s2 = -s1;
-
-            if(m_lp.inc > 0) s1 = -s1;
-
-            int dist_start;
-            int dist_pict;
-            int dist_end;
-            int dist;
-            int dx;
-
-            dist_start = m_di.dist_start();
-            dist_pict  = m_di.dist_pict() + m_start;
-            dist_end   = m_di.dist_end();
-            color_type* p0 = m_colors + max_half_width + 2;
-            color_type* p1 = p0;
-
-            int npix = 0;
-            p1->clear();
-            if(dist_end > 0)
-            {
-                if(dist_start <= 0)
-                {
-                    m_ren.pixel(p1, dist_pict, s2);
-                }
-                ++npix;
-            }
-            ++p1;
-
-            dx = 1;
-            while((dist = m_dist_pos[dx]) - s1 <= m_width)
-            {
-                dist_start += m_di.dy_start();
-                dist_pict  += m_di.dy_pict();
-                dist_end   += m_di.dy_end();
-                p1->clear();
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    if(m_lp.inc > 0) dist = -dist;
-                    m_ren.pixel(p1, dist_pict, s2 + dist);
-                    ++npix;
-                }
-                ++p1;
-                ++dx;
-            }
-
-            dx = 1;
-            dist_start = m_di.dist_start();
-            dist_pict  = m_di.dist_pict() + m_start;
-            dist_end   = m_di.dist_end();
-            while((dist = m_dist_pos[dx]) + s1 <= m_width)
-            {
-                dist_start -= m_di.dy_start();
-                dist_pict  -= m_di.dy_pict();
-                dist_end   -= m_di.dy_end();
-                --p0;
-                p0->clear();
-                if(dist_end > 0 && dist_start <= 0)
-                {   
-                    if(m_lp.inc > 0) dist = -dist;
-                    m_ren.pixel(p0, dist_pict, s2 - dist);
-                    ++npix;
-                }
-                ++dx;
-            }
-            m_ren.blend_color_hspan(m_x - dx + 1, 
-                                    m_y, 
-                                    unsigned(p1 - p0), 
-                                    p0);
-            return npix && ++m_step < m_count;
-        }
-
-
-        //---------------------------------------------------------------------
-        int  pattern_end() const { return m_start + m_di.len(); }
-
-        //---------------------------------------------------------------------
-        bool vertical() const { return m_lp.vertical; }
-        int  width() const { return m_width; }
-        int  count() const { return m_count; }
-
-    private:
-        line_interpolator_image(const line_interpolator_image<Renderer>&);
-        const line_interpolator_image<Renderer>&
-            operator = (const line_interpolator_image<Renderer>&);
-
-    protected:
-        const line_parameters& m_lp;
-        dda2_line_interpolator m_li;
-        distance_interpolator4 m_di; 
-        renderer_type&         m_ren;
-        int m_plen;
-        int m_x;
-        int m_y;
-        int m_old_x;
-        int m_old_y;
-        int m_count;
-        int m_width;
-        int m_max_extent;
-        int m_start;
-        int m_step;
-        int m_dist_pos[max_half_width + 1];
-        color_type m_colors[max_half_width * 2 + 4];
-    };
-
-
-
-
-
-
-
-
-    //===================================================renderer_outline_image
-    template<class BaseRenderer, class ImagePattern> 
-    class renderer_outline_image
-    {
-    public:
-        //---------------------------------------------------------------------
-        typedef BaseRenderer base_ren_type;
-        typedef renderer_outline_image<BaseRenderer, ImagePattern> self_type;
-        typedef typename base_ren_type::color_type color_type;
-        typedef ImagePattern pattern_type;
-
-
-        //---------------------------------------------------------------------
-        renderer_outline_image(base_ren_type& ren, pattern_type& patt) :
-            m_ren(&ren),
-            m_pattern(&patt),
-            m_start(0),
-            m_scale_x(1.0),
-            m_clip_box(0,0,0,0),
-            m_clipping(false)
-        {}
-        void attach(base_ren_type& ren) { m_ren = &ren; }
-
-        //---------------------------------------------------------------------
-        void pattern(pattern_type& p) { m_pattern = &p; }
-        pattern_type& pattern() const { return *m_pattern; }
-
-        //---------------------------------------------------------------------
-        void reset_clipping() { m_clipping = false; }
-        void clip_box(double x1, double y1, double x2, double y2)
-        {
-            m_clip_box.x1 = line_coord_sat::conv(x1);
-            m_clip_box.y1 = line_coord_sat::conv(y1);
-            m_clip_box.x2 = line_coord_sat::conv(x2);
-            m_clip_box.y2 = line_coord_sat::conv(y2);
-            m_clipping = true;
-        }
-
-        //---------------------------------------------------------------------
-        void   scale_x(double s) { m_scale_x = s; }
-        double scale_x() const   { return m_scale_x; }
-
-        //---------------------------------------------------------------------
-        void   start_x(double s) { m_start = iround(s * line_subpixel_scale); }
-        double start_x() const   { return double(m_start) / line_subpixel_scale; }
-
-        //---------------------------------------------------------------------
-        int subpixel_width() const { return m_pattern->line_width(); }
-        int pattern_width() const { return m_pattern->pattern_width(); }
-        double width() const { return double(subpixel_width()) / line_subpixel_scale; }
-
-        //-------------------------------------------------------------------------
-        void pixel(color_type* p, int x, int y) const
-        {
-            m_pattern->pixel(p, x, y);
-        }
-
-        //-------------------------------------------------------------------------
-        void blend_color_hspan(int x, int y, unsigned len, const color_type* colors)
-        {
-            m_ren->blend_color_hspan(x, y, len, colors, 0);
-        }
-
-        //-------------------------------------------------------------------------
-        void blend_color_vspan(int x, int y, unsigned len, const color_type* colors)
-        {
-            m_ren->blend_color_vspan(x, y, len, colors, 0);
-        }
-
-        //-------------------------------------------------------------------------
-        static bool accurate_join_only() { return true; }
-
-        //-------------------------------------------------------------------------
-        template<class Cmp> 
-        void semidot(Cmp, int, int, int, int)
-        {
-        }
-
-        //-------------------------------------------------------------------------
-        void pie(int, int, int, int, int, int)
-        {
-        }
-
-        //-------------------------------------------------------------------------
-        void line0(const line_parameters&)
-        {
-        }
-
-        //-------------------------------------------------------------------------
-        void line1(const line_parameters&, int, int)
-        {
-        }
-
-        //-------------------------------------------------------------------------
-        void line2(const line_parameters&, int, int)
-        {
-        }
-
-        //-------------------------------------------------------------------------
-        void line3_no_clip(const line_parameters& lp, 
-                           int sx, int sy, int ex, int ey)
-        {
-            if(lp.len > line_max_length)
-            {
-                line_parameters lp1, lp2;
-                lp.divide(lp1, lp2);
-                int mx = lp1.x2 + (lp1.y2 - lp1.y1);
-                int my = lp1.y2 - (lp1.x2 - lp1.x1);
-                line3_no_clip(lp1, (lp.x1 + sx) >> 1, (lp.y1 + sy) >> 1, mx, my);
-                line3_no_clip(lp2, mx, my, (lp.x2 + ex) >> 1, (lp.y2 + ey) >> 1);
-                return;
-            }
-            
-            fix_degenerate_bisectrix_start(lp, &sx, &sy);
-            fix_degenerate_bisectrix_end(lp, &ex, &ey);
-            line_interpolator_image<self_type> li(*this, lp, 
-                                                  sx, sy, 
-                                                  ex, ey, 
-                                                  m_start, m_scale_x);
-            if(li.vertical())
-            {
-                while(li.step_ver());
-            }
-            else
-            {
-                while(li.step_hor());
-            }
-            m_start += uround(lp.len / m_scale_x);
-        }
-
-        //-------------------------------------------------------------------------
-        void line3(const line_parameters& lp, 
-                   int sx, int sy, int ex, int ey)
-        {
-            if(m_clipping)
-            {
-                int x1 = lp.x1;
-                int y1 = lp.y1;
-                int x2 = lp.x2;
-                int y2 = lp.y2;
-                unsigned flags = clip_line_segment(&x1, &y1, &x2, &y2, m_clip_box);
-                int start = m_start;
-                if((flags & 4) == 0)
-                {
-                    if(flags)
-                    {
-                        line_parameters lp2(x1, y1, x2, y2, 
-                                           uround(calc_distance(x1, y1, x2, y2)));
-                        if(flags & 1)
-                        {
-                            m_start += uround(calc_distance(lp.x1, lp.y1, x1, y1) / m_scale_x);
-                            sx = x1 + (y2 - y1); 
-                            sy = y1 - (x2 - x1);
-                        }
-                        else
-                        {
-                            while(abs(sx - lp.x1) + abs(sy - lp.y1) > lp2.len)
-                            {
-                                sx = (lp.x1 + sx) >> 1;
-                                sy = (lp.y1 + sy) >> 1;
-                            }
-                        }
-                        if(flags & 2)
-                        {
-                            ex = x2 + (y2 - y1); 
-                            ey = y2 - (x2 - x1);
-                        }
-                        else
-                        {
-                            while(abs(ex - lp.x2) + abs(ey - lp.y2) > lp2.len)
-                            {
-                                ex = (lp.x2 + ex) >> 1;
-                                ey = (lp.y2 + ey) >> 1;
-                            }
-                        }
-                        line3_no_clip(lp2, sx, sy, ex, ey);
-                    }
-                    else
-                    {
-                        line3_no_clip(lp, sx, sy, ex, ey);
-                    }
-                }
-                m_start = start + uround(lp.len / m_scale_x);
-            }
-            else
-            {
-                line3_no_clip(lp, sx, sy, ex, ey);
-            }
-        }
-
-    private:
-        base_ren_type*      m_ren;
-        pattern_type* m_pattern;
-        int                 m_start;
-        double              m_scale_x;
-        rect_i              m_clip_box;
-        bool                m_clipping;
-    };
-
-
-
-
-
-}
-
-
-
-#endif
diff --git a/xs/src/agg/agg_renderer_primitives.h b/xs/src/agg/agg_renderer_primitives.h
deleted file mode 100644
index f008db7c9..000000000
--- a/xs/src/agg/agg_renderer_primitives.h
+++ /dev/null
@@ -1,224 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// class renderer_primitives
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_RENDERER_PRIMITIVES_INCLUDED
-#define AGG_RENDERER_PRIMITIVES_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_renderer_base.h"
-#include "agg_dda_line.h"
-#include "agg_ellipse_bresenham.h"
-
-namespace agg
-{
-    //-----------------------------------------------------renderer_primitives
-    template<class BaseRenderer> class renderer_primitives
-    {
-    public:
-        typedef BaseRenderer base_ren_type;
-        typedef typename base_ren_type::color_type color_type;
-
-        //--------------------------------------------------------------------
-        explicit renderer_primitives(base_ren_type& ren) :
-            m_ren(&ren),
-            m_fill_color(),
-            m_line_color(),
-            m_curr_x(0),
-            m_curr_y(0)
-        {}
-        void attach(base_ren_type& ren) { m_ren = &ren; }
-
-        //--------------------------------------------------------------------
-        static int coord(double c) 
-        { 
-            return iround(c * line_bresenham_interpolator::subpixel_scale); 
-        }
-
-        //--------------------------------------------------------------------
-        void fill_color(const color_type& c) { m_fill_color = c; }
-        void line_color(const color_type& c) { m_line_color = c; }
-        const color_type& fill_color() const { return m_fill_color; }
-        const color_type& line_color() const { return m_line_color; }
-
-        //--------------------------------------------------------------------
-        void rectangle(int x1, int y1, int x2, int y2)
-        {
-            m_ren->blend_hline(x1,   y1,   x2-1, m_line_color, cover_full);
-            m_ren->blend_vline(x2,   y1,   y2-1, m_line_color, cover_full);
-            m_ren->blend_hline(x1+1, y2,   x2,   m_line_color, cover_full);
-            m_ren->blend_vline(x1,   y1+1, y2,   m_line_color, cover_full);
-        }
-
-        //--------------------------------------------------------------------
-        void solid_rectangle(int x1, int y1, int x2, int y2)
-        {
-            m_ren->blend_bar(x1, y1, x2, y2, m_fill_color, cover_full);
-        }
-
-        //--------------------------------------------------------------------
-        void outlined_rectangle(int x1, int y1, int x2, int y2) 
-        {
-            rectangle(x1, y1, x2, y2);
-            m_ren->blend_bar(x1+1, y1+1, x2-1, y2-1, m_fill_color, cover_full);
-        }
-
-        //--------------------------------------------------------------------
-        void ellipse(int x, int y, int rx, int ry)
-        {
-            ellipse_bresenham_interpolator ei(rx, ry);
-            int dx = 0;
-            int dy = -ry;
-            do
-            {
-                dx += ei.dx();
-                dy += ei.dy();
-                m_ren->blend_pixel(x + dx, y + dy, m_line_color, cover_full);
-                m_ren->blend_pixel(x + dx, y - dy, m_line_color, cover_full);
-                m_ren->blend_pixel(x - dx, y - dy, m_line_color, cover_full);
-                m_ren->blend_pixel(x - dx, y + dy, m_line_color, cover_full);
-                ++ei;
-            }
-            while(dy < 0);
-        }
-
-        //--------------------------------------------------------------------
-        void solid_ellipse(int x, int y, int rx, int ry)
-        {
-            ellipse_bresenham_interpolator ei(rx, ry);
-            int dx = 0;
-            int dy = -ry;
-            int dy0 = dy;
-            int dx0 = dx;
-
-            do
-            {
-                dx += ei.dx();
-                dy += ei.dy();
-
-                if(dy != dy0)
-                {
-                    m_ren->blend_hline(x-dx0, y+dy0, x+dx0, m_fill_color, cover_full);
-                    m_ren->blend_hline(x-dx0, y-dy0, x+dx0, m_fill_color, cover_full);
-                }
-                dx0 = dx;
-                dy0 = dy;
-                ++ei;
-            }
-            while(dy < 0);
-            m_ren->blend_hline(x-dx0, y+dy0, x+dx0, m_fill_color, cover_full);
-        }
-
-        //--------------------------------------------------------------------
-        void outlined_ellipse(int x, int y, int rx, int ry)
-        {
-            ellipse_bresenham_interpolator ei(rx, ry);
-            int dx = 0;
-            int dy = -ry;
-
-            do
-            {
-                dx += ei.dx();
-                dy += ei.dy();
-
-                m_ren->blend_pixel(x + dx, y + dy, m_line_color, cover_full);
-                m_ren->blend_pixel(x + dx, y - dy, m_line_color, cover_full);
-                m_ren->blend_pixel(x - dx, y - dy, m_line_color, cover_full);
-                m_ren->blend_pixel(x - dx, y + dy, m_line_color, cover_full);
-
-                if(ei.dy() && dx)
-                {
-                   m_ren->blend_hline(x-dx+1, y+dy, x+dx-1, m_fill_color, cover_full);
-                   m_ren->blend_hline(x-dx+1, y-dy, x+dx-1, m_fill_color, cover_full);
-                }
-                ++ei;
-            }
-            while(dy < 0);
-        }
-
-        //--------------------------------------------------------------------
-        void line(int x1, int y1, int x2, int y2, bool last=false)
-        {
-            line_bresenham_interpolator li(x1, y1, x2, y2);
-
-            unsigned len = li.len();
-            if(len == 0)
-            {
-                if(last)
-                {
-                    m_ren->blend_pixel(li.line_lr(x1), li.line_lr(y1), m_line_color, cover_full);
-                }
-                return;
-            }
-
-            if(last) ++len;
-
-            if(li.is_ver())
-            {
-                do
-                {
-                    m_ren->blend_pixel(li.x2(), li.y1(), m_line_color, cover_full);
-                    li.vstep();
-                }
-                while(--len);
-            }
-            else
-            {
-                do
-                {
-                    m_ren->blend_pixel(li.x1(), li.y2(), m_line_color, cover_full);
-                    li.hstep();
-                }
-                while(--len);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        void move_to(int x, int y)
-        {
-            m_curr_x = x;
-            m_curr_y = y;
-        }
-
-        //--------------------------------------------------------------------
-        void line_to(int x, int y, bool last=false)
-        {
-            line(m_curr_x, m_curr_y, x, y, last);
-            m_curr_x = x;
-            m_curr_y = y;
-        }
-
-        //--------------------------------------------------------------------
-        const base_ren_type& ren() const { return *m_ren; }        
-        base_ren_type& ren() { return *m_ren; }        
-
-        //--------------------------------------------------------------------
-        const rendering_buffer& rbuf() const { return m_ren->rbuf(); }
-        rendering_buffer& rbuf() { return m_ren->rbuf(); }
-
-    private:
-        base_ren_type* m_ren;
-        color_type m_fill_color;
-        color_type m_line_color;
-        int m_curr_x;
-        int m_curr_y;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_renderer_raster_text.h b/xs/src/agg/agg_renderer_raster_text.h
deleted file mode 100644
index 87b43f960..000000000
--- a/xs/src/agg/agg_renderer_raster_text.h
+++ /dev/null
@@ -1,264 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_RENDERER_RASTER_TEXT_INCLUDED
-#define AGG_RENDERER_RASTER_TEXT_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //==============================================renderer_raster_htext_solid
-    template<class BaseRenderer, class GlyphGenerator> 
-    class renderer_raster_htext_solid
-    {
-    public:
-        typedef BaseRenderer ren_type;
-        typedef GlyphGenerator glyph_gen_type;
-        typedef typename glyph_gen_type::glyph_rect glyph_rect;
-        typedef typename ren_type::color_type color_type;
-
-        renderer_raster_htext_solid(ren_type& ren, glyph_gen_type& glyph) :
-            m_ren(&ren),
-            m_glyph(&glyph)
-        {}
-        void attach(ren_type& ren) { m_ren = &ren; }
-
-        //--------------------------------------------------------------------
-        void color(const color_type& c) { m_color = c; }
-        const color_type& color() const { return m_color; }
-
-        //--------------------------------------------------------------------
-        template<class CharT>
-        void render_text(double x, double y, const CharT* str, bool flip=false)
-        {
-            glyph_rect r;
-            while(*str)
-            {
-                m_glyph->prepare(&r, x, y, *str, flip);
-                if(r.x2 >= r.x1)
-                {
-                    int i;
-                    if(flip)
-                    {
-                        for(i = r.y1; i <= r.y2; i++)
-                        {
-                            m_ren->blend_solid_hspan(r.x1, i, (r.x2 - r.x1 + 1),
-                                                     m_color,
-                                                     m_glyph->span(r.y2 - i));
-                        }
-                    }
-                    else
-                    {
-                        for(i = r.y1; i <= r.y2; i++)
-                        {
-                            m_ren->blend_solid_hspan(r.x1, i, (r.x2 - r.x1 + 1),
-                                                     m_color,
-                                                     m_glyph->span(i - r.y1));
-                        }
-                    }
-                }
-                x += r.dx;
-                y += r.dy;
-                ++str;
-            }
-        }
-
-    private:
-        ren_type* m_ren;
-        glyph_gen_type* m_glyph;
-        color_type m_color;
-    };
-
-
-
-    //=============================================renderer_raster_vtext_solid
-    template<class BaseRenderer, class GlyphGenerator> 
-    class renderer_raster_vtext_solid
-    {
-    public:
-        typedef BaseRenderer ren_type;
-        typedef GlyphGenerator glyph_gen_type;
-        typedef typename glyph_gen_type::glyph_rect glyph_rect;
-        typedef typename ren_type::color_type color_type;
-
-        renderer_raster_vtext_solid(ren_type& ren, glyph_gen_type& glyph) :
-            m_ren(&ren),
-            m_glyph(&glyph)
-        {
-        }
-
-        //--------------------------------------------------------------------
-        void color(const color_type& c) { m_color = c; }
-        const color_type& color() const { return m_color; }
-
-        //--------------------------------------------------------------------
-        template<class CharT>
-        void render_text(double x, double y, const CharT* str, bool flip=false)
-        {
-            glyph_rect r;
-            while(*str)
-            {
-                m_glyph->prepare(&r, x, y, *str, !flip);
-                if(r.x2 >= r.x1)
-                {
-                    int i;
-                    if(flip)
-                    {
-                        for(i = r.y1; i <= r.y2; i++)
-                        {
-                            m_ren->blend_solid_vspan(i, r.x1, (r.x2 - r.x1 + 1),
-                                                     m_color,
-                                                     m_glyph->span(i - r.y1));
-                        }
-                    }
-                    else
-                    {
-                        for(i = r.y1; i <= r.y2; i++)
-                        {
-                            m_ren->blend_solid_vspan(i, r.x1, (r.x2 - r.x1 + 1),
-                                                     m_color,
-                                                     m_glyph->span(r.y2 - i));
-                        }
-                    }
-                }
-                x += r.dx;
-                y += r.dy;
-                ++str;
-            }
-        }
-
-    private:
-        ren_type* m_ren;
-        glyph_gen_type* m_glyph;
-        color_type m_color;
-    };
-
-
-
-
-
-
-    //===================================================renderer_raster_htext
-    template<class ScanlineRenderer, class GlyphGenerator> 
-    class renderer_raster_htext
-    {
-    public:
-        typedef ScanlineRenderer ren_type;
-        typedef GlyphGenerator glyph_gen_type;
-        typedef typename glyph_gen_type::glyph_rect glyph_rect;
-
-        class scanline_single_span
-        {
-        public:
-            typedef agg::cover_type cover_type;
-
-            //----------------------------------------------------------------
-            struct const_span
-            {
-                int x;
-                unsigned len;
-                const cover_type* covers;
-
-                const_span() {}
-                const_span(int x_, unsigned len_, const cover_type* covers_) :
-                    x(x_), len(len_), covers(covers_) 
-                {}
-            };
-
-            typedef const const_span* const_iterator;
-
-            //----------------------------------------------------------------
-            scanline_single_span(int x, int y, unsigned len, 
-                                 const cover_type* covers) :
-                m_y(y),
-                m_span(x, len, covers)
-            {}
-
-            //----------------------------------------------------------------
-            int      y()           const { return m_y; }
-            unsigned num_spans()   const { return 1;   }
-            const_iterator begin() const { return &m_span; }
-
-        private:
-            //----------------------------------------------------------------
-            int m_y;
-            const_span m_span;
-        };
-
-
-
-        //--------------------------------------------------------------------
-        renderer_raster_htext(ren_type& ren, glyph_gen_type& glyph) :
-            m_ren(&ren),
-            m_glyph(&glyph)
-        {
-        }
-
-
-        //--------------------------------------------------------------------
-        template<class CharT>
-        void render_text(double x, double y, const CharT* str, bool flip=false)
-        {
-            glyph_rect r;
-            while(*str)
-            {
-                m_glyph->prepare(&r, x, y, *str, flip);
-                if(r.x2 >= r.x1)
-                {
-                    m_ren->prepare();
-                    int i;
-                    if(flip)
-                    {
-                        for(i = r.y1; i <= r.y2; i++)
-                        {
-                            m_ren->render(
-                                scanline_single_span(r.x1, 
-                                                     i, 
-                                                     (r.x2 - r.x1 + 1),
-                                                     m_glyph->span(r.y2 - i)));
-                        }
-                    }
-                    else
-                    {
-                        for(i = r.y1; i <= r.y2; i++)
-                        {
-                            m_ren->render(
-                                scanline_single_span(r.x1, 
-                                                     i, 
-                                                     (r.x2 - r.x1 + 1),
-                                                     m_glyph->span(i - r.y1)));
-                        }
-                    }
-                }
-                x += r.dx;
-                y += r.dy;
-                ++str;
-            }
-        }
-
-    private:
-        ren_type* m_ren;
-        glyph_gen_type* m_glyph;
-    };
-
-
-
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_rendering_buffer_dynarow.h b/xs/src/agg/agg_rendering_buffer_dynarow.h
deleted file mode 100644
index 188746f3d..000000000
--- a/xs/src/agg/agg_rendering_buffer_dynarow.h
+++ /dev/null
@@ -1,137 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// class rendering_buffer_dynarow
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_RENDERING_BUFFER_DYNAROW_INCLUDED
-#define AGG_RENDERING_BUFFER_DYNAROW_INCLUDED
-
-#include "agg_array.h"
-
-namespace agg
-{
-
-    //===============================================rendering_buffer_dynarow
-    // Rendering buffer class with dynamic allocation of the rows.
-    // The rows are allocated as needed when requesting for span_ptr().
-    // The class automatically calculates min_x and max_x for each row.
-    // Generally it's more efficient to use this class as a temporary buffer
-    // for rendering a few lines and then to blend it with another buffer.
-    //
-    class rendering_buffer_dynarow
-    {
-    public:
-        typedef row_info<int8u> row_data;
-
-        //-------------------------------------------------------------------
-        ~rendering_buffer_dynarow()
-        {
-            init(0,0,0);
-        }
-
-        //-------------------------------------------------------------------
-        rendering_buffer_dynarow() :
-            m_rows(),
-            m_width(0),
-            m_height(0),
-            m_byte_width(0)
-        {
-        }
-
-        // Allocate and clear the buffer
-        //--------------------------------------------------------------------
-        rendering_buffer_dynarow(unsigned width, unsigned height, 
-                                 unsigned byte_width) :
-            m_rows(height),
-            m_width(width),
-            m_height(height),
-            m_byte_width(byte_width)
-        {
-            memset(&m_rows[0], 0, sizeof(row_data) * height);
-        }
-
-        // Allocate and clear the buffer
-        //--------------------------------------------------------------------
-        void init(unsigned width, unsigned height, unsigned byte_width)
-        {
-            unsigned i;
-            for(i = 0; i < m_height; ++i) 
-            {
-                pod_allocator<int8u>::deallocate((int8u*)m_rows[i].ptr, m_byte_width);
-            }
-            if(width && height)
-            {
-                m_width  = width;
-                m_height = height;
-                m_byte_width = byte_width;
-                m_rows.resize(height);
-                memset(&m_rows[0], 0, sizeof(row_data) * height);
-            }
-        }
-
-        //--------------------------------------------------------------------
-        unsigned width()      const { return m_width;  }
-        unsigned height()     const { return m_height; }
-        unsigned byte_width() const { return m_byte_width; }
-
-        // The main function used for rendering. Returns pointer to the 
-        // pre-allocated span. Memory for the row is allocated as needed.
-        //--------------------------------------------------------------------
-        int8u* row_ptr(int x, int y, unsigned len)
-        {
-            row_data* r = &m_rows[y];
-            int x2 = x + len - 1;
-            if(r->ptr)
-            {
-                if(x  < r->x1) { r->x1 = x;  }
-                if(x2 > r->x2) { r->x2 = x2; }
-            }
-            else
-            {
-                int8u* p = pod_allocator<int8u>::allocate(m_byte_width);
-                r->ptr = p;
-                r->x1  = x;
-                r->x2  = x2;
-                memset(p, 0, m_byte_width);
-            }
-            return (int8u*)r->ptr;
-        }
-
-        //--------------------------------------------------------------------
-        const int8u* row_ptr(int y) const { return m_rows[y].ptr; }
-              int8u* row_ptr(int y)       { return row_ptr(0, y, m_width); }
-        row_data     row    (int y) const { return m_rows[y]; }
-
-    private:
-        //--------------------------------------------------------------------
-        // Prohibit copying
-        rendering_buffer_dynarow(const rendering_buffer_dynarow&);
-        const rendering_buffer_dynarow& operator = (const rendering_buffer_dynarow&);
-
-    private:
-        //--------------------------------------------------------------------
-        pod_array<row_data> m_rows;       // Pointers to each row of the buffer
-        unsigned            m_width;      // Width in pixels
-        unsigned            m_height;     // Height in pixels
-        unsigned            m_byte_width; // Width in bytes
-    };
-
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_rounded_rect.h b/xs/src/agg/agg_rounded_rect.h
deleted file mode 100644
index fe8d26f71..000000000
--- a/xs/src/agg/agg_rounded_rect.h
+++ /dev/null
@@ -1,72 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Rounded rectangle vertex generator
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_ROUNDED_RECT_INCLUDED
-#define AGG_ROUNDED_RECT_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_arc.h"
-
-namespace agg
-{
-    //------------------------------------------------------------rounded_rect
-    //
-    // See Implemantation agg_rounded_rect.cpp
-    //
-    class rounded_rect
-    {
-    public:
-        rounded_rect() {}
-        rounded_rect(double x1, double y1, double x2, double y2, double r);
-
-        void rect(double x1, double y1, double x2, double y2);
-        void radius(double r);
-        void radius(double rx, double ry);
-        void radius(double rx_bottom, double ry_bottom, double rx_top, double ry_top);
-        void radius(double rx1, double ry1, double rx2, double ry2, 
-                    double rx3, double ry3, double rx4, double ry4);
-        void normalize_radius();
-
-        void approximation_scale(double s) { m_arc.approximation_scale(s); }
-        double approximation_scale() const { return m_arc.approximation_scale(); }
-
-        void rewind(unsigned);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        double m_x1;
-        double m_y1;
-        double m_x2;
-        double m_y2;
-        double m_rx1;
-        double m_ry1;
-        double m_rx2;
-        double m_ry2;
-        double m_rx3;
-        double m_ry3;
-        double m_rx4;
-        double m_ry4;
-        unsigned m_status;
-        arc      m_arc;
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_scanline_bin.h b/xs/src/agg/agg_scanline_bin.h
deleted file mode 100644
index 6f9f41e8e..000000000
--- a/xs/src/agg/agg_scanline_bin.h
+++ /dev/null
@@ -1,264 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Class scanline_bin - binary scanline.
-//
-//----------------------------------------------------------------------------
-//
-// Adaptation for 32-bit screen coordinates (scanline32_bin) has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SCANLINE_BIN_INCLUDED
-#define AGG_SCANLINE_BIN_INCLUDED
-
-#include "agg_array.h"
-
-namespace agg
-{
-
-    //=============================================================scanline_bin
-    // 
-    // This is binary scaline container which supports the interface 
-    // used in the rasterizer::render(). See description of agg_scanline_u8 
-    // for details.
-    // 
-    //------------------------------------------------------------------------
-    class scanline_bin
-    {
-    public:
-        typedef int32 coord_type;
-
-        struct span
-        {
-            int16 x;
-            int16 len;
-        };
-
-        typedef const span* const_iterator;
-
-        //--------------------------------------------------------------------
-        scanline_bin() :
-            m_last_x(0x7FFFFFF0),
-            m_spans(),
-            m_cur_span(0)
-        {
-        }
-
-        //--------------------------------------------------------------------
-        void reset(int min_x, int max_x)
-        {
-            unsigned max_len = max_x - min_x + 3;
-            if(max_len > m_spans.size())
-            {
-                m_spans.resize(max_len);
-            }
-            m_last_x   = 0x7FFFFFF0;
-            m_cur_span = &m_spans[0];
-        }
-
-        //--------------------------------------------------------------------
-        void add_cell(int x, unsigned)
-        {
-            if(x == m_last_x+1)
-            {
-                m_cur_span->len++;
-            }
-            else
-            {
-                ++m_cur_span;
-                m_cur_span->x = (int16)x;
-                m_cur_span->len = 1;
-            }
-            m_last_x = x;
-        }
-
-        //--------------------------------------------------------------------
-        void add_span(int x, unsigned len, unsigned)
-        {
-            if(x == m_last_x+1)
-            {
-                m_cur_span->len = (int16)(m_cur_span->len + len);
-            }
-            else
-            {
-                ++m_cur_span;
-                m_cur_span->x = (int16)x;
-                m_cur_span->len = (int16)len;
-            }
-            m_last_x = x + len - 1;
-        }
-
-        //--------------------------------------------------------------------
-        void add_cells(int x, unsigned len, const void*)
-        {
-            add_span(x, len, 0);
-        }
-
-        //--------------------------------------------------------------------
-        void finalize(int y) 
-        { 
-            m_y = y; 
-        }
-
-        //--------------------------------------------------------------------
-        void reset_spans()
-        {
-            m_last_x    = 0x7FFFFFF0;
-            m_cur_span  = &m_spans[0];
-        }
-
-        //--------------------------------------------------------------------
-        int            y()         const { return m_y; }
-        unsigned       num_spans() const { return unsigned(m_cur_span - &m_spans[0]); }
-        const_iterator begin()     const { return &m_spans[1]; }
-
-    private:
-        scanline_bin(const scanline_bin&);
-        const scanline_bin operator = (const scanline_bin&);
-
-        int             m_last_x;
-        int             m_y;
-        pod_array<span> m_spans;
-        span*           m_cur_span;
-    };
-
-
-
-
-
-
-    //===========================================================scanline32_bin
-    class scanline32_bin
-    {
-    public:
-        typedef int32 coord_type;
-
-        //--------------------------------------------------------------------
-        struct span
-        {
-            span() {}
-            span(coord_type x_, coord_type len_) : x(x_), len(len_) {}
-
-            coord_type x;
-            coord_type len;
-        };
-        typedef pod_bvector<span, 4> span_array_type;
-
-
-        //--------------------------------------------------------------------
-        class const_iterator
-        {
-        public:
-            const_iterator(const span_array_type& spans) :
-                m_spans(spans),
-                m_span_idx(0)
-            {}
-
-            const span& operator*()  const { return m_spans[m_span_idx];  }
-            const span* operator->() const { return &m_spans[m_span_idx]; }
-
-            void operator ++ () { ++m_span_idx; }
-
-        private:
-            const span_array_type& m_spans;
-            unsigned               m_span_idx;
-        };
-
-
-        //--------------------------------------------------------------------
-        scanline32_bin() : m_max_len(0), m_last_x(0x7FFFFFF0) {}
-
-        //--------------------------------------------------------------------
-        void reset(int, int)
-        {
-            m_last_x = 0x7FFFFFF0;
-            m_spans.remove_all();
-        }
-
-        //--------------------------------------------------------------------
-        void add_cell(int x, unsigned)
-        {
-            if(x == m_last_x+1)
-            {
-                m_spans.last().len++;
-            }
-            else
-            {
-                m_spans.add(span(coord_type(x), 1));
-            }
-            m_last_x = x;
-        }
-
-        //--------------------------------------------------------------------
-        void add_span(int x, unsigned len, unsigned)
-        {
-            if(x == m_last_x+1)
-            {
-                m_spans.last().len += coord_type(len);
-            }
-            else
-            {
-                m_spans.add(span(coord_type(x), coord_type(len)));
-            }
-            m_last_x = x + len - 1;
-        }
-
-        //--------------------------------------------------------------------
-        void add_cells(int x, unsigned len, const void*)
-        {
-            add_span(x, len, 0);
-        }
-
-        //--------------------------------------------------------------------
-        void finalize(int y) 
-        { 
-            m_y = y; 
-        }
-
-        //--------------------------------------------------------------------
-        void reset_spans()
-        {
-            m_last_x = 0x7FFFFFF0;
-            m_spans.remove_all();
-        }
-
-        //--------------------------------------------------------------------
-        int            y()         const { return m_y; }
-        unsigned       num_spans() const { return m_spans.size(); }
-        const_iterator begin()     const { return const_iterator(m_spans); }
-
-    private:
-        scanline32_bin(const scanline32_bin&);
-        const scanline32_bin operator = (const scanline32_bin&);
-
-        unsigned        m_max_len;
-        int             m_last_x;
-        int             m_y;
-        span_array_type m_spans;
-    };
-
-
-
-
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_scanline_boolean_algebra.h b/xs/src/agg/agg_scanline_boolean_algebra.h
deleted file mode 100644
index bc2e9c9d5..000000000
--- a/xs/src/agg/agg_scanline_boolean_algebra.h
+++ /dev/null
@@ -1,1567 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SCANLINE_BOOLEAN_ALGEBRA_INCLUDED
-#define AGG_SCANLINE_BOOLEAN_ALGEBRA_INCLUDED
-
-#include <stdlib.h>
-#include <math.h>
-#include "agg_basics.h"
-
-
-namespace agg
-{
-
-    //-----------------------------------------------sbool_combine_spans_bin
-    // Functor.
-    // Combine two binary encoded spans, i.e., when we don't have any
-    // anti-aliasing information, but only X and Length. The function
-    // is compatible with any type of scanlines.
-    //----------------
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline> 
-    struct sbool_combine_spans_bin
-    {
-        void operator () (const typename Scanline1::const_iterator&, 
-                          const typename Scanline2::const_iterator&, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            sl.add_span(x, len, cover_full);
-        }
-    };
-
-
-
-    //---------------------------------------------sbool_combine_spans_empty
-    // Functor.
-    // Combine two spans as empty ones. The functor does nothing
-    // and is used to XOR binary spans.
-    //----------------
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline> 
-    struct sbool_combine_spans_empty
-    {
-        void operator () (const typename Scanline1::const_iterator&, 
-                          const typename Scanline2::const_iterator&, 
-                          int, unsigned, 
-                          Scanline&) const
-        {}
-    };
-
-
-
-    //--------------------------------------------------sbool_add_span_empty
-    // Functor.
-    // Add nothing. Used in conbine_shapes_sub
-    //----------------
-    template<class Scanline1, 
-             class Scanline> 
-    struct sbool_add_span_empty
-    {
-        void operator () (const typename Scanline1::const_iterator&, 
-                          int, unsigned, 
-                          Scanline&) const
-        {}
-    };
-
-
-    //----------------------------------------------------sbool_add_span_bin
-    // Functor.
-    // Add a binary span
-    //----------------
-    template<class Scanline1, 
-             class Scanline> 
-    struct sbool_add_span_bin
-    {
-        void operator () (const typename Scanline1::const_iterator&, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            sl.add_span(x, len, cover_full);
-        }
-    };
-
-    
-
-
-    //-----------------------------------------------------sbool_add_span_aa
-    // Functor.
-    // Add an anti-aliased span
-    // anti-aliasing information, but only X and Length. The function
-    // is compatible with any type of scanlines.
-    //----------------
-    template<class Scanline1, 
-             class Scanline> 
-    struct sbool_add_span_aa
-    {
-        void operator () (const typename Scanline1::const_iterator& span, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            if(span->len < 0)
-            {
-                sl.add_span(x, len, *span->covers);
-            }
-            else
-            if(span->len > 0)
-            {
-                const typename Scanline1::cover_type* covers = span->covers;
-                if(span->x < x) covers += x - span->x;
-                sl.add_cells(x, len, covers);
-            }
-        }
-    };
-
-
-
-
-    //----------------------------------------------sbool_intersect_spans_aa
-    // Functor.
-    // Intersect two spans preserving the anti-aliasing information.
-    // The result is added to the "sl" scanline.
-    //------------------
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             unsigned CoverShift = cover_shift> 
-    struct sbool_intersect_spans_aa
-    {
-        enum cover_scale_e
-        {
-            cover_shift = CoverShift,
-            cover_size  = 1 << cover_shift,
-            cover_mask  = cover_size - 1,
-            cover_full  = cover_mask
-        };
-        
-
-        void operator () (const typename Scanline1::const_iterator& span1, 
-                          const typename Scanline2::const_iterator& span2, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            unsigned cover;
-            const typename Scanline1::cover_type* covers1;
-            const typename Scanline2::cover_type* covers2;
-
-            // Calculate the operation code and choose the 
-            // proper combination algorithm.
-            // 0 = Both spans are of AA type
-            // 1 = span1 is solid, span2 is AA
-            // 2 = span1 is AA, span2 is solid
-            // 3 = Both spans are of solid type
-            //-----------------
-            switch((span1->len < 0) | ((span2->len < 0) << 1))
-            {
-            case 0:      // Both are AA spans
-                covers1 = span1->covers;
-                covers2 = span2->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(span2->x < x) covers2 += x - span2->x;
-                do
-                {
-                    cover = *covers1++ * *covers2++;
-                    sl.add_cell(x++, 
-                                (cover == cover_full * cover_full) ?
-                                cover_full : 
-                                (cover >> cover_shift));
-                }
-                while(--len);
-                break;
-
-            case 1:      // span1 is solid, span2 is AA
-                covers2 = span2->covers;
-                if(span2->x < x) covers2 += x - span2->x;
-                if(*(span1->covers) == cover_full)
-                {
-                    sl.add_cells(x, len, covers2);
-                }
-                else
-                {
-                    do
-                    {
-                        cover = *(span1->covers) * *covers2++;
-                        sl.add_cell(x++, 
-                                    (cover == cover_full * cover_full) ?
-                                    cover_full : 
-                                    (cover >> cover_shift));
-                    }
-                    while(--len);
-                }
-                break;
-
-            case 2:      // span1 is AA, span2 is solid
-                covers1 = span1->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(*(span2->covers) == cover_full)
-                {
-                    sl.add_cells(x, len, covers1);
-                }
-                else
-                {
-                    do
-                    {
-                        cover = *covers1++ * *(span2->covers);
-                        sl.add_cell(x++, 
-                                    (cover == cover_full * cover_full) ?
-                                    cover_full : 
-                                    (cover >> cover_shift));
-                    }
-                    while(--len);
-                }
-                break;
-
-            case 3:      // Both are solid spans
-                cover = *(span1->covers) * *(span2->covers);
-                sl.add_span(x, len, 
-                            (cover == cover_full * cover_full) ?
-                            cover_full : 
-                            (cover >> cover_shift));
-                break;
-            }
-        }
-    };
-
-
-
-
-
-
-    //--------------------------------------------------sbool_unite_spans_aa
-    // Functor.
-    // Unite two spans preserving the anti-aliasing information.
-    // The result is added to the "sl" scanline.
-    //------------------
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             unsigned CoverShift = cover_shift> 
-    struct sbool_unite_spans_aa
-    {
-        enum cover_scale_e
-        {
-            cover_shift = CoverShift,
-            cover_size  = 1 << cover_shift,
-            cover_mask  = cover_size - 1,
-            cover_full  = cover_mask
-        };
-        
-
-        void operator () (const typename Scanline1::const_iterator& span1, 
-                          const typename Scanline2::const_iterator& span2, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            unsigned cover;
-            const typename Scanline1::cover_type* covers1;
-            const typename Scanline2::cover_type* covers2;
-
-            // Calculate the operation code and choose the 
-            // proper combination algorithm.
-            // 0 = Both spans are of AA type
-            // 1 = span1 is solid, span2 is AA
-            // 2 = span1 is AA, span2 is solid
-            // 3 = Both spans are of solid type
-            //-----------------
-            switch((span1->len < 0) | ((span2->len < 0) << 1))
-            {
-            case 0:      // Both are AA spans
-                covers1 = span1->covers;
-                covers2 = span2->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(span2->x < x) covers2 += x - span2->x;
-                do
-                {
-                    cover = cover_mask * cover_mask - 
-                                (cover_mask - *covers1++) * 
-                                (cover_mask - *covers2++);
-                    sl.add_cell(x++, 
-                                (cover == cover_full * cover_full) ?
-                                cover_full : 
-                                (cover >> cover_shift));
-                }
-                while(--len);
-                break;
-
-            case 1:      // span1 is solid, span2 is AA
-                covers2 = span2->covers;
-                if(span2->x < x) covers2 += x - span2->x;
-                if(*(span1->covers) == cover_full)
-                {
-                    sl.add_span(x, len, cover_full);
-                }
-                else
-                {
-                    do
-                    {
-                        cover = cover_mask * cover_mask - 
-                                    (cover_mask - *(span1->covers)) * 
-                                    (cover_mask - *covers2++);
-                        sl.add_cell(x++, 
-                                    (cover == cover_full * cover_full) ?
-                                    cover_full : 
-                                    (cover >> cover_shift));
-                    }
-                    while(--len);
-                }
-                break;
-
-            case 2:      // span1 is AA, span2 is solid
-                covers1 = span1->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(*(span2->covers) == cover_full)
-                {
-                    sl.add_span(x, len, cover_full);
-                }
-                else
-                {
-                    do
-                    {
-                        cover = cover_mask * cover_mask - 
-                                    (cover_mask - *covers1++) * 
-                                    (cover_mask - *(span2->covers));
-                        sl.add_cell(x++, 
-                                    (cover == cover_full * cover_full) ?
-                                    cover_full : 
-                                    (cover >> cover_shift));
-                    }
-                    while(--len);
-                }
-                break;
-
-            case 3:      // Both are solid spans
-                cover = cover_mask * cover_mask - 
-                            (cover_mask - *(span1->covers)) * 
-                            (cover_mask - *(span2->covers));
-                sl.add_span(x, len, 
-                            (cover == cover_full * cover_full) ?
-                            cover_full : 
-                            (cover >> cover_shift));
-                break;
-            }
-        }
-    };
-
-
-    //---------------------------------------------sbool_xor_formula_linear
-    template<unsigned CoverShift = cover_shift> 
-    struct sbool_xor_formula_linear
-    {
-        enum cover_scale_e
-        {
-            cover_shift = CoverShift,
-            cover_size  = 1 << cover_shift,
-            cover_mask  = cover_size - 1
-        };
-
-        static AGG_INLINE unsigned calculate(unsigned a, unsigned b)
-        {
-            unsigned cover = a + b;
-            if(cover > cover_mask) cover = cover_mask + cover_mask - cover;
-            return cover;
-        }
-    };
-
-
-    //---------------------------------------------sbool_xor_formula_saddle
-    template<unsigned CoverShift = cover_shift> 
-    struct sbool_xor_formula_saddle
-    {
-        enum cover_scale_e
-        {
-            cover_shift = CoverShift,
-            cover_size  = 1 << cover_shift,
-            cover_mask  = cover_size - 1
-        };
-
-        static AGG_INLINE unsigned calculate(unsigned a, unsigned b)
-        {
-            unsigned k = a * b;
-            if(k == cover_mask * cover_mask) return 0;
-
-            a = (cover_mask * cover_mask - (a << cover_shift) + k) >> cover_shift;
-            b = (cover_mask * cover_mask - (b << cover_shift) + k) >> cover_shift;
-            return cover_mask - ((a * b) >> cover_shift);
-        }
-    };
-
-
-    //-------------------------------------------sbool_xor_formula_abs_diff
-    struct sbool_xor_formula_abs_diff
-    {
-        static AGG_INLINE unsigned calculate(unsigned a, unsigned b)
-        {
-            return unsigned(abs(int(a) - int(b)));
-        }
-    };
-
-
-
-    //----------------------------------------------------sbool_xor_spans_aa
-    // Functor.
-    // XOR two spans preserving the anti-aliasing information.
-    // The result is added to the "sl" scanline.
-    //------------------
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class XorFormula,
-             unsigned CoverShift = cover_shift> 
-    struct sbool_xor_spans_aa
-    {
-        enum cover_scale_e
-        {
-            cover_shift = CoverShift,
-            cover_size  = 1 << cover_shift,
-            cover_mask  = cover_size - 1,
-            cover_full  = cover_mask
-        };
-        
-
-        void operator () (const typename Scanline1::const_iterator& span1, 
-                          const typename Scanline2::const_iterator& span2, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            unsigned cover;
-            const typename Scanline1::cover_type* covers1;
-            const typename Scanline2::cover_type* covers2;
-
-            // Calculate the operation code and choose the 
-            // proper combination algorithm.
-            // 0 = Both spans are of AA type
-            // 1 = span1 is solid, span2 is AA
-            // 2 = span1 is AA, span2 is solid
-            // 3 = Both spans are of solid type
-            //-----------------
-            switch((span1->len < 0) | ((span2->len < 0) << 1))
-            {
-            case 0:      // Both are AA spans
-                covers1 = span1->covers;
-                covers2 = span2->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(span2->x < x) covers2 += x - span2->x;
-                do
-                {
-                    cover = XorFormula::calculate(*covers1++, *covers2++);
-                    if(cover) sl.add_cell(x, cover);
-                    ++x;
-                }
-                while(--len);
-                break;
-
-            case 1:      // span1 is solid, span2 is AA
-                covers2 = span2->covers;
-                if(span2->x < x) covers2 += x - span2->x;
-                do
-                {
-                    cover = XorFormula::calculate(*(span1->covers), *covers2++);
-                    if(cover) sl.add_cell(x, cover);
-                    ++x;
-                }
-                while(--len);
-                break;
-
-            case 2:      // span1 is AA, span2 is solid
-                covers1 = span1->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                do
-                {
-                    cover = XorFormula::calculate(*covers1++, *(span2->covers));
-                    if(cover) sl.add_cell(x, cover);
-                    ++x;
-                }
-                while(--len);
-                break;
-
-            case 3:      // Both are solid spans
-                cover = XorFormula::calculate(*(span1->covers), *(span2->covers));
-                if(cover) sl.add_span(x, len, cover);
-                break;
-
-            }
-        }
-    };
-
-
-
-
-
-    //-----------------------------------------------sbool_subtract_spans_aa
-    // Functor.
-    // Unite two spans preserving the anti-aliasing information.
-    // The result is added to the "sl" scanline.
-    //------------------
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             unsigned CoverShift = cover_shift> 
-    struct sbool_subtract_spans_aa
-    {
-        enum cover_scale_e
-        {
-            cover_shift = CoverShift,
-            cover_size  = 1 << cover_shift,
-            cover_mask  = cover_size - 1,
-            cover_full  = cover_mask
-        };
-        
-
-        void operator () (const typename Scanline1::const_iterator& span1, 
-                          const typename Scanline2::const_iterator& span2, 
-                          int x, unsigned len, 
-                          Scanline& sl) const
-        {
-            unsigned cover;
-            const typename Scanline1::cover_type* covers1;
-            const typename Scanline2::cover_type* covers2;
-
-            // Calculate the operation code and choose the 
-            // proper combination algorithm.
-            // 0 = Both spans are of AA type
-            // 1 = span1 is solid, span2 is AA
-            // 2 = span1 is AA, span2 is solid
-            // 3 = Both spans are of solid type
-            //-----------------
-            switch((span1->len < 0) | ((span2->len < 0) << 1))
-            {
-            case 0:      // Both are AA spans
-                covers1 = span1->covers;
-                covers2 = span2->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(span2->x < x) covers2 += x - span2->x;
-                do
-                {
-                    cover = *covers1++ * (cover_mask - *covers2++);
-                    if(cover)
-                    {
-                        sl.add_cell(x, 
-                                    (cover == cover_full * cover_full) ?
-                                    cover_full : 
-                                    (cover >> cover_shift));
-                    }
-                    ++x;
-                }
-                while(--len);
-                break;
-
-            case 1:      // span1 is solid, span2 is AA
-                covers2 = span2->covers;
-                if(span2->x < x) covers2 += x - span2->x;
-                do
-                {
-                    cover = *(span1->covers) * (cover_mask - *covers2++);
-                    if(cover)
-                    {
-                        sl.add_cell(x, 
-                                    (cover == cover_full * cover_full) ?
-                                    cover_full : 
-                                    (cover >> cover_shift));
-                    }
-                    ++x;
-                }
-                while(--len);
-                break;
-
-            case 2:      // span1 is AA, span2 is solid
-                covers1 = span1->covers;
-                if(span1->x < x) covers1 += x - span1->x;
-                if(*(span2->covers) != cover_full)
-                {
-                    do
-                    {
-                        cover = *covers1++ * (cover_mask - *(span2->covers));
-                        if(cover)
-                        {
-                            sl.add_cell(x, 
-                                        (cover == cover_full * cover_full) ?
-                                        cover_full : 
-                                        (cover >> cover_shift));
-                        }
-                        ++x;
-                    }
-                    while(--len);
-                }
-                break;
-
-            case 3:      // Both are solid spans
-                cover = *(span1->covers) * (cover_mask - *(span2->covers));
-                if(cover)
-                {
-                    sl.add_span(x, len, 
-                                (cover == cover_full * cover_full) ?
-                                cover_full : 
-                                (cover >> cover_shift));
-                }
-                break;
-            }
-        }
-    };
-
-
-
-
-
-
-    //--------------------------------------------sbool_add_spans_and_render
-    template<class Scanline1, 
-             class Scanline, 
-             class Renderer, 
-             class AddSpanFunctor>
-    void sbool_add_spans_and_render(const Scanline1& sl1, 
-                                    Scanline& sl, 
-                                    Renderer& ren, 
-                                    AddSpanFunctor add_span)
-    {
-        sl.reset_spans();
-        typename Scanline1::const_iterator span = sl1.begin();
-        unsigned num_spans = sl1.num_spans();
-        for(;;)
-        {
-            add_span(span, span->x, abs((int)span->len), sl);
-            if(--num_spans == 0) break;
-            ++span;
-        }
-        sl.finalize(sl1.y());
-        ren.render(sl);
-    }
-
-
-
-
-
-
-
-    //---------------------------------------------sbool_intersect_scanlines
-    // Intersect two scanlines, "sl1" and "sl2" and generate a new "sl" one.
-    // The combine_spans functor can be of type sbool_combine_spans_bin or
-    // sbool_intersect_spans_aa. First is a general functor to combine
-    // two spans without Anti-Aliasing, the second preserves the AA
-    // information, but works slower
-    //
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class CombineSpansFunctor>
-    void sbool_intersect_scanlines(const Scanline1& sl1, 
-                                   const Scanline2& sl2, 
-                                   Scanline& sl, 
-                                   CombineSpansFunctor combine_spans)
-    {
-        sl.reset_spans();
-
-        unsigned num1 = sl1.num_spans();
-        if(num1 == 0) return;
-
-        unsigned num2 = sl2.num_spans();
-        if(num2 == 0) return;
-
-        typename Scanline1::const_iterator span1 = sl1.begin();
-        typename Scanline2::const_iterator span2 = sl2.begin();
-
-        while(num1 && num2)
-        {
-            int xb1 = span1->x;
-            int xb2 = span2->x;
-            int xe1 = xb1 + abs((int)span1->len) - 1;
-            int xe2 = xb2 + abs((int)span2->len) - 1;
-
-            // Determine what spans we should advance in the next step
-            // The span with the least ending X should be advanced
-            // advance_both is just an optimization when we ending 
-            // coordinates are the same and we can advance both
-            //--------------
-            bool advance_span1 = xe1 <  xe2;
-            bool advance_both  = xe1 == xe2;
-
-            // Find the intersection of the spans
-            // and check if they intersect
-            //--------------
-            if(xb1 < xb2) xb1 = xb2;
-            if(xe1 > xe2) xe1 = xe2;
-            if(xb1 <= xe1)
-            {
-                combine_spans(span1, span2, xb1, xe1 - xb1 + 1, sl);
-            }
-
-            // Advance the spans
-            //--------------
-            if(advance_both)
-            {
-                --num1;
-                --num2;
-                if(num1) ++span1;
-                if(num2) ++span2;
-            }
-            else
-            {
-                if(advance_span1)
-                {
-                    --num1;
-                    if(num1) ++span1;
-                }
-                else
-                {
-                    --num2;
-                    if(num2) ++span2;
-                }
-            }
-        }
-    }
-
-
-
-
-
-
-
-
-    //------------------------------------------------sbool_intersect_shapes
-    // Intersect the scanline shapes. Here the "Scanline Generator" 
-    // abstraction is used. ScanlineGen1 and ScanlineGen2 are 
-    // the generators, and can be of type rasterizer_scanline_aa<>.
-    // There function requires three scanline containers that can be of
-    // different types.
-    // "sl1" and "sl2" are used to retrieve scanlines from the generators,
-    // "sl" is ised as the resulting scanline to render it.
-    // The external "sl1" and "sl2" are used only for the sake of
-    // optimization and reusing of the scanline objects.
-    // the function calls sbool_intersect_scanlines with CombineSpansFunctor 
-    // as the last argument. See sbool_intersect_scanlines for details.
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer,
-             class CombineSpansFunctor>
-    void sbool_intersect_shapes(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                Scanline1& sl1, Scanline2& sl2,
-                                Scanline& sl, Renderer& ren, 
-                                CombineSpansFunctor combine_spans)
-    {
-        // Prepare the scanline generators.
-        // If anyone of them doesn't contain 
-        // any scanlines, then return.
-        //-----------------
-        if(!sg1.rewind_scanlines()) return;
-        if(!sg2.rewind_scanlines()) return;
-
-        // Get the bounding boxes
-        //----------------
-        rect_i r1(sg1.min_x(), sg1.min_y(), sg1.max_x(), sg1.max_y());
-        rect_i r2(sg2.min_x(), sg2.min_y(), sg2.max_x(), sg2.max_y());
-
-        // Calculate the intersection of the bounding 
-        // boxes and return if they don't intersect.
-        //-----------------
-        rect_i ir = intersect_rectangles(r1, r2);
-        if(!ir.is_valid()) return;
-
-        // Reset the scanlines and get two first ones
-        //-----------------
-        sl.reset(ir.x1, ir.x2);
-        sl1.reset(sg1.min_x(), sg1.max_x());
-        sl2.reset(sg2.min_x(), sg2.max_x());
-        if(!sg1.sweep_scanline(sl1)) return;
-        if(!sg2.sweep_scanline(sl2)) return;
-
-        ren.prepare();
-
-        // The main loop
-        // Here we synchronize the scanlines with 
-        // the same Y coordinate, ignoring all other ones.
-        // Only scanlines having the same Y-coordinate 
-        // are to be combined.
-        //-----------------
-        for(;;)
-        {
-            while(sl1.y() < sl2.y())
-            {
-                if(!sg1.sweep_scanline(sl1)) return;
-            }
-            while(sl2.y() < sl1.y())
-            {
-                if(!sg2.sweep_scanline(sl2)) return;
-            }
-
-            if(sl1.y() == sl2.y())
-            {
-                // The Y coordinates are the same.
-                // Combine the scanlines, render if they contain any spans,
-                // and advance both generators to the next scanlines
-                //----------------------
-                sbool_intersect_scanlines(sl1, sl2, sl, combine_spans);
-                if(sl.num_spans())
-                {
-                    sl.finalize(sl1.y());
-                    ren.render(sl);
-                }
-                if(!sg1.sweep_scanline(sl1)) return;
-                if(!sg2.sweep_scanline(sl2)) return;
-            }
-        }
-    }
-
-
-
-
-
-
-
-    //-------------------------------------------------sbool_unite_scanlines
-    // Unite two scanlines, "sl1" and "sl2" and generate a new "sl" one.
-    // The combine_spans functor can be of type sbool_combine_spans_bin or
-    // sbool_intersect_spans_aa. First is a general functor to combine
-    // two spans without Anti-Aliasing, the second preserves the AA
-    // information, but works slower
-    //
-    template<class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class AddSpanFunctor1,
-             class AddSpanFunctor2,
-             class CombineSpansFunctor>
-    void sbool_unite_scanlines(const Scanline1& sl1, 
-                               const Scanline2& sl2, 
-                               Scanline& sl, 
-                               AddSpanFunctor1 add_span1,
-                               AddSpanFunctor2 add_span2,
-                               CombineSpansFunctor combine_spans)
-    {
-        sl.reset_spans();
-
-        unsigned num1 = sl1.num_spans();
-        unsigned num2 = sl2.num_spans();
-
-        typename Scanline1::const_iterator span1;// = sl1.begin();
-        typename Scanline2::const_iterator span2;// = sl2.begin();
-
-        enum invalidation_e 
-        { 
-            invalid_b = 0xFFFFFFF, 
-            invalid_e = invalid_b - 1 
-        };
-
-        // Initialize the spans as invalid
-        //---------------
-        int xb1 = invalid_b;
-        int xb2 = invalid_b;
-        int xe1 = invalid_e;
-        int xe2 = invalid_e;
-
-        // Initialize span1 if there are spans
-        //---------------
-        if(num1)
-        {
-            span1 = sl1.begin();
-            xb1 = span1->x;
-            xe1 = xb1 + abs((int)span1->len) - 1;
-            --num1;
-        }
-
-        // Initialize span2 if there are spans
-        //---------------
-        if(num2)
-        {
-            span2 = sl2.begin();
-            xb2 = span2->x;
-            xe2 = xb2 + abs((int)span2->len) - 1;
-            --num2;
-        }
-
-
-        for(;;)
-        {
-            // Retrieve a new span1 if it's invalid
-            //----------------
-            if(num1 && xb1 > xe1) 
-            {
-                --num1;
-                ++span1;
-                xb1 = span1->x;
-                xe1 = xb1 + abs((int)span1->len) - 1;
-            }
-
-            // Retrieve a new span2 if it's invalid
-            //----------------
-            if(num2 && xb2 > xe2) 
-            {
-                --num2;
-                ++span2;
-                xb2 = span2->x;
-                xe2 = xb2 + abs((int)span2->len) - 1;
-            }
-
-            if(xb1 > xe1 && xb2 > xe2) break;
-
-            // Calculate the intersection
-            //----------------
-            int xb = xb1;
-            int xe = xe1;
-            if(xb < xb2) xb = xb2;
-            if(xe > xe2) xe = xe2;
-            int len = xe - xb + 1; // The length of the intersection
-            if(len > 0)
-            {
-                // The spans intersect,
-                // add the beginning of the span
-                //----------------
-                if(xb1 < xb2)
-                {
-                    add_span1(span1, xb1, xb2 - xb1, sl);
-                    xb1 = xb2;
-                }
-                else
-                if(xb2 < xb1)
-                {
-                    add_span2(span2, xb2, xb1 - xb2, sl);
-                    xb2 = xb1;
-                }
-
-                // Add the combination part of the spans
-                //----------------
-                combine_spans(span1, span2, xb, len, sl);
-
-
-                // Invalidate the fully processed span or both
-                //----------------
-                if(xe1 < xe2)
-                {
-                    // Invalidate span1 and eat
-                    // the processed part of span2
-                    //--------------
-                    xb1 = invalid_b;    
-                    xe1 = invalid_e;
-                    xb2 += len;
-                }
-                else
-                if(xe2 < xe1)
-                {
-                    // Invalidate span2 and eat
-                    // the processed part of span1
-                    //--------------
-                    xb2 = invalid_b;  
-                    xe2 = invalid_e;
-                    xb1 += len;
-                }
-                else
-                {
-                    xb1 = invalid_b;  // Invalidate both
-                    xb2 = invalid_b;
-                    xe1 = invalid_e;
-                    xe2 = invalid_e;
-                }
-            }
-            else
-            {
-                // The spans do not intersect
-                //--------------
-                if(xb1 < xb2) 
-                {
-                    // Advance span1
-                    //---------------
-                    if(xb1 <= xe1)
-                    {
-                        add_span1(span1, xb1, xe1 - xb1 + 1, sl);
-                    }
-                    xb1 = invalid_b; // Invalidate
-                    xe1 = invalid_e;
-                }
-                else
-                {
-                    // Advance span2
-                    //---------------
-                    if(xb2 <= xe2)
-                    {
-                        add_span2(span2, xb2, xe2 - xb2 + 1, sl);
-                    }
-                    xb2 = invalid_b; // Invalidate
-                    xe2 = invalid_e;
-                }
-            }
-        }
-    }
-
-
-
-
-    //----------------------------------------------------sbool_unite_shapes
-    // Unite the scanline shapes. Here the "Scanline Generator" 
-    // abstraction is used. ScanlineGen1 and ScanlineGen2 are 
-    // the generators, and can be of type rasterizer_scanline_aa<>.
-    // There function requires three scanline containers that can be 
-    // of different type.
-    // "sl1" and "sl2" are used to retrieve scanlines from the generators,
-    // "sl" is ised as the resulting scanline to render it.
-    // The external "sl1" and "sl2" are used only for the sake of
-    // optimization and reusing of the scanline objects.
-    // the function calls sbool_unite_scanlines with CombineSpansFunctor 
-    // as the last argument. See sbool_unite_scanlines for details.
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer,
-             class AddSpanFunctor1,
-             class AddSpanFunctor2,
-             class CombineSpansFunctor>
-    void sbool_unite_shapes(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                            Scanline1& sl1, Scanline2& sl2,
-                            Scanline& sl, Renderer& ren, 
-                            AddSpanFunctor1 add_span1,
-                            AddSpanFunctor2 add_span2,
-                            CombineSpansFunctor combine_spans)
-    {
-        // Prepare the scanline generators.
-        // If anyone of them doesn't contain 
-        // any scanlines, then return.
-        //-----------------
-        bool flag1 = sg1.rewind_scanlines();
-        bool flag2 = sg2.rewind_scanlines();
-        if(!flag1 && !flag2) return;
-
-        // Get the bounding boxes
-        //----------------
-        rect_i r1(sg1.min_x(), sg1.min_y(), sg1.max_x(), sg1.max_y());
-        rect_i r2(sg2.min_x(), sg2.min_y(), sg2.max_x(), sg2.max_y());
-
-        // Calculate the union of the bounding boxes
-        //-----------------
-        rect_i ur(1,1,0,0);
-             if(flag1 && flag2) ur = unite_rectangles(r1, r2);
-        else if(flag1)          ur = r1;
-        else if(flag2)          ur = r2;
-
-        if(!ur.is_valid()) return;
-
-        ren.prepare();
-
-        // Reset the scanlines and get two first ones
-        //-----------------
-        sl.reset(ur.x1, ur.x2);
-        if(flag1) 
-        {
-            sl1.reset(sg1.min_x(), sg1.max_x());
-            flag1 = sg1.sweep_scanline(sl1);
-        }
-
-        if(flag2) 
-        {
-            sl2.reset(sg2.min_x(), sg2.max_x());
-            flag2 = sg2.sweep_scanline(sl2);
-        }
-
-        // The main loop
-        // Here we synchronize the scanlines with 
-        // the same Y coordinate.
-        //-----------------
-        while(flag1 || flag2)
-        {
-            if(flag1 && flag2)
-            {
-                if(sl1.y() == sl2.y())
-                {
-                    // The Y coordinates are the same.
-                    // Combine the scanlines, render if they contain any spans,
-                    // and advance both generators to the next scanlines
-                    //----------------------
-                    sbool_unite_scanlines(sl1, sl2, sl, 
-                                          add_span1, add_span2, combine_spans);
-                    if(sl.num_spans())
-                    {
-                        sl.finalize(sl1.y());
-                        ren.render(sl);
-                    }
-                    flag1 = sg1.sweep_scanline(sl1);
-                    flag2 = sg2.sweep_scanline(sl2);
-                }
-                else
-                {
-                    if(sl1.y() < sl2.y())
-                    {
-                        sbool_add_spans_and_render(sl1, sl, ren, add_span1);
-                        flag1 = sg1.sweep_scanline(sl1);
-                    }
-                    else
-                    {
-                        sbool_add_spans_and_render(sl2, sl, ren, add_span2);
-                        flag2 = sg2.sweep_scanline(sl2);
-                    }
-                }
-            }
-            else
-            {
-                if(flag1)
-                {
-                    sbool_add_spans_and_render(sl1, sl, ren, add_span1);
-                    flag1 = sg1.sweep_scanline(sl1);
-                }
-                if(flag2)
-                {
-                    sbool_add_spans_and_render(sl2, sl, ren, add_span2);
-                    flag2 = sg2.sweep_scanline(sl2);
-                }
-            }
-        }
-    }
-
-
-
-
-
-
-
-
-    //-------------------------------------------------sbool_subtract_shapes
-    // Subtract the scanline shapes, "sg1-sg2". Here the "Scanline Generator" 
-    // abstraction is used. ScanlineGen1 and ScanlineGen2 are 
-    // the generators, and can be of type rasterizer_scanline_aa<>.
-    // There function requires three scanline containers that can be of
-    // different types.
-    // "sl1" and "sl2" are used to retrieve scanlines from the generators,
-    // "sl" is ised as the resulting scanline to render it.
-    // The external "sl1" and "sl2" are used only for the sake of
-    // optimization and reusing of the scanline objects.
-    // the function calls sbool_intersect_scanlines with CombineSpansFunctor 
-    // as the last argument. See combine_scanlines_sub for details.
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer,
-             class AddSpanFunctor1,
-             class CombineSpansFunctor>
-    void sbool_subtract_shapes(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                               Scanline1& sl1, Scanline2& sl2,
-                               Scanline& sl, Renderer& ren, 
-                               AddSpanFunctor1 add_span1,
-                               CombineSpansFunctor combine_spans)
-    {
-        // Prepare the scanline generators.
-        // Here "sg1" is master, "sg2" is slave.
-        //-----------------
-        if(!sg1.rewind_scanlines()) return;
-        bool flag2 = sg2.rewind_scanlines();
-
-        // Get the bounding box
-        //----------------
-        rect_i r1(sg1.min_x(), sg1.min_y(), sg1.max_x(), sg1.max_y());
-
-        // Reset the scanlines and get two first ones
-        //-----------------
-        sl.reset(sg1.min_x(), sg1.max_x());
-        sl1.reset(sg1.min_x(), sg1.max_x());
-        sl2.reset(sg2.min_x(), sg2.max_x());
-        if(!sg1.sweep_scanline(sl1)) return;
-
-        if(flag2) flag2 = sg2.sweep_scanline(sl2);
-
-        ren.prepare();
-
-        // A fake span2 processor
-        sbool_add_span_empty<Scanline2, Scanline> add_span2;
-
-        // The main loop
-        // Here we synchronize the scanlines with 
-        // the same Y coordinate, ignoring all other ones.
-        // Only scanlines having the same Y-coordinate 
-        // are to be combined.
-        //-----------------
-        bool flag1 = true;
-        do
-        {
-            // Synchronize "slave" with "master"
-            //-----------------
-            while(flag2 && sl2.y() < sl1.y())
-            {
-                flag2 = sg2.sweep_scanline(sl2);
-            }
-
-
-            if(flag2 && sl2.y() == sl1.y())
-            {
-                // The Y coordinates are the same.
-                // Combine the scanlines and render if they contain any spans.
-                //----------------------
-                sbool_unite_scanlines(sl1, sl2, sl, add_span1, add_span2, combine_spans);
-                if(sl.num_spans())
-                {
-                    sl.finalize(sl1.y());
-                    ren.render(sl);
-                }
-            }
-            else
-            {
-                sbool_add_spans_and_render(sl1, sl, ren, add_span1);
-            }
-
-            // Advance the "master"
-            flag1 = sg1.sweep_scanline(sl1);
-        }
-        while(flag1);
-    }
-
-
-
-
-
-
-
-    //---------------------------------------------sbool_intersect_shapes_aa
-    // Intersect two anti-aliased scanline shapes. 
-    // Here the "Scanline Generator" abstraction is used. 
-    // ScanlineGen1 and ScanlineGen2 are the generators, and can be of 
-    // type rasterizer_scanline_aa<>. There function requires three 
-    // scanline containers that can be of different types.
-    // "sl1" and "sl2" are used to retrieve scanlines from the generators,
-    // "sl" is ised as the resulting scanline to render it.
-    // The external "sl1" and "sl2" are used only for the sake of
-    // optimization and reusing of the scanline objects.
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_intersect_shapes_aa(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                   Scanline1& sl1, Scanline2& sl2,
-                                   Scanline& sl, Renderer& ren)
-    {
-        sbool_intersect_spans_aa<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_intersect_shapes(sg1, sg2, sl1, sl2, sl, ren, combine_functor);
-    }
-
-
-
-
-
-    //--------------------------------------------sbool_intersect_shapes_bin
-    // Intersect two binary scanline shapes (without anti-aliasing). 
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_intersect_shapes_bin(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                    Scanline1& sl1, Scanline2& sl2,
-                                    Scanline& sl, Renderer& ren)
-    {
-        sbool_combine_spans_bin<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_intersect_shapes(sg1, sg2, sl1, sl2, sl, ren, combine_functor);
-    }
-
-
-
-
-
-    //-------------------------------------------------sbool_unite_shapes_aa
-    // Unite two anti-aliased scanline shapes 
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_unite_shapes_aa(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                               Scanline1& sl1, Scanline2& sl2,
-                               Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_aa<Scanline1, Scanline> add_functor1;
-        sbool_add_span_aa<Scanline2, Scanline> add_functor2;
-        sbool_unite_spans_aa<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_unite_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                           add_functor1, add_functor2, combine_functor);
-    }
-
-
-
-
-
-    //------------------------------------------------sbool_unite_shapes_bin
-    // Unite two binary scanline shapes (without anti-aliasing). 
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_unite_shapes_bin(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                Scanline1& sl1, Scanline2& sl2,
-                                Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_bin<Scanline1, Scanline> add_functor1;
-        sbool_add_span_bin<Scanline2, Scanline> add_functor2;
-        sbool_combine_spans_bin<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_unite_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                           add_functor1, add_functor2, combine_functor);
-    }
-
-
-
-
-
-
-
-
-
-    //---------------------------------------------------sbool_xor_shapes_aa
-    // Apply eXclusive OR to two anti-aliased scanline shapes. There's 
-    // a modified "Linear" XOR used instead of classical "Saddle" one.
-    // The reason is to have the result absolutely conststent with what
-    // the scanline rasterizer produces.
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_xor_shapes_aa(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                             Scanline1& sl1, Scanline2& sl2,
-                             Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_aa<Scanline1, Scanline> add_functor1;
-        sbool_add_span_aa<Scanline2, Scanline> add_functor2;
-        sbool_xor_spans_aa<Scanline1, Scanline2, Scanline, 
-                           sbool_xor_formula_linear<> > combine_functor;
-        sbool_unite_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                           add_functor1, add_functor2, combine_functor);
-    }
-
-
-
-    //------------------------------------------sbool_xor_shapes_saddle_aa
-    // Apply eXclusive OR to two anti-aliased scanline shapes. 
-    // There's the classical "Saddle" used to calculate the 
-    // Anti-Aliasing values, that is:
-    // a XOR b : 1-((1-a+a*b)*(1-b+a*b))
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_xor_shapes_saddle_aa(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                    Scanline1& sl1, Scanline2& sl2,
-                                    Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_aa<Scanline1, Scanline> add_functor1;
-        sbool_add_span_aa<Scanline2, Scanline> add_functor2;
-        sbool_xor_spans_aa<Scanline1, 
-                           Scanline2, 
-                           Scanline, 
-                           sbool_xor_formula_saddle<> > combine_functor;
-        sbool_unite_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                           add_functor1, add_functor2, combine_functor);
-    }
-
-
-    //--------------------------------------sbool_xor_shapes_abs_diff_aa
-    // Apply eXclusive OR to two anti-aliased scanline shapes. 
-    // There's the absolute difference used to calculate 
-    // Anti-Aliasing values, that is:
-    // a XOR b : abs(a-b)
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_xor_shapes_abs_diff_aa(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                      Scanline1& sl1, Scanline2& sl2,
-                                      Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_aa<Scanline1, Scanline> add_functor1;
-        sbool_add_span_aa<Scanline2, Scanline> add_functor2;
-        sbool_xor_spans_aa<Scanline1, 
-                           Scanline2, 
-                           Scanline, 
-                           sbool_xor_formula_abs_diff> combine_functor;
-        sbool_unite_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                           add_functor1, add_functor2, combine_functor);
-    }
-
-
-
-    //--------------------------------------------------sbool_xor_shapes_bin
-    // Apply eXclusive OR to two binary scanline shapes (without anti-aliasing). 
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_xor_shapes_bin(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                              Scanline1& sl1, Scanline2& sl2,
-                              Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_bin<Scanline1, Scanline> add_functor1;
-        sbool_add_span_bin<Scanline2, Scanline> add_functor2;
-        sbool_combine_spans_empty<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_unite_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                           add_functor1, add_functor2, combine_functor);
-    }
-
-
-
-
-
-
-    //----------------------------------------------sbool_subtract_shapes_aa
-    // Subtract shapes "sg1-sg2" with anti-aliasing
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_subtract_shapes_aa(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                  Scanline1& sl1, Scanline2& sl2,
-                                  Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_aa<Scanline1, Scanline> add_functor;
-        sbool_subtract_spans_aa<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_subtract_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                              add_functor, combine_functor);
-    }
-
-
-
-
-
-    //---------------------------------------------sbool_subtract_shapes_bin
-    // Subtract binary shapes "sg1-sg2" without anti-aliasing
-    // See intersect_shapes_aa for more comments
-    //----------
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_subtract_shapes_bin(ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                   Scanline1& sl1, Scanline2& sl2,
-                                   Scanline& sl, Renderer& ren)
-    {
-        sbool_add_span_bin<Scanline1, Scanline> add_functor;
-        sbool_combine_spans_empty<Scanline1, Scanline2, Scanline> combine_functor;
-        sbool_subtract_shapes(sg1, sg2, sl1, sl2, sl, ren, 
-                              add_functor, combine_functor);
-    }
-
-
-
-
-
-
-    //------------------------------------------------------------sbool_op_e
-    enum sbool_op_e
-    {
-        sbool_or,            //----sbool_or
-        sbool_and,           //----sbool_and
-        sbool_xor,           //----sbool_xor
-        sbool_xor_saddle,    //----sbool_xor_saddle
-        sbool_xor_abs_diff,  //----sbool_xor_abs_diff
-        sbool_a_minus_b,     //----sbool_a_minus_b
-        sbool_b_minus_a      //----sbool_b_minus_a
-    };
-
-
-
-
-
-
-    //----------------------------------------------sbool_combine_shapes_bin
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_combine_shapes_bin(sbool_op_e op,
-                                  ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                  Scanline1& sl1, Scanline2& sl2,
-                                  Scanline& sl, Renderer& ren)
-    {
-        switch(op)
-        {
-        case sbool_or          : sbool_unite_shapes_bin    (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_and         : sbool_intersect_shapes_bin(sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_xor         :
-        case sbool_xor_saddle  : 
-        case sbool_xor_abs_diff: sbool_xor_shapes_bin      (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_a_minus_b   : sbool_subtract_shapes_bin (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_b_minus_a   : sbool_subtract_shapes_bin (sg2, sg1, sl2, sl1, sl, ren); break;
-        }
-    }
-
-
-
-
-    //-----------------------------------------------sbool_combine_shapes_aa
-    template<class ScanlineGen1, 
-             class ScanlineGen2, 
-             class Scanline1, 
-             class Scanline2, 
-             class Scanline, 
-             class Renderer>
-    void sbool_combine_shapes_aa(sbool_op_e op,
-                                 ScanlineGen1& sg1, ScanlineGen2& sg2,
-                                 Scanline1& sl1, Scanline2& sl2,
-                                 Scanline& sl, Renderer& ren)
-    {
-        switch(op)
-        {
-        case sbool_or          : sbool_unite_shapes_aa       (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_and         : sbool_intersect_shapes_aa   (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_xor         : sbool_xor_shapes_aa         (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_xor_saddle  : sbool_xor_shapes_saddle_aa  (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_xor_abs_diff: sbool_xor_shapes_abs_diff_aa(sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_a_minus_b   : sbool_subtract_shapes_aa    (sg1, sg2, sl1, sl2, sl, ren); break;
-        case sbool_b_minus_a   : sbool_subtract_shapes_aa    (sg2, sg1, sl2, sl1, sl, ren); break;
-        }
-    }
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_scanline_storage_aa.h b/xs/src/agg/agg_scanline_storage_aa.h
deleted file mode 100644
index 4c6ed5708..000000000
--- a/xs/src/agg/agg_scanline_storage_aa.h
+++ /dev/null
@@ -1,816 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for 32-bit screen coordinates has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SCANLINE_STORAGE_AA_INCLUDED
-#define AGG_SCANLINE_STORAGE_AA_INCLUDED
-
-#include <string.h>
-#include <stdlib.h>
-#include <math.h>
-#include <limits>
-#include "agg_array.h"
-
-
-namespace agg
-{
-
-    //----------------------------------------------scanline_cell_storage
-    template<class T> class scanline_cell_storage
-    {
-        struct extra_span
-        {
-            unsigned len;
-            T*       ptr;
-        };
-
-    public:
-        typedef T value_type;
-
-        //---------------------------------------------------------------
-        ~scanline_cell_storage()
-        {
-            remove_all();
-        }
-
-        //---------------------------------------------------------------
-        scanline_cell_storage() :
-            m_cells(128-2),
-            m_extra_storage()
-        {}
-
-
-        // Copying
-        //---------------------------------------------------------------
-        scanline_cell_storage(const scanline_cell_storage<T>& v) :
-            m_cells(v.m_cells),
-            m_extra_storage()
-        {
-            copy_extra_storage(v);
-        }
-
-        //---------------------------------------------------------------
-        const scanline_cell_storage<T>& 
-        operator = (const scanline_cell_storage<T>& v)
-        {
-            remove_all();
-            m_cells = v.m_cells;
-            copy_extra_storage(v);
-            return *this;
-        }
-
-        //---------------------------------------------------------------
-        void remove_all()
-        {
-            int i;
-            for(i = m_extra_storage.size()-1; i >= 0; --i)
-            {
-                pod_allocator<T>::deallocate(m_extra_storage[i].ptr,
-                                             m_extra_storage[i].len);
-            }
-            m_extra_storage.remove_all();
-            m_cells.remove_all();
-        }
-
-        //---------------------------------------------------------------
-        int add_cells(const T* cells, unsigned num_cells)
-        {
-            int idx = m_cells.allocate_continuous_block(num_cells);
-            if(idx >= 0)
-            {
-                T* ptr = &m_cells[idx];
-                memcpy(ptr, cells, sizeof(T) * num_cells);
-                return idx;
-            }
-            extra_span s;
-            s.len = num_cells;
-            s.ptr = pod_allocator<T>::allocate(num_cells);
-            memcpy(s.ptr, cells, sizeof(T) * num_cells);
-            m_extra_storage.add(s);
-            return -int(m_extra_storage.size());
-        }
-
-        //---------------------------------------------------------------
-        const T* operator [] (int idx) const
-        {
-            if(idx >= 0)
-            {
-                if((unsigned)idx >= m_cells.size()) return 0;
-                return &m_cells[(unsigned)idx];
-            }
-            unsigned i = unsigned(-idx - 1);
-            if(i >= m_extra_storage.size()) return 0;
-            return m_extra_storage[i].ptr;
-        }
-
-        //---------------------------------------------------------------
-        T* operator [] (int idx)
-        {
-            if(idx >= 0)
-            {
-                if((unsigned)idx >= m_cells.size()) return 0;
-                return &m_cells[(unsigned)idx];
-            }
-            unsigned i = unsigned(-idx - 1);
-            if(i >= m_extra_storage.size()) return 0;
-            return m_extra_storage[i].ptr;
-        }
-
-    private:
-        void copy_extra_storage(const scanline_cell_storage<T>& v)
-        {
-            unsigned i;
-            for(i = 0; i < v.m_extra_storage.size(); ++i)
-            {
-                const extra_span& src = v.m_extra_storage[i];
-                extra_span dst;
-                dst.len = src.len;
-                dst.ptr = pod_allocator<T>::allocate(dst.len);
-                memcpy(dst.ptr, src.ptr, dst.len * sizeof(T));
-                m_extra_storage.add(dst);
-            }
-        }
-
-        pod_bvector<T, 12>         m_cells;
-        pod_bvector<extra_span, 6> m_extra_storage;
-    };
-
-
-
-
-
-
-    //-----------------------------------------------scanline_storage_aa
-    template<class T> class scanline_storage_aa
-    {
-    public:
-        typedef T cover_type;
-
-        //---------------------------------------------------------------
-        struct span_data
-        {
-            int32 x;
-            int32 len;       // If negative, it's a solid span, covers is valid
-            int   covers_id; // The index of the cells in the scanline_cell_storage
-        };
-
-        //---------------------------------------------------------------
-        struct scanline_data
-        {
-            int      y;
-            unsigned num_spans;
-            unsigned start_span;
-        };
-
-
-        //---------------------------------------------------------------
-        class embedded_scanline
-        {
-        public:
-
-            //-----------------------------------------------------------
-            class const_iterator
-            {
-            public:
-                struct span
-                {
-                    int32    x;
-                    int32    len; // If negative, it's a solid span, covers is valid
-                    const T* covers;
-                };
-
-                const_iterator() : m_storage(0) {}
-                const_iterator(embedded_scanline& sl) :
-                    m_storage(sl.m_storage),
-                    m_span_idx(sl.m_scanline.start_span)
-                {
-                    init_span();
-                }
-
-                const span& operator*()  const { return m_span;  }
-                const span* operator->() const { return &m_span; }
-
-                void operator ++ ()
-                {
-                    ++m_span_idx;
-                    init_span();
-                }
-
-            private:
-                void init_span()
-                {
-                    const span_data& s = m_storage->span_by_index(m_span_idx);
-                    m_span.x      = s.x;
-                    m_span.len    = s.len;
-                    m_span.covers = m_storage->covers_by_index(s.covers_id);
-                }
-
-                scanline_storage_aa* m_storage;
-                unsigned                   m_span_idx;
-                span                       m_span;
-            };
-
-            friend class const_iterator;
-
-
-            //-----------------------------------------------------------
-            embedded_scanline(const scanline_storage_aa& storage) :
-                m_storage(&storage)
-            {
-                init(0);
-            }
-
-            //-----------------------------------------------------------
-            void     reset(int, int)     {}
-            unsigned num_spans()   const { return m_scanline.num_spans;  }
-            int      y()           const { return m_scanline.y;          }
-            const_iterator begin() const { return const_iterator(*this); }
-
-            //-----------------------------------------------------------
-            void init(unsigned scanline_idx)
-            {
-                m_scanline_idx = scanline_idx;
-                m_scanline = m_storage->scanline_by_index(m_scanline_idx);
-            }
-
-        private:
-            const scanline_storage_aa* m_storage;
-            scanline_data              m_scanline;
-            unsigned                   m_scanline_idx;
-        };
-
-
-        //---------------------------------------------------------------
-        scanline_storage_aa() :
-            m_covers(),
-            m_spans(256-2),         // Block increment size
-            m_scanlines(),
-            m_min_x(std::numeric_limits<int>::max()),
-            m_min_y(std::numeric_limits<int>::max()),
-            m_max_x(std::numeric_limits<int>::min()),
-            m_max_y(std::numeric_limits<int>::min()),
-            m_cur_scanline(0)
-        {
-            m_fake_scanline.y = 0;
-            m_fake_scanline.num_spans = 0;
-            m_fake_scanline.start_span = 0;
-            m_fake_span.x = 0;
-            m_fake_span.len = 0;
-            m_fake_span.covers_id = 0;
-        }
-
-        // Renderer Interface
-        //---------------------------------------------------------------
-        void prepare()
-        {
-            m_covers.remove_all();
-            m_scanlines.remove_all();
-            m_spans.remove_all();
-            m_min_x = std::numeric_limits<int>::max();
-            m_min_y = std::numeric_limits<int>::max();
-            m_max_x = std::numeric_limits<int>::min();
-            m_max_y = std::numeric_limits<int>::min();
-            m_cur_scanline = 0;
-        }
-
-        //---------------------------------------------------------------
-        template<class Scanline> void render(const Scanline& sl)
-        {
-            scanline_data sl_this;
-
-            int y = sl.y();
-            if(y < m_min_y) m_min_y = y;
-            if(y > m_max_y) m_max_y = y;
-
-            sl_this.y = y;
-            sl_this.num_spans = sl.num_spans();
-            sl_this.start_span = m_spans.size();
-            typename Scanline::const_iterator span_iterator = sl.begin();
-
-            unsigned num_spans = sl_this.num_spans;
-            for(;;)
-            {
-                span_data sp;
-
-                sp.x         = span_iterator->x;
-                sp.len       = span_iterator->len;
-                int len      = abs(int(sp.len));
-                sp.covers_id = 
-                    m_covers.add_cells(span_iterator->covers, 
-                                       unsigned(len));
-                m_spans.add(sp);
-                int x1 = sp.x;
-                int x2 = sp.x + len - 1;
-                if(x1 < m_min_x) m_min_x = x1;
-                if(x2 > m_max_x) m_max_x = x2;
-                if(--num_spans == 0) break;
-                ++span_iterator;
-            }
-            m_scanlines.add(sl_this);
-        }
-
-
-        //---------------------------------------------------------------
-        // Iterate scanlines interface
-        int min_x() const { return m_min_x; }
-        int min_y() const { return m_min_y; }
-        int max_x() const { return m_max_x; }
-        int max_y() const { return m_max_y; }
-
-        //---------------------------------------------------------------
-        bool rewind_scanlines()
-        {
-            m_cur_scanline = 0;
-            return m_scanlines.size() > 0;
-        }
-
-
-        //---------------------------------------------------------------
-        template<class Scanline> bool sweep_scanline(Scanline& sl)
-        {
-            sl.reset_spans();
-            for(;;)
-            {
-                if(m_cur_scanline >= m_scanlines.size()) return false;
-                const scanline_data& sl_this = m_scanlines[m_cur_scanline];
-
-                unsigned num_spans = sl_this.num_spans;
-                unsigned span_idx  = sl_this.start_span;
-                do
-                {
-                    const span_data& sp = m_spans[span_idx++];
-                    const T* covers = covers_by_index(sp.covers_id);
-                    if(sp.len < 0)
-                    {
-                        sl.add_span(sp.x, unsigned(-sp.len), *covers);
-                    }
-                    else
-                    {
-                        sl.add_cells(sp.x, sp.len, covers);
-                    }
-                }
-                while(--num_spans);
-                ++m_cur_scanline;
-                if(sl.num_spans())
-                {
-                    sl.finalize(sl_this.y);
-                    break;
-                }
-            }
-            return true;
-        }
-
-
-        //---------------------------------------------------------------
-        // Specialization for embedded_scanline
-        bool sweep_scanline(embedded_scanline& sl)
-        {
-            do
-            {
-                if(m_cur_scanline >= m_scanlines.size()) return false;
-                sl.init(m_cur_scanline);
-                ++m_cur_scanline;
-            }
-            while(sl.num_spans() == 0);
-            return true;
-        }
-
-        //---------------------------------------------------------------
-        unsigned byte_size() const
-        {
-            unsigned i;
-            unsigned size = sizeof(int32) * 4; // min_x, min_y, max_x, max_y
-
-            for(i = 0; i < m_scanlines.size(); ++i)
-            {
-                size += sizeof(int32) * 3; // scanline size in bytes, Y, num_spans
-
-                const scanline_data& sl_this = m_scanlines[i];
-
-                unsigned num_spans = sl_this.num_spans;
-                unsigned span_idx  = sl_this.start_span;
-                do
-                {
-                    const span_data& sp = m_spans[span_idx++];
-
-                    size += sizeof(int32) * 2;                // X, span_len
-                    if(sp.len < 0)
-                    {
-                        size += sizeof(T);                    // cover
-                    }
-                    else
-                    {
-                        size += sizeof(T) * unsigned(sp.len); // covers
-                    }
-                }
-                while(--num_spans);
-            }
-            return size;
-        }
-
-
-        //---------------------------------------------------------------
-        static void write_int32(int8u* dst, int32 val)
-        {
-            dst[0] = ((const int8u*)&val)[0];
-            dst[1] = ((const int8u*)&val)[1];
-            dst[2] = ((const int8u*)&val)[2];
-            dst[3] = ((const int8u*)&val)[3];
-        }
-
-
-        //---------------------------------------------------------------
-        void serialize(int8u* data) const
-        {
-            unsigned i;
-
-            write_int32(data, min_x()); // min_x
-            data += sizeof(int32);
-            write_int32(data, min_y()); // min_y
-            data += sizeof(int32);
-            write_int32(data, max_x()); // max_x
-            data += sizeof(int32);
-            write_int32(data, max_y()); // max_y
-            data += sizeof(int32);
-
-            for(i = 0; i < m_scanlines.size(); ++i)
-            {
-                const scanline_data& sl_this = m_scanlines[i];
-                
-                int8u* size_ptr = data;
-                data += sizeof(int32);  // Reserve space for scanline size in bytes
-
-                write_int32(data, sl_this.y);            // Y
-                data += sizeof(int32);
-
-                write_int32(data, sl_this.num_spans);    // num_spans
-                data += sizeof(int32);
-
-                unsigned num_spans = sl_this.num_spans;
-                unsigned span_idx  = sl_this.start_span;
-                do
-                {
-                    const span_data& sp = m_spans[span_idx++];
-                    const T* covers = covers_by_index(sp.covers_id);
-
-                    write_int32(data, sp.x);            // X
-                    data += sizeof(int32);
-
-                    write_int32(data, sp.len);          // span_len
-                    data += sizeof(int32);
-
-                    if(sp.len < 0)
-                    {
-                        memcpy(data, covers, sizeof(T));
-                        data += sizeof(T);
-                    }
-                    else
-                    {
-                        memcpy(data, covers, unsigned(sp.len) * sizeof(T));
-                        data += sizeof(T) * unsigned(sp.len);
-                    }
-                }
-                while(--num_spans);
-                write_int32(size_ptr, int32(unsigned(data - size_ptr)));
-            }
-        }
-
-
-        //---------------------------------------------------------------
-        const scanline_data& scanline_by_index(unsigned i) const
-        {
-            return (i < m_scanlines.size()) ? m_scanlines[i] : m_fake_scanline;
-        }
-
-        //---------------------------------------------------------------
-        const span_data& span_by_index(unsigned i) const
-        {
-            return (i < m_spans.size()) ? m_spans[i] : m_fake_span;
-        }
-
-        //---------------------------------------------------------------
-        const T* covers_by_index(int i) const
-        {
-            return m_covers[i];
-        }
-
-    private:
-        scanline_cell_storage<T>      m_covers;
-        pod_bvector<span_data, 10>    m_spans;
-        pod_bvector<scanline_data, 8> m_scanlines;
-        span_data     m_fake_span;
-        scanline_data m_fake_scanline;
-        int           m_min_x;
-        int           m_min_y;
-        int           m_max_x;
-        int           m_max_y;
-        unsigned      m_cur_scanline;
-    };
-
-
-    typedef scanline_storage_aa<int8u>  scanline_storage_aa8;  //--------scanline_storage_aa8
-    typedef scanline_storage_aa<int16u> scanline_storage_aa16; //--------scanline_storage_aa16
-    typedef scanline_storage_aa<int32u> scanline_storage_aa32; //--------scanline_storage_aa32
-
-
-
-
-    //------------------------------------------serialized_scanlines_adaptor_aa
-    template<class T> class serialized_scanlines_adaptor_aa
-    {
-    public:
-        typedef T cover_type;
-
-        //---------------------------------------------------------------------
-        class embedded_scanline
-        {
-        public:
-            typedef T cover_type;
-
-            //-----------------------------------------------------------------
-            class const_iterator
-            {
-            public:
-                struct span
-                {
-                    int32    x;
-                    int32    len; // If negative, it's a solid span, "covers" is valid
-                    const T* covers; 
-                };
-
-                const_iterator() : m_ptr(0) {}
-                const_iterator(const embedded_scanline* sl) :
-                    m_ptr(sl->m_ptr),
-                    m_dx(sl->m_dx)
-                {
-                    init_span();
-                }
-
-                const span& operator*()  const { return m_span;  }
-                const span* operator->() const { return &m_span; }
-
-                void operator ++ ()
-                {
-                    if(m_span.len < 0) 
-                    {
-                        m_ptr += sizeof(T);
-                    }
-                    else 
-                    {
-                        m_ptr += m_span.len * sizeof(T);
-                    }
-                    init_span();
-                }
-
-            private:
-                int read_int32()
-                {
-                    int32 val;
-                    ((int8u*)&val)[0] = *m_ptr++;
-                    ((int8u*)&val)[1] = *m_ptr++;
-                    ((int8u*)&val)[2] = *m_ptr++;
-                    ((int8u*)&val)[3] = *m_ptr++;
-                    return val;
-                }
-
-                void init_span()
-                {
-                    m_span.x      = read_int32() + m_dx;
-                    m_span.len    = read_int32();
-                    m_span.covers = m_ptr;
-                }
-
-                const int8u* m_ptr;
-                span         m_span;
-                int          m_dx;
-            };
-
-            friend class const_iterator;
-
-
-            //-----------------------------------------------------------------
-            embedded_scanline() : m_ptr(0), m_y(0), m_num_spans(0) {}
-
-            //-----------------------------------------------------------------
-            void     reset(int, int)     {}
-            unsigned num_spans()   const { return m_num_spans;  }
-            int      y()           const { return m_y;          }
-            const_iterator begin() const { return const_iterator(this); }
-
-
-        private:
-            //-----------------------------------------------------------------
-            int read_int32()
-            {
-                int32 val;
-                ((int8u*)&val)[0] = *m_ptr++;
-                ((int8u*)&val)[1] = *m_ptr++;
-                ((int8u*)&val)[2] = *m_ptr++;
-                ((int8u*)&val)[3] = *m_ptr++;
-                return val;
-            }
-
-        public:
-            //-----------------------------------------------------------------
-            void init(const int8u* ptr, int dx, int dy)
-            {
-                m_ptr       = ptr;
-                m_y         = read_int32() + dy;
-                m_num_spans = unsigned(read_int32());
-                m_dx        = dx;
-            }
-
-        private:
-            const int8u* m_ptr;
-            int          m_y;
-            unsigned     m_num_spans;
-            int          m_dx;
-        };
-
-
-
-    public:
-        //--------------------------------------------------------------------
-        serialized_scanlines_adaptor_aa() :
-            m_data(0),
-            m_end(0),
-            m_ptr(0),
-            m_dx(0),
-            m_dy(0),
-            m_min_x(std::numeric_limits<int>::max()),
-            m_min_y(std::numeric_limits<int>::max()),
-            m_max_x(std::numeric_limits<int>::min()),
-            m_max_y(std::numeric_limits<int>::min())
-        {}
-
-        //--------------------------------------------------------------------
-        serialized_scanlines_adaptor_aa(const int8u* data, unsigned size,
-                                        double dx, double dy) :
-            m_data(data),
-            m_end(data + size),
-            m_ptr(data),
-            m_dx(iround(dx)),
-            m_dy(iround(dy)),
-            m_min_x(std::numeric_limits<int>::max()),
-            m_min_y(std::numeric_limits<int>::max()),
-            m_max_x(std::numeric_limits<int>::min()),
-            m_max_y(std::numeric_limits<int>::min())
-        {}
-
-        //--------------------------------------------------------------------
-        void init(const int8u* data, unsigned size, double dx, double dy)
-        {
-            m_data  = data;
-            m_end   = data + size;
-            m_ptr   = data;
-            m_dx    = iround(dx);
-            m_dy    = iround(dy);
-            m_min_x = std::numeric_limits<int>::max();
-            m_min_y = std::numeric_limits<int>::max();
-            m_max_x = std::numeric_limits<int>::min();
-            m_max_y = std::numeric_limits<int>::min();
-        }
-
-    private:
-        //--------------------------------------------------------------------
-        int read_int32()
-        {
-            int32 val;
-            ((int8u*)&val)[0] = *m_ptr++;
-            ((int8u*)&val)[1] = *m_ptr++;
-            ((int8u*)&val)[2] = *m_ptr++;
-            ((int8u*)&val)[3] = *m_ptr++;
-            return val;
-        }
-
-        //--------------------------------------------------------------------
-        unsigned read_int32u()
-        {
-            int32u val;
-            ((int8u*)&val)[0] = *m_ptr++;
-            ((int8u*)&val)[1] = *m_ptr++;
-            ((int8u*)&val)[2] = *m_ptr++;
-            ((int8u*)&val)[3] = *m_ptr++;
-            return val;
-        }
-        
-    public:
-        // Iterate scanlines interface
-        //--------------------------------------------------------------------
-        bool rewind_scanlines()
-        {
-            m_ptr = m_data;
-            if(m_ptr < m_end)
-            {
-                m_min_x = read_int32() + m_dx; 
-                m_min_y = read_int32() + m_dy;
-                m_max_x = read_int32() + m_dx;
-                m_max_y = read_int32() + m_dy;
-            }
-            return m_ptr < m_end;
-        }
-
-        //--------------------------------------------------------------------
-        int min_x() const { return m_min_x; }
-        int min_y() const { return m_min_y; }
-        int max_x() const { return m_max_x; }
-        int max_y() const { return m_max_y; }
-
-        //--------------------------------------------------------------------
-        template<class Scanline> bool sweep_scanline(Scanline& sl)
-        {
-            sl.reset_spans();
-            for(;;)
-            {
-                if(m_ptr >= m_end) return false;
-
-                read_int32();      // Skip scanline size in bytes
-                int y = read_int32() + m_dy;
-                unsigned num_spans = read_int32();
-
-                do
-                {
-                    int x = read_int32() + m_dx;
-                    int len = read_int32();
-
-                    if(len < 0)
-                    {
-                        sl.add_span(x, unsigned(-len), *m_ptr);
-                        m_ptr += sizeof(T);
-                    }
-                    else
-                    {
-                        sl.add_cells(x, len, m_ptr);
-                        m_ptr += len * sizeof(T);
-                    }
-                }
-                while(--num_spans);
-
-                if(sl.num_spans())
-                {
-                    sl.finalize(y);
-                    break;
-                }
-            }
-            return true;
-        }
-
-
-        //--------------------------------------------------------------------
-        // Specialization for embedded_scanline
-        bool sweep_scanline(embedded_scanline& sl)
-        {
-            do
-            {
-                if(m_ptr >= m_end) return false;
-
-                unsigned byte_size = read_int32u();
-                sl.init(m_ptr, m_dx, m_dy);
-                m_ptr += byte_size - sizeof(int32);
-            }
-            while(sl.num_spans() == 0);
-            return true;
-        }
-
-    private:
-        const int8u* m_data;
-        const int8u* m_end;
-        const int8u* m_ptr;
-        int          m_dx;
-        int          m_dy;
-        int          m_min_x;
-        int          m_min_y;
-        int          m_max_x;
-        int          m_max_y;
-    };
-
-
-
-    typedef serialized_scanlines_adaptor_aa<int8u>  serialized_scanlines_adaptor_aa8;  //----serialized_scanlines_adaptor_aa8
-    typedef serialized_scanlines_adaptor_aa<int16u> serialized_scanlines_adaptor_aa16; //----serialized_scanlines_adaptor_aa16
-    typedef serialized_scanlines_adaptor_aa<int32u> serialized_scanlines_adaptor_aa32; //----serialized_scanlines_adaptor_aa32
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_scanline_storage_bin.h b/xs/src/agg/agg_scanline_storage_bin.h
deleted file mode 100644
index 0018d4ba6..000000000
--- a/xs/src/agg/agg_scanline_storage_bin.h
+++ /dev/null
@@ -1,587 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for 32-bit screen coordinates has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-
-#ifndef AGG_SCANLINE_STORAGE_BIN_INCLUDED
-#define AGG_SCANLINE_STORAGE_BIN_INCLUDED
-
-#include <string.h>
-#include <stdlib.h>
-#include <math.h>
-#include <limits>
-#include "agg_array.h"
-
-
-namespace agg
-{
-
-    //-----------------------------------------------scanline_storage_bin
-    class scanline_storage_bin
-    {
-    public:
-        //---------------------------------------------------------------
-        struct span_data
-        {
-            int32 x;
-            int32 len;
-        };
-
-        //---------------------------------------------------------------
-        struct scanline_data
-        {
-            int      y;
-            unsigned num_spans;
-            unsigned start_span;
-        };
-
-
-        //---------------------------------------------------------------
-        class embedded_scanline
-        {
-        public:
-
-            //-----------------------------------------------------------
-            class const_iterator
-            {
-            public:
-                const_iterator() : m_storage(0) {}
-                const_iterator(const embedded_scanline* sl) :
-                    m_storage(sl->m_storage),
-                    m_span_idx(sl->m_scanline.start_span)
-                {
-                    m_span = m_storage->span_by_index(m_span_idx);
-                }
-
-                const span_data& operator*()  const { return m_span;  }
-                const span_data* operator->() const { return &m_span; }
-
-                void operator ++ ()
-                {
-                    ++m_span_idx;
-                    m_span = m_storage->span_by_index(m_span_idx);
-                }
-
-            private:
-                const scanline_storage_bin* m_storage;
-                unsigned                    m_span_idx;
-                span_data                   m_span;
-            };
-
-            friend class const_iterator;
-
-
-            //-----------------------------------------------------------
-            embedded_scanline(scanline_storage_bin& storage) :
-                m_storage(&storage)
-            {
-                setup(0);
-            }
-
-            //-----------------------------------------------------------
-            void     reset(int, int)     {}
-            unsigned num_spans()   const { return m_scanline.num_spans;  }
-            int      y()           const { return m_scanline.y;          }
-            const_iterator begin() const { return const_iterator(this); }
-
-            //-----------------------------------------------------------
-            void setup(unsigned scanline_idx)
-            {
-                m_scanline_idx = scanline_idx;
-                m_scanline = m_storage->scanline_by_index(m_scanline_idx);
-            }
-
-        private:
-            scanline_storage_bin*       m_storage;
-            scanline_data               m_scanline;
-            unsigned                    m_scanline_idx;
-        };
-
-
-        //---------------------------------------------------------------
-        scanline_storage_bin() :
-            m_spans(256-2),         // Block increment size
-            m_scanlines(),
-            m_min_x(std::numeric_limits<int>::max()),
-            m_min_y(std::numeric_limits<int>::max()),
-            m_max_x(std::numeric_limits<int>::min()),
-            m_max_y(std::numeric_limits<int>::min()),
-            m_cur_scanline(0)
-        {
-            m_fake_scanline.y = 0;
-            m_fake_scanline.num_spans = 0;
-            m_fake_scanline.start_span = 0;
-            m_fake_span.x = 0;
-            m_fake_span.len = 0;
-        }
-
-        // Renderer Interface
-        //---------------------------------------------------------------
-        void prepare()
-        {
-            m_scanlines.remove_all();
-            m_spans.remove_all();
-            m_min_x = std::numeric_limits<int>::max();
-            m_min_y = std::numeric_limits<int>::max();
-            m_max_x = std::numeric_limits<int>::min();
-            m_max_y = std::numeric_limits<int>::min();
-            m_cur_scanline = 0;
-        }
-
-        //---------------------------------------------------------------
-        template<class Scanline> void render(const Scanline& sl)
-        {
-            scanline_data sl_this;
-
-            int y = sl.y();
-            if(y < m_min_y) m_min_y = y;
-            if(y > m_max_y) m_max_y = y;
-
-            sl_this.y = y;
-            sl_this.num_spans = sl.num_spans();
-            sl_this.start_span = m_spans.size();
-            typename Scanline::const_iterator span_iterator = sl.begin();
-
-            unsigned num_spans = sl_this.num_spans;
-            for(;;)
-            {
-                span_data sp;
-                sp.x   = span_iterator->x;
-                sp.len = (int32)abs((int)(span_iterator->len));
-                m_spans.add(sp);
-                int x1 = sp.x;
-                int x2 = sp.x + sp.len - 1;
-                if(x1 < m_min_x) m_min_x = x1;
-                if(x2 > m_max_x) m_max_x = x2;
-                if(--num_spans == 0) break;
-                ++span_iterator;
-            }
-            m_scanlines.add(sl_this);
-        }
-
-
-        //---------------------------------------------------------------
-        // Iterate scanlines interface
-        int min_x() const { return m_min_x; }
-        int min_y() const { return m_min_y; }
-        int max_x() const { return m_max_x; }
-        int max_y() const { return m_max_y; }
-
-        //---------------------------------------------------------------
-        bool rewind_scanlines()
-        {
-            m_cur_scanline = 0;
-            return m_scanlines.size() > 0;
-        }
-
-
-        //---------------------------------------------------------------
-        template<class Scanline> bool sweep_scanline(Scanline& sl)
-        {
-            sl.reset_spans();
-            for(;;)
-            {
-                if(m_cur_scanline >= m_scanlines.size()) return false;
-                const scanline_data& sl_this = m_scanlines[m_cur_scanline];
-
-                unsigned num_spans = sl_this.num_spans;
-                unsigned span_idx  = sl_this.start_span;
-                do
-                {
-                    const span_data& sp = m_spans[span_idx++];
-                    sl.add_span(sp.x, sp.len, cover_full);
-                }
-                while(--num_spans);
-
-                ++m_cur_scanline;
-                if(sl.num_spans())
-                {
-                    sl.finalize(sl_this.y);
-                    break;
-                }
-            }
-            return true;
-        }
-
-
-        //---------------------------------------------------------------
-        // Specialization for embedded_scanline
-        bool sweep_scanline(embedded_scanline& sl)
-        {
-            do
-            {
-                if(m_cur_scanline >= m_scanlines.size()) return false;
-                sl.setup(m_cur_scanline);
-                ++m_cur_scanline;
-            }
-            while(sl.num_spans() == 0);
-            return true;
-        }
-
-
-        //---------------------------------------------------------------
-        unsigned byte_size() const
-        {
-            unsigned i;
-            unsigned size = sizeof(int32) * 4; // min_x, min_y, max_x, max_y
-
-            for(i = 0; i < m_scanlines.size(); ++i)
-            {
-                size += sizeof(int32) * 2 + // Y, num_spans
-                        unsigned(m_scanlines[i].num_spans) * sizeof(int32) * 2; // X, span_len
-            }
-            return size;
-        }
-
-
-        //---------------------------------------------------------------
-        static void write_int32(int8u* dst, int32 val)
-        {
-            dst[0] = ((const int8u*)&val)[0];
-            dst[1] = ((const int8u*)&val)[1];
-            dst[2] = ((const int8u*)&val)[2];
-            dst[3] = ((const int8u*)&val)[3];
-        }
-
-
-        //---------------------------------------------------------------
-        void serialize(int8u* data) const
-        {
-            unsigned i;
-
-            write_int32(data, min_x()); // min_x
-            data += sizeof(int32);
-            write_int32(data, min_y()); // min_y
-            data += sizeof(int32);
-            write_int32(data, max_x()); // max_x
-            data += sizeof(int32);
-            write_int32(data, max_y()); // max_y
-            data += sizeof(int32);
-
-            for(i = 0; i < m_scanlines.size(); ++i)
-            {
-                const scanline_data& sl_this = m_scanlines[i];
-
-                write_int32(data, sl_this.y);            // Y
-                data += sizeof(int32);
-
-                write_int32(data, sl_this.num_spans);    // num_spans
-                data += sizeof(int32);
-
-                unsigned num_spans = sl_this.num_spans;
-                unsigned span_idx  = sl_this.start_span;
-                do
-                {
-                    const span_data& sp = m_spans[span_idx++];
-
-                    write_int32(data, sp.x);             // X
-                    data += sizeof(int32);
-
-                    write_int32(data, sp.len);           // len
-                    data += sizeof(int32);
-                }
-                while(--num_spans);
-            }
-        }
-
-
-        //---------------------------------------------------------------
-        const scanline_data& scanline_by_index(unsigned i) const
-        {
-            return (i < m_scanlines.size()) ? m_scanlines[i] : m_fake_scanline;
-        }
-
-        //---------------------------------------------------------------
-        const span_data& span_by_index(unsigned i) const
-        {
-            return (i < m_spans.size()) ? m_spans[i] : m_fake_span;
-        }
-
-
-    private:
-        pod_bvector<span_data, 10>    m_spans;
-        pod_bvector<scanline_data, 8> m_scanlines;
-        span_data     m_fake_span;
-        scanline_data m_fake_scanline;
-        int           m_min_x;
-        int           m_min_y;
-        int           m_max_x;
-        int           m_max_y;
-        unsigned      m_cur_scanline;
-    };
-
-
-
-
-
-
-
-
-
-
-
-
-
-    //---------------------------------------serialized_scanlines_adaptor_bin
-    class serialized_scanlines_adaptor_bin
-    {
-    public:
-        typedef bool cover_type;
-
-        //--------------------------------------------------------------------
-        class embedded_scanline
-        {
-        public:
-
-            //----------------------------------------------------------------
-            class const_iterator
-            {
-            public:
-                struct span
-                {
-                    int32 x;
-                    int32 len;
-                };
-
-                const_iterator() : m_ptr(0) {}
-                const_iterator(const embedded_scanline* sl) :
-                    m_ptr(sl->m_ptr),
-                    m_dx(sl->m_dx)
-                {
-                    m_span.x   = read_int32() + m_dx;
-                    m_span.len = read_int32();
-                }
-
-                const span& operator*()  const { return m_span;  }
-                const span* operator->() const { return &m_span; }
-
-                void operator ++ ()
-                {
-                    m_span.x   = read_int32() + m_dx;
-                    m_span.len = read_int32();
-                }
-
-            private:
-                int read_int32()
-                {
-                    int32 val;
-                    ((int8u*)&val)[0] = *m_ptr++;
-                    ((int8u*)&val)[1] = *m_ptr++;
-                    ((int8u*)&val)[2] = *m_ptr++;
-                    ((int8u*)&val)[3] = *m_ptr++;
-                    return val;
-                }
-
-                const int8u* m_ptr;
-                span         m_span;
-                int          m_dx;
-            };
-
-            friend class const_iterator;
-
-
-            //----------------------------------------------------------------
-            embedded_scanline() : m_ptr(0), m_y(0), m_num_spans(0) {}
-
-            //----------------------------------------------------------------
-            void     reset(int, int)     {}
-            unsigned num_spans()   const { return m_num_spans;  }
-            int      y()           const { return m_y;          }
-            const_iterator begin() const { return const_iterator(this); }
-
-
-        private:
-            //----------------------------------------------------------------
-            int read_int32()
-            {
-                int32 val;
-                ((int8u*)&val)[0] = *m_ptr++;
-                ((int8u*)&val)[1] = *m_ptr++;
-                ((int8u*)&val)[2] = *m_ptr++;
-                ((int8u*)&val)[3] = *m_ptr++;
-                return val;
-            }
-
-        public:
-            //----------------------------------------------------------------
-            void init(const int8u* ptr, int dx, int dy)
-            {
-                m_ptr       = ptr;
-                m_y         = read_int32() + dy;
-                m_num_spans = unsigned(read_int32());
-                m_dx        = dx;
-            }
-
-        private:
-            const int8u* m_ptr;
-            int          m_y;
-            unsigned     m_num_spans;
-            int          m_dx;
-        };
-
-
-
-    public:
-        //--------------------------------------------------------------------
-        serialized_scanlines_adaptor_bin() :
-            m_data(0),
-            m_end(0),
-            m_ptr(0),
-            m_dx(0),
-            m_dy(0),
-            m_min_x(std::numeric_limits<int>::max()),
-            m_min_y(std::numeric_limits<int>::max()),
-            m_max_x(std::numeric_limits<int>::min()),
-            m_max_y(std::numeric_limits<int>::min())
-        {}
-
-        //--------------------------------------------------------------------
-        serialized_scanlines_adaptor_bin(const int8u* data, unsigned size,
-                                         double dx, double dy) :
-            m_data(data),
-            m_end(data + size),
-            m_ptr(data),
-            m_dx(iround(dx)),
-            m_dy(iround(dy)),
-            m_min_x(std::numeric_limits<int>::max()),
-            m_min_y(std::numeric_limits<int>::max()),
-            m_max_x(std::numeric_limits<int>::min()),
-            m_max_y(std::numeric_limits<int>::min())
-        {}
-
-        //--------------------------------------------------------------------
-        void init(const int8u* data, unsigned size, double dx, double dy)
-        {
-            m_data  = data;
-            m_end   = data + size;
-            m_ptr   = data;
-            m_dx    = iround(dx);
-            m_dy    = iround(dy);
-            m_min_x = std::numeric_limits<int>::max();
-            m_min_y = std::numeric_limits<int>::max();
-            m_max_x = std::numeric_limits<int>::min();
-            m_max_y = std::numeric_limits<int>::min();
-        }
-
-    private:
-        //--------------------------------------------------------------------
-        int read_int32()
-        {
-            int32 val;
-            ((int8u*)&val)[0] = *m_ptr++;
-            ((int8u*)&val)[1] = *m_ptr++;
-            ((int8u*)&val)[2] = *m_ptr++;
-            ((int8u*)&val)[3] = *m_ptr++;
-            return val;
-        }
-       
-    public:
-        // Iterate scanlines interface
-        //--------------------------------------------------------------------
-        bool rewind_scanlines()
-        {
-            m_ptr = m_data;
-            if(m_ptr < m_end)
-            {
-                m_min_x = read_int32() + m_dx; 
-                m_min_y = read_int32() + m_dy;
-                m_max_x = read_int32() + m_dx;
-                m_max_y = read_int32() + m_dy;
-            }
-            return m_ptr < m_end;
-        }
-
-        //--------------------------------------------------------------------
-        int min_x() const { return m_min_x; }
-        int min_y() const { return m_min_y; }
-        int max_x() const { return m_max_x; }
-        int max_y() const { return m_max_y; }
-
-        //--------------------------------------------------------------------
-        template<class Scanline> bool sweep_scanline(Scanline& sl)
-        {
-            sl.reset_spans();
-            for(;;)
-            {
-                if(m_ptr >= m_end) return false;
-
-                int y = read_int32() + m_dy;
-                unsigned num_spans = read_int32();
-
-                do
-                {
-                    int x = read_int32() + m_dx;
-                    int len = read_int32();
-
-                    if(len < 0) len = -len;
-                    sl.add_span(x, unsigned(len), cover_full);
-                }
-                while(--num_spans);
-
-                if(sl.num_spans())
-                {
-                    sl.finalize(y);
-                    break;
-                }
-            }
-            return true;
-        }
-
-
-        //--------------------------------------------------------------------
-        // Specialization for embedded_scanline
-        bool sweep_scanline(embedded_scanline& sl)
-        {
-            do
-            {
-                if(m_ptr >= m_end) return false;
-
-                sl.init(m_ptr, m_dx, m_dy);
-
-                // Jump to the next scanline
-                //--------------------------
-                read_int32();                    // Y
-                int num_spans = read_int32();    // num_spans
-                m_ptr += num_spans * sizeof(int32) * 2;
-            }
-            while(sl.num_spans() == 0);
-            return true;
-        }
-
-    private:
-        const int8u* m_data;
-        const int8u* m_end;
-        const int8u* m_ptr;
-        int          m_dx;
-        int          m_dy;
-        int          m_min_x;
-        int          m_min_y;
-        int          m_max_x;
-        int          m_max_y;
-    };
-
-
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_scanline_u.h b/xs/src/agg/agg_scanline_u.h
deleted file mode 100644
index 630eb9dea..000000000
--- a/xs/src/agg/agg_scanline_u.h
+++ /dev/null
@@ -1,499 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for 32-bit screen coordinates (scanline32_u) has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SCANLINE_U_INCLUDED
-#define AGG_SCANLINE_U_INCLUDED
-
-#include "agg_array.h"
-
-namespace agg
-{
-    //=============================================================scanline_u8
-    //
-    // Unpacked scanline container class
-    //
-    // This class is used to transfer data from a scanline rasterizer 
-    // to the rendering buffer. It's organized very simple. The class stores 
-    // information of horizontal spans to render it into a pixel-map buffer. 
-    // Each span has staring X, length, and an array of bytes that determine the 
-    // cover-values for each pixel. 
-    // Before using this class you should know the minimal and maximal pixel 
-    // coordinates of your scanline. The protocol of using is:
-    // 1. reset(min_x, max_x)
-    // 2. add_cell() / add_span() - accumulate scanline. 
-    //    When forming one scanline the next X coordinate must be always greater
-    //    than the last stored one, i.e. it works only with ordered coordinates.
-    // 3. Call finalize(y) and render the scanline.
-    // 3. Call reset_spans() to prepare for the new scanline.
-    //    
-    // 4. Rendering:
-    // 
-    // Scanline provides an iterator class that allows you to extract
-    // the spans and the cover values for each pixel. Be aware that clipping
-    // has not been done yet, so you should perform it yourself.
-    // Use scanline_u8::iterator to render spans:
-    //-------------------------------------------------------------------------
-    //
-    // int y = sl.y();                    // Y-coordinate of the scanline
-    //
-    // ************************************
-    // ...Perform vertical clipping here...
-    // ************************************
-    //
-    // scanline_u8::const_iterator span = sl.begin();
-    // 
-    // unsigned char* row = m_rbuf->row(y); // The the address of the beginning 
-    //                                      // of the current row
-    // 
-    // unsigned num_spans = sl.num_spans(); // Number of spans. It's guaranteed that
-    //                                      // num_spans is always greater than 0.
-    //
-    // do
-    // {
-    //     const scanline_u8::cover_type* covers =
-    //         span->covers;                     // The array of the cover values
-    //
-    //     int num_pix = span->len;              // Number of pixels of the span.
-    //                                           // Always greater than 0, still it's
-    //                                           // better to use "int" instead of 
-    //                                           // "unsigned" because it's more
-    //                                           // convenient for clipping
-    //     int x = span->x;
-    //
-    //     **************************************
-    //     ...Perform horizontal clipping here...
-    //     ...you have x, covers, and pix_count..
-    //     **************************************
-    //
-    //     unsigned char* dst = row + x;  // Calculate the start address of the row.
-    //                                    // In this case we assume a simple 
-    //                                    // grayscale image 1-byte per pixel.
-    //     do
-    //     {
-    //         *dst++ = *covers++;        // Hypotetical rendering. 
-    //     }
-    //     while(--num_pix);
-    //
-    //     ++span;
-    // } 
-    // while(--num_spans);  // num_spans cannot be 0, so this loop is quite safe
-    //------------------------------------------------------------------------
-    //
-    // The question is: why should we accumulate the whole scanline when we
-    // could render just separate spans when they're ready?
-    // That's because using the scanline is generally faster. When is consists 
-    // of more than one span the conditions for the processor cash system
-    // are better, because switching between two different areas of memory 
-    // (that can be very large) occurs less frequently.
-    //------------------------------------------------------------------------
-    class scanline_u8
-    {
-    public:
-        typedef scanline_u8 self_type;
-        typedef int8u       cover_type;
-        typedef int16       coord_type;
-
-        //--------------------------------------------------------------------
-        struct span
-        {
-            coord_type  x;
-            coord_type  len;
-            cover_type* covers;
-        };
-
-        typedef span* iterator;
-        typedef const span* const_iterator;
-
-        //--------------------------------------------------------------------
-        scanline_u8() :
-            m_min_x(0),
-            m_last_x(0x7FFFFFF0),
-            m_cur_span(0)
-        {}
-
-        //--------------------------------------------------------------------
-        void reset(int min_x, int max_x)
-        {
-            unsigned max_len = max_x - min_x + 2;
-            if(max_len > m_spans.size())
-            {
-                m_spans.resize(max_len);
-                m_covers.resize(max_len);
-            }
-            m_last_x   = 0x7FFFFFF0;
-            m_min_x    = min_x;
-            m_cur_span = &m_spans[0];
-        }
-
-        //--------------------------------------------------------------------
-        void add_cell(int x, unsigned cover)
-        {
-            x -= m_min_x;
-            m_covers[x] = (cover_type)cover;
-            if(x == m_last_x+1)
-            {
-                m_cur_span->len++;
-            }
-            else
-            {
-                m_cur_span++;
-                m_cur_span->x      = (coord_type)(x + m_min_x);
-                m_cur_span->len    = 1;
-                m_cur_span->covers = &m_covers[x];
-            }
-            m_last_x = x;
-        }
-
-        //--------------------------------------------------------------------
-        void add_cells(int x, unsigned len, const cover_type* covers)
-        {
-            x -= m_min_x;
-            memcpy(&m_covers[x], covers, len * sizeof(cover_type));
-            if(x == m_last_x+1)
-            {
-                m_cur_span->len += (coord_type)len;
-            }
-            else
-            {
-                m_cur_span++;
-                m_cur_span->x      = (coord_type)(x + m_min_x);
-                m_cur_span->len    = (coord_type)len;
-                m_cur_span->covers = &m_covers[x];
-            }
-            m_last_x = x + len - 1;
-        }
-
-        //--------------------------------------------------------------------
-        void add_span(int x, unsigned len, unsigned cover)
-        {
-            x -= m_min_x;
-            memset(&m_covers[x], cover, len);
-            if(x == m_last_x+1)
-            {
-                m_cur_span->len += (coord_type)len;
-            }
-            else
-            {
-                m_cur_span++;
-                m_cur_span->x      = (coord_type)(x + m_min_x);
-                m_cur_span->len    = (coord_type)len;
-                m_cur_span->covers = &m_covers[x];
-            }
-            m_last_x = x + len - 1;
-        }
-
-        //--------------------------------------------------------------------
-        void finalize(int y) 
-        { 
-            m_y = y; 
-        }
-
-        //--------------------------------------------------------------------
-        void reset_spans()
-        {
-            m_last_x    = 0x7FFFFFF0;
-            m_cur_span  = &m_spans[0];
-        }
-
-        //--------------------------------------------------------------------
-        int      y()           const { return m_y; }
-        unsigned num_spans()   const { return unsigned(m_cur_span - &m_spans[0]); }
-        const_iterator begin() const { return &m_spans[1]; }
-        iterator       begin()       { return &m_spans[1]; }
-
-    private:
-        scanline_u8(const self_type&);
-        const self_type& operator = (const self_type&);
-
-    private:
-        int                   m_min_x;
-        int                   m_last_x;
-        int                   m_y;
-        pod_array<cover_type> m_covers;
-        pod_array<span>       m_spans;
-        span*                 m_cur_span;
-    };
-
-
-
-
-    //==========================================================scanline_u8_am
-    // 
-    // The scanline container with alpha-masking
-    // 
-    //------------------------------------------------------------------------
-    template<class AlphaMask> 
-    class scanline_u8_am : public scanline_u8
-    {
-    public:
-        typedef scanline_u8           base_type;
-        typedef AlphaMask             alpha_mask_type;
-        typedef base_type::cover_type cover_type;
-        typedef base_type::coord_type coord_type;
-
-        scanline_u8_am() : base_type(), m_alpha_mask(0) {}
-        scanline_u8_am(AlphaMask& am) : base_type(), m_alpha_mask(&am) {}
-
-        //--------------------------------------------------------------------
-        void finalize(int span_y)
-        {
-            base_type::finalize(span_y);
-            if(m_alpha_mask)
-            {
-                typename base_type::iterator span = base_type::begin();
-                unsigned count = base_type::num_spans();
-                do
-                {
-                    m_alpha_mask->combine_hspan(span->x, 
-                                                base_type::y(), 
-                                                span->covers, 
-                                                span->len);
-                    ++span;
-                }
-                while(--count);
-            }
-        }
-
-    private:
-        AlphaMask* m_alpha_mask;
-    };
-
-
-
-
-    //===========================================================scanline32_u8
-    class scanline32_u8
-    {
-    public:
-        typedef scanline32_u8 self_type;
-        typedef int8u         cover_type;
-        typedef int32         coord_type;
-
-        //--------------------------------------------------------------------
-        struct span
-        {
-            span() {}
-            span(coord_type x_, coord_type len_, cover_type* covers_) :
-                x(x_), len(len_), covers(covers_) {}
-
-            coord_type  x;
-            coord_type  len;
-            cover_type* covers;
-        };
-
-        typedef pod_bvector<span, 4> span_array_type;
-
-        //--------------------------------------------------------------------
-        class const_iterator
-        {
-        public:
-            const_iterator(const span_array_type& spans) :
-                m_spans(spans),
-                m_span_idx(0)
-            {}
-
-            const span& operator*()  const { return m_spans[m_span_idx];  }
-            const span* operator->() const { return &m_spans[m_span_idx]; }
-
-            void operator ++ () { ++m_span_idx; }
-
-        private:
-            const span_array_type& m_spans;
-            unsigned               m_span_idx;
-        };
-
-        //--------------------------------------------------------------------
-        class iterator
-        {
-        public:
-            iterator(span_array_type& spans) :
-                m_spans(spans),
-                m_span_idx(0)
-            {}
-
-            span& operator*()  { return m_spans[m_span_idx];  }
-            span* operator->() { return &m_spans[m_span_idx]; }
-
-            void operator ++ () { ++m_span_idx; }
-
-        private:
-            span_array_type& m_spans;
-            unsigned         m_span_idx;
-        };
-
-
-
-        //--------------------------------------------------------------------
-        scanline32_u8() :
-            m_min_x(0),
-            m_last_x(0x7FFFFFF0),
-            m_covers()
-        {}
-
-        //--------------------------------------------------------------------
-        void reset(int min_x, int max_x)
-        {
-            unsigned max_len = max_x - min_x + 2;
-            if(max_len > m_covers.size())
-            {
-                m_covers.resize(max_len);
-            }
-            m_last_x = 0x7FFFFFF0;
-            m_min_x  = min_x;
-            m_spans.remove_all();
-        }
-
-        //--------------------------------------------------------------------
-        void add_cell(int x, unsigned cover)
-        {
-            x -= m_min_x;
-            m_covers[x] = cover_type(cover);
-            if(x == m_last_x+1)
-            {
-                m_spans.last().len++;
-            }
-            else
-            {
-                m_spans.add(span(coord_type(x + m_min_x), 1, &m_covers[x]));
-            }
-            m_last_x = x;
-        }
-
-        //--------------------------------------------------------------------
-        void add_cells(int x, unsigned len, const cover_type* covers)
-        {
-            x -= m_min_x;
-            memcpy(&m_covers[x], covers, len * sizeof(cover_type));
-            if(x == m_last_x+1)
-            {
-                m_spans.last().len += coord_type(len);
-            }
-            else
-            {
-                m_spans.add(span(coord_type(x + m_min_x), 
-                                 coord_type(len), 
-                                 &m_covers[x]));
-            }
-            m_last_x = x + len - 1;
-        }
-
-        //--------------------------------------------------------------------
-        void add_span(int x, unsigned len, unsigned cover)
-        {
-            x -= m_min_x;
-            memset(&m_covers[x], cover, len);
-            if(x == m_last_x+1)
-            {
-                m_spans.last().len += coord_type(len);
-            }
-            else
-            {
-                m_spans.add(span(coord_type(x + m_min_x), 
-                                 coord_type(len), 
-                                 &m_covers[x]));
-            }
-            m_last_x = x + len - 1;
-        }
-
-        //--------------------------------------------------------------------
-        void finalize(int y) 
-        { 
-            m_y = y; 
-        }
-
-        //--------------------------------------------------------------------
-        void reset_spans()
-        {
-            m_last_x = 0x7FFFFFF0;
-            m_spans.remove_all();
-        }
-
-        //--------------------------------------------------------------------
-        int      y()           const { return m_y; }
-        unsigned num_spans()   const { return m_spans.size(); }
-        const_iterator begin() const { return const_iterator(m_spans); }
-        iterator       begin()       { return iterator(m_spans); }
-
-    private:
-        scanline32_u8(const self_type&);
-        const self_type& operator = (const self_type&);
-
-    private:
-        int                   m_min_x;
-        int                   m_last_x;
-        int                   m_y;
-        pod_array<cover_type> m_covers;
-        span_array_type       m_spans;
-    };
-
-
-
-
-    //========================================================scanline32_u8_am
-    // 
-    // The scanline container with alpha-masking
-    // 
-    //------------------------------------------------------------------------
-    template<class AlphaMask> 
-    class scanline32_u8_am : public scanline32_u8
-    {
-    public:
-        typedef scanline32_u8         base_type;
-        typedef AlphaMask             alpha_mask_type;
-        typedef base_type::cover_type cover_type;
-        typedef base_type::coord_type coord_type;
-
-
-        scanline32_u8_am() : base_type(), m_alpha_mask(0) {}
-        scanline32_u8_am(AlphaMask& am) : base_type(), m_alpha_mask(&am) {}
-
-        //--------------------------------------------------------------------
-        void finalize(int span_y)
-        {
-            base_type::finalize(span_y);
-            if(m_alpha_mask)
-            {
-                typename base_type::iterator span = base_type::begin();
-                unsigned count = base_type::num_spans();
-                do
-                {
-                    m_alpha_mask->combine_hspan(span->x, 
-                                                base_type::y(), 
-                                                span->covers, 
-                                                span->len);
-                    ++span;
-                }
-                while(--count);
-            }
-        }
-
-    private:
-        AlphaMask* m_alpha_mask;
-    };
-
-
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_shorten_path.h b/xs/src/agg/agg_shorten_path.h
deleted file mode 100644
index dd9929ff9..000000000
--- a/xs/src/agg/agg_shorten_path.h
+++ /dev/null
@@ -1,66 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SHORTEN_PATH_INCLUDED
-#define AGG_SHORTEN_PATH_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-
-    //===========================================================shorten_path
-    template<class VertexSequence> 
-    void shorten_path(VertexSequence& vs, double s, unsigned closed = 0)
-    {
-        typedef typename VertexSequence::value_type vertex_type;
-
-        if(s > 0.0 && vs.size() > 1)
-        {
-            double d;
-            int n = int(vs.size() - 2);
-            while(n)
-            {
-                d = vs[n].dist;
-                if(d > s) break;
-                vs.remove_last();
-                s -= d;
-                --n;
-            }
-            if(vs.size() < 2)
-            {
-                vs.remove_all();
-            }
-            else
-            {
-                n = vs.size() - 1;
-                vertex_type& prev = vs[n-1];
-                vertex_type& last = vs[n];
-                d = (prev.dist - s) / prev.dist;
-                double x = prev.x + (last.x - prev.x) * d;
-                double y = prev.y + (last.y - prev.y) * d;
-                last.x = x;
-                last.y = y;
-                if(!prev(last)) vs.remove_last();
-                vs.close(closed != 0);
-            }
-        }
-    }
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_simul_eq.h b/xs/src/agg/agg_simul_eq.h
deleted file mode 100644
index 3d0dce4b4..000000000
--- a/xs/src/agg/agg_simul_eq.h
+++ /dev/null
@@ -1,147 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Solving simultaneous equations
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_SIMUL_EQ_INCLUDED
-#define AGG_SIMUL_EQ_INCLUDED
-
-#include <math.h>
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //=============================================================swap_arrays
-    template<class T> void swap_arrays(T* a1, T* a2, unsigned n)
-    {
-        unsigned i;
-        for(i = 0; i < n; i++)
-        {
-            T tmp = *a1;
-            *a1++ = *a2;
-            *a2++ = tmp;
-        }
-    }
-
-
-    //============================================================matrix_pivot
-    template<unsigned Rows, unsigned Cols>
-    struct matrix_pivot
-    {
-        static int pivot(double m[Rows][Cols], unsigned row)
-        {
-            int k = int(row);
-            double max_val, tmp;
-
-            max_val = -1.0;
-            unsigned i;
-            for(i = row; i < Rows; i++)
-            {
-                if((tmp = fabs(m[i][row])) > max_val && tmp != 0.0)
-                {
-                    max_val = tmp;
-                    k = i;
-                }
-            }
-
-            if(m[k][row] == 0.0)
-            {
-                return -1;
-            }
-
-            if(k != int(row))
-            {
-                swap_arrays(m[k], m[row], Cols);
-                return k;
-            }
-            return 0;
-        }
-    };
-    
-
-
-    //===============================================================simul_eq
-    template<unsigned Size, unsigned RightCols>
-    struct simul_eq
-    {
-        static bool solve(const double left[Size][Size], 
-                          const double right[Size][RightCols],
-                          double result[Size][RightCols])
-        {
-            unsigned i, j, k;
-            double a1;
-
-            double tmp[Size][Size + RightCols];
-
-            for(i = 0; i < Size; i++)
-            {
-                for(j = 0; j < Size; j++)
-                {
-                    tmp[i][j] = left[i][j];
-                } 
-                for(j = 0; j < RightCols; j++)
-                {
-                    tmp[i][Size + j] = right[i][j];
-                }
-            }
-
-            for(k = 0; k < Size; k++)
-            {
-                if(matrix_pivot<Size, Size + RightCols>::pivot(tmp, k) < 0)
-                {
-                    return false; // Singularity....
-                }
-
-                a1 = tmp[k][k];
-
-                for(j = k; j < Size + RightCols; j++)
-                {
-                    tmp[k][j] /= a1;
-                }
-
-                for(i = k + 1; i < Size; i++)
-                {
-                    a1 = tmp[i][k];
-                    for (j = k; j < Size + RightCols; j++)
-                    {
-                        tmp[i][j] -= a1 * tmp[k][j];
-                    }
-                }
-            }
-
-
-            for(k = 0; k < RightCols; k++)
-            {
-                int m;
-                for(m = int(Size - 1); m >= 0; m--)
-                {
-                    result[m][k] = tmp[m][Size + k];
-                    for(j = m + 1; j < Size; j++)
-                    {
-                        result[m][k] -= tmp[m][j] * result[j][k];
-                    }
-                }
-            }
-            return true;
-        }
-
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_allocator.h b/xs/src/agg/agg_span_allocator.h
deleted file mode 100644
index 201b69bb0..000000000
--- a/xs/src/agg/agg_span_allocator.h
+++ /dev/null
@@ -1,54 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_ALLOCATOR_INCLUDED
-#define AGG_SPAN_ALLOCATOR_INCLUDED
-
-#include "agg_array.h"
-
-namespace agg
-{
-    //----------------------------------------------------------span_allocator
-    template<class ColorT> class span_allocator
-    {
-    public:
-        typedef ColorT color_type;
-
-        //--------------------------------------------------------------------
-        AGG_INLINE color_type* allocate(unsigned span_len)
-        {
-            if(span_len > m_span.size())
-            {
-                // To reduce the number of reallocs we align the 
-                // span_len to 256 color elements. 
-                // Well, I just like this number and it looks reasonable.
-                //-----------------------
-                m_span.resize(((span_len + 255) >> 8) << 8);
-            }
-            return &m_span[0];
-        }
-
-        AGG_INLINE color_type* span()               { return &m_span[0]; }
-        AGG_INLINE unsigned    max_span_len() const { return m_span.size(); }
-
-    private:
-        pod_array<color_type> m_span;
-    };
-}
-
-
-#endif
-
-
diff --git a/xs/src/agg/agg_span_converter.h b/xs/src/agg/agg_span_converter.h
deleted file mode 100644
index 91d0f87c2..000000000
--- a/xs/src/agg/agg_span_converter.h
+++ /dev/null
@@ -1,56 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_CONVERTER_INCLUDED
-#define AGG_SPAN_CONVERTER_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //----------------------------------------------------------span_converter
-    template<class SpanGenerator, class SpanConverter> class span_converter
-    {
-    public:
-        typedef typename SpanGenerator::color_type color_type;
-
-        span_converter(SpanGenerator& span_gen, SpanConverter& span_cnv) : 
-            m_span_gen(&span_gen), m_span_cnv(&span_cnv) {}
-
-        void attach_generator(SpanGenerator& span_gen) { m_span_gen = &span_gen; }
-        void attach_converter(SpanConverter& span_cnv) { m_span_cnv = &span_cnv; }
-
-        //--------------------------------------------------------------------
-        void prepare() 
-        { 
-            m_span_gen->prepare(); 
-            m_span_cnv->prepare();
-        }
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            m_span_gen->generate(span, x, y, len);
-            m_span_cnv->generate(span, x, y, len);
-        }
-
-    private:
-        SpanGenerator* m_span_gen;
-        SpanConverter* m_span_cnv;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_gouraud.h b/xs/src/agg/agg_span_gouraud.h
deleted file mode 100644
index 2986c88fe..000000000
--- a/xs/src/agg/agg_span_gouraud.h
+++ /dev/null
@@ -1,172 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_GOURAUD_INCLUDED
-#define AGG_SPAN_GOURAUD_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_math.h"
-
-namespace agg
-{
-
-    //============================================================span_gouraud
-    template<class ColorT> class span_gouraud
-    {
-    public:
-        typedef ColorT color_type;
-
-        struct coord_type
-        {
-            double x;
-            double y;
-            color_type color;
-        };
-
-        //--------------------------------------------------------------------
-        span_gouraud() : 
-            m_vertex(0)
-        {
-            m_cmd[0] = path_cmd_stop;
-        }
-
-        //--------------------------------------------------------------------
-        span_gouraud(const color_type& c1,
-                     const color_type& c2,
-                     const color_type& c3,
-                     double x1, double y1,
-                     double x2, double y2,
-                     double x3, double y3,
-                     double d) : 
-            m_vertex(0)
-        {
-            colors(c1, c2, c3);
-            triangle(x1, y1, x2, y2, x3, y3, d);
-        }
-
-        //--------------------------------------------------------------------
-        void colors(ColorT c1, ColorT c2, ColorT c3)
-        {
-            m_coord[0].color = c1;
-            m_coord[1].color = c2;
-            m_coord[2].color = c3;
-        }
-
-        //--------------------------------------------------------------------
-        // Sets the triangle and dilates it if needed.
-        // The trick here is to calculate beveled joins in the vertices of the 
-        // triangle and render it as a 6-vertex polygon. 
-        // It's necessary to achieve numerical stability. 
-        // However, the coordinates to interpolate colors are calculated
-        // as miter joins (calc_intersection).
-        void triangle(double x1, double y1, 
-                      double x2, double y2,
-                      double x3, double y3,
-                      double d)
-        {
-            m_coord[0].x = m_x[0] = x1; 
-            m_coord[0].y = m_y[0] = y1;
-            m_coord[1].x = m_x[1] = x2; 
-            m_coord[1].y = m_y[1] = y2;
-            m_coord[2].x = m_x[2] = x3; 
-            m_coord[2].y = m_y[2] = y3;
-            m_cmd[0] = path_cmd_move_to;
-            m_cmd[1] = path_cmd_line_to;
-            m_cmd[2] = path_cmd_line_to;
-            m_cmd[3] = path_cmd_stop;
-
-            if(d != 0.0)
-            {   
-                dilate_triangle(m_coord[0].x, m_coord[0].y,
-                                m_coord[1].x, m_coord[1].y,
-                                m_coord[2].x, m_coord[2].y,
-                                m_x, m_y, d);
-
-                calc_intersection(m_x[4], m_y[4], m_x[5], m_y[5],
-                                  m_x[0], m_y[0], m_x[1], m_y[1],
-                                  &m_coord[0].x, &m_coord[0].y);
-
-                calc_intersection(m_x[0], m_y[0], m_x[1], m_y[1],
-                                  m_x[2], m_y[2], m_x[3], m_y[3],
-                                  &m_coord[1].x, &m_coord[1].y);
-
-                calc_intersection(m_x[2], m_y[2], m_x[3], m_y[3],
-                                  m_x[4], m_y[4], m_x[5], m_y[5],
-                                  &m_coord[2].x, &m_coord[2].y);
-                m_cmd[3] = path_cmd_line_to;
-                m_cmd[4] = path_cmd_line_to;
-                m_cmd[5] = path_cmd_line_to;
-                m_cmd[6] = path_cmd_stop;
-            }
-        }
-
-        //--------------------------------------------------------------------
-        // Vertex Source Interface to feed the coordinates to the rasterizer
-        void rewind(unsigned)
-        {
-            m_vertex = 0;
-        }
-
-        //--------------------------------------------------------------------
-        unsigned vertex(double* x, double* y)
-        {
-            *x = m_x[m_vertex];
-            *y = m_y[m_vertex];
-            return m_cmd[m_vertex++];
-        }
-
-    protected:
-        //--------------------------------------------------------------------
-        void arrange_vertices(coord_type* coord) const
-        {
-            coord[0] = m_coord[0];
-            coord[1] = m_coord[1];
-            coord[2] = m_coord[2];
-
-            if(m_coord[0].y > m_coord[2].y)
-            {
-                coord[0] = m_coord[2]; 
-                coord[2] = m_coord[0];
-            }
-
-            coord_type tmp;
-            if(coord[0].y > coord[1].y)
-            {
-                tmp      = coord[1];
-                coord[1] = coord[0];
-                coord[0] = tmp;
-            }
-
-            if(coord[1].y > coord[2].y)
-            {
-                tmp      = coord[2];
-                coord[2] = coord[1];
-                coord[1] = tmp;
-            }
-       }
-
-    private:
-        //--------------------------------------------------------------------
-        coord_type m_coord[3];
-        double m_x[8];
-        double m_y[8];
-        unsigned m_cmd[8];
-        unsigned m_vertex;
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_span_gouraud_gray.h b/xs/src/agg/agg_span_gouraud_gray.h
deleted file mode 100644
index d5fc39d10..000000000
--- a/xs/src/agg/agg_span_gouraud_gray.h
+++ /dev/null
@@ -1,241 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_GOURAUD_GRAY_INCLUDED
-#define AGG_SPAN_GOURAUD_GRAY_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_color_gray.h"
-#include "agg_dda_line.h"
-#include "agg_span_gouraud.h"
-
-namespace agg
-{
-
-    //=======================================================span_gouraud_gray
-    template<class ColorT> class span_gouraud_gray : public span_gouraud<ColorT>
-    {
-    public:
-        typedef ColorT color_type;
-        typedef typename color_type::value_type value_type;
-        typedef span_gouraud<color_type> base_type;
-        typedef typename base_type::coord_type coord_type;
-        enum subpixel_scale_e
-        { 
-            subpixel_shift = 4, 
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-    private:
-        //--------------------------------------------------------------------
-        struct gray_calc
-        {
-            void init(const coord_type& c1, const coord_type& c2)
-            {
-                m_x1  = c1.x - 0.5;
-                m_y1  = c1.y - 0.5;
-                m_dx  = c2.x - c1.x;
-                double dy = c2.y - c1.y;
-                m_1dy = (fabs(dy) < 1e-10) ? 1e10 : 1.0 / dy;
-                m_v1 = c1.color.v;
-                m_a1 = c1.color.a;
-                m_dv = c2.color.v - m_v1;
-                m_da = c2.color.a - m_a1;
-            }
-
-            void calc(double y)
-            {
-                double k = (y - m_y1) * m_1dy;
-                if(k < 0.0) k = 0.0;
-                if(k > 1.0) k = 1.0;
-                m_v = m_v1 + iround(m_dv * k);
-                m_a = m_a1 + iround(m_da * k);
-                m_x = iround((m_x1 + m_dx * k) * subpixel_scale);
-            }
-
-            double m_x1;
-            double m_y1;
-            double m_dx;
-            double m_1dy;
-            int    m_v1;
-            int    m_a1;
-            int    m_dv;
-            int    m_da;
-            int    m_v;
-            int    m_a;
-            int    m_x;
-        };
-
-
-    public:
-        //--------------------------------------------------------------------
-        span_gouraud_gray() {}
-        span_gouraud_gray(const color_type& c1, 
-                          const color_type& c2, 
-                          const color_type& c3,
-                          double x1, double y1, 
-                          double x2, double y2,
-                          double x3, double y3, 
-                          double d = 0) : 
-            base_type(c1, c2, c3, x1, y1, x2, y2, x3, y3, d)
-        {}
-
-        //--------------------------------------------------------------------
-        void prepare()
-        {
-            coord_type coord[3];
-            base_type::arrange_vertices(coord);
-
-            m_y2 = int(coord[1].y);
-
-            m_swap = cross_product(coord[0].x, coord[0].y, 
-                                   coord[2].x, coord[2].y,
-                                   coord[1].x, coord[1].y) < 0.0;
-
-            m_c1.init(coord[0], coord[2]);
-            m_c2.init(coord[0], coord[1]);
-            m_c3.init(coord[1], coord[2]);
-        }
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            m_c1.calc(y);
-            const gray_calc* pc1 = &m_c1;
-            const gray_calc* pc2 = &m_c2;
-
-            if(y < m_y2)
-            {
-                // Bottom part of the triangle (first subtriangle)
-                //-------------------------
-                m_c2.calc(y + m_c2.m_1dy);
-            }
-            else
-            {
-                // Upper part (second subtriangle)
-                //-------------------------
-                m_c3.calc(y - m_c3.m_1dy);
-                pc2 = &m_c3;
-            }
-
-            if(m_swap)
-            {
-                // It means that the triangle is oriented clockwise, 
-                // so that we need to swap the controlling structures
-                //-------------------------
-                const gray_calc* t = pc2;
-                pc2 = pc1;
-                pc1 = t;
-            }
-
-            // Get the horizontal length with subpixel accuracy
-            // and protect it from division by zero
-            //-------------------------
-            int nlen = abs(pc2->m_x - pc1->m_x);
-            if(nlen <= 0) nlen = 1;
-
-            dda_line_interpolator<14> v(pc1->m_v, pc2->m_v, nlen);
-            dda_line_interpolator<14> a(pc1->m_a, pc2->m_a, nlen);
-
-            // Calculate the starting point of the gradient with subpixel 
-            // accuracy and correct (roll back) the interpolators.
-            // This operation will also clip the beginning of the span
-            // if necessary.
-            //-------------------------
-            int start = pc1->m_x - (x << subpixel_shift);
-            v    -= start; 
-            a    -= start;
-            nlen += start;
-
-            int vv, va;
-            enum lim_e { lim = color_type::base_mask };
-
-            // Beginning part of the span. Since we rolled back the 
-            // interpolators, the color values may have overflow.
-            // So that, we render the beginning part with checking 
-            // for overflow. It lasts until "start" is positive;
-            // typically it's 1-2 pixels, but may be more in some cases.
-            //-------------------------
-            while(len && start > 0)
-            {
-                vv = v.y();
-                va = a.y();
-                if(vv < 0) vv = 0; if(vv > lim) vv = lim;
-                if(va < 0) va = 0; if(va > lim) va = lim;
-                span->v = (value_type)vv;
-                span->a = (value_type)va;
-                v     += subpixel_scale; 
-                a     += subpixel_scale;
-                nlen  -= subpixel_scale;
-                start -= subpixel_scale;
-                ++span;
-                --len;
-            }
-
-            // Middle part, no checking for overflow.
-            // Actual spans can be longer than the calculated length
-            // because of anti-aliasing, thus, the interpolators can 
-            // overflow. But while "nlen" is positive we are safe.
-            //-------------------------
-            while(len && nlen > 0)
-            {
-                span->v = (value_type)v.y();
-                span->a = (value_type)a.y();
-                v    += subpixel_scale; 
-                a    += subpixel_scale;
-                nlen -= subpixel_scale;
-                ++span;
-                --len;
-            }
-
-            // Ending part; checking for overflow.
-            // Typically it's 1-2 pixels, but may be more in some cases.
-            //-------------------------
-            while(len)
-            {
-                vv = v.y();
-                va = a.y();
-                if(vv < 0) vv = 0; if(vv > lim) vv = lim;
-                if(va < 0) va = 0; if(va > lim) va = lim;
-                span->v = (value_type)vv;
-                span->a = (value_type)va;
-                v += subpixel_scale; 
-                a += subpixel_scale;
-                ++span;
-                --len;
-            }
-        }
-
-
-    private:
-        bool      m_swap;
-        int       m_y2;
-        gray_calc m_c1;
-        gray_calc m_c2;
-        gray_calc m_c3;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_gouraud_rgba.h b/xs/src/agg/agg_span_gouraud_rgba.h
deleted file mode 100644
index 89192d227..000000000
--- a/xs/src/agg/agg_span_gouraud_rgba.h
+++ /dev/null
@@ -1,277 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_GOURAUD_RGBA_INCLUDED
-#define AGG_SPAN_GOURAUD_RGBA_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_color_rgba.h"
-#include "agg_dda_line.h"
-#include "agg_span_gouraud.h"
-
-namespace agg
-{
-
-    //=======================================================span_gouraud_rgba
-    template<class ColorT> class span_gouraud_rgba : public span_gouraud<ColorT>
-    {
-    public:
-        typedef ColorT color_type;
-        typedef typename ColorT::value_type value_type;
-        typedef span_gouraud<color_type> base_type;
-        typedef typename base_type::coord_type coord_type;
-        enum subpixel_scale_e
-        { 
-            subpixel_shift = 4, 
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-    private:
-        //--------------------------------------------------------------------
-        struct rgba_calc
-        {
-            void init(const coord_type& c1, const coord_type& c2)
-            {
-                m_x1  = c1.x - 0.5; 
-                m_y1  = c1.y - 0.5;
-                m_dx  = c2.x - c1.x;
-                double dy = c2.y - c1.y;
-                m_1dy = (dy < 1e-5) ? 1e5 : 1.0 / dy;
-                m_r1  = c1.color.r;
-                m_g1  = c1.color.g;
-                m_b1  = c1.color.b;
-                m_a1  = c1.color.a;
-                m_dr  = c2.color.r - m_r1;
-                m_dg  = c2.color.g - m_g1;
-                m_db  = c2.color.b - m_b1;
-                m_da  = c2.color.a - m_a1;
-            }
-
-            void calc(double y)
-            {
-                double k = (y - m_y1) * m_1dy;
-                if(k < 0.0) k = 0.0;
-                if(k > 1.0) k = 1.0;
-                m_r = m_r1 + iround(m_dr * k);
-                m_g = m_g1 + iround(m_dg * k);
-                m_b = m_b1 + iround(m_db * k);
-                m_a = m_a1 + iround(m_da * k);
-                m_x = iround((m_x1 + m_dx * k) * subpixel_scale);
-            }
-
-            double m_x1;
-            double m_y1;
-            double m_dx;
-            double m_1dy;
-            int    m_r1;
-            int    m_g1;
-            int    m_b1;
-            int    m_a1;
-            int    m_dr;
-            int    m_dg;
-            int    m_db;
-            int    m_da;
-            int    m_r;
-            int    m_g;
-            int    m_b;
-            int    m_a;
-            int    m_x;
-        };
-
-    public:
-
-        //--------------------------------------------------------------------
-        span_gouraud_rgba() {}
-        span_gouraud_rgba(const color_type& c1, 
-                          const color_type& c2, 
-                          const color_type& c3,
-                          double x1, double y1, 
-                          double x2, double y2,
-                          double x3, double y3, 
-                          double d = 0) : 
-            base_type(c1, c2, c3, x1, y1, x2, y2, x3, y3, d)
-        {}
-
-        //--------------------------------------------------------------------
-        void prepare()
-        {
-            coord_type coord[3];
-            base_type::arrange_vertices(coord);
-
-            m_y2 = int(coord[1].y);
-
-            m_swap = cross_product(coord[0].x, coord[0].y, 
-                                   coord[2].x, coord[2].y,
-                                   coord[1].x, coord[1].y) < 0.0;
-
-            m_rgba1.init(coord[0], coord[2]);
-            m_rgba2.init(coord[0], coord[1]);
-            m_rgba3.init(coord[1], coord[2]);
-        }
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            m_rgba1.calc(y);//(m_rgba1.m_1dy > 2) ? m_rgba1.m_y1 : y);
-            const rgba_calc* pc1 = &m_rgba1;
-            const rgba_calc* pc2 = &m_rgba2;
-
-            if(y <= m_y2)
-            {          
-                // Bottom part of the triangle (first subtriangle)
-                //-------------------------
-                m_rgba2.calc(y + m_rgba2.m_1dy);
-            }
-            else
-            {
-                // Upper part (second subtriangle)
-                m_rgba3.calc(y - m_rgba3.m_1dy);
-                //-------------------------
-                pc2 = &m_rgba3;
-            }
-
-            if(m_swap)
-            {
-                // It means that the triangle is oriented clockwise, 
-                // so that we need to swap the controlling structures
-                //-------------------------
-                const rgba_calc* t = pc2;
-                pc2 = pc1;
-                pc1 = t;
-            }
-
-            // Get the horizontal length with subpixel accuracy
-            // and protect it from division by zero
-            //-------------------------
-            int nlen = abs(pc2->m_x - pc1->m_x);
-            if(nlen <= 0) nlen = 1;
-
-            dda_line_interpolator<14> r(pc1->m_r, pc2->m_r, nlen);
-            dda_line_interpolator<14> g(pc1->m_g, pc2->m_g, nlen);
-            dda_line_interpolator<14> b(pc1->m_b, pc2->m_b, nlen);
-            dda_line_interpolator<14> a(pc1->m_a, pc2->m_a, nlen);
-
-            // Calculate the starting point of the gradient with subpixel 
-            // accuracy and correct (roll back) the interpolators.
-            // This operation will also clip the beginning of the span
-            // if necessary.
-            //-------------------------
-            int start = pc1->m_x - (x << subpixel_shift);
-            r    -= start; 
-            g    -= start; 
-            b    -= start; 
-            a    -= start;
-            nlen += start;
-
-            int vr, vg, vb, va;
-            enum lim_e { lim = color_type::base_mask };
-
-            // Beginning part of the span. Since we rolled back the 
-            // interpolators, the color values may have overflow.
-            // So that, we render the beginning part with checking 
-            // for overflow. It lasts until "start" is positive;
-            // typically it's 1-2 pixels, but may be more in some cases.
-            //-------------------------
-            while(len && start > 0)
-            {
-                vr = r.y();
-                vg = g.y();
-                vb = b.y();
-                va = a.y();
-                if(vr < 0) vr = 0; if(vr > lim) vr = lim;
-                if(vg < 0) vg = 0; if(vg > lim) vg = lim;
-                if(vb < 0) vb = 0; if(vb > lim) vb = lim;
-                if(va < 0) va = 0; if(va > lim) va = lim;
-                span->r = (value_type)vr;
-                span->g = (value_type)vg;
-                span->b = (value_type)vb;
-                span->a = (value_type)va;
-                r     += subpixel_scale; 
-                g     += subpixel_scale; 
-                b     += subpixel_scale; 
-                a     += subpixel_scale;
-                nlen  -= subpixel_scale;
-                start -= subpixel_scale;
-                ++span;
-                --len;
-            }
-
-            // Middle part, no checking for overflow.
-            // Actual spans can be longer than the calculated length
-            // because of anti-aliasing, thus, the interpolators can 
-            // overflow. But while "nlen" is positive we are safe.
-            //-------------------------
-            while(len && nlen > 0)
-            {
-                span->r = (value_type)r.y();
-                span->g = (value_type)g.y();
-                span->b = (value_type)b.y();
-                span->a = (value_type)a.y();
-                r    += subpixel_scale; 
-                g    += subpixel_scale; 
-                b    += subpixel_scale; 
-                a    += subpixel_scale;
-                nlen -= subpixel_scale;
-                ++span;
-                --len;
-            }
-
-            // Ending part; checking for overflow.
-            // Typically it's 1-2 pixels, but may be more in some cases.
-            //-------------------------
-            while(len)
-            {
-                vr = r.y();
-                vg = g.y();
-                vb = b.y();
-                va = a.y();
-                if(vr < 0) vr = 0; if(vr > lim) vr = lim;
-                if(vg < 0) vg = 0; if(vg > lim) vg = lim;
-                if(vb < 0) vb = 0; if(vb > lim) vb = lim;
-                if(va < 0) va = 0; if(va > lim) va = lim;
-                span->r = (value_type)vr;
-                span->g = (value_type)vg;
-                span->b = (value_type)vb;
-                span->a = (value_type)va;
-                r += subpixel_scale; 
-                g += subpixel_scale; 
-                b += subpixel_scale; 
-                a += subpixel_scale;
-                ++span;
-                --len;
-            }
-        }
-
-    private:
-        bool      m_swap;
-        int       m_y2;
-        rgba_calc m_rgba1;
-        rgba_calc m_rgba2;
-        rgba_calc m_rgba3;
-    };
-
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_gradient.h b/xs/src/agg/agg_span_gradient.h
deleted file mode 100644
index 58b506dcf..000000000
--- a/xs/src/agg/agg_span_gradient.h
+++ /dev/null
@@ -1,377 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_GRADIENT_INCLUDED
-#define AGG_SPAN_GRADIENT_INCLUDED
-
-#include <math.h>
-#include <stdlib.h>
-#include <string.h>
-#include "agg_basics.h"
-#include "agg_math.h"
-#include "agg_array.h"
-
-
-namespace agg
-{
-
-    enum gradient_subpixel_scale_e
-    {
-        gradient_subpixel_shift = 4,                              //-----gradient_subpixel_shift
-        gradient_subpixel_scale = 1 << gradient_subpixel_shift,   //-----gradient_subpixel_scale
-        gradient_subpixel_mask  = gradient_subpixel_scale - 1     //-----gradient_subpixel_mask
-    };
-
-
-
-    //==========================================================span_gradient
-    template<class ColorT,
-             class Interpolator,
-             class GradientF, 
-             class ColorF>
-    class span_gradient
-    {
-    public:
-        typedef Interpolator interpolator_type;
-        typedef ColorT color_type;
-
-        enum downscale_shift_e
-        {
-            downscale_shift = interpolator_type::subpixel_shift - 
-                              gradient_subpixel_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_gradient() {}
-
-        //--------------------------------------------------------------------
-        span_gradient(interpolator_type& inter,
-                      GradientF& gradient_function,
-                      ColorF& color_function,
-                      double d1, double d2) : 
-            m_interpolator(&inter),
-            m_gradient_function(&gradient_function),
-            m_color_function(&color_function),
-            m_d1(iround(d1 * gradient_subpixel_scale)),
-            m_d2(iround(d2 * gradient_subpixel_scale))
-        {}
-
-        //--------------------------------------------------------------------
-        interpolator_type& interpolator() { return *m_interpolator; }
-        const GradientF& gradient_function() const { return *m_gradient_function; }
-        const ColorF& color_function() const { return *m_color_function; }
-        double d1() const { return double(m_d1) / gradient_subpixel_scale; }
-        double d2() const { return double(m_d2) / gradient_subpixel_scale; }
-
-        //--------------------------------------------------------------------
-        void interpolator(interpolator_type& i) { m_interpolator = &i; }
-        void gradient_function(GradientF& gf) { m_gradient_function = &gf; }
-        void color_function(ColorF& cf) { m_color_function = &cf; }
-        void d1(double v) { m_d1 = iround(v * gradient_subpixel_scale); }
-        void d2(double v) { m_d2 = iround(v * gradient_subpixel_scale); }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {   
-            int dd = m_d2 - m_d1;
-            if(dd < 1) dd = 1;
-            m_interpolator->begin(x+0.5, y+0.5, len);
-            do
-            {
-                m_interpolator->coordinates(&x, &y);
-                int d = m_gradient_function->calculate(x >> downscale_shift, 
-                                                       y >> downscale_shift, m_d2);
-                d = ((d - m_d1) * (int)m_color_function->size()) / dd;
-                if(d < 0) d = 0;
-                if(d >= (int)m_color_function->size()) d = m_color_function->size() - 1;
-                *span++ = (*m_color_function)[d];
-                ++(*m_interpolator);
-            }
-            while(--len);
-        }
-
-    private:
-        interpolator_type* m_interpolator;
-        GradientF*         m_gradient_function;
-        ColorF*            m_color_function;
-        int                m_d1;
-        int                m_d2;
-    };
-
-
-
-
-    //=====================================================gradient_linear_color
-    template<class ColorT> 
-    struct gradient_linear_color
-    {
-        typedef ColorT color_type;
-
-        gradient_linear_color() {}
-        gradient_linear_color(const color_type& c1, const color_type& c2, 
-                              unsigned size = 256) :
-            m_c1(c1), m_c2(c2), m_size(size)
-				// VFALCO 4/28/09
-				,m_mult(1/(double(size)-1))
-				// VFALCO
-			{}
-
-        unsigned size() const { return m_size; }
-        color_type operator [] (unsigned v) const 
-        {
-			// VFALCO 4/28/09 
-            //return m_c1.gradient(m_c2, double(v) / double(m_size - 1));
-            return m_c1.gradient(m_c2, double(v) * m_mult );
-			// VFALCO
-        }
-
-        void colors(const color_type& c1, const color_type& c2, unsigned size = 256)
-        {
-            m_c1 = c1;
-            m_c2 = c2;
-            m_size = size;
-			// VFALCO 4/28/09
-			m_mult=1/(double(size)-1);
-			// VFALCO
-        }
-
-        color_type m_c1;
-        color_type m_c2;
-        unsigned m_size;
-		// VFALCO 4/28/09
-		double m_mult;
-		// VFALCO
-    };
-
-
-
-
-
-
-    //==========================================================gradient_circle
-    class gradient_circle
-    {
-        // Actually the same as radial. Just for compatibility
-    public:
-        static AGG_INLINE int calculate(int x, int y, int)
-        {
-            return int(fast_sqrt(x*x + y*y));
-        }
-    };
-
-
-    //==========================================================gradient_radial
-    class gradient_radial
-    {
-    public:
-        static AGG_INLINE int calculate(int x, int y, int)
-        {
-            return int(fast_sqrt(x*x + y*y));
-        }
-    };
-
-    //========================================================gradient_radial_d
-    class gradient_radial_d
-    {
-    public:
-        static AGG_INLINE int calculate(int x, int y, int)
-        {
-            return uround(sqrt(double(x)*double(x) + double(y)*double(y)));
-        }
-    };
-
-    //====================================================gradient_radial_focus
-    class gradient_radial_focus
-    {
-    public:
-        //---------------------------------------------------------------------
-        gradient_radial_focus() : 
-            m_r(100 * gradient_subpixel_scale), 
-            m_fx(0), 
-            m_fy(0)
-        {
-            update_values();
-        }
-
-        //---------------------------------------------------------------------
-        gradient_radial_focus(double r, double fx, double fy) : 
-            m_r (iround(r  * gradient_subpixel_scale)), 
-            m_fx(iround(fx * gradient_subpixel_scale)), 
-            m_fy(iround(fy * gradient_subpixel_scale))
-        {
-            update_values();
-        }
-
-        //---------------------------------------------------------------------
-        void init(double r, double fx, double fy)
-        {
-            m_r  = iround(r  * gradient_subpixel_scale);
-            m_fx = iround(fx * gradient_subpixel_scale);
-            m_fy = iround(fy * gradient_subpixel_scale);
-            update_values();
-        }
-
-        //---------------------------------------------------------------------
-        double radius()  const { return double(m_r)  / gradient_subpixel_scale; }
-        double focus_x() const { return double(m_fx) / gradient_subpixel_scale; }
-        double focus_y() const { return double(m_fy) / gradient_subpixel_scale; }
-
-        //---------------------------------------------------------------------
-        int calculate(int x, int y, int) const
-        {
-            double dx = x - m_fx;
-            double dy = y - m_fy;
-            double d2 = dx * m_fy - dy * m_fx;
-            double d3 = m_r2 * (dx * dx + dy * dy) - d2 * d2;
-            return iround((dx * m_fx + dy * m_fy + sqrt(fabs(d3))) * m_mul);
-        }
-
-    private:
-        //---------------------------------------------------------------------
-        void update_values()
-        {
-            // Calculate the invariant values. In case the focal center
-            // lies exactly on the gradient circle the divisor degenerates
-            // into zero. In this case we just move the focal center by
-            // one subpixel unit possibly in the direction to the origin (0,0)
-            // and calculate the values again.
-            //-------------------------
-            m_r2  = double(m_r)  * double(m_r);
-            m_fx2 = double(m_fx) * double(m_fx);
-            m_fy2 = double(m_fy) * double(m_fy);
-            double d = (m_r2 - (m_fx2 + m_fy2));
-            if(d == 0)
-            {
-                if(m_fx) { if(m_fx < 0) ++m_fx; else --m_fx; }
-                if(m_fy) { if(m_fy < 0) ++m_fy; else --m_fy; }
-                m_fx2 = double(m_fx) * double(m_fx);
-                m_fy2 = double(m_fy) * double(m_fy);
-                d = (m_r2 - (m_fx2 + m_fy2));
-            }
-            m_mul = m_r / d;
-        }
-
-        int    m_r;
-        int    m_fx;
-        int    m_fy;
-        double m_r2;
-        double m_fx2;
-        double m_fy2;
-        double m_mul;
-    };
-
-
-    //==============================================================gradient_x
-    class gradient_x
-    {
-    public:
-        static int calculate(int x, int, int) { return x; }
-    };
-
-
-    //==============================================================gradient_y
-    class gradient_y
-    {
-    public:
-        static int calculate(int, int y, int) { return y; }
-    };
-
-    //========================================================gradient_diamond
-    class gradient_diamond
-    {
-    public:
-        static AGG_INLINE int calculate(int x, int y, int) 
-        { 
-            int ax = abs(x);
-            int ay = abs(y);
-            return ax > ay ? ax : ay; 
-        }
-    };
-
-    //=============================================================gradient_xy
-    class gradient_xy
-    {
-    public:
-        static AGG_INLINE int calculate(int x, int y, int d) 
-        { 
-            return abs(x) * abs(y) / d; 
-        }
-    };
-
-    //========================================================gradient_sqrt_xy
-    class gradient_sqrt_xy
-    {
-    public:
-        static AGG_INLINE int calculate(int x, int y, int) 
-        { 
-            return fast_sqrt(abs(x) * abs(y)); 
-        }
-    };
-
-    //==========================================================gradient_conic
-    class gradient_conic
-    {
-    public:
-        static AGG_INLINE int calculate(int x, int y, int d) 
-        { 
-            return uround(fabs(atan2(double(y), double(x))) * double(d) / pi);
-        }
-    };
-
-    //=================================================gradient_repeat_adaptor
-    template<class GradientF> class gradient_repeat_adaptor
-    {
-    public:
-        gradient_repeat_adaptor(const GradientF& gradient) : 
-            m_gradient(&gradient) {}
-
-        AGG_INLINE int calculate(int x, int y, int d) const
-        {
-            int ret = m_gradient->calculate(x, y, d) % d;
-            if(ret < 0) ret += d;
-            return ret;
-        }
-
-    private:
-        const GradientF* m_gradient;
-    };
-
-    //================================================gradient_reflect_adaptor
-    template<class GradientF> class gradient_reflect_adaptor
-    {
-    public:
-        gradient_reflect_adaptor(const GradientF& gradient) : 
-            m_gradient(&gradient) {}
-
-        AGG_INLINE int calculate(int x, int y, int d) const
-        {
-            int d2 = d << 1;
-            int ret = m_gradient->calculate(x, y, d) % d2;
-            if(ret <  0) ret += d2;
-            if(ret >= d) ret  = d2 - ret;
-            return ret;
-        }
-
-    private:
-        const GradientF* m_gradient;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_gradient_alpha.h b/xs/src/agg/agg_span_gradient_alpha.h
deleted file mode 100644
index 2ec040e3b..000000000
--- a/xs/src/agg/agg_span_gradient_alpha.h
+++ /dev/null
@@ -1,126 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_GRADIENT_ALPHA_INCLUDED
-#define AGG_SPAN_GRADIENT_ALPHA_INCLUDED
-
-#include "agg_span_gradient.h"
-
-namespace agg
-{
-    //======================================================span_gradient_alpha
-    template<class ColorT, 
-             class Interpolator,
-             class GradientF, 
-             class AlphaF>
-    class span_gradient_alpha
-    {
-    public:
-        typedef Interpolator interpolator_type;
-        typedef ColorT color_type;
-        typedef typename color_type::value_type alpha_type;
-
-        enum downscale_shift_e
-        {
-            downscale_shift = interpolator_type::subpixel_shift - gradient_subpixel_shift
-        };
-
-
-        //--------------------------------------------------------------------
-        span_gradient_alpha() {}
-
-        //--------------------------------------------------------------------
-        span_gradient_alpha(interpolator_type& inter,
-                            GradientF& gradient_function,
-                            AlphaF& alpha_function,
-                            double d1, double d2) : 
-            m_interpolator(&inter),
-            m_gradient_function(&gradient_function),
-            m_alpha_function(&alpha_function),
-            m_d1(iround(d1 * gradient_subpixel_scale)),
-            m_d2(iround(d2 * gradient_subpixel_scale))
-        {}
-
-        //--------------------------------------------------------------------
-        interpolator_type& interpolator() { return *m_interpolator; }
-        const GradientF& gradient_function() const { return *m_gradient_function; }
-        const AlphaF& alpha_function() const { return *m_alpha_function; }
-        double d1() const { return double(m_d1) / gradient_subpixel_scale; }
-        double d2() const { return double(m_d2) / gradient_subpixel_scale; }
-
-        //--------------------------------------------------------------------
-        void interpolator(interpolator_type& i) { m_interpolator = &i; }
-        void gradient_function(const GradientF& gf) { m_gradient_function = &gf; }
-        void alpha_function(const AlphaF& af) { m_alpha_function = &af; }
-        void d1(double v) { m_d1 = iround(v * gradient_subpixel_scale); }
-        void d2(double v) { m_d2 = iround(v * gradient_subpixel_scale); }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {   
-            int dd = m_d2 - m_d1;
-            if(dd < 1) dd = 1;
-            m_interpolator->begin(x+0.5, y+0.5, len);
-            do
-            {
-                m_interpolator->coordinates(&x, &y);
-                int d = m_gradient_function->calculate(x >> downscale_shift, 
-                                                       y >> downscale_shift, m_d2);
-                d = ((d - m_d1) * (int)m_alpha_function->size()) / dd;
-                if(d < 0) d = 0;
-                if(d >= (int)m_alpha_function->size()) d = m_alpha_function->size() - 1;
-                span->a = (*m_alpha_function)[d];
-                ++span;
-                ++(*m_interpolator);
-            }
-            while(--len);
-        }
-
-    private:
-        interpolator_type* m_interpolator;
-        GradientF*         m_gradient_function;
-        AlphaF*            m_alpha_function;
-        int                m_d1;
-        int                m_d2;
-    };
-
-
-    //=======================================================gradient_alpha_x
-    template<class ColorT> struct gradient_alpha_x
-    {
-        typedef typename ColorT::value_type alpha_type;
-        alpha_type operator [] (alpha_type x) const { return x; }
-    };
-
-    //====================================================gradient_alpha_x_u8
-    struct gradient_alpha_x_u8
-    {
-        typedef int8u alpha_type;
-        alpha_type operator [] (alpha_type x) const { return x; }
-    };
-
-    //==========================================gradient_alpha_one_munus_x_u8
-    struct gradient_alpha_one_munus_x_u8
-    {
-        typedef int8u alpha_type;
-        alpha_type operator [] (alpha_type x) const { return 255-x; }
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_gradient_contour.h b/xs/src/agg/agg_span_gradient_contour.h
deleted file mode 100644
index a1c4ca377..000000000
--- a/xs/src/agg/agg_span_gradient_contour.h
+++ /dev/null
@@ -1,362 +0,0 @@
-//----------------------------------------------------------------------------
-// AGG Contribution Pack - Gradients 1 (AGG CP - Gradients 1)
-// http://milan.marusinec.sk/aggcp
-//
-// For Anti-Grain Geometry - Version 2.4 
-// http://www.antigrain.org
-//
-// Contribution Created By:
-//  Milan Marusinec alias Milano
-//  milan@marusinec.sk
-//  Copyright (c) 2007-2008
-//
-// Permission to copy, use, modify, sell and distribute this software
-// is granted provided this copyright notice appears in all copies.
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-// [History] -----------------------------------------------------------------
-//
-// 02.02.2008-Milano: Ported from Object Pascal code of AggPas
-//
-#ifndef AGG_SPAN_GRADIENT_CONTOUR_INCLUDED
-#define AGG_SPAN_GRADIENT_CONTOUR_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_trans_affine.h"
-#include "agg_path_storage.h"
-#include "agg_pixfmt_gray.h"
-#include "agg_conv_transform.h"
-#include "agg_conv_curve.h"
-#include "agg_bounding_rect.h"
-#include "agg_renderer_base.h"
-#include "agg_renderer_primitives.h"
-#include "agg_rasterizer_outline.h"
-#include "agg_span_gradient.h"
-
-#include <float.h>
-
-namespace agg
-{
-
-	//==========================================================gradient_contour
-	class gradient_contour
-	{
-	private:
-		int8u* m_buffer;
-		int	   m_width;
-		int    m_height;
-		int    m_frame;
-
-		double m_d1;
-		double m_d2; 
-
-	public:
-		gradient_contour() :
-			m_buffer(NULL),
-			m_width(0),
-			m_height(0),
-			m_frame(10),
-			m_d1(0),
-			m_d2(100)
-		{
-		}
-
-		gradient_contour(double d1, double d2) :
-			m_buffer(NULL),
-			m_width(0),
-			m_height(0),
-			m_frame(10),
-			m_d1(d1),
-			m_d2(d2)
-		{
-		}
-
-		~gradient_contour()
-		{
-			if (m_buffer)
-			{
-				delete [] m_buffer;
-			}
-		}
-
-		int8u* contour_create(path_storage* ps );
-
-		int    contour_width() { return m_width; }
-		int    contour_height() { return m_height; }
-
-		void   d1(double d ) { m_d1 = d; }
-		void   d2(double d ) { m_d2 = d; }
-
-		void   frame(int f ) { m_frame = f; }
-		int    frame() { return m_frame; }
-		
-		int calculate(int x, int y, int d) const
-		{
-			if (m_buffer)
-			{
-				int px = x >> agg::gradient_subpixel_shift;
-				int py = y >> agg::gradient_subpixel_shift;
-
-				px %= m_width;
-
-				if (px < 0)
-				{
-					px += m_width;
-				}
-
-				py %= m_height;
-
-				if (py < 0 )
-				{
-					py += m_height;
-				}
-
-				return iround(m_buffer[py * m_width + px ] * (m_d2 / 256 ) + m_d1 ) << gradient_subpixel_shift;
-
-			}
-			else
-			{
-				return 0;
-			}
-		}
-
-	};
-
-	static AGG_INLINE int square(int x ) { return x * x; }
-
-	// DT algorithm by: Pedro Felzenszwalb
-	void dt(float* spanf, float* spang, float* spanr, int* spann ,int length )
-	{
-		int k = 0;
-		float s;
-
-		spann[0 ] = 0;
-		spang[0 ] = -FLT_MAX;
-		spang[1 ] = FLT_MAX;
-
-		for (int q = 1; q <= length - 1; q++)
-		{
-			s = ((spanf[q ] + square(q ) ) - (spanf[spann[k ] ] + square(spann[k ] ) ) ) / (2 * q - 2 * spann[k ] );
-
-			while (s <= spang[k ])
-			{
-				k--;
-				s = ((spanf[q ] + square(q ) ) - (spanf[spann[k ] ] + square(spann[k ] ) ) ) / (2 * q - 2 * spann[k ] );
-			}
-
-			k++;
-			spann[k ] = q;
-			spang[k ] = s;
-			spang[k + 1 ] = FLT_MAX;
-
-		}
-
-		k = 0;
-
-		for (int q = 0; q <= length - 1; q++)
-		{
-			while (spang[k + 1 ] < q )
-			{
-				k++;
-			}
-
-			spanr[q ] = square(q - spann[k ] ) + spanf[spann[k ] ];
-		}
-	}
-
-	// DT algorithm by: Pedro Felzenszwalb
-	int8u* gradient_contour::contour_create(path_storage* ps )
-	{
-		int8u* result = NULL;
-
-		if (ps)
-		{
-		   // I. Render Black And White NonAA Stroke of the Path
-		   // Path Bounding Box + Some Frame Space Around [configurable]
-			agg::conv_curve<agg::path_storage> conv(*ps);
-
-			double x1, y1, x2, y2;
-
-			if (agg::bounding_rect_single(conv ,0 ,&x1 ,&y1 ,&x2 ,&y2 ))
-			{
-			   // Create BW Rendering Surface
-				int width  = int(ceil(x2 - x1 ) ) + m_frame * 2 + 1;
-				int height = int(ceil(y2 - y1 ) ) + m_frame * 2 + 1;
-
-				int8u* buffer = new int8u[width * height];
-
-				if (buffer)
-				{
-					memset(buffer ,255 ,width * height );
-
-				   // Setup VG Engine & Render
-					agg::rendering_buffer rb;
-					rb.attach(buffer ,width ,height ,width );
-					
-					agg::pixfmt_gray8 pf(rb);
-					agg::renderer_base<agg::pixfmt_gray8> renb(pf );
-
-					agg::renderer_primitives<agg::renderer_base<agg::pixfmt_gray8> > prim(renb );
-					agg::rasterizer_outline<renderer_primitives<agg::renderer_base<agg::pixfmt_gray8> > > ras(prim );
-
-					agg::trans_affine mtx;
-					mtx *= agg::trans_affine_translation(-x1 + m_frame, -y1 + m_frame );
-
-					agg::conv_transform<agg::conv_curve<agg::path_storage> > trans(conv ,mtx );
-
-					prim.line_color(agg::rgba8(0 ,0 ,0 ,255 ) );
-					ras.add_path(trans );
-
-				   // II. Distance Transform
-				   // Create Float Buffer + 0 vs infinity assignment
-					float* image = new float[width * height];
-
-					if (image)
-					{
-						for (int y = 0, l = 0; y < height; y++ ) 
-						{
-							for (int x = 0; x < width; x++, l++ ) 
-							{
-								if (buffer[l ] == 0)
-								{
-									image[l ] = 0.0;
-								}
-								else
-								{
-									image[l ] = FLT_MAX;
-								}
-							}
-													
-						}
-
-					   // DT of 2d
-					   // SubBuff<float> max width,height
-						int length = width;
-
-						if (height > length)
-						{
-							length = height;
-						}
-
-						float* spanf = new float[length];
-						float* spang = new float[length + 1];
-						float* spanr = new float[length];
-						int* spann = new int[length];
-
-						if ((spanf) && (spang) && (spanr) && (spann))
-						{
-						   // Transform along columns
-							for (int x = 0; x < width; x++ ) 
-							{
-								for (int y = 0; y < height; y++ ) 
-								{
-									spanf[y] = image[y * width + x];
-								}
-
-							   // DT of 1d
-								dt(spanf ,spang ,spanr ,spann ,height );
-
-								for (int y = 0; y < height; y++ ) 
-								{
-									image[y * width + x] = spanr[y];
-								}
-							}
-
-						   // Transform along rows
-							for (int y = 0; y < height; y++ ) 
-							{
-								for (int x = 0; x < width; x++ ) 
-								{
-									spanf[x] = image[y * width + x];
-								}
-
-							   // DT of 1d
-								dt(spanf ,spang ,spanr ,spann ,width );
-
-								for (int x = 0; x < width; x++ ) 
-								{
-									image[y * width + x] = spanr[x];
-								}
-							}
-
-						   // Take Square Roots, Min & Max
-							float min = sqrt(image[0] );
-							float max = min;
-
-							for (int y = 0, l = 0; y < height; y++ ) 
-							{
-								for (int x = 0; x < width; x++, l++ ) 
-								{
-									image[l] = sqrt(image[l]);
-
-									if (min > image[l])
-									{
-										min = image[l];
-									}
-
-									if (max < image[l])
-									{
-										max = image[l];
-									}
-
-								}
-							}
-
-						   // III. Convert To Grayscale
-							if (min == max)
-							{
-								memset(buffer ,0 ,width * height );
-							}
-							else
-							{
-								float scale = 255 / (max - min );
-
-								for (int y = 0, l = 0; y < height; y++ ) 
-								{
-									for (int x = 0; x < width; x++ ,l++ ) 
-									{
-										buffer[l] = int8u(int((image[l] - min ) * scale ));
-									}
-								}
-							}
-
-						   // OK
-							if (m_buffer)
-							{
-								delete [] m_buffer;
-							}
-
-							m_buffer = buffer;
-							m_width  = width;
-							m_height = height;
-
-							buffer = NULL;
-							result = m_buffer;
-
-						}
-	
-						if (spanf) { delete [] spanf; }
-						if (spang) { delete [] spang; }
-						if (spanr) { delete [] spanr; }
-						if (spann) { delete [] spann; }
-
-						delete [] image;
-
-					}
-				}
-
-				if (buffer)
-				{
-					delete [] buffer;
-				}
-
-			}
-
-		}
-		return result;
-	}
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_gradient_image.h b/xs/src/agg/agg_span_gradient_image.h
deleted file mode 100644
index c99eaca16..000000000
--- a/xs/src/agg/agg_span_gradient_image.h
+++ /dev/null
@@ -1,188 +0,0 @@
-//----------------------------------------------------------------------------
-// AGG Contribution Pack - Gradients 1 (AGG CP - Gradients 1)
-// http://milan.marusinec.sk/aggcp
-//
-// For Anti-Grain Geometry - Version 2.4 
-// http://www.antigrain.org
-//
-// Contribution Created By:
-//  Milan Marusinec alias Milano
-//  milan@marusinec.sk
-//  Copyright (c) 2007-2008
-//
-// Permission to copy, use, modify, sell and distribute this software
-// is granted provided this copyright notice appears in all copies.
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-// [History] -----------------------------------------------------------------
-//
-// 03.02.2008-Milano: Ported from Object Pascal code of AggPas
-//
-#ifndef AGG_SPAN_GRADIENT_IMAGE_INCLUDED
-#define AGG_SPAN_GRADIENT_IMAGE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_span_gradient.h"
-#include "agg_color_rgba.h"
-#include "agg_rendering_buffer.h"
-#include "agg_pixfmt_rgba.h"
-
-namespace agg
-{
-
-	//==========================================================one_color_function
-	template<class ColorT> class one_color_function
-	{
-	public:
-		typedef ColorT color_type;
-
-		color_type m_color;
-
-		one_color_function() :
-			m_color()
-		{
-		}
-
-		static unsigned size() { return 1; }
-
-		const color_type& operator [] (unsigned i) const 
-		{
-			return m_color;
-		}
-
-		color_type* operator [] (unsigned i)
-		{
-			return &m_color;
-		}	        
-	};
-
-	//==========================================================gradient_image
-	template<class ColorT> class gradient_image
-	{
-	private:
-		//------------ fields
-		typedef ColorT color_type;
-		typedef agg::pixfmt_rgba32 pixfmt_type;
-
-		agg::rgba8* m_buffer;
-
-		int m_alocdx;
-		int m_alocdy;
-		int m_width;
-		int m_height;
-
-		color_type* m_color;
-
-		one_color_function<color_type> m_color_function;
-
-	public:
-		gradient_image() :
-			m_color_function(),
-			m_buffer(NULL),
-			m_alocdx(0),
-			m_alocdy(0),
-			m_width(0),
-			m_height(0)
-		{
-			m_color = m_color_function[0 ];
-		}
-
-		~gradient_image()
-		{
-			if (m_buffer) { delete [] m_buffer; }
-		}
-
-		void* image_create(int width, int height )
-		{
-			void* result = NULL;
-
-			if (width > m_alocdx || height > m_alocdy)
-			{
-				if (m_buffer) { delete [] m_buffer; }
-
-				m_buffer = NULL;
-				m_buffer = new agg::rgba8[width * height];
-
-				if (m_buffer)
-				{
-					m_alocdx = width;
-					m_alocdy = height;
-				}
-				else
-				{
-					m_alocdx = 0;
-					m_alocdy = 0;
-				};
-			};
-
-			if (m_buffer)
-			{
-				m_width  = width;
-				m_height = height;
-
-				for (int rows = 0; rows < height; rows++)
-				{
-					agg::rgba8* row = &m_buffer[rows * m_alocdx ];
-					memset(row ,0 ,m_width * 4 );
-				};
-
-				result = m_buffer;
-			};
-			return result;
-		}
-
-		void* image_buffer() { return m_buffer; }
-		int   image_width()  { return m_width; }
-		int   image_height() { return m_height; }
-		int   image_stride() { return m_alocdx * 4; }
-
-		int calculate(int x, int y, int d) const
-		{
-			if (m_buffer)
-			{
-				int px = x >> agg::gradient_subpixel_shift;
-				int py = y >> agg::gradient_subpixel_shift;
-
-				px %= m_width;
-
-				if (px < 0)
-				{
-					px += m_width;
-				}
-
-				py %= m_height;
-
-				if (py < 0 )
-				{
-					py += m_height;
-				}
-
-				rgba8* pixel = &m_buffer[py * m_alocdx + px ];
-
-				m_color->r = pixel->r;
-				m_color->g = pixel->g;
-				m_color->b = pixel->b;
-				m_color->a = pixel->a;
-
-			}
-			else
-			{
-				m_color->r = 0;
-				m_color->g = 0;
-				m_color->b = 0;
-				m_color->a = 0;
-			}
-			return 0;
-		}
-
-		const one_color_function<color_type>& color_function() const
-		{
-			return m_color_function;
-		}
-
-	};
-	
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_image_filter.h b/xs/src/agg/agg_span_image_filter.h
deleted file mode 100644
index 9d0a10a52..000000000
--- a/xs/src/agg/agg_span_image_filter.h
+++ /dev/null
@@ -1,247 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Image transformations with filtering. Span generator base class
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_SPAN_IMAGE_FILTER_INCLUDED
-#define AGG_SPAN_IMAGE_FILTER_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_image_filters.h"
-#include "agg_span_interpolator_linear.h"
-
-namespace agg
-{
-
-    //-------------------------------------------------------span_image_filter
-    template<class Source, class Interpolator> class span_image_filter
-    {
-    public:
-        typedef Source source_type;
-        typedef Interpolator interpolator_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter() {}
-        span_image_filter(source_type& src, 
-                          interpolator_type& interpolator,
-                          image_filter_lut* filter) : 
-            m_src(&src),
-            m_interpolator(&interpolator),
-            m_filter(filter),
-            m_dx_dbl(0.5),
-            m_dy_dbl(0.5),
-            m_dx_int(image_subpixel_scale / 2),
-            m_dy_int(image_subpixel_scale / 2)
-        {}
-        void attach(source_type& v) { m_src = &v; }
-
-        //--------------------------------------------------------------------
-               source_type& source()            { return *m_src; }
-        const  source_type& source()      const { return *m_src; }
-        const  image_filter_lut& filter() const { return *m_filter; }
-        int    filter_dx_int()            const { return m_dx_int; }
-        int    filter_dy_int()            const { return m_dy_int; }
-        double filter_dx_dbl()            const { return m_dx_dbl; }
-        double filter_dy_dbl()            const { return m_dy_dbl; }
-
-        //--------------------------------------------------------------------
-        void interpolator(interpolator_type& v)  { m_interpolator = &v; }
-        void filter(image_filter_lut& v)         { m_filter = &v; }
-        void filter_offset(double dx, double dy)
-        {
-            m_dx_dbl = dx;
-            m_dy_dbl = dy;
-            m_dx_int = iround(dx * image_subpixel_scale);
-            m_dy_int = iround(dy * image_subpixel_scale);
-        }
-        void filter_offset(double d) { filter_offset(d, d); }
-
-        //--------------------------------------------------------------------
-        interpolator_type& interpolator() { return *m_interpolator; }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-
-        //--------------------------------------------------------------------
-    private:
-        source_type*            m_src;
-        interpolator_type*      m_interpolator;
-        image_filter_lut*       m_filter;
-        double   m_dx_dbl;
-        double   m_dy_dbl;
-        unsigned m_dx_int;
-        unsigned m_dy_int;
-    };
-
-
-
-
-    //==============================================span_image_resample_affine
-    template<class Source> 
-    class span_image_resample_affine : 
-    public span_image_filter<Source, span_interpolator_linear<trans_affine> >
-    {
-    public:
-        typedef Source source_type;
-        typedef span_interpolator_linear<trans_affine> interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-
-        //--------------------------------------------------------------------
-        span_image_resample_affine() : 
-            m_scale_limit(200.0),
-            m_blur_x(1.0),
-            m_blur_y(1.0)
-        {}
-
-        //--------------------------------------------------------------------
-        span_image_resample_affine(source_type& src, 
-                                   interpolator_type& inter,
-                                   image_filter_lut& filter) :
-            base_type(src, inter, &filter),
-            m_scale_limit(200.0),
-            m_blur_x(1.0),
-            m_blur_y(1.0)
-        {}
-
-
-        //--------------------------------------------------------------------
-        int  scale_limit() const { return uround(m_scale_limit); }
-        void scale_limit(int v)  { m_scale_limit = v; }
-
-        //--------------------------------------------------------------------
-        double blur_x() const { return m_blur_x; }
-        double blur_y() const { return m_blur_y; }
-        void blur_x(double v) { m_blur_x = v; }
-        void blur_y(double v) { m_blur_y = v; }
-        void blur(double v) { m_blur_x = m_blur_y = v; }
-
-        //--------------------------------------------------------------------
-        void prepare() 
-        {
-            double scale_x;
-            double scale_y;
-
-            base_type::interpolator().transformer().scaling_abs(&scale_x, &scale_y);
-
-			double scale_xy = scale_x * scale_y;
-			if (scale_xy > m_scale_limit)
-            {
-				scale_x = scale_x * m_scale_limit / scale_xy;
-				scale_y = scale_y * m_scale_limit / scale_xy;
-            }
-
-            if(scale_x < 1) scale_x = 1;
-            if(scale_y < 1) scale_y = 1;
-
-            if(scale_x > m_scale_limit) scale_x = m_scale_limit;
-            if(scale_y > m_scale_limit) scale_y = m_scale_limit;
-
-            scale_x *= m_blur_x;
-            scale_y *= m_blur_y;
-
-            if(scale_x < 1) scale_x = 1;
-            if(scale_y < 1) scale_y = 1;
-
-            m_rx     = uround(    scale_x * double(image_subpixel_scale));
-            m_rx_inv = uround(1.0/scale_x * double(image_subpixel_scale));
-
-            m_ry     = uround(    scale_y * double(image_subpixel_scale));
-            m_ry_inv = uround(1.0/scale_y * double(image_subpixel_scale));
-        }
-
-    protected:
-        int m_rx;
-        int m_ry;
-        int m_rx_inv;
-        int m_ry_inv;
-
-    private:
-        double m_scale_limit;
-        double m_blur_x;
-        double m_blur_y;
-    };
-
-
-
-    //=====================================================span_image_resample
-    template<class Source, class Interpolator> 
-    class span_image_resample : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-
-        //--------------------------------------------------------------------
-        span_image_resample() : 
-            m_scale_limit(20),
-            m_blur_x(image_subpixel_scale),
-            m_blur_y(image_subpixel_scale)
-        {}
-
-        //--------------------------------------------------------------------
-        span_image_resample(source_type& src, 
-                            interpolator_type& inter,
-                            image_filter_lut& filter) :
-            base_type(src, inter, &filter),
-            m_scale_limit(20),
-            m_blur_x(image_subpixel_scale),
-            m_blur_y(image_subpixel_scale)
-        {}
-
-        //--------------------------------------------------------------------
-        int  scale_limit() const { return m_scale_limit; }
-        void scale_limit(int v)  { m_scale_limit = v; }
-
-        //--------------------------------------------------------------------
-        double blur_x() const { return double(m_blur_x) / double(image_subpixel_scale); }
-        double blur_y() const { return double(m_blur_y) / double(image_subpixel_scale); }
-        void blur_x(double v) { m_blur_x = uround(v * double(image_subpixel_scale)); }
-        void blur_y(double v) { m_blur_y = uround(v * double(image_subpixel_scale)); }
-        void blur(double v)   { m_blur_x = 
-                                m_blur_y = uround(v * double(image_subpixel_scale)); }
-
-    protected:
-        AGG_INLINE void adjust_scale(int* rx, int* ry)
-        {
-            if(*rx < image_subpixel_scale) *rx = image_subpixel_scale;
-            if(*ry < image_subpixel_scale) *ry = image_subpixel_scale;
-            if(*rx > image_subpixel_scale * m_scale_limit) 
-            {
-                *rx = image_subpixel_scale * m_scale_limit;
-            }
-            if(*ry > image_subpixel_scale * m_scale_limit) 
-            {
-                *ry = image_subpixel_scale * m_scale_limit;
-            }
-            *rx = (*rx * m_blur_x) >> image_subpixel_shift;
-            *ry = (*ry * m_blur_y) >> image_subpixel_shift;
-            if(*rx < image_subpixel_scale) *rx = image_subpixel_scale;
-            if(*ry < image_subpixel_scale) *ry = image_subpixel_scale;
-        }
-
-        int m_scale_limit;
-        int m_blur_x;
-        int m_blur_y;
-    };
-
-
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_image_filter_gray.h b/xs/src/agg/agg_span_image_filter_gray.h
deleted file mode 100644
index 4bc9c00be..000000000
--- a/xs/src/agg/agg_span_image_filter_gray.h
+++ /dev/null
@@ -1,723 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-#ifndef AGG_SPAN_IMAGE_FILTER_GRAY_INCLUDED
-#define AGG_SPAN_IMAGE_FILTER_GRAY_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_color_gray.h"
-#include "agg_span_image_filter.h"
-
-
-namespace agg
-{
-
-    //==============================================span_image_filter_gray_nn
-    template<class Source, class Interpolator> 
-    class span_image_filter_gray_nn : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_gray_nn() {}
-        span_image_filter_gray_nn(source_type& src, 
-                                  interpolator_type& inter) :
-            base_type(src, inter, 0) 
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-                span->v = *(const value_type*)
-                    base_type::source().span(x >> image_subpixel_shift, 
-                                             y >> image_subpixel_shift, 
-                                             1);
-                span->a = color_type::full_value();
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-
-    //=========================================span_image_filter_gray_bilinear
-    template<class Source, class Interpolator> 
-    class span_image_filter_gray_bilinear : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_gray_bilinear() {}
-        span_image_filter_gray_bilinear(source_type& src, 
-                                        interpolator_type& inter) :
-            base_type(src, inter, 0) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg;
-            const value_type *fg_ptr;
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                fg = 0;
-
-                x_hr &= image_subpixel_mask;
-                y_hr &= image_subpixel_mask;
-
-                fg_ptr = (const value_type*)base_type::source().span(x_lr, y_lr, 2);
-                fg    += *fg_ptr * (image_subpixel_scale - x_hr) * (image_subpixel_scale - y_hr);
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                fg    += *fg_ptr * x_hr * (image_subpixel_scale - y_hr);
-
-                fg_ptr = (const value_type*)base_type::source().next_y();
-                fg    += *fg_ptr * (image_subpixel_scale - x_hr) * y_hr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                fg    += *fg_ptr * x_hr * y_hr;
-
-                span->v = color_type::downshift(fg, image_subpixel_shift * 2);
-                span->a = color_type::full_value();
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-    //====================================span_image_filter_gray_bilinear_clip
-    template<class Source, class Interpolator> 
-    class span_image_filter_gray_bilinear_clip : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_gray_bilinear_clip() {}
-        span_image_filter_gray_bilinear_clip(source_type& src, 
-                                             const color_type& back_color,
-                                             interpolator_type& inter) :
-            base_type(src, inter, 0), 
-            m_back_color(back_color)
-        {}
-        const color_type& background_color() const { return m_back_color; }
-        void background_color(const color_type& v)   { m_back_color = v; }
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg;
-            long_type src_alpha;
-            value_type back_v = m_back_color.v;
-            value_type back_a = m_back_color.a;
-
-            const value_type *fg_ptr;
-
-            int maxx = base_type::source().width() - 1;
-            int maxy = base_type::source().height() - 1;
-
-            do
-            {
-                int x_hr;
-                int y_hr;
-                
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                if(x_lr >= 0    && y_lr >= 0 &&
-                   x_lr <  maxx && y_lr <  maxy) 
-                {
-                    fg = 0;
-
-                    x_hr &= image_subpixel_mask;
-                    y_hr &= image_subpixel_mask;
-                    fg_ptr = (const value_type*)base_type::source().row_ptr(y_lr) + x_lr;
-
-                    fg += *fg_ptr++ * (image_subpixel_scale - x_hr) * (image_subpixel_scale - y_hr);
-                    fg += *fg_ptr++ * (image_subpixel_scale - y_hr) * x_hr;
-
-                    ++y_lr;
-                    fg_ptr = (const value_type*)base_type::source().row_ptr(y_lr) + x_lr;
-
-                    fg += *fg_ptr++ * (image_subpixel_scale - x_hr) * y_hr;
-                    fg += *fg_ptr++ * x_hr * y_hr;
-
-                    fg = color_type::downshift(fg, image_subpixel_shift * 2);
-                    src_alpha = color_type::full_value();
-                }
-                else
-                {
-                    unsigned weight;
-                    if(x_lr < -1   || y_lr < -1 ||
-                       x_lr > maxx || y_lr > maxy)
-                    {
-                        fg        = back_v;
-                        src_alpha = back_a;
-                    }
-                    else
-                    {
-                        fg = src_alpha = 0;
-
-                        x_hr &= image_subpixel_mask;
-                        y_hr &= image_subpixel_mask;
-
-                        weight = (image_subpixel_scale - x_hr) * 
-                                 (image_subpixel_scale - y_hr);
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg += weight * 
-                                *((const value_type*)base_type::source().row_ptr(y_lr) + x_lr);
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg        += back_v * weight;
-                            src_alpha += back_a * weight;
-                        }
-
-                        x_lr++;
-
-                        weight = x_hr * (image_subpixel_scale - y_hr);
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg += weight * 
-                                *((const value_type*)base_type::source().row_ptr(y_lr) + x_lr);
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg        += back_v * weight;
-                            src_alpha += back_a * weight;
-                        }
-
-                        x_lr--;
-                        y_lr++;
-
-                        weight = (image_subpixel_scale - x_hr) * y_hr;
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg += weight * 
-                                *((const value_type*)base_type::source().row_ptr(y_lr) + x_lr);
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg        += back_v * weight;
-                            src_alpha += back_a * weight;
-                        }
-
-                        x_lr++;
-
-                        weight = x_hr * y_hr;
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg += weight * 
-                                *((const value_type*)base_type::source().row_ptr(y_lr) + x_lr);
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg        += back_v * weight;
-                            src_alpha += back_a * weight;
-                        }
-
-                        fg = color_type::downshift(fg, image_subpixel_shift * 2);
-                        src_alpha = color_type::downshift(src_alpha, image_subpixel_shift * 2);
-                    }
-                }
-
-                span->v = (value_type)fg;
-                span->a = (value_type)src_alpha;
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    private:
-        color_type m_back_color;
-    };
-
-
-
-    //==============================================span_image_filter_gray_2x2
-    template<class Source, class Interpolator> 
-    class span_image_filter_gray_2x2 : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_gray_2x2() {}
-        span_image_filter_gray_2x2(source_type& src, 
-                                   interpolator_type& inter,
-                                   image_filter_lut& filter) :
-            base_type(src, inter, &filter) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg;
-
-            const value_type *fg_ptr;
-            const int16* weight_array = base_type::filter().weight_array() + 
-                                        ((base_type::filter().diameter()/2 - 1) << 
-                                          image_subpixel_shift);
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                unsigned weight;
-                fg = 0;
-
-                x_hr &= image_subpixel_mask;
-                y_hr &= image_subpixel_mask;
-
-                fg_ptr = (const value_type*)base_type::source().span(x_lr, y_lr, 2);
-                weight = (weight_array[x_hr + image_subpixel_scale] * 
-                          weight_array[y_hr + image_subpixel_scale] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = (weight_array[x_hr] * 
-                          weight_array[y_hr + image_subpixel_scale] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_y();
-                weight = (weight_array[x_hr + image_subpixel_scale] * 
-                          weight_array[y_hr] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = (weight_array[x_hr] * 
-                          weight_array[y_hr] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg += weight * *fg_ptr;
-
-                fg >>= image_filter_shift;
-                if(fg > color_type::full_value()) fg = color_type::full_value();
-
-                span->v = (value_type)fg;
-                span->a = color_type::full_value();
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-
-    //==================================================span_image_filter_gray
-    template<class Source, class Interpolator> 
-    class span_image_filter_gray : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_gray() {}
-        span_image_filter_gray(source_type& src, 
-                               interpolator_type& inter,
-                               image_filter_lut& filter) :
-            base_type(src, inter, &filter) 
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg;
-            const value_type *fg_ptr;
-
-            unsigned     diameter     = base_type::filter().diameter();
-            int          start        = base_type::filter().start();
-            const int16* weight_array = base_type::filter().weight_array();
-
-            int x_count; 
-            int weight_y;
-
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-
-                x -= base_type::filter_dx_int();
-                y -= base_type::filter_dy_int();
-
-                int x_hr = x; 
-                int y_hr = y; 
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                fg = 0;
-
-                int x_fract = x_hr & image_subpixel_mask;
-                unsigned y_count = diameter;
-
-                y_hr = image_subpixel_mask - (y_hr & image_subpixel_mask);
-                fg_ptr = (const value_type*)base_type::source().span(x_lr + start, 
-                                                                     y_lr + start, 
-                                                                     diameter);
-                for(;;)
-                {
-                    x_count  = diameter;
-                    weight_y = weight_array[y_hr];
-                    x_hr = image_subpixel_mask - x_fract;
-                    for(;;)
-                    {
-                        fg += *fg_ptr * 
-                              ((weight_y * weight_array[x_hr] + 
-                                image_filter_scale / 2) >> 
-                                image_filter_shift);
-                        if(--x_count == 0) break;
-                        x_hr  += image_subpixel_scale;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-
-                    if(--y_count == 0) break;
-                    y_hr  += image_subpixel_scale;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg >>= image_filter_shift;
-                if(fg < 0) fg = 0;
-                if(fg > color_type::full_value()) fg = color_type::full_value();
-                span->v = (value_type)fg;
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //=========================================span_image_resample_gray_affine
-    template<class Source> 
-    class span_image_resample_gray_affine : 
-    public span_image_resample_affine<Source>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef span_image_resample_affine<source_type> base_type;
-        typedef typename base_type::interpolator_type interpolator_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        {
-            downscale_shift = image_filter_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_image_resample_gray_affine() {}
-        span_image_resample_gray_affine(source_type& src, 
-                                        interpolator_type& inter,
-                                        image_filter_lut& filter) :
-            base_type(src, inter, filter) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg;
-
-            int diameter     = base_type::filter().diameter();
-            int filter_scale = diameter << image_subpixel_shift;
-            int radius_x     = (diameter * base_type::m_rx) >> 1;
-            int radius_y     = (diameter * base_type::m_ry) >> 1;
-            int len_x_lr     = 
-                (diameter * base_type::m_rx + image_subpixel_mask) >> 
-                    image_subpixel_shift;
-
-            const int16* weight_array = base_type::filter().weight_array();
-
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-
-                x += base_type::filter_dx_int() - radius_x;
-                y += base_type::filter_dy_int() - radius_y;
-
-                fg = 0;
-
-                int y_lr = y >> image_subpixel_shift;
-                int y_hr = ((image_subpixel_mask - (y & image_subpixel_mask)) * 
-                                base_type::m_ry_inv) >> 
-                                    image_subpixel_shift;
-                int total_weight = 0;
-                int x_lr = x >> image_subpixel_shift;
-                int x_hr = ((image_subpixel_mask - (x & image_subpixel_mask)) * 
-                                base_type::m_rx_inv) >> 
-                                    image_subpixel_shift;
-
-                int x_hr2 = x_hr;
-                const value_type* fg_ptr = 
-                    (const value_type*)base_type::source().span(x_lr, y_lr, len_x_lr);
-                for(;;)
-                {
-                    int weight_y = weight_array[y_hr];
-                    x_hr = x_hr2;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     downscale_shift;
-
-                        fg += *fg_ptr * weight;
-                        total_weight += weight;
-                        x_hr  += base_type::m_rx_inv;
-                        if(x_hr >= filter_scale) break;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-                    y_hr += base_type::m_ry_inv;
-                    if(y_hr >= filter_scale) break;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg /= total_weight;
-                if(fg < 0) fg = 0;
-                if(fg > color_type::full_value()) fg = color_type::full_value();
-
-                span->v = (value_type)fg;
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-
-    //================================================span_image_resample_gray
-    template<class Source, class Interpolator>
-    class span_image_resample_gray : 
-    public span_image_resample<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_resample<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        {
-            downscale_shift = image_filter_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_image_resample_gray() {}
-        span_image_resample_gray(source_type& src, 
-                                 interpolator_type& inter,
-                                 image_filter_lut& filter) :
-            base_type(src, inter, filter)
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg;
-
-            int diameter = base_type::filter().diameter();
-            int filter_scale = diameter << image_subpixel_shift;
-
-            const int16* weight_array = base_type::filter().weight_array();
-            do
-            {
-                int rx;
-                int ry;
-                int rx_inv = image_subpixel_scale;
-                int ry_inv = image_subpixel_scale;
-                base_type::interpolator().coordinates(&x,  &y);
-                base_type::interpolator().local_scale(&rx, &ry);
-                base_type::adjust_scale(&rx, &ry);
-
-                rx_inv = image_subpixel_scale * image_subpixel_scale / rx;
-                ry_inv = image_subpixel_scale * image_subpixel_scale / ry;
-
-                int radius_x = (diameter * rx) >> 1;
-                int radius_y = (diameter * ry) >> 1;
-                int len_x_lr = 
-                    (diameter * rx + image_subpixel_mask) >> 
-                        image_subpixel_shift;
-
-                x += base_type::filter_dx_int() - radius_x;
-                y += base_type::filter_dy_int() - radius_y;
-
-                fg = 0;
-
-                int y_lr = y >> image_subpixel_shift;
-                int y_hr = ((image_subpixel_mask - (y & image_subpixel_mask)) * 
-                               ry_inv) >> 
-                                   image_subpixel_shift;
-                int total_weight = 0;
-                int x_lr = x >> image_subpixel_shift;
-                int x_hr = ((image_subpixel_mask - (x & image_subpixel_mask)) * 
-                               rx_inv) >> 
-                                   image_subpixel_shift;
-                int x_hr2 = x_hr;
-                const value_type* fg_ptr = 
-                    (const value_type*)base_type::source().span(x_lr, y_lr, len_x_lr);
-
-                for(;;)
-                {
-                    int weight_y = weight_array[y_hr];
-                    x_hr = x_hr2;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     downscale_shift;
-                        fg += *fg_ptr * weight;
-                        total_weight += weight;
-                        x_hr  += rx_inv;
-                        if(x_hr >= filter_scale) break;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-                    y_hr += ry_inv;
-                    if(y_hr >= filter_scale) break;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg /= total_weight;
-                if(fg < 0) fg = 0;
-                if(fg > color_type::full_value()) fg = color_type::full_value();
-
-                span->v = (value_type)fg;
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-}
-
-
-#endif
-
-
-
diff --git a/xs/src/agg/agg_span_image_filter_rgb.h b/xs/src/agg/agg_span_image_filter_rgb.h
deleted file mode 100644
index f78ae19c1..000000000
--- a/xs/src/agg/agg_span_image_filter_rgb.h
+++ /dev/null
@@ -1,861 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-#ifndef AGG_SPAN_IMAGE_FILTER_RGB_INCLUDED
-#define AGG_SPAN_IMAGE_FILTER_RGB_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_color_rgba.h"
-#include "agg_span_image_filter.h"
-
-
-namespace agg
-{
-
-    //===============================================span_image_filter_rgb_nn
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgb_nn : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgb_nn() {}
-        span_image_filter_rgb_nn(source_type& src, 
-                                 interpolator_type& inter) :
-            base_type(src, inter, 0) 
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-                const value_type* fg_ptr = (const value_type*)
-                    base_type::source().span(x >> image_subpixel_shift, 
-                                             y >> image_subpixel_shift, 
-                                             1);
-                span->r = fg_ptr[order_type::R];
-                span->g = fg_ptr[order_type::G];
-                span->b = fg_ptr[order_type::B];
-                span->a = color_type::full_value();
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //==========================================span_image_filter_rgb_bilinear
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgb_bilinear : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgb_bilinear() {}
-        span_image_filter_rgb_bilinear(source_type& src, 
-                                       interpolator_type& inter) :
-            base_type(src, inter, 0) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg[3];
-            const value_type *fg_ptr;
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                unsigned weight;
-
-                fg[0] = fg[1] = fg[2] = 0;
-
-                x_hr &= image_subpixel_mask;
-                y_hr &= image_subpixel_mask;
-
-                fg_ptr = (const value_type*)base_type::source().span(x_lr, y_lr, 2);
-                weight = (image_subpixel_scale - x_hr) * 
-                         (image_subpixel_scale - y_hr);
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = x_hr * (image_subpixel_scale - y_hr);
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_y();
-                weight = (image_subpixel_scale - x_hr) * y_hr;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = x_hr * y_hr;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                span->r = color_type::downshift(fg[order_type::R], image_subpixel_shift * 2);
-                span->g = color_type::downshift(fg[order_type::G], image_subpixel_shift * 2);
-                span->b = color_type::downshift(fg[order_type::B], image_subpixel_shift * 2);
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //=====================================span_image_filter_rgb_bilinear_clip
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgb_bilinear_clip : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgb_bilinear_clip() {}
-        span_image_filter_rgb_bilinear_clip(source_type& src, 
-                                            const color_type& back_color,
-                                            interpolator_type& inter) :
-            base_type(src, inter, 0),
-            m_back_color(back_color)
-        {}
-        const color_type& background_color() const { return m_back_color; }
-        void background_color(const color_type& v)   { m_back_color = v; }
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg[3];
-            long_type src_alpha;
-            value_type back_r = m_back_color.r;
-            value_type back_g = m_back_color.g;
-            value_type back_b = m_back_color.b;
-            value_type back_a = m_back_color.a;
-
-            const value_type *fg_ptr;
-
-            int maxx = base_type::source().width() - 1;
-            int maxy = base_type::source().height() - 1;
-
-            do
-            {
-                int x_hr;
-                int y_hr;
-                
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-                unsigned weight;
-
-                if(x_lr >= 0    && y_lr >= 0 &&
-                   x_lr <  maxx && y_lr <  maxy) 
-                {
-                    fg[0] = fg[1] = fg[2] = 0;
-
-                    x_hr &= image_subpixel_mask;
-                    y_hr &= image_subpixel_mask;
-
-                    fg_ptr = (const value_type*)
-                        base_type::source().row_ptr(y_lr) + x_lr + x_lr + x_lr;
-
-                    weight = (image_subpixel_scale - x_hr) * 
-                             (image_subpixel_scale - y_hr);
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-
-                    weight = x_hr * (image_subpixel_scale - y_hr);
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-
-                    ++y_lr;
-                    fg_ptr = (const value_type*)
-                        base_type::source().row_ptr(y_lr) + x_lr + x_lr + x_lr;
-
-                    weight = (image_subpixel_scale - x_hr) * y_hr;
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-
-                    weight = x_hr * y_hr;
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-
-                    fg[0] = color_type::downshift(fg[0], image_subpixel_shift * 2);
-                    fg[1] = color_type::downshift(fg[1], image_subpixel_shift * 2);
-                    fg[2] = color_type::downshift(fg[2], image_subpixel_shift * 2);
-                    src_alpha = color_type::full_value();
-                }
-                else
-                {
-                    if(x_lr < -1   || y_lr < -1 ||
-                       x_lr > maxx || y_lr > maxy)
-                    {
-                        fg[order_type::R] = back_r;
-                        fg[order_type::G] = back_g;
-                        fg[order_type::B] = back_b;
-                        src_alpha         = back_a;
-                    }
-                    else
-                    {
-                        fg[0] = fg[1] = fg[2] = src_alpha = 0;
-
-                        x_hr &= image_subpixel_mask;
-                        y_hr &= image_subpixel_mask;
-
-                        weight = (image_subpixel_scale - x_hr) * 
-                                 (image_subpixel_scale - y_hr);
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + x_lr + x_lr + x_lr;
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            src_alpha         += back_a * weight;
-                        }
-
-                        x_lr++;
-
-                        weight = x_hr * (image_subpixel_scale - y_hr);
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + x_lr + x_lr + x_lr;
-
-                            fg[0]     += weight * *fg_ptr++;
-                            fg[1]     += weight * *fg_ptr++;
-                            fg[2]     += weight * *fg_ptr++;
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            src_alpha         += back_a * weight;
-                        }
-
-                        x_lr--;
-                        y_lr++;
-
-                        weight = (image_subpixel_scale - x_hr) * y_hr;
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + x_lr + x_lr + x_lr;
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            src_alpha         += back_a * weight;
-                        }
-
-                        x_lr++;
-
-                        weight = x_hr * y_hr;
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + x_lr + x_lr + x_lr;
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            src_alpha += weight * color_type::full_value();
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            src_alpha         += back_a * weight;
-                        }
-
-                        fg[0] = color_type::downshift(fg[0], image_subpixel_shift * 2);
-                        fg[1] = color_type::downshift(fg[1], image_subpixel_shift * 2);
-                        fg[2] = color_type::downshift(fg[2], image_subpixel_shift * 2);
-                        src_alpha = color_type::downshift(src_alpha, image_subpixel_shift * 2);
-                    }
-                }
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = (value_type)src_alpha;
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    private:
-        color_type m_back_color;
-    };
-
-
-
-    //===============================================span_image_filter_rgb_2x2
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgb_2x2 : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgb_2x2() {}
-        span_image_filter_rgb_2x2(source_type& src, 
-                                  interpolator_type& inter,
-                                  image_filter_lut& filter) :
-            base_type(src, inter, &filter) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[3];
-
-            const value_type *fg_ptr;
-            const int16* weight_array = base_type::filter().weight_array() + 
-                                        ((base_type::filter().diameter()/2 - 1) << 
-                                          image_subpixel_shift);
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                unsigned weight;
-                fg[0] = fg[1] = fg[2] = 0;
-
-                x_hr &= image_subpixel_mask;
-                y_hr &= image_subpixel_mask;
-
-                fg_ptr = (const value_type*)base_type::source().span(x_lr, y_lr, 2);
-                weight = (weight_array[x_hr + image_subpixel_scale] * 
-                          weight_array[y_hr + image_subpixel_scale] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = (weight_array[x_hr] * 
-                          weight_array[y_hr + image_subpixel_scale] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_y();
-                weight = (weight_array[x_hr + image_subpixel_scale] * 
-                          weight_array[y_hr] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = (weight_array[x_hr] * 
-                          weight_array[y_hr] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr;
-
-                fg[0] = color_type::downshift(fg[0], image_filter_shift);
-                fg[1] = color_type::downshift(fg[1], image_filter_shift);
-                fg[2] = color_type::downshift(fg[2], image_filter_shift);
-
-                if(fg[order_type::R] > color_type::full_value()) fg[order_type::R] = color_type::full_value();
-                if(fg[order_type::G] > color_type::full_value()) fg[order_type::G] = color_type::full_value();
-                if(fg[order_type::B] > color_type::full_value()) fg[order_type::B] = color_type::full_value();
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //===================================================span_image_filter_rgb
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgb : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgb() {}
-        span_image_filter_rgb(source_type& src, 
-                              interpolator_type& inter,
-                              image_filter_lut& filter) :
-            base_type(src, inter, &filter) 
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[3];
-            const value_type *fg_ptr;
-
-            unsigned     diameter     = base_type::filter().diameter();
-            int          start        = base_type::filter().start();
-            const int16* weight_array = base_type::filter().weight_array();
-
-            int x_count; 
-            int weight_y;
-
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-
-                x -= base_type::filter_dx_int();
-                y -= base_type::filter_dy_int();
-
-                int x_hr = x; 
-                int y_hr = y; 
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                fg[0] = fg[1] = fg[2] = 0;
-
-                int x_fract = x_hr & image_subpixel_mask;
-                unsigned y_count = diameter;
-
-                y_hr = image_subpixel_mask - (y_hr & image_subpixel_mask);
-                fg_ptr = (const value_type*)base_type::source().span(x_lr + start, 
-                                                                     y_lr + start, 
-                                                                     diameter);
-                for(;;)
-                {
-                    x_count  = diameter;
-                    weight_y = weight_array[y_hr];
-                    x_hr = image_subpixel_mask - x_fract;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     image_filter_shift;
-
-                        fg[0] += weight * *fg_ptr++;
-                        fg[1] += weight * *fg_ptr++;
-                        fg[2] += weight * *fg_ptr;
-
-                        if(--x_count == 0) break;
-                        x_hr  += image_subpixel_scale;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-
-                    if(--y_count == 0) break;
-                    y_hr  += image_subpixel_scale;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg[0] = color_type::downshift(fg[0], image_filter_shift);
-                fg[1] = color_type::downshift(fg[1], image_filter_shift);
-                fg[2] = color_type::downshift(fg[2], image_filter_shift);
-
-                if(fg[0] < 0) fg[0] = 0;
-                if(fg[1] < 0) fg[1] = 0;
-                if(fg[2] < 0) fg[2] = 0;
-
-                if(fg[order_type::R] > color_type::full_value()) fg[order_type::R] = color_type::full_value();
-                if(fg[order_type::G] > color_type::full_value()) fg[order_type::G] = color_type::full_value();
-                if(fg[order_type::B] > color_type::full_value()) fg[order_type::B] = color_type::full_value();
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //==========================================span_image_resample_rgb_affine
-    template<class Source> 
-    class span_image_resample_rgb_affine : 
-    public span_image_resample_affine<Source>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef span_image_resample_affine<source_type> base_type;
-        typedef typename base_type::interpolator_type interpolator_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        {
-            downscale_shift = image_filter_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_image_resample_rgb_affine() {}
-        span_image_resample_rgb_affine(source_type& src, 
-                                       interpolator_type& inter,
-                                       image_filter_lut& filter) :
-            base_type(src, inter, filter) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[3];
-
-            int diameter     = base_type::filter().diameter();
-            int filter_scale = diameter << image_subpixel_shift;
-            int radius_x     = (diameter * base_type::m_rx) >> 1;
-            int radius_y     = (diameter * base_type::m_ry) >> 1;
-            int len_x_lr     = 
-                (diameter * base_type::m_rx + image_subpixel_mask) >> 
-                    image_subpixel_shift;
-
-            const int16* weight_array = base_type::filter().weight_array();
-
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-
-                x += base_type::filter_dx_int() - radius_x;
-                y += base_type::filter_dy_int() - radius_y;
-
-                fg[0] = fg[1] = fg[2] = 0;
-
-                int y_lr = y >> image_subpixel_shift;
-                int y_hr = ((image_subpixel_mask - (y & image_subpixel_mask)) * 
-                                base_type::m_ry_inv) >> 
-                                    image_subpixel_shift;
-                int total_weight = 0;
-                int x_lr = x >> image_subpixel_shift;
-                int x_hr = ((image_subpixel_mask - (x & image_subpixel_mask)) * 
-                                base_type::m_rx_inv) >> 
-                                    image_subpixel_shift;
-
-                int x_hr2 = x_hr;
-                const value_type* fg_ptr = 
-                    (const value_type*)base_type::source().span(x_lr, y_lr, len_x_lr);
-                for(;;)
-                {
-                    int weight_y = weight_array[y_hr];
-                    x_hr = x_hr2;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     downscale_shift;
-
-                        fg[0] += *fg_ptr++ * weight;
-                        fg[1] += *fg_ptr++ * weight;
-                        fg[2] += *fg_ptr   * weight;
-                        total_weight += weight;
-                        x_hr  += base_type::m_rx_inv;
-                        if(x_hr >= filter_scale) break;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-                    y_hr += base_type::m_ry_inv;
-                    if(y_hr >= filter_scale) break;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg[0] /= total_weight;
-                fg[1] /= total_weight;
-                fg[2] /= total_weight;
-
-                if(fg[0] < 0) fg[0] = 0;
-                if(fg[1] < 0) fg[1] = 0;
-                if(fg[2] < 0) fg[2] = 0;
-
-                if(fg[order_type::R] > color_type::full_value()) fg[order_type::R] = color_type::full_value();
-                if(fg[order_type::G] > color_type::full_value()) fg[order_type::G] = color_type::full_value();
-                if(fg[order_type::B] > color_type::full_value()) fg[order_type::B] = color_type::full_value();
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-
-    //=================================================span_image_resample_rgb
-    template<class Source, class Interpolator>
-    class span_image_resample_rgb : 
-    public span_image_resample<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_resample<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        {
-            downscale_shift = image_filter_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_image_resample_rgb() {}
-        span_image_resample_rgb(source_type& src, 
-                                interpolator_type& inter,
-                                image_filter_lut& filter) :
-            base_type(src, inter, filter)
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg[3];
-
-            int diameter = base_type::filter().diameter();
-            int filter_scale = diameter << image_subpixel_shift;
-
-            const int16* weight_array = base_type::filter().weight_array();
-            do
-            {
-                int rx;
-                int ry;
-                int rx_inv = image_subpixel_scale;
-                int ry_inv = image_subpixel_scale;
-                base_type::interpolator().coordinates(&x,  &y);
-                base_type::interpolator().local_scale(&rx, &ry);
-                base_type::adjust_scale(&rx, &ry);
-
-                rx_inv = image_subpixel_scale * image_subpixel_scale / rx;
-                ry_inv = image_subpixel_scale * image_subpixel_scale / ry;
-
-                int radius_x = (diameter * rx) >> 1;
-                int radius_y = (diameter * ry) >> 1;
-                int len_x_lr = 
-                    (diameter * rx + image_subpixel_mask) >> 
-                        image_subpixel_shift;
-
-                x += base_type::filter_dx_int() - radius_x;
-                y += base_type::filter_dy_int() - radius_y;
-
-                fg[0] = fg[1] = fg[2] = 0;
-
-                int y_lr = y >> image_subpixel_shift;
-                int y_hr = ((image_subpixel_mask - (y & image_subpixel_mask)) * 
-                               ry_inv) >> 
-                                   image_subpixel_shift;
-                int total_weight = 0;
-                int x_lr = x >> image_subpixel_shift;
-                int x_hr = ((image_subpixel_mask - (x & image_subpixel_mask)) * 
-                               rx_inv) >> 
-                                   image_subpixel_shift;
-                int x_hr2 = x_hr;
-                const value_type* fg_ptr = 
-                    (const value_type*)base_type::source().span(x_lr, y_lr, len_x_lr);
-
-                for(;;)
-                {
-                    int weight_y = weight_array[y_hr];
-                    x_hr = x_hr2;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     downscale_shift;
-                        fg[0] += *fg_ptr++ * weight;
-                        fg[1] += *fg_ptr++ * weight;
-                        fg[2] += *fg_ptr   * weight;
-                        total_weight += weight;
-                        x_hr  += rx_inv;
-                        if(x_hr >= filter_scale) break;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-                    y_hr += ry_inv;
-                    if(y_hr >= filter_scale) break;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg[0] /= total_weight;
-                fg[1] /= total_weight;
-                fg[2] /= total_weight;
-
-                if(fg[0] < 0) fg[0] = 0;
-                if(fg[1] < 0) fg[1] = 0;
-                if(fg[2] < 0) fg[2] = 0;
-
-                if(fg[order_type::R] > color_type::full_value()) fg[order_type::R] = color_type::full_value();
-                if(fg[order_type::G] > color_type::full_value()) fg[order_type::G] = color_type::full_value();
-                if(fg[order_type::B] > color_type::full_value()) fg[order_type::B] = color_type::full_value();
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = color_type::full_value();
-
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-}
-
-
-#endif
-
-
-
diff --git a/xs/src/agg/agg_span_image_filter_rgba.h b/xs/src/agg/agg_span_image_filter_rgba.h
deleted file mode 100644
index af7a1a2ef..000000000
--- a/xs/src/agg/agg_span_image_filter_rgba.h
+++ /dev/null
@@ -1,890 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-#ifndef AGG_SPAN_IMAGE_FILTER_RGBA_INCLUDED
-#define AGG_SPAN_IMAGE_FILTER_RGBA_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_color_rgba.h"
-#include "agg_span_image_filter.h"
-
-
-namespace agg
-{
-
-    //==============================================span_image_filter_rgba_nn
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgba_nn : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgba_nn() {}
-        span_image_filter_rgba_nn(source_type& src, 
-                                  interpolator_type& inter) :
-            base_type(src, inter, 0) 
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-                const value_type* fg_ptr = (const value_type*)
-                    base_type::source().span(x >> image_subpixel_shift, 
-                                             y >> image_subpixel_shift, 
-                                             1);
-                span->r = fg_ptr[order_type::R];
-                span->g = fg_ptr[order_type::G];
-                span->b = fg_ptr[order_type::B];
-                span->a = fg_ptr[order_type::A];
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //=========================================span_image_filter_rgba_bilinear
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgba_bilinear : 
-        public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgba_bilinear() {}
-        span_image_filter_rgba_bilinear(source_type& src, 
-                                        interpolator_type& inter) :
-            base_type(src, inter, 0) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[4];
-            const value_type *fg_ptr;
-
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                unsigned weight;
-
-                fg[0] = 
-                fg[1] = 
-                fg[2] = 
-                fg[3] = image_subpixel_scale * image_subpixel_scale / 2;
-
-                x_hr &= image_subpixel_mask;
-                y_hr &= image_subpixel_mask;
-
-                fg_ptr = (const value_type*)base_type::source().span(x_lr, y_lr, 2);
-                weight = (image_subpixel_scale - x_hr) * 
-                         (image_subpixel_scale - y_hr);
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = x_hr * (image_subpixel_scale - y_hr);
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_y();
-                weight = (image_subpixel_scale - x_hr) * y_hr;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = x_hr * y_hr;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                span->r = value_type(color_type::downshift(fg[order_type::R], image_subpixel_shift * 2));
-                span->g = value_type(color_type::downshift(fg[order_type::G], image_subpixel_shift * 2));
-                span->b = value_type(color_type::downshift(fg[order_type::B], image_subpixel_shift * 2));
-                span->a = value_type(color_type::downshift(fg[order_type::A], image_subpixel_shift * 2));
-
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-    //====================================span_image_filter_rgba_bilinear_clip
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgba_bilinear_clip : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgba_bilinear_clip() {}
-        span_image_filter_rgba_bilinear_clip(source_type& src, 
-                                             const color_type& back_color,
-                                             interpolator_type& inter) :
-            base_type(src, inter, 0),
-            m_back_color(back_color)
-        {}
-        const color_type& background_color() const { return m_back_color; }
-        void background_color(const color_type& v)   { m_back_color = v; }
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[4];
-            value_type back_r = m_back_color.r;
-            value_type back_g = m_back_color.g;
-            value_type back_b = m_back_color.b;
-            value_type back_a = m_back_color.a;
-
-            const value_type *fg_ptr;
-            int maxx = base_type::source().width() - 1;
-            int maxy = base_type::source().height() - 1;
-
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                unsigned weight;
-
-                if(x_lr >= 0    && y_lr >= 0 &&
-                   x_lr <  maxx && y_lr <  maxy) 
-                {
-                    fg[0] = fg[1] = fg[2] = fg[3] = 0;
-
-                    x_hr &= image_subpixel_mask;
-                    y_hr &= image_subpixel_mask;
-
-                    fg_ptr = (const value_type*)
-                        base_type::source().row_ptr(y_lr) + (x_lr << 2);
-
-                    weight = (image_subpixel_scale - x_hr) * 
-                             (image_subpixel_scale - y_hr);
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-                    fg[3] += weight * *fg_ptr++;
-
-                    weight = x_hr * (image_subpixel_scale - y_hr);
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-                    fg[3] += weight * *fg_ptr++;
-
-                    ++y_lr;
-                    fg_ptr = (const value_type*)
-                        base_type::source().row_ptr(y_lr) + (x_lr << 2);
-
-                    weight = (image_subpixel_scale - x_hr) * y_hr;
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-                    fg[3] += weight * *fg_ptr++;
-
-                    weight = x_hr * y_hr;
-                    fg[0] += weight * *fg_ptr++;
-                    fg[1] += weight * *fg_ptr++;
-                    fg[2] += weight * *fg_ptr++;
-                    fg[3] += weight * *fg_ptr++;
-
-                    fg[0] = color_type::downshift(fg[0], image_subpixel_shift * 2);
-                    fg[1] = color_type::downshift(fg[1], image_subpixel_shift * 2);
-                    fg[2] = color_type::downshift(fg[2], image_subpixel_shift * 2);
-                    fg[3] = color_type::downshift(fg[3], image_subpixel_shift * 2);
-                }
-                else
-                {
-                    if(x_lr < -1   || y_lr < -1 ||
-                       x_lr > maxx || y_lr > maxy)
-                    {
-                        fg[order_type::R] = back_r;
-                        fg[order_type::G] = back_g;
-                        fg[order_type::B] = back_b;
-                        fg[order_type::A] = back_a;
-                    }
-                    else
-                    {
-                        fg[0] = fg[1] = fg[2] = fg[3] = 0;
-
-                        x_hr &= image_subpixel_mask;
-                        y_hr &= image_subpixel_mask;
-
-                        weight = (image_subpixel_scale - x_hr) * 
-                                 (image_subpixel_scale - y_hr);
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + (x_lr << 2);
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            fg[3] += weight * *fg_ptr++;
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            fg[order_type::A] += back_a * weight;
-                        }
-
-                        x_lr++;
-
-                        weight = x_hr * (image_subpixel_scale - y_hr);
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + (x_lr << 2);
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            fg[3] += weight * *fg_ptr++;
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            fg[order_type::A] += back_a * weight;
-                        }
-
-                        x_lr--;
-                        y_lr++;
-
-                        weight = (image_subpixel_scale - x_hr) * y_hr;
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + (x_lr << 2);
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            fg[3] += weight * *fg_ptr++;
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            fg[order_type::A] += back_a * weight;
-                        }
-
-                        x_lr++;
-
-                        weight = x_hr * y_hr;
-                        if(x_lr >= 0    && y_lr >= 0 &&
-                           x_lr <= maxx && y_lr <= maxy)
-                        {
-                            fg_ptr = (const value_type*)
-                                base_type::source().row_ptr(y_lr) + (x_lr << 2);
-
-                            fg[0] += weight * *fg_ptr++;
-                            fg[1] += weight * *fg_ptr++;
-                            fg[2] += weight * *fg_ptr++;
-                            fg[3] += weight * *fg_ptr++;
-                        }
-                        else
-                        {
-                            fg[order_type::R] += back_r * weight;
-                            fg[order_type::G] += back_g * weight;
-                            fg[order_type::B] += back_b * weight;
-                            fg[order_type::A] += back_a * weight;
-                        }
-
-                        fg[0] = color_type::downshift(fg[0], image_subpixel_shift * 2);
-                        fg[1] = color_type::downshift(fg[1], image_subpixel_shift * 2);
-                        fg[2] = color_type::downshift(fg[2], image_subpixel_shift * 2);
-                        fg[3] = color_type::downshift(fg[3], image_subpixel_shift * 2);
-                    }
-                }
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = (value_type)fg[order_type::A];
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    private:
-        color_type m_back_color;
-    };
-
-
-    //==============================================span_image_filter_rgba_2x2
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgba_2x2 : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgba_2x2() {}
-        span_image_filter_rgba_2x2(source_type& src, 
-                                   interpolator_type& inter,
-                                   image_filter_lut& filter) :
-            base_type(src, inter, &filter) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[4];
-
-            const value_type *fg_ptr;
-            const int16* weight_array = base_type::filter().weight_array() + 
-                                        ((base_type::filter().diameter()/2 - 1) << 
-                                          image_subpixel_shift);
-
-            do
-            {
-                int x_hr;
-                int y_hr;
-
-                base_type::interpolator().coordinates(&x_hr, &y_hr);
-
-                x_hr -= base_type::filter_dx_int();
-                y_hr -= base_type::filter_dy_int();
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                unsigned weight;
-                fg[0] = fg[1] = fg[2] = fg[3] = 0;
-
-                x_hr &= image_subpixel_mask;
-                y_hr &= image_subpixel_mask;
-
-                fg_ptr = (const value_type*)base_type::source().span(x_lr, y_lr, 2);
-                weight = (weight_array[x_hr + image_subpixel_scale] * 
-                          weight_array[y_hr + image_subpixel_scale] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = (weight_array[x_hr] * 
-                          weight_array[y_hr + image_subpixel_scale] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_y();
-                weight = (weight_array[x_hr + image_subpixel_scale] * 
-                          weight_array[y_hr] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg_ptr = (const value_type*)base_type::source().next_x();
-                weight = (weight_array[x_hr] * 
-                          weight_array[y_hr] + 
-                          image_filter_scale / 2) >> 
-                          image_filter_shift;
-                fg[0] += weight * *fg_ptr++;
-                fg[1] += weight * *fg_ptr++;
-                fg[2] += weight * *fg_ptr++;
-                fg[3] += weight * *fg_ptr;
-
-                fg[0] = color_type::downshift(fg[0], image_filter_shift);
-                fg[1] = color_type::downshift(fg[1], image_filter_shift);
-                fg[2] = color_type::downshift(fg[2], image_filter_shift);
-                fg[3] = color_type::downshift(fg[3], image_filter_shift);
-
-                if(fg[order_type::A] > color_type::full_value()) fg[order_type::A] = color_type::full_value();
-                if(fg[order_type::R] > fg[order_type::A]) fg[order_type::R] = fg[order_type::A];
-                if(fg[order_type::G] > fg[order_type::A]) fg[order_type::G] = fg[order_type::A];
-                if(fg[order_type::B] > fg[order_type::A]) fg[order_type::B] = fg[order_type::A];
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = (value_type)fg[order_type::A];
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //==================================================span_image_filter_rgba
-    template<class Source, class Interpolator> 
-    class span_image_filter_rgba : 
-    public span_image_filter<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_filter<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-        typedef typename color_type::long_type long_type;
-
-        //--------------------------------------------------------------------
-        span_image_filter_rgba() {}
-        span_image_filter_rgba(source_type& src, 
-                               interpolator_type& inter,
-                               image_filter_lut& filter) :
-            base_type(src, inter, &filter) 
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[4];
-            const value_type *fg_ptr;
-
-            unsigned     diameter     = base_type::filter().diameter();
-            int          start        = base_type::filter().start();
-            const int16* weight_array = base_type::filter().weight_array();
-
-            int x_count; 
-            int weight_y;
-
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-
-                x -= base_type::filter_dx_int();
-                y -= base_type::filter_dy_int();
-
-                int x_hr = x; 
-                int y_hr = y; 
-
-                int x_lr = x_hr >> image_subpixel_shift;
-                int y_lr = y_hr >> image_subpixel_shift;
-
-                fg[0] = fg[1] = fg[2] = fg[3] = 0;
-
-                int x_fract = x_hr & image_subpixel_mask;
-                unsigned y_count = diameter;
-
-                y_hr = image_subpixel_mask - (y_hr & image_subpixel_mask);
-                fg_ptr = (const value_type*)base_type::source().span(x_lr + start, 
-                                                                     y_lr + start, 
-                                                                     diameter);
-                for(;;)
-                {
-                    x_count  = diameter;
-                    weight_y = weight_array[y_hr];
-                    x_hr = image_subpixel_mask - x_fract;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     image_filter_shift;
-
-                        fg[0] += weight * *fg_ptr++;
-                        fg[1] += weight * *fg_ptr++;
-                        fg[2] += weight * *fg_ptr++;
-                        fg[3] += weight * *fg_ptr;
-
-                        if(--x_count == 0) break;
-                        x_hr  += image_subpixel_scale;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-
-                    if(--y_count == 0) break;
-                    y_hr  += image_subpixel_scale;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg[0] = color_type::downshift(fg[0], image_filter_shift);
-                fg[1] = color_type::downshift(fg[1], image_filter_shift);
-                fg[2] = color_type::downshift(fg[2], image_filter_shift);
-                fg[3] = color_type::downshift(fg[3], image_filter_shift);
-
-                if(fg[0] < 0) fg[0] = 0;
-                if(fg[1] < 0) fg[1] = 0;
-                if(fg[2] < 0) fg[2] = 0;
-                if(fg[3] < 0) fg[3] = 0;
-
-                if(fg[order_type::A] > color_type::full_value()) fg[order_type::A] = color_type::full_value();
-                if(fg[order_type::R] > fg[order_type::A]) fg[order_type::R] = fg[order_type::A];
-                if(fg[order_type::G] > fg[order_type::A]) fg[order_type::G] = fg[order_type::A];
-                if(fg[order_type::B] > fg[order_type::A]) fg[order_type::B] = fg[order_type::A];
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = (value_type)fg[order_type::A];
-                ++span;
-                ++base_type::interpolator();
-
-            } while(--len);
-        }
-    };
-
-
-
-    //========================================span_image_resample_rgba_affine
-    template<class Source> 
-    class span_image_resample_rgba_affine : 
-    public span_image_resample_affine<Source>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef span_image_resample_affine<source_type> base_type;
-        typedef typename base_type::interpolator_type interpolator_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        {
-            downscale_shift = image_filter_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_image_resample_rgba_affine() {}
-        span_image_resample_rgba_affine(source_type& src, 
-                                        interpolator_type& inter,
-                                        image_filter_lut& filter) :
-            base_type(src, inter, filter) 
-        {}
-
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-
-            long_type fg[4];
-
-            int diameter     = base_type::filter().diameter();
-            int filter_scale = diameter << image_subpixel_shift;
-            int radius_x     = (diameter * base_type::m_rx) >> 1;
-            int radius_y     = (diameter * base_type::m_ry) >> 1;
-            int len_x_lr     = 
-                (diameter * base_type::m_rx + image_subpixel_mask) >> 
-                    image_subpixel_shift;
-
-            const int16* weight_array = base_type::filter().weight_array();
-
-            do
-            {
-                base_type::interpolator().coordinates(&x, &y);
-
-                x += base_type::filter_dx_int() - radius_x;
-                y += base_type::filter_dy_int() - radius_y;
-
-                fg[0] = fg[1] = fg[2] = fg[3] = 0;
-
-                int y_lr = y >> image_subpixel_shift;
-                int y_hr = ((image_subpixel_mask - (y & image_subpixel_mask)) * 
-                                base_type::m_ry_inv) >> 
-                                    image_subpixel_shift;
-                int total_weight = 0;
-                int x_lr = x >> image_subpixel_shift;
-                int x_hr = ((image_subpixel_mask - (x & image_subpixel_mask)) * 
-                                base_type::m_rx_inv) >> 
-                                    image_subpixel_shift;
-
-                int x_hr2 = x_hr;
-                const value_type* fg_ptr = 
-                    (const value_type*)base_type::source().span(x_lr, y_lr, len_x_lr);
-                for(;;)
-                {
-                    int weight_y = weight_array[y_hr];
-                    x_hr = x_hr2;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     downscale_shift;
-
-                        fg[0] += *fg_ptr++ * weight;
-                        fg[1] += *fg_ptr++ * weight;
-                        fg[2] += *fg_ptr++ * weight;
-                        fg[3] += *fg_ptr++ * weight;
-                        total_weight += weight;
-                        x_hr  += base_type::m_rx_inv;
-                        if(x_hr >= filter_scale) break;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-                    y_hr += base_type::m_ry_inv;
-                    if(y_hr >= filter_scale) break;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg[0] /= total_weight;
-                fg[1] /= total_weight;
-                fg[2] /= total_weight;
-                fg[3] /= total_weight;
-
-                if(fg[0] < 0) fg[0] = 0;
-                if(fg[1] < 0) fg[1] = 0;
-                if(fg[2] < 0) fg[2] = 0;
-                if(fg[3] < 0) fg[3] = 0;
-
-                if(fg[order_type::A] > color_type::full_value()) fg[order_type::A] = color_type::full_value();
-                if(fg[order_type::R] > fg[order_type::A]) fg[order_type::R] = fg[order_type::A];
-                if(fg[order_type::G] > fg[order_type::A]) fg[order_type::G] = fg[order_type::A];
-                if(fg[order_type::B] > fg[order_type::A]) fg[order_type::B] = fg[order_type::A];
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = (value_type)fg[order_type::A];
-
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-
-    //==============================================span_image_resample_rgba
-    template<class Source, class Interpolator>
-    class span_image_resample_rgba : 
-    public span_image_resample<Source, Interpolator>
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef Interpolator interpolator_type;
-        typedef span_image_resample<source_type, interpolator_type> base_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::long_type long_type;
-        enum base_scale_e
-        {
-            downscale_shift = image_filter_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_image_resample_rgba() {}
-        span_image_resample_rgba(source_type& src, 
-                                 interpolator_type& inter,
-                                 image_filter_lut& filter) :
-            base_type(src, inter, filter)
-        {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {
-            base_type::interpolator().begin(x + base_type::filter_dx_dbl(), 
-                                            y + base_type::filter_dy_dbl(), len);
-            long_type fg[4];
-
-            int diameter = base_type::filter().diameter();
-            int filter_scale = diameter << image_subpixel_shift;
-
-            const int16* weight_array = base_type::filter().weight_array();
-            do
-            {
-                int rx;
-                int ry;
-                int rx_inv = image_subpixel_scale;
-                int ry_inv = image_subpixel_scale;
-                base_type::interpolator().coordinates(&x,  &y);
-                base_type::interpolator().local_scale(&rx, &ry);
-                base_type::adjust_scale(&rx, &ry);
-
-                rx_inv = image_subpixel_scale * image_subpixel_scale / rx;
-                ry_inv = image_subpixel_scale * image_subpixel_scale / ry;
-
-                int radius_x = (diameter * rx) >> 1;
-                int radius_y = (diameter * ry) >> 1;
-                int len_x_lr = 
-                    (diameter * rx + image_subpixel_mask) >> 
-                        image_subpixel_shift;
-
-                x += base_type::filter_dx_int() - radius_x;
-                y += base_type::filter_dy_int() - radius_y;
-
-                fg[0] = fg[1] = fg[2] = fg[3] = 0;
-
-                int y_lr = y >> image_subpixel_shift;
-                int y_hr = ((image_subpixel_mask - (y & image_subpixel_mask)) * 
-                               ry_inv) >> 
-                                   image_subpixel_shift;
-                int total_weight = 0;
-                int x_lr = x >> image_subpixel_shift;
-                int x_hr = ((image_subpixel_mask - (x & image_subpixel_mask)) * 
-                               rx_inv) >> 
-                                   image_subpixel_shift;
-                int x_hr2 = x_hr;
-                const value_type* fg_ptr = 
-                    (const value_type*)base_type::source().span(x_lr, y_lr, len_x_lr);
-
-                for(;;)
-                {
-                    int weight_y = weight_array[y_hr];
-                    x_hr = x_hr2;
-                    for(;;)
-                    {
-                        int weight = (weight_y * weight_array[x_hr] + 
-                                     image_filter_scale / 2) >> 
-                                     downscale_shift;
-                        fg[0] += *fg_ptr++ * weight;
-                        fg[1] += *fg_ptr++ * weight;
-                        fg[2] += *fg_ptr++ * weight;
-                        fg[3] += *fg_ptr++ * weight;
-                        total_weight += weight;
-                        x_hr  += rx_inv;
-                        if(x_hr >= filter_scale) break;
-                        fg_ptr = (const value_type*)base_type::source().next_x();
-                    }
-                    y_hr += ry_inv;
-                    if(y_hr >= filter_scale) break;
-                    fg_ptr = (const value_type*)base_type::source().next_y();
-                }
-
-                fg[0] /= total_weight;
-                fg[1] /= total_weight;
-                fg[2] /= total_weight;
-                fg[3] /= total_weight;
-
-                if(fg[0] < 0) fg[0] = 0;
-                if(fg[1] < 0) fg[1] = 0;
-                if(fg[2] < 0) fg[2] = 0;
-                if(fg[3] < 0) fg[3] = 0;
-
-                if(fg[order_type::A] > color_type::full_value()) fg[order_type::A] = color_type::full_value();
-                if(fg[order_type::R] > fg[order_type::R]) fg[order_type::R] = fg[order_type::R];
-                if(fg[order_type::G] > fg[order_type::G]) fg[order_type::G] = fg[order_type::G];
-                if(fg[order_type::B] > fg[order_type::B]) fg[order_type::B] = fg[order_type::B];
-
-                span->r = (value_type)fg[order_type::R];
-                span->g = (value_type)fg[order_type::G];
-                span->b = (value_type)fg[order_type::B];
-                span->a = (value_type)fg[order_type::A];
-
-                ++span;
-                ++base_type::interpolator();
-            } while(--len);
-        }
-    };
-
-
-}
-
-
-#endif
-
-
-
diff --git a/xs/src/agg/agg_span_interpolator_adaptor.h b/xs/src/agg/agg_span_interpolator_adaptor.h
deleted file mode 100644
index 0fdfa7747..000000000
--- a/xs/src/agg/agg_span_interpolator_adaptor.h
+++ /dev/null
@@ -1,77 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_INTERPOLATOR_ADAPTOR_INCLUDED
-#define AGG_SPAN_INTERPOLATOR_ADAPTOR_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //===============================================span_interpolator_adaptor
-    template<class Interpolator, class Distortion>
-    class span_interpolator_adaptor : public Interpolator
-    {
-    public:
-        typedef Interpolator base_type;
-        typedef typename base_type::trans_type trans_type;
-        typedef Distortion distortion_type;
-
-        //--------------------------------------------------------------------
-        span_interpolator_adaptor() {}
-        span_interpolator_adaptor(trans_type& trans, 
-                                  distortion_type& dist) :
-            base_type(trans),
-            m_distortion(&dist)
-        {   
-        }
-
-        //--------------------------------------------------------------------
-        span_interpolator_adaptor(trans_type& trans,
-                                  distortion_type& dist,
-                                  double x, double y, unsigned len) :
-            base_type(trans, x, y, len),
-            m_distortion(&dist)
-        {
-        }
-
-        //--------------------------------------------------------------------
-        distortion_type& distortion() const
-        {
-            return *m_distortion;
-        }
-
-        //--------------------------------------------------------------------
-        void distortion(distortion_type& dist)
-        {
-            m_distortion = dist;
-        }
-
-        //--------------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            base_type::coordinates(x, y);
-            m_distortion->calculate(x, y);
-        }
-
-    private:
-        //--------------------------------------------------------------------
-        distortion_type* m_distortion;
-    };
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_span_interpolator_linear.h b/xs/src/agg/agg_span_interpolator_linear.h
deleted file mode 100644
index ef10505ce..000000000
--- a/xs/src/agg/agg_span_interpolator_linear.h
+++ /dev/null
@@ -1,232 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_INTERPOLATOR_LINEAR_INCLUDED
-#define AGG_SPAN_INTERPOLATOR_LINEAR_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_dda_line.h"
-#include "agg_trans_affine.h"
-
-namespace agg
-{
-
-    //================================================span_interpolator_linear
-    template<class Transformer = trans_affine, unsigned SubpixelShift = 8> 
-    class span_interpolator_linear
-    {
-    public:
-        typedef Transformer trans_type;
-
-        enum subpixel_scale_e
-        {
-            subpixel_shift = SubpixelShift,
-            subpixel_scale  = 1 << subpixel_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_interpolator_linear() {}
-        span_interpolator_linear(trans_type& trans) : m_trans(&trans) {}
-        span_interpolator_linear(trans_type& trans,
-                                 double x, double y, unsigned len) :
-            m_trans(&trans)
-        {
-            begin(x, y, len);
-        }
-
-        //----------------------------------------------------------------
-        const trans_type& transformer() const { return *m_trans; }
-        void transformer(trans_type& trans) { m_trans = &trans; }
-
-        //----------------------------------------------------------------
-        void begin(double x, double y, unsigned len)
-        {
-            double tx;
-            double ty;
-
-            tx = x;
-            ty = y;
-            m_trans->transform(&tx, &ty);
-            int x1 = iround(tx * subpixel_scale);
-            int y1 = iround(ty * subpixel_scale);
-
-            tx = x + len;
-            ty = y;
-            m_trans->transform(&tx, &ty);
-            int x2 = iround(tx * subpixel_scale);
-            int y2 = iround(ty * subpixel_scale);
-
-            m_li_x = dda2_line_interpolator(x1, x2, len);
-            m_li_y = dda2_line_interpolator(y1, y2, len);
-        }
-
-        //----------------------------------------------------------------
-        void resynchronize(double xe, double ye, unsigned len)
-        {
-            m_trans->transform(&xe, &ye);
-            m_li_x = dda2_line_interpolator(m_li_x.y(), iround(xe * subpixel_scale), len);
-            m_li_y = dda2_line_interpolator(m_li_y.y(), iround(ye * subpixel_scale), len);
-        }
-    
-        //----------------------------------------------------------------
-        void operator++()
-        {
-            ++m_li_x;
-            ++m_li_y;
-        }
-
-        //----------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            *x = m_li_x.y();
-            *y = m_li_y.y();
-        }
-
-    private:
-        trans_type* m_trans;
-        dda2_line_interpolator m_li_x;
-        dda2_line_interpolator m_li_y;
-    };
-
-
-
-
-
-
-    //=====================================span_interpolator_linear_subdiv
-    template<class Transformer = trans_affine, unsigned SubpixelShift = 8> 
-    class span_interpolator_linear_subdiv
-    {
-    public:
-        typedef Transformer trans_type;
-
-        enum subpixel_scale_e
-        {
-            subpixel_shift = SubpixelShift,
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-
-        //----------------------------------------------------------------
-        span_interpolator_linear_subdiv() :
-            m_subdiv_shift(4),
-            m_subdiv_size(1 << m_subdiv_shift),
-            m_subdiv_mask(m_subdiv_size - 1) {}
-
-        span_interpolator_linear_subdiv(trans_type& trans, 
-                                        unsigned subdiv_shift = 4) : 
-            m_subdiv_shift(subdiv_shift),
-            m_subdiv_size(1 << m_subdiv_shift),
-            m_subdiv_mask(m_subdiv_size - 1),
-            m_trans(&trans) {}
-
-        span_interpolator_linear_subdiv(trans_type& trans,
-                                        double x, double y, unsigned len,
-                                        unsigned subdiv_shift = 4) :
-            m_subdiv_shift(subdiv_shift),
-            m_subdiv_size(1 << m_subdiv_shift),
-            m_subdiv_mask(m_subdiv_size - 1),
-            m_trans(&trans)
-        {
-            begin(x, y, len);
-        }
-
-        //----------------------------------------------------------------
-        const trans_type& transformer() const { return *m_trans; }
-        void transformer(const trans_type& trans) { m_trans = &trans; }
-
-        //----------------------------------------------------------------
-        unsigned subdiv_shift() const { return m_subdiv_shift; }
-        void subdiv_shift(unsigned shift) 
-        {
-            m_subdiv_shift = shift;
-            m_subdiv_size = 1 << m_subdiv_shift;
-            m_subdiv_mask = m_subdiv_size - 1;
-        }
-
-        //----------------------------------------------------------------
-        void begin(double x, double y, unsigned len)
-        {
-            double tx;
-            double ty;
-            m_pos   = 1;
-            m_src_x = iround(x * subpixel_scale) + subpixel_scale;
-            m_src_y = y;
-            m_len   = len;
-
-            if(len > m_subdiv_size) len = m_subdiv_size;
-            tx = x;
-            ty = y;
-            m_trans->transform(&tx, &ty);
-            int x1 = iround(tx * subpixel_scale);
-            int y1 = iround(ty * subpixel_scale);
-
-            tx = x + len;
-            ty = y;
-            m_trans->transform(&tx, &ty);
-
-            m_li_x = dda2_line_interpolator(x1, iround(tx * subpixel_scale), len);
-            m_li_y = dda2_line_interpolator(y1, iround(ty * subpixel_scale), len);
-        }
-
-        //----------------------------------------------------------------
-        void operator++()
-        {
-            ++m_li_x;
-            ++m_li_y;
-            if(m_pos >= m_subdiv_size)
-            {
-                unsigned len = m_len;
-                if(len > m_subdiv_size) len = m_subdiv_size;
-                double tx = double(m_src_x) / double(subpixel_scale) + len;
-                double ty = m_src_y;
-                m_trans->transform(&tx, &ty);
-                m_li_x = dda2_line_interpolator(m_li_x.y(), iround(tx * subpixel_scale), len);
-                m_li_y = dda2_line_interpolator(m_li_y.y(), iround(ty * subpixel_scale), len);
-                m_pos = 0;
-            }
-            m_src_x += subpixel_scale;
-            ++m_pos;
-            --m_len;
-        }
-
-        //----------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            *x = m_li_x.y();
-            *y = m_li_y.y();
-        }
-
-    private:
-        unsigned m_subdiv_shift;
-        unsigned m_subdiv_size;
-        unsigned m_subdiv_mask;
-        trans_type* m_trans;
-        dda2_line_interpolator m_li_x;
-        dda2_line_interpolator m_li_y;
-        int      m_src_x;
-        double   m_src_y;
-        unsigned m_pos;
-        unsigned m_len;
-    };
-
-
-}
-
-
-
-#endif
-
-
diff --git a/xs/src/agg/agg_span_interpolator_persp.h b/xs/src/agg/agg_span_interpolator_persp.h
deleted file mode 100644
index cad437e04..000000000
--- a/xs/src/agg/agg_span_interpolator_persp.h
+++ /dev/null
@@ -1,462 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_SPAN_INTERPOLATOR_PERSP_INCLUDED
-#define AGG_SPAN_INTERPOLATOR_PERSP_INCLUDED
-
-#include "agg_trans_perspective.h"
-#include "agg_dda_line.h"
-
-namespace agg
-{
-
-
-
-    //===========================================span_interpolator_persp_exact
-    template<unsigned SubpixelShift = 8> 
-    class span_interpolator_persp_exact
-    {
-    public:
-        typedef trans_perspective trans_type;
-        typedef trans_perspective::iterator_x iterator_type;
-        enum subpixel_scale_e
-        {
-            subpixel_shift = SubpixelShift,
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_interpolator_persp_exact() {}
-
-        //--------------------------------------------------------------------
-        // Arbitrary quadrangle transformations
-        span_interpolator_persp_exact(const double* src, const double* dst) 
-        {
-            quad_to_quad(src, dst);
-        }
-
-        //--------------------------------------------------------------------
-        // Direct transformations 
-        span_interpolator_persp_exact(double x1, double y1, 
-                                      double x2, double y2, 
-                                      const double* quad)
-        {
-            rect_to_quad(x1, y1, x2, y2, quad);
-        }
-
-        //--------------------------------------------------------------------
-        // Reverse transformations 
-        span_interpolator_persp_exact(const double* quad, 
-                                      double x1, double y1, 
-                                      double x2, double y2)
-        {
-            quad_to_rect(quad, x1, y1, x2, y2);
-        }
-
-        //--------------------------------------------------------------------
-        // Set the transformations using two arbitrary quadrangles.
-        void quad_to_quad(const double* src, const double* dst)
-        {
-            m_trans_dir.quad_to_quad(src, dst);
-            m_trans_inv.quad_to_quad(dst, src);
-        }
-
-        //--------------------------------------------------------------------
-        // Set the direct transformations, i.e., rectangle -> quadrangle
-        void rect_to_quad(double x1, double y1, double x2, double y2, 
-                          const double* quad)
-        {
-            double src[8];
-            src[0] = src[6] = x1;
-            src[2] = src[4] = x2;
-            src[1] = src[3] = y1;
-            src[5] = src[7] = y2;
-            quad_to_quad(src, quad);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Set the reverse transformations, i.e., quadrangle -> rectangle
-        void quad_to_rect(const double* quad, 
-                          double x1, double y1, double x2, double y2)
-        {
-            double dst[8];
-            dst[0] = dst[6] = x1;
-            dst[2] = dst[4] = x2;
-            dst[1] = dst[3] = y1;
-            dst[5] = dst[7] = y2;
-            quad_to_quad(quad, dst);
-        }
-
-        //--------------------------------------------------------------------
-        // Check if the equations were solved successfully
-        bool is_valid() const { return m_trans_dir.is_valid(); }
-
-        //----------------------------------------------------------------
-        void begin(double x, double y, unsigned len)
-        {
-            m_iterator = m_trans_dir.begin(x, y, 1.0);
-            double xt = m_iterator.x;
-            double yt = m_iterator.y;
-
-            double dx;
-            double dy;
-            const double delta = 1/double(subpixel_scale);
-            dx = xt + delta;
-            dy = yt;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sx1 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-            dx = xt;
-            dy = yt + delta;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sy1 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            x += len;
-            xt = x;
-            yt = y;
-            m_trans_dir.transform(&xt, &yt);
-
-            dx = xt + delta;
-            dy = yt;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sx2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-            dx = xt;
-            dy = yt + delta;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sy2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            m_scale_x = dda2_line_interpolator(sx1, sx2, len);
-            m_scale_y = dda2_line_interpolator(sy1, sy2, len);
-        }
-
-
-        //----------------------------------------------------------------
-        void resynchronize(double xe, double ye, unsigned len)
-        {
-            // Assume x1,y1 are equal to the ones at the previous end point 
-            int sx1 = m_scale_x.y();
-            int sy1 = m_scale_y.y();
-
-            // Calculate transformed coordinates at x2,y2 
-            double xt = xe;
-            double yt = ye;
-            m_trans_dir.transform(&xt, &yt);
-
-            const double delta = 1/double(subpixel_scale);
-            double dx;
-            double dy;
-
-            // Calculate scale by X at x2,y2
-            dx = xt + delta;
-            dy = yt;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= xe;
-            dy -= ye;
-            int sx2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Calculate scale by Y at x2,y2
-            dx = xt;
-            dy = yt + delta;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= xe;
-            dy -= ye;
-            int sy2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Initialize the interpolators
-            m_scale_x = dda2_line_interpolator(sx1, sx2, len);
-            m_scale_y = dda2_line_interpolator(sy1, sy2, len);
-        }
-
-
-
-        //----------------------------------------------------------------
-        void operator++()
-        {
-            ++m_iterator;
-            ++m_scale_x;
-            ++m_scale_y;
-        }
-
-        //----------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            *x = iround(m_iterator.x * subpixel_scale);
-            *y = iround(m_iterator.y * subpixel_scale);
-        }
-
-        //----------------------------------------------------------------
-        void local_scale(int* x, int* y)
-        {
-            *x = m_scale_x.y();
-            *y = m_scale_y.y();
-        }
-
-        //----------------------------------------------------------------
-        void transform(double* x, double* y) const
-        {
-            m_trans_dir.transform(x, y);
-        }
-        
-    private:
-        trans_type             m_trans_dir;
-        trans_type             m_trans_inv;
-        iterator_type          m_iterator;
-        dda2_line_interpolator m_scale_x;
-        dda2_line_interpolator m_scale_y;
-    };
-
-
-
-
-
-
-
-
-
-
-
-    //============================================span_interpolator_persp_lerp
-    template<unsigned SubpixelShift = 8> 
-    class span_interpolator_persp_lerp
-    {
-    public:
-        typedef trans_perspective trans_type;
-        enum subpixel_scale_e
-        {
-            subpixel_shift = SubpixelShift,
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_interpolator_persp_lerp() {}
-
-        //--------------------------------------------------------------------
-        // Arbitrary quadrangle transformations
-        span_interpolator_persp_lerp(const double* src, const double* dst) 
-        {
-            quad_to_quad(src, dst);
-        }
-
-        //--------------------------------------------------------------------
-        // Direct transformations 
-        span_interpolator_persp_lerp(double x1, double y1, 
-                                     double x2, double y2, 
-                                     const double* quad)
-        {
-            rect_to_quad(x1, y1, x2, y2, quad);
-        }
-
-        //--------------------------------------------------------------------
-        // Reverse transformations 
-        span_interpolator_persp_lerp(const double* quad, 
-                                     double x1, double y1, 
-                                     double x2, double y2)
-        {
-            quad_to_rect(quad, x1, y1, x2, y2);
-        }
-
-        //--------------------------------------------------------------------
-        // Set the transformations using two arbitrary quadrangles.
-        void quad_to_quad(const double* src, const double* dst)
-        {
-            m_trans_dir.quad_to_quad(src, dst);
-            m_trans_inv.quad_to_quad(dst, src);
-        }
-
-        //--------------------------------------------------------------------
-        // Set the direct transformations, i.e., rectangle -> quadrangle
-        void rect_to_quad(double x1, double y1, double x2, double y2, 
-                          const double* quad)
-        {
-            double src[8];
-            src[0] = src[6] = x1;
-            src[2] = src[4] = x2;
-            src[1] = src[3] = y1;
-            src[5] = src[7] = y2;
-            quad_to_quad(src, quad);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Set the reverse transformations, i.e., quadrangle -> rectangle
-        void quad_to_rect(const double* quad, 
-                          double x1, double y1, double x2, double y2)
-        {
-            double dst[8];
-            dst[0] = dst[6] = x1;
-            dst[2] = dst[4] = x2;
-            dst[1] = dst[3] = y1;
-            dst[5] = dst[7] = y2;
-            quad_to_quad(quad, dst);
-        }
-
-        //--------------------------------------------------------------------
-        // Check if the equations were solved successfully
-        bool is_valid() const { return m_trans_dir.is_valid(); }
-
-        //----------------------------------------------------------------
-        void begin(double x, double y, unsigned len)
-        {
-            // Calculate transformed coordinates at x1,y1 
-            double xt = x;
-            double yt = y;
-            m_trans_dir.transform(&xt, &yt);
-            int x1 = iround(xt * subpixel_scale);
-            int y1 = iround(yt * subpixel_scale);
-
-            double dx;
-            double dy;
-            const double delta = 1/double(subpixel_scale);
-
-            // Calculate scale by X at x1,y1
-            dx = xt + delta;
-            dy = yt;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sx1 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Calculate scale by Y at x1,y1
-            dx = xt;
-            dy = yt + delta;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sy1 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Calculate transformed coordinates at x2,y2 
-            x += len;
-            xt = x;
-            yt = y;
-            m_trans_dir.transform(&xt, &yt);
-            int x2 = iround(xt * subpixel_scale);
-            int y2 = iround(yt * subpixel_scale);
-
-            // Calculate scale by X at x2,y2
-            dx = xt + delta;
-            dy = yt;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sx2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Calculate scale by Y at x2,y2
-            dx = xt;
-            dy = yt + delta;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= x;
-            dy -= y;
-            int sy2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Initialize the interpolators
-            m_coord_x = dda2_line_interpolator(x1,  x2,  len);
-            m_coord_y = dda2_line_interpolator(y1,  y2,  len);
-            m_scale_x = dda2_line_interpolator(sx1, sx2, len);
-            m_scale_y = dda2_line_interpolator(sy1, sy2, len);
-        }
-
-
-        //----------------------------------------------------------------
-        void resynchronize(double xe, double ye, unsigned len)
-        {
-            // Assume x1,y1 are equal to the ones at the previous end point 
-            int x1  = m_coord_x.y();
-            int y1  = m_coord_y.y();
-            int sx1 = m_scale_x.y();
-            int sy1 = m_scale_y.y();
-
-            // Calculate transformed coordinates at x2,y2 
-            double xt = xe;
-            double yt = ye;
-            m_trans_dir.transform(&xt, &yt);
-            int x2 = iround(xt * subpixel_scale);
-            int y2 = iround(yt * subpixel_scale);
-
-            const double delta = 1/double(subpixel_scale);
-            double dx;
-            double dy;
-
-            // Calculate scale by X at x2,y2
-            dx = xt + delta;
-            dy = yt;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= xe;
-            dy -= ye;
-            int sx2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Calculate scale by Y at x2,y2
-            dx = xt;
-            dy = yt + delta;
-            m_trans_inv.transform(&dx, &dy);
-            dx -= xe;
-            dy -= ye;
-            int sy2 = uround(subpixel_scale/sqrt(dx*dx + dy*dy)) >> subpixel_shift;
-
-            // Initialize the interpolators
-            m_coord_x = dda2_line_interpolator(x1,  x2,  len);
-            m_coord_y = dda2_line_interpolator(y1,  y2,  len);
-            m_scale_x = dda2_line_interpolator(sx1, sx2, len);
-            m_scale_y = dda2_line_interpolator(sy1, sy2, len);
-        }
-
-
-        //----------------------------------------------------------------
-        void operator++()
-        {
-            ++m_coord_x;
-            ++m_coord_y;
-            ++m_scale_x;
-            ++m_scale_y;
-        }
-
-        //----------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            *x = m_coord_x.y();
-            *y = m_coord_y.y();
-        }
-
-        //----------------------------------------------------------------
-        void local_scale(int* x, int* y)
-        {
-            *x = m_scale_x.y();
-            *y = m_scale_y.y();
-        }
-
-        //----------------------------------------------------------------
-        void transform(double* x, double* y) const
-        {
-            m_trans_dir.transform(x, y);
-        }
-        
-    private:
-        trans_type             m_trans_dir;
-        trans_type             m_trans_inv;
-        dda2_line_interpolator m_coord_x;
-        dda2_line_interpolator m_coord_y;
-        dda2_line_interpolator m_scale_x;
-        dda2_line_interpolator m_scale_y;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_interpolator_trans.h b/xs/src/agg/agg_span_interpolator_trans.h
deleted file mode 100644
index 32bc678a8..000000000
--- a/xs/src/agg/agg_span_interpolator_trans.h
+++ /dev/null
@@ -1,92 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Horizontal span interpolator for use with an arbitrary transformer
-// The efficiency highly depends on the operations done in the transformer
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_INTERPOLATOR_TRANS_INCLUDED
-#define AGG_SPAN_INTERPOLATOR_TRANS_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //=================================================span_interpolator_trans
-    template<class Transformer, unsigned SubpixelShift = 8> 
-    class span_interpolator_trans
-    {
-    public:
-        typedef Transformer trans_type;
-        enum subpixel_scale_e
-        {
-            subpixel_shift = SubpixelShift,
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-        //--------------------------------------------------------------------
-        span_interpolator_trans() {}
-        span_interpolator_trans(trans_type& trans) : m_trans(&trans) {}
-        span_interpolator_trans(trans_type& trans,
-                                double x, double y, unsigned) :
-            m_trans(&trans)
-        {
-            begin(x, y, 0);
-        }
-
-        //----------------------------------------------------------------
-        const trans_type& transformer() const { return *m_trans; }
-        void transformer(const trans_type& trans) { m_trans = &trans; }
-
-        //----------------------------------------------------------------
-        void begin(double x, double y, unsigned)
-        {
-            m_x = x;
-            m_y = y;
-            m_trans->transform(&x, &y);
-            m_ix = iround(x * subpixel_scale);
-            m_iy = iround(y * subpixel_scale);
-        }
-
-        //----------------------------------------------------------------
-        void operator++()
-        {
-            m_x += 1.0;
-            double x = m_x;
-            double y = m_y;
-            m_trans->transform(&x, &y);
-            m_ix = iround(x * subpixel_scale);
-            m_iy = iround(y * subpixel_scale);
-        }
-
-        //----------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            *x = m_ix;
-            *y = m_iy;
-        }
-
-    private:
-        trans_type*       m_trans;
-        double            m_x;
-        double            m_y;
-        int               m_ix;
-        int               m_iy;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_pattern_gray.h b/xs/src/agg/agg_span_pattern_gray.h
deleted file mode 100644
index ae1a49f87..000000000
--- a/xs/src/agg/agg_span_pattern_gray.h
+++ /dev/null
@@ -1,93 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-
-#ifndef AGG_SPAN_PATTERN_GRAY_INCLUDED
-#define AGG_SPAN_PATTERN_GRAY_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //=======================================================span_pattern_gray
-    template<class Source> class span_pattern_gray
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-
-        //--------------------------------------------------------------------
-        span_pattern_gray() {}
-        span_pattern_gray(source_type& src, 
-                          unsigned offset_x, unsigned offset_y) :
-            m_src(&src),
-            m_offset_x(offset_x),
-            m_offset_y(offset_y),
-            m_alpha(color_type::base_mask)
-        {}
-
-        //--------------------------------------------------------------------
-        void   attach(source_type& v)      { m_src = &v; }
-               source_type& source()       { return *m_src; }
-        const  source_type& source() const { return *m_src; }
-
-        //--------------------------------------------------------------------
-        void       offset_x(unsigned v) { m_offset_x = v; }
-        void       offset_y(unsigned v) { m_offset_y = v; }
-        unsigned   offset_x() const { return m_offset_x; }
-        unsigned   offset_y() const { return m_offset_y; }
-        void       alpha(value_type v) { m_alpha = v; }
-        value_type alpha() const { return m_alpha; }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-        void generate(color_type* span, int x, int y, unsigned len)
-        {   
-            x += m_offset_x;
-            y += m_offset_y;
-            const value_type* p = (const value_type*)m_src->span(x, y, len);
-            do
-            {
-                span->v = *p;
-                span->a = m_alpha;
-                p = m_src->next_x();
-                ++span;
-            }
-            while(--len);
-        }
-
-    private:
-        source_type* m_src;
-        unsigned     m_offset_x;
-        unsigned     m_offset_y;
-        value_type   m_alpha;
-
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_span_pattern_rgb.h b/xs/src/agg/agg_span_pattern_rgb.h
deleted file mode 100644
index 4850508af..000000000
--- a/xs/src/agg/agg_span_pattern_rgb.h
+++ /dev/null
@@ -1,96 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-
-#ifndef AGG_SPAN_PATTERN_RGB_INCLUDED
-#define AGG_SPAN_PATTERN_RGB_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //========================================================span_pattern_rgb
-    template<class Source> class span_pattern_rgb
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-
-        //--------------------------------------------------------------------
-        span_pattern_rgb() {}
-        span_pattern_rgb(source_type& src, 
-                         unsigned offset_x, unsigned offset_y) :
-            m_src(&src),
-            m_offset_x(offset_x),
-            m_offset_y(offset_y),
-            m_alpha(color_type::base_mask)
-        {}
-
-        //--------------------------------------------------------------------
-        void   attach(source_type& v)      { m_src = &v; }
-               source_type& source()       { return *m_src; }
-        const  source_type& source() const { return *m_src; }
-
-        //--------------------------------------------------------------------
-        void       offset_x(unsigned v) { m_offset_x = v; }
-        void       offset_y(unsigned v) { m_offset_y = v; }
-        unsigned   offset_x() const { return m_offset_x; }
-        unsigned   offset_y() const { return m_offset_y; }
-        void       alpha(value_type v) { m_alpha = v; }
-        value_type alpha() const { return m_alpha; }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-        void generate(color_type* span, int x, int y, unsigned len)
-        {   
-            x += m_offset_x;
-            y += m_offset_y;
-            const value_type* p = (const value_type*)m_src->span(x, y, len);
-            do
-            {
-                span->r = p[order_type::R];
-                span->g = p[order_type::G];
-                span->b = p[order_type::B];
-                span->a = m_alpha;
-                p = m_src->next_x();
-                ++span;
-            }
-            while(--len);
-        }
-
-    private:
-        source_type* m_src;
-        unsigned     m_offset_x;
-        unsigned     m_offset_y;
-        value_type   m_alpha;
-
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_span_pattern_rgba.h b/xs/src/agg/agg_span_pattern_rgba.h
deleted file mode 100644
index d47d2a6c0..000000000
--- a/xs/src/agg/agg_span_pattern_rgba.h
+++ /dev/null
@@ -1,94 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Adaptation for high precision colors has been sponsored by 
-// Liberty Technology Systems, Inc., visit http://lib-sys.com
-//
-// Liberty Technology Systems, Inc. is the provider of
-// PostScript and PDF technology for software developers.
-// 
-//----------------------------------------------------------------------------
-
-
-#ifndef AGG_SPAN_PATTERN_RGBA_INCLUDED
-#define AGG_SPAN_PATTERN_RGBA_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //======================================================span_pattern_rgba
-    template<class Source> class span_pattern_rgba
-    {
-    public:
-        typedef Source source_type;
-        typedef typename source_type::color_type color_type;
-        typedef typename source_type::order_type order_type;
-        typedef typename color_type::value_type value_type;
-        typedef typename color_type::calc_type calc_type;
-
-        //--------------------------------------------------------------------
-        span_pattern_rgba() {}
-        span_pattern_rgba(source_type& src, 
-                          unsigned offset_x, unsigned offset_y) :
-            m_src(&src),
-            m_offset_x(offset_x),
-            m_offset_y(offset_y)
-        {}
-
-        //--------------------------------------------------------------------
-        void   attach(source_type& v)      { m_src = &v; }
-               source_type& source()       { return *m_src; }
-        const  source_type& source() const { return *m_src; }
-
-        //--------------------------------------------------------------------
-        void       offset_x(unsigned v) { m_offset_x = v; }
-        void       offset_y(unsigned v) { m_offset_y = v; }
-        unsigned   offset_x() const { return m_offset_x; }
-        unsigned   offset_y() const { return m_offset_y; }
-        void       alpha(value_type) {}
-        value_type alpha() const { return 0; }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-        void generate(color_type* span, int x, int y, unsigned len)
-        {   
-            x += m_offset_x;
-            y += m_offset_y;
-            const value_type* p = (const value_type*)m_src->span(x, y, len);
-            do
-            {
-                span->r = p[order_type::R];
-                span->g = p[order_type::G];
-                span->b = p[order_type::B];
-                span->a = p[order_type::A];
-                p = (const value_type*)m_src->next_x();
-                ++span;
-            }
-            while(--len);
-        }
-
-    private:
-        source_type* m_src;
-        unsigned     m_offset_x;
-        unsigned     m_offset_y;
-
-    };
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_span_solid.h b/xs/src/agg/agg_span_solid.h
deleted file mode 100644
index ee46df999..000000000
--- a/xs/src/agg/agg_span_solid.h
+++ /dev/null
@@ -1,53 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// span_solid_rgba8
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_SPAN_SOLID_INCLUDED
-#define AGG_SPAN_SOLID_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-    //--------------------------------------------------------------span_solid
-    template<class ColorT> class span_solid
-    {
-    public:
-        typedef ColorT color_type;
-
-        //--------------------------------------------------------------------
-        void color(const color_type& c) { m_color = c; }
-        const color_type& color() const { return m_color; }
-
-        //--------------------------------------------------------------------
-        void prepare() {}
-
-        //--------------------------------------------------------------------
-        void generate(color_type* span, int x, int y, unsigned len)
-        {   
-            do { *span++ = m_color; } while(--len);
-        }
-
-    private:
-        color_type m_color;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_span_subdiv_adaptor.h b/xs/src/agg/agg_span_subdiv_adaptor.h
deleted file mode 100644
index b5b855ec9..000000000
--- a/xs/src/agg/agg_span_subdiv_adaptor.h
+++ /dev/null
@@ -1,141 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-#ifndef AGG_SPAN_SUBDIV_ADAPTOR_INCLUDED
-#define AGG_SPAN_SUBDIV_ADAPTOR_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //=================================================span_subdiv_adaptor
-    template<class Interpolator, unsigned SubpixelShift = 8> 
-    class span_subdiv_adaptor
-    {
-    public:
-        typedef Interpolator interpolator_type;
-        typedef typename interpolator_type::trans_type trans_type;
-
-        enum sublixel_scale_e
-        {
-            subpixel_shift = SubpixelShift,
-            subpixel_scale = 1 << subpixel_shift
-        };
-
-
-        //----------------------------------------------------------------
-        span_subdiv_adaptor() :
-            m_subdiv_shift(4),
-            m_subdiv_size(1 << m_subdiv_shift),
-            m_subdiv_mask(m_subdiv_size - 1) {}
-
-        span_subdiv_adaptor(interpolator_type& interpolator, 
-                             unsigned subdiv_shift = 4) : 
-            m_subdiv_shift(subdiv_shift),
-            m_subdiv_size(1 << m_subdiv_shift),
-            m_subdiv_mask(m_subdiv_size - 1),
-            m_interpolator(&interpolator) {}
-
-        span_subdiv_adaptor(interpolator_type& interpolator, 
-                             double x, double y, unsigned len,
-                             unsigned subdiv_shift = 4) :
-            m_subdiv_shift(subdiv_shift),
-            m_subdiv_size(1 << m_subdiv_shift),
-            m_subdiv_mask(m_subdiv_size - 1),
-            m_interpolator(&interpolator)
-        {
-            begin(x, y, len);
-        }
-
-
-        //----------------------------------------------------------------
-        const interpolator_type& interpolator() const { return *m_interpolator; }
-        void interpolator(interpolator_type& intr) { m_interpolator = &intr; }
-
-        //----------------------------------------------------------------
-        const trans_type& transformer() const 
-        { 
-            return *m_interpolator->transformer(); 
-        }
-        void transformer(const trans_type& trans) 
-        { 
-            m_interpolator->transformer(trans); 
-        }
-
-        //----------------------------------------------------------------
-        unsigned subdiv_shift() const { return m_subdiv_shift; }
-        void subdiv_shift(unsigned shift) 
-        {
-            m_subdiv_shift = shift;
-            m_subdiv_size = 1 << m_subdiv_shift;
-            m_subdiv_mask = m_subdiv_size - 1;
-        }
-
-        //----------------------------------------------------------------
-        void begin(double x, double y, unsigned len)
-        {
-            m_pos   = 1;
-            m_src_x = iround(x * subpixel_scale) + subpixel_scale;
-            m_src_y = y;
-            m_len   = len;
-            if(len > m_subdiv_size) len = m_subdiv_size;
-            m_interpolator->begin(x, y, len);
-        }
-
-        //----------------------------------------------------------------
-        void operator++()
-        {
-            ++(*m_interpolator);
-            if(m_pos >= m_subdiv_size)
-            {
-                unsigned len = m_len;
-                if(len > m_subdiv_size) len = m_subdiv_size;
-                m_interpolator->resynchronize(double(m_src_x) / double(subpixel_scale) + len, 
-                                              m_src_y, 
-                                              len);
-                m_pos = 0;
-            }
-            m_src_x += subpixel_scale;
-            ++m_pos;
-            --m_len;
-        }
-
-        //----------------------------------------------------------------
-        void coordinates(int* x, int* y) const
-        {
-            m_interpolator->coordinates(x, y);
-        }
-
-        //----------------------------------------------------------------
-        void local_scale(int* x, int* y) const
-        {
-            m_interpolator->local_scale(x, y);
-        }
-
-
-    private:
-        unsigned m_subdiv_shift;
-        unsigned m_subdiv_size;
-        unsigned m_subdiv_mask;
-        interpolator_type* m_interpolator;
-        int      m_src_x;
-        double   m_src_y;
-        unsigned m_pos;
-        unsigned m_len;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_trans_bilinear.h b/xs/src/agg/agg_trans_bilinear.h
deleted file mode 100644
index f3ab59647..000000000
--- a/xs/src/agg/agg_trans_bilinear.h
+++ /dev/null
@@ -1,166 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Bilinear 2D transformations
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_TRANS_BILINEAR_INCLUDED
-#define AGG_TRANS_BILINEAR_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_simul_eq.h"
-
-namespace agg
-{
-
-    //==========================================================trans_bilinear
-    class trans_bilinear
-    {
-    public:
-        //--------------------------------------------------------------------
-        trans_bilinear() : m_valid(false) {}
-
-        //--------------------------------------------------------------------
-        // Arbitrary quadrangle transformations
-        trans_bilinear(const double* src, const double* dst) 
-        {
-            quad_to_quad(src, dst);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Direct transformations 
-        trans_bilinear(double x1, double y1, double x2, double y2, 
-                       const double* quad)
-        {
-            rect_to_quad(x1, y1, x2, y2, quad);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Reverse transformations 
-        trans_bilinear(const double* quad, 
-                       double x1, double y1, double x2, double y2)
-        {
-            quad_to_rect(quad, x1, y1, x2, y2);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Set the transformations using two arbitrary quadrangles.
-        void quad_to_quad(const double* src, const double* dst)
-        {
-            double left[4][4];
-            double right[4][2];
-
-            unsigned i;
-            for(i = 0; i < 4; i++)
-            {
-                unsigned ix = i * 2;
-                unsigned iy = ix + 1;
-                left[i][0] = 1.0;
-                left[i][1] = src[ix] * src[iy];
-                left[i][2] = src[ix];
-                left[i][3] = src[iy];
-
-                right[i][0] = dst[ix];
-                right[i][1] = dst[iy];
-            }
-            m_valid = simul_eq<4, 2>::solve(left, right, m_mtx);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Set the direct transformations, i.e., rectangle -> quadrangle
-        void rect_to_quad(double x1, double y1, double x2, double y2, 
-                          const double* quad)
-        {
-            double src[8];
-            src[0] = src[6] = x1;
-            src[2] = src[4] = x2;
-            src[1] = src[3] = y1;
-            src[5] = src[7] = y2;
-            quad_to_quad(src, quad);
-        }
-
-
-        //--------------------------------------------------------------------
-        // Set the reverse transformations, i.e., quadrangle -> rectangle
-        void quad_to_rect(const double* quad, 
-                          double x1, double y1, double x2, double y2)
-        {
-            double dst[8];
-            dst[0] = dst[6] = x1;
-            dst[2] = dst[4] = x2;
-            dst[1] = dst[3] = y1;
-            dst[5] = dst[7] = y2;
-            quad_to_quad(quad, dst);
-        }
-
-        //--------------------------------------------------------------------
-        // Check if the equations were solved successfully
-        bool is_valid() const { return m_valid; }
-
-        //--------------------------------------------------------------------
-        // Transform a point (x, y)
-        void transform(double* x, double* y) const
-        {
-            double tx = *x;
-            double ty = *y;
-            double xy = tx * ty;
-            *x = m_mtx[0][0] + m_mtx[1][0] * xy + m_mtx[2][0] * tx + m_mtx[3][0] * ty;
-            *y = m_mtx[0][1] + m_mtx[1][1] * xy + m_mtx[2][1] * tx + m_mtx[3][1] * ty;
-        }
-
-
-        //--------------------------------------------------------------------
-        class iterator_x
-        {
-            double inc_x;
-            double inc_y;
-
-        public:
-            double x;
-            double y;
-
-            iterator_x() {}
-            iterator_x(double tx, double ty, double step, const double m[4][2]) :
-                inc_x(m[1][0] * step * ty + m[2][0] * step),
-                inc_y(m[1][1] * step * ty + m[2][1] * step),
-                x(m[0][0] + m[1][0] * tx * ty + m[2][0] * tx + m[3][0] * ty),
-                y(m[0][1] + m[1][1] * tx * ty + m[2][1] * tx + m[3][1] * ty)
-            {
-            }
-
-            void operator ++ ()
-            {
-                x += inc_x;
-                y += inc_y;
-            }
-        };
-
-        iterator_x begin(double x, double y, double step) const
-        {
-            return iterator_x(x, y, step, m_mtx);
-        }
-
-    private:
-        double m_mtx[4][2];
-        bool   m_valid;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_trans_double_path.h b/xs/src/agg/agg_trans_double_path.h
deleted file mode 100644
index c645a7f86..000000000
--- a/xs/src/agg/agg_trans_double_path.h
+++ /dev/null
@@ -1,131 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_TRANS_DOUBLE_PATH_INCLUDED
-#define AGG_TRANS_DOUBLE_PATH_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-    
-    // See also: agg_trans_double_path.cpp
-    //
-    //-------------------------------------------------------trans_double_path
-    class trans_double_path
-    {
-        enum status_e
-        {
-            initial,
-            making_path,
-            ready
-        };
-
-    public:
-        typedef vertex_sequence<vertex_dist, 6> vertex_storage;
-
-        trans_double_path();
-
-        //--------------------------------------------------------------------
-        void   base_length(double v)  { m_base_length = v; }
-        double base_length() const { return m_base_length; }
-
-        //--------------------------------------------------------------------
-        void   base_height(double v)  { m_base_height = v; }
-        double base_height() const { return m_base_height; }
-
-        //--------------------------------------------------------------------
-        void preserve_x_scale(bool f) { m_preserve_x_scale = f;    }
-        bool preserve_x_scale() const { return m_preserve_x_scale; }
-
-        //--------------------------------------------------------------------
-        void reset();
-        void move_to1(double x, double y);
-        void line_to1(double x, double y);
-        void move_to2(double x, double y);
-        void line_to2(double x, double y);
-        void finalize_paths();
-
-        //--------------------------------------------------------------------
-        template<class VertexSource1, class VertexSource2> 
-        void add_paths(VertexSource1& vs1, VertexSource2& vs2, 
-                       unsigned path1_id=0, unsigned path2_id=0)
-        {
-            double x;
-            double y;
-
-            unsigned cmd;
-
-            vs1.rewind(path1_id);
-            while(!is_stop(cmd = vs1.vertex(&x, &y)))
-            {
-                if(is_move_to(cmd)) 
-                {
-                    move_to1(x, y);
-                }
-                else 
-                {
-                    if(is_vertex(cmd))
-                    {
-                        line_to1(x, y);
-                    }
-                }
-            }
-
-            vs2.rewind(path2_id);
-            while(!is_stop(cmd = vs2.vertex(&x, &y)))
-            {
-                if(is_move_to(cmd)) 
-                {
-                    move_to2(x, y);
-                }
-                else 
-                {
-                    if(is_vertex(cmd))
-                    {
-                        line_to2(x, y);
-                    }
-                }
-            }
-            finalize_paths();
-        }
-
-        //--------------------------------------------------------------------
-        double total_length1() const;
-        double total_length2() const;
-        void transform(double *x, double *y) const;
-
-    private:
-        double finalize_path(vertex_storage& vertices);
-        void transform1(const vertex_storage& vertices, 
-                        double kindex, double kx,
-                        double *x, double* y) const;
-
-        vertex_storage m_src_vertices1;
-        vertex_storage m_src_vertices2;
-        double         m_base_length;
-        double         m_base_height;
-        double         m_kindex1;
-        double         m_kindex2;
-        status_e       m_status1;
-        status_e       m_status2;
-        bool           m_preserve_x_scale;
-    };
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_trans_perspective.h b/xs/src/agg/agg_trans_perspective.h
deleted file mode 100644
index 7d4aa26c7..000000000
--- a/xs/src/agg/agg_trans_perspective.h
+++ /dev/null
@@ -1,731 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Perspective 2D transformations
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_TRANS_PERSPECTIVE_INCLUDED
-#define AGG_TRANS_PERSPECTIVE_INCLUDED
-
-#include "agg_trans_affine.h"
-
-namespace agg
-{
-    //=======================================================trans_perspective
-    struct trans_perspective
-    {
-        double sx, shy, w0, shx, sy, w1, tx, ty, w2;
-
-        //------------------------------------------------------- Construction
-        // Identity matrix
-        trans_perspective() : 
-            sx (1), shy(0), w0(0), 
-            shx(0), sy (1), w1(0), 
-            tx (0), ty (0), w2(1) {}
-
-        // Custom matrix
-        trans_perspective(double v0, double v1, double v2, 
-                          double v3, double v4, double v5,
-                          double v6, double v7, double v8) :
-           sx (v0), shy(v1), w0(v2), 
-           shx(v3), sy (v4), w1(v5), 
-           tx (v6), ty (v7), w2(v8) {}
-
-        // Custom matrix from m[9]
-        explicit trans_perspective(const double* m) :
-           sx (m[0]), shy(m[1]), w0(m[2]), 
-           shx(m[3]), sy (m[4]), w1(m[5]), 
-           tx (m[6]), ty (m[7]), w2(m[8]) {}
-
-        // From affine
-        explicit trans_perspective(const trans_affine& a) : 
-           sx (a.sx ), shy(a.shy), w0(0), 
-           shx(a.shx), sy (a.sy ), w1(0), 
-           tx (a.tx ), ty (a.ty ), w2(1) {}
-
-        // Rectangle to quadrilateral
-        trans_perspective(double x1, double y1, double x2, double y2, 
-                          const double* quad);
-
-        // Quadrilateral to rectangle
-        trans_perspective(const double* quad, 
-                          double x1, double y1, double x2, double y2);
-
-        // Arbitrary quadrilateral transformations
-        trans_perspective(const double* src, const double* dst);
-
-        //-------------------------------------- Quadrilateral transformations
-        // The arguments are double[8] that are mapped to quadrilaterals:
-        // x1,y1, x2,y2, x3,y3, x4,y4
-        bool quad_to_quad(const double* qs, const double* qd);
-
-        bool rect_to_quad(double x1, double y1, 
-                          double x2, double y2,
-                          const double* q);
-
-        bool quad_to_rect(const double* q,
-                          double x1, double y1, 
-                          double x2, double y2);
-
-        // Map square (0,0,1,1) to the quadrilateral and vice versa
-        bool square_to_quad(const double* q);
-        bool quad_to_square(const double* q);
-
-
-        //--------------------------------------------------------- Operations
-        // Reset - load an identity matrix
-        const trans_perspective& reset();
-
-        // Invert matrix. Returns false in degenerate case
-        bool invert();
-
-        // Direct transformations operations
-        const trans_perspective& translate(double x, double y);
-        const trans_perspective& rotate(double a);
-        const trans_perspective& scale(double s);
-        const trans_perspective& scale(double x, double y);
-
-        // Multiply the matrix by another one
-        const trans_perspective& multiply(const trans_perspective& m);
-
-        // Multiply "m" by "this" and assign the result to "this"
-        const trans_perspective& premultiply(const trans_perspective& m);
-
-        // Multiply matrix to inverse of another one
-        const trans_perspective& multiply_inv(const trans_perspective& m);
-
-        // Multiply inverse of "m" by "this" and assign the result to "this"
-        const trans_perspective& premultiply_inv(const trans_perspective& m);
-
-        // Multiply the matrix by another one
-        const trans_perspective& multiply(const trans_affine& m);
-
-        // Multiply "m" by "this" and assign the result to "this"
-        const trans_perspective& premultiply(const trans_affine& m);
-
-        // Multiply the matrix by inverse of another one
-        const trans_perspective& multiply_inv(const trans_affine& m);
-
-        // Multiply inverse of "m" by "this" and assign the result to "this"
-        const trans_perspective& premultiply_inv(const trans_affine& m);
-
-        //--------------------------------------------------------- Load/Store
-        void store_to(double* m) const;
-        const trans_perspective& load_from(const double* m);
-
-        //---------------------------------------------------------- Operators
-        // Multiply the matrix by another one
-        const trans_perspective& operator *= (const trans_perspective& m)
-        {
-            return multiply(m);
-        }
-        const trans_perspective& operator *= (const trans_affine& m)
-        {
-            return multiply(m);
-        }
-
-        // Multiply the matrix by inverse of another one
-        const trans_perspective& operator /= (const trans_perspective& m)
-        {
-            return multiply_inv(m);
-        }
-        const trans_perspective& operator /= (const trans_affine& m)
-        {
-            return multiply_inv(m);
-        }
-
-        // Multiply the matrix by another one and return
-        // the result in a separete matrix.
-        trans_perspective operator * (const trans_perspective& m) const
-        {
-            return trans_perspective(*this).multiply(m);
-        }
-        trans_perspective operator * (const trans_affine& m) const
-        {
-            return trans_perspective(*this).multiply(m);
-        }
-
-        // Multiply the matrix by inverse of another one 
-        // and return the result in a separete matrix.
-        trans_perspective operator / (const trans_perspective& m) const
-        {
-            return trans_perspective(*this).multiply_inv(m);
-        }
-        trans_perspective operator / (const trans_affine& m) const
-        {
-            return trans_perspective(*this).multiply_inv(m);
-        }
-
-        // Calculate and return the inverse matrix
-        trans_perspective operator ~ () const
-        {
-            trans_perspective ret = *this;
-            ret.invert();
-            return ret;
-        }
-
-        // Equal operator with default epsilon
-        bool operator == (const trans_perspective& m) const
-        {
-            return is_equal(m, affine_epsilon);
-        }
-
-        // Not Equal operator with default epsilon
-        bool operator != (const trans_perspective& m) const
-        {
-            return !is_equal(m, affine_epsilon);
-        }
-
-        //---------------------------------------------------- Transformations
-        // Direct transformation of x and y
-        void transform(double* x, double* y) const;
-
-        // Direct transformation of x and y, affine part only
-        void transform_affine(double* x, double* y) const;
-
-        // Direct transformation of x and y, 2x2 matrix only, no translation
-        void transform_2x2(double* x, double* y) const;
-
-        // Inverse transformation of x and y. It works slow because
-        // it explicitly inverts the matrix on every call. For massive 
-        // operations it's better to invert() the matrix and then use 
-        // direct transformations. 
-        void inverse_transform(double* x, double* y) const;
-
-
-        //---------------------------------------------------------- Auxiliary
-        const trans_perspective& from_affine(const trans_affine& a);
-        double determinant() const;
-        double determinant_reciprocal() const;
-
-        bool is_valid(double epsilon = affine_epsilon) const;
-        bool is_identity(double epsilon = affine_epsilon) const;
-        bool is_equal(const trans_perspective& m, 
-                      double epsilon = affine_epsilon) const;
-
-        // Determine the major affine parameters. Use with caution 
-        // considering possible degenerate cases.
-        double scale() const;
-        double rotation() const;
-        void   translation(double* dx, double* dy) const;
-        void   scaling(double* x, double* y) const;
-        void   scaling_abs(double* x, double* y) const;
-
-
-
-        //--------------------------------------------------------------------
-        class iterator_x
-        {
-            double den;
-            double den_step;
-            double nom_x;
-            double nom_x_step;
-            double nom_y;
-            double nom_y_step;
-
-        public:
-            double x;
-            double y;
-
-            iterator_x() {}
-            iterator_x(double px, double py, double step, const trans_perspective& m) :
-                den(px * m.w0 + py * m.w1 + m.w2),
-                den_step(m.w0 * step),
-                nom_x(px * m.sx + py * m.shx + m.tx),
-                nom_x_step(step * m.sx),
-                nom_y(px * m.shy + py * m.sy + m.ty),
-                nom_y_step(step * m.shy),
-                x(nom_x / den),
-                y(nom_y / den)
-            {}
-
-            void operator ++ ()
-            {
-                den   += den_step;
-                nom_x += nom_x_step;
-                nom_y += nom_y_step;
-                double d = 1.0 / den;
-                x = nom_x * d;
-                y = nom_y * d;
-            }
-        };
-
-        //--------------------------------------------------------------------
-        iterator_x begin(double x, double y, double step) const
-        {
-            return iterator_x(x, y, step, *this);
-        }
-    };
-
-
-
-
-
-
-
-
-
-   
-
-
-
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::square_to_quad(const double* q)
-    {
-        double dx = q[0] - q[2] + q[4] - q[6];
-        double dy = q[1] - q[3] + q[5] - q[7];
-        if(dx == 0.0 && dy == 0.0)
-        {   
-            // Affine case (parallelogram)
-            //---------------
-            sx  = q[2] - q[0];
-            shy = q[3] - q[1];
-            w0  = 0.0;
-            shx = q[4] - q[2];
-            sy  = q[5] - q[3];
-            w1  = 0.0;
-            tx  = q[0];
-            ty  = q[1];
-            w2  = 1.0;
-        }
-        else
-        {
-            double dx1 = q[2] - q[4];
-            double dy1 = q[3] - q[5];
-            double dx2 = q[6] - q[4];
-            double dy2 = q[7] - q[5];
-            double den = dx1 * dy2 - dx2 * dy1;
-            if(den == 0.0)
-            {
-                // Singular case
-                //---------------
-                sx = shy = w0 = shx = sy = w1 = tx = ty = w2 = 0.0;
-                return false;
-            }
-            // General case
-            //---------------
-            double u = (dx * dy2 - dy * dx2) / den;
-            double v = (dy * dx1 - dx * dy1) / den;
-            sx  = q[2] - q[0] + u * q[2];
-            shy = q[3] - q[1] + u * q[3];
-            w0  = u;
-            shx = q[6] - q[0] + v * q[6];
-            sy  = q[7] - q[1] + v * q[7];
-            w1  = v;
-            tx  = q[0];
-            ty  = q[1];
-            w2  = 1.0;
-        }
-        return true;
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::invert()
-    {
-        double d0 = sy  * w2 - w1  * ty;
-        double d1 = w0  * ty - shy * w2;
-        double d2 = shy * w1 - w0  * sy;
-        double d  = sx  * d0 + shx * d1 + tx * d2;
-        if(d == 0.0) 
-        {
-            sx = shy = w0 = shx = sy = w1 = tx = ty = w2 = 0.0;
-            return false;
-        }
-        d = 1.0 / d;
-        trans_perspective a = *this;
-        sx  = d * d0;
-        shy = d * d1;
-        w0  = d * d2;
-        shx = d * (a.w1 *a.tx  - a.shx*a.w2);
-        sy  = d * (a.sx *a.w2  - a.w0 *a.tx);
-        w1  = d * (a.w0 *a.shx - a.sx *a.w1);
-        tx  = d * (a.shx*a.ty  - a.sy *a.tx);
-        ty  = d * (a.shy*a.tx  - a.sx *a.ty);
-        w2  = d * (a.sx *a.sy  - a.shy*a.shx);
-        return true;
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::quad_to_square(const double* q)
-    {
-        if(!square_to_quad(q)) return false;
-        invert();
-        return true;
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::quad_to_quad(const double* qs, 
-                                                const double* qd)
-    {
-        trans_perspective p;
-        if(!  quad_to_square(qs)) return false;
-        if(!p.square_to_quad(qd)) return false;
-        multiply(p);
-        return true;
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::rect_to_quad(double x1, double y1, 
-                                                double x2, double y2,
-                                                const double* q)
-    {
-        double r[8];
-        r[0] = r[6] = x1;
-        r[2] = r[4] = x2;
-        r[1] = r[3] = y1;
-        r[5] = r[7] = y2;
-        return quad_to_quad(r, q);
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::quad_to_rect(const double* q,
-                                                double x1, double y1, 
-                                                double x2, double y2)
-    {
-        double r[8];
-        r[0] = r[6] = x1;
-        r[2] = r[4] = x2;
-        r[1] = r[3] = y1;
-        r[5] = r[7] = y2;
-        return quad_to_quad(q, r);
-    }
-
-    //------------------------------------------------------------------------
-    inline trans_perspective::trans_perspective(double x1, double y1, 
-                                                double x2, double y2, 
-                                                const double* quad)
-    {
-        rect_to_quad(x1, y1, x2, y2, quad);
-    }
-
-    //------------------------------------------------------------------------
-    inline trans_perspective::trans_perspective(const double* quad, 
-                                                double x1, double y1, 
-                                                double x2, double y2)
-    {
-        quad_to_rect(quad, x1, y1, x2, y2);
-    }
-
-    //------------------------------------------------------------------------
-    inline trans_perspective::trans_perspective(const double* src, 
-                                                const double* dst) 
-    {
-        quad_to_quad(src, dst);
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& trans_perspective::reset()
-    {
-        sx  = 1; shy = 0; w0 = 0; 
-        shx = 0; sy  = 1; w1 = 0;
-        tx  = 0; ty  = 0; w2 = 1;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& 
-    trans_perspective::multiply(const trans_perspective& a)
-    {
-        trans_perspective b = *this;
-        sx  = a.sx *b.sx  + a.shx*b.shy + a.tx*b.w0;
-        shx = a.sx *b.shx + a.shx*b.sy  + a.tx*b.w1;
-        tx  = a.sx *b.tx  + a.shx*b.ty  + a.tx*b.w2;
-        shy = a.shy*b.sx  + a.sy *b.shy + a.ty*b.w0;
-        sy  = a.shy*b.shx + a.sy *b.sy  + a.ty*b.w1;
-        ty  = a.shy*b.tx  + a.sy *b.ty  + a.ty*b.w2;
-        w0  = a.w0 *b.sx  + a.w1 *b.shy + a.w2*b.w0;
-        w1  = a.w0 *b.shx + a.w1 *b.sy  + a.w2*b.w1;
-        w2  = a.w0 *b.tx  + a.w1 *b.ty  + a.w2*b.w2;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& 
-    trans_perspective::multiply(const trans_affine& a)
-    {
-        trans_perspective b = *this;
-        sx  = a.sx *b.sx  + a.shx*b.shy + a.tx*b.w0;
-        shx = a.sx *b.shx + a.shx*b.sy  + a.tx*b.w1;
-        tx  = a.sx *b.tx  + a.shx*b.ty  + a.tx*b.w2;
-        shy = a.shy*b.sx  + a.sy *b.shy + a.ty*b.w0;
-        sy  = a.shy*b.shx + a.sy *b.sy  + a.ty*b.w1;
-        ty  = a.shy*b.tx  + a.sy *b.ty  + a.ty*b.w2;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& 
-    trans_perspective::premultiply(const trans_perspective& b)
-    {
-        trans_perspective a = *this;
-        sx  = a.sx *b.sx  + a.shx*b.shy + a.tx*b.w0;
-        shx = a.sx *b.shx + a.shx*b.sy  + a.tx*b.w1;
-        tx  = a.sx *b.tx  + a.shx*b.ty  + a.tx*b.w2;
-        shy = a.shy*b.sx  + a.sy *b.shy + a.ty*b.w0;
-        sy  = a.shy*b.shx + a.sy *b.sy  + a.ty*b.w1;
-        ty  = a.shy*b.tx  + a.sy *b.ty  + a.ty*b.w2;
-        w0  = a.w0 *b.sx  + a.w1 *b.shy + a.w2*b.w0;
-        w1  = a.w0 *b.shx + a.w1 *b.sy  + a.w2*b.w1;
-        w2  = a.w0 *b.tx  + a.w1 *b.ty  + a.w2*b.w2;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& 
-    trans_perspective::premultiply(const trans_affine& b)
-    {
-        trans_perspective a = *this;
-        sx  = a.sx *b.sx  + a.shx*b.shy;
-        shx = a.sx *b.shx + a.shx*b.sy;
-        tx  = a.sx *b.tx  + a.shx*b.ty  + a.tx;
-        shy = a.shy*b.sx  + a.sy *b.shy;
-        sy  = a.shy*b.shx + a.sy *b.sy;
-        ty  = a.shy*b.tx  + a.sy *b.ty  + a.ty;
-        w0  = a.w0 *b.sx  + a.w1 *b.shy;
-        w1  = a.w0 *b.shx + a.w1 *b.sy;
-        w2  = a.w0 *b.tx  + a.w1 *b.ty  + a.w2;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    const trans_perspective& 
-    trans_perspective::multiply_inv(const trans_perspective& m)
-    {
-        trans_perspective t = m;
-        t.invert();
-        return multiply(t);
-    }
-
-    //------------------------------------------------------------------------
-    const trans_perspective&
-    trans_perspective::multiply_inv(const trans_affine& m)
-    {
-        trans_affine t = m;
-        t.invert();
-        return multiply(t);
-    }
-
-    //------------------------------------------------------------------------
-    const trans_perspective&
-    trans_perspective::premultiply_inv(const trans_perspective& m)
-    {
-        trans_perspective t = m;
-        t.invert();
-        return *this = t.multiply(*this);
-    }
-
-    //------------------------------------------------------------------------
-    const trans_perspective&
-    trans_perspective::premultiply_inv(const trans_affine& m)
-    {
-        trans_perspective t(m);
-        t.invert();
-        return *this = t.multiply(*this);
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& 
-    trans_perspective::translate(double x, double y)
-    {
-        tx += x;
-        ty += y;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& trans_perspective::rotate(double a)
-    {
-        multiply(trans_affine_rotation(a));
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& trans_perspective::scale(double s)
-    {
-        multiply(trans_affine_scaling(s));
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& trans_perspective::scale(double x, double y)
-    {
-        multiply(trans_affine_scaling(x, y));
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline void trans_perspective::transform(double* px, double* py) const
-    {
-        double x = *px;
-        double y = *py;
-        double m = 1.0 / (x*w0 + y*w1 + w2);
-        *px = m * (x*sx  + y*shx + tx);
-        *py = m * (x*shy + y*sy  + ty);
-    }
-
-    //------------------------------------------------------------------------
-    inline void trans_perspective::transform_affine(double* x, double* y) const
-    {
-        double tmp = *x;
-        *x = tmp * sx  + *y * shx + tx;
-        *y = tmp * shy + *y * sy  + ty;
-    }
-
-    //------------------------------------------------------------------------
-    inline void trans_perspective::transform_2x2(double* x, double* y) const
-    {
-        double tmp = *x;
-        *x = tmp * sx  + *y * shx;
-        *y = tmp * shy + *y * sy;
-    }
-
-    //------------------------------------------------------------------------
-    inline void trans_perspective::inverse_transform(double* x, double* y) const
-    {
-        trans_perspective t(*this);
-        if(t.invert()) t.transform(x, y);
-    }
-
-    //------------------------------------------------------------------------
-    inline void trans_perspective::store_to(double* m) const
-    {
-        *m++ = sx;  *m++ = shy; *m++ = w0; 
-        *m++ = shx; *m++ = sy;  *m++ = w1;
-        *m++ = tx;  *m++ = ty;  *m++ = w2;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& trans_perspective::load_from(const double* m)
-    {
-        sx  = *m++; shy = *m++; w0 = *m++; 
-        shx = *m++; sy  = *m++; w1 = *m++;
-        tx  = *m++; ty  = *m++; w2 = *m++;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline const trans_perspective& 
-    trans_perspective::from_affine(const trans_affine& a)
-    {
-        sx  = a.sx;  shy = a.shy; w0 = 0; 
-        shx = a.shx; sy  = a.sy;  w1 = 0;
-        tx  = a.tx;  ty  = a.ty;  w2 = 1;
-        return *this;
-    }
-
-    //------------------------------------------------------------------------
-    inline double trans_perspective::determinant() const
-    {
-        return sx  * (sy  * w2 - ty  * w1) +
-               shx * (ty  * w0 - shy * w2) +
-               tx  * (shy * w1 - sy  * w0);
-    }
-  
-    //------------------------------------------------------------------------
-    inline double trans_perspective::determinant_reciprocal() const
-    {
-        return 1.0 / determinant();
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::is_valid(double epsilon) const
-    {
-        return fabs(sx) > epsilon && fabs(sy) > epsilon && fabs(w2) > epsilon;
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::is_identity(double epsilon) const
-    {
-        return is_equal_eps(sx,  1.0, epsilon) &&
-               is_equal_eps(shy, 0.0, epsilon) &&
-               is_equal_eps(w0,  0.0, epsilon) &&
-               is_equal_eps(shx, 0.0, epsilon) && 
-               is_equal_eps(sy,  1.0, epsilon) &&
-               is_equal_eps(w1,  0.0, epsilon) &&
-               is_equal_eps(tx,  0.0, epsilon) &&
-               is_equal_eps(ty,  0.0, epsilon) &&
-               is_equal_eps(w2,  1.0, epsilon);
-    }
-
-    //------------------------------------------------------------------------
-    inline bool trans_perspective::is_equal(const trans_perspective& m, 
-                                            double epsilon) const
-    {
-        return is_equal_eps(sx,  m.sx,  epsilon) &&
-               is_equal_eps(shy, m.shy, epsilon) &&
-               is_equal_eps(w0,  m.w0,  epsilon) &&
-               is_equal_eps(shx, m.shx, epsilon) && 
-               is_equal_eps(sy,  m.sy,  epsilon) &&
-               is_equal_eps(w1,  m.w1,  epsilon) &&
-               is_equal_eps(tx,  m.tx,  epsilon) &&
-               is_equal_eps(ty,  m.ty,  epsilon) &&
-               is_equal_eps(w2,  m.w2,  epsilon);
-    }
-
-    //------------------------------------------------------------------------
-    inline double trans_perspective::scale() const
-    {
-        double x = 0.707106781 * sx  + 0.707106781 * shx;
-        double y = 0.707106781 * shy + 0.707106781 * sy;
-        return sqrt(x*x + y*y);
-    }
-
-    //------------------------------------------------------------------------
-    inline double trans_perspective::rotation() const
-    {
-        double x1 = 0.0;
-        double y1 = 0.0;
-        double x2 = 1.0;
-        double y2 = 0.0;
-        transform(&x1, &y1);
-        transform(&x2, &y2);
-        return atan2(y2-y1, x2-x1);
-    }
-
-    //------------------------------------------------------------------------
-    void trans_perspective::translation(double* dx, double* dy) const
-    {
-        *dx = tx;
-        *dy = ty;
-    }
-
-    //------------------------------------------------------------------------
-    void trans_perspective::scaling(double* x, double* y) const
-    {
-        double x1 = 0.0;
-        double y1 = 0.0;
-        double x2 = 1.0;
-        double y2 = 1.0;
-        trans_perspective t(*this);
-        t *= trans_affine_rotation(-rotation());
-        t.transform(&x1, &y1);
-        t.transform(&x2, &y2);
-        *x = x2 - x1;
-        *y = y2 - y1;
-    }
-
-    //------------------------------------------------------------------------
-    void trans_perspective::scaling_abs(double* x, double* y) const
-    {
-        *x = sqrt(sx  * sx  + shx * shx);
-        *y = sqrt(shy * shy + sy  * sy);
-    }
-
-
-}
-
-#endif
-
diff --git a/xs/src/agg/agg_trans_single_path.h b/xs/src/agg/agg_trans_single_path.h
deleted file mode 100644
index 9f4bf53bd..000000000
--- a/xs/src/agg/agg_trans_single_path.h
+++ /dev/null
@@ -1,97 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_TRANS_SINGLE_PATH_INCLUDED
-#define AGG_TRANS_SINGLE_PATH_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-
-    // See also: agg_trans_single_path.cpp
-    //
-    //-------------------------------------------------------trans_single_path
-    class trans_single_path
-    {
-        enum status_e
-        {
-            initial,
-            making_path,
-            ready
-        };
-
-    public:
-        typedef vertex_sequence<vertex_dist, 6> vertex_storage;
-
-        trans_single_path();
-
-        //--------------------------------------------------------------------
-        void   base_length(double v)  { m_base_length = v; }
-        double base_length() const { return m_base_length; }
-
-        //--------------------------------------------------------------------
-        void preserve_x_scale(bool f) { m_preserve_x_scale = f;    }
-        bool preserve_x_scale() const { return m_preserve_x_scale; }
-
-        //--------------------------------------------------------------------
-        void reset();
-        void move_to(double x, double y);
-        void line_to(double x, double y);
-        void finalize_path();
-
-        //--------------------------------------------------------------------
-        template<class VertexSource> 
-        void add_path(VertexSource& vs, unsigned path_id=0)
-        {
-            double x;
-            double y;
-
-            unsigned cmd;
-            vs.rewind(path_id);
-            while(!is_stop(cmd = vs.vertex(&x, &y)))
-            {
-                if(is_move_to(cmd)) 
-                {
-                    move_to(x, y);
-                }
-                else 
-                {
-                    if(is_vertex(cmd))
-                    {
-                        line_to(x, y);
-                    }
-                }
-            }
-            finalize_path();
-        }
-
-        //--------------------------------------------------------------------
-        double total_length() const;
-        void transform(double *x, double *y) const;
-
-    private:
-        vertex_storage m_src_vertices;
-        double         m_base_length;
-        double         m_kindex;
-        status_e       m_status;
-        bool           m_preserve_x_scale;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_trans_viewport.h b/xs/src/agg/agg_trans_viewport.h
deleted file mode 100644
index 7088f9907..000000000
--- a/xs/src/agg/agg_trans_viewport.h
+++ /dev/null
@@ -1,303 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Viewport transformer - simple orthogonal conversions from world coordinates
-//                        to screen (device) ones.
-//
-//----------------------------------------------------------------------------
-
-#ifndef AGG_TRANS_VIEWPORT_INCLUDED
-#define AGG_TRANS_VIEWPORT_INCLUDED
-
-#include <string.h>
-#include "agg_trans_affine.h"
-
-
-namespace agg
-{
-
-    enum aspect_ratio_e
-    {
-        aspect_ratio_stretch,
-        aspect_ratio_meet,
-        aspect_ratio_slice
-    };
-
-
-    //----------------------------------------------------------trans_viewport
-    class trans_viewport
-    {
-    public:
-        //-------------------------------------------------------------------
-        trans_viewport() : 
-            m_world_x1(0.0),
-            m_world_y1(0.0),
-            m_world_x2(1.0),
-            m_world_y2(1.0),
-            m_device_x1(0.0),
-            m_device_y1(0.0),
-            m_device_x2(1.0),
-            m_device_y2(1.0),
-            m_aspect(aspect_ratio_stretch),
-            m_is_valid(true),
-            m_align_x(0.5),
-            m_align_y(0.5),
-            m_wx1(0.0),
-            m_wy1(0.0),
-            m_wx2(1.0),
-            m_wy2(1.0),
-            m_dx1(0.0),
-            m_dy1(0.0),
-            m_kx(1.0),
-            m_ky(1.0)
-        {}
-
-        //-------------------------------------------------------------------
-        void preserve_aspect_ratio(double alignx, 
-                                   double aligny, 
-                                   aspect_ratio_e aspect)
-        {
-            m_align_x = alignx;
-            m_align_y = aligny;
-            m_aspect  = aspect;
-            update();
-        }
-
-        //-------------------------------------------------------------------
-        void device_viewport(double x1, double y1, double x2, double y2)
-        {
-            m_device_x1 = x1;
-            m_device_y1 = y1;
-            m_device_x2 = x2;
-            m_device_y2 = y2;
-            update();
-        }
-
-        //-------------------------------------------------------------------
-        void world_viewport(double x1, double y1, double x2, double y2)
-        {
-            m_world_x1 = x1;
-            m_world_y1 = y1;
-            m_world_x2 = x2;
-            m_world_y2 = y2;
-            update();
-        }
-
-        //-------------------------------------------------------------------
-        void device_viewport(double* x1, double* y1, double* x2, double* y2) const
-        {
-            *x1 = m_device_x1;
-            *y1 = m_device_y1;
-            *x2 = m_device_x2;
-            *y2 = m_device_y2;
-        }
-
-        //-------------------------------------------------------------------
-        void world_viewport(double* x1, double* y1, double* x2, double* y2) const
-        {
-            *x1 = m_world_x1;
-            *y1 = m_world_y1;
-            *x2 = m_world_x2;
-            *y2 = m_world_y2;
-        }
-
-        //-------------------------------------------------------------------
-        void world_viewport_actual(double* x1, double* y1, 
-                                   double* x2, double* y2) const
-        {
-            *x1 = m_wx1;
-            *y1 = m_wy1;
-            *x2 = m_wx2;
-            *y2 = m_wy2;
-        }
-
-        //-------------------------------------------------------------------
-        bool   is_valid()             const { return m_is_valid; }
-        double align_x()              const { return m_align_x; }
-        double align_y()              const { return m_align_y; }
-        aspect_ratio_e aspect_ratio() const { return m_aspect; }
-
-        //-------------------------------------------------------------------
-        void transform(double* x, double* y) const
-        {
-            *x = (*x - m_wx1) * m_kx + m_dx1;
-            *y = (*y - m_wy1) * m_ky + m_dy1;
-        }
-
-        //-------------------------------------------------------------------
-        void transform_scale_only(double* x, double* y) const
-        {
-            *x *= m_kx;
-            *y *= m_ky;
-        }
-
-        //-------------------------------------------------------------------
-        void inverse_transform(double* x, double* y) const
-        {
-            *x = (*x - m_dx1) / m_kx + m_wx1;
-            *y = (*y - m_dy1) / m_ky + m_wy1;
-        }
-
-        //-------------------------------------------------------------------
-        void inverse_transform_scale_only(double* x, double* y) const
-        {
-            *x /= m_kx;
-            *y /= m_ky;
-        }
-
-        //-------------------------------------------------------------------
-        double device_dx() const { return m_dx1 - m_wx1 * m_kx; }
-        double device_dy() const { return m_dy1 - m_wy1 * m_ky; }
-
-        //-------------------------------------------------------------------
-        double scale_x() const
-        {
-            return m_kx;
-        }
-
-        //-------------------------------------------------------------------
-        double scale_y() const
-        {
-            return m_ky;
-        }
-
-        //-------------------------------------------------------------------
-        double scale() const
-        {
-            return (m_kx + m_ky) * 0.5;
-        }
-
-        //-------------------------------------------------------------------
-        trans_affine to_affine() const
-        {
-            trans_affine mtx = trans_affine_translation(-m_wx1, -m_wy1);
-            mtx *= trans_affine_scaling(m_kx, m_ky);
-            mtx *= trans_affine_translation(m_dx1, m_dy1);
-            return mtx;
-        }
-
-        //-------------------------------------------------------------------
-        trans_affine to_affine_scale_only() const
-        {
-            return trans_affine_scaling(m_kx, m_ky);
-        }
-
-        //-------------------------------------------------------------------
-        unsigned byte_size() const
-        {
-            return sizeof(*this);
-        }
-
-        void serialize(int8u* ptr) const
-        {
-            memcpy(ptr, this, sizeof(*this)); 
-        }
-
-        void deserialize(const int8u* ptr)
-        {
-            memcpy(this,  ptr, sizeof(*this));
-        }
-
-    private:
-        void update();
-
-        double         m_world_x1;
-        double         m_world_y1;
-        double         m_world_x2;
-        double         m_world_y2;
-        double         m_device_x1;
-        double         m_device_y1;
-        double         m_device_x2;
-        double         m_device_y2;
-        aspect_ratio_e m_aspect;
-        bool           m_is_valid;
-        double         m_align_x;
-        double         m_align_y;
-        double         m_wx1;
-        double         m_wy1;
-        double         m_wx2;
-        double         m_wy2;
-        double         m_dx1;
-        double         m_dy1;
-        double         m_kx;
-        double         m_ky;
-    };
-
-
-
-    //-----------------------------------------------------------------------
-    inline void trans_viewport::update()
-    {
-        const double epsilon = 1e-30;
-        if(fabs(m_world_x1  - m_world_x2)  < epsilon ||
-           fabs(m_world_y1  - m_world_y2)  < epsilon ||
-           fabs(m_device_x1 - m_device_x2) < epsilon ||
-           fabs(m_device_y1 - m_device_y2) < epsilon)
-        {
-            m_wx1 = m_world_x1;
-            m_wy1 = m_world_y1;
-            m_wx2 = m_world_x1 + 1.0;
-            m_wy2 = m_world_y2 + 1.0;
-            m_dx1 = m_device_x1;
-            m_dy1 = m_device_y1;
-            m_kx  = 1.0;
-            m_ky  = 1.0;
-            m_is_valid = false;
-            return;
-        }
-
-        double world_x1  = m_world_x1;
-        double world_y1  = m_world_y1;
-        double world_x2  = m_world_x2;
-        double world_y2  = m_world_y2;
-        double device_x1 = m_device_x1;
-        double device_y1 = m_device_y1;
-        double device_x2 = m_device_x2;
-        double device_y2 = m_device_y2;
-        if(m_aspect != aspect_ratio_stretch)
-        {
-            double d;
-            m_kx = (device_x2 - device_x1) / (world_x2 - world_x1);
-            m_ky = (device_y2 - device_y1) / (world_y2 - world_y1);
-
-            if((m_aspect == aspect_ratio_meet) == (m_kx < m_ky))
-            {
-                d         = (world_y2 - world_y1) * m_ky / m_kx;
-                world_y1 += (world_y2 - world_y1 - d) * m_align_y;
-                world_y2  =  world_y1 + d;
-            }
-            else
-            {
-                d         = (world_x2 - world_x1) * m_kx / m_ky;
-                world_x1 += (world_x2 - world_x1 - d) * m_align_x;
-                world_x2  =  world_x1 + d;
-            }
-        }
-        m_wx1 = world_x1;
-        m_wy1 = world_y1;
-        m_wx2 = world_x2;
-        m_wy2 = world_y2;
-        m_dx1 = device_x1;
-        m_dy1 = device_y1;
-        m_kx  = (device_x2 - device_x1) / (world_x2 - world_x1);
-        m_ky  = (device_y2 - device_y1) / (world_y2 - world_y1);
-        m_is_valid = true;
-    }
-
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_trans_warp_magnifier.h b/xs/src/agg/agg_trans_warp_magnifier.h
deleted file mode 100644
index 38a92dbec..000000000
--- a/xs/src/agg/agg_trans_warp_magnifier.h
+++ /dev/null
@@ -1,56 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_WARP_MAGNIFIER_INCLUDED
-#define AGG_WARP_MAGNIFIER_INCLUDED
-
-
-namespace agg
-{
-
-    //----------------------------------------------------trans_warp_magnifier
-    //
-    // See Inmplementation agg_trans_warp_magnifier.cpp
-    //
-    class trans_warp_magnifier
-    {
-    public:
-        trans_warp_magnifier() : m_xc(0.0), m_yc(0.0), m_magn(1.0), m_radius(1.0) {}
- 
-        void center(double x, double y) { m_xc = x; m_yc = y; }
-        void magnification(double m)    { m_magn = m;         }
-        void radius(double r)           { m_radius = r;       }
-
-        double xc()            const { return m_xc; }
-        double yc()            const { return m_yc; }
-        double magnification() const { return m_magn;   }
-        double radius()        const { return m_radius; }
-
-        void transform(double* x, double* y) const;
-        void inverse_transform(double* x, double* y) const;
-
-    private:
-        double m_xc;
-        double m_yc;
-        double m_magn;
-        double m_radius;
-    };
-
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_vcgen_bspline.h b/xs/src/agg/agg_vcgen_bspline.h
deleted file mode 100644
index a2944548c..000000000
--- a/xs/src/agg/agg_vcgen_bspline.h
+++ /dev/null
@@ -1,74 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VCGEN_BSPLINE_INCLUDED
-#define AGG_VCGEN_BSPLINE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_array.h"
-#include "agg_bspline.h"
-
-
-namespace agg
-{
-
-    //==========================================================vcgen_bspline
-    class vcgen_bspline
-    {
-        enum status_e
-        {
-            initial,
-            ready,
-            polygon,
-            end_poly,
-            stop
-        };
-
-    public:
-        typedef pod_bvector<point_d, 6> vertex_storage;
-
-        vcgen_bspline();
-
-        void interpolation_step(double v) { m_interpolation_step = v; }
-        double interpolation_step() const { return m_interpolation_step; }
-
-        // Vertex Generator Interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        vcgen_bspline(const vcgen_bspline&);
-        const vcgen_bspline& operator = (const vcgen_bspline&);
-
-        vertex_storage m_src_vertices;
-        bspline        m_spline_x;
-        bspline        m_spline_y;
-        double         m_interpolation_step;
-        unsigned       m_closed;
-        status_e       m_status;
-        unsigned       m_src_vertex;
-        double         m_cur_abscissa;
-        double         m_max_abscissa;
-    };
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_vcgen_contour.h b/xs/src/agg/agg_vcgen_contour.h
deleted file mode 100644
index 8c25da13f..000000000
--- a/xs/src/agg/agg_vcgen_contour.h
+++ /dev/null
@@ -1,94 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VCGEN_CONTOUR_INCLUDED
-#define AGG_VCGEN_CONTOUR_INCLUDED
-
-#include "agg_math_stroke.h"
-
-namespace agg
-{
-
-    //----------------------------------------------------------vcgen_contour
-    //
-    // See Implementation agg_vcgen_contour.cpp
-    //
-    class vcgen_contour
-    {
-        enum status_e
-        {
-            initial,
-            ready,
-            outline,
-            out_vertices,
-            end_poly,
-            stop
-        };
-
-    public:
-        typedef vertex_sequence<vertex_dist, 6> vertex_storage;
-        typedef pod_bvector<point_d, 6>         coord_storage;
-
-        vcgen_contour();
-
-        void line_cap(line_cap_e lc)     { m_stroker.line_cap(lc); }
-        void line_join(line_join_e lj)   { m_stroker.line_join(lj); }
-        void inner_join(inner_join_e ij) { m_stroker.inner_join(ij); }
-
-        line_cap_e   line_cap()   const { return m_stroker.line_cap(); }
-        line_join_e  line_join()  const { return m_stroker.line_join(); }
-        inner_join_e inner_join() const { return m_stroker.inner_join(); }
-
-        void width(double w) { m_stroker.width(m_width = w); }
-        void miter_limit(double ml) { m_stroker.miter_limit(ml); }
-        void miter_limit_theta(double t) { m_stroker.miter_limit_theta(t); }
-        void inner_miter_limit(double ml) { m_stroker.inner_miter_limit(ml); }
-        void approximation_scale(double as) { m_stroker.approximation_scale(as); }
-
-        double width() const { return m_width; }
-        double miter_limit() const { return m_stroker.miter_limit(); }
-        double inner_miter_limit() const { return m_stroker.inner_miter_limit(); }
-        double approximation_scale() const { return m_stroker.approximation_scale(); }
-
-        void auto_detect_orientation(bool v) { m_auto_detect = v; }
-        bool auto_detect_orientation() const { return m_auto_detect; }
-
-        // Generator interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        vcgen_contour(const vcgen_contour&);
-        const vcgen_contour& operator = (const vcgen_contour&);
-
-        math_stroke<coord_storage> m_stroker;
-        double                     m_width;
-        vertex_storage             m_src_vertices;
-        coord_storage              m_out_vertices;
-        status_e                   m_status;
-        unsigned                   m_src_vertex;
-        unsigned                   m_out_vertex;
-        unsigned                   m_closed;
-        unsigned                   m_orientation;
-        bool                       m_auto_detect;
-    };
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_vcgen_dash.h b/xs/src/agg/agg_vcgen_dash.h
deleted file mode 100644
index c87dce4c8..000000000
--- a/xs/src/agg/agg_vcgen_dash.h
+++ /dev/null
@@ -1,93 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// Line dash generator
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_VCGEN_DASH_INCLUDED
-#define AGG_VCGEN_DASH_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-
-    //---------------------------------------------------------------vcgen_dash
-    //
-    // See Implementation agg_vcgen_dash.cpp
-    //
-    class vcgen_dash
-    {
-        enum max_dashes_e
-        {
-            max_dashes = 32
-        };
-
-        enum status_e
-        {
-            initial,
-            ready,
-            polyline,
-            stop
-        };
-
-    public:
-        typedef vertex_sequence<vertex_dist, 6> vertex_storage;
-
-        vcgen_dash();
-
-        void remove_all_dashes();
-        void add_dash(double dash_len, double gap_len);
-        void dash_start(double ds);
-
-        void shorten(double s) { m_shorten = s; }
-        double shorten() const { return m_shorten; }
-
-        // Vertex Generator Interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        vcgen_dash(const vcgen_dash&);
-        const vcgen_dash& operator = (const vcgen_dash&);
-
-        void calc_dash_start(double ds);
-
-        double             m_dashes[max_dashes];
-        double             m_total_dash_len;
-        unsigned           m_num_dashes;
-        double             m_dash_start;
-        double             m_shorten;
-        double             m_curr_dash_start;
-        unsigned           m_curr_dash;
-        double             m_curr_rest;
-        const vertex_dist* m_v1;
-        const vertex_dist* m_v2;
-
-        vertex_storage m_src_vertices;
-        unsigned       m_closed;
-        status_e       m_status;
-        unsigned       m_src_vertex;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_vcgen_markers_term.h b/xs/src/agg/agg_vcgen_markers_term.h
deleted file mode 100644
index ee1e74e3e..000000000
--- a/xs/src/agg/agg_vcgen_markers_term.h
+++ /dev/null
@@ -1,66 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VCGEN_MARKERS_TERM_INCLUDED
-#define AGG_VCGEN_MARKERS_TERM_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-
-namespace agg
-{
-
-    //======================================================vcgen_markers_term
-    //
-    // See Implemantation agg_vcgen_markers_term.cpp
-    // Terminal markers generator (arrowhead/arrowtail)
-    //
-    //------------------------------------------------------------------------
-    class vcgen_markers_term
-    {
-    public:
-        vcgen_markers_term() : m_curr_id(0), m_curr_idx(0) {}
-
-        // Vertex Generator Interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        vcgen_markers_term(const vcgen_markers_term&);
-        const vcgen_markers_term& operator = (const vcgen_markers_term&);
-
-        struct coord_type
-        {
-            double x, y;
-
-            coord_type() {}
-            coord_type(double x_, double y_) : x(x_), y(y_) {}
-        };
-
-        typedef pod_bvector<coord_type, 6> coord_storage; 
-
-        coord_storage m_markers;
-        unsigned      m_curr_id;
-        unsigned      m_curr_idx;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_vcgen_smooth_poly1.h b/xs/src/agg/agg_vcgen_smooth_poly1.h
deleted file mode 100644
index 80fc0fb79..000000000
--- a/xs/src/agg/agg_vcgen_smooth_poly1.h
+++ /dev/null
@@ -1,87 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VCGEN_SMOOTH_POLY1_INCLUDED
-#define AGG_VCGEN_SMOOTH_POLY1_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-
-
-namespace agg
-{
-
-    //======================================================vcgen_smooth_poly1
-    //
-    // See Implementation agg_vcgen_smooth_poly1.cpp 
-    // Smooth polygon generator
-    //
-    //------------------------------------------------------------------------
-    class vcgen_smooth_poly1
-    {
-        enum status_e
-        {
-            initial,
-            ready,
-            polygon,
-            ctrl_b,
-            ctrl_e,
-            ctrl1,
-            ctrl2,
-            end_poly,
-            stop
-        };
-
-    public:
-        typedef vertex_sequence<vertex_dist, 6> vertex_storage;
-
-        vcgen_smooth_poly1();
-
-        void   smooth_value(double v) { m_smooth_value = v * 0.5; }
-        double smooth_value() const { return m_smooth_value * 2.0; }
-
-        // Vertex Generator Interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        vcgen_smooth_poly1(const vcgen_smooth_poly1&);
-        const vcgen_smooth_poly1& operator = (const vcgen_smooth_poly1&);
-
-        void calculate(const vertex_dist& v0, 
-                       const vertex_dist& v1, 
-                       const vertex_dist& v2,
-                       const vertex_dist& v3);
-
-        vertex_storage m_src_vertices;
-        double         m_smooth_value;
-        unsigned       m_closed;
-        status_e       m_status;
-        unsigned       m_src_vertex;
-        double         m_ctrl1_x;
-        double         m_ctrl1_y;
-        double         m_ctrl2_x;
-        double         m_ctrl2_y;
-    };
-
-}
-
-
-#endif
-
diff --git a/xs/src/agg/agg_vcgen_stroke.h b/xs/src/agg/agg_vcgen_stroke.h
deleted file mode 100644
index 778223fe4..000000000
--- a/xs/src/agg/agg_vcgen_stroke.h
+++ /dev/null
@@ -1,102 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VCGEN_STROKE_INCLUDED
-#define AGG_VCGEN_STROKE_INCLUDED
-
-#include "agg_math_stroke.h"
-
-
-namespace agg
-{
-
-    //============================================================vcgen_stroke
-    //
-    // See Implementation agg_vcgen_stroke.cpp
-    // Stroke generator
-    //
-    //------------------------------------------------------------------------
-    class vcgen_stroke
-    {
-        enum status_e
-        {
-            initial,
-            ready,
-            cap1,
-            cap2,
-            outline1,
-            close_first,
-            outline2,
-            out_vertices,
-            end_poly1,
-            end_poly2,
-            stop
-        };
-
-    public:
-        typedef vertex_sequence<vertex_dist, 6> vertex_storage;
-        typedef pod_bvector<point_d, 6>         coord_storage;
-
-        vcgen_stroke();
-
-        void line_cap(line_cap_e lc)     { m_stroker.line_cap(lc); }
-        void line_join(line_join_e lj)   { m_stroker.line_join(lj); }
-        void inner_join(inner_join_e ij) { m_stroker.inner_join(ij); }
-
-        line_cap_e   line_cap()   const { return m_stroker.line_cap(); }
-        line_join_e  line_join()  const { return m_stroker.line_join(); }
-        inner_join_e inner_join() const { return m_stroker.inner_join(); }
-
-        void width(double w) { m_stroker.width(w); }
-        void miter_limit(double ml) { m_stroker.miter_limit(ml); }
-        void miter_limit_theta(double t) { m_stroker.miter_limit_theta(t); }
-        void inner_miter_limit(double ml) { m_stroker.inner_miter_limit(ml); }
-        void approximation_scale(double as) { m_stroker.approximation_scale(as); }
-
-        double width() const { return m_stroker.width(); }
-        double miter_limit() const { return m_stroker.miter_limit(); }
-        double inner_miter_limit() const { return m_stroker.inner_miter_limit(); }
-        double approximation_scale() const { return m_stroker.approximation_scale(); }
-
-        void shorten(double s) { m_shorten = s; }
-        double shorten() const { return m_shorten; }
-
-        // Vertex Generator Interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        vcgen_stroke(const vcgen_stroke&);
-        const vcgen_stroke& operator = (const vcgen_stroke&);
-
-        math_stroke<coord_storage> m_stroker;
-        vertex_storage             m_src_vertices;
-        coord_storage              m_out_vertices;
-        double                     m_shorten;
-        unsigned                   m_closed;
-        status_e                   m_status;
-        status_e                   m_prev_status;
-        unsigned                   m_src_vertex;
-        unsigned                   m_out_vertex;
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_vcgen_vertex_sequence.h b/xs/src/agg/agg_vcgen_vertex_sequence.h
deleted file mode 100644
index 5adc67159..000000000
--- a/xs/src/agg/agg_vcgen_vertex_sequence.h
+++ /dev/null
@@ -1,135 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VCGEN_VERTEX_SEQUENCE_INCLUDED
-#define AGG_VCGEN_VERTEX_SEQUENCE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_vertex_sequence.h"
-#include "agg_shorten_path.h"
-
-namespace agg
-{
-
-    //===================================================vcgen_vertex_sequence
-    class vcgen_vertex_sequence
-    {
-    public:
-        typedef vertex_dist_cmd                 vertex_type;
-        typedef vertex_sequence<vertex_type, 6> vertex_storage;
-
-        vcgen_vertex_sequence() :
-            m_flags(0),
-            m_cur_vertex(0),
-            m_shorten(0.0),
-            m_ready(false)
-        {
-        }
-
-        // Vertex Generator Interface
-        void remove_all();
-        void add_vertex(double x, double y, unsigned cmd);
-
-        // Vertex Source Interface
-        void     rewind(unsigned path_id);
-        unsigned vertex(double* x, double* y);
-
-        void shorten(double s) { m_shorten = s; }
-        double shorten() const { return m_shorten; }
-
-    private:
-        vcgen_vertex_sequence(const vcgen_vertex_sequence&);
-        const vcgen_vertex_sequence& operator = (const vcgen_vertex_sequence&);
-
-        vertex_storage m_src_vertices;
-        unsigned       m_flags;
-        unsigned       m_cur_vertex;
-        double         m_shorten;
-        bool           m_ready;
-    };
-
-
-    //------------------------------------------------------------------------
-    inline void vcgen_vertex_sequence::remove_all()
-    {
-        m_ready = false;
-        m_src_vertices.remove_all();
-        m_cur_vertex = 0;
-        m_flags = 0;
-    }
-
-    //------------------------------------------------------------------------
-    inline void vcgen_vertex_sequence::add_vertex(double x, double y, unsigned cmd)
-    {
-        m_ready = false;
-        if(is_move_to(cmd))
-        {
-            m_src_vertices.modify_last(vertex_dist_cmd(x, y, cmd));
-        }
-        else
-        {
-            if(is_vertex(cmd))
-            {
-                m_src_vertices.add(vertex_dist_cmd(x, y, cmd));
-            }
-            else
-            {
-                m_flags = cmd & path_flags_mask;
-            }
-        }
-    }
-
-
-    //------------------------------------------------------------------------
-    inline void vcgen_vertex_sequence::rewind(unsigned) 
-    { 
-        if(!m_ready)
-        {
-            m_src_vertices.close(is_closed(m_flags));
-            shorten_path(m_src_vertices, m_shorten, get_close_flag(m_flags));
-        }
-        m_ready = true;
-        m_cur_vertex = 0; 
-    }
-
-    //------------------------------------------------------------------------
-    inline unsigned vcgen_vertex_sequence::vertex(double* x, double* y)
-    {
-        if(!m_ready)
-        {
-            rewind(0);
-        }
-
-        if(m_cur_vertex == m_src_vertices.size())
-        {
-            ++m_cur_vertex;
-            return path_cmd_end_poly | m_flags;
-        }
-
-        if(m_cur_vertex > m_src_vertices.size())
-        {
-            return path_cmd_stop;
-        }
-
-        vertex_type& v = m_src_vertices[m_cur_vertex++];
-        *x = v.x;
-        *y = v.y;
-        return v.cmd;
-    }
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_vertex_sequence.h b/xs/src/agg/agg_vertex_sequence.h
deleted file mode 100644
index 2ad0701b3..000000000
--- a/xs/src/agg/agg_vertex_sequence.h
+++ /dev/null
@@ -1,172 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-//
-// vertex_sequence container and vertex_dist struct
-//
-//----------------------------------------------------------------------------
-#ifndef AGG_VERTEX_SEQUENCE_INCLUDED
-#define AGG_VERTEX_SEQUENCE_INCLUDED
-
-#include "agg_basics.h"
-#include "agg_array.h"
-#include "agg_math.h"
-
-namespace agg
-{
-
-    //----------------------------------------------------------vertex_sequence
-    // Modified agg::pod_bvector. The data is interpreted as a sequence 
-    // of vertices. It means that the type T must expose:
-    //
-    // bool T::operator() (const T& val)
-    // 
-    // that is called every time new vertex is being added. The main purpose
-    // of this operator is the possibility to calculate some values during 
-    // adding and to return true if the vertex fits some criteria or false if
-    // it doesn't. In the last case the new vertex is not added. 
-    // 
-    // The simple example is filtering coinciding vertices with calculation 
-    // of the distance between the current and previous ones:
-    //
-    //    struct vertex_dist
-    //    {
-    //        double   x;
-    //        double   y;
-    //        double   dist;
-    //
-    //        vertex_dist() {}
-    //        vertex_dist(double x_, double y_) :
-    //            x(x_),
-    //            y(y_),
-    //            dist(0.0)
-    //        {
-    //        }
-    //
-    //        bool operator () (const vertex_dist& val)
-    //        {
-    //            return (dist = calc_distance(x, y, val.x, val.y)) > EPSILON;
-    //        }
-    //    };
-    //
-    // Function close() calls this operator and removes the last vertex if 
-    // necessary.
-    //------------------------------------------------------------------------
-    template<class T, unsigned S=6> 
-    class vertex_sequence : public pod_bvector<T, S>
-    {
-    public:
-        typedef pod_bvector<T, S> base_type;
-
-        void add(const T& val);
-        void modify_last(const T& val);
-        void close(bool remove_flag);
-    };
-
-
-
-    //------------------------------------------------------------------------
-    template<class T, unsigned S> 
-    void vertex_sequence<T, S>::add(const T& val)
-    {
-        if(base_type::size() > 1)
-        {
-            if(!(*this)[base_type::size() - 2]((*this)[base_type::size() - 1])) 
-            {
-                base_type::remove_last();
-            }
-        }
-        base_type::add(val);
-    }
-
-
-    //------------------------------------------------------------------------
-    template<class T, unsigned S> 
-    void vertex_sequence<T, S>::modify_last(const T& val)
-    {
-        base_type::remove_last();
-        add(val);
-    }
-
-
-
-    //------------------------------------------------------------------------
-    template<class T, unsigned S> 
-    void vertex_sequence<T, S>::close(bool closed)
-    {
-        while(base_type::size() > 1)
-        {
-            if((*this)[base_type::size() - 2]((*this)[base_type::size() - 1])) break;
-            T t = (*this)[base_type::size() - 1];
-            base_type::remove_last();
-            modify_last(t);
-        }
-
-        if(closed)
-        {
-            while(base_type::size() > 1)
-            {
-                if((*this)[base_type::size() - 1]((*this)[0])) break;
-                base_type::remove_last();
-            }
-        }
-    }
-
-
-    //-------------------------------------------------------------vertex_dist
-    // Vertex (x, y) with the distance to the next one. The last vertex has 
-    // distance between the last and the first points if the polygon is closed
-    // and 0.0 if it's a polyline.
-    struct vertex_dist
-    {
-        double   x;
-        double   y;
-        double   dist;
-
-        vertex_dist() {}
-        vertex_dist(double x_, double y_) :
-            x(x_),
-            y(y_),
-            dist(0.0)
-        {
-        }
-
-        bool operator () (const vertex_dist& val)
-        {
-            bool ret = (dist = calc_distance(x, y, val.x, val.y)) > vertex_dist_epsilon;
-            if(!ret) dist = 1.0 / vertex_dist_epsilon;
-            return ret;
-        }
-    };
-
-
-
-    //--------------------------------------------------------vertex_dist_cmd
-    // Save as the above but with additional "command" value
-    struct vertex_dist_cmd : public vertex_dist
-    {
-        unsigned cmd;
-
-        vertex_dist_cmd() {}
-        vertex_dist_cmd(double x_, double y_, unsigned cmd_) :
-            vertex_dist(x_, y_),
-            cmd(cmd_)
-        {
-        }
-    };
-
-
-}
-
-#endif
diff --git a/xs/src/agg/agg_vpgen_clip_polygon.h b/xs/src/agg/agg_vpgen_clip_polygon.h
deleted file mode 100644
index ded754e21..000000000
--- a/xs/src/agg/agg_vpgen_clip_polygon.h
+++ /dev/null
@@ -1,83 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VPGEN_CLIP_POLYGON_INCLUDED
-#define AGG_VPGEN_CLIP_POLYGON_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //======================================================vpgen_clip_polygon
-    //
-    // See Implementation agg_vpgen_clip_polygon.cpp
-    //
-    class vpgen_clip_polygon
-    {
-    public:
-        vpgen_clip_polygon() : 
-            m_clip_box(0, 0, 1, 1),
-            m_x1(0),
-            m_y1(0),
-            m_clip_flags(0),
-            m_num_vertices(0),
-            m_vertex(0),
-            m_cmd(path_cmd_move_to)
-        {
-        }
-
-        void clip_box(double x1, double y1, double x2, double y2)
-        {
-            m_clip_box.x1 = x1;
-            m_clip_box.y1 = y1;
-            m_clip_box.x2 = x2;
-            m_clip_box.y2 = y2;
-            m_clip_box.normalize();
-        }
-
-
-        double x1() const { return m_clip_box.x1; }
-        double y1() const { return m_clip_box.y1; }
-        double x2() const { return m_clip_box.x2; }
-        double y2() const { return m_clip_box.y2; }
-
-        static bool auto_close()   { return true;  }
-        static bool auto_unclose() { return false; }
-
-        void     reset();
-        void     move_to(double x, double y);
-        void     line_to(double x, double y);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        unsigned clipping_flags(double x, double y);
-
-    private:
-        rect_d        m_clip_box;
-        double        m_x1;
-        double        m_y1;
-        unsigned      m_clip_flags;
-        double        m_x[4];
-        double        m_y[4];
-        unsigned      m_num_vertices;
-        unsigned      m_vertex;
-        unsigned      m_cmd;
-    };
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_vpgen_clip_polyline.h b/xs/src/agg/agg_vpgen_clip_polyline.h
deleted file mode 100644
index b070a7759..000000000
--- a/xs/src/agg/agg_vpgen_clip_polyline.h
+++ /dev/null
@@ -1,78 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VPGEN_CLIP_POLYLINE_INCLUDED
-#define AGG_VPGEN_CLIP_POLYLINE_INCLUDED
-
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //======================================================vpgen_clip_polyline
-    //
-    // See Implementation agg_vpgen_clip_polyline.cpp
-    //
-    class vpgen_clip_polyline
-    {
-    public:
-        vpgen_clip_polyline() : 
-            m_clip_box(0, 0, 1, 1),
-            m_x1(0),
-            m_y1(0),
-            m_num_vertices(0),
-            m_vertex(0),
-            m_move_to(false)
-        {
-        }
-
-        void clip_box(double x1, double y1, double x2, double y2)
-        {
-            m_clip_box.x1 = x1;
-            m_clip_box.y1 = y1;
-            m_clip_box.x2 = x2;
-            m_clip_box.y2 = y2;
-            m_clip_box.normalize();
-        }
-
-        double x1() const { return m_clip_box.x1; }
-        double y1() const { return m_clip_box.y1; }
-        double x2() const { return m_clip_box.x2; }
-        double y2() const { return m_clip_box.y2; }
-
-        static bool auto_close()   { return false; }
-        static bool auto_unclose() { return true; }
-
-        void     reset();
-        void     move_to(double x, double y);
-        void     line_to(double x, double y);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        rect_d        m_clip_box;
-        double        m_x1;
-        double        m_y1;
-        double        m_x[2];
-        double        m_y[2];
-        unsigned      m_cmd[2];
-        unsigned      m_num_vertices;
-        unsigned      m_vertex;
-        bool          m_move_to;
-    };
-
-}
-
-
-#endif
diff --git a/xs/src/agg/agg_vpgen_segmentator.h b/xs/src/agg/agg_vpgen_segmentator.h
deleted file mode 100644
index 29b3c9fa6..000000000
--- a/xs/src/agg/agg_vpgen_segmentator.h
+++ /dev/null
@@ -1,61 +0,0 @@
-//----------------------------------------------------------------------------
-// Anti-Grain Geometry - Version 2.4
-// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
-//
-// Permission to copy, use, modify, sell and distribute this software 
-// is granted provided this copyright notice appears in all copies. 
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
-//
-//----------------------------------------------------------------------------
-// Contact: mcseem@antigrain.com
-//          mcseemagg@yahoo.com
-//          http://www.antigrain.com
-//----------------------------------------------------------------------------
-
-#ifndef AGG_VPGEN_SEGMENTATOR_INCLUDED
-#define AGG_VPGEN_SEGMENTATOR_INCLUDED
-
-#include <math.h>
-#include "agg_basics.h"
-
-namespace agg
-{
-
-    //=======================================================vpgen_segmentator
-    // 
-    // See Implementation agg_vpgen_segmentator.cpp
-    //
-    class vpgen_segmentator
-    {
-    public:
-        vpgen_segmentator() : m_approximation_scale(1.0) {}
-
-        void approximation_scale(double s) { m_approximation_scale = s;     }
-        double approximation_scale() const { return m_approximation_scale;  }
-
-        static bool auto_close()   { return false; }
-        static bool auto_unclose() { return false; }
-
-        void reset() { m_cmd = path_cmd_stop; }
-        void move_to(double x, double y);
-        void line_to(double x, double y);
-        unsigned vertex(double* x, double* y);
-
-    private:
-        double   m_approximation_scale;
-        double   m_x1;
-        double   m_y1;
-        double   m_dx;
-        double   m_dy;
-        double   m_dl;
-        double   m_ddl;
-        unsigned m_cmd;
-    };
-
-
-
-}
-
-#endif
-
diff --git a/xs/src/libslic3r/Rasterizer/Rasterizer.cpp b/xs/src/libslic3r/Rasterizer/Rasterizer.cpp
index adf4fa2c8..71d0c8ef3 100644
--- a/xs/src/libslic3r/Rasterizer/Rasterizer.cpp
+++ b/xs/src/libslic3r/Rasterizer/Rasterizer.cpp
@@ -9,7 +9,6 @@
 #include <agg/agg_pixfmt_gray.h>
 #include <agg/agg_pixfmt_rgb.h>
 #include <agg/agg_renderer_base.h>
-#include <agg/agg_renderer_primitives.h>
 #include <agg/agg_renderer_scanline.h>
 
 #include <agg/agg_scanline_p.h>
diff --git a/xs/src/png/AUTHORS b/xs/src/png/AUTHORS
new file mode 100644
index 000000000..25aad54dc
--- /dev/null
+++ b/xs/src/png/AUTHORS
@@ -0,0 +1,4 @@
+png++ is written by Alexander Shulgin  (alex dot shulgin at gmail dot com)
+Copyright (C) 2007,2008
+
+When writing to me be sure to put png++: in the subject :-)
diff --git a/xs/src/png/NEWS b/xs/src/png/NEWS
new file mode 100644
index 000000000..cc006fbf5
--- /dev/null
+++ b/xs/src/png/NEWS
@@ -0,0 +1,60 @@
+Version 0.2.7:
+
+  - Added solid_pixel_buffer (patch by Andrey Potapov).
+
+  - Fixed some compilation problems on Win32.
+
+Version 0.2.5:
+
+  - Fixed compatibility with newer libpng versions (>= 1.4)
+
+  - Fixed compilation on FreeBSD.
+
+  - Fixed tRNS handling with transformations.
+
+  - Added IO transformation debugging facility.
+
+  - Better organized test suite.
+
+Version 0.2.3:
+
+  - Fixed numerous `already defined' errors due to require_color_space
+    implementation.
+
+  - Added `config.hpp'.
+
+  - Fixed `strerror' usage.
+
+  - Minor docs fixes.
+
+
+Version 0.2.1:
+
+  - Added support for tRNS chunk.
+
+  - Added non-std IO streams support.
+
+  - Fixed 16-bit endianness problems.
+
+  - Improved test script.
+
+
+Version 0.2.0:
+
+  - Added support for 16-bit data (RGB, RGBA, Grayscale and Gray+Alpha
+    color types)
+
+  - Added support for packed 1-, 2- or 4-bit pixels (Grayscale and
+    Indexed colors)
+
+  - Fixed interlace handling code which was severely broken
+
+  - Added possibility to process images without reading the entire
+    image into memory
+
+  - Internals are refactored while the client interface is mostly
+    unchanged
+
+  - Added intensive test suite
+
+  - Added documentation
diff --git a/xs/src/png/libpng/ANNOUNCE b/xs/src/png/libpng/ANNOUNCE
new file mode 100644
index 000000000..0f66c0d1d
--- /dev/null
+++ b/xs/src/png/libpng/ANNOUNCE
@@ -0,0 +1,35 @@
+Libpng 1.6.34 - September 29, 2017
+
+This is a public release of libpng, intended for use in production codes.
+
+Files available for download:
+
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
+
+   libpng-1.6.34.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.34.tar.gz
+
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+
+   lpng1634.7z  (LZMA-compressed, recommended)
+   lpng1634.zip
+
+Other information:
+
+   libpng-1.6.34-README.txt
+   libpng-1.6.34-LICENSE.txt
+   libpng-1.6.34-*.asc (armored detached GPG signatures)
+
+Changes since the last public release (1.6.33):
+  Removed contrib/pngsuite/i*.png; some of these were incorrect and caused
+    test failures.
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe)
+or to glennrp at users.sourceforge.net
+
+Glenn R-P
diff --git a/xs/src/png/libpng/CMakeLists.txt b/xs/src/png/libpng/CMakeLists.txt
new file mode 100644
index 000000000..266b67d0e
--- /dev/null
+++ b/xs/src/png/libpng/CMakeLists.txt
@@ -0,0 +1,937 @@
+# CMakeLists.txt
+
+# Copyright (C) 2007,2009-2017 Glenn Randers-Pehrson
+# Written by Christian Ehrlicher, 2007
+# Revised by Roger Lowman, 2009-2010
+# Revised by Clifford Yapp, 2011-2012
+# Revised by Roger Leigh, 2016
+# Revised by Andreas Franek, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+cmake_minimum_required(VERSION 3.0.2)
+cmake_policy(VERSION 3.0.2)
+
+# Set MacOSX @rpath usage globally.
+if (POLICY CMP0020)
+  cmake_policy(SET CMP0020 NEW)
+endif(POLICY CMP0020)
+if (POLICY CMP0042)
+  cmake_policy(SET CMP0042 NEW)
+endif(POLICY CMP0042)
+# Use new variable expansion policy.
+if (POLICY CMP0053)
+  cmake_policy(SET CMP0053 NEW)
+endif(POLICY CMP0053)
+if (POLICY CMP0054)
+  cmake_policy(SET CMP0054 NEW)
+endif(POLICY CMP0054)
+
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
+
+project(libpng ASM C)
+
+set(PNGLIB_MAJOR 1)
+set(PNGLIB_MINOR 6)
+set(PNGLIB_RELEASE 34)
+set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
+set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
+
+# needed packages
+
+#Allow users to specify location of Zlib,
+# Useful if zlib is being built alongside this as a sub-project
+
+set(PNG_BUILD_ZLIB ${CMAKE_CURRENT_SOURCE_DIR}/zlib)
+
+if(NOT WIN32)
+  find_library(M_LIBRARY
+    NAMES m
+    PATHS /usr/lib /usr/local/lib
+  )
+  if(NOT M_LIBRARY)
+    message(STATUS "math lib 'libm' not found; floating point support disabled")
+  endif()
+else()
+  # not needed on windows
+  set(M_LIBRARY "")
+endif()
+
+# COMMAND LINE OPTIONS
+option(PNG_SHARED "Build shared lib" OFF)
+option(PNG_STATIC "Build static lib" ON)
+option(PNG_TESTS  "Build libpng tests" OFF)
+
+# Many more configuration options could be added here
+option(PNG_FRAMEWORK "Build OS X framework" OFF)
+option(PNG_DEBUG     "Build with debug output" OFF)
+option(PNGARG        "Disable ANSI-C prototypes" OFF)
+
+option(PNG_HARDWARE_OPTIMIZATIONS "Enable Hardware Optimizations" ON)
+
+set(PNG_PREFIX "" CACHE STRING "Prefix to add to the API function names")
+set(DFA_XTRA "" CACHE FILEPATH "File containing extra configuration settings")
+
+if(PNG_HARDWARE_OPTIMIZATIONS)
+# set definitions and sources for arm
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
+  CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64")
+  set(PNG_ARM_NEON_POSSIBLE_VALUES check on off)
+  set(PNG_ARM_NEON "check" CACHE STRING "Enable ARM NEON optimizations:
+     check: (default) use internal checking code;
+     off: disable the optimizations;
+     on: turn on unconditionally.")
+  set_property(CACHE PNG_ARM_NEON PROPERTY STRINGS
+     ${PNG_ARM_NEON_POSSIBLE_VALUES})
+  list(FIND PNG_ARM_NEON_POSSIBLE_VALUES ${PNG_ARM_NEON} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_ARM_NEON must be one of [${PNG_ARM_NEON_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_ARM_NEON} STREQUAL "no")
+    set(libpng_arm_sources
+      arm/arm_init.c
+      arm/filter_neon.S
+      arm/filter_neon_intrinsics.c)
+
+    if(${PNG_ARM_NEON} STREQUAL "on")
+      add_definitions(-DPNG_ARM_NEON_OPT=2)
+    elseif(${PNG_ARM_NEON} STREQUAL "check")
+      add_definitions(-DPNG_ARM_NEON_CHECK_SUPPORTED)
+    endif()
+  else()
+    add_definitions(-DPNG_ARM_NEON_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for powerpc
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^powerpc*" OR
+	CMAKE_SYSTEM_PROCESSOR MATCHES "^ppc64*" )
+  set(PNG_POWERPC_VSX_POSSIBLE_VALUES on off)
+  set(PNG_POWERPC_VSX "on" CACHE STRING "Enable POWERPC VSX optimizations:
+     off: disable the optimizations.")
+  set_property(CACHE PNG_POWERPC_VSX PROPERTY STRINGS
+     ${PNG_POWERPC_VSX_POSSIBLE_VALUES})
+  list(FIND PNG_POWERPC_VSX_POSSIBLE_VALUES ${PNG_POWERPC_VSX} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_POWERPC_VSX must be one of [${PNG_POWERPC_VSX_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_POWERPC_VSX} STREQUAL "no")
+    set(libpng_powerpc_sources
+      powerpc/powerpc_init.c
+      powerpc/filter_vsx_intrinsics.c)
+    if(${PNG_POWERPC_VSX} STREQUAL "on")
+      add_definitions(-DPNG_POWERPC_VSX_OPT=2)
+    endif()
+  else()
+    add_definitions(-DPNG_POWERPC_VSX_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for intel
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^i?86" OR
+	CMAKE_SYSTEM_PROCESSOR MATCHES "^x86_64*" )
+  set(PNG_INTEL_SSE_POSSIBLE_VALUES on off)
+  set(PNG_INTEL_SSE "on" CACHE STRING "Enable INTEL_SSE optimizations:
+     off: disable the optimizations")
+  set_property(CACHE PNG_INTEL_SSE PROPERTY STRINGS
+     ${PNG_INTEL_SSE_POSSIBLE_VALUES})
+  list(FIND PNG_INTEL_SSE_POSSIBLE_VALUES ${PNG_INTEL_SSE} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_INTEL_SSE must be one of [${PNG_INTEL_SSE_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_INTEL_SSE} STREQUAL "no")
+    set(libpng_intel_sources
+      intel/intel_init.c
+      intel/filter_sse2_intrinsics.c)
+    if(${PNG_INTEL_SSE} STREQUAL "on")
+      add_definitions(-DPNG_INTEL_SSE_OPT=1)
+    endif()
+  else()
+    add_definitions(-DPNG_INTEL_SSE_OPT=0)
+  endif()
+endif()
+
+# set definitions and sources for MIPS
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "mipsel*" OR
+	CMAKE_SYSTEM_PROCESSOR MATCHES "mips64el*" )
+  set(PNG_MIPS_MSA_POSSIBLE_VALUES on off)
+  set(PNG_MIPS_MSA "on" CACHE STRING "Enable MIPS_MSA optimizations:
+     off: disable the optimizations")
+  set_property(CACHE PNG_MIPS_MSA PROPERTY STRINGS
+     ${PNG_MIPS_MSA_POSSIBLE_VALUES})
+  list(FIND PNG_MIPS_MSA_POSSIBLE_VALUES ${PNG_MIPS_MSA} index)
+  if(index EQUAL -1)
+    message(FATAL_ERROR
+      " PNG_MIPS_MSA must be one of [${PNG_MIPS_MSA_POSSIBLE_VALUES}]")
+  elseif(NOT ${PNG_MIPS_MSA} STREQUAL "no")
+    set(libpng_mips_sources
+      mips/mips_init.c
+      mips/filter_msa_intrinsics.c)
+    if(${PNG_MIPS_MSA} STREQUAL "on")
+      add_definitions(-DPNG_MIPS_MSA_OPT=2)
+    endif()
+  else()
+    add_definitions(-DPNG_MIPS_MSA_OPT=0)
+  endif()
+endif()
+endif(PNG_HARDWARE_OPTIMIZATIONS)
+
+# SET LIBNAME
+set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
+
+# to distinguish between debug and release lib
+set(CMAKE_DEBUG_POSTFIX "d")
+
+include(CheckCSourceCompiles)
+option(ld-version-script "Enable linker version script" ON)
+if(ld-version-script AND NOT APPLE)
+  # Check if LD supports linker scripts.
+  file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map" "VERS_1 {
+        global: sym;
+        local: *;
+};
+
+VERS_2 {
+        global: sym2;
+                main;
+} VERS_1;
+")
+  set(CMAKE_REQUIRED_FLAGS_SAVE ${CMAKE_REQUIRED_FLAGS})
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/conftest.map'")
+  check_c_source_compiles("void sym(void) {}
+void sym2(void) {}
+int main(void) {return 0;}
+" HAVE_LD_VERSION_SCRIPT)
+  if(NOT HAVE_LD_VERSION_SCRIPT)
+    set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE} "-Wl,-M -Wl,${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+  check_c_source_compiles("void sym(void) {}
+void sym2(void) {}
+int main(void) {return 0;}
+" HAVE_SOLARIS_LD_VERSION_SCRIPT)
+  endif()
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE})
+  file(REMOVE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+endif()
+
+# Find symbol prefix.  Likely obsolete and unnecessary with recent
+# toolchains (it's not done in many other projects).
+function(symbol_prefix)
+  set(SYMBOL_PREFIX)
+
+  execute_process(COMMAND "${CMAKE_C_COMPILER}" "-E" "-"
+                  INPUT_FILE /dev/null
+                  OUTPUT_VARIABLE OUT
+                  RESULT_VARIABLE STATUS)
+
+  if(CPP_FAIL)
+    message(WARNING "Failed to run the C preprocessor")
+  endif()
+
+  string(REPLACE "\n" ";" OUT "${OUT}")
+  foreach(line ${OUT})
+    string(REGEX MATCH "^PREFIX=" found_match "${line}")
+    if(found_match)
+      STRING(REGEX REPLACE "^PREFIX=(.*\)" "\\1" prefix "${line}")
+      string(REGEX MATCH "__USER_LABEL_PREFIX__" found_match "${prefix}")
+      if(found_match)
+        STRING(REGEX REPLACE "(.*)__USER_LABEL_PREFIX__(.*)" "\\1\\2" prefix "${prefix}")
+      endif()
+      set(SYMBOL_PREFIX "${prefix}")
+    endif()
+  endforeach()
+
+    message(STATUS "Symbol prefix: ${SYMBOL_PREFIX}")
+    set(SYMBOL_PREFIX "${SYMBOL_PREFIX}" PARENT_SCOPE)
+endfunction()
+
+if(UNIX)
+  symbol_prefix()
+endif()
+
+find_program(AWK NAMES gawk awk)
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+if(NOT AWK OR ANDROID)
+  # No awk available to generate sources; use pre-built pnglibconf.h
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
+                 ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
+  add_custom_target(genfiles) # Dummy
+else()
+  include(CMakeParseArguments)
+  # Generate .chk from .out with awk
+  # generate_chk(INPUT inputfile OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_chk)
+    set(options)
+    set(oneValueArgs INPUT OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GC "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GC_INPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    endif()
+    if (NOT _GC_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${_GC_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DINPUT=${_GC_INPUT}"
+                               "-DOUTPUT=${_GC_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/genchk.cmake"
+                       DEPENDS "${_GC_INPUT}" ${_GC_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Generate .out from .c with awk
+  # generate_out(INPUT inputfile OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_out)
+    set(options)
+    set(oneValueArgs INPUT OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GO_INPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    endif()
+    if (NOT _GO_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${_GO_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DINPUT=${_GO_INPUT}"
+                               "-DOUTPUT=${_GO_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/genout.cmake"
+                       DEPENDS "${_GO_INPUT}" ${_GO_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Generate specific source file with awk
+  # generate_source(OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_source)
+    set(options)
+    set(oneValueArgs OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GSO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GSO_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_source requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${_GSO_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DOUTPUT=${_GSO_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake"
+                       DEPENDS ${_GSO_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Copy file
+  function(generate_copy source destination)
+    add_custom_command(OUTPUT "${destination}"
+                       COMMAND "${CMAKE_COMMAND}" -E remove "${destination}"
+                       COMMAND "${CMAKE_COMMAND}" -E copy "${source}"
+                                                          "${destination}"
+                       DEPENDS "${source}")
+  endfunction()
+
+  # Generate scripts/pnglibconf.h
+  generate_source(OUTPUT "scripts/pnglibconf.c"
+                  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+
+  # Generate pnglibconf.c
+  generate_source(OUTPUT "pnglibconf.c"
+                  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+
+  if(PNG_PREFIX)
+    set(PNGLIBCONF_H_EXTRA_DEPENDS
+        "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+        "${CMAKE_CURRENT_SOURCE_DIR}/scripts/macro.lst")
+    set(PNGPREFIX_H_EXTRA_DEPENDS
+        "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out")
+  endif()
+
+  generate_out(INPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+  # Generate pnglibconf.h
+  generate_source(OUTPUT "pnglibconf.h"
+                  DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+                          ${PNGLIBCONF_H_EXTRA_DEPENDS})
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/intprefix.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+               DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/prefix.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+  # Generate pngprefix.h
+  generate_source(OUTPUT "pngprefix.h"
+                  DEPENDS ${PNGPREFIX_H_EXTRA_DEPENDS})
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/sym.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+               DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/vers.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_chk(INPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/checksym.awk"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.def")
+
+  add_custom_target(symbol-check DEPENDS
+                    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk")
+
+  generate_copy("${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+                "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+  generate_copy("${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+                "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+
+  add_custom_target(genvers DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+  add_custom_target(gensym DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+
+  add_custom_target("genprebuilt"
+                    COMMAND "${CMAKE_COMMAND}"
+                            "-DOUTPUT=scripts/pnglibconf.h.prebuilt"
+                            -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake"
+                    WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+
+  # A single target handles generation of all generated files.  If
+  # they are dependend upon separately by multiple targets, this
+  # confuses parallel make (it would require a separate top-level
+  # target for each file to track the dependencies properly).
+  add_custom_target(genfiles DEPENDS
+    "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym"
+    "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/pnglibconf.c"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out")
+endif(NOT AWK OR ANDROID)
+
+# OUR SOURCES
+set(libpng_public_hdrs
+  png.h
+  pngconf.h
+  "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+)
+set(libpng_private_hdrs
+  pngpriv.h
+  pngdebug.h
+  pnginfo.h
+  pngstruct.h
+)
+if(AWK AND NOT ANDROID)
+  list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
+endif()
+set(libpng_sources
+  ${libpng_public_hdrs}
+  ${libpng_private_hdrs}
+  png.c
+  pngerror.c
+  pngget.c
+  pngmem.c
+  pngpread.c
+  pngread.c
+  pngrio.c
+  pngrtran.c
+  pngrutil.c
+  pngset.c
+  pngtrans.c
+  pngwio.c
+  pngwrite.c
+  pngwtran.c
+  pngwutil.c
+  ${libpng_arm_sources}
+  ${libpng_intel_sources}
+  ${libpng_mips_sources}
+  ${libpng_powerpc_sources}
+)
+set(pngtest_sources
+  pngtest.c
+)
+set(pngvalid_sources
+  contrib/libtests/pngvalid.c
+)
+set(pngstest_sources
+  contrib/libtests/pngstest.c
+)
+set(pngunknown_sources
+  contrib/libtests/pngunknown.c
+)
+set(pngimage_sources
+  contrib/libtests/pngimage.c
+)
+set(pngfix_sources
+  contrib/tools/pngfix.c
+)
+set(png_fix_itxt_sources
+  contrib/tools/png-fix-itxt.c
+)
+
+if(MSVC)
+  add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif(MSVC)
+
+if(PNG_DEBUG)
+  add_definitions(-DPNG_DEBUG)
+endif()
+
+# NOW BUILD OUR TARGET
+include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
+
+unset(PNG_LIB_TARGETS)
+
+if(PNG_SHARED)
+  add_library(png SHARED ${libpng_sources})
+  set(PNG_LIB_TARGETS png)
+  set_target_properties(png PROPERTIES OUTPUT_NAME ${PNG_LIB_NAME})
+  add_dependencies(png genfiles)
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(png PROPERTIES PREFIX "lib")
+    set_target_properties(png PROPERTIES IMPORT_PREFIX "lib")
+  endif()
+  target_link_libraries(png ${ZLIB_LIBRARY} ${M_LIBRARY})
+
+  if(UNIX AND AWK)
+    if(HAVE_LD_VERSION_SCRIPT)
+      set_target_properties(png PROPERTIES LINK_FLAGS
+        "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+    elseif(HAVE_SOLARIS_LD_VERSION_SCRIPT)
+      set_target_properties(png PROPERTIES LINK_FLAGS
+        "-Wl,-M -Wl,'${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+    endif()
+  endif()
+endif()
+
+if(PNG_STATIC)
+  # does not work without changing name
+  set(PNG_LIB_NAME_STATIC png_static)
+  add_library(png_static STATIC ${libpng_sources})
+  add_dependencies(png_static genfiles)
+  # MSVC doesn't use a different file extension for shared vs. static
+  # libs.  We are able to change OUTPUT_NAME to remove the _static
+  # for all other platforms.
+  if(NOT MSVC)
+    set_target_properties(png_static PROPERTIES
+      OUTPUT_NAME "${PNG_LIB_NAME}"
+      CLEAN_DIRECT_OUTPUT 1)
+  else()
+    set_target_properties(png_static PROPERTIES
+      OUTPUT_NAME "${PNG_LIB_NAME}_static"
+      CLEAN_DIRECT_OUTPUT 1)
+  endif()
+  list(APPEND PNG_LIB_TARGETS png_static)
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(png_static PROPERTIES PREFIX "lib")
+  endif()
+  target_link_libraries(png_static ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(PNG_FRAMEWORK)
+  set(PNG_LIB_NAME_FRAMEWORK png_framework)
+  add_library(png_framework SHARED ${libpng_sources})
+  add_dependencies(png_framework genfiles)
+  list(APPEND PNG_LIB_TARGETS png_framework)
+  set_target_properties(png_framework PROPERTIES
+    FRAMEWORK TRUE
+    FRAMEWORK_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_SHORT_VERSION_STRING ${PNGLIB_MAJOR}.${PNGLIB_MINOR}
+    MACOSX_FRAMEWORK_BUNDLE_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_IDENTIFIER org.libpng.libpng
+    XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+    PUBLIC_HEADER "${libpng_public_hdrs}"
+    OUTPUT_NAME png)
+  target_link_libraries(png_framework ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(NOT PNG_LIB_TARGETS)
+  message(SEND_ERROR
+    "No library variant selected to build. "
+    "Please enable at least one of the following options: "
+    " PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
+endif()
+
+if(PNG_SHARED AND WIN32)
+  set_target_properties(png PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
+endif()
+
+function(png_add_test)
+  set(options)
+  set(oneValueArgs NAME COMMAND)
+  set(multiValueArgs OPTIONS FILES)
+  cmake_parse_arguments(_PAT "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+  if (NOT _PAT_NAME)
+    message(FATAL_ERROR "Invalid arguments.  png_add_test requires name.")
+  endif()
+  if (NOT _PAT_COMMAND)
+    message(FATAL_ERROR "Invalid arguments.  png_add_test requires command.")
+  endif()
+
+  set(TEST_OPTIONS "${_PAT_OPTIONS}")
+  set(TEST_FILES "${_PAT_FILES}")
+
+  configure_file("${CMAKE_CURRENT_SOURCE_DIR}/scripts/test.cmake.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake" @ONLY)
+  if(CMAKE_MAJOR_VERSION GREATER 2) # have generator expressions
+    add_test(NAME "${_PAT_NAME}"
+             COMMAND "${CMAKE_COMMAND}"
+             "-DLIBPNG=$<TARGET_FILE:png>"
+             "-DTEST_COMMAND=$<TARGET_FILE:${_PAT_COMMAND}>"
+             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
+  else() # old 2.x add_test; limited and won't work well on Windows
+    # Note LIBPNG is a dummy value as there are no generator expressions
+    add_test("${_PAT_NAME}" "${CMAKE_COMMAND}"
+             "-DLIBPNG=${CMAKE_CURRENT_BINARY_DIR}/libpng.so"
+             "-DTEST_COMMAND=./${_PAT_COMMAND}"
+             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
+  endif()
+endfunction()
+
+if(PNG_TESTS AND PNG_SHARED)
+  # Find test PNG files by globbing, but sort lists to ensure
+  # consistency between different filesystems.
+  file(GLOB PNGSUITE_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/*.png")
+  list(SORT PNGSUITE_PNGS)
+  file(GLOB TEST_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/testpngs/*.png")
+  list(SORT TEST_PNGS)
+
+  set(PNGTEST_PNG "${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png")
+
+  add_executable(pngtest ${pngtest_sources})
+  target_link_libraries(pngtest png)
+
+  png_add_test(NAME pngtest COMMAND pngtest FILES "${PNGTEST_PNG}")
+
+  add_executable(pngvalid ${pngvalid_sources})
+  target_link_libraries(pngvalid png)
+
+  png_add_test(NAME pngvalid-gamma-16-to-8
+               COMMAND pngvalid OPTIONS --gamma-16-to-8)
+  png_add_test(NAME pngvalid-gamma-alpha-mode
+               COMMAND pngvalid OPTIONS --gamma-alpha-mode)
+  png_add_test(NAME pngvalid-gamma-background
+               COMMAND pngvalid OPTIONS --gamma-background)
+  png_add_test(NAME pngvalid-gamma-expand16-alpha-mode
+               COMMAND pngvalid OPTIONS --gamma-alpha-mode --expand16)
+  png_add_test(NAME pngvalid-gamma-expand16-background
+               COMMAND pngvalid OPTIONS --gamma-background --expand16)
+  png_add_test(NAME pngvalid-gamma-expand16-transform
+               COMMAND pngvalid OPTIONS --gamma-transform --expand16)
+  png_add_test(NAME pngvalid-gamma-sbit
+               COMMAND pngvalid OPTIONS --gamma-sbit)
+  png_add_test(NAME pngvalid-gamma-threshold
+               COMMAND pngvalid OPTIONS --gamma-threshold)
+  png_add_test(NAME pngvalid-gamma-transform
+               COMMAND pngvalid OPTIONS --gamma-transform)
+  png_add_test(NAME pngvalid-progressive-interlace-standard
+               COMMAND pngvalid OPTIONS --standard --progressive-read --interlace)
+  png_add_test(NAME pngvalid-progressive-size
+               COMMAND pngvalid OPTIONS --size --progressive-read)
+  png_add_test(NAME pngvalid-progressive-standard
+               COMMAND pngvalid OPTIONS --standard --progressive-read)
+  png_add_test(NAME pngvalid-standard
+               COMMAND pngvalid OPTIONS --standard)
+  png_add_test(NAME pngvalid-transform
+               COMMAND pngvalid OPTIONS --transform)
+
+  add_executable(pngstest ${pngstest_sources})
+  target_link_libraries(pngstest png)
+
+  foreach(gamma_type 1.8 linear none sRGB)
+    foreach(alpha_type none alpha)
+      set(PNGSTEST_FILES)
+      foreach(test_png ${TEST_PNGS})
+        string(REGEX MATCH ".*-linear[-.].*" TEST_PNG_LINEAR "${test_png}")
+        string(REGEX MATCH ".*-sRGB[-.].*" TEST_PNG_SRGB "${test_png}")
+        string(REGEX MATCH ".*-1.8[-.].*" TEST_PNG_G18 "${test_png}")
+        string(REGEX MATCH ".*-alpha-.*" TEST_PNG_ALPHA "${test_png}")
+
+        set(TEST_PNG_VALID TRUE)
+
+        if(TEST_PNG_ALPHA)
+          if (NOT "${alpha_type}" STREQUAL "alpha")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        else()
+          if ("${alpha_type}" STREQUAL "alpha")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        endif()
+
+        if(TEST_PNG_LINEAR)
+          if(NOT "${gamma_type}" STREQUAL "linear")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        elseif(TEST_PNG_SRGB)
+          if(NOT "${gamma_type}" STREQUAL "sRGB")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        elseif(TEST_PNG_G18)
+          if(NOT "${gamma_type}" STREQUAL "1.8")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        else()
+          if(NOT "${gamma_type}" STREQUAL "none")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        endif()
+
+        if(TEST_PNG_VALID)
+          list(APPEND PNGSTEST_FILES "${test_png}")
+        endif()
+      endforeach()
+      # Should already be sorted, but sort anyway to be certain.
+      list(SORT PNGSTEST_FILES)
+      png_add_test(NAME pngstest-${gamma_type}-${alpha_type}
+                   COMMAND pngstest
+                   OPTIONS --tmpfile "${gamma_type}-${alpha_type}-" --log
+                   FILES ${PNGSTEST_FILES})
+    endforeach()
+  endforeach()
+
+  add_executable(pngunknown ${pngunknown_sources})
+  target_link_libraries(pngunknown png)
+
+  png_add_test(NAME pngunknown-discard COMMAND pngunknown OPTIONS --strict default=discard FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-IDAT COMMAND pngunknown OPTIONS --strict default=discard IDAT=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-if-safe COMMAND pngunknown OPTIONS --strict default=if-safe FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-sAPI COMMAND pngunknown OPTIONS --strict bKGD=save cHRM=save gAMA=save all=discard iCCP=save sBIT=save sRGB=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-save COMMAND pngunknown OPTIONS --strict default=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-sTER COMMAND pngunknown OPTIONS --strict sTER=if-safe FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-vpAg COMMAND pngunknown OPTIONS --strict vpAg=if-safe FILES "${PNGTEST_PNG}")
+
+  add_executable(pngimage ${pngimage_sources})
+  target_link_libraries(pngimage png)
+
+  png_add_test(NAME pngimage-quick COMMAND pngimage OPTIONS --list-combos --log FILES ${PNGSUITE_PNGS})
+  png_add_test(NAME pngimage-full COMMAND pngimage OPTIONS --exhaustive --list-combos --log FILES ${PNGSUITE_PNGS})
+endif()
+
+if(PNG_SHARED)
+  add_executable(pngfix ${pngfix_sources})
+  target_link_libraries(pngfix png)
+  set(PNG_BIN_TARGETS pngfix)
+
+  add_executable(png-fix-itxt ${png_fix_itxt_sources})
+  target_link_libraries(png-fix-itxt ${ZLIB_LIBRARY} ${M_LIBRARY})
+  list(APPEND PNG_BIN_TARGETS png-fix-itxt)
+endif()
+
+# Set a variable with CMake code which:
+# Creates a symlink from src to dest (if possible) or alternatively
+# copies if different.
+include(CMakeParseArguments)
+
+function(CREATE_SYMLINK DEST_FILE)
+
+  cmake_parse_arguments(S "" "FILE;TARGET" "" ${ARGN})
+
+  if(NOT S_TARGET AND NOT S_FILE)
+    message(FATAL_ERROR "Specify either a TARGET or a FILE for CREATE_SYMLINK to link to.")
+  endif(NOT S_TARGET AND NOT S_FILE)
+
+  if(S_TARGET AND S_FILE)
+    message(FATAL_ERROR "CREATE_SYMLINK called with both source file ${S_FILE} and build target ${S_TARGET} arguments - can only handle 1 type per call.")
+  endif(S_TARGET AND S_FILE)
+
+  if(S_FILE)
+    # If we don't need to symlink something that's coming from a build target,
+    # we can go ahead and symlink/copy at configure time.
+
+    if(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      execute_process(
+	COMMAND "${CMAKE_COMMAND}" -E copy_if_different ${S_FILE} ${DEST_FILE}
+	WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+	)
+    else(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      execute_process(
+	COMMAND ${CMAKE_COMMAND} -E create_symlink ${S_FILE} ${DEST_FILE}
+	WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
+	)
+    endif(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+  endif(S_FILE)
+
+  if(S_TARGET)
+    # We need to use generator expressions, which can be a bit tricky, so for
+    # simplicity make the symlink a POST_BUILD step and use the TARGET
+    # signature of add_custom_command.
+
+    if(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      add_custom_command(TARGET ${S_TARGET} POST_BUILD
+	COMMAND "${CMAKE_COMMAND}" -E copy_if_different $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE}
+	)
+    else(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+      add_custom_command(TARGET ${S_TARGET} POST_BUILD
+	COMMAND "${CMAKE_COMMAND}" -E create_symlink $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE}
+	)
+    endif(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
+
+  endif(S_TARGET)
+
+endfunction()
+
+# Create source generation scripts.
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genchk.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/genchk.cmake @ONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genout.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/genout.cmake @ONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/gensrc.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake @ONLY)
+
+
+# libpng is a library so default to 'lib'
+if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+  set(CMAKE_INSTALL_LIBDIR lib)
+endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+
+# CREATE PKGCONFIG FILES
+# we use the same files like ./configure, so we have to set its vars
+# Only do this on Windows for Cygwin - the files don't make much sense outside
+# a UNIX look alike
+if(NOT WIN32 OR CYGWIN OR MINGW)
+  set(prefix      ${CMAKE_INSTALL_PREFIX})
+  set(exec_prefix ${CMAKE_INSTALL_PREFIX})
+  set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
+  set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
+  set(LIBS        "-lz -lm")
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
+  CREATE_SYMLINK(libpng.pc FILE ${PNGLIB_NAME}.pc)
+
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
+  CREATE_SYMLINK(libpng-config FILE ${PNGLIB_NAME}-config)
+endif(NOT WIN32 OR CYGWIN OR MINGW)
+
+# SET UP LINKS
+if(PNG_SHARED)
+  set_target_properties(png PROPERTIES
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.34
+    VERSION 16.${PNGLIB_RELEASE}.0
+    SOVERSION 16
+    CLEAN_DIRECT_OUTPUT 1)
+endif()
+
+# If CMake > 2.4.x, we set a variable used below to export
+# targets to an export file.
+# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2
+if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4)
+  set(PNG_EXPORT_RULE EXPORT libpng)
+elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof
+  set(PNG_EXPORT_RULE EXPORT libpng)
+endif()
+
+# INSTALL
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+  install(TARGETS ${PNG_LIB_TARGETS}
+      ${PNG_EXPORT_RULE}
+      RUNTIME DESTINATION bin
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+  if(PNG_SHARED)
+    # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
+    if(CYGWIN OR MINGW)
+      CREATE_SYMLINK(libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} TARGET png)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(CYGWIN OR MINGW)
+
+    if(NOT WIN32)
+      CREATE_SYMLINK(libpng${CMAKE_SHARED_LIBRARY_SUFFIX} TARGET png)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_SHARED_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32)
+  endif(PNG_SHARED)
+
+  if(PNG_STATIC)
+    if(NOT WIN32 OR CYGWIN OR MINGW)
+      CREATE_SYMLINK( libpng${CMAKE_STATIC_LIBRARY_SUFFIX} TARGET png_static)
+      install(FILES $<TARGET_LINKER_FILE_DIR:png_static>/libpng${CMAKE_STATIC_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32 OR CYGWIN OR MINGW)
+ endif()
+endif()
+
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
+  install(FILES ${libpng_public_hdrs}   DESTINATION include)
+  install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
+endif()
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
+endif()
+
+if(NOT SKIP_INSTALL_PROGRAMS AND NOT SKIP_INSTALL_ALL )
+  install(TARGETS ${PNG_BIN_TARGETS}
+      RUNTIME DESTINATION bin)
+endif()
+
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+  # Install man pages
+  if(NOT PNG_MAN_DIR)
+    set(PNG_MAN_DIR "share/man")
+  endif()
+  install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
+  install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
+  # Install pkg-config files
+  if(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
+            DESTINATION bin)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+endif()
+
+# On versions of CMake that support it, create an export file CMake
+# users can include() to import our targets
+if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL )
+  install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake)
+endif()
+
+# what's with libpng-manual.txt and all the extra files?
+
+# UNINSTALL
+# do we need this?
+
+# DIST
+# do we need this?
+
+# to create msvc import lib for mingw compiled shared lib
+# pexports libpng.dll > libpng.def
+# lib /def:libpng.def /machine:x86
diff --git a/xs/src/png/libpng/LICENSE b/xs/src/png/libpng/LICENSE
new file mode 100644
index 000000000..4cda4fa0a
--- /dev/null
+++ b/xs/src/png/libpng/LICENSE
@@ -0,0 +1,133 @@
+
+This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+This code is released under the libpng license.
+
+libpng versions 1.0.7, July 1, 2000 through 1.6.34, September 29, 2017 are
+Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
+derived from libpng-1.0.6, and are distributed according to the same
+disclaimer and license as libpng-1.0.6 with the following individuals
+added to the list of Contributing Authors:
+
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Mans Rullgard
+   Cosmin Truta
+   Gilles Vollant
+   James Yu
+   Mandar Sahastrabuddhe
+   Google Inc.
+   Vadim Barkov
+
+and with the following additions to the disclaimer:
+
+   There is no warranty against interference with your enjoyment of the
+   library or against infringement.  There is no warranty that our
+   efforts or the library will fulfill any of your particular purposes
+   or needs.  This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and effort is with
+   the user.
+
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners and
+are released under other open source licenses.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+libpng-0.96, and are distributed according to the same disclaimer and
+license as libpng-0.96, with the following individuals added to the list
+of Contributing Authors:
+
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+and are distributed according to the same disclaimer and license as
+libpng-0.88, with the following individuals added to the list of
+Contributing Authors:
+
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+
+Some files in the "scripts" directory have other copyright owners
+but are released under this license.
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+  1. The origin of this source code must not be misrepresented.
+
+  2. Altered versions must be plainly marked as such and must not
+     be misrepresented as being the original source.
+
+  3. This Copyright notice may not be removed or altered from any
+     source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
+
+TRADEMARK:
+
+The name "libpng" has not been registered by the Copyright owner
+as a trademark in any jurisdiction.  However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owner claims "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.
+
+OSI CERTIFICATION:
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+a certification mark of the Open Source Initiative. OSI has not addressed
+the additional disclaimers inserted at version 1.0.7.
+
+EXPORT CONTROL:
+
+The Copyright owner believes that the Export Control Classification
+Number (ECCN) for libpng is EAR99, which means not subject to export
+controls or International Traffic in Arms Regulations (ITAR) because
+it is open source, publicly available software, that does not contain
+any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
+734.7(b).
+
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+September 29, 2017
diff --git a/xs/src/png/libpng/libpng-config.in b/xs/src/png/libpng/libpng-config.in
new file mode 100644
index 000000000..69bf8e33f
--- /dev/null
+++ b/xs/src/png/libpng/libpng-config.in
@@ -0,0 +1,127 @@
+#! /bin/sh
+
+# libpng-config
+# provides configuration info for libpng.
+
+# Copyright (C) 2002, 2004, 2006, 2007 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Modeled after libxml-config.
+
+version="@PNGLIB_VERSION@"
+prefix="@prefix@"
+exec_prefix="@exec_prefix@"
+libdir="@libdir@"
+includedir="@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@"
+all_libs="-lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ @LIBS@"
+I_opts="-I${includedir}"
+L_opts="-L${libdir}"
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
+
+usage()
+{
+    cat <<EOF
+Usage: $0 [OPTION] ...
+
+Known values for OPTION are:
+
+  --prefix        print libpng prefix
+  --libdir        print path to directory containing library
+  --libs          print library linking information
+  --ccopts        print compiler options
+  --cppflags      print pre-processor flags
+  --cflags        print preprocessor flags, I_opts, and compiler options
+  --I_opts        print "-I" include options
+  --L_opts        print linker "-L" flags for dynamic linking
+  --R_opts        print dynamic linker "-R" or "-rpath" flags
+  --ldopts        print linker options
+  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)
+  --static        revise subsequent outputs for static linking
+  --help          print this help and exit
+  --version       print version information
+EOF
+
+    exit $1
+}
+
+if test $# -eq 0; then
+    usage 1
+fi
+
+while test $# -gt 0; do
+    case "$1" in
+
+    --prefix)
+        echo ${prefix}
+        ;;
+
+    --version)
+        echo ${version}
+        exit 0
+        ;;
+
+    --help)
+        usage 0
+        ;;
+
+    --ccopts)
+        echo ${ccopts}
+        ;;
+
+    --cppflags)
+        echo ${cppflags}
+        ;;
+
+    --cflags)
+        echo ${I_opts} ${cppflags} ${ccopts}
+        ;;
+
+    --libdir)
+        echo ${libdir}
+        ;;
+
+    --libs)
+        echo ${libs}
+        ;;
+
+    --I_opts)
+        echo ${I_opts}
+        ;;
+
+    --L_opts)
+        echo ${L_opts}
+        ;;
+
+    --R_opts)
+        echo ${R_opts}
+        ;;
+
+    --ldopts)
+        echo ${ldopts}
+        ;;
+
+    --ldflags)
+        echo ${ldopts} ${L_opts} ${R_opts} ${libs}
+        ;;
+
+    --static)
+        R_opts=""
+        libs=${all_libs}
+        ;;
+
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+    shift
+done
+
+exit 0
diff --git a/xs/src/png/libpng/libpng.pc.in b/xs/src/png/libpng/libpng.pc.in
new file mode 100644
index 000000000..9708e9af2
--- /dev/null
+++ b/xs/src/png/libpng/libpng.pc.in
@@ -0,0 +1,12 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+
+Name: libpng
+Description: Loads and saves PNG files
+Version: @PNGLIB_VERSION@
+Requires: zlib
+Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+Libs.private: @LIBS@
+Cflags: -I${includedir}
diff --git a/xs/src/png/libpng/png.c b/xs/src/png/libpng/png.c
new file mode 100644
index 000000000..ff02c5651
--- /dev/null
+++ b/xs/src/png/libpng/png.c
@@ -0,0 +1,4614 @@
+
+/* png.c - location for general purpose libpng functions
+ *
+ * Last changed in libpng 1.6.33 [September 28, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef png_libpng_version_1_6_34 Your_png_h_is_not_version_1_6_34;
+
+#ifdef __GNUC__
+/* The version tests may need to be added to, but the problem warning has
+ * consistently been fixed in GCC versions which obtain wide-spread release.
+ * The problem is that many versions of GCC rearrange comparison expressions in
+ * the optimizer in such a way that the results of the comparison will change
+ * if signed integer overflow occurs.  Such comparisons are not permitted in
+ * ANSI C90, however GCC isn't clever enough to work out that that do not occur
+ * below in png_ascii_from_fp and png_muldiv, so it produces a warning with
+ * -Wextra.  Unfortunately this is highly dependent on the optimizer and the
+ * machine architecture so the warning comes and goes unpredictably and is
+ * impossible to "fix", even were that a good idea.
+ */
+#if __GNUC__ == 7 && __GNUC_MINOR__ == 1
+#define GCC_STRICT_OVERFLOW 1
+#endif /* GNU 7.1.x */
+#endif /* GNU */
+#ifndef GCC_STRICT_OVERFLOW
+#define GCC_STRICT_OVERFLOW 0
+#endif
+
+/* Tells libpng that we have already handled the first "num_bytes" bytes
+ * of the PNG file signature.  If the PNG data is embedded into another
+ * stream we can set num_bytes = 8 so that libpng will not attempt to read
+ * or write any of the magic bytes before it starts on the IHDR.
+ */
+
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_set_sig_bytes(png_structrp png_ptr, int num_bytes)
+{
+   unsigned int nb = (unsigned int)num_bytes;
+
+   png_debug(1, "in png_set_sig_bytes");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (num_bytes < 0)
+      nb = 0;
+
+   if (nb > 8)
+      png_error(png_ptr, "Too many bytes for PNG signature");
+
+   png_ptr->sig_bytes = (png_byte)nb;
+}
+
+/* Checks whether the supplied bytes match the PNG signature.  We allow
+ * checking less than the full 8-byte signature so that those apps that
+ * already read the first few bytes of a file to determine the file type
+ * can simply check the remaining bytes for extra assurance.  Returns
+ * an integer less than, equal to, or greater than zero if sig is found,
+ * respectively, to be less than, to match, or be greater than the correct
+ * PNG signature (this is the same behavior as strcmp, memcmp, etc).
+ */
+int PNGAPI
+png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check)
+{
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+   if (num_to_check > 8)
+      num_to_check = 8;
+
+   else if (num_to_check < 1)
+      return (-1);
+
+   if (start > 7)
+      return (-1);
+
+   if (start + num_to_check > 8)
+      num_to_check = 8 - start;
+
+   return ((int)(memcmp(&sig[start], &png_signature[start], num_to_check)));
+}
+
+#endif /* READ */
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Function to allocate memory for zlib */
+PNG_FUNCTION(voidpf /* PRIVATE */,
+png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED)
+{
+   png_alloc_size_t num_bytes = size;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   if (items >= (~(png_alloc_size_t)0)/size)
+   {
+      png_warning (png_voidcast(png_structrp, png_ptr),
+          "Potential overflow in png_zalloc()");
+      return NULL;
+   }
+
+   num_bytes *= items;
+   return png_malloc_warn(png_voidcast(png_structrp, png_ptr), num_bytes);
+}
+
+/* Function to free memory for zlib */
+void /* PRIVATE */
+png_zfree(voidpf png_ptr, voidpf ptr)
+{
+   png_free(png_voidcast(png_const_structrp,png_ptr), ptr);
+}
+
+/* Reset the CRC variable to 32 bits of 1's.  Care must be taken
+ * in case CRC is > 32 bits to leave the top bits 0.
+ */
+void /* PRIVATE */
+png_reset_crc(png_structrp png_ptr)
+{
+   /* The cast is safe because the crc is a 32-bit value. */
+   png_ptr->crc = (png_uint_32)crc32(0, Z_NULL, 0);
+}
+
+/* Calculate the CRC over a section of data.  We can only pass as
+ * much data to this routine as the largest single buffer size.  We
+ * also check that this data will actually be used before going to the
+ * trouble of calculating it.
+ */
+void /* PRIVATE */
+png_calculate_crc(png_structrp png_ptr, png_const_bytep ptr, png_size_t length)
+{
+   int need_crc = 1;
+
+   if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
+   {
+      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+         need_crc = 0;
+   }
+
+   else /* critical */
+   {
+      if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+         need_crc = 0;
+   }
+
+   /* 'uLong' is defined in zlib.h as unsigned long; this means that on some
+    * systems it is a 64-bit value.  crc32, however, returns 32 bits so the
+    * following cast is safe.  'uInt' may be no more than 16 bits, so it is
+    * necessary to perform a loop here.
+    */
+   if (need_crc != 0 && length > 0)
+   {
+      uLong crc = png_ptr->crc; /* Should never issue a warning */
+
+      do
+      {
+         uInt safe_length = (uInt)length;
+#ifndef __COVERITY__
+         if (safe_length == 0)
+            safe_length = (uInt)-1; /* evil, but safe */
+#endif
+
+         crc = crc32(crc, ptr, safe_length);
+
+         /* The following should never issue compiler warnings; if they do the
+          * target system has characteristics that will probably violate other
+          * assumptions within the libpng code.
+          */
+         ptr += safe_length;
+         length -= safe_length;
+      }
+      while (length > 0);
+
+      /* And the following is always safe because the crc is only 32 bits. */
+      png_ptr->crc = (png_uint_32)crc;
+   }
+}
+
+/* Check a user supplied version number, called from both read and write
+ * functions that create a png_struct.
+ */
+int
+png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
+{
+   /* Libpng versions 1.0.0 and later are binary compatible if the version
+    * string matches through the second '.'; we must recompile any
+    * applications that use any older library version.
+    */
+
+   if (user_png_ver != NULL)
+   {
+      int i = -1;
+      int found_dots = 0;
+
+      do
+      {
+         i++;
+         if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i])
+            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+         if (user_png_ver[i] == '.')
+            found_dots++;
+      } while (found_dots < 2 && user_png_ver[i] != 0 &&
+            PNG_LIBPNG_VER_STRING[i] != 0);
+   }
+
+   else
+      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+
+   if ((png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) != 0)
+   {
+#ifdef PNG_WARNINGS_SUPPORTED
+      size_t pos = 0;
+      char m[128];
+
+      pos = png_safecat(m, (sizeof m), pos,
+          "Application built with libpng-");
+      pos = png_safecat(m, (sizeof m), pos, user_png_ver);
+      pos = png_safecat(m, (sizeof m), pos, " but running with ");
+      pos = png_safecat(m, (sizeof m), pos, PNG_LIBPNG_VER_STRING);
+      PNG_UNUSED(pos)
+
+      png_warning(png_ptr, m);
+#endif
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+      png_ptr->flags = 0;
+#endif
+
+      return 0;
+   }
+
+   /* Success return. */
+   return 1;
+}
+
+/* Generic function to create a png_struct for either read or write - this
+ * contains the common initialization.
+ */
+PNG_FUNCTION(png_structp /* PRIVATE */,
+png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+   png_struct create_struct;
+#  ifdef PNG_SETJMP_SUPPORTED
+      jmp_buf create_jmp_buf;
+#  endif
+
+   /* This temporary stack-allocated structure is used to provide a place to
+    * build enough context to allow the user provided memory allocator (if any)
+    * to be called.
+    */
+   memset(&create_struct, 0, (sizeof create_struct));
+
+   /* Added at libpng-1.2.6 */
+#  ifdef PNG_USER_LIMITS_SUPPORTED
+      create_struct.user_width_max = PNG_USER_WIDTH_MAX;
+      create_struct.user_height_max = PNG_USER_HEIGHT_MAX;
+
+#     ifdef PNG_USER_CHUNK_CACHE_MAX
+      /* Added at libpng-1.2.43 and 1.4.0 */
+      create_struct.user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
+#     endif
+
+#     ifdef PNG_USER_CHUNK_MALLOC_MAX
+      /* Added at libpng-1.2.43 and 1.4.1, required only for read but exists
+       * in png_struct regardless.
+       */
+      create_struct.user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX;
+#     endif
+#  endif
+
+   /* The following two API calls simply set fields in png_struct, so it is safe
+    * to do them now even though error handling is not yet set up.
+    */
+#  ifdef PNG_USER_MEM_SUPPORTED
+      png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn);
+#  else
+      PNG_UNUSED(mem_ptr)
+      PNG_UNUSED(malloc_fn)
+      PNG_UNUSED(free_fn)
+#  endif
+
+   /* (*error_fn) can return control to the caller after the error_ptr is set,
+    * this will result in a memory leak unless the error_fn does something
+    * extremely sophisticated.  The design lacks merit but is implicit in the
+    * API.
+    */
+   png_set_error_fn(&create_struct, error_ptr, error_fn, warn_fn);
+
+#  ifdef PNG_SETJMP_SUPPORTED
+      if (!setjmp(create_jmp_buf))
+#  endif
+      {
+#  ifdef PNG_SETJMP_SUPPORTED
+         /* Temporarily fake out the longjmp information until we have
+          * successfully completed this function.  This only works if we have
+          * setjmp() support compiled in, but it is safe - this stuff should
+          * never happen.
+          */
+         create_struct.jmp_buf_ptr = &create_jmp_buf;
+         create_struct.jmp_buf_size = 0; /*stack allocation*/
+         create_struct.longjmp_fn = longjmp;
+#  endif
+         /* Call the general version checker (shared with read and write code):
+          */
+         if (png_user_version_check(&create_struct, user_png_ver) != 0)
+         {
+            png_structrp png_ptr = png_voidcast(png_structrp,
+                png_malloc_warn(&create_struct, (sizeof *png_ptr)));
+
+            if (png_ptr != NULL)
+            {
+               /* png_ptr->zstream holds a back-pointer to the png_struct, so
+                * this can only be done now:
+                */
+               create_struct.zstream.zalloc = png_zalloc;
+               create_struct.zstream.zfree = png_zfree;
+               create_struct.zstream.opaque = png_ptr;
+
+#              ifdef PNG_SETJMP_SUPPORTED
+               /* Eliminate the local error handling: */
+               create_struct.jmp_buf_ptr = NULL;
+               create_struct.jmp_buf_size = 0;
+               create_struct.longjmp_fn = 0;
+#              endif
+
+               *png_ptr = create_struct;
+
+               /* This is the successful return point */
+               return png_ptr;
+            }
+         }
+      }
+
+   /* A longjmp because of a bug in the application storage allocator or a
+    * simple failure to allocate the png_struct.
+    */
+   return NULL;
+}
+
+/* Allocate the memory for an info_struct for the application. */
+PNG_FUNCTION(png_infop,PNGAPI
+png_create_info_struct,(png_const_structrp png_ptr),PNG_ALLOCATED)
+{
+   png_inforp info_ptr;
+
+   png_debug(1, "in png_create_info_struct");
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   /* Use the internal API that does not (or at least should not) error out, so
+    * that this call always returns ok.  The application typically sets up the
+    * error handling *after* creating the info_struct because this is the way it
+    * has always been done in 'example.c'.
+    */
+   info_ptr = png_voidcast(png_inforp, png_malloc_base(png_ptr,
+       (sizeof *info_ptr)));
+
+   if (info_ptr != NULL)
+      memset(info_ptr, 0, (sizeof *info_ptr));
+
+   return info_ptr;
+}
+
+/* This function frees the memory associated with a single info struct.
+ * Normally, one would use either png_destroy_read_struct() or
+ * png_destroy_write_struct() to free an info struct, but this may be
+ * useful for some applications.  From libpng 1.6.0 this function is also used
+ * internally to implement the png_info release part of the 'struct' destroy
+ * APIs.  This ensures that all possible approaches free the same data (all of
+ * it).
+ */
+void PNGAPI
+png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr)
+{
+   png_inforp info_ptr = NULL;
+
+   png_debug(1, "in png_destroy_info_struct");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (info_ptr_ptr != NULL)
+      info_ptr = *info_ptr_ptr;
+
+   if (info_ptr != NULL)
+   {
+      /* Do this first in case of an error below; if the app implements its own
+       * memory management this can lead to png_free calling png_error, which
+       * will abort this routine and return control to the app error handler.
+       * An infinite loop may result if it then tries to free the same info
+       * ptr.
+       */
+      *info_ptr_ptr = NULL;
+
+      png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+      memset(info_ptr, 0, (sizeof *info_ptr));
+      png_free(png_ptr, info_ptr);
+   }
+}
+
+/* Initialize the info structure.  This is now an internal function (0.89)
+ * and applications using it are urged to use png_create_info_struct()
+ * instead.  Use deprecated in 1.6.0, internal use removed (used internally it
+ * is just a memset).
+ *
+ * NOTE: it is almost inconceivable that this API is used because it bypasses
+ * the user-memory mechanism and the user error handling/warning mechanisms in
+ * those cases where it does anything other than a memset.
+ */
+PNG_FUNCTION(void,PNGAPI
+png_info_init_3,(png_infopp ptr_ptr, png_size_t png_info_struct_size),
+    PNG_DEPRECATED)
+{
+   png_inforp info_ptr = *ptr_ptr;
+
+   png_debug(1, "in png_info_init_3");
+
+   if (info_ptr == NULL)
+      return;
+
+   if ((sizeof (png_info)) > png_info_struct_size)
+   {
+      *ptr_ptr = NULL;
+      /* The following line is why this API should not be used: */
+      free(info_ptr);
+      info_ptr = png_voidcast(png_inforp, png_malloc_base(NULL,
+          (sizeof *info_ptr)));
+      if (info_ptr == NULL)
+         return;
+      *ptr_ptr = info_ptr;
+   }
+
+   /* Set everything to 0 */
+   memset(info_ptr, 0, (sizeof *info_ptr));
+}
+
+/* The following API is not called internally */
+void PNGAPI
+png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr,
+    int freer, png_uint_32 mask)
+{
+   png_debug(1, "in png_data_freer");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if (freer == PNG_DESTROY_WILL_FREE_DATA)
+      info_ptr->free_me |= mask;
+
+   else if (freer == PNG_USER_WILL_FREE_DATA)
+      info_ptr->free_me &= ~mask;
+
+   else
+      png_error(png_ptr, "Unknown freer parameter in png_data_freer");
+}
+
+void PNGAPI
+png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
+    int num)
+{
+   png_debug(1, "in png_free_data");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+#ifdef PNG_TEXT_SUPPORTED
+   /* Free text item num or (if num == -1) all text items */
+   if (info_ptr->text != NULL &&
+       ((mask & PNG_FREE_TEXT) & info_ptr->free_me) != 0)
+   {
+      if (num != -1)
+      {
+         png_free(png_ptr, info_ptr->text[num].key);
+         info_ptr->text[num].key = NULL;
+      }
+
+      else
+      {
+         int i;
+
+         for (i = 0; i < info_ptr->num_text; i++)
+            png_free(png_ptr, info_ptr->text[i].key);
+
+         png_free(png_ptr, info_ptr->text);
+         info_ptr->text = NULL;
+         info_ptr->num_text = 0;
+         info_ptr->max_text = 0;
+      }
+   }
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+   /* Free any tRNS entry */
+   if (((mask & PNG_FREE_TRNS) & info_ptr->free_me) != 0)
+   {
+      info_ptr->valid &= ~PNG_INFO_tRNS;
+      png_free(png_ptr, info_ptr->trans_alpha);
+      info_ptr->trans_alpha = NULL;
+      info_ptr->num_trans = 0;
+   }
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+   /* Free any sCAL entry */
+   if (((mask & PNG_FREE_SCAL) & info_ptr->free_me) != 0)
+   {
+      png_free(png_ptr, info_ptr->scal_s_width);
+      png_free(png_ptr, info_ptr->scal_s_height);
+      info_ptr->scal_s_width = NULL;
+      info_ptr->scal_s_height = NULL;
+      info_ptr->valid &= ~PNG_INFO_sCAL;
+   }
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+   /* Free any pCAL entry */
+   if (((mask & PNG_FREE_PCAL) & info_ptr->free_me) != 0)
+   {
+      png_free(png_ptr, info_ptr->pcal_purpose);
+      png_free(png_ptr, info_ptr->pcal_units);
+      info_ptr->pcal_purpose = NULL;
+      info_ptr->pcal_units = NULL;
+
+      if (info_ptr->pcal_params != NULL)
+         {
+            int i;
+
+            for (i = 0; i < info_ptr->pcal_nparams; i++)
+               png_free(png_ptr, info_ptr->pcal_params[i]);
+
+            png_free(png_ptr, info_ptr->pcal_params);
+            info_ptr->pcal_params = NULL;
+         }
+      info_ptr->valid &= ~PNG_INFO_pCAL;
+   }
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+   /* Free any profile entry */
+   if (((mask & PNG_FREE_ICCP) & info_ptr->free_me) != 0)
+   {
+      png_free(png_ptr, info_ptr->iccp_name);
+      png_free(png_ptr, info_ptr->iccp_profile);
+      info_ptr->iccp_name = NULL;
+      info_ptr->iccp_profile = NULL;
+      info_ptr->valid &= ~PNG_INFO_iCCP;
+   }
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+   /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
+   if (info_ptr->splt_palettes != NULL &&
+       ((mask & PNG_FREE_SPLT) & info_ptr->free_me) != 0)
+   {
+      if (num != -1)
+      {
+         png_free(png_ptr, info_ptr->splt_palettes[num].name);
+         png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+         info_ptr->splt_palettes[num].name = NULL;
+         info_ptr->splt_palettes[num].entries = NULL;
+      }
+
+      else
+      {
+         int i;
+
+         for (i = 0; i < info_ptr->splt_palettes_num; i++)
+         {
+            png_free(png_ptr, info_ptr->splt_palettes[i].name);
+            png_free(png_ptr, info_ptr->splt_palettes[i].entries);
+         }
+
+         png_free(png_ptr, info_ptr->splt_palettes);
+         info_ptr->splt_palettes = NULL;
+         info_ptr->splt_palettes_num = 0;
+         info_ptr->valid &= ~PNG_INFO_sPLT;
+      }
+   }
+#endif
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+   if (info_ptr->unknown_chunks != NULL &&
+       ((mask & PNG_FREE_UNKN) & info_ptr->free_me) != 0)
+   {
+      if (num != -1)
+      {
+          png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+          info_ptr->unknown_chunks[num].data = NULL;
+      }
+
+      else
+      {
+         int i;
+
+         for (i = 0; i < info_ptr->unknown_chunks_num; i++)
+            png_free(png_ptr, info_ptr->unknown_chunks[i].data);
+
+         png_free(png_ptr, info_ptr->unknown_chunks);
+         info_ptr->unknown_chunks = NULL;
+         info_ptr->unknown_chunks_num = 0;
+      }
+   }
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+   /* Free any eXIf entry */
+   if (((mask & PNG_FREE_EXIF) & info_ptr->free_me) != 0)
+   {
+# ifdef PNG_READ_eXIf_SUPPORTED
+      if (info_ptr->eXIf_buf)
+      {
+         png_free(png_ptr, info_ptr->eXIf_buf);
+         info_ptr->eXIf_buf = NULL;
+      }
+# endif
+      if (info_ptr->exif)
+      {
+         png_free(png_ptr, info_ptr->exif);
+         info_ptr->exif = NULL;
+      }
+      info_ptr->valid &= ~PNG_INFO_eXIf;
+   }
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+   /* Free any hIST entry */
+   if (((mask & PNG_FREE_HIST) & info_ptr->free_me) != 0)
+   {
+      png_free(png_ptr, info_ptr->hist);
+      info_ptr->hist = NULL;
+      info_ptr->valid &= ~PNG_INFO_hIST;
+   }
+#endif
+
+   /* Free any PLTE entry that was internally allocated */
+   if (((mask & PNG_FREE_PLTE) & info_ptr->free_me) != 0)
+   {
+      png_free(png_ptr, info_ptr->palette);
+      info_ptr->palette = NULL;
+      info_ptr->valid &= ~PNG_INFO_PLTE;
+      info_ptr->num_palette = 0;
+   }
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+   /* Free any image bits attached to the info structure */
+   if (((mask & PNG_FREE_ROWS) & info_ptr->free_me) != 0)
+   {
+      if (info_ptr->row_pointers != NULL)
+      {
+         png_uint_32 row;
+         for (row = 0; row < info_ptr->height; row++)
+            png_free(png_ptr, info_ptr->row_pointers[row]);
+
+         png_free(png_ptr, info_ptr->row_pointers);
+         info_ptr->row_pointers = NULL;
+      }
+      info_ptr->valid &= ~PNG_INFO_IDAT;
+   }
+#endif
+
+   if (num != -1)
+      mask &= ~PNG_FREE_MUL;
+
+   info_ptr->free_me &= ~mask;
+}
+#endif /* READ || WRITE */
+
+/* This function returns a pointer to the io_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy() or png_read_destroy() are called.
+ */
+png_voidp PNGAPI
+png_get_io_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+
+   return (png_ptr->io_ptr);
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#  ifdef PNG_STDIO_SUPPORTED
+/* Initialize the default input/output functions for the PNG file.  If you
+ * use your own read or write routines, you can call either png_set_read_fn()
+ * or png_set_write_fn() instead of png_init_io().  If you have defined
+ * PNG_NO_STDIO or otherwise disabled PNG_STDIO_SUPPORTED, you must use a
+ * function of your own because "FILE *" isn't necessarily available.
+ */
+void PNGAPI
+png_init_io(png_structrp png_ptr, png_FILE_p fp)
+{
+   png_debug(1, "in png_init_io");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->io_ptr = (png_voidp)fp;
+}
+#  endif
+
+#  ifdef PNG_SAVE_INT_32_SUPPORTED
+/* PNG signed integers are saved in 32-bit 2's complement format.  ANSI C-90
+ * defines a cast of a signed integer to an unsigned integer either to preserve
+ * the value, if it is positive, or to calculate:
+ *
+ *     (UNSIGNED_MAX+1) + integer
+ *
+ * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the
+ * negative integral value is added the result will be an unsigned value
+ * correspnding to the 2's complement representation.
+ */
+void PNGAPI
+png_save_int_32(png_bytep buf, png_int_32 i)
+{
+   png_save_uint_32(buf, (png_uint_32)i);
+}
+#  endif
+
+#  ifdef PNG_TIME_RFC1123_SUPPORTED
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+int PNGAPI
+png_convert_to_rfc1123_buffer(char out[29], png_const_timep ptime)
+{
+   static PNG_CONST char short_months[12][4] =
+        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+   if (out == NULL)
+      return 0;
+
+   if (ptime->year > 9999 /* RFC1123 limitation */ ||
+       ptime->month == 0    ||  ptime->month > 12  ||
+       ptime->day   == 0    ||  ptime->day   > 31  ||
+       ptime->hour  > 23    ||  ptime->minute > 59 ||
+       ptime->second > 60)
+      return 0;
+
+   {
+      size_t pos = 0;
+      char number_buf[5]; /* enough for a four-digit year */
+
+#     define APPEND_STRING(string) pos = png_safecat(out, 29, pos, (string))
+#     define APPEND_NUMBER(format, value)\
+         APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
+#     define APPEND(ch) if (pos < 28) out[pos++] = (ch)
+
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day);
+      APPEND(' ');
+      APPEND_STRING(short_months[(ptime->month - 1)]);
+      APPEND(' ');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year);
+      APPEND(' ');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour);
+      APPEND(':');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute);
+      APPEND(':');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second);
+      APPEND_STRING(" +0000"); /* This reliably terminates the buffer */
+      PNG_UNUSED (pos)
+
+#     undef APPEND
+#     undef APPEND_NUMBER
+#     undef APPEND_STRING
+   }
+
+   return 1;
+}
+
+#    if PNG_LIBPNG_VER < 10700
+/* To do: remove the following from libpng-1.7 */
+/* Original API that uses a private buffer in png_struct.
+ * Deprecated because it causes png_struct to carry a spurious temporary
+ * buffer (png_struct::time_buffer), better to have the caller pass this in.
+ */
+png_const_charp PNGAPI
+png_convert_to_rfc1123(png_structrp png_ptr, png_const_timep ptime)
+{
+   if (png_ptr != NULL)
+   {
+      /* The only failure above if png_ptr != NULL is from an invalid ptime */
+      if (png_convert_to_rfc1123_buffer(png_ptr->time_buffer, ptime) == 0)
+         png_warning(png_ptr, "Ignoring invalid time value");
+
+      else
+         return png_ptr->time_buffer;
+   }
+
+   return NULL;
+}
+#    endif /* LIBPNG_VER < 10700 */
+#  endif /* TIME_RFC1123 */
+
+#endif /* READ || WRITE */
+
+png_const_charp PNGAPI
+png_get_copyright(png_const_structrp png_ptr)
+{
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
+#ifdef PNG_STRING_COPYRIGHT
+   return PNG_STRING_COPYRIGHT
+#else
+#  ifdef __STDC__
+   return PNG_STRING_NEWLINE \
+      "libpng version 1.6.34 - September 29, 2017" PNG_STRING_NEWLINE \
+      "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \
+      PNG_STRING_NEWLINE \
+      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
+      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
+      PNG_STRING_NEWLINE;
+#  else
+   return "libpng version 1.6.34 - September 29, 2017\
+      Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\
+      Copyright (c) 1996-1997 Andreas Dilger\
+      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
+#  endif
+#endif
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz.  To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver().  Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_const_charp PNGAPI
+png_get_libpng_ver(png_const_structrp png_ptr)
+{
+   /* Version of *.c files used when building libpng */
+   return png_get_header_ver(png_ptr);
+}
+
+png_const_charp PNGAPI
+png_get_header_ver(png_const_structrp png_ptr)
+{
+   /* Version of *.h files used when building libpng */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
+   return PNG_LIBPNG_VER_STRING;
+}
+
+png_const_charp PNGAPI
+png_get_header_version(png_const_structrp png_ptr)
+{
+   /* Returns longer string containing both version and date */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
+#ifdef __STDC__
+   return PNG_HEADER_VERSION_STRING
+#  ifndef PNG_READ_SUPPORTED
+      " (NO READ SUPPORT)"
+#  endif
+      PNG_STRING_NEWLINE;
+#else
+   return PNG_HEADER_VERSION_STRING;
+#endif
+}
+
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+/* NOTE: this routine is not used internally! */
+/* Build a grayscale palette.  Palette is assumed to be 1 << bit_depth
+ * large of png_color.  This lets grayscale images be treated as
+ * paletted.  Most useful for gamma correction and simplification
+ * of code.  This API is not used internally.
+ */
+void PNGAPI
+png_build_grayscale_palette(int bit_depth, png_colorp palette)
+{
+   int num_palette;
+   int color_inc;
+   int i;
+   int v;
+
+   png_debug(1, "in png_do_build_grayscale_palette");
+
+   if (palette == NULL)
+      return;
+
+   switch (bit_depth)
+   {
+      case 1:
+         num_palette = 2;
+         color_inc = 0xff;
+         break;
+
+      case 2:
+         num_palette = 4;
+         color_inc = 0x55;
+         break;
+
+      case 4:
+         num_palette = 16;
+         color_inc = 0x11;
+         break;
+
+      case 8:
+         num_palette = 256;
+         color_inc = 1;
+         break;
+
+      default:
+         num_palette = 0;
+         color_inc = 0;
+         break;
+   }
+
+   for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
+   {
+      palette[i].red = (png_byte)(v & 0xff);
+      palette[i].green = (png_byte)(v & 0xff);
+      palette[i].blue = (png_byte)(v & 0xff);
+   }
+}
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
+{
+   /* Check chunk_name and return "keep" value if it's on the list, else 0 */
+   png_const_bytep p, p_end;
+
+   if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list == 0)
+      return PNG_HANDLE_CHUNK_AS_DEFAULT;
+
+   p_end = png_ptr->chunk_list;
+   p = p_end + png_ptr->num_chunk_list*5; /* beyond end */
+
+   /* The code is the fifth byte after each four byte string.  Historically this
+    * code was always searched from the end of the list, this is no longer
+    * necessary because the 'set' routine handles duplicate entries correcty.
+    */
+   do /* num_chunk_list > 0, so at least one */
+   {
+      p -= 5;
+
+      if (memcmp(chunk_name, p, 4) == 0)
+         return p[4];
+   }
+   while (p > p_end);
+
+   /* This means that known chunks should be processed and unknown chunks should
+    * be handled according to the value of png_ptr->unknown_default; this can be
+    * confusing because, as a result, there are two levels of defaulting for
+    * unknown chunks.
+    */
+   return PNG_HANDLE_CHUNK_AS_DEFAULT;
+}
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+   defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+int /* PRIVATE */
+png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
+{
+   png_byte chunk_string[5];
+
+   PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name);
+   return png_handle_as_unknown(png_ptr, chunk_string);
+}
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
+#endif /* SET_UNKNOWN_CHUNKS */
+
+#ifdef PNG_READ_SUPPORTED
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return Z_STREAM_ERROR;
+
+   /* WARNING: this resets the window bits to the maximum! */
+   return (inflateReset(&png_ptr->zstream));
+}
+#endif /* READ */
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+   /* Version of *.c files used when building libpng */
+   return((png_uint_32)PNG_LIBPNG_VER);
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Ensure that png_ptr->zstream.msg holds some appropriate error message string.
+ * If it doesn't 'ret' is used to set it to something appropriate, even in cases
+ * like Z_OK or Z_STREAM_END where the error code is apparently a success code.
+ */
+void /* PRIVATE */
+png_zstream_error(png_structrp png_ptr, int ret)
+{
+   /* Translate 'ret' into an appropriate error string, priority is given to the
+    * one in zstream if set.  This always returns a string, even in cases like
+    * Z_OK or Z_STREAM_END where the error code is a success code.
+    */
+   if (png_ptr->zstream.msg == NULL) switch (ret)
+   {
+      default:
+      case Z_OK:
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return code");
+         break;
+
+      case Z_STREAM_END:
+         /* Normal exit */
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected end of LZ stream");
+         break;
+
+      case Z_NEED_DICT:
+         /* This means the deflate stream did not have a dictionary; this
+          * indicates a bogus PNG.
+          */
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("missing LZ dictionary");
+         break;
+
+      case Z_ERRNO:
+         /* gz APIs only: should not happen */
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("zlib IO error");
+         break;
+
+      case Z_STREAM_ERROR:
+         /* internal libpng error */
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("bad parameters to zlib");
+         break;
+
+      case Z_DATA_ERROR:
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("damaged LZ stream");
+         break;
+
+      case Z_MEM_ERROR:
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("insufficient memory");
+         break;
+
+      case Z_BUF_ERROR:
+         /* End of input or output; not a problem if the caller is doing
+          * incremental read or write.
+          */
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("truncated");
+         break;
+
+      case Z_VERSION_ERROR:
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("unsupported zlib version");
+         break;
+
+      case PNG_UNEXPECTED_ZLIB_RETURN:
+         /* Compile errors here mean that zlib now uses the value co-opted in
+          * pngpriv.h for PNG_UNEXPECTED_ZLIB_RETURN; update the switch above
+          * and change pngpriv.h.  Note that this message is "... return",
+          * whereas the default/Z_OK one is "... return code".
+          */
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("unexpected zlib return");
+         break;
+   }
+}
+
+/* png_convert_size: a PNGAPI but no longer in png.h, so deleted
+ * at libpng 1.5.5!
+ */
+
+/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
+#ifdef PNG_GAMMA_SUPPORTED /* always set if COLORSPACE */
+static int
+png_colorspace_check_gamma(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, png_fixed_point gAMA, int from)
+   /* This is called to check a new gamma value against an existing one.  The
+    * routine returns false if the new gamma value should not be written.
+    *
+    * 'from' says where the new gamma value comes from:
+    *
+    *    0: the new gamma value is the libpng estimate for an ICC profile
+    *    1: the new gamma value comes from a gAMA chunk
+    *    2: the new gamma value comes from an sRGB chunk
+    */
+{
+   png_fixed_point gtest;
+
+   if ((colorspace->flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+       (png_muldiv(&gtest, colorspace->gamma, PNG_FP_1, gAMA) == 0  ||
+      png_gamma_significant(gtest) != 0))
+   {
+      /* Either this is an sRGB image, in which case the calculated gamma
+       * approximation should match, or this is an image with a profile and the
+       * value libpng calculates for the gamma of the profile does not match the
+       * value recorded in the file.  The former, sRGB, case is an error, the
+       * latter is just a warning.
+       */
+      if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0 || from == 2)
+      {
+         png_chunk_report(png_ptr, "gamma value does not match sRGB",
+             PNG_CHUNK_ERROR);
+         /* Do not overwrite an sRGB value */
+         return from == 2;
+      }
+
+      else /* sRGB tag not involved */
+      {
+         png_chunk_report(png_ptr, "gamma value does not match libpng estimate",
+             PNG_CHUNK_WARNING);
+         return from == 1;
+      }
+   }
+
+   return 1;
+}
+
+void /* PRIVATE */
+png_colorspace_set_gamma(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, png_fixed_point gAMA)
+{
+   /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
+    * occur.  Since the fixed point representation is asymetrical it is
+    * possible for 1/gamma to overflow the limit of 21474 and this means the
+    * gamma value must be at least 5/100000 and hence at most 20000.0.  For
+    * safety the limits here are a little narrower.  The values are 0.00016 to
+    * 6250.0, which are truly ridiculous gamma values (and will produce
+    * displays that are all black or all white.)
+    *
+    * In 1.6.0 this test replaces the ones in pngrutil.c, in the gAMA chunk
+    * handling code, which only required the value to be >0.
+    */
+   png_const_charp errmsg;
+
+   if (gAMA < 16 || gAMA > 625000000)
+      errmsg = "gamma value out of range";
+
+#  ifdef PNG_READ_gAMA_SUPPORTED
+   /* Allow the application to set the gamma value more than once */
+   else if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+      (colorspace->flags & PNG_COLORSPACE_FROM_gAMA) != 0)
+      errmsg = "duplicate";
+#  endif
+
+   /* Do nothing if the colorspace is already invalid */
+   else if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+      return;
+
+   else
+   {
+      if (png_colorspace_check_gamma(png_ptr, colorspace, gAMA,
+          1/*from gAMA*/) != 0)
+      {
+         /* Store this gamma value. */
+         colorspace->gamma = gAMA;
+         colorspace->flags |=
+            (PNG_COLORSPACE_HAVE_GAMMA | PNG_COLORSPACE_FROM_gAMA);
+      }
+
+      /* At present if the check_gamma test fails the gamma of the colorspace is
+       * not updated however the colorspace is not invalidated.  This
+       * corresponds to the case where the existing gamma comes from an sRGB
+       * chunk or profile.  An error message has already been output.
+       */
+      return;
+   }
+
+   /* Error exit - errmsg has been set. */
+   colorspace->flags |= PNG_COLORSPACE_INVALID;
+   png_chunk_report(png_ptr, errmsg, PNG_CHUNK_WRITE_ERROR);
+}
+
+void /* PRIVATE */
+png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr)
+{
+   if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+   {
+      /* Everything is invalid */
+      info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB|
+         PNG_INFO_iCCP);
+
+#     ifdef PNG_COLORSPACE_SUPPORTED
+      /* Clean up the iCCP profile now if it won't be used. */
+      png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, -1/*not used*/);
+#     else
+      PNG_UNUSED(png_ptr)
+#     endif
+   }
+
+   else
+   {
+#     ifdef PNG_COLORSPACE_SUPPORTED
+      /* Leave the INFO_iCCP flag set if the pngset.c code has already set
+       * it; this allows a PNG to contain a profile which matches sRGB and
+       * yet still have that profile retrievable by the application.
+       */
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_MATCHES_sRGB) != 0)
+         info_ptr->valid |= PNG_INFO_sRGB;
+
+      else
+         info_ptr->valid &= ~PNG_INFO_sRGB;
+
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+         info_ptr->valid |= PNG_INFO_cHRM;
+
+      else
+         info_ptr->valid &= ~PNG_INFO_cHRM;
+#     endif
+
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0)
+         info_ptr->valid |= PNG_INFO_gAMA;
+
+      else
+         info_ptr->valid &= ~PNG_INFO_gAMA;
+   }
+}
+
+#ifdef PNG_READ_SUPPORTED
+void /* PRIVATE */
+png_colorspace_sync(png_const_structrp png_ptr, png_inforp info_ptr)
+{
+   if (info_ptr == NULL) /* reduce code size; check here not in the caller */
+      return;
+
+   info_ptr->colorspace = png_ptr->colorspace;
+   png_colorspace_sync_info(png_ptr, info_ptr);
+}
+#endif
+#endif /* GAMMA */
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* Added at libpng-1.5.5 to support read and write of true CIEXYZ values for
+ * cHRM, as opposed to using chromaticities.  These internal APIs return
+ * non-zero on a parameter error.  The X, Y and Z values are required to be
+ * positive and less than 1.0.
+ */
+static int
+png_xy_from_XYZ(png_xy *xy, const png_XYZ *XYZ)
+{
+   png_int_32 d, dwhite, whiteX, whiteY;
+
+   d = XYZ->red_X + XYZ->red_Y + XYZ->red_Z;
+   if (png_muldiv(&xy->redx, XYZ->red_X, PNG_FP_1, d) == 0)
+      return 1;
+   if (png_muldiv(&xy->redy, XYZ->red_Y, PNG_FP_1, d) == 0)
+      return 1;
+   dwhite = d;
+   whiteX = XYZ->red_X;
+   whiteY = XYZ->red_Y;
+
+   d = XYZ->green_X + XYZ->green_Y + XYZ->green_Z;
+   if (png_muldiv(&xy->greenx, XYZ->green_X, PNG_FP_1, d) == 0)
+      return 1;
+   if (png_muldiv(&xy->greeny, XYZ->green_Y, PNG_FP_1, d) == 0)
+      return 1;
+   dwhite += d;
+   whiteX += XYZ->green_X;
+   whiteY += XYZ->green_Y;
+
+   d = XYZ->blue_X + XYZ->blue_Y + XYZ->blue_Z;
+   if (png_muldiv(&xy->bluex, XYZ->blue_X, PNG_FP_1, d) == 0)
+      return 1;
+   if (png_muldiv(&xy->bluey, XYZ->blue_Y, PNG_FP_1, d) == 0)
+      return 1;
+   dwhite += d;
+   whiteX += XYZ->blue_X;
+   whiteY += XYZ->blue_Y;
+
+   /* The reference white is simply the sum of the end-point (X,Y,Z) vectors,
+    * thus:
+    */
+   if (png_muldiv(&xy->whitex, whiteX, PNG_FP_1, dwhite) == 0)
+      return 1;
+   if (png_muldiv(&xy->whitey, whiteY, PNG_FP_1, dwhite) == 0)
+      return 1;
+
+   return 0;
+}
+
+static int
+png_XYZ_from_xy(png_XYZ *XYZ, const png_xy *xy)
+{
+   png_fixed_point red_inverse, green_inverse, blue_scale;
+   png_fixed_point left, right, denominator;
+
+   /* Check xy and, implicitly, z.  Note that wide gamut color spaces typically
+    * have end points with 0 tristimulus values (these are impossible end
+    * points, but they are used to cover the possible colors).  We check
+    * xy->whitey against 5, not 0, to avoid a possible integer overflow.
+    */
+   if (xy->redx   < 0 || xy->redx > PNG_FP_1) return 1;
+   if (xy->redy   < 0 || xy->redy > PNG_FP_1-xy->redx) return 1;
+   if (xy->greenx < 0 || xy->greenx > PNG_FP_1) return 1;
+   if (xy->greeny < 0 || xy->greeny > PNG_FP_1-xy->greenx) return 1;
+   if (xy->bluex  < 0 || xy->bluex > PNG_FP_1) return 1;
+   if (xy->bluey  < 0 || xy->bluey > PNG_FP_1-xy->bluex) return 1;
+   if (xy->whitex < 0 || xy->whitex > PNG_FP_1) return 1;
+   if (xy->whitey < 5 || xy->whitey > PNG_FP_1-xy->whitex) return 1;
+
+   /* The reverse calculation is more difficult because the original tristimulus
+    * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8
+    * derived values were recorded in the cHRM chunk;
+    * (red,green,blue,white)x(x,y).  This loses one degree of freedom and
+    * therefore an arbitrary ninth value has to be introduced to undo the
+    * original transformations.
+    *
+    * Think of the original end-points as points in (X,Y,Z) space.  The
+    * chromaticity values (c) have the property:
+    *
+    *           C
+    *   c = ---------
+    *       X + Y + Z
+    *
+    * For each c (x,y,z) from the corresponding original C (X,Y,Z).  Thus the
+    * three chromaticity values (x,y,z) for each end-point obey the
+    * relationship:
+    *
+    *   x + y + z = 1
+    *
+    * This describes the plane in (X,Y,Z) space that intersects each axis at the
+    * value 1.0; call this the chromaticity plane.  Thus the chromaticity
+    * calculation has scaled each end-point so that it is on the x+y+z=1 plane
+    * and chromaticity is the intersection of the vector from the origin to the
+    * (X,Y,Z) value with the chromaticity plane.
+    *
+    * To fully invert the chromaticity calculation we would need the three
+    * end-point scale factors, (red-scale, green-scale, blue-scale), but these
+    * were not recorded.  Instead we calculated the reference white (X,Y,Z) and
+    * recorded the chromaticity of this.  The reference white (X,Y,Z) would have
+    * given all three of the scale factors since:
+    *
+    *    color-C = color-c * color-scale
+    *    white-C = red-C + green-C + blue-C
+    *            = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+    *
+    * But cHRM records only white-x and white-y, so we have lost the white scale
+    * factor:
+    *
+    *    white-C = white-c*white-scale
+    *
+    * To handle this the inverse transformation makes an arbitrary assumption
+    * about white-scale:
+    *
+    *    Assume: white-Y = 1.0
+    *    Hence:  white-scale = 1/white-y
+    *    Or:     red-Y + green-Y + blue-Y = 1.0
+    *
+    * Notice the last statement of the assumption gives an equation in three of
+    * the nine values we want to calculate.  8 more equations come from the
+    * above routine as summarised at the top above (the chromaticity
+    * calculation):
+    *
+    *    Given: color-x = color-X / (color-X + color-Y + color-Z)
+    *    Hence: (color-x - 1)*color-X + color.x*color-Y + color.x*color-Z = 0
+    *
+    * This is 9 simultaneous equations in the 9 variables "color-C" and can be
+    * solved by Cramer's rule.  Cramer's rule requires calculating 10 9x9 matrix
+    * determinants, however this is not as bad as it seems because only 28 of
+    * the total of 90 terms in the various matrices are non-zero.  Nevertheless
+    * Cramer's rule is notoriously numerically unstable because the determinant
+    * calculation involves the difference of large, but similar, numbers.  It is
+    * difficult to be sure that the calculation is stable for real world values
+    * and it is certain that it becomes unstable where the end points are close
+    * together.
+    *
+    * So this code uses the perhaps slightly less optimal but more
+    * understandable and totally obvious approach of calculating color-scale.
+    *
+    * This algorithm depends on the precision in white-scale and that is
+    * (1/white-y), so we can immediately see that as white-y approaches 0 the
+    * accuracy inherent in the cHRM chunk drops off substantially.
+    *
+    * libpng arithmetic: a simple inversion of the above equations
+    * ------------------------------------------------------------
+    *
+    *    white_scale = 1/white-y
+    *    white-X = white-x * white-scale
+    *    white-Y = 1.0
+    *    white-Z = (1 - white-x - white-y) * white_scale
+    *
+    *    white-C = red-C + green-C + blue-C
+    *            = red-c*red-scale + green-c*green-scale + blue-c*blue-scale
+    *
+    * This gives us three equations in (red-scale,green-scale,blue-scale) where
+    * all the coefficients are now known:
+    *
+    *    red-x*red-scale + green-x*green-scale + blue-x*blue-scale
+    *       = white-x/white-y
+    *    red-y*red-scale + green-y*green-scale + blue-y*blue-scale = 1
+    *    red-z*red-scale + green-z*green-scale + blue-z*blue-scale
+    *       = (1 - white-x - white-y)/white-y
+    *
+    * In the last equation color-z is (1 - color-x - color-y) so we can add all
+    * three equations together to get an alternative third:
+    *
+    *    red-scale + green-scale + blue-scale = 1/white-y = white-scale
+    *
+    * So now we have a Cramer's rule solution where the determinants are just
+    * 3x3 - far more tractible.  Unfortunately 3x3 determinants still involve
+    * multiplication of three coefficients so we can't guarantee to avoid
+    * overflow in the libpng fixed point representation.  Using Cramer's rule in
+    * floating point is probably a good choice here, but it's not an option for
+    * fixed point.  Instead proceed to simplify the first two equations by
+    * eliminating what is likely to be the largest value, blue-scale:
+    *
+    *    blue-scale = white-scale - red-scale - green-scale
+    *
+    * Hence:
+    *
+    *    (red-x - blue-x)*red-scale + (green-x - blue-x)*green-scale =
+    *                (white-x - blue-x)*white-scale
+    *
+    *    (red-y - blue-y)*red-scale + (green-y - blue-y)*green-scale =
+    *                1 - blue-y*white-scale
+    *
+    * And now we can trivially solve for (red-scale,green-scale):
+    *
+    *    green-scale =
+    *                (white-x - blue-x)*white-scale - (red-x - blue-x)*red-scale
+    *                -----------------------------------------------------------
+    *                                  green-x - blue-x
+    *
+    *    red-scale =
+    *                1 - blue-y*white-scale - (green-y - blue-y) * green-scale
+    *                ---------------------------------------------------------
+    *                                  red-y - blue-y
+    *
+    * Hence:
+    *
+    *    red-scale =
+    *          ( (green-x - blue-x) * (white-y - blue-y) -
+    *            (green-y - blue-y) * (white-x - blue-x) ) / white-y
+    * -------------------------------------------------------------------------
+    *  (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+    *
+    *    green-scale =
+    *          ( (red-y - blue-y) * (white-x - blue-x) -
+    *            (red-x - blue-x) * (white-y - blue-y) ) / white-y
+    * -------------------------------------------------------------------------
+    *  (green-x - blue-x)*(red-y - blue-y)-(green-y - blue-y)*(red-x - blue-x)
+    *
+    * Accuracy:
+    * The input values have 5 decimal digits of accuracy.  The values are all in
+    * the range 0 < value < 1, so simple products are in the same range but may
+    * need up to 10 decimal digits to preserve the original precision and avoid
+    * underflow.  Because we are using a 32-bit signed representation we cannot
+    * match this; the best is a little over 9 decimal digits, less than 10.
+    *
+    * The approach used here is to preserve the maximum precision within the
+    * signed representation.  Because the red-scale calculation above uses the
+    * difference between two products of values that must be in the range -1..+1
+    * it is sufficient to divide the product by 7; ceil(100,000/32767*2).  The
+    * factor is irrelevant in the calculation because it is applied to both
+    * numerator and denominator.
+    *
+    * Note that the values of the differences of the products of the
+    * chromaticities in the above equations tend to be small, for example for
+    * the sRGB chromaticities they are:
+    *
+    * red numerator:    -0.04751
+    * green numerator:  -0.08788
+    * denominator:      -0.2241 (without white-y multiplication)
+    *
+    *  The resultant Y coefficients from the chromaticities of some widely used
+    *  color space definitions are (to 15 decimal places):
+    *
+    *  sRGB
+    *    0.212639005871510 0.715168678767756 0.072192315360734
+    *  Kodak ProPhoto
+    *    0.288071128229293 0.711843217810102 0.000085653960605
+    *  Adobe RGB
+    *    0.297344975250536 0.627363566255466 0.075291458493998
+    *  Adobe Wide Gamut RGB
+    *    0.258728243040113 0.724682314948566 0.016589442011321
+    */
+   /* By the argument, above overflow should be impossible here. The return
+    * value of 2 indicates an internal error to the caller.
+    */
+   if (png_muldiv(&left, xy->greenx-xy->bluex, xy->redy - xy->bluey, 7) == 0)
+      return 2;
+   if (png_muldiv(&right, xy->greeny-xy->bluey, xy->redx - xy->bluex, 7) == 0)
+      return 2;
+   denominator = left - right;
+
+   /* Now find the red numerator. */
+   if (png_muldiv(&left, xy->greenx-xy->bluex, xy->whitey-xy->bluey, 7) == 0)
+      return 2;
+   if (png_muldiv(&right, xy->greeny-xy->bluey, xy->whitex-xy->bluex, 7) == 0)
+      return 2;
+
+   /* Overflow is possible here and it indicates an extreme set of PNG cHRM
+    * chunk values.  This calculation actually returns the reciprocal of the
+    * scale value because this allows us to delay the multiplication of white-y
+    * into the denominator, which tends to produce a small number.
+    */
+   if (png_muldiv(&red_inverse, xy->whitey, denominator, left-right) == 0 ||
+       red_inverse <= xy->whitey /* r+g+b scales = white scale */)
+      return 1;
+
+   /* Similarly for green_inverse: */
+   if (png_muldiv(&left, xy->redy-xy->bluey, xy->whitex-xy->bluex, 7) == 0)
+      return 2;
+   if (png_muldiv(&right, xy->redx-xy->bluex, xy->whitey-xy->bluey, 7) == 0)
+      return 2;
+   if (png_muldiv(&green_inverse, xy->whitey, denominator, left-right) == 0 ||
+       green_inverse <= xy->whitey)
+      return 1;
+
+   /* And the blue scale, the checks above guarantee this can't overflow but it
+    * can still produce 0 for extreme cHRM values.
+    */
+   blue_scale = png_reciprocal(xy->whitey) - png_reciprocal(red_inverse) -
+       png_reciprocal(green_inverse);
+   if (blue_scale <= 0)
+      return 1;
+
+
+   /* And fill in the png_XYZ: */
+   if (png_muldiv(&XYZ->red_X, xy->redx, PNG_FP_1, red_inverse) == 0)
+      return 1;
+   if (png_muldiv(&XYZ->red_Y, xy->redy, PNG_FP_1, red_inverse) == 0)
+      return 1;
+   if (png_muldiv(&XYZ->red_Z, PNG_FP_1 - xy->redx - xy->redy, PNG_FP_1,
+       red_inverse) == 0)
+      return 1;
+
+   if (png_muldiv(&XYZ->green_X, xy->greenx, PNG_FP_1, green_inverse) == 0)
+      return 1;
+   if (png_muldiv(&XYZ->green_Y, xy->greeny, PNG_FP_1, green_inverse) == 0)
+      return 1;
+   if (png_muldiv(&XYZ->green_Z, PNG_FP_1 - xy->greenx - xy->greeny, PNG_FP_1,
+       green_inverse) == 0)
+      return 1;
+
+   if (png_muldiv(&XYZ->blue_X, xy->bluex, blue_scale, PNG_FP_1) == 0)
+      return 1;
+   if (png_muldiv(&XYZ->blue_Y, xy->bluey, blue_scale, PNG_FP_1) == 0)
+      return 1;
+   if (png_muldiv(&XYZ->blue_Z, PNG_FP_1 - xy->bluex - xy->bluey, blue_scale,
+       PNG_FP_1) == 0)
+      return 1;
+
+   return 0; /*success*/
+}
+
+static int
+png_XYZ_normalize(png_XYZ *XYZ)
+{
+   png_int_32 Y;
+
+   if (XYZ->red_Y < 0 || XYZ->green_Y < 0 || XYZ->blue_Y < 0 ||
+      XYZ->red_X < 0 || XYZ->green_X < 0 || XYZ->blue_X < 0 ||
+      XYZ->red_Z < 0 || XYZ->green_Z < 0 || XYZ->blue_Z < 0)
+      return 1;
+
+   /* Normalize by scaling so the sum of the end-point Y values is PNG_FP_1.
+    * IMPLEMENTATION NOTE: ANSI requires signed overflow not to occur, therefore
+    * relying on addition of two positive values producing a negative one is not
+    * safe.
+    */
+   Y = XYZ->red_Y;
+   if (0x7fffffff - Y < XYZ->green_X)
+      return 1;
+   Y += XYZ->green_Y;
+   if (0x7fffffff - Y < XYZ->blue_X)
+      return 1;
+   Y += XYZ->blue_Y;
+
+   if (Y != PNG_FP_1)
+   {
+      if (png_muldiv(&XYZ->red_X, XYZ->red_X, PNG_FP_1, Y) == 0)
+         return 1;
+      if (png_muldiv(&XYZ->red_Y, XYZ->red_Y, PNG_FP_1, Y) == 0)
+         return 1;
+      if (png_muldiv(&XYZ->red_Z, XYZ->red_Z, PNG_FP_1, Y) == 0)
+         return 1;
+
+      if (png_muldiv(&XYZ->green_X, XYZ->green_X, PNG_FP_1, Y) == 0)
+         return 1;
+      if (png_muldiv(&XYZ->green_Y, XYZ->green_Y, PNG_FP_1, Y) == 0)
+         return 1;
+      if (png_muldiv(&XYZ->green_Z, XYZ->green_Z, PNG_FP_1, Y) == 0)
+         return 1;
+
+      if (png_muldiv(&XYZ->blue_X, XYZ->blue_X, PNG_FP_1, Y) == 0)
+         return 1;
+      if (png_muldiv(&XYZ->blue_Y, XYZ->blue_Y, PNG_FP_1, Y) == 0)
+         return 1;
+      if (png_muldiv(&XYZ->blue_Z, XYZ->blue_Z, PNG_FP_1, Y) == 0)
+         return 1;
+   }
+
+   return 0;
+}
+
+static int
+png_colorspace_endpoints_match(const png_xy *xy1, const png_xy *xy2, int delta)
+{
+   /* Allow an error of +/-0.01 (absolute value) on each chromaticity */
+   if (PNG_OUT_OF_RANGE(xy1->whitex, xy2->whitex,delta) ||
+       PNG_OUT_OF_RANGE(xy1->whitey, xy2->whitey,delta) ||
+       PNG_OUT_OF_RANGE(xy1->redx,   xy2->redx,  delta) ||
+       PNG_OUT_OF_RANGE(xy1->redy,   xy2->redy,  delta) ||
+       PNG_OUT_OF_RANGE(xy1->greenx, xy2->greenx,delta) ||
+       PNG_OUT_OF_RANGE(xy1->greeny, xy2->greeny,delta) ||
+       PNG_OUT_OF_RANGE(xy1->bluex,  xy2->bluex, delta) ||
+       PNG_OUT_OF_RANGE(xy1->bluey,  xy2->bluey, delta))
+      return 0;
+   return 1;
+}
+
+/* Added in libpng-1.6.0, a different check for the validity of a set of cHRM
+ * chunk chromaticities.  Earlier checks used to simply look for the overflow
+ * condition (where the determinant of the matrix to solve for XYZ ends up zero
+ * because the chromaticity values are not all distinct.)  Despite this it is
+ * theoretically possible to produce chromaticities that are apparently valid
+ * but that rapidly degrade to invalid, potentially crashing, sets because of
+ * arithmetic inaccuracies when calculations are performed on them.  The new
+ * check is to round-trip xy -> XYZ -> xy and then check that the result is
+ * within a small percentage of the original.
+ */
+static int
+png_colorspace_check_xy(png_XYZ *XYZ, const png_xy *xy)
+{
+   int result;
+   png_xy xy_test;
+
+   /* As a side-effect this routine also returns the XYZ endpoints. */
+   result = png_XYZ_from_xy(XYZ, xy);
+   if (result != 0)
+      return result;
+
+   result = png_xy_from_XYZ(&xy_test, XYZ);
+   if (result != 0)
+      return result;
+
+   if (png_colorspace_endpoints_match(xy, &xy_test,
+       5/*actually, the math is pretty accurate*/) != 0)
+      return 0;
+
+   /* Too much slip */
+   return 1;
+}
+
+/* This is the check going the other way.  The XYZ is modified to normalize it
+ * (another side-effect) and the xy chromaticities are returned.
+ */
+static int
+png_colorspace_check_XYZ(png_xy *xy, png_XYZ *XYZ)
+{
+   int result;
+   png_XYZ XYZtemp;
+
+   result = png_XYZ_normalize(XYZ);
+   if (result != 0)
+      return result;
+
+   result = png_xy_from_XYZ(xy, XYZ);
+   if (result != 0)
+      return result;
+
+   XYZtemp = *XYZ;
+   return png_colorspace_check_xy(&XYZtemp, xy);
+}
+
+/* Used to check for an endpoint match against sRGB */
+static const png_xy sRGB_xy = /* From ITU-R BT.709-3 */
+{
+   /* color      x       y */
+   /* red   */ 64000, 33000,
+   /* green */ 30000, 60000,
+   /* blue  */ 15000,  6000,
+   /* white */ 31270, 32900
+};
+
+static int
+png_colorspace_set_xy_and_XYZ(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, const png_xy *xy, const png_XYZ *XYZ,
+    int preferred)
+{
+   if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+      return 0;
+
+   /* The consistency check is performed on the chromaticities; this factors out
+    * variations because of the normalization (or not) of the end point Y
+    * values.
+    */
+   if (preferred < 2 &&
+       (colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      /* The end points must be reasonably close to any we already have.  The
+       * following allows an error of up to +/-.001
+       */
+      if (png_colorspace_endpoints_match(xy, &colorspace->end_points_xy,
+          100) == 0)
+      {
+         colorspace->flags |= PNG_COLORSPACE_INVALID;
+         png_benign_error(png_ptr, "inconsistent chromaticities");
+         return 0; /* failed */
+      }
+
+      /* Only overwrite with preferred values */
+      if (preferred == 0)
+         return 1; /* ok, but no change */
+   }
+
+   colorspace->end_points_xy = *xy;
+   colorspace->end_points_XYZ = *XYZ;
+   colorspace->flags |= PNG_COLORSPACE_HAVE_ENDPOINTS;
+
+   /* The end points are normally quoted to two decimal digits, so allow +/-0.01
+    * on this test.
+    */
+   if (png_colorspace_endpoints_match(xy, &sRGB_xy, 1000) != 0)
+      colorspace->flags |= PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB;
+
+   else
+      colorspace->flags &= PNG_COLORSPACE_CANCEL(
+         PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB);
+
+   return 2; /* ok and changed */
+}
+
+int /* PRIVATE */
+png_colorspace_set_chromaticities(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, const png_xy *xy, int preferred)
+{
+   /* We must check the end points to ensure they are reasonable - in the past
+    * color management systems have crashed as a result of getting bogus
+    * colorant values, while this isn't the fault of libpng it is the
+    * responsibility of libpng because PNG carries the bomb and libpng is in a
+    * position to protect against it.
+    */
+   png_XYZ XYZ;
+
+   switch (png_colorspace_check_xy(&XYZ, xy))
+   {
+      case 0: /* success */
+         return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, xy, &XYZ,
+             preferred);
+
+      case 1:
+         /* We can't invert the chromaticities so we can't produce value XYZ
+          * values.  Likely as not a color management system will fail too.
+          */
+         colorspace->flags |= PNG_COLORSPACE_INVALID;
+         png_benign_error(png_ptr, "invalid chromaticities");
+         break;
+
+      default:
+         /* libpng is broken; this should be a warning but if it happens we
+          * want error reports so for the moment it is an error.
+          */
+         colorspace->flags |= PNG_COLORSPACE_INVALID;
+         png_error(png_ptr, "internal error checking chromaticities");
+   }
+
+   return 0; /* failed */
+}
+
+int /* PRIVATE */
+png_colorspace_set_endpoints(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, const png_XYZ *XYZ_in, int preferred)
+{
+   png_XYZ XYZ = *XYZ_in;
+   png_xy xy;
+
+   switch (png_colorspace_check_XYZ(&xy, &XYZ))
+   {
+      case 0:
+         return png_colorspace_set_xy_and_XYZ(png_ptr, colorspace, &xy, &XYZ,
+             preferred);
+
+      case 1:
+         /* End points are invalid. */
+         colorspace->flags |= PNG_COLORSPACE_INVALID;
+         png_benign_error(png_ptr, "invalid end points");
+         break;
+
+      default:
+         colorspace->flags |= PNG_COLORSPACE_INVALID;
+         png_error(png_ptr, "internal error checking chromaticities");
+   }
+
+   return 0; /* failed */
+}
+
+#if defined(PNG_sRGB_SUPPORTED) || defined(PNG_iCCP_SUPPORTED)
+/* Error message generation */
+static char
+png_icc_tag_char(png_uint_32 byte)
+{
+   byte &= 0xff;
+   if (byte >= 32 && byte <= 126)
+      return (char)byte;
+   else
+      return '?';
+}
+
+static void
+png_icc_tag_name(char *name, png_uint_32 tag)
+{
+   name[0] = '\'';
+   name[1] = png_icc_tag_char(tag >> 24);
+   name[2] = png_icc_tag_char(tag >> 16);
+   name[3] = png_icc_tag_char(tag >>  8);
+   name[4] = png_icc_tag_char(tag      );
+   name[5] = '\'';
+}
+
+static int
+is_ICC_signature_char(png_alloc_size_t it)
+{
+   return it == 32 || (it >= 48 && it <= 57) || (it >= 65 && it <= 90) ||
+      (it >= 97 && it <= 122);
+}
+
+static int
+is_ICC_signature(png_alloc_size_t it)
+{
+   return is_ICC_signature_char(it >> 24) /* checks all the top bits */ &&
+      is_ICC_signature_char((it >> 16) & 0xff) &&
+      is_ICC_signature_char((it >> 8) & 0xff) &&
+      is_ICC_signature_char(it & 0xff);
+}
+
+static int
+png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_alloc_size_t value, png_const_charp reason)
+{
+   size_t pos;
+   char message[196]; /* see below for calculation */
+
+   if (colorspace != NULL)
+      colorspace->flags |= PNG_COLORSPACE_INVALID;
+
+   pos = png_safecat(message, (sizeof message), 0, "profile '"); /* 9 chars */
+   pos = png_safecat(message, pos+79, pos, name); /* Truncate to 79 chars */
+   pos = png_safecat(message, (sizeof message), pos, "': "); /* +2 = 90 */
+   if (is_ICC_signature(value) != 0)
+   {
+      /* So 'value' is at most 4 bytes and the following cast is safe */
+      png_icc_tag_name(message+pos, (png_uint_32)value);
+      pos += 6; /* total +8; less than the else clause */
+      message[pos++] = ':';
+      message[pos++] = ' ';
+   }
+#  ifdef PNG_WARNINGS_SUPPORTED
+   else
+      {
+         char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/
+
+         pos = png_safecat(message, (sizeof message), pos,
+             png_format_number(number, number+(sizeof number),
+             PNG_NUMBER_FORMAT_x, value));
+         pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/
+      }
+#  endif
+   /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
+   pos = png_safecat(message, (sizeof message), pos, reason);
+   PNG_UNUSED(pos)
+
+   /* This is recoverable, but make it unconditionally an app_error on write to
+    * avoid writing invalid ICC profiles into PNG files (i.e., we handle them
+    * on read, with a warning, but on write unless the app turns off
+    * application errors the PNG won't be written.)
+    */
+   png_chunk_report(png_ptr, message,
+       (colorspace != NULL) ? PNG_CHUNK_ERROR : PNG_CHUNK_WRITE_ERROR);
+
+   return 0;
+}
+#endif /* sRGB || iCCP */
+
+#ifdef PNG_sRGB_SUPPORTED
+int /* PRIVATE */
+png_colorspace_set_sRGB(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    int intent)
+{
+   /* sRGB sets known gamma, end points and (from the chunk) intent. */
+   /* IMPORTANT: these are not necessarily the values found in an ICC profile
+    * because ICC profiles store values adapted to a D50 environment; it is
+    * expected that the ICC profile mediaWhitePointTag will be D50; see the
+    * checks and code elsewhere to understand this better.
+    *
+    * These XYZ values, which are accurate to 5dp, produce rgb to gray
+    * coefficients of (6968,23435,2366), which are reduced (because they add up
+    * to 32769 not 32768) to (6968,23434,2366).  These are the values that
+    * libpng has traditionally used (and are the best values given the 15bit
+    * algorithm used by the rgb to gray code.)
+    */
+   static const png_XYZ sRGB_XYZ = /* D65 XYZ (*not* the D50 adapted values!) */
+   {
+      /* color      X      Y      Z */
+      /* red   */ 41239, 21264,  1933,
+      /* green */ 35758, 71517, 11919,
+      /* blue  */ 18048,  7219, 95053
+   };
+
+   /* Do nothing if the colorspace is already invalidated. */
+   if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+      return 0;
+
+   /* Check the intent, then check for existing settings.  It is valid for the
+    * PNG file to have cHRM or gAMA chunks along with sRGB, but the values must
+    * be consistent with the correct values.  If, however, this function is
+    * called below because an iCCP chunk matches sRGB then it is quite
+    * conceivable that an older app recorded incorrect gAMA and cHRM because of
+    * an incorrect calculation based on the values in the profile - this does
+    * *not* invalidate the profile (though it still produces an error, which can
+    * be ignored.)
+    */
+   if (intent < 0 || intent >= PNG_sRGB_INTENT_LAST)
+      return png_icc_profile_error(png_ptr, colorspace, "sRGB",
+          (png_alloc_size_t)intent, "invalid sRGB rendering intent");
+
+   if ((colorspace->flags & PNG_COLORSPACE_HAVE_INTENT) != 0 &&
+       colorspace->rendering_intent != intent)
+      return png_icc_profile_error(png_ptr, colorspace, "sRGB",
+         (png_alloc_size_t)intent, "inconsistent rendering intents");
+
+   if ((colorspace->flags & PNG_COLORSPACE_FROM_sRGB) != 0)
+   {
+      png_benign_error(png_ptr, "duplicate sRGB information ignored");
+      return 0;
+   }
+
+   /* If the standard sRGB cHRM chunk does not match the one from the PNG file
+    * warn but overwrite the value with the correct one.
+    */
+   if ((colorspace->flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0 &&
+       !png_colorspace_endpoints_match(&sRGB_xy, &colorspace->end_points_xy,
+       100))
+      png_chunk_report(png_ptr, "cHRM chunk does not match sRGB",
+         PNG_CHUNK_ERROR);
+
+   /* This check is just done for the error reporting - the routine always
+    * returns true when the 'from' argument corresponds to sRGB (2).
+    */
+   (void)png_colorspace_check_gamma(png_ptr, colorspace, PNG_GAMMA_sRGB_INVERSE,
+       2/*from sRGB*/);
+
+   /* intent: bugs in GCC force 'int' to be used as the parameter type. */
+   colorspace->rendering_intent = (png_uint_16)intent;
+   colorspace->flags |= PNG_COLORSPACE_HAVE_INTENT;
+
+   /* endpoints */
+   colorspace->end_points_xy = sRGB_xy;
+   colorspace->end_points_XYZ = sRGB_XYZ;
+   colorspace->flags |=
+      (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB);
+
+   /* gamma */
+   colorspace->gamma = PNG_GAMMA_sRGB_INVERSE;
+   colorspace->flags |= PNG_COLORSPACE_HAVE_GAMMA;
+
+   /* Finally record that we have an sRGB profile */
+   colorspace->flags |=
+      (PNG_COLORSPACE_MATCHES_sRGB|PNG_COLORSPACE_FROM_sRGB);
+
+   return 1; /* set */
+}
+#endif /* sRGB */
+
+#ifdef PNG_iCCP_SUPPORTED
+/* Encoded value of D50 as an ICC XYZNumber.  From the ICC 2010 spec the value
+ * is XYZ(0.9642,1.0,0.8249), which scales to:
+ *
+ *    (63189.8112, 65536, 54060.6464)
+ */
+static const png_byte D50_nCIEXYZ[12] =
+   { 0x00, 0x00, 0xf6, 0xd6, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0xd3, 0x2d };
+
+static int /* bool */
+icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_uint_32 profile_length)
+{
+   if (profile_length < 132)
+      return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+          "too short");
+   return 1;
+}
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+int /* PRIVATE */
+png_icc_check_length(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_uint_32 profile_length)
+{
+   if (!icc_check_length(png_ptr, colorspace, name, profile_length))
+      return 0;
+
+   /* This needs to be here because the 'normal' check is in
+    * png_decompress_chunk, yet this happens after the attempt to
+    * png_malloc_base the required data.  We only need this on read; on write
+    * the caller supplies the profile buffer so libpng doesn't allocate it.  See
+    * the call to icc_check_length below (the write case).
+    */
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
+      else if (png_ptr->user_chunk_malloc_max > 0 &&
+               png_ptr->user_chunk_malloc_max < profile_length)
+         return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+             "exceeds application limits");
+#  elif PNG_USER_CHUNK_MALLOC_MAX > 0
+      else if (PNG_USER_CHUNK_MALLOC_MAX < profile_length)
+         return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+             "exceeds libpng limits");
+#  else /* !SET_USER_LIMITS */
+      /* This will get compiled out on all 32-bit and better systems. */
+      else if (PNG_SIZE_MAX < profile_length)
+         return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+             "exceeds system limits");
+#  endif /* !SET_USER_LIMITS */
+
+   return 1;
+}
+#endif /* READ_iCCP */
+
+int /* PRIVATE */
+png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_uint_32 profile_length,
+    png_const_bytep profile/* first 132 bytes only */, int color_type)
+{
+   png_uint_32 temp;
+
+   /* Length check; this cannot be ignored in this code because profile_length
+    * is used later to check the tag table, so even if the profile seems over
+    * long profile_length from the caller must be correct.  The caller can fix
+    * this up on read or write by just passing in the profile header length.
+    */
+   temp = png_get_uint_32(profile);
+   if (temp != profile_length)
+      return png_icc_profile_error(png_ptr, colorspace, name, temp,
+          "length does not match profile");
+
+   temp = (png_uint_32) (*(profile+8));
+   if (temp > 3 && (profile_length & 3))
+      return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+          "invalid length");
+
+   temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
+   if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
+      profile_length < 132+12*temp) /* truncated tag table */
+      return png_icc_profile_error(png_ptr, colorspace, name, temp,
+          "tag count too large");
+
+   /* The 'intent' must be valid or we can't store it, ICC limits the intent to
+    * 16 bits.
+    */
+   temp = png_get_uint_32(profile+64);
+   if (temp >= 0xffff) /* The ICC limit */
+      return png_icc_profile_error(png_ptr, colorspace, name, temp,
+          "invalid rendering intent");
+
+   /* This is just a warning because the profile may be valid in future
+    * versions.
+    */
+   if (temp >= PNG_sRGB_INTENT_LAST)
+      (void)png_icc_profile_error(png_ptr, NULL, name, temp,
+          "intent outside defined range");
+
+   /* At this point the tag table can't be checked because it hasn't necessarily
+    * been loaded; however, various header fields can be checked.  These checks
+    * are for values permitted by the PNG spec in an ICC profile; the PNG spec
+    * restricts the profiles that can be passed in an iCCP chunk (they must be
+    * appropriate to processing PNG data!)
+    */
+
+   /* Data checks (could be skipped).  These checks must be independent of the
+    * version number; however, the version number doesn't accomodate changes in
+    * the header fields (just the known tags and the interpretation of the
+    * data.)
+    */
+   temp = png_get_uint_32(profile+36); /* signature 'ascp' */
+   if (temp != 0x61637370)
+      return png_icc_profile_error(png_ptr, colorspace, name, temp,
+          "invalid signature");
+
+   /* Currently the PCS illuminant/adopted white point (the computational
+    * white point) are required to be D50,
+    * however the profile contains a record of the illuminant so perhaps ICC
+    * expects to be able to change this in the future (despite the rationale in
+    * the introduction for using a fixed PCS adopted white.)  Consequently the
+    * following is just a warning.
+    */
+   if (memcmp(profile+68, D50_nCIEXYZ, 12) != 0)
+      (void)png_icc_profile_error(png_ptr, NULL, name, 0/*no tag value*/,
+          "PCS illuminant is not D50");
+
+   /* The PNG spec requires this:
+    * "If the iCCP chunk is present, the image samples conform to the colour
+    * space represented by the embedded ICC profile as defined by the
+    * International Color Consortium [ICC]. The colour space of the ICC profile
+    * shall be an RGB colour space for colour images (PNG colour types 2, 3, and
+    * 6), or a greyscale colour space for greyscale images (PNG colour types 0
+    * and 4)."
+    *
+    * This checking code ensures the embedded profile (on either read or write)
+    * conforms to the specification requirements.  Notice that an ICC 'gray'
+    * color-space profile contains the information to transform the monochrome
+    * data to XYZ or L*a*b (according to which PCS the profile uses) and this
+    * should be used in preference to the standard libpng K channel replication
+    * into R, G and B channels.
+    *
+    * Previously it was suggested that an RGB profile on grayscale data could be
+    * handled.  However it it is clear that using an RGB profile in this context
+    * must be an error - there is no specification of what it means.  Thus it is
+    * almost certainly more correct to ignore the profile.
+    */
+   temp = png_get_uint_32(profile+16); /* data colour space field */
+   switch (temp)
+   {
+      case 0x52474220: /* 'RGB ' */
+         if ((color_type & PNG_COLOR_MASK_COLOR) == 0)
+            return png_icc_profile_error(png_ptr, colorspace, name, temp,
+                "RGB color space not permitted on grayscale PNG");
+         break;
+
+      case 0x47524159: /* 'GRAY' */
+         if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+            return png_icc_profile_error(png_ptr, colorspace, name, temp,
+                "Gray color space not permitted on RGB PNG");
+         break;
+
+      default:
+         return png_icc_profile_error(png_ptr, colorspace, name, temp,
+             "invalid ICC profile color space");
+   }
+
+   /* It is up to the application to check that the profile class matches the
+    * application requirements; the spec provides no guidance, but it's pretty
+    * weird if the profile is not scanner ('scnr'), monitor ('mntr'), printer
+    * ('prtr') or 'spac' (for generic color spaces).  Issue a warning in these
+    * cases.  Issue an error for device link or abstract profiles - these don't
+    * contain the records necessary to transform the color-space to anything
+    * other than the target device (and not even that for an abstract profile).
+    * Profiles of these classes may not be embedded in images.
+    */
+   temp = png_get_uint_32(profile+12); /* profile/device class */
+   switch (temp)
+   {
+      case 0x73636e72: /* 'scnr' */
+      case 0x6d6e7472: /* 'mntr' */
+      case 0x70727472: /* 'prtr' */
+      case 0x73706163: /* 'spac' */
+         /* All supported */
+         break;
+
+      case 0x61627374: /* 'abst' */
+         /* May not be embedded in an image */
+         return png_icc_profile_error(png_ptr, colorspace, name, temp,
+             "invalid embedded Abstract ICC profile");
+
+      case 0x6c696e6b: /* 'link' */
+         /* DeviceLink profiles cannot be interpreted in a non-device specific
+          * fashion, if an app uses the AToB0Tag in the profile the results are
+          * undefined unless the result is sent to the intended device,
+          * therefore a DeviceLink profile should not be found embedded in a
+          * PNG.
+          */
+         return png_icc_profile_error(png_ptr, colorspace, name, temp,
+             "unexpected DeviceLink ICC profile class");
+
+      case 0x6e6d636c: /* 'nmcl' */
+         /* A NamedColor profile is also device specific, however it doesn't
+          * contain an AToB0 tag that is open to misinterpretation.  Almost
+          * certainly it will fail the tests below.
+          */
+         (void)png_icc_profile_error(png_ptr, NULL, name, temp,
+             "unexpected NamedColor ICC profile class");
+         break;
+
+      default:
+         /* To allow for future enhancements to the profile accept unrecognized
+          * profile classes with a warning, these then hit the test below on the
+          * tag content to ensure they are backward compatible with one of the
+          * understood profiles.
+          */
+         (void)png_icc_profile_error(png_ptr, NULL, name, temp,
+             "unrecognized ICC profile class");
+         break;
+   }
+
+   /* For any profile other than a device link one the PCS must be encoded
+    * either in XYZ or Lab.
+    */
+   temp = png_get_uint_32(profile+20);
+   switch (temp)
+   {
+      case 0x58595a20: /* 'XYZ ' */
+      case 0x4c616220: /* 'Lab ' */
+         break;
+
+      default:
+         return png_icc_profile_error(png_ptr, colorspace, name, temp,
+             "unexpected ICC PCS encoding");
+   }
+
+   return 1;
+}
+
+int /* PRIVATE */
+png_icc_check_tag_table(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_uint_32 profile_length,
+    png_const_bytep profile /* header plus whole tag table */)
+{
+   png_uint_32 tag_count = png_get_uint_32(profile+128);
+   png_uint_32 itag;
+   png_const_bytep tag = profile+132; /* The first tag */
+
+   /* First scan all the tags in the table and add bits to the icc_info value
+    * (temporarily in 'tags').
+    */
+   for (itag=0; itag < tag_count; ++itag, tag += 12)
+   {
+      png_uint_32 tag_id = png_get_uint_32(tag+0);
+      png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */
+      png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */
+
+      /* The ICC specification does not exclude zero length tags, therefore the
+       * start might actually be anywhere if there is no data, but this would be
+       * a clear abuse of the intent of the standard so the start is checked for
+       * being in range.  All defined tag types have an 8 byte header - a 4 byte
+       * type signature then 0.
+       */
+
+      /* This is a hard error; potentially it can cause read outside the
+       * profile.
+       */
+      if (tag_start > profile_length || tag_length > profile_length - tag_start)
+         return png_icc_profile_error(png_ptr, colorspace, name, tag_id,
+             "ICC profile tag outside profile");
+
+      if ((tag_start & 3) != 0)
+      {
+         /* CNHP730S.icc shipped with Microsoft Windows 64 violates this; it is
+          * only a warning here because libpng does not care about the
+          * alignment.
+          */
+         (void)png_icc_profile_error(png_ptr, NULL, name, tag_id,
+             "ICC profile tag start not a multiple of 4");
+      }
+   }
+
+   return 1; /* success, maybe with warnings */
+}
+
+#ifdef PNG_sRGB_SUPPORTED
+#if PNG_sRGB_PROFILE_CHECKS >= 0
+/* Information about the known ICC sRGB profiles */
+static const struct
+{
+   png_uint_32 adler, crc, length;
+   png_uint_32 md5[4];
+   png_byte    have_md5;
+   png_byte    is_broken;
+   png_uint_16 intent;
+
+#  define PNG_MD5(a,b,c,d) { a, b, c, d }, (a!=0)||(b!=0)||(c!=0)||(d!=0)
+#  define PNG_ICC_CHECKSUM(adler, crc, md5, intent, broke, date, length, fname)\
+      { adler, crc, length, md5, broke, intent },
+
+} png_sRGB_checks[] =
+{
+   /* This data comes from contrib/tools/checksum-icc run on downloads of
+    * all four ICC sRGB profiles from www.color.org.
+    */
+   /* adler32, crc32, MD5[4], intent, date, length, file-name */
+   PNG_ICC_CHECKSUM(0x0a3fd9f6, 0x3b8772b9,
+       PNG_MD5(0x29f83dde, 0xaff255ae, 0x7842fae4, 0xca83390d), 0, 0,
+       "2009/03/27 21:36:31", 3048, "sRGB_IEC61966-2-1_black_scaled.icc")
+
+   /* ICC sRGB v2 perceptual no black-compensation: */
+   PNG_ICC_CHECKSUM(0x4909e5e1, 0x427ebb21,
+       PNG_MD5(0xc95bd637, 0xe95d8a3b, 0x0df38f99, 0xc1320389), 1, 0,
+       "2009/03/27 21:37:45", 3052, "sRGB_IEC61966-2-1_no_black_scaling.icc")
+
+   PNG_ICC_CHECKSUM(0xfd2144a1, 0x306fd8ae,
+       PNG_MD5(0xfc663378, 0x37e2886b, 0xfd72e983, 0x8228f1b8), 0, 0,
+       "2009/08/10 17:28:01", 60988, "sRGB_v4_ICC_preference_displayclass.icc")
+
+   /* ICC sRGB v4 perceptual */
+   PNG_ICC_CHECKSUM(0x209c35d2, 0xbbef7812,
+       PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, 0,
+       "2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
+
+   /* The following profiles have no known MD5 checksum. If there is a match
+    * on the (empty) MD5 the other fields are used to attempt a match and
+    * a warning is produced.  The first two of these profiles have a 'cprt' tag
+    * which suggests that they were also made by Hewlett Packard.
+    */
+   PNG_ICC_CHECKSUM(0xa054d762, 0x5d5129ce,
+       PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 0,
+       "2004/07/21 18:57:42", 3024, "sRGB_IEC61966-2-1_noBPC.icc")
+
+   /* This is a 'mntr' (display) profile with a mediaWhitePointTag that does not
+    * match the D50 PCS illuminant in the header (it is in fact the D65 values,
+    * so the white point is recorded as the un-adapted value.)  The profiles
+    * below only differ in one byte - the intent - and are basically the same as
+    * the previous profile except for the mediaWhitePointTag error and a missing
+    * chromaticAdaptationTag.
+    */
+   PNG_ICC_CHECKSUM(0xf784f3fb, 0x182ea552,
+       PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 0, 1/*broken*/,
+       "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 perceptual")
+
+   PNG_ICC_CHECKSUM(0x0398f3fc, 0xf29e526d,
+       PNG_MD5(0x00000000, 0x00000000, 0x00000000, 0x00000000), 1, 1/*broken*/,
+       "1998/02/09 06:49:00", 3144, "HP-Microsoft sRGB v2 media-relative")
+};
+
+static int
+png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
+    png_const_bytep profile, uLong adler)
+{
+   /* The quick check is to verify just the MD5 signature and trust the
+    * rest of the data.  Because the profile has already been verified for
+    * correctness this is safe.  png_colorspace_set_sRGB will check the 'intent'
+    * field too, so if the profile has been edited with an intent not defined
+    * by sRGB (but maybe defined by a later ICC specification) the read of
+    * the profile will fail at that point.
+    */
+
+   png_uint_32 length = 0;
+   png_uint_32 intent = 0x10000; /* invalid */
+#if PNG_sRGB_PROFILE_CHECKS > 1
+   uLong crc = 0; /* the value for 0 length data */
+#endif
+   unsigned int i;
+
+#ifdef PNG_SET_OPTION_SUPPORTED
+   /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */
+   if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) ==
+               PNG_OPTION_ON)
+      return 0;
+#endif
+
+   for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i)
+   {
+      if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] &&
+         png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] &&
+         png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] &&
+         png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3])
+      {
+         /* This may be one of the old HP profiles without an MD5, in that
+          * case we can only use the length and Adler32 (note that these
+          * are not used by default if there is an MD5!)
+          */
+#        if PNG_sRGB_PROFILE_CHECKS == 0
+            if (png_sRGB_checks[i].have_md5 != 0)
+               return 1+png_sRGB_checks[i].is_broken;
+#        endif
+
+         /* Profile is unsigned or more checks have been configured in. */
+         if (length == 0)
+         {
+            length = png_get_uint_32(profile);
+            intent = png_get_uint_32(profile+64);
+         }
+
+         /* Length *and* intent must match */
+         if (length == (png_uint_32) png_sRGB_checks[i].length &&
+            intent == (png_uint_32) png_sRGB_checks[i].intent)
+         {
+            /* Now calculate the adler32 if not done already. */
+            if (adler == 0)
+            {
+               adler = adler32(0, NULL, 0);
+               adler = adler32(adler, profile, length);
+            }
+
+            if (adler == png_sRGB_checks[i].adler)
+            {
+               /* These basic checks suggest that the data has not been
+                * modified, but if the check level is more than 1 perform
+                * our own crc32 checksum on the data.
+                */
+#              if PNG_sRGB_PROFILE_CHECKS > 1
+                  if (crc == 0)
+                  {
+                     crc = crc32(0, NULL, 0);
+                     crc = crc32(crc, profile, length);
+                  }
+
+                  /* So this check must pass for the 'return' below to happen.
+                   */
+                  if (crc == png_sRGB_checks[i].crc)
+#              endif
+               {
+                  if (png_sRGB_checks[i].is_broken != 0)
+                  {
+                     /* These profiles are known to have bad data that may cause
+                      * problems if they are used, therefore attempt to
+                      * discourage their use, skip the 'have_md5' warning below,
+                      * which is made irrelevant by this error.
+                      */
+                     png_chunk_report(png_ptr, "known incorrect sRGB profile",
+                         PNG_CHUNK_ERROR);
+                  }
+
+                  /* Warn that this being done; this isn't even an error since
+                   * the profile is perfectly valid, but it would be nice if
+                   * people used the up-to-date ones.
+                   */
+                  else if (png_sRGB_checks[i].have_md5 == 0)
+                  {
+                     png_chunk_report(png_ptr,
+                         "out-of-date sRGB profile with no signature",
+                         PNG_CHUNK_WARNING);
+                  }
+
+                  return 1+png_sRGB_checks[i].is_broken;
+               }
+            }
+
+# if PNG_sRGB_PROFILE_CHECKS > 0
+         /* The signature matched, but the profile had been changed in some
+          * way.  This probably indicates a data error or uninformed hacking.
+          * Fall through to "no match".
+          */
+         png_chunk_report(png_ptr,
+             "Not recognizing known sRGB profile that has been edited",
+             PNG_CHUNK_WARNING);
+         break;
+# endif
+         }
+      }
+   }
+
+   return 0; /* no match */
+}
+
+void /* PRIVATE */
+png_icc_set_sRGB(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, png_const_bytep profile, uLong adler)
+{
+   /* Is this profile one of the known ICC sRGB profiles?  If it is, just set
+    * the sRGB information.
+    */
+   if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0)
+      (void)png_colorspace_set_sRGB(png_ptr, colorspace,
+         (int)/*already checked*/png_get_uint_32(profile+64));
+}
+#endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
+#endif /* sRGB */
+
+int /* PRIVATE */
+png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
+    png_const_charp name, png_uint_32 profile_length, png_const_bytep profile,
+    int color_type)
+{
+   if ((colorspace->flags & PNG_COLORSPACE_INVALID) != 0)
+      return 0;
+
+   if (icc_check_length(png_ptr, colorspace, name, profile_length) != 0 &&
+       png_icc_check_header(png_ptr, colorspace, name, profile_length, profile,
+           color_type) != 0 &&
+       png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,
+           profile) != 0)
+   {
+#     if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
+         /* If no sRGB support, don't try storing sRGB information */
+         png_icc_set_sRGB(png_ptr, colorspace, profile, 0);
+#     endif
+      return 1;
+   }
+
+   /* Failure case */
+   return 0;
+}
+#endif /* iCCP */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+void /* PRIVATE */
+png_colorspace_set_rgb_coefficients(png_structrp png_ptr)
+{
+   /* Set the rgb_to_gray coefficients from the colorspace. */
+   if (png_ptr->rgb_to_gray_coefficients_set == 0 &&
+      (png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      /* png_set_background has not been called, get the coefficients from the Y
+       * values of the colorspace colorants.
+       */
+      png_fixed_point r = png_ptr->colorspace.end_points_XYZ.red_Y;
+      png_fixed_point g = png_ptr->colorspace.end_points_XYZ.green_Y;
+      png_fixed_point b = png_ptr->colorspace.end_points_XYZ.blue_Y;
+      png_fixed_point total = r+g+b;
+
+      if (total > 0 &&
+         r >= 0 && png_muldiv(&r, r, 32768, total) && r >= 0 && r <= 32768 &&
+         g >= 0 && png_muldiv(&g, g, 32768, total) && g >= 0 && g <= 32768 &&
+         b >= 0 && png_muldiv(&b, b, 32768, total) && b >= 0 && b <= 32768 &&
+         r+g+b <= 32769)
+      {
+         /* We allow 0 coefficients here.  r+g+b may be 32769 if two or
+          * all of the coefficients were rounded up.  Handle this by
+          * reducing the *largest* coefficient by 1; this matches the
+          * approach used for the default coefficients in pngrtran.c
+          */
+         int add = 0;
+
+         if (r+g+b > 32768)
+            add = -1;
+         else if (r+g+b < 32768)
+            add = 1;
+
+         if (add != 0)
+         {
+            if (g >= r && g >= b)
+               g += add;
+            else if (r >= g && r >= b)
+               r += add;
+            else
+               b += add;
+         }
+
+         /* Check for an internal error. */
+         if (r+g+b != 32768)
+            png_error(png_ptr,
+                "internal error handling cHRM coefficients");
+
+         else
+         {
+            png_ptr->rgb_to_gray_red_coeff   = (png_uint_16)r;
+            png_ptr->rgb_to_gray_green_coeff = (png_uint_16)g;
+         }
+      }
+
+      /* This is a png_error at present even though it could be ignored -
+       * it should never happen, but it is important that if it does, the
+       * bug is fixed.
+       */
+      else
+         png_error(png_ptr, "internal error handling cHRM->XYZ");
+   }
+}
+#endif /* READ_RGB_TO_GRAY */
+
+#endif /* COLORSPACE */
+
+#ifdef __GNUC__
+/* This exists solely to work round a warning from GNU C. */
+static int /* PRIVATE */
+png_gt(size_t a, size_t b)
+{
+   return a > b;
+}
+#else
+#   define png_gt(a,b) ((a) > (b))
+#endif
+
+void /* PRIVATE */
+png_check_IHDR(png_const_structrp png_ptr,
+    png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_type, int compression_type,
+    int filter_type)
+{
+   int error = 0;
+
+   /* Check for width and height valid values */
+   if (width == 0)
+   {
+      png_warning(png_ptr, "Image width is zero in IHDR");
+      error = 1;
+   }
+
+   if (width > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image width in IHDR");
+      error = 1;
+   }
+
+   if (png_gt(((width + 7) & (~7U)),
+       ((PNG_SIZE_MAX
+           - 48        /* big_row_buf hack */
+           - 1)        /* filter byte */
+           / 8)        /* 8-byte RGBA pixels */
+           - 1))       /* extra max_pixel_depth pad */
+   {
+      /* The size of the row must be within the limits of this architecture.
+       * Because the read code can perform arbitrary transformations the
+       * maximum size is checked here.  Because the code in png_read_start_row
+       * adds extra space "for safety's sake" in several places a conservative
+       * limit is used here.
+       *
+       * NOTE: it would be far better to check the size that is actually used,
+       * but the effect in the real world is minor and the changes are more
+       * extensive, therefore much more dangerous and much more difficult to
+       * write in a way that avoids compiler warnings.
+       */
+      png_warning(png_ptr, "Image width is too large for this architecture");
+      error = 1;
+   }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (width > png_ptr->user_width_max)
+#else
+   if (width > PNG_USER_WIDTH_MAX)
+#endif
+   {
+      png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+      error = 1;
+   }
+
+   if (height == 0)
+   {
+      png_warning(png_ptr, "Image height is zero in IHDR");
+      error = 1;
+   }
+
+   if (height > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image height in IHDR");
+      error = 1;
+   }
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (height > png_ptr->user_height_max)
+#else
+   if (height > PNG_USER_HEIGHT_MAX)
+#endif
+   {
+      png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+      error = 1;
+   }
+
+   /* Check other values */
+   if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
+       bit_depth != 8 && bit_depth != 16)
+   {
+      png_warning(png_ptr, "Invalid bit depth in IHDR");
+      error = 1;
+   }
+
+   if (color_type < 0 || color_type == 1 ||
+       color_type == 5 || color_type > 6)
+   {
+      png_warning(png_ptr, "Invalid color type in IHDR");
+      error = 1;
+   }
+
+   if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
+       ((color_type == PNG_COLOR_TYPE_RGB ||
+         color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
+         color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
+   {
+      png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
+      error = 1;
+   }
+
+   if (interlace_type >= PNG_INTERLACE_LAST)
+   {
+      png_warning(png_ptr, "Unknown interlace method in IHDR");
+      error = 1;
+   }
+
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Unknown compression method in IHDR");
+      error = 1;
+   }
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   /* Accept filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not read a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 &&
+       png_ptr->mng_features_permitted != 0)
+      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+
+   if (filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+          (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
+          ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+          (color_type == PNG_COLOR_TYPE_RGB ||
+          color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+      {
+         png_warning(png_ptr, "Unknown filter method in IHDR");
+         error = 1;
+      }
+
+      if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0)
+      {
+         png_warning(png_ptr, "Invalid filter method in IHDR");
+         error = 1;
+      }
+   }
+
+#else
+   if (filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Unknown filter method in IHDR");
+      error = 1;
+   }
+#endif
+
+   if (error == 1)
+      png_error(png_ptr, "Invalid IHDR data");
+}
+
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* ASCII to fp functions */
+/* Check an ASCII formated floating point value, see the more detailed
+ * comments in pngpriv.h
+ */
+/* The following is used internally to preserve the sticky flags */
+#define png_fp_add(state, flags) ((state) |= (flags))
+#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
+
+int /* PRIVATE */
+png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
+    png_size_tp whereami)
+{
+   int state = *statep;
+   png_size_t i = *whereami;
+
+   while (i < size)
+   {
+      int type;
+      /* First find the type of the next character */
+      switch (string[i])
+      {
+      case 43:  type = PNG_FP_SAW_SIGN;                   break;
+      case 45:  type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break;
+      case 46:  type = PNG_FP_SAW_DOT;                    break;
+      case 48:  type = PNG_FP_SAW_DIGIT;                  break;
+      case 49: case 50: case 51: case 52:
+      case 53: case 54: case 55: case 56:
+      case 57:  type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
+      case 69:
+      case 101: type = PNG_FP_SAW_E;                      break;
+      default:  goto PNG_FP_End;
+      }
+
+      /* Now deal with this type according to the current
+       * state, the type is arranged to not overlap the
+       * bits of the PNG_FP_STATE.
+       */
+      switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY))
+      {
+      case PNG_FP_INTEGER + PNG_FP_SAW_SIGN:
+         if ((state & PNG_FP_SAW_ANY) != 0)
+            goto PNG_FP_End; /* not a part of the number */
+
+         png_fp_add(state, type);
+         break;
+
+      case PNG_FP_INTEGER + PNG_FP_SAW_DOT:
+         /* Ok as trailer, ok as lead of fraction. */
+         if ((state & PNG_FP_SAW_DOT) != 0) /* two dots */
+            goto PNG_FP_End;
+
+         else if ((state & PNG_FP_SAW_DIGIT) != 0) /* trailing dot? */
+            png_fp_add(state, type);
+
+         else
+            png_fp_set(state, PNG_FP_FRACTION | type);
+
+         break;
+
+      case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT:
+         if ((state & PNG_FP_SAW_DOT) != 0) /* delayed fraction */
+            png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
+
+         png_fp_add(state, type | PNG_FP_WAS_VALID);
+
+         break;
+
+      case PNG_FP_INTEGER + PNG_FP_SAW_E:
+         if ((state & PNG_FP_SAW_DIGIT) == 0)
+            goto PNG_FP_End;
+
+         png_fp_set(state, PNG_FP_EXPONENT);
+
+         break;
+
+   /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN:
+         goto PNG_FP_End; ** no sign in fraction */
+
+   /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT:
+         goto PNG_FP_End; ** Because SAW_DOT is always set */
+
+      case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT:
+         png_fp_add(state, type | PNG_FP_WAS_VALID);
+         break;
+
+      case PNG_FP_FRACTION + PNG_FP_SAW_E:
+         /* This is correct because the trailing '.' on an
+          * integer is handled above - so we can only get here
+          * with the sequence ".E" (with no preceding digits).
+          */
+         if ((state & PNG_FP_SAW_DIGIT) == 0)
+            goto PNG_FP_End;
+
+         png_fp_set(state, PNG_FP_EXPONENT);
+
+         break;
+
+      case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN:
+         if ((state & PNG_FP_SAW_ANY) != 0)
+            goto PNG_FP_End; /* not a part of the number */
+
+         png_fp_add(state, PNG_FP_SAW_SIGN);
+
+         break;
+
+   /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT:
+         goto PNG_FP_End; */
+
+      case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT:
+         png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID);
+
+         break;
+
+   /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E:
+         goto PNG_FP_End; */
+
+      default: goto PNG_FP_End; /* I.e. break 2 */
+      }
+
+      /* The character seems ok, continue. */
+      ++i;
+   }
+
+PNG_FP_End:
+   /* Here at the end, update the state and return the correct
+    * return code.
+    */
+   *statep = state;
+   *whereami = i;
+
+   return (state & PNG_FP_SAW_DIGIT) != 0;
+}
+
+
+/* The same but for a complete string. */
+int
+png_check_fp_string(png_const_charp string, png_size_t size)
+{
+   int        state=0;
+   png_size_t char_index=0;
+
+   if (png_check_fp_number(string, size, &state, &char_index) != 0 &&
+      (char_index == size || string[char_index] == 0))
+      return state /* must be non-zero - see above */;
+
+   return 0; /* i.e. fail */
+}
+#endif /* pCAL || sCAL */
+
+#ifdef PNG_sCAL_SUPPORTED
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Utility used below - a simple accurate power of ten from an integral
+ * exponent.
+ */
+static double
+png_pow10(int power)
+{
+   int recip = 0;
+   double d = 1;
+
+   /* Handle negative exponent with a reciprocal at the end because
+    * 10 is exact whereas .1 is inexact in base 2
+    */
+   if (power < 0)
+   {
+      if (power < DBL_MIN_10_EXP) return 0;
+      recip = 1; power = -power;
+   }
+
+   if (power > 0)
+   {
+      /* Decompose power bitwise. */
+      double mult = 10;
+      do
+      {
+         if (power & 1) d *= mult;
+         mult *= mult;
+         power >>= 1;
+      }
+      while (power > 0);
+
+      if (recip != 0) d = 1/d;
+   }
+   /* else power is 0 and d is 1 */
+
+   return d;
+}
+
+/* Function to format a floating point value in ASCII with a given
+ * precision.
+ */
+#if GCC_STRICT_OVERFLOW
+#pragma GCC diagnostic push
+/* The problem arises below with exp_b10, which can never overflow because it
+ * comes, originally, from frexp and is therefore limited to a range which is
+ * typically +/-710 (log2(DBL_MAX)/log2(DBL_MIN)).
+ */
+#pragma GCC diagnostic warning "-Wstrict-overflow=2"
+#endif /* GCC_STRICT_OVERFLOW */
+void /* PRIVATE */
+png_ascii_from_fp(png_const_structrp png_ptr, png_charp ascii, png_size_t size,
+    double fp, unsigned int precision)
+{
+   /* We use standard functions from math.h, but not printf because
+    * that would require stdio.  The caller must supply a buffer of
+    * sufficient size or we will png_error.  The tests on size and
+    * the space in ascii[] consumed are indicated below.
+    */
+   if (precision < 1)
+      precision = DBL_DIG;
+
+   /* Enforce the limit of the implementation precision too. */
+   if (precision > DBL_DIG+1)
+      precision = DBL_DIG+1;
+
+   /* Basic sanity checks */
+   if (size >= precision+5) /* See the requirements below. */
+   {
+      if (fp < 0)
+      {
+         fp = -fp;
+         *ascii++ = 45; /* '-'  PLUS 1 TOTAL 1 */
+         --size;
+      }
+
+      if (fp >= DBL_MIN && fp <= DBL_MAX)
+      {
+         int exp_b10;   /* A base 10 exponent */
+         double base;   /* 10^exp_b10 */
+
+         /* First extract a base 10 exponent of the number,
+          * the calculation below rounds down when converting
+          * from base 2 to base 10 (multiply by log10(2) -
+          * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to
+          * be increased.  Note that the arithmetic shift
+          * performs a floor() unlike C arithmetic - using a
+          * C multiply would break the following for negative
+          * exponents.
+          */
+         (void)frexp(fp, &exp_b10); /* exponent to base 2 */
+
+         exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */
+
+         /* Avoid underflow here. */
+         base = png_pow10(exp_b10); /* May underflow */
+
+         while (base < DBL_MIN || base < fp)
+         {
+            /* And this may overflow. */
+            double test = png_pow10(exp_b10+1);
+
+            if (test <= DBL_MAX)
+            {
+               ++exp_b10; base = test;
+            }
+
+            else
+               break;
+         }
+
+         /* Normalize fp and correct exp_b10, after this fp is in the
+          * range [.1,1) and exp_b10 is both the exponent and the digit
+          * *before* which the decimal point should be inserted
+          * (starting with 0 for the first digit).  Note that this
+          * works even if 10^exp_b10 is out of range because of the
+          * test on DBL_MAX above.
+          */
+         fp /= base;
+         while (fp >= 1)
+         {
+            fp /= 10; ++exp_b10;
+         }
+
+         /* Because of the code above fp may, at this point, be
+          * less than .1, this is ok because the code below can
+          * handle the leading zeros this generates, so no attempt
+          * is made to correct that here.
+          */
+
+         {
+            unsigned int czero, clead, cdigits;
+            char exponent[10];
+
+            /* Allow up to two leading zeros - this will not lengthen
+             * the number compared to using E-n.
+             */
+            if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */
+            {
+               czero = 0U-exp_b10; /* PLUS 2 digits: TOTAL 3 */
+               exp_b10 = 0;      /* Dot added below before first output. */
+            }
+            else
+               czero = 0;    /* No zeros to add */
+
+            /* Generate the digit list, stripping trailing zeros and
+             * inserting a '.' before a digit if the exponent is 0.
+             */
+            clead = czero; /* Count of leading zeros */
+            cdigits = 0;   /* Count of digits in list. */
+
+            do
+            {
+               double d;
+
+               fp *= 10;
+               /* Use modf here, not floor and subtract, so that
+                * the separation is done in one step.  At the end
+                * of the loop don't break the number into parts so
+                * that the final digit is rounded.
+                */
+               if (cdigits+czero+1 < precision+clead)
+                  fp = modf(fp, &d);
+
+               else
+               {
+                  d = floor(fp + .5);
+
+                  if (d > 9)
+                  {
+                     /* Rounding up to 10, handle that here. */
+                     if (czero > 0)
+                     {
+                        --czero; d = 1;
+                        if (cdigits == 0) --clead;
+                     }
+                     else
+                     {
+                        while (cdigits > 0 && d > 9)
+                        {
+                           int ch = *--ascii;
+
+                           if (exp_b10 != (-1))
+                              ++exp_b10;
+
+                           else if (ch == 46)
+                           {
+                              ch = *--ascii; ++size;
+                              /* Advance exp_b10 to '1', so that the
+                               * decimal point happens after the
+                               * previous digit.
+                               */
+                              exp_b10 = 1;
+                           }
+
+                           --cdigits;
+                           d = ch - 47;  /* I.e. 1+(ch-48) */
+                        }
+
+                        /* Did we reach the beginning? If so adjust the
+                         * exponent but take into account the leading
+                         * decimal point.
+                         */
+                        if (d > 9)  /* cdigits == 0 */
+                        {
+                           if (exp_b10 == (-1))
+                           {
+                              /* Leading decimal point (plus zeros?), if
+                               * we lose the decimal point here it must
+                               * be reentered below.
+                               */
+                              int ch = *--ascii;
+
+                              if (ch == 46)
+                              {
+                                 ++size; exp_b10 = 1;
+                              }
+
+                              /* Else lost a leading zero, so 'exp_b10' is
+                               * still ok at (-1)
+                               */
+                           }
+                           else
+                              ++exp_b10;
+
+                           /* In all cases we output a '1' */
+                           d = 1;
+                        }
+                     }
+                  }
+                  fp = 0; /* Guarantees termination below. */
+               }
+
+               if (d == 0)
+               {
+                  ++czero;
+                  if (cdigits == 0) ++clead;
+               }
+               else
+               {
+                  /* Included embedded zeros in the digit count. */
+                  cdigits += czero - clead;
+                  clead = 0;
+
+                  while (czero > 0)
+                  {
+                     /* exp_b10 == (-1) means we just output the decimal
+                      * place - after the DP don't adjust 'exp_b10' any
+                      * more!
+                      */
+                     if (exp_b10 != (-1))
+                     {
+                        if (exp_b10 == 0)
+                        {
+                           *ascii++ = 46; --size;
+                        }
+                        /* PLUS 1: TOTAL 4 */
+                        --exp_b10;
+                     }
+                     *ascii++ = 48; --czero;
+                  }
+
+                  if (exp_b10 != (-1))
+                  {
+                     if (exp_b10 == 0)
+                     {
+                        *ascii++ = 46; --size; /* counted above */
+                     }
+
+                     --exp_b10;
+                  }
+                  *ascii++ = (char)(48 + (int)d); ++cdigits;
+               }
+            }
+            while (cdigits+czero < precision+clead && fp > DBL_MIN);
+
+            /* The total output count (max) is now 4+precision */
+
+            /* Check for an exponent, if we don't need one we are
+             * done and just need to terminate the string.  At
+             * this point exp_b10==(-1) is effectively a flag - it got
+             * to '-1' because of the decrement after outputting
+             * the decimal point above (the exponent required is
+             * *not* -1!)
+             */
+            if (exp_b10 >= (-1) && exp_b10 <= 2)
+            {
+               /* The following only happens if we didn't output the
+                * leading zeros above for negative exponent, so this
+                * doesn't add to the digit requirement.  Note that the
+                * two zeros here can only be output if the two leading
+                * zeros were *not* output, so this doesn't increase
+                * the output count.
+                */
+               while (exp_b10-- > 0) *ascii++ = 48;
+
+               *ascii = 0;
+
+               /* Total buffer requirement (including the '\0') is
+                * 5+precision - see check at the start.
+                */
+               return;
+            }
+
+            /* Here if an exponent is required, adjust size for
+             * the digits we output but did not count.  The total
+             * digit output here so far is at most 1+precision - no
+             * decimal point and no leading or trailing zeros have
+             * been output.
+             */
+            size -= cdigits;
+
+            *ascii++ = 69; --size;    /* 'E': PLUS 1 TOTAL 2+precision */
+
+            /* The following use of an unsigned temporary avoids ambiguities in
+             * the signed arithmetic on exp_b10 and permits GCC at least to do
+             * better optimization.
+             */
+            {
+               unsigned int uexp_b10;
+
+               if (exp_b10 < 0)
+               {
+                  *ascii++ = 45; --size; /* '-': PLUS 1 TOTAL 3+precision */
+                  uexp_b10 = 0U-exp_b10;
+               }
+
+               else
+                  uexp_b10 = 0U+exp_b10;
+
+               cdigits = 0;
+
+               while (uexp_b10 > 0)
+               {
+                  exponent[cdigits++] = (char)(48 + uexp_b10 % 10);
+                  uexp_b10 /= 10;
+               }
+            }
+
+            /* Need another size check here for the exponent digits, so
+             * this need not be considered above.
+             */
+            if (size > cdigits)
+            {
+               while (cdigits > 0) *ascii++ = exponent[--cdigits];
+
+               *ascii = 0;
+
+               return;
+            }
+         }
+      }
+      else if (!(fp >= DBL_MIN))
+      {
+         *ascii++ = 48; /* '0' */
+         *ascii = 0;
+         return;
+      }
+      else
+      {
+         *ascii++ = 105; /* 'i' */
+         *ascii++ = 110; /* 'n' */
+         *ascii++ = 102; /* 'f' */
+         *ascii = 0;
+         return;
+      }
+   }
+
+   /* Here on buffer too small. */
+   png_error(png_ptr, "ASCII conversion buffer too small");
+}
+#if GCC_STRICT_OVERFLOW
+#pragma GCC diagnostic pop
+#endif /* GCC_STRICT_OVERFLOW */
+
+#  endif /* FLOATING_POINT */
+
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+/* Function to format a fixed point value in ASCII.
+ */
+void /* PRIVATE */
+png_ascii_from_fixed(png_const_structrp png_ptr, png_charp ascii,
+    png_size_t size, png_fixed_point fp)
+{
+   /* Require space for 10 decimal digits, a decimal point, a minus sign and a
+    * trailing \0, 13 characters:
+    */
+   if (size > 12)
+   {
+      png_uint_32 num;
+
+      /* Avoid overflow here on the minimum integer. */
+      if (fp < 0)
+      {
+         *ascii++ = 45; num = (png_uint_32)(-fp);
+      }
+      else
+         num = (png_uint_32)fp;
+
+      if (num <= 0x80000000) /* else overflowed */
+      {
+         unsigned int ndigits = 0, first = 16 /* flag value */;
+         char digits[10];
+
+         while (num)
+         {
+            /* Split the low digit off num: */
+            unsigned int tmp = num/10;
+            num -= tmp*10;
+            digits[ndigits++] = (char)(48 + num);
+            /* Record the first non-zero digit, note that this is a number
+             * starting at 1, it's not actually the array index.
+             */
+            if (first == 16 && num > 0)
+               first = ndigits;
+            num = tmp;
+         }
+
+         if (ndigits > 0)
+         {
+            while (ndigits > 5) *ascii++ = digits[--ndigits];
+            /* The remaining digits are fractional digits, ndigits is '5' or
+             * smaller at this point.  It is certainly not zero.  Check for a
+             * non-zero fractional digit:
+             */
+            if (first <= 5)
+            {
+               unsigned int i;
+               *ascii++ = 46; /* decimal point */
+               /* ndigits may be <5 for small numbers, output leading zeros
+                * then ndigits digits to first:
+                */
+               i = 5;
+               while (ndigits < i)
+               {
+                  *ascii++ = 48; --i;
+               }
+               while (ndigits >= first) *ascii++ = digits[--ndigits];
+               /* Don't output the trailing zeros! */
+            }
+         }
+         else
+            *ascii++ = 48;
+
+         /* And null terminate the string: */
+         *ascii = 0;
+         return;
+      }
+   }
+
+   /* Here on buffer too small. */
+   png_error(png_ptr, "ASCII conversion buffer too small");
+}
+#   endif /* FIXED_POINT */
+#endif /* SCAL */
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+   (defined(PNG_sCAL_SUPPORTED) && \
+   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
+png_fixed_point
+png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text)
+{
+   double r = floor(100000 * fp + .5);
+
+   if (r > 2147483647. || r < -2147483648.)
+      png_fixed_error(png_ptr, text);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+   PNG_UNUSED(text)
+#  endif
+
+   return (png_fixed_point)r;
+}
+#endif
+
+#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\
+    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
+/* muldiv functions */
+/* This API takes signed arguments and rounds the result to the nearest
+ * integer (or, for a fixed point number - the standard argument - to
+ * the nearest .00001).  Overflow and divide by zero are signalled in
+ * the result, a boolean - true on success, false on overflow.
+ */
+#if GCC_STRICT_OVERFLOW /* from above */
+/* It is not obvious which comparison below gets optimized in such a way that
+ * signed overflow would change the result; looking through the code does not
+ * reveal any tests which have the form GCC complains about, so presumably the
+ * optimizer is moving an add or subtract into the 'if' somewhere.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic warning "-Wstrict-overflow=2"
+#endif /* GCC_STRICT_OVERFLOW */
+int
+png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
+    png_int_32 divisor)
+{
+   /* Return a * times / divisor, rounded. */
+   if (divisor != 0)
+   {
+      if (a == 0 || times == 0)
+      {
+         *res = 0;
+         return 1;
+      }
+      else
+      {
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+         double r = a;
+         r *= times;
+         r /= divisor;
+         r = floor(r+.5);
+
+         /* A png_fixed_point is a 32-bit integer. */
+         if (r <= 2147483647. && r >= -2147483648.)
+         {
+            *res = (png_fixed_point)r;
+            return 1;
+         }
+#else
+         int negative = 0;
+         png_uint_32 A, T, D;
+         png_uint_32 s16, s32, s00;
+
+         if (a < 0)
+            negative = 1, A = -a;
+         else
+            A = a;
+
+         if (times < 0)
+            negative = !negative, T = -times;
+         else
+            T = times;
+
+         if (divisor < 0)
+            negative = !negative, D = -divisor;
+         else
+            D = divisor;
+
+         /* Following can't overflow because the arguments only
+          * have 31 bits each, however the result may be 32 bits.
+          */
+         s16 = (A >> 16) * (T & 0xffff) +
+                           (A & 0xffff) * (T >> 16);
+         /* Can't overflow because the a*times bit is only 30
+          * bits at most.
+          */
+         s32 = (A >> 16) * (T >> 16) + (s16 >> 16);
+         s00 = (A & 0xffff) * (T & 0xffff);
+
+         s16 = (s16 & 0xffff) << 16;
+         s00 += s16;
+
+         if (s00 < s16)
+            ++s32; /* carry */
+
+         if (s32 < D) /* else overflow */
+         {
+            /* s32.s00 is now the 64-bit product, do a standard
+             * division, we know that s32 < D, so the maximum
+             * required shift is 31.
+             */
+            int bitshift = 32;
+            png_fixed_point result = 0; /* NOTE: signed */
+
+            while (--bitshift >= 0)
+            {
+               png_uint_32 d32, d00;
+
+               if (bitshift > 0)
+                  d32 = D >> (32-bitshift), d00 = D << bitshift;
+
+               else
+                  d32 = 0, d00 = D;
+
+               if (s32 > d32)
+               {
+                  if (s00 < d00) --s32; /* carry */
+                  s32 -= d32, s00 -= d00, result += 1<<bitshift;
+               }
+
+               else
+                  if (s32 == d32 && s00 >= d00)
+                     s32 = 0, s00 -= d00, result += 1<<bitshift;
+            }
+
+            /* Handle the rounding. */
+            if (s00 >= (D >> 1))
+               ++result;
+
+            if (negative != 0)
+               result = -result;
+
+            /* Check for overflow. */
+            if ((negative != 0 && result <= 0) ||
+                (negative == 0 && result >= 0))
+            {
+               *res = result;
+               return 1;
+            }
+         }
+#endif
+      }
+   }
+
+   return 0;
+}
+#if GCC_STRICT_OVERFLOW
+#pragma GCC diagnostic pop
+#endif /* GCC_STRICT_OVERFLOW */
+#endif /* READ_GAMMA || INCH_CONVERSIONS */
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+/* The following is for when the caller doesn't much care about the
+ * result.
+ */
+png_fixed_point
+png_muldiv_warn(png_const_structrp png_ptr, png_fixed_point a, png_int_32 times,
+    png_int_32 divisor)
+{
+   png_fixed_point result;
+
+   if (png_muldiv(&result, a, times, divisor) != 0)
+      return result;
+
+   png_warning(png_ptr, "fixed point overflow ignored");
+   return 0;
+}
+#endif
+
+#ifdef PNG_GAMMA_SUPPORTED /* more fixed point functions for gamma */
+/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */
+png_fixed_point
+png_reciprocal(png_fixed_point a)
+{
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   double r = floor(1E10/a+.5);
+
+   if (r <= 2147483647. && r >= -2147483648.)
+      return (png_fixed_point)r;
+#else
+   png_fixed_point res;
+
+   if (png_muldiv(&res, 100000, 100000, a) != 0)
+      return res;
+#endif
+
+   return 0; /* error/overflow */
+}
+
+/* This is the shared test on whether a gamma value is 'significant' - whether
+ * it is worth doing gamma correction.
+ */
+int /* PRIVATE */
+png_gamma_significant(png_fixed_point gamma_val)
+{
+   return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED ||
+       gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED;
+}
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+#ifdef PNG_16BIT_SUPPORTED
+/* A local convenience routine. */
+static png_fixed_point
+png_product2(png_fixed_point a, png_fixed_point b)
+{
+   /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   double r = a * 1E-5;
+   r *= b;
+   r = floor(r+.5);
+
+   if (r <= 2147483647. && r >= -2147483648.)
+      return (png_fixed_point)r;
+#else
+   png_fixed_point res;
+
+   if (png_muldiv(&res, a, b, 100000) != 0)
+      return res;
+#endif
+
+   return 0; /* overflow */
+}
+#endif /* 16BIT */
+
+/* The inverse of the above. */
+png_fixed_point
+png_reciprocal2(png_fixed_point a, png_fixed_point b)
+{
+   /* The required result is 1/a * 1/b; the following preserves accuracy. */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   if (a != 0 && b != 0)
+   {
+      double r = 1E15/a;
+      r /= b;
+      r = floor(r+.5);
+
+      if (r <= 2147483647. && r >= -2147483648.)
+         return (png_fixed_point)r;
+   }
+#else
+   /* This may overflow because the range of png_fixed_point isn't symmetric,
+    * but this API is only used for the product of file and screen gamma so it
+    * doesn't matter that the smallest number it can produce is 1/21474, not
+    * 1/100000
+    */
+   png_fixed_point res = png_product2(a, b);
+
+   if (res != 0)
+      return png_reciprocal(res);
+#endif
+
+   return 0; /* overflow */
+}
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */
+#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED
+/* Fixed point gamma.
+ *
+ * The code to calculate the tables used below can be found in the shell script
+ * contrib/tools/intgamma.sh
+ *
+ * To calculate gamma this code implements fast log() and exp() calls using only
+ * fixed point arithmetic.  This code has sufficient precision for either 8-bit
+ * or 16-bit sample values.
+ *
+ * The tables used here were calculated using simple 'bc' programs, but C double
+ * precision floating point arithmetic would work fine.
+ *
+ * 8-bit log table
+ *   This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
+ *   255, so it's the base 2 logarithm of a normalized 8-bit floating point
+ *   mantissa.  The numbers are 32-bit fractions.
+ */
+static const png_uint_32
+png_8bit_l2[128] =
+{
+   4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U,
+   3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U,
+   3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U,
+   3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U,
+   3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U,
+   2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U,
+   2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U,
+   2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U,
+   2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U,
+   2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U,
+   1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U,
+   1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U,
+   1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U,
+   1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U,
+   1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U,
+   971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U,
+   803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U,
+   639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U,
+   479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U,
+   324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U,
+   172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U,
+   24347096U, 0U
+
+#if 0
+   /* The following are the values for 16-bit tables - these work fine for the
+    * 8-bit conversions but produce very slightly larger errors in the 16-bit
+    * log (about 1.2 as opposed to 0.7 absolute error in the final value).  To
+    * use these all the shifts below must be adjusted appropriately.
+    */
+   65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054,
+   57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803,
+   50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068,
+   43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782,
+   37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887,
+   31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339,
+   25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098,
+   20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132,
+   15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415,
+   10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523,
+   6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495,
+   1119, 744, 372
+#endif
+};
+
+static png_int_32
+png_log8bit(unsigned int x)
+{
+   unsigned int lg2 = 0;
+   /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log,
+    * because the log is actually negate that means adding 1.  The final
+    * returned value thus has the range 0 (for 255 input) to 7.994 (for 1
+    * input), return -1 for the overflow (log 0) case, - so the result is
+    * always at most 19 bits.
+    */
+   if ((x &= 0xff) == 0)
+      return -1;
+
+   if ((x & 0xf0) == 0)
+      lg2  = 4, x <<= 4;
+
+   if ((x & 0xc0) == 0)
+      lg2 += 2, x <<= 2;
+
+   if ((x & 0x80) == 0)
+      lg2 += 1, x <<= 1;
+
+   /* result is at most 19 bits, so this cast is safe: */
+   return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16));
+}
+
+/* The above gives exact (to 16 binary places) log2 values for 8-bit images,
+ * for 16-bit images we use the most significant 8 bits of the 16-bit value to
+ * get an approximation then multiply the approximation by a correction factor
+ * determined by the remaining up to 8 bits.  This requires an additional step
+ * in the 16-bit case.
+ *
+ * We want log2(value/65535), we have log2(v'/255), where:
+ *
+ *    value = v' * 256 + v''
+ *          = v' * f
+ *
+ * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128
+ * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less
+ * than 258.  The final factor also needs to correct for the fact that our 8-bit
+ * value is scaled by 255, whereas the 16-bit values must be scaled by 65535.
+ *
+ * This gives a final formula using a calculated value 'x' which is value/v' and
+ * scaling by 65536 to match the above table:
+ *
+ *   log2(x/257) * 65536
+ *
+ * Since these numbers are so close to '1' we can use simple linear
+ * interpolation between the two end values 256/257 (result -368.61) and 258/257
+ * (result 367.179).  The values used below are scaled by a further 64 to give
+ * 16-bit precision in the interpolation:
+ *
+ * Start (256): -23591
+ * Zero  (257):      0
+ * End   (258):  23499
+ */
+#ifdef PNG_16BIT_SUPPORTED
+static png_int_32
+png_log16bit(png_uint_32 x)
+{
+   unsigned int lg2 = 0;
+
+   /* As above, but now the input has 16 bits. */
+   if ((x &= 0xffff) == 0)
+      return -1;
+
+   if ((x & 0xff00) == 0)
+      lg2  = 8, x <<= 8;
+
+   if ((x & 0xf000) == 0)
+      lg2 += 4, x <<= 4;
+
+   if ((x & 0xc000) == 0)
+      lg2 += 2, x <<= 2;
+
+   if ((x & 0x8000) == 0)
+      lg2 += 1, x <<= 1;
+
+   /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional
+    * value.
+    */
+   lg2 <<= 28;
+   lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4;
+
+   /* Now we need to interpolate the factor, this requires a division by the top
+    * 8 bits.  Do this with maximum precision.
+    */
+   x = ((x << 16) + (x >> 9)) / (x >> 8);
+
+   /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24,
+    * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly
+    * 16 bits to interpolate to get the low bits of the result.  Round the
+    * answer.  Note that the end point values are scaled by 64 to retain overall
+    * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust
+    * the overall scaling by 6-12.  Round at every step.
+    */
+   x -= 1U << 24;
+
+   if (x <= 65536U) /* <= '257' */
+      lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12);
+
+   else
+      lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12);
+
+   /* Safe, because the result can't have more than 20 bits: */
+   return (png_int_32)((lg2 + 2048) >> 12);
+}
+#endif /* 16BIT */
+
+/* The 'exp()' case must invert the above, taking a 20-bit fixed point
+ * logarithmic value and returning a 16 or 8-bit number as appropriate.  In
+ * each case only the low 16 bits are relevant - the fraction - since the
+ * integer bits (the top 4) simply determine a shift.
+ *
+ * The worst case is the 16-bit distinction between 65535 and 65534. This
+ * requires perhaps spurious accuracy in the decoding of the logarithm to
+ * distinguish log2(65535/65534.5) - 10^-5 or 17 bits.  There is little chance
+ * of getting this accuracy in practice.
+ *
+ * To deal with this the following exp() function works out the exponent of the
+ * fractional part of the logarithm by using an accurate 32-bit value from the
+ * top four fractional bits then multiplying in the remaining bits.
+ */
+static const png_uint_32
+png_32bit_exp[16] =
+{
+   /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */
+   4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U,
+   3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U,
+   2553802834U, 2445529972U, 2341847524U, 2242560872U
+};
+
+/* Adjustment table; provided to explain the numbers in the code below. */
+#if 0
+for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"}
+   11 44937.64284865548751208448
+   10 45180.98734845585101160448
+    9 45303.31936980687359311872
+    8 45364.65110595323018870784
+    7 45395.35850361789624614912
+    6 45410.72259715102037508096
+    5 45418.40724413220722311168
+    4 45422.25021786898173001728
+    3 45424.17186732298419044352
+    2 45425.13273269940811464704
+    1 45425.61317555035558641664
+    0 45425.85339951654943850496
+#endif
+
+static png_uint_32
+png_exp(png_fixed_point x)
+{
+   if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */
+   {
+      /* Obtain a 4-bit approximation */
+      png_uint_32 e = png_32bit_exp[(x >> 12) & 0x0f];
+
+      /* Incorporate the low 12 bits - these decrease the returned value by
+       * multiplying by a number less than 1 if the bit is set.  The multiplier
+       * is determined by the above table and the shift. Notice that the values
+       * converge on 45426 and this is used to allow linear interpolation of the
+       * low bits.
+       */
+      if (x & 0x800)
+         e -= (((e >> 16) * 44938U) +  16U) >> 5;
+
+      if (x & 0x400)
+         e -= (((e >> 16) * 45181U) +  32U) >> 6;
+
+      if (x & 0x200)
+         e -= (((e >> 16) * 45303U) +  64U) >> 7;
+
+      if (x & 0x100)
+         e -= (((e >> 16) * 45365U) + 128U) >> 8;
+
+      if (x & 0x080)
+         e -= (((e >> 16) * 45395U) + 256U) >> 9;
+
+      if (x & 0x040)
+         e -= (((e >> 16) * 45410U) + 512U) >> 10;
+
+      /* And handle the low 6 bits in a single block. */
+      e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9;
+
+      /* Handle the upper bits of x. */
+      e >>= x >> 16;
+      return e;
+   }
+
+   /* Check for overflow */
+   if (x <= 0)
+      return png_32bit_exp[0];
+
+   /* Else underflow */
+   return 0;
+}
+
+static png_byte
+png_exp8bit(png_fixed_point lg2)
+{
+   /* Get a 32-bit value: */
+   png_uint_32 x = png_exp(lg2);
+
+   /* Convert the 32-bit value to 0..255 by multiplying by 256-1. Note that the
+    * second, rounding, step can't overflow because of the first, subtraction,
+    * step.
+    */
+   x -= x >> 8;
+   return (png_byte)(((x + 0x7fffffU) >> 24) & 0xff);
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+static png_uint_16
+png_exp16bit(png_fixed_point lg2)
+{
+   /* Get a 32-bit value: */
+   png_uint_32 x = png_exp(lg2);
+
+   /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */
+   x -= x >> 16;
+   return (png_uint_16)((x + 32767U) >> 16);
+}
+#endif /* 16BIT */
+#endif /* FLOATING_ARITHMETIC */
+
+png_byte
+png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+   if (value > 0 && value < 255)
+   {
+#     ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+         /* 'value' is unsigned, ANSI-C90 requires the compiler to correctly
+          * convert this to a floating point value.  This includes values that
+          * would overflow if 'value' were to be converted to 'int'.
+          *
+          * Apparently GCC, however, does an intermediate conversion to (int)
+          * on some (ARM) but not all (x86) platforms, possibly because of
+          * hardware FP limitations.  (E.g. if the hardware conversion always
+          * assumes the integer register contains a signed value.)  This results
+          * in ANSI-C undefined behavior for large values.
+          *
+          * Other implementations on the same machine might actually be ANSI-C90
+          * conformant and therefore compile spurious extra code for the large
+          * values.
+          *
+          * We can be reasonably sure that an unsigned to float conversion
+          * won't be faster than an int to float one.  Therefore this code
+          * assumes responsibility for the undefined behavior, which it knows
+          * can't happen because of the check above.
+          *
+          * Note the argument to this routine is an (unsigned int) because, on
+          * 16-bit platforms, it is assigned a value which might be out of
+          * range for an (int); that would result in undefined behavior in the
+          * caller if the *argument* ('value') were to be declared (int).
+          */
+         double r = floor(255*pow((int)/*SAFE*/value/255.,gamma_val*.00001)+.5);
+         return (png_byte)r;
+#     else
+         png_int_32 lg2 = png_log8bit(value);
+         png_fixed_point res;
+
+         if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+            return png_exp8bit(res);
+
+         /* Overflow. */
+         value = 0;
+#     endif
+   }
+
+   return (png_byte)(value & 0xff);
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+png_uint_16
+png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
+{
+   if (value > 0 && value < 65535)
+   {
+# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+      /* The same (unsigned int)->(double) constraints apply here as above,
+       * however in this case the (unsigned int) to (int) conversion can
+       * overflow on an ANSI-C90 compliant system so the cast needs to ensure
+       * that this is not possible.
+       */
+      double r = floor(65535*pow((png_int_32)value/65535.,
+          gamma_val*.00001)+.5);
+      return (png_uint_16)r;
+# else
+      png_int_32 lg2 = png_log16bit(value);
+      png_fixed_point res;
+
+      if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1) != 0)
+         return png_exp16bit(res);
+
+      /* Overflow. */
+      value = 0;
+# endif
+   }
+
+   return (png_uint_16)value;
+}
+#endif /* 16BIT */
+
+/* This does the right thing based on the bit_depth field of the
+ * png_struct, interpreting values as 8-bit or 16-bit.  While the result
+ * is nominally a 16-bit value if bit depth is 8 then the result is
+ * 8-bit (as are the arguments.)
+ */
+png_uint_16 /* PRIVATE */
+png_gamma_correct(png_structrp png_ptr, unsigned int value,
+    png_fixed_point gamma_val)
+{
+   if (png_ptr->bit_depth == 8)
+      return png_gamma_8bit_correct(value, gamma_val);
+
+#ifdef PNG_16BIT_SUPPORTED
+   else
+      return png_gamma_16bit_correct(value, gamma_val);
+#else
+      /* should not reach this */
+      return 0;
+#endif /* 16BIT */
+}
+
+#ifdef PNG_16BIT_SUPPORTED
+/* Internal function to build a single 16-bit table - the table consists of
+ * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
+ * to shift the input values right (or 16-number_of_signifiant_bits).
+ *
+ * The caller is responsible for ensuring that the table gets cleaned up on
+ * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument
+ * should be somewhere that will be cleaned.
+ */
+static void
+png_build_16bit_table(png_structrp png_ptr, png_uint_16pp *ptable,
+    PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+{
+   /* Various values derived from 'shift': */
+   PNG_CONST unsigned int num = 1U << (8U - shift);
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+   /* CSE the division and work round wacky GCC warnings (see the comments
+    * in png_gamma_8bit_correct for where these come from.)
+    */
+   PNG_CONST double fmax = 1./(((png_int_32)1 << (16U - shift))-1);
+#endif
+   PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+   PNG_CONST unsigned int max_by_2 = 1U << (15U-shift);
+   unsigned int i;
+
+   png_uint_16pp table = *ptable =
+       (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
+
+   for (i = 0; i < num; i++)
+   {
+      png_uint_16p sub_table = table[i] =
+          (png_uint_16p)png_malloc(png_ptr, 256 * (sizeof (png_uint_16)));
+
+      /* The 'threshold' test is repeated here because it can arise for one of
+       * the 16-bit tables even if the others don't hit it.
+       */
+      if (png_gamma_significant(gamma_val) != 0)
+      {
+         /* The old code would overflow at the end and this would cause the
+          * 'pow' function to return a result >1, resulting in an
+          * arithmetic error.  This code follows the spec exactly; ig is
+          * the recovered input sample, it always has 8-16 bits.
+          *
+          * We want input * 65535/max, rounded, the arithmetic fits in 32
+          * bits (unsigned) so long as max <= 32767.
+          */
+         unsigned int j;
+         for (j = 0; j < 256; j++)
+         {
+            png_uint_32 ig = (j << (8-shift)) + i;
+#           ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+               /* Inline the 'max' scaling operation: */
+               /* See png_gamma_8bit_correct for why the cast to (int) is
+                * required here.
+                */
+               double d = floor(65535.*pow(ig*fmax, gamma_val*.00001)+.5);
+               sub_table[j] = (png_uint_16)d;
+#           else
+               if (shift != 0)
+                  ig = (ig * 65535U + max_by_2)/max;
+
+               sub_table[j] = png_gamma_16bit_correct(ig, gamma_val);
+#           endif
+         }
+      }
+      else
+      {
+         /* We must still build a table, but do it the fast way. */
+         unsigned int j;
+
+         for (j = 0; j < 256; j++)
+         {
+            png_uint_32 ig = (j << (8-shift)) + i;
+
+            if (shift != 0)
+               ig = (ig * 65535U + max_by_2)/max;
+
+            sub_table[j] = (png_uint_16)ig;
+         }
+      }
+   }
+}
+
+/* NOTE: this function expects the *inverse* of the overall gamma transformation
+ * required.
+ */
+static void
+png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
+    PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val)
+{
+   PNG_CONST unsigned int num = 1U << (8U - shift);
+   PNG_CONST unsigned int max = (1U << (16U - shift))-1U;
+   unsigned int i;
+   png_uint_32 last;
+
+   png_uint_16pp table = *ptable =
+       (png_uint_16pp)png_calloc(png_ptr, num * (sizeof (png_uint_16p)));
+
+   /* 'num' is the number of tables and also the number of low bits of low
+    * bits of the input 16-bit value used to select a table.  Each table is
+    * itself indexed by the high 8 bits of the value.
+    */
+   for (i = 0; i < num; i++)
+      table[i] = (png_uint_16p)png_malloc(png_ptr,
+          256 * (sizeof (png_uint_16)));
+
+   /* 'gamma_val' is set to the reciprocal of the value calculated above, so
+    * pow(out,g) is an *input* value.  'last' is the last input value set.
+    *
+    * In the loop 'i' is used to find output values.  Since the output is
+    * 8-bit there are only 256 possible values.  The tables are set up to
+    * select the closest possible output value for each input by finding
+    * the input value at the boundary between each pair of output values
+    * and filling the table up to that boundary with the lower output
+    * value.
+    *
+    * The boundary values are 0.5,1.5..253.5,254.5.  Since these are 9-bit
+    * values the code below uses a 16-bit value in i; the values start at
+    * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last
+    * entries are filled with 255).  Start i at 128 and fill all 'last'
+    * table entries <= 'max'
+    */
+   last = 0;
+   for (i = 0; i < 255; ++i) /* 8-bit output value */
+   {
+      /* Find the corresponding maximum input value */
+      png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */
+
+      /* Find the boundary value in 16 bits: */
+      png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val);
+
+      /* Adjust (round) to (16-shift) bits: */
+      bound = (bound * max + 32768U)/65535U + 1U;
+
+      while (last < bound)
+      {
+         table[last & (0xffU >> shift)][last >> (8U - shift)] = out;
+         last++;
+      }
+   }
+
+   /* And fill in the final entries. */
+   while (last < (num << 8))
+   {
+      table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U;
+      last++;
+   }
+}
+#endif /* 16BIT */
+
+/* Build a single 8-bit table: same as the 16-bit case but much simpler (and
+ * typically much faster).  Note that libpng currently does no sBIT processing
+ * (apparently contrary to the spec) so a 256-entry table is always generated.
+ */
+static void
+png_build_8bit_table(png_structrp png_ptr, png_bytepp ptable,
+    PNG_CONST png_fixed_point gamma_val)
+{
+   unsigned int i;
+   png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256);
+
+   if (png_gamma_significant(gamma_val) != 0)
+      for (i=0; i<256; i++)
+         table[i] = png_gamma_8bit_correct(i, gamma_val);
+
+   else
+      for (i=0; i<256; ++i)
+         table[i] = (png_byte)(i & 0xff);
+}
+
+/* Used from png_read_destroy and below to release the memory used by the gamma
+ * tables.
+ */
+void /* PRIVATE */
+png_destroy_gamma_table(png_structrp png_ptr)
+{
+   png_free(png_ptr, png_ptr->gamma_table);
+   png_ptr->gamma_table = NULL;
+
+#ifdef PNG_16BIT_SUPPORTED
+   if (png_ptr->gamma_16_table != NULL)
+   {
+      int i;
+      int istop = (1 << (8 - png_ptr->gamma_shift));
+      for (i = 0; i < istop; i++)
+      {
+         png_free(png_ptr, png_ptr->gamma_16_table[i]);
+      }
+   png_free(png_ptr, png_ptr->gamma_16_table);
+   png_ptr->gamma_16_table = NULL;
+   }
+#endif /* 16BIT */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_free(png_ptr, png_ptr->gamma_from_1);
+   png_ptr->gamma_from_1 = NULL;
+   png_free(png_ptr, png_ptr->gamma_to_1);
+   png_ptr->gamma_to_1 = NULL;
+
+#ifdef PNG_16BIT_SUPPORTED
+   if (png_ptr->gamma_16_from_1 != NULL)
+   {
+      int i;
+      int istop = (1 << (8 - png_ptr->gamma_shift));
+      for (i = 0; i < istop; i++)
+      {
+         png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
+      }
+   png_free(png_ptr, png_ptr->gamma_16_from_1);
+   png_ptr->gamma_16_from_1 = NULL;
+   }
+   if (png_ptr->gamma_16_to_1 != NULL)
+   {
+      int i;
+      int istop = (1 << (8 - png_ptr->gamma_shift));
+      for (i = 0; i < istop; i++)
+      {
+         png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
+      }
+   png_free(png_ptr, png_ptr->gamma_16_to_1);
+   png_ptr->gamma_16_to_1 = NULL;
+   }
+#endif /* 16BIT */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+}
+
+/* We build the 8- or 16-bit gamma tables here.  Note that for 16-bit
+ * tables, we don't make a full table if we are reducing to 8-bit in
+ * the future.  Note also how the gamma_16 tables are segmented so that
+ * we don't need to allocate > 64K chunks for a full 16-bit table.
+ */
+void /* PRIVATE */
+png_build_gamma_table(png_structrp png_ptr, int bit_depth)
+{
+   png_debug(1, "in png_build_gamma_table");
+
+   /* Remove any existing table; this copes with multiple calls to
+    * png_read_update_info. The warning is because building the gamma tables
+    * multiple times is a performance hit - it's harmless but the ability to
+    * call png_read_update_info() multiple times is new in 1.5.6 so it seems
+    * sensible to warn if the app introduces such a hit.
+    */
+   if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
+   {
+      png_warning(png_ptr, "gamma table being rebuilt");
+      png_destroy_gamma_table(png_ptr);
+   }
+
+   if (bit_depth <= 8)
+   {
+      png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
+          png_ptr->screen_gamma > 0 ?
+          png_reciprocal2(png_ptr->colorspace.gamma,
+          png_ptr->screen_gamma) : PNG_FP_1);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+      if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+      {
+         png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
+             png_reciprocal(png_ptr->colorspace.gamma));
+
+         png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
+             png_ptr->screen_gamma > 0 ?
+             png_reciprocal(png_ptr->screen_gamma) :
+             png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
+      }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+   }
+#ifdef PNG_16BIT_SUPPORTED
+   else
+   {
+      png_byte shift, sig_bit;
+
+      if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      {
+         sig_bit = png_ptr->sig_bit.red;
+
+         if (png_ptr->sig_bit.green > sig_bit)
+            sig_bit = png_ptr->sig_bit.green;
+
+         if (png_ptr->sig_bit.blue > sig_bit)
+            sig_bit = png_ptr->sig_bit.blue;
+      }
+      else
+         sig_bit = png_ptr->sig_bit.gray;
+
+      /* 16-bit gamma code uses this equation:
+       *
+       *   ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
+       *
+       * Where 'iv' is the input color value and 'ov' is the output value -
+       * pow(iv, gamma).
+       *
+       * Thus the gamma table consists of up to 256 256-entry tables.  The table
+       * is selected by the (8-gamma_shift) most significant of the low 8 bits
+       * of the color value then indexed by the upper 8 bits:
+       *
+       *   table[low bits][high 8 bits]
+       *
+       * So the table 'n' corresponds to all those 'iv' of:
+       *
+       *   <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
+       *
+       */
+      if (sig_bit > 0 && sig_bit < 16U)
+         /* shift == insignificant bits */
+         shift = (png_byte)((16U - sig_bit) & 0xff);
+
+      else
+         shift = 0; /* keep all 16 bits */
+
+      if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+      {
+         /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
+          * the significant bits in the *input* when the output will
+          * eventually be 8 bits.  By default it is 11.
+          */
+         if (shift < (16U - PNG_MAX_GAMMA_8))
+            shift = (16U - PNG_MAX_GAMMA_8);
+      }
+
+      if (shift > 8U)
+         shift = 8U; /* Guarantees at least one table! */
+
+      png_ptr->gamma_shift = shift;
+
+      /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
+       * PNG_COMPOSE).  This effectively smashed the background calculation for
+       * 16-bit output because the 8-bit table assumes the result will be
+       * reduced to 8 bits.
+       */
+      if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
+          png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
+          png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
+          png_ptr->screen_gamma) : PNG_FP_1);
+
+      else
+          png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
+          png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
+          png_ptr->screen_gamma) : PNG_FP_1);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+      if ((png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY)) != 0)
+      {
+         png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
+             png_reciprocal(png_ptr->colorspace.gamma));
+
+         /* Notice that the '16 from 1' table should be full precision, however
+          * the lookup on this table still uses gamma_shift, so it can't be.
+          * TODO: fix this.
+          */
+         png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift,
+             png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
+             png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
+      }
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+   }
+#endif /* 16BIT */
+}
+#endif /* READ_GAMMA */
+
+/* HARDWARE OR SOFTWARE OPTION SUPPORT */
+#ifdef PNG_SET_OPTION_SUPPORTED
+int PNGAPI
+png_set_option(png_structrp png_ptr, int option, int onoff)
+{
+   if (png_ptr != NULL && option >= 0 && option < PNG_OPTION_NEXT &&
+      (option & 1) == 0)
+   {
+      png_uint_32 mask = 3U << option;
+      png_uint_32 setting = (2U + (onoff != 0)) << option;
+      png_uint_32 current = png_ptr->options;
+
+      png_ptr->options = (png_uint_32)(((current & ~mask) | setting) & 0xff);
+
+      return (int)(current & mask) >> option;
+   }
+
+   return PNG_OPTION_INVALID;
+}
+#endif
+
+/* sRGB support */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+/* sRGB conversion tables; these are machine generated with the code in
+ * contrib/tools/makesRGB.c.  The actual sRGB transfer curve defined in the
+ * specification (see the article at https://en.wikipedia.org/wiki/SRGB)
+ * is used, not the gamma=1/2.2 approximation use elsewhere in libpng.
+ * The sRGB to linear table is exact (to the nearest 16-bit linear fraction).
+ * The inverse (linear to sRGB) table has accuracies as follows:
+ *
+ * For all possible (255*65535+1) input values:
+ *
+ *    error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact
+ *
+ * For the input values corresponding to the 65536 16-bit values:
+ *
+ *    error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact
+ *
+ * In all cases the inexact readings are only off by one.
+ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* The convert-to-sRGB table is only currently required for read. */
+const png_uint_16 png_sRGB_table[256] =
+{
+   0,20,40,60,80,99,119,139,
+   159,179,199,219,241,264,288,313,
+   340,367,396,427,458,491,526,562,
+   599,637,677,718,761,805,851,898,
+   947,997,1048,1101,1156,1212,1270,1330,
+   1391,1453,1517,1583,1651,1720,1790,1863,
+   1937,2013,2090,2170,2250,2333,2418,2504,
+   2592,2681,2773,2866,2961,3058,3157,3258,
+   3360,3464,3570,3678,3788,3900,4014,4129,
+   4247,4366,4488,4611,4736,4864,4993,5124,
+   5257,5392,5530,5669,5810,5953,6099,6246,
+   6395,6547,6700,6856,7014,7174,7335,7500,
+   7666,7834,8004,8177,8352,8528,8708,8889,
+   9072,9258,9445,9635,9828,10022,10219,10417,
+   10619,10822,11028,11235,11446,11658,11873,12090,
+   12309,12530,12754,12980,13209,13440,13673,13909,
+   14146,14387,14629,14874,15122,15371,15623,15878,
+   16135,16394,16656,16920,17187,17456,17727,18001,
+   18277,18556,18837,19121,19407,19696,19987,20281,
+   20577,20876,21177,21481,21787,22096,22407,22721,
+   23038,23357,23678,24002,24329,24658,24990,25325,
+   25662,26001,26344,26688,27036,27386,27739,28094,
+   28452,28813,29176,29542,29911,30282,30656,31033,
+   31412,31794,32179,32567,32957,33350,33745,34143,
+   34544,34948,35355,35764,36176,36591,37008,37429,
+   37852,38278,38706,39138,39572,40009,40449,40891,
+   41337,41785,42236,42690,43147,43606,44069,44534,
+   45002,45473,45947,46423,46903,47385,47871,48359,
+   48850,49344,49841,50341,50844,51349,51858,52369,
+   52884,53401,53921,54445,54971,55500,56032,56567,
+   57105,57646,58190,58737,59287,59840,60396,60955,
+   61517,62082,62650,63221,63795,64372,64952,65535
+};
+#endif /* SIMPLIFIED_READ */
+
+/* The base/delta tables are required for both read and write (but currently
+ * only the simplified versions.)
+ */
+const png_uint_16 png_sRGB_base[512] =
+{
+   128,1782,3383,4644,5675,6564,7357,8074,
+   8732,9346,9921,10463,10977,11466,11935,12384,
+   12816,13233,13634,14024,14402,14769,15125,15473,
+   15812,16142,16466,16781,17090,17393,17690,17981,
+   18266,18546,18822,19093,19359,19621,19879,20133,
+   20383,20630,20873,21113,21349,21583,21813,22041,
+   22265,22487,22707,22923,23138,23350,23559,23767,
+   23972,24175,24376,24575,24772,24967,25160,25352,
+   25542,25730,25916,26101,26284,26465,26645,26823,
+   27000,27176,27350,27523,27695,27865,28034,28201,
+   28368,28533,28697,28860,29021,29182,29341,29500,
+   29657,29813,29969,30123,30276,30429,30580,30730,
+   30880,31028,31176,31323,31469,31614,31758,31902,
+   32045,32186,32327,32468,32607,32746,32884,33021,
+   33158,33294,33429,33564,33697,33831,33963,34095,
+   34226,34357,34486,34616,34744,34873,35000,35127,
+   35253,35379,35504,35629,35753,35876,35999,36122,
+   36244,36365,36486,36606,36726,36845,36964,37083,
+   37201,37318,37435,37551,37668,37783,37898,38013,
+   38127,38241,38354,38467,38580,38692,38803,38915,
+   39026,39136,39246,39356,39465,39574,39682,39790,
+   39898,40005,40112,40219,40325,40431,40537,40642,
+   40747,40851,40955,41059,41163,41266,41369,41471,
+   41573,41675,41777,41878,41979,42079,42179,42279,
+   42379,42478,42577,42676,42775,42873,42971,43068,
+   43165,43262,43359,43456,43552,43648,43743,43839,
+   43934,44028,44123,44217,44311,44405,44499,44592,
+   44685,44778,44870,44962,45054,45146,45238,45329,
+   45420,45511,45601,45692,45782,45872,45961,46051,
+   46140,46229,46318,46406,46494,46583,46670,46758,
+   46846,46933,47020,47107,47193,47280,47366,47452,
+   47538,47623,47709,47794,47879,47964,48048,48133,
+   48217,48301,48385,48468,48552,48635,48718,48801,
+   48884,48966,49048,49131,49213,49294,49376,49458,
+   49539,49620,49701,49782,49862,49943,50023,50103,
+   50183,50263,50342,50422,50501,50580,50659,50738,
+   50816,50895,50973,51051,51129,51207,51285,51362,
+   51439,51517,51594,51671,51747,51824,51900,51977,
+   52053,52129,52205,52280,52356,52432,52507,52582,
+   52657,52732,52807,52881,52956,53030,53104,53178,
+   53252,53326,53400,53473,53546,53620,53693,53766,
+   53839,53911,53984,54056,54129,54201,54273,54345,
+   54417,54489,54560,54632,54703,54774,54845,54916,
+   54987,55058,55129,55199,55269,55340,55410,55480,
+   55550,55620,55689,55759,55828,55898,55967,56036,
+   56105,56174,56243,56311,56380,56448,56517,56585,
+   56653,56721,56789,56857,56924,56992,57059,57127,
+   57194,57261,57328,57395,57462,57529,57595,57662,
+   57728,57795,57861,57927,57993,58059,58125,58191,
+   58256,58322,58387,58453,58518,58583,58648,58713,
+   58778,58843,58908,58972,59037,59101,59165,59230,
+   59294,59358,59422,59486,59549,59613,59677,59740,
+   59804,59867,59930,59993,60056,60119,60182,60245,
+   60308,60370,60433,60495,60558,60620,60682,60744,
+   60806,60868,60930,60992,61054,61115,61177,61238,
+   61300,61361,61422,61483,61544,61605,61666,61727,
+   61788,61848,61909,61969,62030,62090,62150,62211,
+   62271,62331,62391,62450,62510,62570,62630,62689,
+   62749,62808,62867,62927,62986,63045,63104,63163,
+   63222,63281,63340,63398,63457,63515,63574,63632,
+   63691,63749,63807,63865,63923,63981,64039,64097,
+   64155,64212,64270,64328,64385,64443,64500,64557,
+   64614,64672,64729,64786,64843,64900,64956,65013,
+   65070,65126,65183,65239,65296,65352,65409,65465
+};
+
+const png_byte png_sRGB_delta[512] =
+{
+   207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54,
+   52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36,
+   35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28,
+   28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24,
+   23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21,
+   21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19,
+   19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17,
+   17,17,17,17,17,17,16,16,16,16,16,16,16,16,16,16,
+   16,16,16,16,15,15,15,15,15,15,15,15,15,15,15,15,
+   15,15,15,15,14,14,14,14,14,14,14,14,14,14,14,14,
+   14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13,
+   13,13,13,13,13,13,13,13,13,13,13,13,13,13,12,12,
+   12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,
+   12,12,12,12,12,12,12,12,12,12,12,12,11,11,11,11,
+   11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
+   11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
+   11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+   10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+   10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
+   10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+   9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+   9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+   9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+   9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+   8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+   8,8,8,8,8,8,8,8,8,7,7,7,7,7,7,7,
+   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
+};
+#endif /* SIMPLIFIED READ/WRITE sRGB support */
+
+/* SIMPLIFIED READ/WRITE SUPPORT */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+static int
+png_image_free_function(png_voidp argument)
+{
+   png_imagep image = png_voidcast(png_imagep, argument);
+   png_controlp cp = image->opaque;
+   png_control c;
+
+   /* Double check that we have a png_ptr - it should be impossible to get here
+    * without one.
+    */
+   if (cp->png_ptr == NULL)
+      return 0;
+
+   /* First free any data held in the control structure. */
+#  ifdef PNG_STDIO_SUPPORTED
+      if (cp->owned_file != 0)
+      {
+         FILE *fp = png_voidcast(FILE*, cp->png_ptr->io_ptr);
+         cp->owned_file = 0;
+
+         /* Ignore errors here. */
+         if (fp != NULL)
+         {
+            cp->png_ptr->io_ptr = NULL;
+            (void)fclose(fp);
+         }
+      }
+#  endif
+
+   /* Copy the control structure so that the original, allocated, version can be
+    * safely freed.  Notice that a png_error here stops the remainder of the
+    * cleanup, but this is probably fine because that would indicate bad memory
+    * problems anyway.
+    */
+   c = *cp;
+   image->opaque = &c;
+   png_free(c.png_ptr, cp);
+
+   /* Then the structures, calling the correct API. */
+   if (c.for_write != 0)
+   {
+#     ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+         png_destroy_write_struct(&c.png_ptr, &c.info_ptr);
+#     else
+         png_error(c.png_ptr, "simplified write not supported");
+#     endif
+   }
+   else
+   {
+#     ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+         png_destroy_read_struct(&c.png_ptr, &c.info_ptr, NULL);
+#     else
+         png_error(c.png_ptr, "simplified read not supported");
+#     endif
+   }
+
+   /* Success. */
+   return 1;
+}
+
+void PNGAPI
+png_image_free(png_imagep image)
+{
+   /* Safely call the real function, but only if doing so is safe at this point
+    * (if not inside an error handling context).  Otherwise assume
+    * png_safe_execute will call this API after the return.
+    */
+   if (image != NULL && image->opaque != NULL &&
+      image->opaque->error_buf == NULL)
+   {
+      /* Ignore errors here: */
+      (void)png_safe_execute(image, png_image_free_function, image);
+      image->opaque = NULL;
+   }
+}
+
+int /* PRIVATE */
+png_image_error(png_imagep image, png_const_charp error_message)
+{
+   /* Utility to log an error. */
+   png_safecat(image->message, (sizeof image->message), 0, error_message);
+   image->warning_or_error |= PNG_IMAGE_ERROR;
+   png_image_free(image);
+   return 0;
+}
+
+#endif /* SIMPLIFIED READ/WRITE */
+#endif /* READ || WRITE */
diff --git a/xs/src/png/libpng/png.h b/xs/src/png/libpng/png.h
new file mode 100644
index 000000000..4c873f5c2
--- /dev/null
+++ b/xs/src/png/libpng/png.h
@@ -0,0 +1,3278 @@
+
+/* png.h - header file for PNG reference library
+ *
+ * libpng version 1.6.34, September 29, 2017
+ *
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license (See LICENSE, below)
+ *
+ * Authors and maintainers:
+ *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
+ *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
+ *   libpng versions 0.97, January 1998, through 1.6.34, September 29, 2017:
+ *     Glenn Randers-Pehrson.
+ *   See also "Contributing Authors", below.
+ */
+
+/*
+ * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+ *
+ * If you modify libpng you may insert additional notices immediately following
+ * this sentence.
+ *
+ * This code is released under the libpng license.
+ *
+ * libpng versions 1.0.7, July 1, 2000 through 1.6.34, September 29, 2017 are
+ * Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
+ * derived from libpng-1.0.6, and are distributed according to the same
+ * disclaimer and license as libpng-1.0.6 with the following individuals
+ * added to the list of Contributing Authors:
+ *
+ *    Simon-Pierre Cadieux
+ *    Eric S. Raymond
+ *    Mans Rullgard
+ *    Cosmin Truta
+ *    Gilles Vollant
+ *    James Yu
+ *    Mandar Sahastrabuddhe
+ *    Google Inc.
+ *    Vadim Barkov
+ *
+ * and with the following additions to the disclaimer:
+ *
+ *    There is no warranty against interference with your enjoyment of the
+ *    library or against infringement.  There is no warranty that our
+ *    efforts or the library will fulfill any of your particular purposes
+ *    or needs.  This library is provided with all faults, and the entire
+ *    risk of satisfactory quality, performance, accuracy, and effort is with
+ *    the user.
+ *
+ * Some files in the "contrib" directory and some configure-generated
+ * files that are distributed with libpng have other copyright owners and
+ * are released under other open source licenses.
+ *
+ * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+ * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+ * libpng-0.96, and are distributed according to the same disclaimer and
+ * license as libpng-0.96, with the following individuals added to the list
+ * of Contributing Authors:
+ *
+ *    Tom Lane
+ *    Glenn Randers-Pehrson
+ *    Willem van Schaik
+ *
+ * libpng versions 0.89, June 1996, through 0.96, May 1997, are
+ * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+ * and are distributed according to the same disclaimer and license as
+ * libpng-0.88, with the following individuals added to the list of
+ * Contributing Authors:
+ *
+ *    John Bowler
+ *    Kevin Bracey
+ *    Sam Bushell
+ *    Magnus Holmgren
+ *    Greg Roelofs
+ *    Tom Tanner
+ *
+ * Some files in the "scripts" directory have other copyright owners
+ * but are released under this license.
+ *
+ * libpng versions 0.5, May 1995, through 0.88, January 1996, are
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * For the purposes of this copyright and license, "Contributing Authors"
+ * is defined as the following set of individuals:
+ *
+ *    Andreas Dilger
+ *    Dave Martindale
+ *    Guy Eric Schalnat
+ *    Paul Schmidt
+ *    Tim Wegner
+ *
+ * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+ * and Group 42, Inc. disclaim all warranties, expressed or implied,
+ * including, without limitation, the warranties of merchantability and of
+ * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+ * assume no liability for direct, indirect, incidental, special, exemplary,
+ * or consequential damages, which may result from the use of the PNG
+ * Reference Library, even if advised of the possibility of such damage.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * source code, or portions hereof, for any purpose, without fee, subject
+ * to the following restrictions:
+ *
+ *   1. The origin of this source code must not be misrepresented.
+ *
+ *   2. Altered versions must be plainly marked as such and must not
+ *      be misrepresented as being the original source.
+ *
+ *   3. This Copyright notice may not be removed or altered from any
+ *      source or altered source distribution.
+ *
+ * The Contributing Authors and Group 42, Inc. specifically permit, without
+ * fee, and encourage the use of this source code as a component to
+ * supporting the PNG file format in commercial products.  If you use this
+ * source code in a product, acknowledgment is not required but would be
+ * appreciated.
+ *
+ * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
+ *
+ * TRADEMARK:
+ *
+ * The name "libpng" has not been registered by the Copyright owner
+ * as a trademark in any jurisdiction.  However, because libpng has
+ * been distributed and maintained world-wide, continually since 1995,
+ * the Copyright owner claims "common-law trademark protection" in any
+ * jurisdiction where common-law trademark is recognized.
+ *
+ * OSI CERTIFICATION:
+ *
+ * Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+ * a certification mark of the Open Source Initiative. OSI has not addressed
+ * the additional disclaimers inserted at version 1.0.7.
+ *
+ * EXPORT CONTROL:
+ *
+ * The Copyright owner believes that the Export Control Classification
+ * Number (ECCN) for libpng is EAR99, which means not subject to export
+ * controls or International Traffic in Arms Regulations (ITAR) because
+ * it is open source, publicly available software, that does not contain
+ * any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
+ * 734.7(b).
+ */
+
+/*
+ * A "png_get_copyright" function is available, for convenient use in "about"
+ * boxes and the like:
+ *
+ *    printf("%s", png_get_copyright(NULL));
+ *
+ * Also, the PNG logo (in PNG format, of course) is supplied in the
+ * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ */
+
+/*
+ * The contributing authors would like to thank all those who helped
+ * with testing, bug fixes, and patience.  This wouldn't have been
+ * possible without all of you.
+ *
+ * Thanks to Frank J. T. Wojcik for helping with the documentation.
+ */
+
+/* Note about libpng version numbers:
+ *
+ *    Due to various miscommunications, unforeseen code incompatibilities
+ *    and occasional factors outside the authors' control, version numbering
+ *    on the library has not always been consistent and straightforward.
+ *    The following table summarizes matters since version 0.89c, which was
+ *    the first widely used release:
+ *
+ *    source                 png.h  png.h  shared-lib
+ *    version                string   int  version
+ *    -------                ------ -----  ----------
+ *    0.89c "1.0 beta 3"     0.89      89  1.0.89
+ *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
+ *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
+ *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
+ *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
+ *    0.97c                  0.97      97  2.0.97
+ *    0.98                   0.98      98  2.0.98
+ *    0.99                   0.99      98  2.0.99
+ *    0.99a-m                0.99      99  2.0.99
+ *    1.00                   1.00     100  2.1.0 [100 should be 10000]
+ *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
+ *    1.0.1       png.h string is   10001  2.1.0
+ *    1.0.1a-e    identical to the  10002  from here on, the shared library
+ *    1.0.2       source version)   10002  is 2.V where V is the source code
+ *    1.0.2a-b                      10003  version, except as noted.
+ *    1.0.3                         10003
+ *    1.0.3a-d                      10004
+ *    1.0.4                         10004
+ *    1.0.4a-f                      10005
+ *    1.0.5 (+ 2 patches)           10005
+ *    1.0.5a-d                      10006
+ *    1.0.5e-r                      10100 (not source compatible)
+ *    1.0.5s-v                      10006 (not binary compatible)
+ *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
+ *    1.0.6d-f                      10007 (still binary incompatible)
+ *    1.0.6g                        10007
+ *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
+ *    1.0.6i                        10007  10.6i
+ *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
+ *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
+ *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
+ *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
+ *    1.0.7                    1    10007  (still compatible)
+ *    ...
+ *    1.0.19                  10    10019  10.so.0.19[.0]
+ *    ...
+ *    1.2.59                  13    10257  12.so.0.59[.0]
+ *    ...
+ *    1.5.30                  15    10527  15.so.15.30[.0]
+ *    ...
+ *    1.6.34                  16    10633  16.so.16.34[.0]
+ *
+ *    Henceforth the source version will match the shared-library major
+ *    and minor numbers; the shared-library major version number will be
+ *    used for changes in backward compatibility, as it is intended.  The
+ *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
+ *    for applications, is an unsigned integer of the form xyyzz corresponding
+ *    to the source version x.y.z (leading zeros in y and z).  Beta versions
+ *    were given the previous public release number plus a letter, until
+ *    version 1.0.6j; from then on they were given the upcoming public
+ *    release number plus "betaNN" or "rcNN".
+ *
+ *    Binary incompatibility exists only when applications make direct access
+ *    to the info_ptr or png_ptr members through png.h, and the compiled
+ *    application is loaded with a different version of the library.
+ *
+ *    DLLNUM will change each time there are forward or backward changes
+ *    in binary compatibility (e.g., when a new feature is added).
+ *
+ * See libpng.txt or libpng.3 for more information.  The PNG specification
+ * is available as a W3C Recommendation and as an ISO Specification,
+ * <https://www.w3.org/TR/2003/REC-PNG-20031110/
+ */
+
+/*
+ * Y2K compliance in libpng:
+ * =========================
+ *
+ *    September 29, 2017
+ *
+ *    Since the PNG Development group is an ad-hoc body, we can't make
+ *    an official declaration.
+ *
+ *    This is your unofficial assurance that libpng from version 0.71 and
+ *    upward through 1.6.34 are Y2K compliant.  It is my belief that
+ *    earlier versions were also Y2K compliant.
+ *
+ *    Libpng only has two year fields.  One is a 2-byte unsigned integer
+ *    that will hold years up to 65535.  The other, which is deprecated,
+ *    holds the date in text format, and will hold years up to 9999.
+ *
+ *    The integer is
+ *        "png_uint_16 year" in png_time_struct.
+ *
+ *    The string is
+ *        "char time_buffer[29]" in png_struct.  This is no longer used
+ *    in libpng-1.6.x and will be removed from libpng-1.7.0.
+ *
+ *    There are seven time-related functions:
+ *        png.c: png_convert_to_rfc_1123_buffer() in png.c
+ *          (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
+ *          png_convert_to_rfc_1152() in error prior to libpng-0.98)
+ *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+ *        png_convert_from_time_t() in pngwrite.c
+ *        png_get_tIME() in pngget.c
+ *        png_handle_tIME() in pngrutil.c, called in pngread.c
+ *        png_set_tIME() in pngset.c
+ *        png_write_tIME() in pngwutil.c, called in pngwrite.c
+ *
+ *    All handle dates properly in a Y2K environment.  The
+ *    png_convert_from_time_t() function calls gmtime() to convert from system
+ *    clock time, which returns (year - 1900), which we properly convert to
+ *    the full 4-digit year.  There is a possibility that libpng applications
+ *    are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
+ *    function, or that they are incorrectly passing only a 2-digit year
+ *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
+ *    but this is not under our control.  The libpng documentation has always
+ *    stated that it works with 4-digit years, and the APIs have been
+ *    documented as such.
+ *
+ *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+ *    integer to hold the year, and can hold years as large as 65535.
+ *
+ *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
+ *    no date-related code.
+ *
+ *       Glenn Randers-Pehrson
+ *       libpng maintainer
+ *       PNG Development Group
+ */
+
+#ifndef PNG_H
+#define PNG_H
+
+/* This is not the place to learn how to use libpng. The file libpng-manual.txt
+ * describes how to use libpng, and the file example.c summarizes it
+ * with some code on which to build.  This file is useful for looking
+ * at the actual function definitions and structure components.  If that
+ * file has been stripped from your copy of libpng, you can find it at
+ * <http://www.libpng.org/pub/png/libpng-manual.txt>
+ *
+ * If you just need to read a PNG file and don't want to read the documentation
+ * skip to the end of this file and read the section entitled 'simplified API'.
+ */
+
+/* Version information for png.h - this should match the version in png.c */
+#define PNG_LIBPNG_VER_STRING "1.6.34"
+#define PNG_HEADER_VERSION_STRING " libpng version 1.6.34 - September 29, 2017\n"
+
+#define PNG_LIBPNG_VER_SONUM   16
+#define PNG_LIBPNG_VER_DLLNUM  16
+
+/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
+#define PNG_LIBPNG_VER_MAJOR   1
+#define PNG_LIBPNG_VER_MINOR   6
+#define PNG_LIBPNG_VER_RELEASE 34
+
+/* This should match the numeric part of the final component of
+ * PNG_LIBPNG_VER_STRING, omitting any leading zero:
+ */
+
+#define PNG_LIBPNG_VER_BUILD  0
+
+/* Release Status */
+#define PNG_LIBPNG_BUILD_ALPHA    1
+#define PNG_LIBPNG_BUILD_BETA     2
+#define PNG_LIBPNG_BUILD_RC       3
+#define PNG_LIBPNG_BUILD_STABLE   4
+#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
+
+/* Release-Specific Flags */
+#define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
+                                       PNG_LIBPNG_BUILD_STABLE only */
+#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
+                                       PNG_LIBPNG_BUILD_SPECIAL */
+#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
+                                       PNG_LIBPNG_BUILD_PRIVATE */
+
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
+
+/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
+ * We must not include leading zeros.
+ * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
+ * version 1.0.0 was mis-numbered 100 instead of 10000).  From
+ * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
+ */
+#define PNG_LIBPNG_VER 10634 /* 1.6.34 */
+
+/* Library configuration: these options cannot be changed after
+ * the library has been built.
+ */
+#ifndef PNGLCONF_H
+/* If pnglibconf.h is missing, you can
+ * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
+ */
+#   include "pnglibconf.h"
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Machine specific configuration. */
+#  include "pngconf.h"
+#endif
+
+/*
+ * Added at libpng-1.2.8
+ *
+ * Ref MSDN: Private as priority over Special
+ * VS_FF_PRIVATEBUILD File *was not* built using standard release
+ * procedures. If this value is given, the StringFileInfo block must
+ * contain a PrivateBuild string.
+ *
+ * VS_FF_SPECIALBUILD File *was* built by the original company using
+ * standard release procedures but is a variation of the standard
+ * file of the same version number. If this value is given, the
+ * StringFileInfo block must contain a SpecialBuild string.
+ */
+
+#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
+#  define PNG_LIBPNG_BUILD_TYPE \
+       (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
+#else
+#  ifdef PNG_LIBPNG_SPECIALBUILD
+#    define PNG_LIBPNG_BUILD_TYPE \
+         (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
+#  else
+#    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
+#  endif
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* Version information for C files, stored in png.c.  This had better match
+ * the version above.
+ */
+#define png_libpng_ver png_get_header_ver(NULL)
+
+/* This file is arranged in several sections:
+ *
+ * 1. [omitted]
+ * 2. Any configuration options that can be specified by for the application
+ *    code when it is built.  (Build time configuration is in pnglibconf.h)
+ * 3. Type definitions (base types are defined in pngconf.h), structure
+ *    definitions.
+ * 4. Exported library functions.
+ * 5. Simplified API.
+ * 6. Implementation options.
+ *
+ * The library source code has additional files (principally pngpriv.h) that
+ * allow configuration of the library.
+ */
+
+/* Section 1: [omitted] */
+
+/* Section 2: run time configuration
+ * See pnglibconf.h for build time configuration
+ *
+ * Run time configuration allows the application to choose between
+ * implementations of certain arithmetic APIs.  The default is set
+ * at build time and recorded in pnglibconf.h, but it is safe to
+ * override these (and only these) settings.  Note that this won't
+ * change what the library does, only application code, and the
+ * settings can (and probably should) be made on a per-file basis
+ * by setting the #defines before including png.h
+ *
+ * Use macros to read integers from PNG data or use the exported
+ * functions?
+ *   PNG_USE_READ_MACROS: use the macros (see below)  Note that
+ *     the macros evaluate their argument multiple times.
+ *   PNG_NO_USE_READ_MACROS: call the relevant library function.
+ *
+ * Use the alternative algorithm for compositing alpha samples that
+ * does not use division?
+ *   PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
+ *      algorithm.
+ *   PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
+ *
+ * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
+ * false?
+ *   PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
+ *      APIs to png_warning.
+ * Otherwise the calls are mapped to png_error.
+ */
+
+/* Section 3: type definitions, including structures and compile time
+ * constants.
+ * See pngconf.h for base types that vary by machine/system
+ */
+
+/* This triggers a compiler error in png.c, if png.c and png.h
+ * do not agree upon the version number.
+ */
+typedef char* png_libpng_version_1_6_34;
+
+/* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
+ *
+ * png_struct is the cache of information used while reading or writing a single
+ * PNG file.  One of these is always required, although the simplified API
+ * (below) hides the creation and destruction of it.
+ */
+typedef struct png_struct_def png_struct;
+typedef const png_struct * png_const_structp;
+typedef png_struct * png_structp;
+typedef png_struct * * png_structpp;
+
+/* png_info contains information read from or to be written to a PNG file.  One
+ * or more of these must exist while reading or creating a PNG file.  The
+ * information is not used by libpng during read but is used to control what
+ * gets written when a PNG file is created.  "png_get_" function calls read
+ * information during read and "png_set_" functions calls write information
+ * when creating a PNG.
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_info_def png_info;
+typedef png_info * png_infop;
+typedef const png_info * png_const_infop;
+typedef png_info * * png_infopp;
+
+/* Types with names ending 'p' are pointer types.  The corresponding types with
+ * names ending 'rp' are identical pointer types except that the pointer is
+ * marked 'restrict', which means that it is the only pointer to the object
+ * passed to the function.  Applications should not use the 'restrict' types;
+ * it is always valid to pass 'p' to a pointer with a function argument of the
+ * corresponding 'rp' type.  Different compilers have different rules with
+ * regard to type matching in the presence of 'restrict'.  For backward
+ * compatibility libpng callbacks never have 'restrict' in their parameters and,
+ * consequentially, writing portable application code is extremely difficult if
+ * an attempt is made to use 'restrict'.
+ */
+typedef png_struct * PNG_RESTRICT png_structrp;
+typedef const png_struct * PNG_RESTRICT png_const_structrp;
+typedef png_info * PNG_RESTRICT png_inforp;
+typedef const png_info * PNG_RESTRICT png_const_inforp;
+
+/* Three color definitions.  The order of the red, green, and blue, (and the
+ * exact size) is not important, although the size of the fields need to
+ * be png_byte or png_uint_16 (as defined below).
+ */
+typedef struct png_color_struct
+{
+   png_byte red;
+   png_byte green;
+   png_byte blue;
+} png_color;
+typedef png_color * png_colorp;
+typedef const png_color * png_const_colorp;
+typedef png_color * * png_colorpp;
+
+typedef struct png_color_16_struct
+{
+   png_byte index;    /* used for palette files */
+   png_uint_16 red;   /* for use in red green blue files */
+   png_uint_16 green;
+   png_uint_16 blue;
+   png_uint_16 gray;  /* for use in grayscale files */
+} png_color_16;
+typedef png_color_16 * png_color_16p;
+typedef const png_color_16 * png_const_color_16p;
+typedef png_color_16 * * png_color_16pp;
+
+typedef struct png_color_8_struct
+{
+   png_byte red;   /* for use in red green blue files */
+   png_byte green;
+   png_byte blue;
+   png_byte gray;  /* for use in grayscale files */
+   png_byte alpha; /* for alpha channel files */
+} png_color_8;
+typedef png_color_8 * png_color_8p;
+typedef const png_color_8 * png_const_color_8p;
+typedef png_color_8 * * png_color_8pp;
+
+/*
+ * The following two structures are used for the in-core representation
+ * of sPLT chunks.
+ */
+typedef struct png_sPLT_entry_struct
+{
+   png_uint_16 red;
+   png_uint_16 green;
+   png_uint_16 blue;
+   png_uint_16 alpha;
+   png_uint_16 frequency;
+} png_sPLT_entry;
+typedef png_sPLT_entry * png_sPLT_entryp;
+typedef const png_sPLT_entry * png_const_sPLT_entryp;
+typedef png_sPLT_entry * * png_sPLT_entrypp;
+
+/*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
+ *  occupy the LSB of their respective members, and the MSB of each member
+ *  is zero-filled.  The frequency member always occupies the full 16 bits.
+ */
+
+typedef struct png_sPLT_struct
+{
+   png_charp name;           /* palette name */
+   png_byte depth;           /* depth of palette samples */
+   png_sPLT_entryp entries;  /* palette entries */
+   png_int_32 nentries;      /* number of palette entries */
+} png_sPLT_t;
+typedef png_sPLT_t * png_sPLT_tp;
+typedef const png_sPLT_t * png_const_sPLT_tp;
+typedef png_sPLT_t * * png_sPLT_tpp;
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
+ * and whether that contents is compressed or not.  The "key" field
+ * points to a regular zero-terminated C string.  The "text" fields can be a
+ * regular C string, an empty string, or a NULL pointer.
+ * However, the structure returned by png_get_text() will always contain
+ * the "text" field as a regular zero-terminated C string (possibly
+ * empty), never a NULL pointer, so it can be safely used in printf() and
+ * other string-handling functions.  Note that the "itxt_length", "lang", and
+ * "lang_key" members of the structure only exist when the library is built
+ * with iTXt chunk support.  Prior to libpng-1.4.0 the library was built by
+ * default without iTXt support. Also note that when iTXt *is* supported,
+ * the "lang" and "lang_key" fields contain NULL pointers when the
+ * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
+ * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
+ * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
+ * which is always 0 or 1, or its "compression method" which is always 0.
+ */
+typedef struct png_text_struct
+{
+   int  compression;       /* compression value:
+                             -1: tEXt, none
+                              0: zTXt, deflate
+                              1: iTXt, none
+                              2: iTXt, deflate  */
+   png_charp key;          /* keyword, 1-79 character description of "text" */
+   png_charp text;         /* comment, may be an empty string (ie "")
+                              or a NULL pointer */
+   png_size_t text_length; /* length of the text string */
+   png_size_t itxt_length; /* length of the itxt string */
+   png_charp lang;         /* language code, 0-79 characters
+                              or a NULL pointer */
+   png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
+                              chars or a NULL pointer */
+} png_text;
+typedef png_text * png_textp;
+typedef const png_text * png_const_textp;
+typedef png_text * * png_textpp;
+#endif
+
+/* Supported compression types for text in PNG files (tEXt, and zTXt).
+ * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
+#define PNG_TEXT_COMPRESSION_NONE_WR -3
+#define PNG_TEXT_COMPRESSION_zTXt_WR -2
+#define PNG_TEXT_COMPRESSION_NONE    -1
+#define PNG_TEXT_COMPRESSION_zTXt     0
+#define PNG_ITXT_COMPRESSION_NONE     1
+#define PNG_ITXT_COMPRESSION_zTXt     2
+#define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
+
+/* png_time is a way to hold the time in an machine independent way.
+ * Two conversions are provided, both from time_t and struct tm.  There
+ * is no portable way to convert to either of these structures, as far
+ * as I know.  If you know of a portable way, send it to me.  As a side
+ * note - PNG has always been Year 2000 compliant!
+ */
+typedef struct png_time_struct
+{
+   png_uint_16 year; /* full year, as in, 1995 */
+   png_byte month;   /* month of year, 1 - 12 */
+   png_byte day;     /* day of month, 1 - 31 */
+   png_byte hour;    /* hour of day, 0 - 23 */
+   png_byte minute;  /* minute of hour, 0 - 59 */
+   png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
+} png_time;
+typedef png_time * png_timep;
+typedef const png_time * png_const_timep;
+typedef png_time * * png_timepp;
+
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
+   defined(PNG_USER_CHUNKS_SUPPORTED)
+/* png_unknown_chunk is a structure to hold queued chunks for which there is
+ * no specific support.  The idea is that we can use this to queue
+ * up private chunks for output even though the library doesn't actually
+ * know about their semantics.
+ *
+ * The data in the structure is set by libpng on read and used on write.
+ */
+typedef struct png_unknown_chunk_t
+{
+   png_byte name[5]; /* Textual chunk name with '\0' terminator */
+   png_byte *data;   /* Data, should not be modified on read! */
+   png_size_t size;
+
+   /* On write 'location' must be set using the flag values listed below.
+    * Notice that on read it is set by libpng however the values stored have
+    * more bits set than are listed below.  Always treat the value as a
+    * bitmask.  On write set only one bit - setting multiple bits may cause the
+    * chunk to be written in multiple places.
+    */
+   png_byte location; /* mode of operation at read time */
+}
+png_unknown_chunk;
+
+typedef png_unknown_chunk * png_unknown_chunkp;
+typedef const png_unknown_chunk * png_const_unknown_chunkp;
+typedef png_unknown_chunk * * png_unknown_chunkpp;
+#endif
+
+/* Flag values for the unknown chunk location byte. */
+#define PNG_HAVE_IHDR  0x01
+#define PNG_HAVE_PLTE  0x02
+#define PNG_AFTER_IDAT 0x08
+
+/* Maximum positive integer used in PNG is (2^31)-1 */
+#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
+#define PNG_UINT_32_MAX ((png_uint_32)(-1))
+#define PNG_SIZE_MAX ((png_size_t)(-1))
+
+/* These are constants for fixed point values encoded in the
+ * PNG specification manner (x100000)
+ */
+#define PNG_FP_1    100000
+#define PNG_FP_HALF  50000
+#define PNG_FP_MAX  ((png_fixed_point)0x7fffffffL)
+#define PNG_FP_MIN  (-PNG_FP_MAX)
+
+/* These describe the color_type field in png_info. */
+/* color type masks */
+#define PNG_COLOR_MASK_PALETTE    1
+#define PNG_COLOR_MASK_COLOR      2
+#define PNG_COLOR_MASK_ALPHA      4
+
+/* color types.  Note that not all combinations are legal */
+#define PNG_COLOR_TYPE_GRAY 0
+#define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
+#define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
+#define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
+#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
+/* aliases */
+#define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
+#define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
+
+/* This is for compression type. PNG 1.0-1.2 only define the single type. */
+#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
+#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
+
+/* This is for filter type. PNG 1.0-1.2 only define the single type. */
+#define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
+#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
+#define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
+
+/* These are for the interlacing type.  These values should NOT be changed. */
+#define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
+#define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
+#define PNG_INTERLACE_LAST        2 /* Not a valid value */
+
+/* These are for the oFFs chunk.  These values should NOT be changed. */
+#define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
+#define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
+#define PNG_OFFSET_LAST           2 /* Not a valid value */
+
+/* These are for the pCAL chunk.  These values should NOT be changed. */
+#define PNG_EQUATION_LINEAR       0 /* Linear transformation */
+#define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
+#define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
+#define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
+#define PNG_EQUATION_LAST         4 /* Not a valid value */
+
+/* These are for the sCAL chunk.  These values should NOT be changed. */
+#define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
+#define PNG_SCALE_METER           1 /* meters per pixel */
+#define PNG_SCALE_RADIAN          2 /* radians per pixel */
+#define PNG_SCALE_LAST            3 /* Not a valid value */
+
+/* These are for the pHYs chunk.  These values should NOT be changed. */
+#define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
+#define PNG_RESOLUTION_METER      1 /* pixels/meter */
+#define PNG_RESOLUTION_LAST       2 /* Not a valid value */
+
+/* These are for the sRGB chunk.  These values should NOT be changed. */
+#define PNG_sRGB_INTENT_PERCEPTUAL 0
+#define PNG_sRGB_INTENT_RELATIVE   1
+#define PNG_sRGB_INTENT_SATURATION 2
+#define PNG_sRGB_INTENT_ABSOLUTE   3
+#define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
+
+/* This is for text chunks */
+#define PNG_KEYWORD_MAX_LENGTH     79
+
+/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
+#define PNG_MAX_PALETTE_LENGTH    256
+
+/* These determine if an ancillary chunk's data has been successfully read
+ * from the PNG header, or if the application has filled in the corresponding
+ * data in the info_struct to be written into the output file.  The values
+ * of the PNG_INFO_<chunk> defines should NOT be changed.
+ */
+#define PNG_INFO_gAMA 0x0001U
+#define PNG_INFO_sBIT 0x0002U
+#define PNG_INFO_cHRM 0x0004U
+#define PNG_INFO_PLTE 0x0008U
+#define PNG_INFO_tRNS 0x0010U
+#define PNG_INFO_bKGD 0x0020U
+#define PNG_INFO_hIST 0x0040U
+#define PNG_INFO_pHYs 0x0080U
+#define PNG_INFO_oFFs 0x0100U
+#define PNG_INFO_tIME 0x0200U
+#define PNG_INFO_pCAL 0x0400U
+#define PNG_INFO_sRGB 0x0800U  /* GR-P, 0.96a */
+#define PNG_INFO_iCCP 0x1000U  /* ESR, 1.0.6 */
+#define PNG_INFO_sPLT 0x2000U  /* ESR, 1.0.6 */
+#define PNG_INFO_sCAL 0x4000U  /* ESR, 1.0.6 */
+#define PNG_INFO_IDAT 0x8000U  /* ESR, 1.0.6 */
+#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
+
+/* This is used for the transformation routines, as some of them
+ * change these values for the row.  It also should enable using
+ * the routines for other purposes.
+ */
+typedef struct png_row_info_struct
+{
+   png_uint_32 width;    /* width of row */
+   png_size_t rowbytes;  /* number of bytes in row */
+   png_byte color_type;  /* color type of row */
+   png_byte bit_depth;   /* bit depth of row */
+   png_byte channels;    /* number of channels (1, 2, 3, or 4) */
+   png_byte pixel_depth; /* bits per pixel (depth * channels) */
+} png_row_info;
+
+typedef png_row_info * png_row_infop;
+typedef png_row_info * * png_row_infopp;
+
+/* These are the function types for the I/O functions and for the functions
+ * that allow the user to override the default I/O functions with his or her
+ * own.  The png_error_ptr type should match that of user-supplied warning
+ * and error functions, while the png_rw_ptr type should match that of the
+ * user read/write data functions.  Note that the 'write' function must not
+ * modify the buffer it is passed. The 'read' function, on the other hand, is
+ * expected to return the read data in the buffer.
+ */
+typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
+typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
+typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
+typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
+    int));
+typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
+    int));
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
+typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
+
+/* The following callback receives png_uint_32 row_number, int pass for the
+ * png_bytep data of the row.  When transforming an interlaced image the
+ * row number is the row number within the sub-image of the interlace pass, so
+ * the value will increase to the height of the sub-image (not the full image)
+ * then reset to 0 for the next pass.
+ *
+ * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+ * find the output pixel (x,y) given an interlaced sub-image pixel
+ * (row,col,pass).  (See below for these macros.)
+ */
+typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
+    png_uint_32, int));
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
+    png_bytep));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
+    png_unknown_chunkp));
+#endif
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+/* not used anywhere */
+/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This must match the function definition in <setjmp.h>, and the application
+ * must include this before png.h to obtain the definition of jmp_buf.  The
+ * function is required to be PNG_NORETURN, but this is not checked.  If the
+ * function does return the application will crash via an abort() or similar
+ * system level call.
+ *
+ * If you get a warning here while building the library you may need to make
+ * changes to ensure that pnglibconf.h records the calling convention used by
+ * your compiler.  This may be very difficult - try using a different compiler
+ * to build the library!
+ */
+PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
+#endif
+
+/* Transform masks for the high-level interface */
+#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
+#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
+#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
+#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
+#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
+#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
+#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
+#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
+#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
+#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
+#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
+#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
+#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only */
+/* Added to libpng-1.2.34 */
+#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
+#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
+/* Added to libpng-1.4.0 */
+#define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
+/* Added to libpng-1.5.4 */
+#define PNG_TRANSFORM_EXPAND_16     0x4000      /* read only */
+#if INT_MAX >= 0x8000 /* else this might break */
+#define PNG_TRANSFORM_SCALE_16      0x8000      /* read only */
+#endif
+
+/* Flags for MNG supported features */
+#define PNG_FLAG_MNG_EMPTY_PLTE     0x01
+#define PNG_FLAG_MNG_FILTER_64      0x04
+#define PNG_ALL_MNG_FEATURES        0x05
+
+/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
+ * this allowed the zlib default functions to be used on Windows
+ * platforms.  In 1.5 the zlib default malloc (which just calls malloc and
+ * ignores the first argument) should be completely compatible with the
+ * following.
+ */
+typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
+    png_alloc_size_t));
+typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
+
+/* Section 4: exported functions
+ * Here are the function definitions most commonly used.  This is not
+ * the place to find out how to use libpng.  See libpng-manual.txt for the
+ * full explanation, see example.c for the summary.  This just provides
+ * a simple one line description of the use of each function.
+ *
+ * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
+ * pngconf.h and in the *.dfn files in the scripts directory.
+ *
+ *   PNG_EXPORT(ordinal, type, name, (args));
+ *
+ *       ordinal:    ordinal that is used while building
+ *                   *.def files. The ordinal value is only
+ *                   relevant when preprocessing png.h with
+ *                   the *.dfn files for building symbol table
+ *                   entries, and are removed by pngconf.h.
+ *       type:       return type of the function
+ *       name:       function name
+ *       args:       function arguments, with types
+ *
+ * When we wish to append attributes to a function prototype we use
+ * the PNG_EXPORTA() macro instead.
+ *
+ *   PNG_EXPORTA(ordinal, type, name, (args), attributes);
+ *
+ *       ordinal, type, name, and args: same as in PNG_EXPORT().
+ *       attributes: function attributes
+ */
+
+/* Returns the version number of the library */
+PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
+
+/* Tell lib we have already handled the first <num_bytes> magic bytes.
+ * Handling more than 8 bytes from the beginning of the file is an error.
+ */
+PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
+
+/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
+ * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
+ * signature, and non-zero otherwise.  Having num_to_check == 0 or
+ * start > 7 will always fail (ie return non-zero).
+ */
+PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
+    png_size_t num_to_check));
+
+/* Simple signature checking function.  This is the same as calling
+ * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
+ */
+#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
+
+/* Allocate and initialize png_ptr struct for reading, and any other memory. */
+PNG_EXPORTA(4, png_structp, png_create_read_struct,
+    (png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn),
+    PNG_ALLOCATED);
+
+/* Allocate and initialize png_ptr struct for writing, and any other memory */
+PNG_EXPORTA(5, png_structp, png_create_write_struct,
+    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn),
+    PNG_ALLOCATED);
+
+PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
+    (png_const_structrp png_ptr));
+
+PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
+    png_size_t size));
+
+/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
+ * match up.
+ */
+#ifdef PNG_SETJMP_SUPPORTED
+/* This function returns the jmp_buf built in to *png_ptr.  It must be
+ * supplied with an appropriate 'longjmp' function to use on that jmp_buf
+ * unless the default error function is overridden in which case NULL is
+ * acceptable.  The size of the jmp_buf is checked against the actual size
+ * allocated by the library - the call will return NULL on a mismatch
+ * indicating an ABI mismatch.
+ */
+PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
+    png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
+#  define png_jmpbuf(png_ptr) \
+      (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
+#else
+#  define png_jmpbuf(png_ptr) \
+      (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
+#endif
+/* This function should be used by libpng applications in place of
+ * longjmp(png_ptr->jmpbuf, val).  If longjmp_fn() has been set, it
+ * will use it; otherwise it will call PNG_ABORT().  This function was
+ * added in libpng-1.5.0.
+ */
+PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
+    PNG_NORETURN);
+
+#ifdef PNG_READ_SUPPORTED
+/* Reset the compression stream */
+PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
+#endif
+
+/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
+    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn,
+    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+    PNG_ALLOCATED);
+PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
+    (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn,
+    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+    PNG_ALLOCATED);
+#endif
+
+/* Write the PNG file signature. */
+PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
+
+/* Write a PNG chunk - size, type, (optional) data, CRC. */
+PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
+    chunk_name, png_const_bytep data, png_size_t length));
+
+/* Write the start of a PNG chunk - length and chunk name. */
+PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
+    png_const_bytep chunk_name, png_uint_32 length));
+
+/* Write the data of a PNG chunk started with png_write_chunk_start(). */
+PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
+    png_const_bytep data, png_size_t length));
+
+/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
+PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
+
+/* Allocate and initialize the info structure */
+PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
+    PNG_ALLOCATED);
+
+/* DEPRECATED: this function allowed init structures to be created using the
+ * default allocation method (typically malloc).  Use is deprecated in 1.6.0 and
+ * the API will be removed in the future.
+ */
+PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
+    png_size_t png_info_struct_size), PNG_DEPRECATED);
+
+/* Writes all the PNG information before the image. */
+PNG_EXPORT(20, void, png_write_info_before_PLTE,
+    (png_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(21, void, png_write_info,
+    (png_structrp png_ptr, png_const_inforp info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data. */
+PNG_EXPORT(22, void, png_read_info,
+    (png_structrp png_ptr, png_inforp info_ptr));
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+   /* Convert to a US string format: there is no localization support in this
+    * routine.  The original implementation used a 29 character buffer in
+    * png_struct, this will be removed in future versions.
+    */
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
+PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
+    png_const_timep ptime),PNG_DEPRECATED);
+#endif
+PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
+    png_const_timep ptime));
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* Convert from a struct tm to png_time */
+PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
+    const struct tm * ttime));
+
+/* Convert from time_t to png_time.  Uses gmtime() */
+PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
+#endif /* CONVERT_tIME */
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
+PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
+PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
+PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
+PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
+ * of a tRNS chunk if present.
+ */
+PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Use blue, green, red order for pixels. */
+PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand the grayscale to 24-bit RGB if necessary. */
+PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB to grayscale. */
+#define PNG_ERROR_ACTION_NONE  1
+#define PNG_ERROR_ACTION_WARN  2
+#define PNG_ERROR_ACTION_ERROR 3
+#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
+
+PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
+    int error_action, double red, double green))
+PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
+    int error_action, png_fixed_point red, png_fixed_point green))
+
+PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
+    png_ptr));
+#endif
+
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
+    png_colorp palette));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* How the alpha channel is interpreted - this affects how the color channels
+ * of a PNG file are returned to the calling application when an alpha channel,
+ * or a tRNS chunk in a palette file, is present.
+ *
+ * This has no effect on the way pixels are written into a PNG output
+ * datastream. The color samples in a PNG datastream are never premultiplied
+ * with the alpha samples.
+ *
+ * The default is to return data according to the PNG specification: the alpha
+ * channel is a linear measure of the contribution of the pixel to the
+ * corresponding composited pixel, and the color channels are unassociated
+ * (not premultiplied).  The gamma encoded color channels must be scaled
+ * according to the contribution and to do this it is necessary to undo
+ * the encoding, scale the color values, perform the composition and reencode
+ * the values.  This is the 'PNG' mode.
+ *
+ * The alternative is to 'associate' the alpha with the color information by
+ * storing color channel values that have been scaled by the alpha.
+ * image.  These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
+ * (the latter being the two common names for associated alpha color channels).
+ *
+ * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
+ * value is equal to the maximum value.
+ *
+ * The final choice is to gamma encode the alpha channel as well.  This is
+ * broken because, in practice, no implementation that uses this choice
+ * correctly undoes the encoding before handling alpha composition.  Use this
+ * choice only if other serious errors in the software or hardware you use
+ * mandate it; the typical serious error is for dark halos to appear around
+ * opaque areas of the composited PNG image because of arithmetic overflow.
+ *
+ * The API function png_set_alpha_mode specifies which of these choices to use
+ * with an enumerated 'mode' value and the gamma of the required output:
+ */
+#define PNG_ALPHA_PNG           0 /* according to the PNG standard */
+#define PNG_ALPHA_STANDARD      1 /* according to Porter/Duff */
+#define PNG_ALPHA_ASSOCIATED    1 /* as above; this is the normal practice */
+#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+#define PNG_ALPHA_OPTIMIZED     2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+#define PNG_ALPHA_BROKEN        3 /* the alpha channel is gamma encoded */
+
+PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
+    double output_gamma))
+PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
+    int mode, png_fixed_point output_gamma))
+#endif
+
+#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* The output_gamma value is a screen gamma in libpng terminology: it expresses
+ * how to decode the output values, not how they are encoded.
+ */
+#define PNG_DEFAULT_sRGB -1       /* sRGB gamma and color space */
+#define PNG_GAMMA_MAC_18 -2       /* Old Mac '1.8' gamma and color space */
+#define PNG_GAMMA_sRGB   220000   /* Television standards--matches sRGB gamma */
+#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
+#endif
+
+/* The following are examples of calls to png_set_alpha_mode to achieve the
+ * required overall gamma correction and, where necessary, alpha
+ * premultiplication.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ *    This is the default libpng handling of the alpha channel - it is not
+ *    pre-multiplied into the color components.  In addition the call states
+ *    that the output is for a sRGB system and causes all PNG files without gAMA
+ *    chunks to be assumed to be encoded using sRGB.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    In this case the output is assumed to be something like an sRGB conformant
+ *    display preceeded by a power-law lookup table of power 1.45.  This is how
+ *    early Mac systems behaved.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+ *    This is the classic Jim Blinn approach and will work in academic
+ *    environments where everything is done by the book.  It has the shortcoming
+ *    of assuming that input PNG data with no gamma information is linear - this
+ *    is unlikely to be correct unless the PNG files where generated locally.
+ *    Most of the time the output precision will be so low as to show
+ *    significant banding in dark areas of the image.
+ *
+ * png_set_expand_16(pp);
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+ *    This is a somewhat more realistic Jim Blinn inspired approach.  PNG files
+ *    are assumed to have the sRGB encoding if not marked with a gamma value and
+ *    the output is always 16 bits per component.  This permits accurate scaling
+ *    and processing of the data.  If you know that your input PNG files were
+ *    generated locally you might need to replace PNG_DEFAULT_sRGB with the
+ *    correct value for your system.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+ *    If you just need to composite the PNG image onto an existing background
+ *    and if you control the code that does this you can use the optimization
+ *    setting.  In this case you just copy completely opaque pixels to the
+ *    output.  For pixels that are not completely transparent (you just skip
+ *    those) you do the composition math using png_composite or png_composite_16
+ *    below then encode the resultant 8-bit or 16-bit values to match the output
+ *    encoding.
+ *
+ * Other cases
+ *    If neither the PNG nor the standard linear encoding work for you because
+ *    of the software or hardware you use then you have a big problem.  The PNG
+ *    case will probably result in halos around the image.  The linear encoding
+ *    will probably result in a washed out, too bright, image (it's actually too
+ *    contrasty.)  Try the ALPHA_OPTIMIZED mode above - this will probably
+ *    substantially reduce the halos.  Alternatively try:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+ *    This option will also reduce the halos, but there will be slight dark
+ *    halos round the opaque parts of the image where the background is light.
+ *    In the OPTIMIZED mode the halos will be light halos where the background
+ *    is dark.  Take your pick - the halos are unavoidable unless you can get
+ *    your hardware/software fixed!  (The OPTIMIZED approach is slightly
+ *    faster.)
+ *
+ * When the default gamma of PNG files doesn't match the output gamma.
+ *    If you have PNG files with no gamma information png_set_alpha_mode allows
+ *    you to provide a default gamma, but it also sets the ouput gamma to the
+ *    matching value.  If you know your PNG files have a gamma that doesn't
+ *    match the output you can take advantage of the fact that
+ *    png_set_alpha_mode always sets the output gamma but only sets the PNG
+ *    default if it is not already set:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    The first call sets both the default and the output gamma values, the
+ *    second call overrides the output gamma without changing the default.  This
+ *    is easier than achieving the same effect with png_set_gamma.  You must use
+ *    PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+ *    fire if more than one call to png_set_alpha_mode and png_set_background is
+ *    made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+ *    are ignored.
+ */
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
+PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
+    int flags));
+/* The values of the PNG_FILLER_ defines should NOT be changed */
+#  define PNG_FILLER_BEFORE 0
+#  define PNG_FILLER_AFTER 1
+/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
+PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
+    png_uint_32 filler, int flags));
+#endif /* READ_FILLER || WRITE_FILLER */
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swap bytes in 16-bit depth files. */
+PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
+PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Swap packing order of pixels in bytes. */
+PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+/* Converts files to legal bit depths. */
+PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
+    true_bits));
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+    defined(PNG_WRITE_INTERLACING_SUPPORTED)
+/* Have the code handle the interlacing.  Returns the number of passes.
+ * MUST be called before png_read_update_info or png_start_read_image,
+ * otherwise it will not have the desired effect.  Note that it is still
+ * necessary to call png_read_row or png_read_rows png_get_image_height
+ * times for each pass.
+*/
+PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+/* Invert monochrome files */
+PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS by replacing with a background color.  Prior to
+ * libpng-1.5.4 this API must not be called before the PNG file header has been
+ * read.  Doing so will result in unexpected behavior and possible warnings or
+ * errors if the PNG file contains a bKGD chunk.
+ */
+PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, double background_gamma))
+PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, png_fixed_point background_gamma))
+#endif
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+#  define PNG_BACKGROUND_GAMMA_UNKNOWN 0
+#  define PNG_BACKGROUND_GAMMA_SCREEN  1
+#  define PNG_BACKGROUND_GAMMA_FILE    2
+#  define PNG_BACKGROUND_GAMMA_UNIQUE  3
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale a 16-bit depth file down to 8-bit, accurately. */
+PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
+/* Strip the second byte of information from a 16-bit depth file. */
+PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Turn on quantizing, and reduce the palette to the number of colors
+ * available.
+ */
+PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
+    png_colorp palette, int num_palette, int maximum_colors,
+    png_const_uint_16p histogram, int full_quantize));
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* The threshold on gamma processing is configurable but hard-wired into the
+ * library.  The following is the floating point variant.
+ */
+#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
+
+/* Handle gamma correction. Screen_gamma=(display_exponent).
+ * NOTE: this API simply sets the screen and file gamma values. It will
+ * therefore override the value for gamma in a PNG file if it is called after
+ * the file header has been read - use with care  - call before reading the PNG
+ * file for best results!
+ *
+ * These routines accept the same gamma values as png_set_alpha_mode (described
+ * above).  The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
+ * API (floating point or fixed.)  Notice, however, that the 'file_gamma' value
+ * is the inverse of a 'screen gamma' value.
+ */
+PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
+    double screen_gamma, double override_file_gamma))
+PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
+    png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set how many lines between output flushes - 0 for no flushing */
+PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
+/* Flush the current PNG output buffer */
+PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
+#endif
+
+/* Optional update palette with requested transformations */
+PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
+
+/* Optional call to update the users info structure */
+PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
+    png_inforp info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data. */
+PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
+    png_bytepp display_row, png_uint_32 num_rows));
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read a row of data. */
+PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
+    png_bytep display_row));
+#endif
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the whole image into memory at once. */
+PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
+#endif
+
+/* Write a row of image data */
+PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
+    png_const_bytep row));
+
+/* Write a few rows of image data: (*row) is not written; however, the type
+ * is declared as writeable to maintain compatibility with previous versions
+ * of libpng and to allow the 'display_row' array from read_rows to be passed
+ * unchanged to write_rows.
+ */
+PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
+    png_uint_32 num_rows));
+
+/* Write the image data */
+PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
+
+/* Write the end of the PNG file. */
+PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
+    png_inforp info_ptr));
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file. */
+PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
+#endif
+
+/* Free any memory associated with the png_info_struct */
+PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
+    png_infopp info_ptr_ptr));
+
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
+    png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
+
+/* Free any memory associated with the png_struct and the png_info_structs */
+PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
+    png_infopp info_ptr_ptr));
+
+/* Set the libpng method of handling chunk CRC errors */
+PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
+    int ancil_action));
+
+/* Values for png_set_crc_action() say how to handle CRC errors in
+ * ancillary and critical chunks, and whether to use the data contained
+ * therein.  Note that it is impossible to "discard" data in a critical
+ * chunk.  For versions prior to 0.90, the action was always error/quit,
+ * whereas in version 0.90 and later, the action for CRC errors in ancillary
+ * chunks is warn/discard.  These values should NOT be changed.
+ *
+ *      value                       action:critical     action:ancillary
+ */
+#define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
+#define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
+#define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
+#define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
+#define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
+#define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
+
+#ifdef PNG_WRITE_SUPPORTED
+/* These functions give the user control over the scan-line filtering in
+ * libpng and the compression methods used by zlib.  These functions are
+ * mainly useful for testing, as the defaults should work with most users.
+ * Those users who are tight on memory or want faster performance at the
+ * expense of compression can modify them.  See the compression library
+ * header file (zlib.h) for an explination of the compression functions.
+ */
+
+/* Set the filtering method(s) used by libpng.  Currently, the only valid
+ * value for "method" is 0.
+ */
+PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
+    int filters));
+#endif /* WRITE */
+
+/* Flags for png_set_filter() to say which filters to use.  The flags
+ * are chosen so that they don't conflict with real filter types
+ * below, in case they are supplied instead of the #defined constants.
+ * These values should NOT be changed.
+ */
+#define PNG_NO_FILTERS     0x00
+#define PNG_FILTER_NONE    0x08
+#define PNG_FILTER_SUB     0x10
+#define PNG_FILTER_UP      0x20
+#define PNG_FILTER_AVG     0x40
+#define PNG_FILTER_PAETH   0x80
+#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
+#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
+
+/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
+ * These defines should NOT be changed.
+ */
+#define PNG_FILTER_VALUE_NONE  0
+#define PNG_FILTER_VALUE_SUB   1
+#define PNG_FILTER_VALUE_UP    2
+#define PNG_FILTER_VALUE_AVG   3
+#define PNG_FILTER_VALUE_PAETH 4
+#define PNG_FILTER_VALUE_LAST  5
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
+PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
+    int heuristic_method, int num_weights, png_const_doublep filter_weights,
+    png_const_doublep filter_costs))
+PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
+    (png_structrp png_ptr, int heuristic_method, int num_weights,
+    png_const_fixed_point_p filter_weights,
+    png_const_fixed_point_p filter_costs))
+#endif /* WRITE_WEIGHTED_FILTER */
+
+/* The following are no longer used and will be removed from libpng-1.7: */
+#define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
+#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
+#define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
+#define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
+
+/* Set the library compression level.  Currently, valid values range from
+ * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
+ * (0 - no compression, 9 - "maximal" compression).  Note that tests have
+ * shown that zlib compression levels 3-6 usually perform as well as level 9
+ * for PNG images, and do considerably fewer caclulations.  In the future,
+ * these values may not correspond directly to the zlib compression levels.
+ */
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
+    int level));
+
+PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
+    int mem_level));
+
+PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
+    int strategy));
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
+    int window_bits));
+
+PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
+    int method));
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
+
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+/* Also set zlib parameters for compressing non-IDAT chunks */
+PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
+    int level));
+
+PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
+    int mem_level));
+
+PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
+    int strategy));
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(225, void, png_set_text_compression_window_bits,
+    (png_structrp png_ptr, int window_bits));
+
+PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
+    int method));
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+#endif /* WRITE */
+
+/* These next functions are called for input/output, memory, and error
+ * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
+ * and call standard C I/O routines such as fread(), fwrite(), and
+ * fprintf().  These functions can be made to use other I/O routines
+ * at run time for those applications that need to handle I/O in a
+ * different manner by calling png_set_???_fn().  See libpng-manual.txt for
+ * more information.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+/* Initialize the input/output for the PNG file to the default functions. */
+PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
+#endif
+
+/* Replace the (error and abort), and warning functions with user
+ * supplied functions.  If no messages are to be printed you must still
+ * write and use replacement functions. The replacement error_fn should
+ * still do a longjmp to the last setjmp location if you are using this
+ * method of error handling.  If error_fn or warning_fn is NULL, the
+ * default function will be used.
+ */
+
+PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
+    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
+
+/* Return the user pointer associated with the error functions */
+PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
+
+/* Replace the default data output functions with a user supplied one(s).
+ * If buffered output is not used, then output_flush_fn can be set to NULL.
+ * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
+ * output_flush_fn will be ignored (and thus can be NULL).
+ * It is probably a mistake to use NULL for output_flush_fn if
+ * write_data_fn is not also NULL unless you have built libpng with
+ * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
+ * default flush function, which uses the standard *FILE structure, will
+ * be used.
+ */
+PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
+    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
+
+/* Replace the default data input function with a user supplied one. */
+PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
+    png_rw_ptr read_data_fn));
+
+/* Return the user pointer associated with the I/O functions */
+PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
+
+PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
+    png_read_status_ptr read_row_fn));
+
+PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
+    png_write_status_ptr write_row_fn));
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* Replace the default memory allocation functions with user supplied one(s). */
+PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+/* Return the user pointer associated with the memory functions */
+PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
+    png_user_transform_ptr read_user_transform_fn));
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
+    png_user_transform_ptr write_user_transform_fn));
+#endif
+
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
+    png_voidp user_transform_ptr, int user_transform_depth,
+    int user_transform_channels));
+/* Return the user pointer associated with the user transform functions */
+PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
+    (png_const_structrp png_ptr));
+#endif
+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+/* Return information about the row currently being processed.  Note that these
+ * APIs do not fail but will return unexpected results if called outside a user
+ * transform callback.  Also note that when transforming an interlaced image the
+ * row number is the row number within the sub-image of the interlace pass, so
+ * the value will increase to the height of the sub-image (not the full image)
+ * then reset to 0 for the next pass.
+ *
+ * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+ * find the output pixel (x,y) given an interlaced sub-image pixel
+ * (row,col,pass).  (See below for these macros.)
+ */
+PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
+PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+/* This callback is called only for *unknown* chunks.  If
+ * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
+ * chunks to be treated as unknown, however in this case the callback must do
+ * any processing required by the chunk (e.g. by calling the appropriate
+ * png_set_ APIs.)
+ *
+ * There is no write support - on write, by default, all the chunks in the
+ * 'unknown' list are written in the specified position.
+ *
+ * The integer return from the callback function is interpreted thus:
+ *
+ * negative: An error occurred; png_chunk_error will be called.
+ *     zero: The chunk was not handled, the chunk will be saved. A critical
+ *           chunk will cause an error at this point unless it is to be saved.
+ * positive: The chunk was handled, libpng will ignore/discard it.
+ *
+ * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
+ * how this behavior will change in libpng 1.7
+ */
+PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
+    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+/* Sets the function callbacks for the push reader, and a pointer to a
+ * user-defined structure available to the callback functions.
+ */
+PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
+    png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
+    png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
+
+/* Returns the user pointer associated with the push read functions */
+PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
+    (png_const_structrp png_ptr));
+
+/* Function to be called when data becomes available */
+PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
+    png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
+
+/* A function which may be called *only* within png_process_data to stop the
+ * processing of any more data.  The function returns the number of bytes
+ * remaining, excluding any that libpng has cached internally.  A subsequent
+ * call to png_process_data must supply these bytes again.  If the argument
+ * 'save' is set to true the routine will first save all the pending data and
+ * will always return 0.
+ */
+PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structrp, int save));
+
+/* A function which may be called *only* outside (after) a call to
+ * png_process_data.  It returns the number of bytes of data to skip in the
+ * input.  Normally it will return 0, but if it returns a non-zero value the
+ * application must skip than number of bytes of input data and pass the
+ * following data to the next call to png_process_data.
+ */
+PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
+
+/* Function that combines rows.  'new_row' is a flag that should come from
+ * the callback and be non-NULL if anything needs to be done; the library
+ * stores its own version of the new data internally and ignores the passed
+ * in value.
+ */
+PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
+    png_bytep old_row, png_const_bytep new_row));
+#endif /* PROGRESSIVE_READ */
+
+PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
+    png_alloc_size_t size), PNG_ALLOCATED);
+/* Added at libpng version 1.4.0 */
+PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
+    png_alloc_size_t size), PNG_ALLOCATED);
+
+/* Added at libpng version 1.2.4 */
+PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
+    png_alloc_size_t size), PNG_ALLOCATED);
+
+/* Frees a pointer allocated by png_malloc() */
+PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
+
+/* Free data that was allocated internally */
+PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 free_me, int num));
+
+/* Reassign responsibility for freeing existing data, whether allocated
+ * by libpng or by the application; this works on the png_info structure passed
+ * in, it does not change the state for other png_info structures.
+ *
+ * It is unlikely that this function works correctly as of 1.6.0 and using it
+ * may result either in memory leaks or double free of allocated data.
+ */
+PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int freer, png_uint_32 mask));
+
+/* Assignments for png_data_freer */
+#define PNG_DESTROY_WILL_FREE_DATA 1
+#define PNG_SET_WILL_FREE_DATA 1
+#define PNG_USER_WILL_FREE_DATA 2
+/* Flags for png_ptr->free_me and info_ptr->free_me */
+#define PNG_FREE_HIST 0x0008U
+#define PNG_FREE_ICCP 0x0010U
+#define PNG_FREE_SPLT 0x0020U
+#define PNG_FREE_ROWS 0x0040U
+#define PNG_FREE_PCAL 0x0080U
+#define PNG_FREE_SCAL 0x0100U
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#  define PNG_FREE_UNKN 0x0200U
+#endif
+/*      PNG_FREE_LIST 0x0400U   removed in 1.6.0 because it is ignored */
+#define PNG_FREE_PLTE 0x1000U
+#define PNG_FREE_TRNS 0x2000U
+#define PNG_FREE_TEXT 0x4000U
+#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
+#define PNG_FREE_ALL  0xffffU
+#define PNG_FREE_MUL  0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
+    png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
+PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
+    png_voidp ptr), PNG_DEPRECATED);
+#endif
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
+    png_const_charp error_message), PNG_NORETURN);
+
+/* The same, but the chunk name is prepended to the error string. */
+PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
+    png_const_charp error_message), PNG_NORETURN);
+
+#else
+/* Fatal error in PNG image of libpng - can't continue */
+PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
+#  define png_error(s1,s2) png_err(s1)
+#  define png_chunk_error(s1,s2) png_err(s1)
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* Non-fatal error in libpng.  Can continue, but may have a problem. */
+PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
+    png_const_charp warning_message));
+
+/* Non-fatal error in libpng, chunk name is prepended to message. */
+PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
+    png_const_charp warning_message));
+#else
+#  define png_warning(s1,s2) ((void)(s1))
+#  define png_chunk_warning(s1,s2) ((void)(s1))
+#endif
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Benign error in libpng.  Can continue, but may have a problem.
+ * User can choose whether to handle as a fatal error or as a warning. */
+PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
+    png_const_charp warning_message));
+
+#ifdef PNG_READ_SUPPORTED
+/* Same, chunk name is prepended to message (only during read) */
+PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
+    png_const_charp warning_message));
+#endif
+
+PNG_EXPORT(109, void, png_set_benign_errors,
+    (png_structrp png_ptr, int allowed));
+#else
+#  ifdef PNG_ALLOW_BENIGN_ERRORS
+#    define png_benign_error png_warning
+#    define png_chunk_benign_error png_chunk_warning
+#  else
+#    define png_benign_error png_error
+#    define png_chunk_benign_error png_chunk_error
+#  endif
+#endif
+
+/* The png_set_<chunk> functions are for storing values in the png_info_struct.
+ * Similarly, the png_get_<chunk> calls are used to read values from the
+ * png_info_struct, either storing the parameters in the passed variables, or
+ * setting pointers into the png_info_struct where the data is stored.  The
+ * png_get_<chunk> functions return a non-zero value if the data was available
+ * in info_ptr, or return zero and do not change any of the parameters if the
+ * data was not available.
+ *
+ * These functions should be used instead of directly accessing png_info
+ * to avoid problems with future changes in the size and internal layout of
+ * png_info_struct.
+ */
+/* Returns "flag" if chunk data is valid in info_ptr. */
+PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_uint_32 flag));
+
+/* Returns number of bytes needed to hold a transformed row. */
+PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* Returns row_pointers, which is an array of pointers to scanlines that was
+ * returned from png_read_png().
+ */
+PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Set row_pointers, which is an array of pointers to scanlines for use
+ * by png_write_png().
+ */
+PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_bytepp row_pointers));
+#endif
+
+/* Returns number of color channels in image. */
+PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Returns image width in pixels. */
+PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image height in pixels. */
+PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image bit_depth. */
+PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image color_type. */
+PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image filter_type. */
+PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image interlace_type. */
+PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image compression_type. */
+PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+
+/* Returns image resolution in pixels per meter, from pHYs chunk data. */
+PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+/* Returns pixel aspect ratio, computed from pHYs chunk data.  */
+PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr))
+PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr))
+
+/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
+PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+#endif /* EASY_ACCESS */
+
+#ifdef PNG_READ_SUPPORTED
+/* Returns pointer to signature string read from PNG header */
+PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr));
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_color_16p *background));
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_color_16p background));
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
+    double *red_y, double *green_x, double *green_y, double *blue_x,
+    double *blue_y))
+PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
+    double *green_X, double *green_Y, double *green_Z, double *blue_X,
+    double *blue_Y, double *blue_Z))
+PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_white_x, png_fixed_point *int_white_y,
+    png_fixed_point *int_red_x, png_fixed_point *int_red_y,
+    png_fixed_point *int_green_x, png_fixed_point *int_green_y,
+    png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
+PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z))
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
+    png_inforp info_ptr,
+    double white_x, double white_y, double red_x, double red_y, double green_x,
+    double green_y, double blue_x, double blue_y))
+PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
+    png_inforp info_ptr, double red_X, double red_Y, double red_Z,
+    double green_X, double green_Y, double green_Z, double blue_X,
+    double blue_Y, double blue_Z))
+PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_fixed_point int_white_x,
+    png_fixed_point int_white_y, png_fixed_point int_red_x,
+    png_fixed_point int_red_y, png_fixed_point int_green_x,
+    png_fixed_point int_green_y, png_fixed_point int_blue_x,
+    png_fixed_point int_blue_y))
+PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
+    png_fixed_point int_red_Z, png_fixed_point int_green_X,
+    png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+    png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+    png_fixed_point int_blue_Z))
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_bytep *exif));
+PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
+    png_inforp info_ptr, const png_bytep exif));
+
+PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
+PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
+    png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif));
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, double *file_gamma))
+PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_file_gamma))
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
+    png_inforp info_ptr, double file_gamma))
+PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_fixed_point int_file_gamma))
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_uint_16p *hist));
+PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_uint_16p hist));
+#endif
+
+PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
+    int *bit_depth, int *color_type, int *interlace_method,
+    int *compression_method, int *filter_method));
+
+PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_method, int compression_method,
+    int filter_method));
+
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
+   png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
+   int *unit_type));
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
+    int unit_type));
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
+    png_int_32 *X1, int *type, int *nparams, png_charp *units,
+    png_charpp *params));
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
+    int type, int nparams, png_const_charp units, png_charpp params));
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
+    int *unit_type));
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
+#endif
+
+PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
+   png_inforp info_ptr, png_colorp *palette, int *num_palette));
+
+PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
+    png_inforp info_ptr, png_const_colorp palette, int num_palette));
+
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_color_8p *sig_bit));
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_color_8p sig_bit));
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, int *file_srgb_intent));
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int srgb_intent));
+PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int srgb_intent));
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_charpp name, int *compression_type,
+    png_bytepp profile, png_uint_32 *proflen));
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_charp name, int compression_type,
+    png_const_bytep profile, png_uint_32 proflen));
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_sPLT_tpp entries));
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+/* png_get_text also returns the number of text chunks in *num_text */
+PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_textp *text_ptr, int *num_text));
+#endif
+
+/* Note while png_set_text() will accept a structure whose text,
+ * language, and  translated keywords are NULL pointers, the structure
+ * returned by png_get_text will always contain regular
+ * zero-terminated C strings.  They might be empty strings but
+ * they will never be NULL pointers.
+ */
+
+#ifdef PNG_TEXT_SUPPORTED
+PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_textp text_ptr, int num_text));
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_timep *mod_time));
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_timep mod_time));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
+    png_color_16p *trans_color));
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
+    png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
+    png_const_color_16p trans_color));
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, int *unit, double *width, double *height))
+#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+   defined(PNG_FLOATING_POINT_SUPPORTED)
+/* NOTE: this API is currently implemented using floating point arithmetic,
+ * consequently it can only be used on systems with floating point support.
+ * In any case the range of values supported by png_fixed_point is small and it
+ * is highly recommended that png_get_sCAL_s be used instead.
+ */
+PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
+    png_fixed_point *width, png_fixed_point *height))
+#endif
+PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
+    png_charpp swidth, png_charpp sheight));
+
+PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int unit, double width, double height))
+PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
+   png_inforp info_ptr, int unit, png_fixed_point width,
+   png_fixed_point height))
+PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int unit,
+    png_const_charp swidth, png_const_charp sheight));
+#endif /* sCAL */
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+/* Provide the default handling for all unknown chunks or, optionally, for
+ * specific unknown chunks.
+ *
+ * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
+ * ignored and the default was used, the per-chunk setting only had an effect on
+ * write.  If you wish to have chunk-specific handling on read in code that must
+ * work on earlier versions you must use a user chunk callback to specify the
+ * desired handling (keep or discard.)
+ *
+ * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below.  The
+ * parameter is interpreted as follows:
+ *
+ * READ:
+ *    PNG_HANDLE_CHUNK_AS_DEFAULT:
+ *       Known chunks: do normal libpng processing, do not keep the chunk (but
+ *          see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+ *       Unknown chunks: for a specific chunk use the global default, when used
+ *          as the default discard the chunk data.
+ *    PNG_HANDLE_CHUNK_NEVER:
+ *       Discard the chunk data.
+ *    PNG_HANDLE_CHUNK_IF_SAFE:
+ *       Keep the chunk data if the chunk is not critical else raise a chunk
+ *       error.
+ *    PNG_HANDLE_CHUNK_ALWAYS:
+ *       Keep the chunk data.
+ *
+ * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
+ * below.  Notice that specifying "AS_DEFAULT" as a global default is equivalent
+ * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
+ * it simply resets the behavior to the libpng default.
+ *
+ * INTERACTION WTIH USER CHUNK CALLBACKS:
+ * The per-chunk handling is always used when there is a png_user_chunk_ptr
+ * callback and the callback returns 0; the chunk is then always stored *unless*
+ * it is critical and the per-chunk setting is other than ALWAYS.  Notice that
+ * the global default is *not* used in this case.  (In effect the per-chunk
+ * value is incremented to at least IF_SAFE.)
+ *
+ * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
+ * per-chunk defaults will be honored.  If you want to preserve the current
+ * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
+ * as the default - if you don't do this libpng 1.6 will issue a warning.
+ *
+ * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
+ * earlier simply return '1' (handled).
+ *
+ * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
+ *    If this is *not* set known chunks will always be handled by libpng and
+ *    will never be stored in the unknown chunk list.  Known chunks listed to
+ *    png_set_keep_unknown_chunks will have no effect.  If it is set then known
+ *    chunks listed with a keep other than AS_DEFAULT will *never* be processed
+ *    by libpng, in addition critical chunks must either be processed by the
+ *    callback or saved.
+ *
+ *    The IHDR and IEND chunks must not be listed.  Because this turns off the
+ *    default handling for chunks that would otherwise be recognized the
+ *    behavior of libpng transformations may well become incorrect!
+ *
+ * WRITE:
+ *    When writing chunks the options only apply to the chunks specified by
+ *    png_set_unknown_chunks (below), libpng will *always* write known chunks
+ *    required by png_set_ calls and will always write the core critical chunks
+ *    (as required for PLTE).
+ *
+ *    Each chunk in the png_set_unknown_chunks list is looked up in the
+ *    png_set_keep_unknown_chunks list to find the keep setting, this is then
+ *    interpreted as follows:
+ *
+ *    PNG_HANDLE_CHUNK_AS_DEFAULT:
+ *       Write safe-to-copy chunks and write other chunks if the global
+ *       default is set to _ALWAYS, otherwise don't write this chunk.
+ *    PNG_HANDLE_CHUNK_NEVER:
+ *       Do not write the chunk.
+ *    PNG_HANDLE_CHUNK_IF_SAFE:
+ *       Write the chunk if it is safe-to-copy, otherwise do not write it.
+ *    PNG_HANDLE_CHUNK_ALWAYS:
+ *       Write the chunk.
+ *
+ * Note that the default behavior is effectively the opposite of the read case -
+ * in read unknown chunks are not stored by default, in write they are written
+ * by default.  Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
+ * - on write the safe-to-copy bit is checked, on read the critical bit is
+ * checked and on read if the chunk is critical an error will be raised.
+ *
+ * num_chunks:
+ * ===========
+ *    If num_chunks is positive, then the "keep" parameter specifies the manner
+ *    for handling only those chunks appearing in the chunk_list array,
+ *    otherwise the chunk list array is ignored.
+ *
+ *    If num_chunks is 0 the "keep" parameter specifies the default behavior for
+ *    unknown chunks, as described above.
+ *
+ *    If num_chunks is negative, then the "keep" parameter specifies the manner
+ *    for handling all unknown chunks plus all chunks recognized by libpng
+ *    except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
+ *    be processed by libpng.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
+    int keep, png_const_bytep chunk_list, int num_chunks));
+#endif /* HANDLE_AS_UNKNOWN */
+
+/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
+ * the result is therefore true (non-zero) if special handling is required,
+ * false for the default handling.
+ */
+PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
+    png_const_bytep chunk_name));
+#endif /* SET_UNKNOWN_CHUNKS */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_unknown_chunkp unknowns,
+    int num_unknowns));
+   /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
+    * unknowns to the location currently stored in the png_struct.  This is
+    * invariably the wrong value on write.  To fix this call the following API
+    * for each chunk in the list with the correct location.  If you know your
+    * code won't be compiled on earlier versions you can rely on
+    * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
+    * the correct thing.
+    */
+
+PNG_EXPORT(175, void, png_set_unknown_chunk_location,
+    (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
+
+PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_unknown_chunkpp entries));
+#endif
+
+/* Png_free_data() will turn off the "valid" flag for anything it frees.
+ * If you need to turn it off for a chunk that your application has freed,
+ * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
+ */
+PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
+    png_inforp info_ptr, int mask));
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+/* The "params" pointer is currently not used and is for future expansion. */
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
+    int transforms, png_voidp params));
+#endif
+#ifdef PNG_WRITE_SUPPORTED
+PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
+    int transforms, png_voidp params));
+#endif
+#endif
+
+PNG_EXPORT(180, png_const_charp, png_get_copyright,
+    (png_const_structrp png_ptr));
+PNG_EXPORT(181, png_const_charp, png_get_header_ver,
+    (png_const_structrp png_ptr));
+PNG_EXPORT(182, png_const_charp, png_get_header_version,
+    (png_const_structrp png_ptr));
+PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
+    (png_const_structrp png_ptr));
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
+    png_uint_32 mng_features_permitted));
+#endif
+
+/* For use in png_set_keep_unknown, added to version 1.2.6 */
+#define PNG_HANDLE_CHUNK_AS_DEFAULT   0
+#define PNG_HANDLE_CHUNK_NEVER        1
+#define PNG_HANDLE_CHUNK_IF_SAFE      2
+#define PNG_HANDLE_CHUNK_ALWAYS       3
+#define PNG_HANDLE_CHUNK_LAST         4
+
+/* Strip the prepended error numbers ("#nnn ") from error and warning
+ * messages before passing them to the error or warning handler.
+ */
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
+    png_uint_32 strip_mode));
+#endif
+
+/* Added in libpng-1.2.6 */
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
+    png_uint_32 user_width_max, png_uint_32 user_height_max));
+PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
+    (png_const_structrp png_ptr));
+PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
+    (png_const_structrp png_ptr));
+/* Added in libpng-1.4.0 */
+PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
+    png_uint_32 user_chunk_cache_max));
+PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
+    (png_const_structrp png_ptr));
+/* Added in libpng-1.4.1 */
+PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
+    png_alloc_size_t user_chunk_cache_max));
+PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
+    (png_const_structrp png_ptr));
+#endif
+
+#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr));
+
+PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr))
+#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
+PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr))
+#endif
+
+PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr))
+#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
+PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
+    (png_const_structrp png_ptr, png_const_inforp info_ptr))
+#endif
+
+#  ifdef PNG_pHYs_SUPPORTED
+PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
+    int *unit_type));
+#  endif /* pHYs */
+#endif  /* INCH_CONVERSIONS */
+
+/* Added in libpng-1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
+
+/* Removed from libpng 1.6; use png_get_io_chunk_type. */
+PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
+    PNG_DEPRECATED)
+
+PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
+    (png_const_structrp png_ptr));
+
+/* The flags returned by png_get_io_state() are the following: */
+#  define PNG_IO_NONE        0x0000   /* no I/O at this moment */
+#  define PNG_IO_READING     0x0001   /* currently reading */
+#  define PNG_IO_WRITING     0x0002   /* currently writing */
+#  define PNG_IO_SIGNATURE   0x0010   /* currently at the file signature */
+#  define PNG_IO_CHUNK_HDR   0x0020   /* currently at the chunk header */
+#  define PNG_IO_CHUNK_DATA  0x0040   /* currently at the chunk data */
+#  define PNG_IO_CHUNK_CRC   0x0080   /* currently at the chunk crc */
+#  define PNG_IO_MASK_OP     0x000f   /* current operation: reading/writing */
+#  define PNG_IO_MASK_LOC    0x00f0   /* current location: sig/hdr/data/crc */
+#endif /* IO_STATE */
+
+/* Interlace support.  The following macros are always defined so that if
+ * libpng interlace handling is turned off the macros may be used to handle
+ * interlaced images within the application.
+ */
+#define PNG_INTERLACE_ADAM7_PASSES 7
+
+/* Two macros to return the first row and first column of the original,
+ * full, image which appears in a given pass.  'pass' is in the range 0
+ * to 6 and the result is in the range 0 to 7.
+ */
+#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
+#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
+
+/* A macro to return the offset between pixels in the output row for a pair of
+ * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
+ * follows.  Note that ROW_OFFSET is the offset from one row to the next whereas
+ * COL_OFFSET is from one column to the next, within a row.
+ */
+#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
+#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
+
+/* Two macros to help evaluate the number of rows or columns in each
+ * pass.  This is expressed as a shift - effectively log2 of the number or
+ * rows or columns in each 8x8 tile of the original image.
+ */
+#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
+#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
+
+/* Hence two macros to determine the number of rows or columns in a given
+ * pass of an image given its height or width.  In fact these macros may
+ * return non-zero even though the sub-image is empty, because the other
+ * dimension may be empty for a small image.
+ */
+#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
+   -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
+#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
+   -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
+
+/* For the reader row callbacks (both progressive and sequential) it is
+ * necessary to find the row in the output image given a row in an interlaced
+ * image, so two more macros:
+ */
+#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
+   (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
+#define PNG_COL_FROM_PASS_COL(x_in, pass) \
+   (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
+
+/* Two macros which return a boolean (0 or 1) saying whether the given row
+ * or column is in a particular pass.  These use a common utility macro that
+ * returns a mask for a given pass - the offset 'off' selects the row or
+ * column version.  The mask has the appropriate bit set for each column in
+ * the tile.
+ */
+#define PNG_PASS_MASK(pass,off) ( \
+   ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
+   ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
+
+#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
+   ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
+#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
+   ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
+
+#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
+/* With these routines we avoid an integer divide, which will be slower on
+ * most machines.  However, it does take more operations than the corresponding
+ * divide method, so it may be slower on a few RISC systems.  There are two
+ * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
+ *
+ * Note that the rounding factors are NOT supposed to be the same!  128 and
+ * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
+ * standard method.
+ *
+ * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
+ */
+
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
+
+#  define png_composite(composite, fg, alpha, bg)        \
+   {                                                     \
+      png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
+          * (png_uint_16)(alpha)                         \
+          + (png_uint_16)(bg)*(png_uint_16)(255          \
+          - (png_uint_16)(alpha)) + 128);                \
+      (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
+   }
+
+#  define png_composite_16(composite, fg, alpha, bg)     \
+   {                                                     \
+      png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
+          * (png_uint_32)(alpha)                         \
+          + (png_uint_32)(bg)*(65535                     \
+          - (png_uint_32)(alpha)) + 32768);              \
+      (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
+   }
+
+#else  /* Standard method using integer division */
+
+#  define png_composite(composite, fg, alpha, bg)                      \
+   (composite) =                                                       \
+       (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
+       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+       127) / 255))
+
+#  define png_composite_16(composite, fg, alpha, bg)                       \
+   (composite) =                                                           \
+       (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+       (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +     \
+       32767) / 65535))
+#endif /* READ_COMPOSITE_NODIV */
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
+PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
+PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
+#endif
+
+PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
+    png_const_bytep buf));
+/* No png_get_int_16 -- may be added if there's a real need for it. */
+
+/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
+#endif
+#ifdef PNG_SAVE_INT_32_SUPPORTED
+PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
+#endif
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
+/* No png_save_int_16 -- may be added if there's a real need for it. */
+#endif
+
+#ifdef PNG_USE_READ_MACROS
+/* Inline macros to do direct reads of bytes from the input buffer.
+ * The png_get_int_32() routine assumes we are using two's complement
+ * format for negative values, which is almost certainly true.
+ */
+#  define PNG_get_uint_32(buf) \
+   (((png_uint_32)(*(buf)) << 24) + \
+    ((png_uint_32)(*((buf) + 1)) << 16) + \
+    ((png_uint_32)(*((buf) + 2)) << 8) + \
+    ((png_uint_32)(*((buf) + 3))))
+
+   /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+    * function) incorrectly returned a value of type png_uint_32.
+    */
+#  define PNG_get_uint_16(buf) \
+   ((png_uint_16) \
+    (((unsigned int)(*(buf)) << 8) + \
+    ((unsigned int)(*((buf) + 1)))))
+
+#  define PNG_get_int_32(buf) \
+   ((png_int_32)((*(buf) & 0x80) \
+    ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
+    : (png_int_32)png_get_uint_32(buf)))
+
+/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
+ * but defining a macro name prefixed with PNG_PREFIX.
+ */
+#  ifndef PNG_PREFIX
+#    define png_get_uint_32(buf) PNG_get_uint_32(buf)
+#    define png_get_uint_16(buf) PNG_get_uint_16(buf)
+#    define png_get_int_32(buf)  PNG_get_int_32(buf)
+#  endif
+#else
+#  ifdef PNG_PREFIX
+   /* No macros; revert to the (redefined) function */
+#    define PNG_get_uint_32 (png_get_uint_32)
+#    define PNG_get_uint_16 (png_get_uint_16)
+#    define PNG_get_int_32  (png_get_int_32)
+#  endif
+#endif
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+PNG_EXPORT(242, void, png_set_check_for_invalid_index,
+    (png_structrp png_ptr, int allowed));
+#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
+    png_const_infop info_ptr));
+#  endif
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+/*******************************************************************************
+ * Section 5: SIMPLIFIED API
+ *******************************************************************************
+ *
+ * Please read the documentation in libpng-manual.txt (TODO: write said
+ * documentation) if you don't understand what follows.
+ *
+ * The simplified API hides the details of both libpng and the PNG file format
+ * itself.  It allows PNG files to be read into a very limited number of
+ * in-memory bitmap formats or to be written from the same formats.  If these
+ * formats do not accomodate your needs then you can, and should, use the more
+ * sophisticated APIs above - these support a wide variety of in-memory formats
+ * and a wide variety of sophisticated transformations to those formats as well
+ * as a wide variety of APIs to manipulate ancillary information.
+ *
+ * To read a PNG file using the simplified API:
+ *
+ * 1) Declare a 'png_image' structure (see below) on the stack, set the
+ *    version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
+ *    (this is REQUIRED, your program may crash if you don't do it.)
+ * 2) Call the appropriate png_image_begin_read... function.
+ * 3) Set the png_image 'format' member to the required sample format.
+ * 4) Allocate a buffer for the image and, if required, the color-map.
+ * 5) Call png_image_finish_read to read the image and, if required, the
+ *    color-map into your buffers.
+ *
+ * There are no restrictions on the format of the PNG input itself; all valid
+ * color types, bit depths, and interlace methods are acceptable, and the
+ * input image is transformed as necessary to the requested in-memory format
+ * during the png_image_finish_read() step.  The only caveat is that if you
+ * request a color-mapped image from a PNG that is full-color or makes
+ * complex use of an alpha channel the transformation is extremely lossy and the
+ * result may look terrible.
+ *
+ * To write a PNG file using the simplified API:
+ *
+ * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
+ * 2) Initialize the members of the structure that describe the image, setting
+ *    the 'format' member to the format of the image samples.
+ * 3) Call the appropriate png_image_write... function with a pointer to the
+ *    image and, if necessary, the color-map to write the PNG data.
+ *
+ * png_image is a structure that describes the in-memory format of an image
+ * when it is being read or defines the in-memory format of an image that you
+ * need to write:
+ */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
+    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+
+#define PNG_IMAGE_VERSION 1
+
+typedef struct png_control *png_controlp;
+typedef struct
+{
+   png_controlp opaque;    /* Initialize to NULL, free with png_image_free */
+   png_uint_32  version;   /* Set to PNG_IMAGE_VERSION */
+   png_uint_32  width;     /* Image width in pixels (columns) */
+   png_uint_32  height;    /* Image height in pixels (rows) */
+   png_uint_32  format;    /* Image format as defined below */
+   png_uint_32  flags;     /* A bit mask containing informational flags */
+   png_uint_32  colormap_entries;
+                           /* Number of entries in the color-map */
+
+   /* In the event of an error or warning the following field will be set to a
+    * non-zero value and the 'message' field will contain a '\0' terminated
+    * string with the libpng error or warning message.  If both warnings and
+    * an error were encountered, only the error is recorded.  If there
+    * are multiple warnings, only the first one is recorded.
+    *
+    * The upper 30 bits of this value are reserved, the low two bits contain
+    * a value as follows:
+    */
+#  define PNG_IMAGE_WARNING 1
+#  define PNG_IMAGE_ERROR 2
+   /*
+    * The result is a two-bit code such that a value more than 1 indicates
+    * a failure in the API just called:
+    *
+    *    0 - no warning or error
+    *    1 - warning
+    *    2 - error
+    *    3 - error preceded by warning
+    */
+#  define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
+
+   png_uint_32  warning_or_error;
+
+   char         message[64];
+} png_image, *png_imagep;
+
+/* The samples of the image have one to four channels whose components have
+ * original values in the range 0 to 1.0:
+ *
+ * 1: A single gray or luminance channel (G).
+ * 2: A gray/luminance channel and an alpha channel (GA).
+ * 3: Three red, green, blue color channels (RGB).
+ * 4: Three color channels and an alpha channel (RGBA).
+ *
+ * The components are encoded in one of two ways:
+ *
+ * a) As a small integer, value 0..255, contained in a single byte.  For the
+ * alpha channel the original value is simply value/255.  For the color or
+ * luminance channels the value is encoded according to the sRGB specification
+ * and matches the 8-bit format expected by typical display devices.
+ *
+ * The color/gray channels are not scaled (pre-multiplied) by the alpha
+ * channel and are suitable for passing to color management software.
+ *
+ * b) As a value in the range 0..65535, contained in a 2-byte integer.  All
+ * channels can be converted to the original value by dividing by 65535; all
+ * channels are linear.  Color channels use the RGB encoding (RGB end-points) of
+ * the sRGB specification.  This encoding is identified by the
+ * PNG_FORMAT_FLAG_LINEAR flag below.
+ *
+ * When the simplified API needs to convert between sRGB and linear colorspaces,
+ * the actual sRGB transfer curve defined in the sRGB specification (see the
+ * article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+ * approximation used elsewhere in libpng.
+ *
+ * When an alpha channel is present it is expected to denote pixel coverage
+ * of the color or luminance channels and is returned as an associated alpha
+ * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
+ * value.
+ *
+ * The samples are either contained directly in the image data, between 1 and 8
+ * bytes per pixel according to the encoding, or are held in a color-map indexed
+ * by bytes in the image data.  In the case of a color-map the color-map entries
+ * are individual samples, encoded as above, and the image data has one byte per
+ * pixel to select the relevant sample from the color-map.
+ */
+
+/* PNG_FORMAT_*
+ *
+ * #defines to be used in png_image::format.  Each #define identifies a
+ * particular layout of sample data and, if present, alpha values.  There are
+ * separate defines for each of the two component encodings.
+ *
+ * A format is built up using single bit flag values.  All combinations are
+ * valid.  Formats can be built up from the flag values or you can use one of
+ * the predefined values below.  When testing formats always use the FORMAT_FLAG
+ * macros to test for individual features - future versions of the library may
+ * add new flags.
+ *
+ * When reading or writing color-mapped images the format should be set to the
+ * format of the entries in the color-map then png_image_{read,write}_colormap
+ * called to read or write the color-map and set the format correctly for the
+ * image data.  Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
+ *
+ * NOTE: libpng can be built with particular features disabled. If you see
+ * compiler errors because the definition of one of the following flags has been
+ * compiled out it is because libpng does not have the required support.  It is
+ * possible, however, for the libpng configuration to enable the format on just
+ * read or just write; in that case you may see an error at run time.  You can
+ * guard against this by checking for the definition of the appropriate
+ * "_SUPPORTED" macro, one of:
+ *
+ *    PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
+ */
+#define PNG_FORMAT_FLAG_ALPHA    0x01U /* format with an alpha channel */
+#define PNG_FORMAT_FLAG_COLOR    0x02U /* color format: otherwise grayscale */
+#define PNG_FORMAT_FLAG_LINEAR   0x04U /* 2-byte channels else 1-byte */
+#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
+
+#ifdef PNG_FORMAT_BGR_SUPPORTED
+#  define PNG_FORMAT_FLAG_BGR    0x10U /* BGR colors, else order is RGB */
+#endif
+
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
+#  define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
+#endif
+
+#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
+
+/* Commonly used formats have predefined macros.
+ *
+ * First the single byte (sRGB) formats:
+ */
+#define PNG_FORMAT_GRAY 0
+#define PNG_FORMAT_GA   PNG_FORMAT_FLAG_ALPHA
+#define PNG_FORMAT_AG   (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
+#define PNG_FORMAT_RGB  PNG_FORMAT_FLAG_COLOR
+#define PNG_FORMAT_BGR  (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
+#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
+#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
+
+/* Then the linear 2-byte formats.  When naming these "Y" is used to
+ * indicate a luminance (gray) channel.
+ */
+#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
+#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
+#define PNG_FORMAT_LINEAR_RGB_ALPHA \
+   (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
+
+/* With color-mapped formats the image data is one byte for each pixel, the byte
+ * is an index into the color-map which is formatted as above.  To obtain a
+ * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
+ * to one of the above definitions, or you can use one of the definitions below.
+ */
+#define PNG_FORMAT_RGB_COLORMAP  (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_BGR_COLORMAP  (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
+
+/* PNG_IMAGE macros
+ *
+ * These are convenience macros to derive information from a png_image
+ * structure.  The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
+ * actual image sample values - either the entries in the color-map or the
+ * pixels in the image.  The PNG_IMAGE_PIXEL_ macros return corresponding values
+ * for the pixels and will always return 1 for color-mapped formats.  The
+ * remaining macros return information about the rows in the image and the
+ * complete image.
+ *
+ * NOTE: All the macros that take a png_image::format parameter are compile time
+ * constants if the format parameter is, itself, a constant.  Therefore these
+ * macros can be used in array declarations and case labels where required.
+ * Similarly the macros are also pre-processor constants (sizeof is not used) so
+ * they can be used in #if tests.
+ *
+ * First the information about the samples.
+ */
+#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
+   (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
+   /* Return the total number of channels in a given format: 1..4 */
+
+#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
+   ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
+   /* Return the size in bytes of a single component of a pixel or color-map
+    * entry (as appropriate) in the image: 1 or 2.
+    */
+
+#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
+   (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
+   /* This is the size of the sample data for one sample.  If the image is
+    * color-mapped it is the size of one color-map entry (and image pixels are
+    * one byte in size), otherwise it is the size of one image pixel.
+    */
+
+#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
+   (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
+   /* The maximum size of the color-map required by the format expressed in a
+    * count of components.  This can be used to compile-time allocate a
+    * color-map:
+    *
+    * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+    *
+    * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+    *
+    * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+    * information from one of the png_image_begin_read_ APIs and dynamically
+    * allocate the required memory.
+    */
+
+/* Corresponding information about the pixels */
+#define PNG_IMAGE_PIXEL_(test,fmt)\
+   (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
+
+#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
+   PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
+   /* The number of separate channels (components) in a pixel; 1 for a
+    * color-mapped image.
+    */
+
+#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
+   PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
+   /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
+    * image.
+    */
+
+#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
+   /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
+
+/* Information about the whole row, or whole image */
+#define PNG_IMAGE_ROW_STRIDE(image)\
+   (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
+   /* Return the total number of components in a single row of the image; this
+    * is the minimum 'row stride', the minimum count of components between each
+    * row.  For a color-mapped image this is the minimum number of bytes in a
+    * row.
+    *
+    * WARNING: this macro overflows for some images with more than one component
+    * and very large image widths.  libpng will refuse to process an image where
+    * this macro would overflow.
+    */
+
+#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
+   (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
+   /* Return the size, in bytes, of an image buffer given a png_image and a row
+    * stride - the number of components to leave space for in each row.
+    *
+    * WARNING: this macro overflows a 32-bit integer for some large PNG images,
+    * libpng will refuse to process an image where such an overflow would occur.
+    */
+
+#define PNG_IMAGE_SIZE(image)\
+   PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
+   /* Return the size, in bytes, of the image in memory given just a png_image;
+    * the row stride is the minimum stride required for the image.
+    */
+
+#define PNG_IMAGE_COLORMAP_SIZE(image)\
+   (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
+   /* Return the size, in bytes, of the color-map of this image.  If the image
+    * format is not a color-map format this will return a size sufficient for
+    * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
+    * you don't want to allocate a color-map in this case.
+    */
+
+/* PNG_IMAGE_FLAG_*
+ *
+ * Flags containing additional information about the image are held in the
+ * 'flags' field of png_image.
+ */
+#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
+   /* This indicates the the RGB values of the in-memory bitmap do not
+    * correspond to the red, green and blue end-points defined by sRGB.
+    */
+
+#define PNG_IMAGE_FLAG_FAST 0x02
+   /* On write emphasise speed over compression; the resultant PNG file will be
+    * larger but will be produced significantly faster, particular for large
+    * images.  Do not use this option for images which will be distributed, only
+    * used it when producing intermediate files that will be read back in
+    * repeatedly.  For a typical 24-bit image the option will double the read
+    * speed at the cost of increasing the image size by 25%, however for many
+    * more compressible images the PNG file can be 10 times larger with only a
+    * slight speed gain.
+    */
+
+#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
+   /* On read if the image is a 16-bit per component image and there is no gAMA
+    * or sRGB chunk assume that the components are sRGB encoded.  Notice that
+    * images output by the simplified API always have gamma information; setting
+    * this flag only affects the interpretation of 16-bit images from an
+    * external source.  It is recommended that the application expose this flag
+    * to the user; the user can normally easily recognize the difference between
+    * linear and sRGB encoding.  This flag has no effect on write - the data
+    * passed to the write APIs must have the correct encoding (as defined
+    * above.)
+    *
+    * If the flag is not set (the default) input 16-bit per component data is
+    * assumed to be linear.
+    *
+    * NOTE: the flag can only be set after the png_image_begin_read_ call,
+    * because that call initializes the 'flags' field.
+    */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* READ APIs
+ * ---------
+ *
+ * The png_image passed to the read APIs must have been initialized by setting
+ * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
+ */
+#ifdef PNG_STDIO_SUPPORTED
+PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
+   const char *file_name));
+   /* The named file is opened for read and the image header is filled in
+    * from the PNG header in the file.
+    */
+
+PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
+   FILE* file));
+   /* The PNG header is read from the stdio FILE object. */
+#endif /* STDIO */
+
+PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
+   png_const_voidp memory, png_size_t size));
+   /* The PNG header is read from the given memory buffer. */
+
+PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
+   png_const_colorp background, void *buffer, png_int_32 row_stride,
+   void *colormap));
+   /* Finish reading the image into the supplied buffer and clean up the
+    * png_image structure.
+    *
+    * row_stride is the step, in byte or 2-byte units as appropriate,
+    * between adjacent rows.  A positive stride indicates that the top-most row
+    * is first in the buffer - the normal top-down arrangement.  A negative
+    * stride indicates that the bottom-most row is first in the buffer.
+    *
+    * background need only be supplied if an alpha channel must be removed from
+    * a png_byte format and the removal is to be done by compositing on a solid
+    * color; otherwise it may be NULL and any composition will be done directly
+    * onto the buffer.  The value is an sRGB color to use for the background,
+    * for grayscale output the green channel is used.
+    *
+    * background must be supplied when an alpha channel must be removed from a
+    * single byte color-mapped output format, in other words if:
+    *
+    * 1) The original format from png_image_begin_read_from_* had
+    *    PNG_FORMAT_FLAG_ALPHA set.
+    * 2) The format set by the application does not.
+    * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
+    *    PNG_FORMAT_FLAG_LINEAR *not* set.
+    *
+    * For linear output removing the alpha channel is always done by compositing
+    * on black and background is ignored.
+    *
+    * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set.  It must
+    * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
+    * image->colormap_entries will be updated to the actual number of entries
+    * written to the colormap; this may be less than the original value.
+    */
+
+PNG_EXPORT(238, void, png_image_free, (png_imagep image));
+   /* Free any data allocated by libpng in image->opaque, setting the pointer to
+    * NULL.  May be called at any time after the structure is initialized.
+    */
+#endif /* SIMPLIFIED_READ */
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+/* WRITE APIS
+ * ----------
+ * For write you must initialize a png_image structure to describe the image to
+ * be written.  To do this use memset to set the whole structure to 0 then
+ * initialize fields describing your image.
+ *
+ * version: must be set to PNG_IMAGE_VERSION
+ * opaque: must be initialized to NULL
+ * width: image width in pixels
+ * height: image height in rows
+ * format: the format of the data (image and color-map) you wish to write
+ * flags: set to 0 unless one of the defined flags applies; set
+ *    PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
+ *    values do not correspond to the colors in sRGB.
+ * colormap_entries: set to the number of entries in the color-map (0 to 256)
+ */
+#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
+   const char *file, int convert_to_8bit, const void *buffer,
+   png_int_32 row_stride, const void *colormap));
+   /* Write the image to the named file. */
+
+PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
+   int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
+   const void *colormap));
+   /* Write the image to the given (FILE*). */
+#endif /* SIMPLIFIED_WRITE_STDIO */
+
+/* With all write APIs if image is in one of the linear formats with 16-bit
+ * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
+ * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
+ * encoded PNG file is written.
+ *
+ * With color-mapped data formats the colormap parameter point to a color-map
+ * with at least image->colormap_entries encoded in the specified format.  If
+ * the format is linear the written PNG color-map will be converted to sRGB
+ * regardless of the convert_to_8_bit flag.
+ *
+ * With all APIs row_stride is handled as in the read APIs - it is the spacing
+ * from one row to the next in component sized units (1 or 2 bytes) and if
+ * negative indicates a bottom-up row layout in the buffer.  If row_stride is
+ * zero, libpng will calculate it for you from the image width and number of
+ * channels.
+ *
+ * Note that the write API does not support interlacing, sub-8-bit pixels or
+ * most ancillary chunks.  If you need to write text chunks (e.g. for copyright
+ * notices) you need to use one of the other APIs.
+ */
+
+PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
+   png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
+   const void *buffer, png_int_32 row_stride, const void *colormap));
+   /* Write the image to the given memory buffer.  The function both writes the
+    * whole PNG data stream to *memory and updates *memory_bytes with the count
+    * of bytes written.
+    *
+    * 'memory' may be NULL.  In this case *memory_bytes is not read however on
+    * success the number of bytes which would have been written will still be
+    * stored in *memory_bytes.  On failure *memory_bytes will contain 0.
+    *
+    * If 'memory' is not NULL it must point to memory[*memory_bytes] of
+    * writeable memory.
+    *
+    * If the function returns success memory[*memory_bytes] (if 'memory' is not
+    * NULL) contains the written PNG data.  *memory_bytes will always be less
+    * than or equal to the original value.
+    *
+    * If the function returns false and *memory_bytes was not changed an error
+    * occured during write.  If *memory_bytes was changed, or is not 0 if
+    * 'memory' was NULL, the write would have succeeded but for the memory
+    * buffer being too small.  *memory_bytes contains the required number of
+    * bytes and will be bigger that the original value.
+    */
+
+#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
+   row_stride, colormap)\
+   png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
+         row_stride, colormap)
+   /* Return the amount of memory in 'size' required to compress this image.
+    * The png_image structure 'image' must be filled in as in the above
+    * function and must not be changed before the actual write call, the buffer
+    * and all other parameters must also be identical to that in the final
+    * write call.  The 'size' variable need not be initialized.
+    *
+    * NOTE: the macro returns true/false, if false is returned 'size' will be
+    * set to zero and the write failed and probably will fail if tried again.
+    */
+
+/* You can pre-allocate the buffer by making sure it is of sufficient size
+ * regardless of the amount of compression achieved.  The buffer size will
+ * always be bigger than the original image and it will never be filled.  The
+ * following macros are provided to assist in allocating the buffer.
+ */
+#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
+   /* The number of uncompressed bytes in the PNG byte encoding of the image;
+    * uncompressing the PNG IDAT data will give this number of bytes.
+    *
+    * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
+    * macro can because of the extra bytes used in the PNG byte encoding.  You
+    * need to avoid this macro if your image size approaches 2^30 in width or
+    * height.  The same goes for the remainder of these macros; they all produce
+    * bigger numbers than the actual in-memory image size.
+    */
+#ifndef PNG_ZLIB_MAX_SIZE
+#  define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
+   /* An upper bound on the number of compressed bytes given 'b' uncompressed
+    * bytes.  This is based on deflateBounds() in zlib; different
+    * implementations of zlib compression may conceivably produce more data so
+    * if your zlib implementation is not zlib itself redefine this macro
+    * appropriately.
+    */
+#endif
+
+#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
+   PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
+   /* An upper bound on the size of the data in the PNG IDAT chunks. */
+
+#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
+   ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
+    (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
+    12U+3U*(image).colormap_entries/*PLTE data*/+\
+    (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
+    12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
+    12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
+   /* A helper for the following macro; if your compiler cannot handle the
+    * following macro use this one with the result of
+    * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
+    * compilers should handle this just fine.)
+    */
+
+#define PNG_IMAGE_PNG_SIZE_MAX(image)\
+   PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
+   /* An upper bound on the total length of the PNG data stream for 'image'.
+    * The result is of type png_alloc_size_t, on 32-bit systems this may
+    * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
+    * run out of buffer space but return a corrected size which should work.
+    */
+#endif /* SIMPLIFIED_WRITE */
+/*******************************************************************************
+ *  END OF SIMPLIFIED API
+ ******************************************************************************/
+#endif /* SIMPLIFIED_{READ|WRITE} */
+
+/*******************************************************************************
+ * Section 6: IMPLEMENTATION OPTIONS
+ *******************************************************************************
+ *
+ * Support for arbitrary implementation-specific optimizations.  The API allows
+ * particular options to be turned on or off.  'Option' is the number of the
+ * option and 'onoff' is 0 (off) or non-0 (on).  The value returned is given
+ * by the PNG_OPTION_ defines below.
+ *
+ * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
+ *           are detected at run time, however sometimes it may be impossible
+ *           to do this in user mode, in which case it is necessary to discover
+ *           the capabilities in an OS specific way.  Such capabilities are
+ *           listed here when libpng has support for them and must be turned
+ *           ON by the application if present.
+ *
+ * SOFTWARE: sometimes software optimizations actually result in performance
+ *           decrease on some architectures or systems, or with some sets of
+ *           PNG images.  'Software' options allow such optimizations to be
+ *           selected at run time.
+ */
+#ifdef PNG_SET_OPTION_SUPPORTED
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+#  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
+#endif
+#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
+#ifdef PNG_MIPS_MSA_API_SUPPORTED
+#  define PNG_MIPS_MSA   6 /* HARDWARE: MIPS Msa SIMD instructions supported */
+#endif
+#define PNG_IGNORE_ADLER32 8
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+#  define PNG_POWERPC_VSX   10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
+#endif
+#define PNG_OPTION_NEXT  12 /* Next option - numbers must be even */
+
+/* Return values: NOTE: there are four values and 'off' is *not* zero */
+#define PNG_OPTION_UNSET   0 /* Unset - defaults to off */
+#define PNG_OPTION_INVALID 1 /* Option number out of range */
+#define PNG_OPTION_OFF     2
+#define PNG_OPTION_ON      3
+
+PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
+   int onoff));
+#endif /* SET_OPTION */
+
+/*******************************************************************************
+ *  END OF HARDWARE AND SOFTWARE OPTIONS
+ ******************************************************************************/
+
+/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+ * defs, and in scripts/symbols.def.
+ */
+
+/* The last ordinal number (this is the *last* one already used; the next
+ * one to use is one more than this.)
+ */
+#ifdef PNG_EXPORT_LAST_ORDINAL
+  PNG_EXPORT_LAST_ORDINAL(249);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+/* Do not put anything past this line */
+#endif /* PNG_H */
diff --git a/xs/src/png/libpng/pngconf.h b/xs/src/png/libpng/pngconf.h
new file mode 100644
index 000000000..d13b13e57
--- /dev/null
+++ b/xs/src/png/libpng/pngconf.h
@@ -0,0 +1,622 @@
+
+/* pngconf.h - machine configurable file for libpng
+ *
+ * libpng version 1.6.34, September 29, 2017
+ *
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Any machine specific code is near the front of this file, so if you
+ * are configuring libpng for a machine, you may want to read the section
+ * starting here down to where it starts to typedef png_color, png_text,
+ * and png_info.
+ */
+
+#ifndef PNGCONF_H
+#define PNGCONF_H
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
+
+/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
+ * compiler for correct compilation.  The following header files are required by
+ * the standard.  If your compiler doesn't provide these header files, or they
+ * do not match the standard, you will need to provide/improve them.
+ */
+#include <limits.h>
+#include <stddef.h>
+
+/* Library header files.  These header files are all defined by ISOC90; libpng
+ * expects conformant implementations, however, an ISOC90 conformant system need
+ * not provide these header files if the functionality cannot be implemented.
+ * In this case it will be necessary to disable the relevant parts of libpng in
+ * the build of pnglibconf.h.
+ *
+ * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
+ * include this unnecessary header file.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+   /* Required for the definition of FILE: */
+#  include <stdio.h>
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+   /* Required for the definition of jmp_buf and the declaration of longjmp: */
+#  include <setjmp.h>
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+   /* Required for struct tm: */
+#  include <time.h>
+#endif
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using
+ * PNG_NO_CONST; this is no longer supported except for data declarations which
+ * apparently still cause problems in 2011 on some compilers.
+ */
+#define PNG_CONST const /* backward compatibility only */
+
+/* This controls optimization of the reading of 16-bit and 32-bit values
+ * from PNG files.  It can be set on a per-app-file basis - it
+ * just changes whether a macro is used when the function is called.
+ * The library builder sets the default; if read functions are not
+ * built into the library the macro implementation is forced on.
+ */
+#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
+#  define PNG_USE_READ_MACROS
+#endif
+#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
+#  if PNG_DEFAULT_READ_MACROS
+#    define PNG_USE_READ_MACROS
+#  endif
+#endif
+
+/* COMPILER SPECIFIC OPTIONS.
+ *
+ * These options are provided so that a variety of difficult compilers
+ * can be used.  Some are fixed at build time (e.g. PNG_API_RULE
+ * below) but still have compiler specific implementations, others
+ * may be changed on a per-file basis when compiling against libpng.
+ */
+
+/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
+ * against legacy (pre ISOC90) compilers that did not understand function
+ * prototypes.  It is not required for modern C compilers.
+ */
+#ifndef PNGARG
+#  define PNGARG(arglist) arglist
+#endif
+
+/* Function calling conventions.
+ * =============================
+ * Normally it is not necessary to specify to the compiler how to call
+ * a function - it just does it - however on x86 systems derived from
+ * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
+ * and some others) there are multiple ways to call a function and the
+ * default can be changed on the compiler command line.  For this reason
+ * libpng specifies the calling convention of every exported function and
+ * every function called via a user supplied function pointer.  This is
+ * done in this file by defining the following macros:
+ *
+ * PNGAPI    Calling convention for exported functions.
+ * PNGCBAPI  Calling convention for user provided (callback) functions.
+ * PNGCAPI   Calling convention used by the ANSI-C library (required
+ *           for longjmp callbacks and sometimes used internally to
+ *           specify the calling convention for zlib).
+ *
+ * These macros should never be overridden.  If it is necessary to
+ * change calling convention in a private build this can be done
+ * by setting PNG_API_RULE (which defaults to 0) to one of the values
+ * below to select the correct 'API' variants.
+ *
+ * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
+ *                This is correct in every known environment.
+ * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
+ *                the 'C' calling convention (from PNGCAPI) for
+ *                callbacks (PNGCBAPI).  This is no longer required
+ *                in any known environment - if it has to be used
+ *                please post an explanation of the problem to the
+ *                libpng mailing list.
+ *
+ * These cases only differ if the operating system does not use the C
+ * calling convention, at present this just means the above cases
+ * (x86 DOS/Windows sytems) and, even then, this does not apply to
+ * Cygwin running on those systems.
+ *
+ * Note that the value must be defined in pnglibconf.h so that what
+ * the application uses to call the library matches the conventions
+ * set when building the library.
+ */
+
+/* Symbol export
+ * =============
+ * When building a shared library it is almost always necessary to tell
+ * the compiler which symbols to export.  The png.h macro 'PNG_EXPORT'
+ * is used to mark the symbols.  On some systems these symbols can be
+ * extracted at link time and need no special processing by the compiler,
+ * on other systems the symbols are flagged by the compiler and just
+ * the declaration requires a special tag applied (unfortunately) in a
+ * compiler dependent way.  Some systems can do either.
+ *
+ * A small number of older systems also require a symbol from a DLL to
+ * be flagged to the program that calls it.  This is a problem because
+ * we do not know in the header file included by application code that
+ * the symbol will come from a shared library, as opposed to a statically
+ * linked one.  For this reason the application must tell us by setting
+ * the magic flag PNG_USE_DLL to turn on the special processing before
+ * it includes png.h.
+ *
+ * Four additional macros are used to make this happen:
+ *
+ * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
+ *            the build or imported if PNG_USE_DLL is set - compiler
+ *            and system specific.
+ *
+ * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
+ *                       'type', compiler specific.
+ *
+ * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
+ *                make a symbol exported from the DLL.  Not used in the
+ *                public header files; see pngpriv.h for how it is used
+ *                in the libpng build.
+ *
+ * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
+ *                from a DLL - used to define PNG_IMPEXP when
+ *                PNG_USE_DLL is set.
+ */
+
+/* System specific discovery.
+ * ==========================
+ * This code is used at build time to find PNG_IMPEXP, the API settings
+ * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
+ * import processing is possible.  On Windows systems it also sets
+ * compiler-specific macros to the values required to change the calling
+ * conventions of the various functions.
+ */
+#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+  /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
+   * MinGW on any architecture currently supported by Windows.  Also includes
+   * Watcom builds but these need special treatment because they are not
+   * compatible with GCC or Visual C because of different calling conventions.
+   */
+#  if PNG_API_RULE == 2
+   /* If this line results in an error, either because __watcall is not
+    * understood or because of a redefine just below you cannot use *this*
+    * build of the library with the compiler you are using.  *This* build was
+    * build using Watcom and applications must also be built using Watcom!
+    */
+#    define PNGCAPI __watcall
+#  endif
+
+#  if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
+#    define PNGCAPI __cdecl
+#    if PNG_API_RULE == 1
+   /* If this line results in an error __stdcall is not understood and
+    * PNG_API_RULE should not have been set to '1'.
+    */
+#      define PNGAPI __stdcall
+#    endif
+#  else
+   /* An older compiler, or one not detected (erroneously) above,
+    * if necessary override on the command line to get the correct
+    * variants for the compiler.
+    */
+#    ifndef PNGCAPI
+#      define PNGCAPI _cdecl
+#    endif
+#    if PNG_API_RULE == 1 && !defined(PNGAPI)
+#      define PNGAPI _stdcall
+#    endif
+#  endif /* compiler/api */
+
+  /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
+
+#  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
+#     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
+#  endif
+
+#  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
+      (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
+   /* older Borland and MSC
+    * compilers used '__export' and required this to be after
+    * the type.
+    */
+#    ifndef PNG_EXPORT_TYPE
+#      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
+#    endif
+#    define PNG_DLL_EXPORT __export
+#  else /* newer compiler */
+#    define PNG_DLL_EXPORT __declspec(dllexport)
+#    ifndef PNG_DLL_IMPORT
+#      define PNG_DLL_IMPORT __declspec(dllimport)
+#    endif
+#  endif /* compiler */
+
+#else /* !Windows */
+#  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
+#    define PNGAPI _System
+#  else /* !Windows/x86 && !OS/2 */
+   /* Use the defaults, or define PNG*API on the command line (but
+    * this will have to be done for every compile!)
+    */
+#  endif /* other system, !OS/2 */
+#endif /* !Windows/x86 */
+
+/* Now do all the defaulting . */
+#ifndef PNGCAPI
+#  define PNGCAPI
+#endif
+#ifndef PNGCBAPI
+#  define PNGCBAPI PNGCAPI
+#endif
+#ifndef PNGAPI
+#  define PNGAPI PNGCAPI
+#endif
+
+/* PNG_IMPEXP may be set on the compilation system command line or (if not set)
+ * then in an internal header file when building the library, otherwise (when
+ * using the library) it is set here.
+ */
+#ifndef PNG_IMPEXP
+#  if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
+   /* This forces use of a DLL, disallowing static linking */
+#    define PNG_IMPEXP PNG_DLL_IMPORT
+#  endif
+
+#  ifndef PNG_IMPEXP
+#    define PNG_IMPEXP
+#  endif
+#endif
+
+/* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
+ * 'attributes' as a storage class - the attributes go at the start of the
+ * function definition, and attributes are always appended regardless of the
+ * compiler.  This considerably simplifies these macros but may cause problems
+ * if any compilers both need function attributes and fail to handle them as
+ * a storage class (this is unlikely.)
+ */
+#ifndef PNG_FUNCTION
+#  define PNG_FUNCTION(type, name, args, attributes) attributes type name args
+#endif
+
+#ifndef PNG_EXPORT_TYPE
+#  define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
+#endif
+
+   /* The ordinal value is only relevant when preprocessing png.h for symbol
+    * table entries, so we discard it here.  See the .dfn files in the
+    * scripts directory.
+    */
+
+#ifndef PNG_EXPORTA
+#  define PNG_EXPORTA(ordinal, type, name, args, attributes) \
+      PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \
+      PNG_LINKAGE_API attributes)
+#endif
+
+/* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
+ * so make something non-empty to satisfy the requirement:
+ */
+#define PNG_EMPTY /*empty list*/
+
+#define PNG_EXPORT(ordinal, type, name, args) \
+   PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
+
+/* Use PNG_REMOVED to comment out a removed interface. */
+#ifndef PNG_REMOVED
+#  define PNG_REMOVED(ordinal, type, name, args, attributes)
+#endif
+
+#ifndef PNG_CALLBACK
+#  define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args)
+#endif
+
+/* Support for compiler specific function attributes.  These are used
+ * so that where compiler support is available incorrect use of API
+ * functions in png.h will generate compiler warnings.
+ *
+ * Added at libpng-1.2.41.
+ */
+
+#ifndef PNG_NO_PEDANTIC_WARNINGS
+#  ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
+#    define PNG_PEDANTIC_WARNINGS_SUPPORTED
+#  endif
+#endif
+
+#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
+  /* Support for compiler specific function attributes.  These are used
+   * so that where compiler support is available, incorrect use of API
+   * functions in png.h will generate compiler warnings.  Added at libpng
+   * version 1.2.41.  Disabling these removes the warnings but may also produce
+   * less efficient code.
+   */
+#  if defined(__clang__) && defined(__has_attribute)
+   /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
+#    if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
+#      define PNG_NORETURN __attribute__((__noreturn__))
+#    endif
+#    if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
+#      define PNG_ALLOCATED __attribute__((__malloc__))
+#    endif
+#    if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
+#      define PNG_DEPRECATED __attribute__((__deprecated__))
+#    endif
+#    if !defined(PNG_PRIVATE)
+#      ifdef __has_extension
+#        if __has_extension(attribute_unavailable_with_message)
+#          define PNG_PRIVATE __attribute__((__unavailable__(\
+             "This function is not exported by libpng.")))
+#        endif
+#      endif
+#    endif
+#    ifndef PNG_RESTRICT
+#      define PNG_RESTRICT __restrict
+#    endif
+
+#  elif defined(__GNUC__)
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN   __attribute__((__noreturn__))
+#    endif
+#    if __GNUC__ >= 3
+#      ifndef PNG_ALLOCATED
+#        define PNG_ALLOCATED  __attribute__((__malloc__))
+#      endif
+#      ifndef PNG_DEPRECATED
+#        define PNG_DEPRECATED __attribute__((__deprecated__))
+#      endif
+#      ifndef PNG_PRIVATE
+#        if 0 /* Doesn't work so we use deprecated instead*/
+#          define PNG_PRIVATE \
+            __attribute__((warning("This function is not exported by libpng.")))
+#        else
+#          define PNG_PRIVATE \
+            __attribute__((__deprecated__))
+#        endif
+#      endif
+#      if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+#        ifndef PNG_RESTRICT
+#          define PNG_RESTRICT __restrict
+#        endif
+#      endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
+#    endif /* __GNUC__ >= 3 */
+
+#  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT /* not supported */
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN   __declspec(noreturn)
+#    endif
+#    ifndef PNG_ALLOCATED
+#      if (_MSC_VER >= 1400)
+#        define PNG_ALLOCATED __declspec(restrict)
+#      endif
+#    endif
+#    ifndef PNG_DEPRECATED
+#      define PNG_DEPRECATED __declspec(deprecated)
+#    endif
+#    ifndef PNG_PRIVATE
+#      define PNG_PRIVATE __declspec(deprecated)
+#    endif
+#    ifndef PNG_RESTRICT
+#      if (_MSC_VER >= 1400)
+#        define PNG_RESTRICT __restrict
+#      endif
+#    endif
+
+#  elif defined(__WATCOMC__)
+#    ifndef PNG_RESTRICT
+#      define PNG_RESTRICT __restrict
+#    endif
+#  endif
+#endif /* PNG_PEDANTIC_WARNINGS */
+
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED  /* Use of this function is deprecated */
+#endif
+#ifndef PNG_USE_RESULT
+#  define PNG_USE_RESULT  /* The result of this function must be checked */
+#endif
+#ifndef PNG_NORETURN
+#  define PNG_NORETURN    /* This function does not return */
+#endif
+#ifndef PNG_ALLOCATED
+#  define PNG_ALLOCATED   /* The result of the function is new memory */
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE     /* This is a private libpng function */
+#endif
+#ifndef PNG_RESTRICT
+#  define PNG_RESTRICT    /* The C99 "restrict" feature */
+#endif
+
+#ifndef PNG_FP_EXPORT     /* A floating point API. */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+#     define PNG_FP_EXPORT(ordinal, type, name, args)\
+         PNG_EXPORT(ordinal, type, name, args);
+#  else                   /* No floating point APIs */
+#     define PNG_FP_EXPORT(ordinal, type, name, args)
+#  endif
+#endif
+#ifndef PNG_FIXED_EXPORT  /* A fixed point API. */
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+         PNG_EXPORT(ordinal, type, name, args);
+#  else                   /* No fixed point APIs */
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)
+#  endif
+#endif
+
+#ifndef PNG_BUILDING_SYMBOL_TABLE
+/* Some typedefs to get us started.  These should be safe on most of the common
+ * platforms.
+ *
+ * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
+ * 32-bit value however this is not normally advisable.
+ *
+ * png_uint_16 and png_int_16 should always be two bytes in size - this is
+ * verified at library build time.
+ *
+ * png_byte must always be one byte in size.
+ *
+ * The checks below use constants from limits.h, as defined by the ISOC90
+ * standard.
+ */
+#if CHAR_BIT == 8 && UCHAR_MAX == 255
+   typedef unsigned char png_byte;
+#else
+#  error "libpng requires 8-bit bytes"
+#endif
+
+#if INT_MIN == -32768 && INT_MAX == 32767
+   typedef int png_int_16;
+#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
+   typedef short png_int_16;
+#else
+#  error "libpng requires a signed 16-bit type"
+#endif
+
+#if UINT_MAX == 65535
+   typedef unsigned int png_uint_16;
+#elif USHRT_MAX == 65535
+   typedef unsigned short png_uint_16;
+#else
+#  error "libpng requires an unsigned 16-bit type"
+#endif
+
+#if INT_MIN < -2147483646 && INT_MAX > 2147483646
+   typedef int png_int_32;
+#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
+   typedef long int png_int_32;
+#else
+#  error "libpng requires a signed 32-bit (or more) type"
+#endif
+
+#if UINT_MAX > 4294967294U
+   typedef unsigned int png_uint_32;
+#elif ULONG_MAX > 4294967294U
+   typedef unsigned long int png_uint_32;
+#else
+#  error "libpng requires an unsigned 32-bit (or more) type"
+#endif
+
+/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however,
+ * requires an ISOC90 compiler and relies on consistent behavior of sizeof.
+ */
+typedef size_t png_size_t;
+typedef ptrdiff_t png_ptrdiff_t;
+
+/* libpng needs to know the maximum value of 'size_t' and this controls the
+ * definition of png_alloc_size_t, below.  This maximum value of size_t limits
+ * but does not control the maximum allocations the library makes - there is
+ * direct application control of this through png_set_user_limits().
+ */
+#ifndef PNG_SMALL_SIZE_T
+   /* Compiler specific tests for systems where size_t is known to be less than
+    * 32 bits (some of these systems may no longer work because of the lack of
+    * 'far' support; see above.)
+    */
+#  if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
+   (defined(_MSC_VER) && defined(MAXSEG_64K))
+#     define PNG_SMALL_SIZE_T
+#  endif
+#endif
+
+/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no
+ * smaller than png_uint_32.  Casts from png_size_t or png_uint_32 to
+ * png_alloc_size_t are not necessary; in fact, it is recommended not to use
+ * them at all so that the compiler can complain when something turns out to be
+ * problematic.
+ *
+ * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect to
+ * encounter practical situations that require such conversions.
+ *
+ * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
+ * 4294967295 - i.e. less than the maximum value of png_uint_32.
+ */
+#ifdef PNG_SMALL_SIZE_T
+   typedef png_uint_32 png_alloc_size_t;
+#else
+   typedef png_size_t png_alloc_size_t;
+#endif
+
+/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
+ * implementations of Intel CPU specific support of user-mode segmented address
+ * spaces, where 16-bit pointers address more than 65536 bytes of memory using
+ * separate 'segment' registers.  The implementation requires two different
+ * types of pointer (only one of which includes the segment value.)
+ *
+ * If required this support is available in version 1.2 of libpng and may be
+ * available in versions through 1.5, although the correctness of the code has
+ * not been verified recently.
+ */
+
+/* Typedef for floating-point numbers that are converted to fixed-point with a
+ * multiple of 100,000, e.g., gamma
+ */
+typedef png_int_32 png_fixed_point;
+
+/* Add typedefs for pointers */
+typedef void                  * png_voidp;
+typedef const void            * png_const_voidp;
+typedef png_byte              * png_bytep;
+typedef const png_byte        * png_const_bytep;
+typedef png_uint_32           * png_uint_32p;
+typedef const png_uint_32     * png_const_uint_32p;
+typedef png_int_32            * png_int_32p;
+typedef const png_int_32      * png_const_int_32p;
+typedef png_uint_16           * png_uint_16p;
+typedef const png_uint_16     * png_const_uint_16p;
+typedef png_int_16            * png_int_16p;
+typedef const png_int_16      * png_const_int_16p;
+typedef char                  * png_charp;
+typedef const char            * png_const_charp;
+typedef png_fixed_point       * png_fixed_point_p;
+typedef const png_fixed_point * png_const_fixed_point_p;
+typedef png_size_t            * png_size_tp;
+typedef const png_size_t      * png_const_size_tp;
+
+#ifdef PNG_STDIO_SUPPORTED
+typedef FILE            * png_FILE_p;
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double       * png_doublep;
+typedef const double * png_const_doublep;
+#endif
+
+/* Pointers to pointers; i.e. arrays */
+typedef png_byte        * * png_bytepp;
+typedef png_uint_32     * * png_uint_32pp;
+typedef png_int_32      * * png_int_32pp;
+typedef png_uint_16     * * png_uint_16pp;
+typedef png_int_16      * * png_int_16pp;
+typedef const char      * * png_const_charpp;
+typedef char            * * png_charpp;
+typedef png_fixed_point * * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+typedef double          * * png_doublepp;
+#endif
+
+/* Pointers to pointers to pointers; i.e., pointer to array */
+typedef char            * * * png_charppp;
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+#endif /* PNGCONF_H */
diff --git a/xs/src/png/libpng/pngdebug.h b/xs/src/png/libpng/pngdebug.h
new file mode 100644
index 000000000..15a7ed0c9
--- /dev/null
+++ b/xs/src/png/libpng/pngdebug.h
@@ -0,0 +1,153 @@
+
+/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
+ *
+ * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* Define PNG_DEBUG at compile time for debugging information.  Higher
+ * numbers for PNG_DEBUG mean more debugging information.  This has
+ * only been added since version 0.95 so it is not implemented throughout
+ * libpng yet, but more support will be added as needed.
+ *
+ * png_debug[1-2]?(level, message ,arg{0-2})
+ *   Expands to a statement (either a simple expression or a compound
+ *   do..while(0) statement) that outputs a message with parameter
+ *   substitution if PNG_DEBUG is defined to 2 or more.  If PNG_DEBUG
+ *   is undefined, 0 or 1 every png_debug expands to a simple expression
+ *   (actually ((void)0)).
+ *
+ *   level: level of detail of message, starting at 0.  A level 'n'
+ *          message is preceded by 'n' 3-space indentations (not implemented
+ *          on Microsoft compilers unless PNG_DEBUG_FILE is also
+ *          defined, to allow debug DLL compilation with no standard IO).
+ *   message: a printf(3) style text string.  A trailing '\n' is added
+ *            to the message.
+ *   arg: 0 to 2 arguments for printf(3) style substitution in message.
+ */
+#ifndef PNGDEBUG_H
+#define PNGDEBUG_H
+/* These settings control the formatting of messages in png.c and pngerror.c */
+/* Moved to pngdebug.h at 1.5.0 */
+#  ifndef PNG_LITERAL_SHARP
+#    define PNG_LITERAL_SHARP 0x23
+#  endif
+#  ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET
+#    define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b
+#  endif
+#  ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET
+#    define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d
+#  endif
+#  ifndef PNG_STRING_NEWLINE
+#    define PNG_STRING_NEWLINE "\n"
+#  endif
+
+#ifdef PNG_DEBUG
+#  if (PNG_DEBUG > 0)
+#    if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
+#      include <crtdbg.h>
+#      if (PNG_DEBUG > 1)
+#        ifndef _DEBUG
+#          define _DEBUG
+#        endif
+#        ifndef png_debug
+#          define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
+#        endif
+#        ifndef png_debug1
+#          define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
+#        endif
+#        ifndef png_debug2
+#          define png_debug2(l,m,p1,p2) \
+             _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
+#        endif
+#      endif
+#    else /* PNG_DEBUG_FILE || !_MSC_VER */
+#      ifndef PNG_STDIO_SUPPORTED
+#        include <stdio.h> /* not included yet */
+#      endif
+#      ifndef PNG_DEBUG_FILE
+#        define PNG_DEBUG_FILE stderr
+#      endif /* PNG_DEBUG_FILE */
+
+#      if (PNG_DEBUG > 1)
+#        ifdef __STDC__
+#          ifndef png_debug
+#            define png_debug(l,m) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : "")))); \
+       } while (0)
+#          endif
+#          ifndef png_debug1
+#            define png_debug1(l,m,p1) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1); \
+       } while (0)
+#          endif
+#          ifndef png_debug2
+#            define png_debug2(l,m,p1,p2) \
+       do { \
+       int num_tabs=l; \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1,p2);\
+       } while (0)
+#          endif
+#        else /* __STDC __ */
+#          ifndef png_debug
+#            define png_debug(l,m) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format); \
+       } while (0)
+#          endif
+#          ifndef png_debug1
+#            define png_debug1(l,m,p1) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format,p1); \
+       } while (0)
+#          endif
+#          ifndef png_debug2
+#            define png_debug2(l,m,p1,p2) \
+       do { \
+       int num_tabs=l; \
+       char format[256]; \
+       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
+         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
+         m,PNG_STRING_NEWLINE); \
+       fprintf(PNG_DEBUG_FILE,format,p1,p2); \
+       } while (0)
+#          endif
+#        endif /* __STDC __ */
+#      endif /* (PNG_DEBUG > 1) */
+
+#    endif /* _MSC_VER */
+#  endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#  define png_debug(l, m) ((void)0)
+#endif
+#ifndef png_debug1
+#  define png_debug1(l, m, p1) ((void)0)
+#endif
+#ifndef png_debug2
+#  define png_debug2(l, m, p1, p2) ((void)0)
+#endif
+#endif /* PNGDEBUG_H */
diff --git a/xs/src/png/libpng/pngerror.c b/xs/src/png/libpng/pngerror.c
new file mode 100644
index 000000000..ad48bfb98
--- /dev/null
+++ b/xs/src/png/libpng/pngerror.c
@@ -0,0 +1,963 @@
+
+/* pngerror.c - stub functions for i/o and memory allocation
+ *
+ * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all error handling.  Users who
+ * need special error handling are expected to write replacement functions
+ * and use png_set_error_fn() to use those functions.  See the instructions
+ * at each function.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
+    png_const_charp error_message)),PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+static void /* PRIVATE */
+png_default_warning PNGARG((png_const_structrp png_ptr,
+    png_const_charp warning_message));
+#endif /* WARNINGS */
+
+/* This function is called whenever there is a fatal error.  This function
+ * should not be changed.  If there is a need to handle errors differently,
+ * you should supply a replacement error function and use png_set_error_fn()
+ * to replace the error function at run-time.
+ */
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+PNG_FUNCTION(void,PNGAPI
+png_error,(png_const_structrp png_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   char msg[16];
+   if (png_ptr != NULL)
+   {
+      if ((png_ptr->flags &
+         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+      {
+         if (*error_message == PNG_LITERAL_SHARP)
+         {
+            /* Strip "#nnnn " from beginning of error message. */
+            int offset;
+            for (offset = 1; offset<15; offset++)
+               if (error_message[offset] == ' ')
+                  break;
+
+            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+            {
+               int i;
+               for (i = 0; i < offset - 1; i++)
+                  msg[i] = error_message[i + 1];
+               msg[i - 1] = '\0';
+               error_message = msg;
+            }
+
+            else
+               error_message += offset;
+         }
+
+         else
+         {
+            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
+            {
+               msg[0] = '0';
+               msg[1] = '\0';
+               error_message = msg;
+            }
+         }
+      }
+   }
+#endif
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+          error_message);
+
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, error_message);
+}
+#else
+PNG_FUNCTION(void,PNGAPI
+png_err,(png_const_structrp png_ptr),PNG_NORETURN)
+{
+   /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
+
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, "");
+}
+#endif /* ERROR_TEXT */
+
+/* Utility to safely appends strings to a buffer.  This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+    png_const_charp string)
+{
+   if (buffer != NULL && pos < bufsize)
+   {
+      if (string != NULL)
+         while (*string != '\0' && pos < bufsize-1)
+           buffer[pos++] = *string++;
+
+      buffer[pos] = '\0';
+   }
+
+   return pos;
+}
+
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+    png_alloc_size_t number)
+{
+   int count = 0;    /* number of digits output */
+   int mincount = 1; /* minimum number required */
+   int output = 0;   /* digit output (for the fixed point format) */
+
+   *--end = '\0';
+
+   /* This is written so that the loop always runs at least once, even with
+    * number zero.
+    */
+   while (end > start && (number != 0 || count < mincount))
+   {
+
+      static const char digits[] = "0123456789ABCDEF";
+
+      switch (format)
+      {
+         case PNG_NUMBER_FORMAT_fixed:
+            /* Needs five digits (the fraction) */
+            mincount = 5;
+            if (output != 0 || number % 10 != 0)
+            {
+               *--end = digits[number % 10];
+               output = 1;
+            }
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02u:
+            /* Expects at least 2 digits. */
+            mincount = 2;
+            /* FALLTHROUGH */
+
+         case PNG_NUMBER_FORMAT_u:
+            *--end = digits[number % 10];
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02x:
+            /* This format expects at least two digits */
+            mincount = 2;
+            /* FALLTHROUGH */
+
+         case PNG_NUMBER_FORMAT_x:
+            *--end = digits[number & 0xf];
+            number >>= 4;
+            break;
+
+         default: /* an error */
+            number = 0;
+            break;
+      }
+
+      /* Keep track of the number of digits added */
+      ++count;
+
+      /* Float a fixed number here: */
+      if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
+      {
+         /* End of the fraction, but maybe nothing was output?  In that case
+          * drop the decimal point.  If the number is a true zero handle that
+          * here.
+          */
+         if (output != 0)
+            *--end = '.';
+         else if (number == 0) /* and !output */
+            *--end = '0';
+      }
+   }
+
+   return end;
+}
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called whenever there is a non-fatal error.  This function
+ * should not be changed.  If there is a need to handle warnings differently,
+ * you should supply a replacement warning function and use
+ * png_set_error_fn() to replace the warning function at run-time.
+ */
+void PNGAPI
+png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+   int offset = 0;
+   if (png_ptr != NULL)
+   {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if ((png_ptr->flags &
+       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
+#endif
+      {
+         if (*warning_message == PNG_LITERAL_SHARP)
+         {
+            for (offset = 1; offset < 15; offset++)
+               if (warning_message[offset] == ' ')
+                  break;
+         }
+      }
+   }
+   if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+      (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
+          warning_message + offset);
+   else
+      png_default_warning(png_ptr, warning_message + offset);
+}
+
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter
+ * is introduced by @<number>, where 'number' starts at 1.  This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+    png_const_charp string)
+{
+   if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+      (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+    png_alloc_size_t value)
+{
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+   png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+    png_int_32 value)
+{
+   png_alloc_size_t u;
+   png_charp str;
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+
+   /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+   u = (png_alloc_size_t)value;
+   if (value < 0)
+      u = ~u + 1;
+
+   str = PNG_FORMAT_NUMBER(buffer, format, u);
+
+   if (value < 0 && str > buffer)
+      *--str = '-';
+
+   png_warning_parameter(p, number, str);
+}
+
+void
+png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
+    png_const_charp message)
+{
+   /* The internal buffer is just 192 bytes - enough for all our messages,
+    * overflow doesn't happen because this code checks!  If someone figures
+    * out how to send us a message longer than 192 bytes, all that will
+    * happen is that the message will be truncated appropriately.
+    */
+   size_t i = 0; /* Index in the msg[] buffer: */
+   char msg[192];
+
+   /* Each iteration through the following loop writes at most one character
+    * to msg[i++] then returns here to validate that there is still space for
+    * the trailing '\0'.  It may (in the case of a parameter) read more than
+    * one character from message[]; it must check for '\0' and continue to the
+    * test if it finds the end of string.
+    */
+   while (i<(sizeof msg)-1 && *message != '\0')
+   {
+      /* '@' at end of string is now just printed (previously it was skipped);
+       * it is an error in the calling code to terminate the string with @.
+       */
+      if (p != NULL && *message == '@' && message[1] != '\0')
+      {
+         int parameter_char = *++message; /* Consume the '@' */
+         static const char valid_parameters[] = "123456789";
+         int parameter = 0;
+
+         /* Search for the parameter digit, the index in the string is the
+          * parameter to use.
+          */
+         while (valid_parameters[parameter] != parameter_char &&
+            valid_parameters[parameter] != '\0')
+            ++parameter;
+
+         /* If the parameter digit is out of range it will just get printed. */
+         if (parameter < PNG_WARNING_PARAMETER_COUNT)
+         {
+            /* Append this parameter */
+            png_const_charp parm = p[parameter];
+            png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+
+            /* No need to copy the trailing '\0' here, but there is no guarantee
+             * that parm[] has been initialized, so there is no guarantee of a
+             * trailing '\0':
+             */
+            while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
+               msg[i++] = *parm++;
+
+            /* Consume the parameter digit too: */
+            ++message;
+            continue;
+         }
+
+         /* else not a parameter and there is a character after the @ sign; just
+          * copy that.  This is known not to be '\0' because of the test above.
+          */
+      }
+
+      /* At this point *message can't be '\0', even in the bad parameter case
+       * above where there is a lone '@' at the end of the message string.
+       */
+      msg[i++] = *message++;
+   }
+
+   /* i is always less than (sizeof msg), so: */
+   msg[i] = '\0';
+
+   /* And this is the formatted message. It may be larger than
+    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
+    * are not (currently) formatted.
+    */
+   png_warning(png_ptr, msg);
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_warning(png_ptr, error_message);
+         else
+#     endif
+      png_warning(png_ptr, error_message);
+   }
+
+   else
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_error(png_ptr, error_message);
+         else
+#     endif
+      png_error(png_ptr, error_message);
+   }
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
+      png_warning(png_ptr, error_message);
+   else
+      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
+      png_warning(png_ptr, error_message);
+   else
+      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+#endif /* BENIGN_ERRORS */
+
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
+/* These utilities are used internally to build an error message that relates
+ * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
+ * which is used to prefix the message.  The message is limited in length
+ * to 63 bytes. The name characters are output as hex digits wrapped in []
+ * if the character is invalid.
+ */
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+static PNG_CONST char png_digit[16] = {
+   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+   'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+static void /* PRIVATE */
+png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
+    error_message)
+{
+   png_uint_32 chunk_name = png_ptr->chunk_name;
+   int iout = 0, ishift = 24;
+
+   while (ishift >= 0)
+   {
+      int c = (int)(chunk_name >> ishift) & 0xff;
+
+      ishift -= 8;
+      if (isnonalpha(c) != 0)
+      {
+         buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
+         buffer[iout++] = png_digit[(c & 0xf0) >> 4];
+         buffer[iout++] = png_digit[c & 0x0f];
+         buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
+      }
+
+      else
+      {
+         buffer[iout++] = (char)c;
+      }
+   }
+
+   if (error_message == NULL)
+      buffer[iout] = '\0';
+
+   else
+   {
+      int iin = 0;
+
+      buffer[iout++] = ':';
+      buffer[iout++] = ' ';
+
+      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+         buffer[iout++] = error_message[iin++];
+
+      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+      buffer[iout] = '\0';
+   }
+}
+#endif /* WARNINGS || ERROR_TEXT */
+
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_FUNCTION(void,PNGAPI
+png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+      png_error(png_ptr, error_message);
+
+   else
+   {
+      png_format_buffer(png_ptr, msg, error_message);
+      png_error(png_ptr, msg);
+   }
+}
+#endif /* READ && ERROR_TEXT */
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void PNGAPI
+png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+      png_warning(png_ptr, warning_message);
+
+   else
+   {
+      png_format_buffer(png_ptr, msg, warning_message);
+      png_warning(png_ptr, msg);
+   }
+}
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+    error_message)
+{
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+      png_chunk_warning(png_ptr, error_message);
+
+   else
+      png_chunk_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+#endif
+#endif /* READ */
+
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+#  ifndef PNG_WARNINGS_SUPPORTED
+      PNG_UNUSED(message)
+#  endif
+
+   /* This is always supported, but for just read or just write it
+    * unconditionally does the right thing.
+    */
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#  endif
+
+#  ifdef PNG_READ_SUPPORTED
+      {
+         if (error < PNG_CHUNK_ERROR)
+            png_chunk_warning(png_ptr, message);
+
+         else
+            png_chunk_benign_error(png_ptr, message);
+      }
+#  endif
+
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+      {
+         if (error < PNG_CHUNK_WRITE_ERROR)
+            png_app_warning(png_ptr, message);
+
+         else
+            png_app_error(png_ptr, message);
+      }
+#  endif
+}
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_FUNCTION(void,
+png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
+{
+#  define fixed_message "fixed point overflow in "
+#  define fixed_message_ln ((sizeof fixed_message)-1)
+   unsigned int  iin;
+   char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
+   memcpy(msg, fixed_message, fixed_message_ln);
+   iin = 0;
+   if (name != NULL)
+      while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+      {
+         msg[fixed_message_ln + iin] = name[iin];
+         ++iin;
+      }
+   msg[fixed_message_ln + iin] = 0;
+   png_error(png_ptr, msg);
+}
+#endif
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
+    size_t jmp_buf_size)
+{
+   /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
+    * and it must not change after that.  Libpng doesn't care how big the
+    * buffer is, just that it doesn't change.
+    *
+    * If the buffer size is no *larger* than the size of jmp_buf when libpng is
+    * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
+    * semantics that this call will not fail.  If the size is larger, however,
+    * the buffer is allocated and this may fail, causing the function to return
+    * NULL.
+    */
+   if (png_ptr == NULL)
+      return NULL;
+
+   if (png_ptr->jmp_buf_ptr == NULL)
+   {
+      png_ptr->jmp_buf_size = 0; /* not allocated */
+
+      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
+         png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
+
+      else
+      {
+         png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
+             png_malloc_warn(png_ptr, jmp_buf_size));
+
+         if (png_ptr->jmp_buf_ptr == NULL)
+            return NULL; /* new NULL return on OOM */
+
+         png_ptr->jmp_buf_size = jmp_buf_size;
+      }
+   }
+
+   else /* Already allocated: check the size */
+   {
+      size_t size = png_ptr->jmp_buf_size;
+
+      if (size == 0)
+      {
+         size = (sizeof png_ptr->jmp_buf_local);
+         if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
+         {
+            /* This is an internal error in libpng: somehow we have been left
+             * with a stack allocated jmp_buf when the application regained
+             * control.  It's always possible to fix this up, but for the moment
+             * this is a png_error because that makes it easy to detect.
+             */
+            png_error(png_ptr, "Libpng jmp_buf still allocated");
+            /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
+         }
+      }
+
+      if (size != jmp_buf_size)
+      {
+         png_warning(png_ptr, "Application jmp_buf size changed");
+         return NULL; /* caller will probably crash: no choice here */
+      }
+   }
+
+   /* Finally fill in the function, now we have a satisfactory buffer. It is
+    * valid to change the function on every call.
+    */
+   png_ptr->longjmp_fn = longjmp_fn;
+   return png_ptr->jmp_buf_ptr;
+}
+
+void /* PRIVATE */
+png_free_jmpbuf(png_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+   {
+      jmp_buf *jb = png_ptr->jmp_buf_ptr;
+
+      /* A size of 0 is used to indicate a local, stack, allocation of the
+       * pointer; used here and in png.c
+       */
+      if (jb != NULL && png_ptr->jmp_buf_size > 0)
+      {
+
+         /* This stuff is so that a failure to free the error control structure
+          * does not leave libpng in a state with no valid error handling: the
+          * free always succeeds, if there is an error it gets ignored.
+          */
+         if (jb != &png_ptr->jmp_buf_local)
+         {
+            /* Make an internal, libpng, jmp_buf to return here */
+            jmp_buf free_jmp_buf;
+
+            if (!setjmp(free_jmp_buf))
+            {
+               png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
+               png_ptr->jmp_buf_size = 0; /* stack allocation */
+               png_ptr->longjmp_fn = longjmp;
+               png_free(png_ptr, jb); /* Return to setjmp on error */
+            }
+         }
+      }
+
+      /* *Always* cancel everything out: */
+      png_ptr->jmp_buf_size = 0;
+      png_ptr->jmp_buf_ptr = NULL;
+      png_ptr->longjmp_fn = 0;
+   }
+}
+#endif
+
+/* This is the default error handling function.  Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static PNG_FUNCTION(void /* PRIVATE */,
+png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   /* Check on NULL only added in 1.5.4 */
+   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
+   {
+      /* Strip "#nnnn " from beginning of error message. */
+      int offset;
+      char error_number[16];
+      for (offset = 0; offset<15; offset++)
+      {
+         error_number[offset] = error_message[offset + 1];
+         if (error_message[offset] == ' ')
+            break;
+      }
+
+      if ((offset > 1) && (offset < 15))
+      {
+         error_number[offset - 1] = '\0';
+         fprintf(stderr, "libpng error no. %s: %s",
+             error_number, error_message + offset + 1);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+
+      else
+      {
+         fprintf(stderr, "libpng error: %s, offset=%d",
+             error_message, offset);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+   }
+   else
+#endif
+   {
+      fprintf(stderr, "libpng error: %s", error_message ? error_message :
+         "undefined");
+      fprintf(stderr, PNG_STRING_NEWLINE);
+   }
+#else
+   PNG_UNUSED(error_message) /* Make compiler happy */
+#endif
+   png_longjmp(png_ptr, 1);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
+       png_ptr->jmp_buf_ptr != NULL)
+      png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(val)
+#endif
+
+   /* If control reaches this point, png_longjmp() must not return. The only
+    * choice is to terminate the whole process (or maybe the thread); to do
+    * this the ANSI-C abort() function is used unless a different method is
+    * implemented by overriding the default configuration setting for
+    * PNG_ABORT().
+    */
+   PNG_ABORT();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want them to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+static void /* PRIVATE */
+png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
+{
+#ifdef PNG_CONSOLE_IO_SUPPORTED
+#  ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (*warning_message == PNG_LITERAL_SHARP)
+   {
+      int offset;
+      char warning_number[16];
+      for (offset = 0; offset < 15; offset++)
+      {
+         warning_number[offset] = warning_message[offset + 1];
+         if (warning_message[offset] == ' ')
+            break;
+      }
+
+      if ((offset > 1) && (offset < 15))
+      {
+         warning_number[offset + 1] = '\0';
+         fprintf(stderr, "libpng warning no. %s: %s",
+             warning_number, warning_message + offset);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+
+      else
+      {
+         fprintf(stderr, "libpng warning: %s",
+             warning_message);
+         fprintf(stderr, PNG_STRING_NEWLINE);
+      }
+   }
+   else
+#  endif
+
+   {
+      fprintf(stderr, "libpng warning: %s", warning_message);
+      fprintf(stderr, PNG_STRING_NEWLINE);
+   }
+#else
+   PNG_UNUSED(warning_message) /* Make compiler happy */
+#endif
+   PNG_UNUSED(png_ptr) /* Make compiler happy */
+}
+#endif /* WARNINGS */
+
+/* This function is called when the application wants to use another method
+ * of handling errors and warnings.  Note that the error function MUST NOT
+ * return to the calling routine or serious problems will occur.  The return
+ * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
+ */
+void PNGAPI
+png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warning_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->error_ptr = error_ptr;
+   png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_ptr->warning_fn = warning_fn;
+#else
+   PNG_UNUSED(warning_fn)
+#endif
+}
+
+
+/* This function returns a pointer to the error_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_error_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return NULL;
+
+   return ((png_voidp)png_ptr->error_ptr);
+}
+
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->flags &=
+         ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
+         PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+   }
+}
+#endif
+
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+   /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
+    * possible to implement without setjmp support just so long as there is some
+    * way to handle the error return here:
+    */
+PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
+png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
+    PNG_NORETURN)
+{
+   const png_const_structrp png_ptr = png_nonconst_ptr;
+   png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+   /* An error is always logged here, overwriting anything (typically a warning)
+    * that is already there:
+    */
+   if (image != NULL)
+   {
+      png_safecat(image->message, (sizeof image->message), 0, error_message);
+      image->warning_or_error |= PNG_IMAGE_ERROR;
+
+      /* Retrieve the jmp_buf from within the png_control, making this work for
+       * C++ compilation too is pretty tricky: C++ wants a pointer to the first
+       * element of a jmp_buf, but C doesn't tell us the type of that.
+       */
+      if (image->opaque != NULL && image->opaque->error_buf != NULL)
+         longjmp(png_control_jmp_buf(image->opaque), 1);
+
+      /* Missing longjmp buffer, the following is to help debugging: */
+      {
+         size_t pos = png_safecat(image->message, (sizeof image->message), 0,
+             "bad longjmp: ");
+         png_safecat(image->message, (sizeof image->message), pos,
+             error_message);
+      }
+   }
+
+   /* Here on an internal programming error. */
+   abort();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void /* PRIVATE */ PNGCBAPI
+png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
+{
+   const png_const_structrp png_ptr = png_nonconst_ptr;
+   png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+   /* A warning is only logged if there is no prior warning or error. */
+   if (image->warning_or_error == 0)
+   {
+      png_safecat(image->message, (sizeof image->message), 0, warning_message);
+      image->warning_or_error |= PNG_IMAGE_WARNING;
+   }
+}
+#endif
+
+int /* PRIVATE */
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
+{
+   volatile png_imagep image = image_in;
+   volatile int result;
+   volatile png_voidp saved_error_buf;
+   jmp_buf safe_jmpbuf;
+
+   /* Safely execute function(arg) with png_error returning to this function. */
+   saved_error_buf = image->opaque->error_buf;
+   result = setjmp(safe_jmpbuf) == 0;
+
+   if (result != 0)
+   {
+
+      image->opaque->error_buf = safe_jmpbuf;
+      result = function(arg);
+   }
+
+   image->opaque->error_buf = saved_error_buf;
+
+   /* And do the cleanup prior to any failure return. */
+   if (result == 0)
+      png_image_free(image);
+
+   return result;
+}
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
+#endif /* READ || WRITE */
diff --git a/xs/src/png/libpng/pngget.c b/xs/src/png/libpng/pngget.c
new file mode 100644
index 000000000..26e9fb1c3
--- /dev/null
+++ b/xs/src/png/libpng/pngget.c
@@ -0,0 +1,1248 @@
+
+/* pngget.c - retrieval of values from info struct
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+png_uint_32 PNGAPI
+png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32 flag)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->valid & flag);
+
+   return(0);
+}
+
+png_size_t PNGAPI
+png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->rowbytes);
+
+   return(0);
+}
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+png_bytepp PNGAPI
+png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->row_pointers);
+
+   return(0);
+}
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+/* Easy access to info, added in libpng-0.99 */
+png_uint_32 PNGAPI
+png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->width;
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->height;
+
+   return (0);
+}
+
+png_byte PNGAPI
+png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->bit_depth;
+
+   return (0);
+}
+
+png_byte PNGAPI
+png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->color_type;
+
+   return (0);
+}
+
+png_byte PNGAPI
+png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->filter_type;
+
+   return (0);
+}
+
+png_byte PNGAPI
+png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->interlace_type;
+
+   return (0);
+}
+
+png_byte PNGAPI
+png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return info_ptr->compression_type;
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
+      {
+         png_debug1(1, "in %s retrieval function",
+             "png_get_x_pixels_per_meter");
+
+         if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+            return (info_ptr->x_pixels_per_unit);
+      }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+    info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function",
+          "png_get_y_pixels_per_meter");
+
+      if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
+         return (info_ptr->y_pixels_per_unit);
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
+
+      if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
+          info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
+         return (info_ptr->x_pixels_per_unit);
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
+
+      if (info_ptr->x_pixels_per_unit != 0)
+         return ((float)((float)info_ptr->y_pixels_per_unit
+             /(float)info_ptr->x_pixels_per_unit));
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return ((float)0.0);
+}
+#endif
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
+    png_const_inforp info_ptr)
+{
+#ifdef PNG_READ_pHYs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0 &&
+       info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 &&
+       info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX &&
+       info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
+   {
+      png_fixed_point res;
+
+      png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed");
+
+      /* The following casts work because a PNG 4 byte integer only has a valid
+       * range of 0..2^31-1; otherwise the cast might overflow.
+       */
+      if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
+          (png_int_32)info_ptr->x_pixels_per_unit) != 0)
+         return res;
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return 0;
+}
+#endif
+
+png_int_32 PNGAPI
+png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
+
+      if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+         return (info_ptr->x_offset);
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
+
+      if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
+         return (info_ptr->y_offset);
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+png_int_32 PNGAPI
+png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
+
+      if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+         return (info_ptr->x_offset);
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+png_int_32 PNGAPI
+png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+#ifdef PNG_oFFs_SUPPORTED
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
+
+      if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
+         return (info_ptr->y_offset);
+   }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
+#endif
+
+   return (0);
+}
+
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+static png_uint_32
+ppi_from_ppm(png_uint_32 ppm)
+{
+#if 0
+   /* The conversion is *(2.54/100), in binary (32 digits):
+    * .00000110100000001001110101001001
+    */
+   png_uint_32 t1001, t1101;
+   ppm >>= 1;                  /* .1 */
+   t1001 = ppm + (ppm >> 3);   /* .1001 */
+   t1101 = t1001 + (ppm >> 1); /* .1101 */
+   ppm >>= 20;                 /* .000000000000000000001 */
+   t1101 += t1101 >> 15;       /* .1101000000000001101 */
+   t1001 >>= 11;               /* .000000000001001 */
+   t1001 += t1001 >> 12;       /* .000000000001001000000001001 */
+   ppm += t1001;               /* .000000000001001000001001001 */
+   ppm += t1101;               /* .110100000001001110101001001 */
+   return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
+#else
+   /* The argument is a PNG unsigned integer, so it is not permitted
+    * to be bigger than 2^31.
+    */
+   png_fixed_point result;
+   if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
+       5000) != 0)
+      return (png_uint_32)result;
+
+   /* Overflow. */
+   return 0;
+#endif
+}
+
+png_uint_32 PNGAPI
+png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
+}
+
+png_uint_32 PNGAPI
+png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
+}
+
+png_uint_32 PNGAPI
+png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
+}
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+static png_fixed_point
+png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
+{
+   /* Convert from metres * 1,000,000 to inches * 100,000, meters to
+    * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
+    * Notice that this can overflow - a warning is output and 0 is
+    * returned.
+    */
+   return png_muldiv_warn(png_ptr, microns, 500, 127);
+}
+
+png_fixed_point PNGAPI
+png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
+    png_const_inforp info_ptr)
+{
+   return png_fixed_inches_from_microns(png_ptr,
+       png_get_x_offset_microns(png_ptr, info_ptr));
+}
+#endif
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_fixed_point PNGAPI
+png_get_y_offset_inches_fixed(png_const_structrp png_ptr,
+    png_const_inforp info_ptr)
+{
+   return png_fixed_inches_from_microns(png_ptr,
+       png_get_y_offset_microns(png_ptr, info_ptr));
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   /* To avoid the overflow do the conversion directly in floating
+    * point.
+    */
+   return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
+png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   /* To avoid the overflow do the conversion directly in floating
+    * point.
+    */
+   return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
+}
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+   png_uint_32 retval = 0;
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "pHYs");
+
+      if (res_x != NULL)
+      {
+         *res_x = info_ptr->x_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+
+      if (res_y != NULL)
+      {
+         *res_y = info_ptr->y_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+
+      if (unit_type != NULL)
+      {
+         *unit_type = (int)info_ptr->phys_unit_type;
+         retval |= PNG_INFO_pHYs;
+
+         if (*unit_type == 1)
+         {
+            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
+         }
+      }
+   }
+
+   return (retval);
+}
+#endif /* pHYs */
+#endif /* INCH_CONVERSIONS */
+
+/* png_get_channels really belongs in here, too, but it's been around longer */
+
+#endif /* EASY_ACCESS */
+
+
+png_byte PNGAPI
+png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->channels);
+
+   return (0);
+}
+
+#ifdef PNG_READ_SUPPORTED
+png_const_bytep PNGAPI
+png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->signature);
+
+   return (NULL);
+}
+#endif
+
+#ifdef PNG_bKGD_SUPPORTED
+png_uint_32 PNGAPI
+png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_color_16p *background)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
+       background != NULL)
+   {
+      png_debug1(1, "in %s retrieval function", "bKGD");
+
+      *background = &(info_ptr->background);
+      return (PNG_INFO_bKGD);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+/* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
+ * same time to correct the rgb grayscale coefficient defaults obtained from the
+ * cHRM chunk in 1.5.4
+ */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    double *white_x, double *white_y, double *red_x, double *red_y,
+    double *green_x, double *green_y, double *blue_x, double *blue_y)
+{
+   /* Quiet API change: this code used to only return the end points if a cHRM
+    * chunk was present, but the end points can also come from iCCP or sRGB
+    * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
+    * the png_set_ APIs merely check that set end points are mutually
+    * consistent.
+    */
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "cHRM");
+
+      if (white_x != NULL)
+         *white_x = png_float(png_ptr,
+             info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
+      if (white_y != NULL)
+         *white_y = png_float(png_ptr,
+             info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
+      if (red_x != NULL)
+         *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
+             "cHRM red X");
+      if (red_y != NULL)
+         *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
+             "cHRM red Y");
+      if (green_x != NULL)
+         *green_x = png_float(png_ptr,
+             info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
+      if (green_y != NULL)
+         *green_y = png_float(png_ptr,
+             info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
+      if (blue_x != NULL)
+         *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
+             "cHRM blue X");
+      if (blue_y != NULL)
+         *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
+             "cHRM blue Y");
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    double *red_X, double *red_Y, double *red_Z, double *green_X,
+    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
+    double *blue_Z)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
+
+      if (red_X != NULL)
+         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
+             "cHRM red X");
+      if (red_Y != NULL)
+         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
+             "cHRM red Y");
+      if (red_Z != NULL)
+         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
+             "cHRM red Z");
+      if (green_X != NULL)
+         *green_X = png_float(png_ptr,
+             info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
+      if (green_Y != NULL)
+         *green_Y = png_float(png_ptr,
+             info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
+      if (green_Z != NULL)
+         *green_Z = png_float(png_ptr,
+             info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
+      if (blue_X != NULL)
+         *blue_X = png_float(png_ptr,
+             info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
+      if (blue_Y != NULL)
+         *blue_Y = png_float(png_ptr,
+             info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
+      if (blue_Z != NULL)
+         *blue_Z = png_float(png_ptr,
+             info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
+#  endif
+
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+
+      if (int_red_X != NULL)
+         *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
+      if (int_red_Y != NULL)
+         *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
+      if (int_red_Z != NULL)
+         *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
+      if (int_green_X != NULL)
+         *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
+      if (int_green_Y != NULL)
+         *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
+      if (int_green_Z != NULL)
+         *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
+      if (int_blue_X != NULL)
+         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
+      if (int_blue_Y != NULL)
+         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
+      if (int_blue_Z != NULL)
+         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+    png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+    png_fixed_point *blue_x, png_fixed_point *blue_y)
+{
+   png_debug1(1, "in %s retrieval function", "cHRM");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      if (white_x != NULL)
+         *white_x = info_ptr->colorspace.end_points_xy.whitex;
+      if (white_y != NULL)
+         *white_y = info_ptr->colorspace.end_points_xy.whitey;
+      if (red_x != NULL)
+         *red_x = info_ptr->colorspace.end_points_xy.redx;
+      if (red_y != NULL)
+         *red_y = info_ptr->colorspace.end_points_xy.redy;
+      if (green_x != NULL)
+         *green_x = info_ptr->colorspace.end_points_xy.greenx;
+      if (green_y != NULL)
+         *green_y = info_ptr->colorspace.end_points_xy.greeny;
+      if (blue_x != NULL)
+         *blue_x = info_ptr->colorspace.end_points_xy.bluex;
+      if (blue_y != NULL)
+         *blue_y = info_ptr->colorspace.end_points_xy.bluey;
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
+#  endif
+#endif
+
+#ifdef PNG_gAMA_SUPPORTED
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *file_gamma)
+{
+   png_debug1(1, "in %s retrieval function", "gAMA");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+       file_gamma != NULL)
+   {
+      *file_gamma = info_ptr->colorspace.gamma;
+      return (PNG_INFO_gAMA);
+   }
+
+   return (0);
+}
+#  endif
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    double *file_gamma)
+{
+   png_debug1(1, "in %s retrieval function", "gAMA(float)");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+      file_gamma != NULL)
+   {
+      *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
+          "png_get_gAMA");
+      return (PNG_INFO_gAMA);
+   }
+
+   return (0);
+}
+#  endif
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    int *file_srgb_intent)
+{
+   png_debug1(1, "in %s retrieval function", "sRGB");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL)
+   {
+      *file_srgb_intent = info_ptr->colorspace.rendering_intent;
+      return (PNG_INFO_sRGB);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+png_uint_32 PNGAPI
+png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_charpp name, int *compression_type,
+    png_bytepp profile, png_uint_32 *proflen)
+{
+   png_debug1(1, "in %s retrieval function", "iCCP");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_iCCP) != 0 &&
+       name != NULL && compression_type != NULL && profile != NULL &&
+           proflen != NULL)
+   {
+      *name = info_ptr->iccp_name;
+      *profile = info_ptr->iccp_profile;
+      *proflen = png_get_uint_32(info_ptr->iccp_profile);
+      /* This is somewhat irrelevant since the profile data returned has
+       * actually been uncompressed.
+       */
+      *compression_type = PNG_COMPRESSION_TYPE_BASE;
+      return (PNG_INFO_iCCP);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+int PNGAPI
+png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_sPLT_tpp spalettes)
+{
+   if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+   {
+      *spalettes = info_ptr->splt_palettes;
+      return info_ptr->splt_palettes_num;
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+png_uint_32 PNGAPI
+png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_bytep *exif)
+{
+  png_warning(png_ptr, "png_get_eXIf does not work; use png_get_eXIf_1");
+  PNG_UNUSED(info_ptr)
+  PNG_UNUSED(exif)
+  return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_eXIf_1(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32 *num_exif, png_bytep *exif)
+{
+   png_debug1(1, "in %s retrieval function", "eXIf");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_eXIf) != 0 && exif != NULL)
+   {
+      *num_exif = info_ptr->num_exif;
+      *exif = info_ptr->exif;
+      return (PNG_INFO_eXIf);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+png_uint_32 PNGAPI
+png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_uint_16p *hist)
+{
+   png_debug1(1, "in %s retrieval function", "hIST");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL)
+   {
+      *hist = info_ptr->hist;
+      return (PNG_INFO_hIST);
+   }
+
+   return (0);
+}
+#endif
+
+png_uint_32 PNGAPI
+png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32 *width, png_uint_32 *height, int *bit_depth,
+    int *color_type, int *interlace_type, int *compression_type,
+    int *filter_type)
+{
+   png_debug1(1, "in %s retrieval function", "IHDR");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return (0);
+
+   if (width != NULL)
+       *width = info_ptr->width;
+
+   if (height != NULL)
+       *height = info_ptr->height;
+
+   if (bit_depth != NULL)
+       *bit_depth = info_ptr->bit_depth;
+
+   if (color_type != NULL)
+       *color_type = info_ptr->color_type;
+
+   if (compression_type != NULL)
+      *compression_type = info_ptr->compression_type;
+
+   if (filter_type != NULL)
+      *filter_type = info_ptr->filter_type;
+
+   if (interlace_type != NULL)
+      *interlace_type = info_ptr->interlace_type;
+
+   /* This is redundant if we can be sure that the info_ptr values were all
+    * assigned in png_set_IHDR().  We do the check anyhow in case an
+    * application has ignored our advice not to mess with the members
+    * of info_ptr directly.
+    */
+   png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+       info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+       info_ptr->compression_type, info_ptr->filter_type);
+
+   return (1);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
+{
+   png_debug1(1, "in %s retrieval function", "oFFs");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0 &&
+       offset_x != NULL && offset_y != NULL && unit_type != NULL)
+   {
+      *offset_x = info_ptr->x_offset;
+      *offset_y = info_ptr->y_offset;
+      *unit_type = (int)info_ptr->offset_unit_type;
+      return (PNG_INFO_oFFs);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
+    png_charp *units, png_charpp *params)
+{
+   png_debug1(1, "in %s retrieval function", "pCAL");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pCAL) != 0 &&
+       purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+       nparams != NULL && units != NULL && params != NULL)
+   {
+      *purpose = info_ptr->pcal_purpose;
+      *X0 = info_ptr->pcal_X0;
+      *X1 = info_ptr->pcal_X1;
+      *type = (int)info_ptr->pcal_type;
+      *nparams = (int)info_ptr->pcal_nparams;
+      *units = info_ptr->pcal_units;
+      *params = info_ptr->pcal_params;
+      return (PNG_INFO_pCAL);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+#    if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+         defined(PNG_FLOATING_POINT_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    int *unit, png_fixed_point *width, png_fixed_point *height)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
+   {
+      *unit = info_ptr->scal_unit;
+      /*TODO: make this work without FP support; the API is currently eliminated
+       * if neither floating point APIs nor internal floating point arithmetic
+       * are enabled.
+       */
+      *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
+      *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
+          "sCAL height");
+      return (PNG_INFO_sCAL);
+   }
+
+   return(0);
+}
+#    endif /* FLOATING_ARITHMETIC */
+#  endif /* FIXED_POINT */
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    int *unit, double *width, double *height)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
+   {
+      *unit = info_ptr->scal_unit;
+      *width = atof(info_ptr->scal_s_width);
+      *height = atof(info_ptr->scal_s_height);
+      return (PNG_INFO_sCAL);
+   }
+
+   return(0);
+}
+#  endif /* FLOATING POINT */
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    int *unit, png_charpp width, png_charpp height)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
+   {
+      *unit = info_ptr->scal_unit;
+      *width = info_ptr->scal_s_width;
+      *height = info_ptr->scal_s_height;
+      return (PNG_INFO_sCAL);
+   }
+
+   return(0);
+}
+#endif /* sCAL */
+
+#ifdef PNG_pHYs_SUPPORTED
+png_uint_32 PNGAPI
+png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
+{
+   png_uint_32 retval = 0;
+
+   png_debug1(1, "in %s retrieval function", "pHYs");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
+   {
+      if (res_x != NULL)
+      {
+         *res_x = info_ptr->x_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+
+      if (res_y != NULL)
+      {
+         *res_y = info_ptr->y_pixels_per_unit;
+         retval |= PNG_INFO_pHYs;
+      }
+
+      if (unit_type != NULL)
+      {
+         *unit_type = (int)info_ptr->phys_unit_type;
+         retval |= PNG_INFO_pHYs;
+      }
+   }
+
+   return (retval);
+}
+#endif /* pHYs */
+
+png_uint_32 PNGAPI
+png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_colorp *palette, int *num_palette)
+{
+   png_debug1(1, "in %s retrieval function", "PLTE");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL)
+   {
+      *palette = info_ptr->palette;
+      *num_palette = info_ptr->num_palette;
+      png_debug1(3, "num_palette = %d", *num_palette);
+      return (PNG_INFO_PLTE);
+   }
+
+   return (0);
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_color_8p *sig_bit)
+{
+   png_debug1(1, "in %s retrieval function", "sBIT");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL)
+   {
+      *sig_bit = &(info_ptr->sig_bit);
+      return (PNG_INFO_sBIT);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+int PNGAPI
+png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_textp *text_ptr, int *num_text)
+{
+   if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
+   {
+      png_debug1(1, "in 0x%lx retrieval function",
+         (unsigned long)png_ptr->chunk_name);
+
+      if (text_ptr != NULL)
+         *text_ptr = info_ptr->text;
+
+      if (num_text != NULL)
+         *num_text = info_ptr->num_text;
+
+      return info_ptr->num_text;
+   }
+
+   if (num_text != NULL)
+      *num_text = 0;
+
+   return(0);
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_timep *mod_time)
+{
+   png_debug1(1, "in %s retrieval function", "tIME");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL)
+   {
+      *mod_time = &(info_ptr->mod_time);
+      return (PNG_INFO_tIME);
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
+{
+   png_uint_32 retval = 0;
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_tRNS) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "tRNS");
+
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (trans_alpha != NULL)
+         {
+            *trans_alpha = info_ptr->trans_alpha;
+            retval |= PNG_INFO_tRNS;
+         }
+
+         if (trans_color != NULL)
+            *trans_color = &(info_ptr->trans_color);
+      }
+
+      else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
+      {
+         if (trans_color != NULL)
+         {
+            *trans_color = &(info_ptr->trans_color);
+            retval |= PNG_INFO_tRNS;
+         }
+
+         if (trans_alpha != NULL)
+            *trans_alpha = NULL;
+      }
+
+      if (num_trans != NULL)
+      {
+         *num_trans = info_ptr->num_trans;
+         retval |= PNG_INFO_tRNS;
+      }
+   }
+
+   return (retval);
+}
+#endif
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+int PNGAPI
+png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_unknown_chunkpp unknowns)
+{
+   if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+   {
+      *unknowns = info_ptr->unknown_chunks;
+      return info_ptr->unknown_chunks_num;
+   }
+
+   return (0);
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_const_structrp png_ptr)
+{
+   return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_const_structrp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+png_size_t PNGAPI
+png_get_compression_buffer_size(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return 0;
+
+#ifdef PNG_WRITE_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#endif
+   {
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+      return png_ptr->IDAT_read_size;
+#else
+      return PNG_IDAT_READ_SIZE;
+#endif
+   }
+
+#ifdef PNG_WRITE_SUPPORTED
+   else
+      return png_ptr->zbuffer_size;
+#endif
+}
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* These functions were added to libpng 1.2.6 and were enabled
+ * by default in libpng-1.4.0 */
+png_uint_32 PNGAPI
+png_get_user_width_max (png_const_structrp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_width_max : 0);
+}
+
+png_uint_32 PNGAPI
+png_get_user_height_max (png_const_structrp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_height_max : 0);
+}
+
+/* This function was added to libpng 1.4.0 */
+png_uint_32 PNGAPI
+png_get_chunk_cache_max (png_const_structrp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
+}
+
+/* This function was added to libpng 1.4.1 */
+png_alloc_size_t PNGAPI
+png_get_chunk_malloc_max (png_const_structrp png_ptr)
+{
+   return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
+}
+#endif /* SET_USER_LIMITS */
+
+/* These functions were added to libpng 1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_io_state (png_const_structrp png_ptr)
+{
+   return png_ptr->io_state;
+}
+
+png_uint_32 PNGAPI
+png_get_io_chunk_type (png_const_structrp png_ptr)
+{
+   return png_ptr->chunk_name;
+}
+#endif /* IO_STATE */
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+int PNGAPI
+png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return png_ptr->num_palette_max;
+
+   return (-1);
+}
+#  endif
+#endif
+
+#endif /* READ || WRITE */
diff --git a/xs/src/png/libpng/pnginfo.h b/xs/src/png/libpng/pnginfo.h
new file mode 100644
index 000000000..d5f6149db
--- /dev/null
+++ b/xs/src/png/libpng/pnginfo.h
@@ -0,0 +1,267 @@
+
+/* pnginfo.h - header file for PNG reference library
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Copyright (c) 1998-2002,2004,2006-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+ /* png_info is a structure that holds the information in a PNG file so
+ * that the application can find out the characteristics of the image.
+ * If you are reading the file, this structure will tell you what is
+ * in the PNG file.  If you are writing the file, fill in the information
+ * you want to put into the PNG file, using png_set_*() functions, then
+ * call png_write_info().
+ *
+ * The names chosen should be very close to the PNG specification, so
+ * consult that document for information about the meaning of each field.
+ *
+ * With libpng < 0.95, it was only possible to directly set and read the
+ * the values in the png_info_struct, which meant that the contents and
+ * order of the values had to remain fixed.  With libpng 0.95 and later,
+ * however, there are now functions that abstract the contents of
+ * png_info_struct from the application, so this makes it easier to use
+ * libpng with dynamic libraries, and even makes it possible to use
+ * libraries that don't have all of the libpng ancillary chunk-handing
+ * functionality.  In libpng-1.5.0 this was moved into a separate private
+ * file that is not visible to applications.
+ *
+ * The following members may have allocated storage attached that should be
+ * cleaned up before the structure is discarded: palette, trans, text,
+ * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
+ * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
+ * are automatically freed when the info structure is deallocated, if they were
+ * allocated internally by libpng.  This behavior can be changed by means
+ * of the png_data_freer() function.
+ *
+ * More allocation details: all the chunk-reading functions that
+ * change these members go through the corresponding png_set_*
+ * functions.  A function to clear these members is available: see
+ * png_free_data().  The png_set_* functions do not depend on being
+ * able to point info structure members to any of the storage they are
+ * passed (they make their own copies), EXCEPT that the png_set_text
+ * functions use the same storage passed to them in the text_ptr or
+ * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
+ * functions do not make their own copies.
+ */
+#ifndef PNGINFO_H
+#define PNGINFO_H
+
+struct png_info_def
+{
+   /* The following are necessary for every PNG file */
+   png_uint_32 width;  /* width of image in pixels (from IHDR) */
+   png_uint_32 height; /* height of image in pixels (from IHDR) */
+   png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
+   png_size_t rowbytes; /* bytes needed to hold an untransformed row */
+   png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
+   png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
+   png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
+   png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
+   png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
+   /* The following three should have been named *_method not *_type */
+   png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
+   png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
+   png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+
+   /* The following are set by png_set_IHDR, called from the application on
+    * write, but the are never actually used by the write code.
+    */
+   png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
+   png_byte pixel_depth;    /* number of bits per pixel */
+   png_byte spare_byte;     /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+   /* This is never set during write */
+   png_byte signature[8];   /* magic bytes read by libpng from start of file */
+#endif
+
+   /* The rest of the data is optional.  If you are reading, check the
+    * valid field to see if the information in these are valid.  If you
+    * are writing, set the valid field to those chunks you want written,
+    * and initialize the appropriate fields below.
+    */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
+    * defined.  When COLORSPACE is switched on all the colorspace-defining
+    * chunks should be enabled, when GAMMA is switched on all the gamma-defining
+    * chunks should be enabled.  If this is not done it becomes possible to read
+    * inconsistent PNG files and assign a probably incorrect interpretation to
+    * the information.  (In other words, by carefully choosing which chunks to
+    * recognize the system configuration can select an interpretation for PNG
+    * files containing ambiguous data and this will result in inconsistent
+    * behavior between different libpng builds!)
+    */
+   png_colorspace colorspace;
+#endif
+
+#ifdef PNG_iCCP_SUPPORTED
+   /* iCCP chunk data. */
+   png_charp iccp_name;     /* profile name */
+   png_bytep iccp_profile;  /* International Color Consortium profile data */
+   png_uint_32 iccp_proflen;  /* ICC profile data length */
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+   /* The tEXt, and zTXt chunks contain human-readable textual data in
+    * uncompressed, compressed, and optionally compressed forms, respectively.
+    * The data in "text" is an array of pointers to uncompressed,
+    * null-terminated C strings. Each chunk has a keyword that describes the
+    * textual data contained in that chunk.  Keywords are not required to be
+    * unique, and the text string may be empty.  Any number of text chunks may
+    * be in an image.
+    */
+   int num_text; /* number of comments read or comments to write */
+   int max_text; /* current size of text array */
+   png_textp text; /* array of comments read or comments to write */
+#endif /* TEXT */
+
+#ifdef PNG_tIME_SUPPORTED
+   /* The tIME chunk holds the last time the displayed image data was
+    * modified.  See the png_time struct for the contents of this struct.
+    */
+   png_time mod_time;
+#endif
+
+#ifdef PNG_sBIT_SUPPORTED
+   /* The sBIT chunk specifies the number of significant high-order bits
+    * in the pixel data.  Values are in the range [1, bit_depth], and are
+    * only specified for the channels in the pixel data.  The contents of
+    * the low-order bits is not specified.  Data is valid if
+    * (valid & PNG_INFO_sBIT) is non-zero.
+    */
+   png_color_8 sig_bit; /* significant bits in color channels */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
+defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* The tRNS chunk supplies transparency data for paletted images and
+    * other image types that don't need a full alpha channel.  There are
+    * "num_trans" transparency values for a paletted image, stored in the
+    * same order as the palette colors, starting from index 0.  Values
+    * for the data are in the range [0, 255], ranging from fully transparent
+    * to fully opaque, respectively.  For non-paletted images, there is a
+    * single color specified that should be treated as fully transparent.
+    * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
+    */
+   png_bytep trans_alpha;    /* alpha values for paletted image */
+   png_color_16 trans_color; /* transparent color for non-palette image */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* The bKGD chunk gives the suggested image background color if the
+    * display program does not have its own background color and the image
+    * is needs to composited onto a background before display.  The colors
+    * in "background" are normally in the same color space/depth as the
+    * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
+    */
+   png_color_16 background;
+#endif
+
+#ifdef PNG_oFFs_SUPPORTED
+   /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
+    * and downwards from the top-left corner of the display, page, or other
+    * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
+    * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
+    */
+   png_int_32 x_offset; /* x offset on page */
+   png_int_32 y_offset; /* y offset on page */
+   png_byte offset_unit_type; /* offset units type */
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+   /* The pHYs chunk gives the physical pixel density of the image for
+    * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
+    * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
+    */
+   png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
+   png_uint_32 y_pixels_per_unit; /* vertical pixel density */
+   png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
+#endif
+
+#ifdef PNG_eXIf_SUPPORTED
+   int num_exif;  /* Added at libpng-1.6.31 */
+   png_bytep exif;
+# ifdef PNG_READ_eXIf_SUPPORTED
+   png_bytep eXIf_buf;  /* Added at libpng-1.6.32 */
+# endif
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+   /* The hIST chunk contains the relative frequency or importance of the
+    * various palette entries, so that a viewer can intelligently select a
+    * reduced-color palette, if required.  Data is an array of "num_palette"
+    * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
+    * is non-zero.
+    */
+   png_uint_16p hist;
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+   /* The pCAL chunk describes a transformation between the stored pixel
+    * values and original physical data values used to create the image.
+    * The integer range [0, 2^bit_depth - 1] maps to the floating-point
+    * range given by [pcal_X0, pcal_X1], and are further transformed by a
+    * (possibly non-linear) transformation function given by "pcal_type"
+    * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
+    * defines below, and the PNG-Group's PNG extensions document for a
+    * complete description of the transformations and how they should be
+    * implemented, and for a description of the ASCII parameter strings.
+    * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
+    */
+   png_charp pcal_purpose;  /* pCAL chunk description string */
+   png_int_32 pcal_X0;      /* minimum value */
+   png_int_32 pcal_X1;      /* maximum value */
+   png_charp pcal_units;    /* Latin-1 string giving physical units */
+   png_charpp pcal_params;  /* ASCII strings containing parameter values */
+   png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
+   png_byte pcal_nparams;   /* number of parameters given in pcal_params */
+#endif
+
+/* New members added in libpng-1.0.6 */
+   png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+   /* Storage for unknown chunks that the library doesn't recognize. */
+   png_unknown_chunkp unknown_chunks;
+
+   /* The type of this field is limited by the type of
+    * png_struct::user_chunk_cache_max, else overflow can occur.
+    */
+   int                unknown_chunks_num;
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+   /* Data on sPLT chunks (there may be more than one). */
+   png_sPLT_tp splt_palettes;
+   int         splt_palettes_num; /* Match type returned by png_get API */
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+   /* The sCAL chunk describes the actual physical dimensions of the
+    * subject matter of the graphic.  The chunk contains a unit specification
+    * a byte value, and two ASCII strings representing floating-point
+    * values.  The values are width and height corresponsing to one pixel
+    * in the image.  Data values are valid if (valid & PNG_INFO_sCAL) is
+    * non-zero.
+    */
+   png_byte scal_unit;         /* unit of physical scale */
+   png_charp scal_s_width;     /* string containing height */
+   png_charp scal_s_height;    /* string containing width */
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+   /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS)
+      non-zero */
+   /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
+   png_bytepp row_pointers;        /* the image bits */
+#endif
+
+};
+#endif /* PNGINFO_H */
diff --git a/xs/src/png/libpng/pngmem.c b/xs/src/png/libpng/pngmem.c
new file mode 100644
index 000000000..ff3ef7e88
--- /dev/null
+++ b/xs/src/png/libpng/pngmem.c
@@ -0,0 +1,284 @@
+
+/* pngmem.c - stub functions for memory allocation
+ *
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all memory allocation.  Users who
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Free a png_struct */
+void /* PRIVATE */
+png_destroy_png_struct(png_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+   {
+      /* png_free might call png_error and may certainly call
+       * png_get_mem_ptr, so fake a temporary png_struct to support this.
+       */
+      png_struct dummy_struct = *png_ptr;
+      memset(png_ptr, 0, (sizeof *png_ptr));
+      png_free(&dummy_struct, png_ptr);
+
+#     ifdef PNG_SETJMP_SUPPORTED
+         /* We may have a jmp_buf left to deallocate. */
+         png_free_jmpbuf(&dummy_struct);
+#     endif
+   }
+}
+
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more than 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information.  zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
+   ret = png_malloc(png_ptr, size);
+
+   if (ret != NULL)
+      memset(ret, 0, size);
+
+   return ret;
+}
+
+/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
+ * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
+ * Checking and error handling must happen outside this routine; it returns NULL
+ * if the allocation cannot be done (for any reason.)
+ */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED)
+{
+   /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+    * allocators have also been removed in 1.6.0, so any 16-bit system now has
+    * to implement a user memory handler.  This checks to be sure it isn't
+    * called with big numbers.
+    */
+#ifndef PNG_USER_MEM_SUPPORTED
+   PNG_UNUSED(png_ptr)
+#endif
+
+   /* Some compilers complain that this is always true.  However, it
+    * can be false when integer overflow happens.
+    */
+   if (size > 0 && size <= PNG_SIZE_MAX
+#     ifdef PNG_MAX_MALLOC_64K
+         && size <= 65536U
+#     endif
+      )
+   {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+         return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
+
+      else
+#endif
+         return malloc((size_t)size); /* checked for truncation above */
+   }
+
+   else
+      return NULL;
+}
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+    size_t element_size)
+{
+   png_alloc_size_t req = (png_alloc_size_t)nelements; /* known to be > 0 */
+
+   if (req <= PNG_SIZE_MAX/element_size)
+      return png_malloc_base(png_ptr, req * element_size);
+
+   /* The failure case when the request is too large */
+   return NULL;
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+    size_t element_size),PNG_ALLOCATED)
+{
+   if (nelements <= 0 || element_size == 0)
+      png_error(png_ptr, "internal error: array alloc");
+
+   return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+    int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+   /* These are internal errors: */
+   if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+      (old_array == NULL && old_elements > 0))
+      png_error(png_ptr, "internal error: array realloc");
+
+   /* Check for overflow on the elements count (so the caller does not have to
+    * check.)
+    */
+   if (add_elements <= INT_MAX - old_elements)
+   {
+      png_voidp new_array = png_malloc_array_checked(png_ptr,
+          old_elements+add_elements, element_size);
+
+      if (new_array != NULL)
+      {
+         /* Because png_malloc_array worked the size calculations below cannot
+          * overflow.
+          */
+         if (old_elements > 0)
+            memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+         memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+             element_size*(unsigned)add_elements);
+
+         return new_array;
+      }
+   }
+
+   return NULL; /* error */
+}
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
+
+/* Various functions that have different error handling are derived from this.
+ * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
+ * function png_malloc_default is also provided.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   ret = png_malloc_base(png_ptr, size);
+
+   if (ret == NULL)
+       png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+
+   return ret;
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED PNG_DEPRECATED)
+{
+   png_voidp ret;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   /* Passing 'NULL' here bypasses the application provided memory handler. */
+   ret = png_malloc_base(NULL/*use malloc*/, size);
+
+   if (ret == NULL)
+      png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
+
+   return ret;
+}
+#endif /* USER_MEM */
+
+/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
+ * function will issue a png_warning and return NULL instead of issuing a
+ * png_error, if it fails to allocate the requested memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
+    PNG_ALLOCATED)
+{
+   if (png_ptr != NULL)
+   {
+      png_voidp ret = png_malloc_base(png_ptr, size);
+
+      if (ret != NULL)
+         return ret;
+
+      png_warning(png_ptr, "Out of memory");
+   }
+
+   return NULL;
+}
+
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_const_structrp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+      png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
+
+   else
+      png_free_default(png_ptr, ptr);
+}
+
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+#endif /* USER_MEM */
+
+   free(ptr);
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+  malloc_fn, png_free_ptr free_fn)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->mem_ptr = mem_ptr;
+      png_ptr->malloc_fn = malloc_fn;
+      png_ptr->free_fn = free_fn;
+   }
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return NULL;
+
+   return png_ptr->mem_ptr;
+}
+#endif /* USER_MEM */
+#endif /* READ || WRITE */
diff --git a/xs/src/png/libpng/pngpread.c b/xs/src/png/libpng/pngpread.c
new file mode 100644
index 000000000..fbe361dc3
--- /dev/null
+++ b/xs/src/png/libpng/pngpread.c
@@ -0,0 +1,1096 @@
+
+/* pngpread.c - read a png file in push mode
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+
+/* Push model modes */
+#define PNG_READ_SIG_MODE   0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE  2
+#define PNG_READ_tEXt_MODE  4
+#define PNG_READ_zTXt_MODE  5
+#define PNG_READ_DONE_MODE  6
+#define PNG_READ_iTXt_MODE  7
+#define PNG_ERROR_MODE      8
+
+#define PNG_PUSH_SAVE_BUFFER_IF_FULL \
+if (png_ptr->push_length + 4 > png_ptr->buffer_size) \
+   { png_push_save_buffer(png_ptr); return; }
+#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \
+if (png_ptr->buffer_size < N) \
+   { png_push_save_buffer(png_ptr); return; }
+
+void PNGAPI
+png_process_data(png_structrp png_ptr, png_inforp info_ptr,
+    png_bytep buffer, png_size_t buffer_size)
+{
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   png_push_restore_buffer(png_ptr, buffer, buffer_size);
+
+   while (png_ptr->buffer_size)
+   {
+      png_process_some_data(png_ptr, info_ptr);
+   }
+}
+
+png_size_t PNGAPI
+png_process_data_pause(png_structrp png_ptr, int save)
+{
+   if (png_ptr != NULL)
+   {
+      /* It's easiest for the caller if we do the save; then the caller doesn't
+       * have to supply the same data again:
+       */
+      if (save != 0)
+         png_push_save_buffer(png_ptr);
+      else
+      {
+         /* This includes any pending saved bytes: */
+         png_size_t remaining = png_ptr->buffer_size;
+         png_ptr->buffer_size = 0;
+
+         /* So subtract the saved buffer size, unless all the data
+          * is actually 'saved', in which case we just return 0
+          */
+         if (png_ptr->save_buffer_size < remaining)
+            return remaining - png_ptr->save_buffer_size;
+      }
+   }
+
+   return 0;
+}
+
+png_uint_32 PNGAPI
+png_process_data_skip(png_structrp png_ptr)
+{
+/* TODO: Deprecate and remove this API.
+ * Somewhere the implementation of this seems to have been lost,
+ * or abandoned.  It was only to support some internal back-door access
+ * to png_struct) in libpng-1.4.x.
+ */
+   png_app_warning(png_ptr,
+"png_process_data_skip is not implemented in any current version of libpng");
+   return 0;
+}
+
+/* What we do with the incoming data depends on what we were previously
+ * doing before we ran out of data...
+ */
+void /* PRIVATE */
+png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
+{
+   if (png_ptr == NULL)
+      return;
+
+   switch (png_ptr->process_mode)
+   {
+      case PNG_READ_SIG_MODE:
+      {
+         png_push_read_sig(png_ptr, info_ptr);
+         break;
+      }
+
+      case PNG_READ_CHUNK_MODE:
+      {
+         png_push_read_chunk(png_ptr, info_ptr);
+         break;
+      }
+
+      case PNG_READ_IDAT_MODE:
+      {
+         png_push_read_IDAT(png_ptr);
+         break;
+      }
+
+      default:
+      {
+         png_ptr->buffer_size = 0;
+         break;
+      }
+   }
+}
+
+/* Read any remaining signature bytes from the stream and compare them with
+ * the correct PNG signature.  It is possible that this routine is called
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
+ */
+void /* PRIVATE */
+png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
+{
+   png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */
+       num_to_check = 8 - num_checked;
+
+   if (png_ptr->buffer_size < num_to_check)
+   {
+      num_to_check = png_ptr->buffer_size;
+   }
+
+   png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+       num_to_check);
+   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
+
+   if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
+   {
+      if (num_checked < 4 &&
+          png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+         png_error(png_ptr, "Not a PNG file");
+
+      else
+         png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+   }
+   else
+   {
+      if (png_ptr->sig_bytes >= 8)
+      {
+         png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+      }
+   }
+}
+
+void /* PRIVATE */
+png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
+{
+   png_uint_32 chunk_name;
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep; /* unknown handling method */
+#endif
+
+   /* First we make sure we have enough data for the 4-byte chunk name
+    * and the 4-byte chunk length before proceeding with decoding the
+    * chunk data.  To fully decode each of these chunks, we also make
+    * sure we have enough data in the buffer for the 4-byte CRC at the
+    * end of every chunk (except IDAT, which is handled separately).
+    */
+   if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
+   {
+      png_byte chunk_length[4];
+      png_byte chunk_tag[4];
+
+      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
+      png_push_fill_buffer(png_ptr, chunk_length, 4);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+      png_reset_crc(png_ptr);
+      png_crc_read(png_ptr, chunk_tag, 4);
+      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+      png_check_chunk_length(png_ptr, png_ptr->push_length);
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+   }
+
+   chunk_name = png_ptr->chunk_name;
+
+   if (chunk_name == png_IDAT)
+   {
+      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+      /* If we reach an IDAT chunk, this means we have read all of the
+       * header chunks, and we can start reading the image (or if this
+       * is called after the image has been read - we have an error).
+       */
+      if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+         png_error(png_ptr, "Missing IHDR before IDAT");
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+          (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+         png_error(png_ptr, "Missing PLTE before IDAT");
+
+      png_ptr->process_mode = PNG_READ_IDAT_MODE;
+
+      if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+         if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
+            if (png_ptr->push_length == 0)
+               return;
+
+      png_ptr->mode |= PNG_HAVE_IDAT;
+
+      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+         png_benign_error(png_ptr, "Too many IDATs found");
+   }
+
+   if (chunk_name == png_IHDR)
+   {
+      if (png_ptr->push_length != 13)
+         png_error(png_ptr, "Invalid IHDR length");
+
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+   else if (chunk_name == png_IEND)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
+
+      png_ptr->process_mode = PNG_READ_DONE_MODE;
+      png_push_have_end(png_ptr, info_ptr);
+   }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
+
+      if (chunk_name == png_PLTE)
+         png_ptr->mode |= PNG_HAVE_PLTE;
+   }
+#endif
+
+   else if (chunk_name == png_PLTE)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+   else if (chunk_name == png_IDAT)
+   {
+      png_ptr->idat_size = png_ptr->push_length;
+      png_ptr->process_mode = PNG_READ_IDAT_MODE;
+      png_push_have_info(png_ptr, info_ptr);
+      png_ptr->zstream.avail_out =
+          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
+          png_ptr->iwidth) + 1;
+      png_ptr->zstream.next_out = png_ptr->row_buf;
+      return;
+   }
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+   else if (png_ptr->chunk_name == png_gAMA)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_sBIT_SUPPORTED
+   else if (png_ptr->chunk_name == png_sBIT)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_cHRM_SUPPORTED
+   else if (png_ptr->chunk_name == png_cHRM)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_sRGB_SUPPORTED
+   else if (chunk_name == png_sRGB)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_iCCP_SUPPORTED
+   else if (png_ptr->chunk_name == png_iCCP)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_sPLT_SUPPORTED
+   else if (chunk_name == png_sPLT)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_tRNS_SUPPORTED
+   else if (chunk_name == png_tRNS)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_bKGD_SUPPORTED
+   else if (chunk_name == png_bKGD)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_hIST_SUPPORTED
+   else if (chunk_name == png_hIST)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_pHYs_SUPPORTED
+   else if (chunk_name == png_pHYs)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_oFFs_SUPPORTED
+   else if (chunk_name == png_oFFs)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+   else if (chunk_name == png_pCAL)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_sCAL_SUPPORTED
+   else if (chunk_name == png_sCAL)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_tIME_SUPPORTED
+   else if (chunk_name == png_tIME)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_tEXt_SUPPORTED
+   else if (chunk_name == png_tEXt)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_zTXt_SUPPORTED
+   else if (chunk_name == png_zTXt)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_iTXt_SUPPORTED
+   else if (chunk_name == png_iTXt)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+
+   else
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
+          PNG_HANDLE_CHUNK_AS_DEFAULT);
+   }
+
+   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+}
+
+void PNGCBAPI
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
+{
+   png_bytep ptr;
+
+   if (png_ptr == NULL)
+      return;
+
+   ptr = buffer;
+   if (png_ptr->save_buffer_size != 0)
+   {
+      png_size_t save_size;
+
+      if (length < png_ptr->save_buffer_size)
+         save_size = length;
+
+      else
+         save_size = png_ptr->save_buffer_size;
+
+      memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+      length -= save_size;
+      ptr += save_size;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->save_buffer_size -= save_size;
+      png_ptr->save_buffer_ptr += save_size;
+   }
+   if (length != 0 && png_ptr->current_buffer_size != 0)
+   {
+      png_size_t save_size;
+
+      if (length < png_ptr->current_buffer_size)
+         save_size = length;
+
+      else
+         save_size = png_ptr->current_buffer_size;
+
+      memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+      png_ptr->buffer_size -= save_size;
+      png_ptr->current_buffer_size -= save_size;
+      png_ptr->current_buffer_ptr += save_size;
+   }
+}
+
+void /* PRIVATE */
+png_push_save_buffer(png_structrp png_ptr)
+{
+   if (png_ptr->save_buffer_size != 0)
+   {
+      if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
+      {
+         png_size_t i, istop;
+         png_bytep sp;
+         png_bytep dp;
+
+         istop = png_ptr->save_buffer_size;
+         for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
+             i < istop; i++, sp++, dp++)
+         {
+            *dp = *sp;
+         }
+      }
+   }
+   if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
+       png_ptr->save_buffer_max)
+   {
+      png_size_t new_max;
+      png_bytep old_buffer;
+
+      if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+          (png_ptr->current_buffer_size + 256))
+      {
+         png_error(png_ptr, "Potential overflow of save_buffer");
+      }
+
+      new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
+      old_buffer = png_ptr->save_buffer;
+      png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+          (png_size_t)new_max);
+
+      if (png_ptr->save_buffer == NULL)
+      {
+         png_free(png_ptr, old_buffer);
+         png_error(png_ptr, "Insufficient memory for save_buffer");
+      }
+
+      if (old_buffer)
+         memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+      else if (png_ptr->save_buffer_size)
+         png_error(png_ptr, "save_buffer error");
+      png_free(png_ptr, old_buffer);
+      png_ptr->save_buffer_max = new_max;
+   }
+   if (png_ptr->current_buffer_size)
+   {
+      memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+         png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
+      png_ptr->save_buffer_size += png_ptr->current_buffer_size;
+      png_ptr->current_buffer_size = 0;
+   }
+   png_ptr->save_buffer_ptr = png_ptr->save_buffer;
+   png_ptr->buffer_size = 0;
+}
+
+void /* PRIVATE */
+png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
+    png_size_t buffer_length)
+{
+   png_ptr->current_buffer = buffer;
+   png_ptr->current_buffer_size = buffer_length;
+   png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
+   png_ptr->current_buffer_ptr = png_ptr->current_buffer;
+}
+
+void /* PRIVATE */
+png_push_read_IDAT(png_structrp png_ptr)
+{
+   if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
+   {
+      png_byte chunk_length[4];
+      png_byte chunk_tag[4];
+
+      /* TODO: this code can be commoned up with the same code in push_read */
+      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
+      png_push_fill_buffer(png_ptr, chunk_length, 4);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
+      png_reset_crc(png_ptr);
+      png_crc_read(png_ptr, chunk_tag, 4);
+      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+
+      if (png_ptr->chunk_name != png_IDAT)
+      {
+         png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+
+         if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+            png_error(png_ptr, "Not enough compressed data");
+
+         return;
+      }
+
+      png_ptr->idat_size = png_ptr->push_length;
+   }
+
+   if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
+   {
+      png_size_t save_size = png_ptr->save_buffer_size;
+      png_uint_32 idat_size = png_ptr->idat_size;
+
+      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+       * are of different types and we don't know which variable has the fewest
+       * bits.  Carefully select the smaller and cast it to the type of the
+       * larger - this cannot overflow.  Do not cast in the following test - it
+       * will break on either 16-bit or 64-bit platforms.
+       */
+      if (idat_size < save_size)
+         save_size = (png_size_t)idat_size;
+
+      else
+         idat_size = (png_uint_32)save_size;
+
+      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+      png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
+
+      png_ptr->idat_size -= idat_size;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->save_buffer_size -= save_size;
+      png_ptr->save_buffer_ptr += save_size;
+   }
+
+   if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0)
+   {
+      png_size_t save_size = png_ptr->current_buffer_size;
+      png_uint_32 idat_size = png_ptr->idat_size;
+
+      /* We want the smaller of 'idat_size' and 'current_buffer_size', but they
+       * are of different types and we don't know which variable has the fewest
+       * bits.  Carefully select the smaller and cast it to the type of the
+       * larger - this cannot overflow.
+       */
+      if (idat_size < save_size)
+         save_size = (png_size_t)idat_size;
+
+      else
+         idat_size = (png_uint_32)save_size;
+
+      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+      png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
+
+      png_ptr->idat_size -= idat_size;
+      png_ptr->buffer_size -= save_size;
+      png_ptr->current_buffer_size -= save_size;
+      png_ptr->current_buffer_ptr += save_size;
+   }
+
+   if (png_ptr->idat_size == 0)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_LT(4)
+      png_crc_finish(png_ptr, 0);
+      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+      png_ptr->mode |= PNG_AFTER_IDAT;
+      png_ptr->zowner = 0;
+   }
+}
+
+void /* PRIVATE */
+png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
+    png_size_t buffer_length)
+{
+   /* The caller checks for a non-zero buffer length. */
+   if (!(buffer_length > 0) || buffer == NULL)
+      png_error(png_ptr, "No IDAT data (internal error)");
+
+   /* This routine must process all the data it has been given
+    * before returning, calling the row callback as required to
+    * handle the uncompressed results.
+    */
+   png_ptr->zstream.next_in = buffer;
+   /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+   png_ptr->zstream.avail_in = (uInt)buffer_length;
+
+   /* Keep going until the decompressed data is all processed
+    * or the stream marked as finished.
+    */
+   while (png_ptr->zstream.avail_in > 0 &&
+      (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+   {
+      int ret;
+
+      /* We have data for zlib, but we must check that zlib
+       * has someplace to put the results.  It doesn't matter
+       * if we don't expect any results -- it may be the input
+       * data is just the LZ end code.
+       */
+      if (!(png_ptr->zstream.avail_out > 0))
+      {
+         /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+         png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+             png_ptr->iwidth) + 1);
+
+         png_ptr->zstream.next_out = png_ptr->row_buf;
+      }
+
+      /* Using Z_SYNC_FLUSH here means that an unterminated
+       * LZ stream (a stream with a missing end code) can still
+       * be handled, otherwise (Z_NO_FLUSH) a future zlib
+       * implementation might defer output and therefore
+       * change the current behavior (see comments in inflate.c
+       * for why this doesn't happen at present with zlib 1.2.5).
+       */
+      ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH);
+
+      /* Check for any failure before proceeding. */
+      if (ret != Z_OK && ret != Z_STREAM_END)
+      {
+         /* Terminate the decompression. */
+         png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+         png_ptr->zowner = 0;
+
+         /* This may be a truncated stream (missing or
+          * damaged end code).  Treat that as a warning.
+          */
+         if (png_ptr->row_number >= png_ptr->num_rows ||
+             png_ptr->pass > 6)
+            png_warning(png_ptr, "Truncated compressed data in IDAT");
+
+         else
+         {
+            if (ret == Z_DATA_ERROR)
+               png_benign_error(png_ptr, "IDAT: ADLER32 checksum mismatch");
+            else
+               png_error(png_ptr, "Decompression error in IDAT");
+         }
+
+         /* Skip the check on unprocessed input */
+         return;
+      }
+
+      /* Did inflate output any data? */
+      if (png_ptr->zstream.next_out != png_ptr->row_buf)
+      {
+         /* Is this unexpected data after the last row?
+          * If it is, artificially terminate the LZ output
+          * here.
+          */
+         if (png_ptr->row_number >= png_ptr->num_rows ||
+             png_ptr->pass > 6)
+         {
+            /* Extra data. */
+            png_warning(png_ptr, "Extra compressed data in IDAT");
+            png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+            png_ptr->zowner = 0;
+
+            /* Do no more processing; skip the unprocessed
+             * input check below.
+             */
+            return;
+         }
+
+         /* Do we have a complete row? */
+         if (png_ptr->zstream.avail_out == 0)
+            png_push_process_row(png_ptr);
+      }
+
+      /* And check for the end of the stream. */
+      if (ret == Z_STREAM_END)
+         png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+   }
+
+   /* All the data should have been processed, if anything
+    * is left at this point we have bytes of IDAT data
+    * after the zlib end code.
+    */
+   if (png_ptr->zstream.avail_in > 0)
+      png_warning(png_ptr, "Extra compression data in IDAT");
+}
+
+void /* PRIVATE */
+png_push_process_row(png_structrp png_ptr)
+{
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   png_row_info row_info;
+
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
+
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * it may not be in the future, so this was changed just to copy the
+    * interlaced row count:
+    */
+   memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   if (png_ptr->transformations != 0)
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "progressive row overflow");
+   }
+
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal progressive row size calculation error");
+
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Expand interlaced rows to full size */
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
+   {
+      if (png_ptr->pass < 6)
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+             png_ptr->transformations);
+
+      switch (png_ptr->pass)
+      {
+         case 0:
+         {
+            int i;
+            for (i = 0; i < 8 && png_ptr->pass == 0; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
+            }
+
+            if (png_ptr->pass == 2) /* Pass 1 might be empty */
+            {
+               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+
+            if (png_ptr->pass == 4 && png_ptr->height <= 4)
+            {
+               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+
+            if (png_ptr->pass == 6 && png_ptr->height <= 4)
+            {
+                png_push_have_row(png_ptr, NULL);
+                png_read_push_finish_row(png_ptr);
+            }
+
+            break;
+         }
+
+         case 1:
+         {
+            int i;
+            for (i = 0; i < 8 && png_ptr->pass == 1; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            if (png_ptr->pass == 2) /* Skip top 4 generated rows */
+            {
+               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+
+            break;
+         }
+
+         case 2:
+         {
+            int i;
+
+            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            if (png_ptr->pass == 4) /* Pass 3 might be empty */
+            {
+               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+
+            break;
+         }
+
+         case 3:
+         {
+            int i;
+
+            for (i = 0; i < 4 && png_ptr->pass == 3; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            if (png_ptr->pass == 4) /* Skip top two generated rows */
+            {
+               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+               {
+                  png_push_have_row(png_ptr, NULL);
+                  png_read_push_finish_row(png_ptr);
+               }
+            }
+
+            break;
+         }
+
+         case 4:
+         {
+            int i;
+
+            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            if (png_ptr->pass == 6) /* Pass 5 might be empty */
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            break;
+         }
+
+         case 5:
+         {
+            int i;
+
+            for (i = 0; i < 2 && png_ptr->pass == 5; i++)
+            {
+               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            if (png_ptr->pass == 6) /* Skip top generated row */
+            {
+               png_push_have_row(png_ptr, NULL);
+               png_read_push_finish_row(png_ptr);
+            }
+
+            break;
+         }
+
+         default:
+         case 6:
+         {
+            png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+            png_read_push_finish_row(png_ptr);
+
+            if (png_ptr->pass != 6)
+               break;
+
+            png_push_have_row(png_ptr, NULL);
+            png_read_push_finish_row(png_ptr);
+         }
+      }
+   }
+   else
+#endif
+   {
+      png_push_have_row(png_ptr, png_ptr->row_buf + 1);
+      png_read_push_finish_row(png_ptr);
+   }
+}
+
+void /* PRIVATE */
+png_read_push_finish_row(png_structrp png_ptr)
+{
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+   /* Height of interlace block.  This is not currently used - if you need
+    * it, uncomment it here and in png.h
+   static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+   */
+#endif
+
+   png_ptr->row_number++;
+   if (png_ptr->row_number < png_ptr->num_rows)
+      return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced != 0)
+   {
+      png_ptr->row_number = 0;
+      memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+      do
+      {
+         png_ptr->pass++;
+         if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+             (png_ptr->pass == 3 && png_ptr->width < 3) ||
+             (png_ptr->pass == 5 && png_ptr->width < 2))
+            png_ptr->pass++;
+
+         if (png_ptr->pass > 7)
+            png_ptr->pass--;
+
+         if (png_ptr->pass >= 7)
+            break;
+
+         png_ptr->iwidth = (png_ptr->width +
+             png_pass_inc[png_ptr->pass] - 1 -
+             png_pass_start[png_ptr->pass]) /
+             png_pass_inc[png_ptr->pass];
+
+         if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+            break;
+
+         png_ptr->num_rows = (png_ptr->height +
+             png_pass_yinc[png_ptr->pass] - 1 -
+             png_pass_ystart[png_ptr->pass]) /
+             png_pass_yinc[png_ptr->pass];
+
+      } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
+   }
+#endif /* READ_INTERLACING */
+}
+
+void /* PRIVATE */
+png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+   if (png_ptr->info_fn != NULL)
+      (*(png_ptr->info_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+   if (png_ptr->end_fn != NULL)
+      (*(png_ptr->end_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_row(png_structrp png_ptr, png_bytep row)
+{
+   if (png_ptr->row_fn != NULL)
+      (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
+          (int)png_ptr->pass);
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void PNGAPI
+png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
+    png_const_bytep new_row)
+{
+   if (png_ptr == NULL)
+      return;
+
+   /* new_row is a flag here - if it is NULL then the app callback was called
+    * from an empty row (see the calls to png_struct::row_fn below), otherwise
+    * it must be png_ptr->row_buf+1
+    */
+   if (new_row != NULL)
+      png_combine_row(png_ptr, old_row, 1/*blocky display*/);
+}
+#endif /* READ_INTERLACING */
+
+void PNGAPI
+png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
+    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
+    png_progressive_end_ptr end_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->info_fn = info_fn;
+   png_ptr->row_fn = row_fn;
+   png_ptr->end_fn = end_fn;
+
+   png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
+}
+
+png_voidp PNGAPI
+png_get_progressive_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+
+   return png_ptr->io_ptr;
+}
+#endif /* PROGRESSIVE_READ */
diff --git a/xs/src/png/libpng/pngpriv.h b/xs/src/png/libpng/pngpriv.h
new file mode 100644
index 000000000..1f2e90f2b
--- /dev/null
+++ b/xs/src/png/libpng/pngpriv.h
@@ -0,0 +1,2120 @@
+
+/* pngpriv.h - private declarations for use inside libpng
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The symbols declared in this file (including the functions declared
+ * as extern) are PRIVATE.  They are not part of the libpng public
+ * interface, and are not recommended for use by regular applications.
+ * Some of them may become public in the future; others may stay private,
+ * change in an incompatible way, or even disappear.
+ * Although the libpng users are not forbidden to include this header,
+ * they should be well aware of the issues that may arise from doing so.
+ */
+
+#ifndef PNGPRIV_H
+#define PNGPRIV_H
+
+/* Feature Test Macros.  The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#ifndef _POSIX_SOURCE
+# define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Standard library headers not required by png.h: */
+#  include <stdlib.h>
+#  include <string.h>
+#endif
+
+#define PNGLIB_BUILD /*libpng is being built, not used*/
+
+/* If HAVE_CONFIG_H is defined during the build then the build system must
+ * provide an appropriate "config.h" file on the include path.  The header file
+ * must provide definitions as required below (search for "HAVE_CONFIG_H");
+ * see configure.ac for more details of the requirements.  The macro
+ * "PNG_NO_CONFIG_H" is provided for maintainers to test for dependencies on
+ * 'configure'; define this macro to prevent the configure build including the
+ * configure generated config.h.  Libpng is expected to compile without *any*
+ * special build system support on a reasonably ANSI-C compliant system.
+ */
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+#  include <config.h>
+
+   /* Pick up the definition of 'restrict' from config.h if it was read: */
+#  define PNG_RESTRICT restrict
+#endif
+
+/* To support symbol prefixing it is necessary to know *before* including png.h
+ * whether the fixed point (and maybe other) APIs are exported, because if they
+ * are not internal definitions may be required.  This is handled below just
+ * before png.h is included, but load the configuration now if it is available.
+ */
+#ifndef PNGLCONF_H
+#  include "pnglibconf.h"
+#endif
+
+/* Local renames may change non-exported API functions from png.h */
+#if defined(PNG_PREFIX) && !defined(PNGPREFIX_H)
+#  include "pngprefix.h"
+#endif
+
+#ifdef PNG_USER_CONFIG
+#  include "pngusr.h"
+   /* These should have been defined in pngusr.h */
+#  ifndef PNG_USER_PRIVATEBUILD
+#    define PNG_USER_PRIVATEBUILD "Custom libpng build"
+#  endif
+#  ifndef PNG_USER_DLLFNAME_POSTFIX
+#    define PNG_USER_DLLFNAME_POSTFIX "Cb"
+#  endif
+#endif
+
+/* Compile time options.
+ * =====================
+ * In a multi-arch build the compiler may compile the code several times for the
+ * same object module, producing different binaries for different architectures.
+ * When this happens configure-time setting of the target host options cannot be
+ * done and this interferes with the handling of the ARM NEON optimizations, and
+ * possibly other similar optimizations.  Put additional tests here; in general
+ * this is needed when the same option can be changed at both compile time and
+ * run time depending on the target OS (i.e. iOS vs Android.)
+ *
+ * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
+ * this is not possible with certain compilers (Oracle SUN OS CC), as a result
+ * it is necessary to ensure that all extern functions that *might* be used
+ * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
+ * below is one example of this behavior because it is controlled by the
+ * presence or not of -mfpu=neon on the GCC command line, it is possible to do
+ * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
+ * do this.
+ */
+#ifndef PNG_ARM_NEON_OPT
+   /* ARM NEON optimizations are being controlled by the compiler settings,
+    * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
+    * with GCC) then the compiler will define __ARM_NEON__ and we can rely
+    * unconditionally on NEON instructions not crashing, otherwise we must
+    * disable use of NEON instructions.
+    *
+    * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
+    * can only be turned on automatically if that is supported too.  If
+    * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
+    * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
+    * off.
+    *
+    * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
+    * __ARM_NEON__, so we check both variants.
+    *
+    * To disable ARM_NEON optimizations entirely, and skip compiling the
+    * associated assembler code, pass --enable-arm-neon=no to configure
+    * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
+    */
+#  if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
+   defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+#     define PNG_ARM_NEON_OPT 2
+#  else
+#     define PNG_ARM_NEON_OPT 0
+#  endif
+#endif
+
+#if PNG_ARM_NEON_OPT > 0
+   /* NEON optimizations are to be at least considered by libpng, so enable the
+    * callbacks to do this.
+    */
+#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
+
+   /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
+    * if possible - if __ARM_NEON__ is set and the compiler version is not known
+    * to be broken.  This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
+    * be:
+    *
+    *    1  The intrinsics code (the default with __ARM_NEON__)
+    *    2  The hand coded assembler (the default without __ARM_NEON__)
+    *
+    * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
+    * this is *NOT* supported and may cease to work even after a minor revision
+    * to libpng.  It *is* valid to do this for testing purposes, e.g. speed
+    * testing or a new compiler, but the results should be communicated to the
+    * libpng implementation list for incorporation in the next minor release.
+    */
+#  ifndef PNG_ARM_NEON_IMPLEMENTATION
+#     if defined(__ARM_NEON__) || defined(__ARM_NEON)
+#        if defined(__clang__)
+            /* At present it is unknown by the libpng developers which versions
+             * of clang support the intrinsics, however some or perhaps all
+             * versions do not work with the assembler so this may be
+             * irrelevant, so just use the default (do nothing here.)
+             */
+#        elif defined(__GNUC__)
+            /* GCC 4.5.4 NEON support is known to be broken.  4.6.3 is known to
+             * work, so if this *is* GCC, or G++, look for a version >4.5
+             */
+#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
+#              define PNG_ARM_NEON_IMPLEMENTATION 2
+#           endif /* no GNUC support */
+#        endif /* __GNUC__ */
+#     else /* !defined __ARM_NEON__ */
+         /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
+          */
+#        define PNG_ARM_NEON_IMPLEMENTATION 2
+#     endif /* __ARM_NEON__ */
+#  endif /* !PNG_ARM_NEON_IMPLEMENTATION */
+
+#  ifndef PNG_ARM_NEON_IMPLEMENTATION
+      /* Use the intrinsics code by default. */
+#     define PNG_ARM_NEON_IMPLEMENTATION 1
+#  endif
+#endif /* PNG_ARM_NEON_OPT > 0 */
+
+#ifndef PNG_MIPS_MSA_OPT
+#  if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+#     define PNG_MIPS_MSA_OPT 2
+#  else
+#     define PNG_MIPS_MSA_OPT 0
+#  endif
+#endif
+
+#ifndef PNG_POWERPC_VSX_OPT
+#  if defined(__PPC64__) && defined(__ALTIVEC__) && defined(__VSX__)
+#     define PNG_POWERPC_VSX_OPT 2
+#  else
+#     define PNG_POWERPC_VSX_OPT 0
+#  endif
+#endif
+
+#ifndef PNG_INTEL_SSE_OPT
+#   ifdef PNG_INTEL_SSE
+      /* Only check for SSE if the build configuration has been modified to
+       * enable SSE optimizations.  This means that these optimizations will
+       * be off by default.  See contrib/intel for more details.
+       */
+#     if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
+       defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
+       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
+#         define PNG_INTEL_SSE_OPT 1
+#      endif
+#   endif
+#endif
+
+#if PNG_INTEL_SSE_OPT > 0
+#   ifndef PNG_INTEL_SSE_IMPLEMENTATION
+#      if defined(__SSE4_1__) || defined(__AVX__)
+          /* We are not actually using AVX, but checking for AVX is the best
+             way we can detect SSE4.1 and SSSE3 on MSVC.
+          */
+#         define PNG_INTEL_SSE_IMPLEMENTATION 3
+#      elif defined(__SSSE3__)
+#         define PNG_INTEL_SSE_IMPLEMENTATION 2
+#      elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
+       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
+#         define PNG_INTEL_SSE_IMPLEMENTATION 1
+#      else
+#         define PNG_INTEL_SSE_IMPLEMENTATION 0
+#      endif
+#   endif
+
+#   if PNG_INTEL_SSE_IMPLEMENTATION > 0
+#      define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2
+#   endif
+#endif
+
+#if PNG_MIPS_MSA_OPT > 0
+#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_msa
+#  ifndef PNG_MIPS_MSA_IMPLEMENTATION
+#     if defined(__mips_msa)
+#        if defined(__clang__)
+#        elif defined(__GNUC__)
+#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
+#              define PNG_MIPS_MSA_IMPLEMENTATION 2
+#           endif /* no GNUC support */
+#        endif /* __GNUC__ */
+#     else /* !defined __mips_msa */
+#        define PNG_MIPS_MSA_IMPLEMENTATION 2
+#     endif /* __mips_msa */
+#  endif /* !PNG_MIPS_MSA_IMPLEMENTATION */
+
+#  ifndef PNG_MIPS_MSA_IMPLEMENTATION
+#     define PNG_MIPS_MSA_IMPLEMENTATION 1
+#  endif
+#endif /* PNG_MIPS_MSA_OPT > 0 */
+
+#if PNG_POWERPC_VSX_OPT > 0
+#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
+#  define PNG_POWERPC_VSX_IMPLEMENTATION 1
+#endif
+
+
+/* Is this a build of a DLL where compilation of the object modules requires
+ * different preprocessor settings to those required for a simple library?  If
+ * so PNG_BUILD_DLL must be set.
+ *
+ * If libpng is used inside a DLL but that DLL does not export the libpng APIs
+ * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
+ * static library of libpng then link the DLL against that.
+ */
+#ifndef PNG_BUILD_DLL
+#  ifdef DLL_EXPORT
+      /* This is set by libtool when files are compiled for a DLL; libtool
+       * always compiles twice, even on systems where it isn't necessary.  Set
+       * PNG_BUILD_DLL in case it is necessary:
+       */
+#     define PNG_BUILD_DLL
+#  else
+#     ifdef _WINDLL
+         /* This is set by the Microsoft Visual Studio IDE in projects that
+          * build a DLL.  It can't easily be removed from those projects (it
+          * isn't visible in the Visual Studio UI) so it is a fairly reliable
+          * indication that PNG_IMPEXP needs to be set to the DLL export
+          * attributes.
+          */
+#        define PNG_BUILD_DLL
+#     else
+#        ifdef __DLL__
+            /* This is set by the Borland C system when compiling for a DLL
+             * (as above.)
+             */
+#           define PNG_BUILD_DLL
+#        else
+            /* Add additional compiler cases here. */
+#        endif
+#     endif
+#  endif
+#endif /* Setting PNG_BUILD_DLL if required */
+
+/* See pngconf.h for more details: the builder of the library may set this on
+ * the command line to the right thing for the specific compilation system or it
+ * may be automagically set above (at present we know of no system where it does
+ * need to be set on the command line.)
+ *
+ * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
+ * setting it to the "import" setting for a DLL build.
+ */
+#ifndef PNG_IMPEXP
+#  ifdef PNG_BUILD_DLL
+#     define PNG_IMPEXP PNG_DLL_EXPORT
+#  else
+      /* Not building a DLL, or the DLL doesn't require specific export
+       * definitions.
+       */
+#     define PNG_IMPEXP
+#  endif
+#endif
+
+/* No warnings for private or deprecated functions in the build: */
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE
+#endif
+
+/* Symbol preprocessing support.
+ *
+ * To enable listing global, but internal, symbols the following macros should
+ * always be used to declare an extern data or function object in this file.
+ */
+#ifndef PNG_INTERNAL_DATA
+#  define PNG_INTERNAL_DATA(type, name, array) PNG_LINKAGE_DATA type name array
+#endif
+
+#ifndef PNG_INTERNAL_FUNCTION
+#  define PNG_INTERNAL_FUNCTION(type, name, args, attributes)\
+      PNG_LINKAGE_FUNCTION PNG_FUNCTION(type, name, args, PNG_EMPTY attributes)
+#endif
+
+#ifndef PNG_INTERNAL_CALLBACK
+#  define PNG_INTERNAL_CALLBACK(type, name, args, attributes)\
+      PNG_LINKAGE_CALLBACK PNG_FUNCTION(type, (PNGCBAPI name), args,\
+         PNG_EMPTY attributes)
+#endif
+
+/* If floating or fixed point APIs are disabled they may still be compiled
+ * internally.  To handle this make sure they are declared as the appropriate
+ * internal extern function (otherwise the symbol prefixing stuff won't work and
+ * the functions will be used without definitions.)
+ *
+ * NOTE: although all the API functions are declared here they are not all
+ * actually built!  Because the declarations are still made it is necessary to
+ * fake out types that they depend on.
+ */
+#ifndef PNG_FP_EXPORT
+#  ifndef PNG_FLOATING_POINT_SUPPORTED
+#     define PNG_FP_EXPORT(ordinal, type, name, args)\
+         PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+#     ifndef PNG_VERSION_INFO_ONLY
+         typedef struct png_incomplete png_double;
+         typedef png_double*           png_doublep;
+         typedef const png_double*     png_const_doublep;
+         typedef png_double**          png_doublepp;
+#     endif
+#  endif
+#endif
+#ifndef PNG_FIXED_EXPORT
+#  ifndef PNG_FIXED_POINT_SUPPORTED
+#     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
+         PNG_INTERNAL_FUNCTION(type, name, args, PNG_EMPTY);
+#  endif
+#endif
+
+#include "png.h"
+
+/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
+#ifndef PNG_DLL_EXPORT
+#  define PNG_DLL_EXPORT
+#endif
+
+/* This is a global switch to set the compilation for an installed system
+ * (a release build).  It can be set for testing debug builds to ensure that
+ * they will compile when the build type is switched to RC or STABLE, the
+ * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE.  Set this in CPPFLAGS
+ * with either:
+ *
+ *   -DPNG_RELEASE_BUILD Turns on the release compile path
+ *   -DPNG_RELEASE_BUILD=0 Turns it off
+ * or in your pngusr.h with
+ *   #define PNG_RELEASE_BUILD=1 Turns on the release compile path
+ *   #define PNG_RELEASE_BUILD=0 Turns it off
+ */
+#ifndef PNG_RELEASE_BUILD
+#  define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
+#endif
+
+/* SECURITY and SAFETY:
+ *
+ * libpng is built with support for internal limits on image dimensions and
+ * memory usage.  These are documented in scripts/pnglibconf.dfa of the
+ * source and recorded in the machine generated header file pnglibconf.h.
+ */
+
+/* If you are running on a machine where you cannot allocate more
+ * than 64K of memory at once, uncomment this.  While libpng will not
+ * normally need that much memory in a chunk (unless you load up a very
+ * large file), zlib needs to know how big of a chunk it can use, and
+ * libpng thus makes sure to check any memory allocation to verify it
+ * will fit into memory.
+ *
+ * zlib provides 'MAXSEG_64K' which, if defined, indicates the
+ * same limit and pngconf.h (already included) sets the limit
+ * if certain operating systems are detected.
+ */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+#  define PNG_MAX_MALLOC_64K
+#endif
+
+#ifndef PNG_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).  Note that if you replace
+ * it with something other than whitespace, you must include the terminating
+ * semicolon.
+ */
+#  define PNG_UNUSED(param) (void)param;
+#endif
+
+/* Just a little check that someone hasn't tried to define something
+ * contradictory.
+ */
+#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K)
+#  undef PNG_ZBUF_SIZE
+#  define PNG_ZBUF_SIZE 65536L
+#endif
+
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+#  define png_warning_parameter(p,number,string) ((void)0)
+#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
+#  define png_formatted_warning(pp,p,message) ((void)(pp))
+#  define PNG_WARNING_PARAMETERS(p)
+#endif
+#ifndef PNG_ERROR_TEXT_SUPPORTED
+#  define png_fixed_error(s1,s2) png_err(s1)
+#endif
+
+/* Some fixed point APIs are still required even if not exported because
+ * they get used by the corresponding floating point APIs.  This magic
+ * deals with this:
+ */
+#ifdef PNG_FIXED_POINT_SUPPORTED
+#  define PNGFAPI PNGAPI
+#else
+#  define PNGFAPI /* PRIVATE */
+#endif
+
+#ifndef PNG_VERSION_INFO_ONLY
+/* Other defines specific to compilers can go here.  Try to keep
+ * them inside an appropriate ifdef/endif pair for portability.
+ */
+
+/* C allows up-casts from (void*) to any pointer and (const void*) to any
+ * pointer to a const object.  C++ regards this as a type error and requires an
+ * explicit, static, cast and provides the static_cast<> rune to ensure that
+ * const is not cast away.
+ */
+#ifdef __cplusplus
+#  define png_voidcast(type, value) static_cast<type>(value)
+#  define png_constcast(type, value) const_cast<type>(value)
+#  define png_aligncast(type, value) \
+   static_cast<type>(static_cast<void*>(value))
+#  define png_aligncastconst(type, value) \
+   static_cast<type>(static_cast<const void*>(value))
+#else
+#  define png_voidcast(type, value) (value)
+#  ifdef _WIN64
+#     ifdef __GNUC__
+         typedef unsigned long long png_ptruint;
+#     else
+         typedef unsigned __int64 png_ptruint;
+#     endif
+#  else
+      typedef unsigned long png_ptruint;
+#  endif
+#  define png_constcast(type, value) ((type)(png_ptruint)(const void*)(value))
+#  define png_aligncast(type, value) ((void*)(value))
+#  define png_aligncastconst(type, value) ((const void*)(value))
+#endif /* __cplusplus */
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\
+    defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
+   /* png.c requires the following ANSI-C constants if the conversion of
+    * floating point to ASCII is implemented therein:
+    *
+    *  DBL_DIG  Maximum number of decimal digits (can be set to any constant)
+    *  DBL_MIN  Smallest normalized fp number (can be set to an arbitrary value)
+    *  DBL_MAX  Maximum floating point number (can be set to an arbitrary value)
+    */
+#  include <float.h>
+
+#  if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \
+    defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC)
+   /* We need to check that <math.h> hasn't already been included earlier
+    * as it seems it doesn't agree with <fp.h>, yet we should really use
+    * <fp.h> if possible.
+    */
+#    if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__)
+#      include <fp.h>
+#    endif
+#  else
+#    include <math.h>
+#  endif
+#  if defined(_AMIGA) && defined(__SASC) && defined(_M68881)
+   /* Amiga SAS/C: We must include builtin FPU functions when compiling using
+    * MATH=68881
+    */
+#    include <m68881.h>
+#  endif
+#endif
+
+/* This provides the non-ANSI (far) memory allocation routines. */
+#if defined(__TURBOC__) && defined(__MSDOS__)
+#  include <mem.h>
+#  include <alloc.h>
+#endif
+
+#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
+    defined(_WIN32) || defined(__WIN32__)
+#  include <windows.h>  /* defines _WINDOWS_ macro */
+#endif
+#endif /* PNG_VERSION_INFO_ONLY */
+
+/* Moved here around 1.5.0beta36 from pngconf.h */
+/* Users may want to use these so they are not private.  Any library
+ * functions that are passed far data must be model-independent.
+ */
+
+/* Memory model/platform independent fns */
+#ifndef PNG_ABORT
+#  ifdef _WINDOWS_
+#    define PNG_ABORT() ExitProcess(0)
+#  else
+#    define PNG_ABORT() abort()
+#  endif
+#endif
+
+/* These macros may need to be architecture dependent. */
+#define PNG_ALIGN_NONE   0 /* do not use data alignment */
+#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
+#ifdef offsetof
+#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
+#else
+#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
+#endif
+#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
+
+#ifndef PNG_ALIGN_TYPE
+   /* Default to using aligned access optimizations and requiring alignment to a
+    * multiple of the data type size.  Override in a compiler specific fashion
+    * if necessary by inserting tests here:
+    */
+#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
+#endif
+
+#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
+   /* This is used because in some compiler implementations non-aligned
+    * structure members are supported, so the offsetof approach below fails.
+    * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
+    * is good for performance.  Do not do this unless you have tested the result
+    * and understand it.
+    */
+#  define png_alignof(type) (sizeof (type))
+#else
+#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
+#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
+#  else
+#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
+#        define png_alignof(type) (1)
+#     endif
+      /* Else leave png_alignof undefined to prevent use thereof */
+#  endif
+#endif
+
+/* This implicitly assumes alignment is always to a power of 2. */
+#ifdef png_alignof
+#  define png_isaligned(ptr, type)\
+   (((type)((const char*)ptr-(const char*)0) & \
+   (type)(png_alignof(type)-1)) == 0)
+#else
+#  define png_isaligned(ptr, type) 0
+#endif
+
+/* End of memory model/platform independent support */
+/* End of 1.5.0beta36 move from pngconf.h */
+
+/* CONSTANTS and UTILITY MACROS
+ * These are used internally by libpng and not exposed in the API
+ */
+
+/* Various modes of operation.  Note that after an init, mode is set to
+ * zero automatically when the structure is created.  Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
+ */
+/* #define PNG_HAVE_IHDR            0x01U (defined in png.h) */
+/* #define PNG_HAVE_PLTE            0x02U (defined in png.h) */
+#define PNG_HAVE_IDAT               0x04U
+/* #define PNG_AFTER_IDAT           0x08U (defined in png.h) */
+#define PNG_HAVE_IEND               0x10U
+                   /*               0x20U (unused) */
+                   /*               0x40U (unused) */
+                   /*               0x80U (unused) */
+#define PNG_HAVE_CHUNK_HEADER      0x100U
+#define PNG_WROTE_tIME             0x200U
+#define PNG_WROTE_INFO_BEFORE_PLTE 0x400U
+#define PNG_BACKGROUND_IS_GRAY     0x800U
+#define PNG_HAVE_PNG_SIGNATURE    0x1000U
+#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
+                   /*             0x4000U (unused) */
+#define PNG_IS_READ_STRUCT        0x8000U /* Else is a write struct */
+
+/* Flags for the transformations the PNG library does on the image data */
+#define PNG_BGR                 0x0001U
+#define PNG_INTERLACE           0x0002U
+#define PNG_PACK                0x0004U
+#define PNG_SHIFT               0x0008U
+#define PNG_SWAP_BYTES          0x0010U
+#define PNG_INVERT_MONO         0x0020U
+#define PNG_QUANTIZE            0x0040U
+#define PNG_COMPOSE             0x0080U    /* Was PNG_BACKGROUND */
+#define PNG_BACKGROUND_EXPAND   0x0100U
+#define PNG_EXPAND_16           0x0200U    /* Added to libpng 1.5.2 */
+#define PNG_16_TO_8             0x0400U    /* Becomes 'chop' in 1.5.4 */
+#define PNG_RGBA                0x0800U
+#define PNG_EXPAND              0x1000U
+#define PNG_GAMMA               0x2000U
+#define PNG_GRAY_TO_RGB         0x4000U
+#define PNG_FILLER              0x8000U
+#define PNG_PACKSWAP           0x10000U
+#define PNG_SWAP_ALPHA         0x20000U
+#define PNG_STRIP_ALPHA        0x40000U
+#define PNG_INVERT_ALPHA       0x80000U
+#define PNG_USER_TRANSFORM    0x100000U
+#define PNG_RGB_TO_GRAY_ERR   0x200000U
+#define PNG_RGB_TO_GRAY_WARN  0x400000U
+#define PNG_RGB_TO_GRAY       0x600000U /* two bits, RGB_TO_GRAY_ERR|WARN */
+#define PNG_ENCODE_ALPHA      0x800000U /* Added to libpng-1.5.4 */
+#define PNG_ADD_ALPHA        0x1000000U /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS      0x2000000U /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8    0x4000000U /* Added to libpng-1.5.4 */
+                       /*    0x8000000U unused */
+                       /*   0x10000000U unused */
+                       /*   0x20000000U unused */
+                       /*   0x40000000U unused */
+/* Flags for png_create_struct */
+#define PNG_STRUCT_PNG   0x0001U
+#define PNG_STRUCT_INFO  0x0002U
+
+/* Flags for the png_ptr->flags rather than declaring a byte for each one */
+#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001U
+#define PNG_FLAG_ZSTREAM_INITIALIZED      0x0002U /* Added to libpng-1.6.0 */
+                                  /*      0x0004U    unused */
+#define PNG_FLAG_ZSTREAM_ENDED            0x0008U /* Added to libpng-1.6.0 */
+                                  /*      0x0010U    unused */
+                                  /*      0x0020U    unused */
+#define PNG_FLAG_ROW_INIT                 0x0040U
+#define PNG_FLAG_FILLER_AFTER             0x0080U
+#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100U
+#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200U
+#define PNG_FLAG_CRC_CRITICAL_USE         0x0400U
+#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800U
+#define PNG_FLAG_ASSUME_sRGB              0x1000U /* Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000U /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000U /* Added to libpng-1.5.4 */
+/* #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000U */
+/* #define PNG_FLAG_KEEP_UNSAFE_CHUNKS      0x10000U */
+#define PNG_FLAG_LIBRARY_MISMATCH        0x20000U
+#define PNG_FLAG_STRIP_ERROR_NUMBERS     0x40000U
+#define PNG_FLAG_STRIP_ERROR_TEXT        0x80000U
+#define PNG_FLAG_BENIGN_ERRORS_WARN     0x100000U /* Added to libpng-1.4.0 */
+#define PNG_FLAG_APP_WARNINGS_WARN      0x200000U /* Added to libpng-1.6.0 */
+#define PNG_FLAG_APP_ERRORS_WARN        0x400000U /* Added to libpng-1.6.0 */
+                                  /*    0x800000U    unused */
+                                  /*   0x1000000U    unused */
+                                  /*   0x2000000U    unused */
+                                  /*   0x4000000U    unused */
+                                  /*   0x8000000U    unused */
+                                  /*  0x10000000U    unused */
+                                  /*  0x20000000U    unused */
+                                  /*  0x40000000U    unused */
+
+#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
+                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
+
+#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
+                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
+
+#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
+                                     PNG_FLAG_CRC_CRITICAL_MASK)
+
+/* Save typing and make code easier to understand */
+
+#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
+   abs((int)((c1).green) - (int)((c2).green)) + \
+   abs((int)((c1).blue) - (int)((c2).blue)))
+
+/* Added to libpng-1.6.0: scale a 16-bit value in the range 0..65535 to 0..255
+ * by dividing by 257 *with rounding*.  This macro is exact for the given range.
+ * See the discourse in pngrtran.c png_do_scale_16_to_8.  The values in the
+ * macro were established by experiment (modifying the added value).  The macro
+ * has a second variant that takes a value already scaled by 255 and divides by
+ * 65535 - this has a maximum error of .502.  Over the range 0..65535*65535 it
+ * only gives off-by-one errors and only for 0.5% (1 in 200) of the values.
+ */
+#define PNG_DIV65535(v24) (((v24) + 32895) >> 16)
+#define PNG_DIV257(v16) PNG_DIV65535((png_uint_32)(v16) * 255)
+
+/* Added to libpng-1.2.6 JB */
+#define PNG_ROWBYTES(pixel_bits, width) \
+    ((pixel_bits) >= 8 ? \
+    ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \
+    (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) )
+
+/* This returns the number of trailing bits in the last byte of a row, 0 if the
+ * last byte is completely full of pixels.  It is, in principle, (pixel_bits x
+ * width) % 8, but that would overflow for large 'width'.  The second macro is
+ * the same except that it returns the number of unused bits in the last byte;
+ * (8-TRAILBITS), but 0 when TRAILBITS is 0.
+ *
+ * NOTE: these macros are intended to be self-evidently correct and never
+ * overflow on the assumption that pixel_bits is in the range 0..255.  The
+ * arguments are evaluated only once and they can be signed (e.g. as a result of
+ * the integral promotions).  The result of the expression always has type
+ * (png_uint_32), however the compiler always knows it is in the range 0..7.
+ */
+#define PNG_TRAILBITS(pixel_bits, width) \
+    (((pixel_bits) * ((width) % (png_uint_32)8)) % 8)
+
+#define PNG_PADBITS(pixel_bits, width) \
+    ((8 - PNG_TRAILBITS(pixel_bits, width)) % 8)
+
+/* PNG_OUT_OF_RANGE returns true if value is outside the range
+ * ideal-delta..ideal+delta.  Each argument is evaluated twice.
+ * "ideal" and "delta" should be constants, normally simple
+ * integers, "value" a variable. Added to libpng-1.2.6 JB
+ */
+#define PNG_OUT_OF_RANGE(value, ideal, delta) \
+   ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
+
+/* Conversions between fixed and floating point, only defined if
+ * required (to make sure the code doesn't accidentally use float
+ * when it is supposedly disabled.)
+ */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* The floating point conversion can't overflow, though it can and
+ * does lose accuracy relative to the original fixed point value.
+ * In practice this doesn't matter because png_fixed_point only
+ * stores numbers with very low precision.  The png_ptr and s
+ * arguments are unused by default but are there in case error
+ * checking becomes a requirement.
+ */
+#define png_float(png_ptr, fixed, s) (.00001 * (fixed))
+
+/* The fixed point conversion performs range checking and evaluates
+ * its argument multiple times, so must be used with care.  The
+ * range checking uses the PNG specification values for a signed
+ * 32-bit fixed point value except that the values are deliberately
+ * rounded-to-zero to an integral value - 21474 (21474.83 is roughly
+ * (2^31-1) * 100000). 's' is a string that describes the value being
+ * converted.
+ *
+ * NOTE: this macro will raise a png_error if the range check fails,
+ * therefore it is normally only appropriate to use this on values
+ * that come from API calls or other sources where an out of range
+ * error indicates a programming error, not a data error!
+ *
+ * NOTE: by default this is off - the macro is not used - because the
+ * function call saves a lot of code.
+ */
+#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED
+#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\
+    ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0))
+#endif
+/* else the corresponding function is defined below, inside the scope of the
+ * cplusplus test.
+ */
+#endif
+
+/* Constants for known chunk types.  If you need to add a chunk, define the name
+ * here.  For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case.  Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.
+ *
+ * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
+ * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
+ * to be generated if required.
+ *
+ * PNG_32b correctly produces a value shifted by up to 24 bits, even on
+ * architectures where (int) is only 16 bits.
+ */
+#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
+#define PNG_U32(b1,b2,b3,b4) \
+   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+
+/* Constants for known chunk types.
+ *
+ * MAINTAINERS: If you need to add a chunk, define the name here.
+ * For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case.  Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.  Please keep the list sorted.
+ *
+ * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
+ * type.  In fact the specification does not express chunk types this way,
+ * however using a 32-bit value means that the chunk type can be read from the
+ * stream using exactly the same code as used for a 32-bit unsigned value and
+ * can be examined far more efficiently (using one arithmetic compare).
+ *
+ * Prior to 1.5.6 the chunk type constants were expressed as C strings.  The
+ * libpng API still uses strings for 'unknown' chunks and a macro,
+ * PNG_STRING_FROM_CHUNK, allows a string to be generated if required.  Notice
+ * that for portable code numeric values must still be used; the string "IHDR"
+ * is not portable and neither is PNG_U32('I', 'H', 'D', 'R').
+ *
+ * In 1.7.0 the definitions will be made public in png.h to avoid having to
+ * duplicate the same definitions in application code.
+ */
+#define png_IDAT PNG_U32( 73,  68,  65,  84)
+#define png_IEND PNG_U32( 73,  69,  78,  68)
+#define png_IHDR PNG_U32( 73,  72,  68,  82)
+#define png_PLTE PNG_U32( 80,  76,  84,  69)
+#define png_bKGD PNG_U32( 98,  75,  71,  68)
+#define png_cHRM PNG_U32( 99,  72,  82,  77)
+#define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
+#define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
+#define png_gAMA PNG_U32(103,  65,  77,  65)
+#define png_gIFg PNG_U32(103,  73,  70, 103)
+#define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
+#define png_gIFx PNG_U32(103,  73,  70, 120)
+#define png_hIST PNG_U32(104,  73,  83,  84)
+#define png_iCCP PNG_U32(105,  67,  67,  80)
+#define png_iTXt PNG_U32(105,  84,  88, 116)
+#define png_oFFs PNG_U32(111,  70,  70, 115)
+#define png_pCAL PNG_U32(112,  67,  65,  76)
+#define png_pHYs PNG_U32(112,  72,  89, 115)
+#define png_sBIT PNG_U32(115,  66,  73,  84)
+#define png_sCAL PNG_U32(115,  67,  65,  76)
+#define png_sPLT PNG_U32(115,  80,  76,  84)
+#define png_sRGB PNG_U32(115,  82,  71,  66)
+#define png_sTER PNG_U32(115,  84,  69,  82)
+#define png_tEXt PNG_U32(116,  69,  88, 116)
+#define png_tIME PNG_U32(116,  73,  77,  69)
+#define png_tRNS PNG_U32(116,  82,  78,  83)
+#define png_zTXt PNG_U32(122,  84,  88, 116)
+
+/* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+#define PNG_CHUNK_FROM_STRING(s)\
+   PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
+
+/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
+ * signed and the argument is a (char[])  This macro will fail miserably on
+ * systems where (char) is more than 8 bits.
+ */
+#define PNG_STRING_FROM_CHUNK(s,c)\
+   (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
+   ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
+   ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
+   ((char*)(s))[3]=(char)((c & 0xff)))
+
+/* Do the same but terminate with a null character. */
+#define PNG_CSTRING_FROM_CHUNK(s,c)\
+   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
+
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLARY(c)   (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
+#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
+#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
+#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
+
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
+
+/* Almost everything below is C specific; the #defines above can be used in
+ * non-C code (so long as it is C-preprocessed) the rest of this stuff cannot.
+ */
+#ifndef PNG_VERSION_INFO_ONLY
+
+#include "pngstruct.h"
+#include "pnginfo.h"
+
+/* Validate the include paths - the include path used to generate pnglibconf.h
+ * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
+ */
+#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
+#  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
+      "-I (include path) error: see the notes in pngpriv.h"
+   /* This means that when pnglibconf.h was built the copy of zlib.h that it
+    * used is not the same as the one being used here.  Because the build of
+    * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
+    * zlib version number and because this affects handling of certain broken
+    * PNG files the -I directives must match.
+    *
+    * The most likely explanation is that you passed a -I in CFLAGS. This will
+    * not work; all the preprocessor directories and in particular all the -I
+    * directives must be in CPPFLAGS.
+    */
+#endif
+
+/* This is used for 16-bit gamma tables -- only the top level pointers are
+ * const; this could be changed:
+ */
+typedef const png_uint_16p * png_const_uint_16pp;
+
+/* Added to libpng-1.5.7: sRGB conversion tables */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
+   /* Convert from an sRGB encoded value 0..255 to a 16-bit linear value,
+    * 0..65535.  This table gives the closest 16-bit answers (no errors).
+    */
+#endif
+
+PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
+PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
+
+#define PNG_sRGB_FROM_LINEAR(linear) \
+  ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
+   + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
+   /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
+    * encoded value with maximum error 0.646365.  Note that the input is not a
+    * 16-bit value; it has been multiplied by 255! */
+#endif /* SIMPLIFIED_READ/WRITE */
+
+
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* Internal functions; these are not exported from a DLL however because they
+ * are used within several of the C source files they have to be C extern.
+ *
+ * All of these functions must be declared with PNG_INTERNAL_FUNCTION.
+ */
+
+/* Zlib support */
+#define PNG_UNEXPECTED_ZLIB_RETURN (-7)
+PNG_INTERNAL_FUNCTION(void, png_zstream_error,(png_structrp png_ptr, int ret),
+   PNG_EMPTY);
+   /* Used by the zlib handling functions to ensure that z_stream::msg is always
+    * set before they return.
+    */
+
+#ifdef PNG_WRITE_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_free_buffer_list,(png_structrp png_ptr,
+   png_compression_bufferp *list),PNG_EMPTY);
+   /* Free the buffer list used by the compressed write code. */
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) && \
+   (defined(PNG_gAMA_SUPPORTED) || defined(PNG_cHRM_SUPPORTED) || \
+   defined(PNG_sCAL_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)) || \
+   (defined(PNG_sCAL_SUPPORTED) && \
+   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED))
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_fixed,(png_const_structrp png_ptr,
+   double fp, png_const_charp text),PNG_EMPTY);
+#endif
+
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_INTERNAL_FUNCTION(int,png_user_version_check,(png_structrp png_ptr,
+   png_const_charp user_png_ver),PNG_EMPTY);
+
+/* Internal base allocator - no messages, NULL on failure to allocate.  This
+ * does, however, call the application provided allocator and that could call
+ * png_error (although that would be a bug in the application implementation.)
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
+   png_alloc_size_t size),PNG_ALLOCATED);
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* Internal array allocator, outputs no error or warning messages on failure,
+ * just returns NULL.
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
+   int nelements, size_t element_size),PNG_ALLOCATED);
+
+/* The same but an existing array is extended by add_elements.  This function
+ * also memsets the new elements to 0 and copies the old elements.  The old
+ * array is not freed or altered.
+ */
+PNG_INTERNAL_FUNCTION(png_voidp,png_realloc_array,(png_const_structrp png_ptr,
+   png_const_voidp array, int old_elements, int add_elements,
+   size_t element_size),PNG_ALLOCATED);
+#endif /* text, sPLT or unknown chunks */
+
+/* Magic to create a struct when there is no struct to call the user supplied
+ * memory allocators.  Because error handling has not been set up the memory
+ * handlers can't safely call png_error, but this is an obscure and undocumented
+ * restriction so libpng has to assume that the 'free' handler, at least, might
+ * call png_error.
+ */
+PNG_INTERNAL_FUNCTION(png_structp,png_create_png_struct,
+   (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+    png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
+    png_free_ptr free_fn),PNG_ALLOCATED);
+
+/* Free memory from internal libpng struct */
+PNG_INTERNAL_FUNCTION(void,png_destroy_png_struct,(png_structrp png_ptr),
+   PNG_EMPTY);
+
+/* Free an allocated jmp_buf (always succeeds) */
+PNG_INTERNAL_FUNCTION(void,png_free_jmpbuf,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Function to allocate memory for zlib.  PNGAPI is disallowed. */
+PNG_INTERNAL_FUNCTION(voidpf,png_zalloc,(voidpf png_ptr, uInt items, uInt size),
+   PNG_ALLOCATED);
+
+/* Function to free memory for zlib.  PNGAPI is disallowed. */
+PNG_INTERNAL_FUNCTION(void,png_zfree,(voidpf png_ptr, voidpf ptr),PNG_EMPTY);
+
+/* Next four functions are used internally as callbacks.  PNGCBAPI is required
+ * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3, changed to
+ * PNGCBAPI at 1.5.0
+ */
+
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_read_data,(png_structp png_ptr,
+    png_bytep data, png_size_t length),PNG_EMPTY);
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_push_fill_buffer,(png_structp png_ptr,
+    png_bytep buffer, png_size_t length),PNG_EMPTY);
+#endif
+
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_write_data,(png_structp png_ptr,
+    png_bytep data, png_size_t length),PNG_EMPTY);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_STDIO_SUPPORTED
+PNG_INTERNAL_FUNCTION(void PNGCBAPI,png_default_flush,(png_structp png_ptr),
+   PNG_EMPTY);
+#  endif
+#endif
+
+/* Reset the CRC variable */
+PNG_INTERNAL_FUNCTION(void,png_reset_crc,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Write the "data" buffer to whatever output you are using */
+PNG_INTERNAL_FUNCTION(void,png_write_data,(png_structrp png_ptr,
+    png_const_bytep data, png_size_t length),PNG_EMPTY);
+
+/* Read and check the PNG file signature */
+PNG_INTERNAL_FUNCTION(void,png_read_sig,(png_structrp png_ptr,
+   png_inforp info_ptr),PNG_EMPTY);
+
+/* Read the chunk header (length + type name) */
+PNG_INTERNAL_FUNCTION(png_uint_32,png_read_chunk_header,(png_structrp png_ptr),
+   PNG_EMPTY);
+
+/* Read data from whatever input you are using into the "data" buffer */
+PNG_INTERNAL_FUNCTION(void,png_read_data,(png_structrp png_ptr, png_bytep data,
+    png_size_t length),PNG_EMPTY);
+
+/* Read bytes into buf, and update png_ptr->crc */
+PNG_INTERNAL_FUNCTION(void,png_crc_read,(png_structrp png_ptr, png_bytep buf,
+    png_uint_32 length),PNG_EMPTY);
+
+/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
+PNG_INTERNAL_FUNCTION(int,png_crc_finish,(png_structrp png_ptr,
+   png_uint_32 skip),PNG_EMPTY);
+
+/* Read the CRC from the file and compare it to the libpng calculated CRC */
+PNG_INTERNAL_FUNCTION(int,png_crc_error,(png_structrp png_ptr),PNG_EMPTY);
+
+/* Calculate the CRC over a section of data.  Note that we are only
+ * passing a maximum of 64K on systems that have this as a memory limit,
+ * since this is the maximum buffer size we can specify.
+ */
+PNG_INTERNAL_FUNCTION(void,png_calculate_crc,(png_structrp png_ptr,
+   png_const_bytep ptr, png_size_t length),PNG_EMPTY);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_flush,(png_structrp png_ptr),PNG_EMPTY);
+#endif
+
+/* Write various chunks */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.
+ */
+PNG_INTERNAL_FUNCTION(void,png_write_IHDR,(png_structrp png_ptr,
+   png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
+   int compression_method, int filter_method, int interlace_method),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_write_PLTE,(png_structrp png_ptr,
+   png_const_colorp palette, png_uint_32 num_pal),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_compress_IDAT,(png_structrp png_ptr,
+   png_const_bytep row_data, png_alloc_size_t row_data_length, int flush),
+   PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_write_IEND,(png_structrp png_ptr),PNG_EMPTY);
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_gAMA_fixed,(png_structrp png_ptr,
+    png_fixed_point file_gamma),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sBIT,(png_structrp png_ptr,
+    png_const_color_8p sbit, int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_cHRM_fixed,(png_structrp png_ptr,
+    const png_xy *xy), PNG_EMPTY);
+   /* The xy value must have been previously validated */
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
+    int intent),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
+    png_bytep exif, int num_exif),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
+   png_const_charp name, png_const_bytep profile), PNG_EMPTY);
+   /* The profile must have been previously validated for correctness, the
+    * length comes from the first four bytes.  Only the base, deflate,
+    * compression is supported.
+    */
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
+    png_const_sPLT_tp palette),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tRNS,(png_structrp png_ptr,
+    png_const_bytep trans, png_const_color_16p values, int number,
+    int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_bKGD,(png_structrp png_ptr,
+    png_const_color_16p values, int color_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_hIST,(png_structrp png_ptr,
+    png_const_uint_16p hist, int num_hist),PNG_EMPTY);
+#endif
+
+/* Chunks that have keywords */
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
+   png_const_charp key, png_const_charp text, png_size_t text_len),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
+    key, png_const_charp text, int compression),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_iTXt,(png_structrp png_ptr,
+    int compression, png_const_charp key, png_const_charp lang,
+    png_const_charp lang_key, png_const_charp text),PNG_EMPTY);
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
+PNG_INTERNAL_FUNCTION(int,png_set_text_2,(png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_textp text_ptr, int num_text),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_oFFs,(png_structrp png_ptr,
+    png_int_32 x_offset, png_int_32 y_offset, int unit_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_pCAL,(png_structrp png_ptr,
+    png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
+    png_const_charp units, png_charpp params),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_pHYs,(png_structrp png_ptr,
+    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
+    int unit_type),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_tIME,(png_structrp png_ptr,
+    png_const_timep mod_time),PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_sCAL_s,(png_structrp png_ptr,
+    int unit, png_const_charp width, png_const_charp height),PNG_EMPTY);
+#endif
+
+/* Called when finished processing a row of data */
+PNG_INTERNAL_FUNCTION(void,png_write_finish_row,(png_structrp png_ptr),
+    PNG_EMPTY);
+
+/* Internal use only.   Called before first row of data */
+PNG_INTERNAL_FUNCTION(void,png_write_start_row,(png_structrp png_ptr),
+    PNG_EMPTY);
+
+/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
+ * array of png_ptr->width pixels.  If the image is not interlaced or this
+ * is the final pass this just does a memcpy, otherwise the "display" flag
+ * is used to determine whether to copy pixels that are not in the current pass.
+ *
+ * Because 'png_do_read_interlace' (below) replicates pixels this allows this
+ * function to achieve the documented 'blocky' appearance during interlaced read
+ * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
+ * are not changed if they are not in the current pass, when display is 0.
+ *
+ * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
+ *
+ * The API always reads from the png_struct row buffer and always assumes that
+ * it is full width (png_do_read_interlace has already been called.)
+ *
+ * This function is only ever used to write to row buffers provided by the
+ * caller of the relevant libpng API and the row must have already been
+ * transformed by the read transformations.
+ *
+ * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
+ * bitmasks for use within the code, otherwise runtime generated masks are used.
+ * The default is compile time masks.
+ */
+#ifndef PNG_USE_COMPILE_TIME_MASKS
+#  define PNG_USE_COMPILE_TIME_MASKS 1
+#endif
+PNG_INTERNAL_FUNCTION(void,png_combine_row,(png_const_structrp png_ptr,
+    png_bytep row, int display),PNG_EMPTY);
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+/* Expand an interlaced row: the 'row_info' describes the pass data that has
+ * been read in and must correspond to the pixels in 'row', the pixels are
+ * expanded (moved apart) in 'row' to match the final layout, when doing this
+ * the pixels are *replicated* to the intervening space.  This is essential for
+ * the correct operation of png_combine_row, above.
+ */
+PNG_INTERNAL_FUNCTION(void,png_do_read_interlace,(png_row_infop row_info,
+    png_bytep row, int pass, png_uint_32 transformations),PNG_EMPTY);
+#endif
+
+/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Grab pixels out of a row for an interlaced pass */
+PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
+    png_bytep row, int pass),PNG_EMPTY);
+#endif
+
+/* Unfilter a row: check the filter value before calling this, there is no point
+ * calling it for PNG_FILTER_VALUE_NONE.
+ */
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
+
+#if PNG_ARM_NEON_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_MIPS_MSA_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_msa,(png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_msa,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_msa,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_msa,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_msa,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_msa,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_msa,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_POWERPC_VSX_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_vsx,(png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_vsx,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_vsx,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_vsx,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_vsx,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_vsx,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_vsx,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
+    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
+#endif
+
+/* Choose the best filter to use and filter the row data */
+PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
+    png_row_infop row_info),PNG_EMPTY);
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
+   png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
+   /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
+    * is NULL the function checks, instead, for the end of the stream.  In this
+    * case a benign error will be issued if the stream end is not found or if
+    * extra data has to be consumed.
+    */
+PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
+   PNG_EMPTY);
+   /* This cleans up when the IDAT LZ stream does not end when the last image
+    * byte is read; there is still some pending input.
+    */
+
+PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
+   PNG_EMPTY);
+   /* Finish a row while reading, dealing with interlacing passes, etc. */
+#endif /* SEQUENTIAL_READ */
+
+/* Initialize the row buffers, etc. */
+PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
+
+#if ZLIB_VERNUM >= 0x1240
+PNG_INTERNAL_FUNCTION(int,png_zlib_inflate,(png_structrp png_ptr, int flush),
+      PNG_EMPTY);
+#  define PNG_INFLATE(pp, flush) png_zlib_inflate(pp, flush)
+#else /* Zlib < 1.2.4 */
+#  define PNG_INFLATE(pp, flush) inflate(&(pp)->zstream, flush)
+#endif /* Zlib < 1.2.4 */
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Optional call to update the users info structure */
+PNG_INTERNAL_FUNCTION(void,png_read_transform_info,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+#endif
+
+/* Shared transform functions, defined in pngtran.c */
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_strip_channel,(png_row_infop row_info,
+    png_bytep row, int at_start),PNG_EMPTY);
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_swap,(png_row_infop row_info,
+    png_bytep row),PNG_EMPTY);
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
+    defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_packswap,(png_row_infop row_info,
+    png_bytep row),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_invert,(png_row_infop row_info,
+    png_bytep row),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_bgr,(png_row_infop row_info,
+    png_bytep row),PNG_EMPTY);
+#endif
+
+/* The following decodes the appropriate chunks, and does error correction,
+ * then calls the appropriate callback for the chunk if it is valid.
+ */
+
+/* Decode the IHDR chunk */
+PNG_INTERNAL_FUNCTION(void,png_handle_IHDR,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_PLTE,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_handle_IEND,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_bKGD,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_cHRM,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_eXIf_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_eXIf,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_gAMA,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif /* READ_iCCP */
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_oFFs,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_pCAL,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_pHYs,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sBIT,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif /* READ_sPLT */
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_tEXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_tIME,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_tRNS,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif
+
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
+    const png_uint_32 chunk_name),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
+    const png_uint_32 chunk_length),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
+   /* This is the function that gets called for unknown chunks.  The 'keep'
+    * argument is either non-zero for a known chunk that has been set to be
+    * handled as unknown or zero for an unknown chunk.  By default the function
+    * just skips the chunk or errors out if it is critical.
+    */
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+    defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
+    (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
+   /* Exactly as the API png_handle_as_unknown() except that the argument is a
+    * 32-bit chunk name, not a string.
+    */
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
+
+/* Handle the transformations for reading and writing */
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_do_read_transformations,(png_structrp png_ptr,
+   png_row_infop row_info),PNG_EMPTY);
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_do_write_transformations,(png_structrp png_ptr,
+   png_row_infop row_info),PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_init_read_transformations,(png_structrp png_ptr),
+    PNG_EMPTY);
+#endif
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_read_chunk,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_sig,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_check_crc,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_save_buffer,(png_structrp png_ptr),
+    PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_restore_buffer,(png_structrp png_ptr,
+    png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_IDAT,(png_structrp png_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_process_IDAT_data,(png_structrp png_ptr,
+    png_bytep buffer, png_size_t buffer_length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_process_row,(png_structrp png_ptr),
+    PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_handle_unknown,(png_structrp png_ptr,
+   png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_info,(png_structrp png_ptr,
+   png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_end,(png_structrp png_ptr,
+   png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_have_row,(png_structrp png_ptr,
+    png_bytep row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_end,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_process_some_data,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_push_finish_row,(png_structrp png_ptr),
+    PNG_EMPTY);
+#  ifdef PNG_READ_tEXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_handle_tEXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_tEXt,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+#  endif
+#  ifdef PNG_READ_zTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_handle_zTXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_zTXt,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+#  endif
+#  ifdef PNG_READ_iTXt_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_push_handle_iTXt,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
+    png_inforp info_ptr),PNG_EMPTY);
+#  endif
+
+#endif /* PROGRESSIVE_READ */
+
+/* Added at libpng version 1.6.0 */
+#ifdef PNG_GAMMA_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
+    png_colorspacerp colorspace, png_fixed_point gAMA), PNG_EMPTY);
+   /* Set the colorspace gamma with a value provided by the application or by
+    * the gAMA chunk on read.  The value will override anything set by an ICC
+    * profile.
+    */
+
+PNG_INTERNAL_FUNCTION(void,png_colorspace_sync_info,(png_const_structrp png_ptr,
+    png_inforp info_ptr), PNG_EMPTY);
+   /* Synchronize the info 'valid' flags with the colorspace */
+
+PNG_INTERNAL_FUNCTION(void,png_colorspace_sync,(png_const_structrp png_ptr,
+    png_inforp info_ptr), PNG_EMPTY);
+   /* Copy the png_struct colorspace to the info_struct and call the above to
+    * synchronize the flags.  Checks for NULL info_ptr and does nothing.
+    */
+#endif
+
+/* Added at libpng version 1.4.0 */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* These internal functions are for maintaining the colorspace structure within
+ * a png_info or png_struct (or, indeed, both).
+ */
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_chromaticities,
+   (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_xy *xy,
+    int preferred), PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_endpoints,
+   (png_const_structrp png_ptr, png_colorspacerp colorspace, const png_XYZ *XYZ,
+    int preferred), PNG_EMPTY);
+
+#ifdef PNG_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_sRGB,(png_const_structrp png_ptr,
+   png_colorspacerp colorspace, int intent), PNG_EMPTY);
+   /* This does set the colorspace gAMA and cHRM values too, but doesn't set the
+    * flags to write them, if it returns false there was a problem and an error
+    * message has already been output (but the colorspace may still need to be
+    * synced to record the invalid flag).
+    */
+#endif /* sRGB */
+
+#ifdef PNG_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_colorspace_set_ICC,(png_const_structrp png_ptr,
+   png_colorspacerp colorspace, png_const_charp name,
+   png_uint_32 profile_length, png_const_bytep profile, int color_type),
+   PNG_EMPTY);
+   /* The 'name' is used for information only */
+
+/* Routines for checking parts of an ICC profile. */
+#ifdef PNG_READ_iCCP_SUPPORTED
+PNG_INTERNAL_FUNCTION(int,png_icc_check_length,(png_const_structrp png_ptr,
+   png_colorspacerp colorspace, png_const_charp name,
+   png_uint_32 profile_length), PNG_EMPTY);
+#endif /* READ_iCCP */
+PNG_INTERNAL_FUNCTION(int,png_icc_check_header,(png_const_structrp png_ptr,
+   png_colorspacerp colorspace, png_const_charp name,
+   png_uint_32 profile_length,
+   png_const_bytep profile /* first 132 bytes only */, int color_type),
+   PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(int,png_icc_check_tag_table,(png_const_structrp png_ptr,
+   png_colorspacerp colorspace, png_const_charp name,
+   png_uint_32 profile_length,
+   png_const_bytep profile /* header plus whole tag table */), PNG_EMPTY);
+#ifdef PNG_sRGB_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_icc_set_sRGB,(
+   png_const_structrp png_ptr, png_colorspacerp colorspace,
+   png_const_bytep profile, uLong adler), PNG_EMPTY);
+   /* 'adler' is the Adler32 checksum of the uncompressed profile data. It may
+    * be zero to indicate that it is not available.  It is used, if provided,
+    * as a fast check on the profile when checking to see if it is sRGB.
+    */
+#endif
+#endif /* iCCP */
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_colorspace_set_rgb_coefficients,
+   (png_structrp png_ptr), PNG_EMPTY);
+   /* Set the rgb_to_gray coefficients from the colorspace Y values */
+#endif /* READ_RGB_TO_GRAY */
+#endif /* COLORSPACE */
+
+/* Added at libpng version 1.4.0 */
+PNG_INTERNAL_FUNCTION(void,png_check_IHDR,(png_const_structrp png_ptr,
+    png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_type, int compression_type,
+    int filter_type),PNG_EMPTY);
+
+/* Added at libpng version 1.5.10 */
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_do_check_palette_indexes,
+   (png_structrp png_ptr, png_row_infop row_info),PNG_EMPTY);
+#endif
+
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
+PNG_INTERNAL_FUNCTION(void,png_fixed_error,(png_const_structrp png_ptr,
+   png_const_charp name),PNG_NORETURN);
+#endif
+
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end.  Always leaves the buffer nul terminated.  Never errors out (and
+ * there is no error code.)
+ */
+PNG_INTERNAL_FUNCTION(size_t,png_safecat,(png_charp buffer, size_t bufsize,
+   size_t pos, png_const_charp string),PNG_EMPTY);
+
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.  This utility only
+ * does unsigned values.
+ */
+PNG_INTERNAL_FUNCTION(png_charp,png_format_number,(png_const_charp start,
+   png_charp end, int format, png_alloc_size_t number),PNG_EMPTY);
+
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+   png_format_number(buffer, buffer + (sizeof buffer), format, number)
+
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u   2
+#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d   2
+#define PNG_NUMBER_FORMAT_x     3
+#define PNG_NUMBER_FORMAT_02x   4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+#  define PNG_WARNING_PARAMETER_SIZE 32
+#  define PNG_WARNING_PARAMETER_COUNT 8 /* Maximum 9; see pngerror.c */
+
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+   PNG_WARNING_PARAMETER_SIZE];
+
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter,(png_warning_parameters p,
+   int number, png_const_charp string),PNG_EMPTY);
+   /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+    * including the trailing '\0'.
+    */
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter_unsigned,
+   (png_warning_parameters p, int number, int format, png_alloc_size_t value),
+   PNG_EMPTY);
+   /* Use png_alloc_size_t because it is an unsigned type as big as any we
+    * need to output.  Use the following for a signed value.
+    */
+PNG_INTERNAL_FUNCTION(void,png_warning_parameter_signed,
+   (png_warning_parameters p, int number, int format, png_int_32 value),
+   PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_formatted_warning,(png_const_structrp png_ptr,
+   png_warning_parameters p, png_const_charp message),PNG_EMPTY);
+   /* 'message' follows the X/Open approach of using @1, @2 to insert
+    * parameters previously supplied using the above functions.  Errors in
+    * specifying the parameters will simply result in garbage substitutions.
+    */
+#endif
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+/* Application errors (new in 1.6); use these functions (declared below) for
+ * errors in the parameters or order of API function calls on read.  The
+ * 'warning' should be used for an error that can be handled completely; the
+ * 'error' for one which can be handled safely but which may lose application
+ * information or settings.
+ *
+ * By default these both result in a png_error call prior to release, while in a
+ * released version the 'warning' is just a warning.  However if the application
+ * explicitly disables benign errors (explicitly permitting the code to lose
+ * information) they both turn into warnings.
+ *
+ * If benign errors aren't supported they end up as the corresponding base call
+ * (png_warning or png_error.)
+ */
+PNG_INTERNAL_FUNCTION(void,png_app_warning,(png_const_structrp png_ptr,
+   png_const_charp message),PNG_EMPTY);
+   /* The application provided invalid parameters to an API function or called
+    * an API function at the wrong time, libpng can completely recover.
+    */
+
+PNG_INTERNAL_FUNCTION(void,png_app_error,(png_const_structrp png_ptr,
+   png_const_charp message),PNG_EMPTY);
+   /* As above but libpng will ignore the call, or attempt some other partial
+    * recovery from the error.
+    */
+#else
+#  define png_app_warning(pp,s) png_warning(pp,s)
+#  define png_app_error(pp,s) png_error(pp,s)
+#endif
+
+PNG_INTERNAL_FUNCTION(void,png_chunk_report,(png_const_structrp png_ptr,
+   png_const_charp message, int error),PNG_EMPTY);
+   /* Report a recoverable issue in chunk data.  On read this is used to report
+    * a problem found while reading a particular chunk and the
+    * png_chunk_benign_error or png_chunk_warning function is used as
+    * appropriate.  On write this is used to report an error that comes from
+    * data set via an application call to a png_set_ API and png_app_error or
+    * png_app_warning is used as appropriate.
+    *
+    * The 'error' parameter must have one of the following values:
+    */
+#define PNG_CHUNK_WARNING     0 /* never an error */
+#define PNG_CHUNK_WRITE_ERROR 1 /* an error only on write */
+#define PNG_CHUNK_ERROR       2 /* always an error */
+
+/* ASCII to FP interfaces, currently only implemented if sCAL
+ * support is required.
+ */
+#if defined(PNG_sCAL_SUPPORTED)
+/* MAX_DIGITS is actually the maximum number of characters in an sCAL
+ * width or height, derived from the precision (number of significant
+ * digits - a build time settable option) and assumptions about the
+ * maximum ridiculous exponent.
+ */
+#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/)
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_ascii_from_fp,(png_const_structrp png_ptr,
+   png_charp ascii, png_size_t size, double fp, unsigned int precision),
+   PNG_EMPTY);
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_ascii_from_fixed,(png_const_structrp png_ptr,
+   png_charp ascii, png_size_t size, png_fixed_point fp),PNG_EMPTY);
+#endif /* FIXED_POINT */
+#endif /* sCAL */
+
+#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED)
+/* An internal API to validate the format of a floating point number.
+ * The result is the index of the next character.  If the number is
+ * not valid it will be the index of a character in the supposed number.
+ *
+ * The format of a number is defined in the PNG extensions specification
+ * and this API is strictly conformant to that spec, not anyone elses!
+ *
+ * The format as a regular expression is:
+ *
+ * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)?
+ *
+ * or:
+ *
+ * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)?
+ *
+ * The complexity is that either integer or fraction must be present and the
+ * fraction is permitted to have no digits only if the integer is present.
+ *
+ * NOTE: The dangling E problem.
+ *   There is a PNG valid floating point number in the following:
+ *
+ *       PNG floating point numbers are not greedy.
+ *
+ *   Working this out requires *TWO* character lookahead (because of the
+ *   sign), the parser does not do this - it will fail at the 'r' - this
+ *   doesn't matter for PNG sCAL chunk values, but it requires more care
+ *   if the value were ever to be embedded in something more complex.  Use
+ *   ANSI-C strtod if you need the lookahead.
+ */
+/* State table for the parser. */
+#define PNG_FP_INTEGER    0  /* before or in integer */
+#define PNG_FP_FRACTION   1  /* before or in fraction */
+#define PNG_FP_EXPONENT   2  /* before or in exponent */
+#define PNG_FP_STATE      3  /* mask for the above */
+#define PNG_FP_SAW_SIGN   4  /* Saw +/- in current state */
+#define PNG_FP_SAW_DIGIT  8  /* Saw a digit in current state */
+#define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
+#define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
+#define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
+
+/* These three values don't affect the parser.  They are set but not used.
+ */
+#define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
+#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
+#define PNG_FP_NONZERO  256  /* A non-zero value */
+#define PNG_FP_STICKY   448  /* The above three flags */
+
+/* This is available for the caller to store in 'state' if required.  Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
+
+/* Result codes for the parser (boolean - true meants ok, false means
+ * not ok yet.)
+ */
+#define PNG_FP_MAYBE      0  /* The number may be valid in the future */
+#define PNG_FP_OK         1  /* The number is valid */
+
+/* Tests on the sticky non-zero and negative flags.  To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+   /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+   /* Z MASK: the string is valid and a non-zero value. */
+   /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+
+/* The actual parser.  This can be called repeatedly. It updates
+ * the index into the string and the state variable (which must
+ * be initialized to 0).  It returns a result code, as above.  There
+ * is no point calling the parser any more if it fails to advance to
+ * the end of the string - it is stuck on an invalid character (or
+ * terminated by '\0').
+ *
+ * Note that the pointer will consume an E or even an E+ and then leave
+ * a 'maybe' state even though a preceding integer.fraction is valid.
+ * The PNG_FP_WAS_VALID flag indicates that a preceding substring was
+ * a valid number.  It's possible to recover from this by calling
+ * the parser again (from the start, with state 0) but with a string
+ * that omits the last character (i.e. set the size to the index of
+ * the problem character.)  This has not been tested within libpng.
+ */
+PNG_INTERNAL_FUNCTION(int,png_check_fp_number,(png_const_charp string,
+   png_size_t size, int *statep, png_size_tp whereami),PNG_EMPTY);
+
+/* This is the same but it checks a complete string and returns true
+ * only if it just contains a floating point number.  As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.)  This can be used for testing
+ * for negative or zero values using the sticky flag.
+ */
+PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
+   png_size_t size),PNG_EMPTY);
+#endif /* pCAL || sCAL */
+
+#if defined(PNG_GAMMA_SUPPORTED) ||\
+    defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
+/* Added at libpng version 1.5.0 */
+/* This is a utility to provide a*times/div (rounded) and indicate
+ * if there is an overflow.  The result is a boolean - false (0)
+ * for overflow, true (1) if no overflow, in which case *res
+ * holds the result.
+ */
+PNG_INTERNAL_FUNCTION(int,png_muldiv,(png_fixed_point_p res, png_fixed_point a,
+   png_int_32 multiplied_by, png_int_32 divided_by),PNG_EMPTY);
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
+/* Same deal, but issue a warning on overflow and return 0. */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_muldiv_warn,
+   (png_const_structrp png_ptr, png_fixed_point a, png_int_32 multiplied_by,
+   png_int_32 divided_by),PNG_EMPTY);
+#endif
+
+#ifdef PNG_GAMMA_SUPPORTED
+/* Calculate a reciprocal - used for gamma values.  This returns
+ * 0 if the argument is 0 in order to maintain an undefined value;
+ * there are no warnings.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal,(png_fixed_point a),
+   PNG_EMPTY);
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* The same but gives a reciprocal of the product of two fixed point
+ * values.  Accuracy is suitable for gamma calculations but this is
+ * not exact - use png_muldiv for that.  Only required at present on read.
+ */
+PNG_INTERNAL_FUNCTION(png_fixed_point,png_reciprocal2,(png_fixed_point a,
+   png_fixed_point b),PNG_EMPTY);
+#endif
+
+/* Return true if the gamma value is significantly different from 1.0 */
+PNG_INTERNAL_FUNCTION(int,png_gamma_significant,(png_fixed_point gamma_value),
+   PNG_EMPTY);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Internal fixed point gamma correction.  These APIs are called as
+ * required to convert single values - they don't need to be fast,
+ * they are not used when processing image pixel values.
+ *
+ * While the input is an 'unsigned' value it must actually be the
+ * correct bit value - 0..255 or 0..65535 as required.
+ */
+PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_correct,(png_structrp png_ptr,
+   unsigned int value, png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(png_uint_16,png_gamma_16bit_correct,(unsigned int value,
+   png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(png_byte,png_gamma_8bit_correct,(unsigned int value,
+   png_fixed_point gamma_value),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_destroy_gamma_table,(png_structrp png_ptr),
+   PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_build_gamma_table,(png_structrp png_ptr,
+   int bit_depth),PNG_EMPTY);
+#endif
+
+/* SIMPLIFIED READ/WRITE SUPPORT */
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+/* The internal structure that png_image::opaque points to. */
+typedef struct png_control
+{
+   png_structp png_ptr;
+   png_infop   info_ptr;
+   png_voidp   error_buf;           /* Always a jmp_buf at present. */
+
+   png_const_bytep memory;          /* Memory buffer. */
+   png_size_t      size;            /* Size of the memory buffer. */
+
+   unsigned int for_write       :1; /* Otherwise it is a read structure */
+   unsigned int owned_file      :1; /* We own the file in io_ptr */
+} png_control;
+
+/* Return the pointer to the jmp_buf from a png_control: necessary because C
+ * does not reveal the type of the elements of jmp_buf.
+ */
+#ifdef __cplusplus
+#  define png_control_jmp_buf(pc) (((jmp_buf*)((pc)->error_buf))[0])
+#else
+#  define png_control_jmp_buf(pc) ((pc)->error_buf)
+#endif
+
+/* Utility to safely execute a piece of libpng code catching and logging any
+ * errors that might occur.  Returns true on success, false on failure (either
+ * of the function or as a result of a png_error.)
+ */
+PNG_INTERNAL_CALLBACK(void,png_safe_error,(png_structp png_ptr,
+   png_const_charp error_message),PNG_NORETURN);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+PNG_INTERNAL_CALLBACK(void,png_safe_warning,(png_structp png_ptr,
+   png_const_charp warning_message),PNG_EMPTY);
+#else
+#  define png_safe_warning 0/*dummy argument*/
+#endif
+
+PNG_INTERNAL_FUNCTION(int,png_safe_execute,(png_imagep image,
+   int (*function)(png_voidp), png_voidp arg),PNG_EMPTY);
+
+/* Utility to log an error; this also cleans up the png_image; the function
+ * always returns 0 (false).
+ */
+PNG_INTERNAL_FUNCTION(int,png_image_error,(png_imagep image,
+   png_const_charp error_message),PNG_EMPTY);
+
+#ifndef PNG_SIMPLIFIED_READ_SUPPORTED
+/* png_image_free is used by the write code but not exported */
+PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
+#endif /* !SIMPLIFIED_READ */
+
+#endif /* SIMPLIFIED READ/WRITE */
+
+/* These are initialization functions for hardware specific PNG filter
+ * optimizations; list these here then select the appropriate one at compile
+ * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
+ * the generic code is used.
+ */
+#ifdef PNG_FILTER_OPTIMIZATIONS
+PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
+   unsigned int bpp), PNG_EMPTY);
+   /* Just declare the optimization that will be used */
+#else
+   /* List *all* the possible optimizations here - this branch is required if
+    * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
+    * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
+    */
+#  if PNG_ARM_NEON_OPT > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
+   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+#if PNG_MIPS_MSA_OPT > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_msa,
+   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#endif
+
+#  if PNG_INTEL_SSE_IMPLEMENTATION > 0
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
+   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
+#  endif
+#endif
+
+PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
+   png_const_charp key, png_bytep new_key), PNG_EMPTY);
+
+/* Maintainer: Put new private prototypes here ^ */
+
+#include "pngdebug.h"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PNG_VERSION_INFO_ONLY */
+#endif /* PNGPRIV_H */
diff --git a/xs/src/png/libpng/pngread.c b/xs/src/png/libpng/pngread.c
new file mode 100644
index 000000000..da32e9ad9
--- /dev/null
+++ b/xs/src/png/libpng/pngread.c
@@ -0,0 +1,4219 @@
+
+/* pngread.c - read a PNG file
+ *
+ * Last changed in libpng 1.6.33 [September 28, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that an application calls directly to
+ * read a PNG file or stream.
+ */
+
+#include "pngpriv.h"
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+#  include <errno.h>
+#endif
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Create a PNG structure for reading, and allocate any memory needed. */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+   png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+        error_fn, warn_fn, NULL, NULL, NULL);
+#else
+   return png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+        warn_fn, NULL, NULL, NULL);
+}
+
+/* Alternate create PNG structure for reading, and allocate any memory
+ * needed.
+ */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+   png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+#endif /* USER_MEM */
+
+   if (png_ptr != NULL)
+   {
+      png_ptr->mode = PNG_IS_READ_STRUCT;
+
+      /* Added in libpng-1.6.0; this can be used to detect a read structure if
+       * required (it will be zero in a write structure.)
+       */
+#     ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+         png_ptr->IDAT_read_size = PNG_IDAT_READ_SIZE;
+#     endif
+
+#     ifdef PNG_BENIGN_READ_ERRORS_SUPPORTED
+         png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+
+         /* In stable builds only warn if an application error can be completely
+          * handled.
+          */
+#        if PNG_RELEASE_BUILD
+            png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+#        endif
+#     endif
+
+      /* TODO: delay this, it can be done in png_init_io (if the app doesn't
+       * do it itself) avoiding setting the default function if it is not
+       * required.
+       */
+      png_set_read_fn(png_ptr, NULL, NULL);
+   }
+
+   return png_ptr;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the information before the actual image data.  This has been
+ * changed in v0.90 to allow reading a file that already has the magic
+ * bytes read from the stream.  You can tell libpng how many bytes have
+ * been read from the beginning of the stream (up to the maximum of 8)
+ * via png_set_sig_bytes(), and we will only check the remaining bytes
+ * here.  The application can then have access to the signature bytes we
+ * read if it is determined that this isn't a valid PNG file.
+ */
+void PNGAPI
+png_read_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep;
+#endif
+
+   png_debug(1, "in png_read_info");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   /* Read and check the PNG file signature. */
+   png_read_sig(png_ptr, info_ptr);
+
+   for (;;)
+   {
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      png_uint_32 chunk_name = png_ptr->chunk_name;
+
+      /* IDAT logic needs to happen here to simplify getting the two flags
+       * right.
+       */
+      if (chunk_name == png_IDAT)
+      {
+         if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+            png_chunk_error(png_ptr, "Missing IHDR before IDAT");
+
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+             (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+            png_chunk_error(png_ptr, "Missing PLTE before IDAT");
+
+         else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
+            png_chunk_benign_error(png_ptr, "Too many IDATs found");
+
+         png_ptr->mode |= PNG_HAVE_IDAT;
+      }
+
+      else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+      {
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+         png_ptr->mode |= PNG_AFTER_IDAT;
+      }
+
+      /* This should be a binary subdivision search or a hash for
+       * matching the chunk name rather than a linear search.
+       */
+      if (chunk_name == png_IHDR)
+         png_handle_IHDR(png_ptr, info_ptr, length);
+
+      else if (chunk_name == png_IEND)
+         png_handle_IEND(png_ptr, info_ptr, length);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+      {
+         png_handle_unknown(png_ptr, info_ptr, length, keep);
+
+         if (chunk_name == png_PLTE)
+            png_ptr->mode |= PNG_HAVE_PLTE;
+
+         else if (chunk_name == png_IDAT)
+         {
+            png_ptr->idat_size = 0; /* It has been consumed */
+            break;
+         }
+      }
+#endif
+      else if (chunk_name == png_PLTE)
+         png_handle_PLTE(png_ptr, info_ptr, length);
+
+      else if (chunk_name == png_IDAT)
+      {
+         png_ptr->idat_size = length;
+         break;
+      }
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+      else if (chunk_name == png_bKGD)
+         png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+      else if (chunk_name == png_cHRM)
+         png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_eXIf_SUPPORTED
+      else if (chunk_name == png_eXIf)
+         png_handle_eXIf(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+      else if (chunk_name == png_gAMA)
+         png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+      else if (chunk_name == png_hIST)
+         png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+      else if (chunk_name == png_oFFs)
+         png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+      else if (chunk_name == png_pCAL)
+         png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+      else if (chunk_name == png_sCAL)
+         png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+      else if (chunk_name == png_pHYs)
+         png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+      else if (chunk_name == png_sBIT)
+         png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+      else if (chunk_name == png_sRGB)
+         png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+      else if (chunk_name == png_iCCP)
+         png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+      else if (chunk_name == png_sPLT)
+         png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+      else if (chunk_name == png_tEXt)
+         png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+      else if (chunk_name == png_tIME)
+         png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+      else if (chunk_name == png_tRNS)
+         png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+      else if (chunk_name == png_zTXt)
+         png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+      else if (chunk_name == png_iTXt)
+         png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+
+      else
+         png_handle_unknown(png_ptr, info_ptr, length,
+             PNG_HANDLE_CHUNK_AS_DEFAULT);
+   }
+}
+#endif /* SEQUENTIAL_READ */
+
+/* Optional call to update the users info_ptr structure */
+void PNGAPI
+png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+   png_debug(1, "in png_read_update_info");
+
+   if (png_ptr != NULL)
+   {
+      if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+      {
+         png_read_start_row(png_ptr);
+
+#        ifdef PNG_READ_TRANSFORMS_SUPPORTED
+            png_read_transform_info(png_ptr, info_ptr);
+#        else
+            PNG_UNUSED(info_ptr)
+#        endif
+      }
+
+      /* New in 1.6.0 this avoids the bug of doing the initializations twice */
+      else
+         png_app_error(png_ptr,
+             "png_read_update_info/png_start_read_image: duplicate call");
+   }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Initialize palette, background, etc, after transformations
+ * are set, but before any reading takes place.  This allows
+ * the user to obtain a gamma-corrected palette, for example.
+ * If the user doesn't call this, we will do it ourselves.
+ */
+void PNGAPI
+png_start_read_image(png_structrp png_ptr)
+{
+   png_debug(1, "in png_start_read_image");
+
+   if (png_ptr != NULL)
+   {
+      if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+         png_read_start_row(png_ptr);
+
+      /* New in 1.6.0 this avoids the bug of doing the initializations twice */
+      else
+         png_app_error(png_ptr,
+             "png_start_read_image/png_read_update_info: duplicate call");
+   }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing,
+ * NOTE: this is apparently only supported in the 'sequential' reader.
+ */
+static void
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_read_intrapixel");
+
+   if (
+       (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      int bytes_per_pixel;
+      png_uint_32 row_width = row_info->width;
+
+      if (row_info->bit_depth == 8)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 3;
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 4;
+
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff);
+            *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff);
+         }
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 6;
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 8;
+
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            png_uint_32 s0   = (png_uint_32)(*(rp    ) << 8) | *(rp + 1);
+            png_uint_32 s1   = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3);
+            png_uint_32 s2   = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5);
+            png_uint_32 red  = (s0 + s1 + 65536) & 0xffff;
+            png_uint_32 blue = (s2 + s1 + 65536) & 0xffff;
+            *(rp    ) = (png_byte)((red >> 8) & 0xff);
+            *(rp + 1) = (png_byte)(red & 0xff);
+            *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+            *(rp + 5) = (png_byte)(blue & 0xff);
+         }
+      }
+   }
+}
+#endif /* MNG_FEATURES */
+
+void PNGAPI
+png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
+{
+   png_row_info row_info;
+
+   if (png_ptr == NULL)
+      return;
+
+   png_debug2(1, "in png_read_row (row %lu, pass %d)",
+       (unsigned long)png_ptr->row_number, png_ptr->pass);
+
+   /* png_read_start_row sets the information (in particular iwidth) for this
+    * interlace pass.
+    */
+   if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+      png_read_start_row(png_ptr);
+
+   /* 1.5.6: row_info moved out of png_struct to a local here. */
+   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
+   row_info.color_type = png_ptr->color_type;
+   row_info.bit_depth = png_ptr->bit_depth;
+   row_info.channels = png_ptr->channels;
+   row_info.pixel_depth = png_ptr->pixel_depth;
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+#ifdef PNG_WARNINGS_SUPPORTED
+   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+   {
+   /* Check for transforms that have been set but were defined out */
+#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+      png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+    !defined(PNG_READ_PACKSWAP_SUPPORTED)
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+      png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
+   if ((png_ptr->transformations & PNG_PACK) != 0)
+      png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
+      png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
+   if ((png_ptr->transformations & PNG_BGR) != 0)
+      png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
+#endif
+
+#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+      png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
+#endif
+   }
+#endif /* WARNINGS */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* If interlaced and we do not need a new row, combine row and return.
+    * Notice that the pixels we have from previous rows have been transformed
+    * already; we can only combine like with like (transformed or
+    * untransformed) and, because of the libpng API for interlaced images, this
+    * means we must transform before de-interlacing.
+    */
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
+   {
+      switch (png_ptr->pass)
+      {
+         case 0:
+            if (png_ptr->row_number & 0x07)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 1:
+            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 2:
+            if ((png_ptr->row_number & 0x07) != 4)
+            {
+               if (dsp_row != NULL && (png_ptr->row_number & 4))
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 3:
+            if ((png_ptr->row_number & 3) || png_ptr->width < 3)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 4:
+            if ((png_ptr->row_number & 3) != 2)
+            {
+               if (dsp_row != NULL && (png_ptr->row_number & 2))
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 5:
+            if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+            {
+               if (dsp_row != NULL)
+                  png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         default:
+         case 6:
+            if ((png_ptr->row_number & 1) == 0)
+            {
+               png_read_finish_row(png_ptr);
+               return;
+            }
+            break;
+      }
+   }
+#endif
+
+   if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+      png_error(png_ptr, "Invalid attempt to read row data");
+
+   /* Fill the row with IDAT data: */
+   png_ptr->row_buf[0]=255; /* to force error if no data was found */
+   png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1);
+
+   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
+   {
+      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
+         png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
+             png_ptr->prev_row + 1, png_ptr->row_buf[0]);
+      else
+         png_error(png_ptr, "bad adaptive filter value");
+   }
+
+   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
+    * 1.5.6, while the buffer really is this big in current versions of libpng
+    * it may not be in the future, so this was changed just to copy the
+    * interlaced count:
+    */
+   memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+   {
+      /* Intrapixel differencing */
+      png_do_read_intrapixel(&row_info, png_ptr->row_buf + 1);
+   }
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   if (png_ptr->transformations)
+      png_do_read_transformations(png_ptr, &row_info);
+#endif
+
+   /* The transformed pixel depth should match the depth now in row_info. */
+   if (png_ptr->transformed_pixel_depth == 0)
+   {
+      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
+      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
+         png_error(png_ptr, "sequential row overflow");
+   }
+
+   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
+      png_error(png_ptr, "internal sequential row size calculation error");
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   /* Expand interlaced rows to full size */
+   if (png_ptr->interlaced != 0 &&
+      (png_ptr->transformations & PNG_INTERLACE) != 0)
+   {
+      if (png_ptr->pass < 6)
+         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
+             png_ptr->transformations);
+
+      if (dsp_row != NULL)
+         png_combine_row(png_ptr, dsp_row, 1/*display*/);
+
+      if (row != NULL)
+         png_combine_row(png_ptr, row, 0/*row*/);
+   }
+
+   else
+#endif
+   {
+      if (row != NULL)
+         png_combine_row(png_ptr, row, -1/*ignored*/);
+
+      if (dsp_row != NULL)
+         png_combine_row(png_ptr, dsp_row, -1/*ignored*/);
+   }
+   png_read_finish_row(png_ptr);
+
+   if (png_ptr->read_row_fn != NULL)
+      (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read one or more rows of image data.  If the image is interlaced,
+ * and png_set_interlace_handling() has been called, the rows need to
+ * contain the contents of the rows from the previous pass.  If the
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
+ * called, the rows contents must be initialized to the contents of the
+ * screen.
+ *
+ * "row" holds the actual image, and pixels are placed in it
+ * as they arrive.  If the image is displayed after each pass, it will
+ * appear to "sparkle" in.  "display_row" can be used to display a
+ * "chunky" progressive image, with finer detail added as it becomes
+ * available.  If you do not want this "chunky" display, you may pass
+ * NULL for display_row.  If you do not want the sparkle display, and
+ * you have not called png_handle_alpha(), you may pass NULL for rows.
+ * If you have called png_handle_alpha(), and the image has either an
+ * alpha channel or a transparency chunk, you must provide a buffer for
+ * rows.  In this case, you do not have to provide a display_row buffer
+ * also, but you may.  If the image is not interlaced, or if you have
+ * not called png_set_interlace_handling(), the display_row buffer will
+ * be ignored, so pass NULL to it.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+
+void PNGAPI
+png_read_rows(png_structrp png_ptr, png_bytepp row,
+    png_bytepp display_row, png_uint_32 num_rows)
+{
+   png_uint_32 i;
+   png_bytepp rp;
+   png_bytepp dp;
+
+   png_debug(1, "in png_read_rows");
+
+   if (png_ptr == NULL)
+      return;
+
+   rp = row;
+   dp = display_row;
+   if (rp != NULL && dp != NULL)
+      for (i = 0; i < num_rows; i++)
+      {
+         png_bytep rptr = *rp++;
+         png_bytep dptr = *dp++;
+
+         png_read_row(png_ptr, rptr, dptr);
+      }
+
+   else if (rp != NULL)
+      for (i = 0; i < num_rows; i++)
+      {
+         png_bytep rptr = *rp;
+         png_read_row(png_ptr, rptr, NULL);
+         rp++;
+      }
+
+   else if (dp != NULL)
+      for (i = 0; i < num_rows; i++)
+      {
+         png_bytep dptr = *dp;
+         png_read_row(png_ptr, NULL, dptr);
+         dp++;
+      }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the entire image.  If the image has an alpha channel or a tRNS
+ * chunk, and you have called png_handle_alpha()[*], you will need to
+ * initialize the image to the current image that PNG will be overlaying.
+ * We set the num_rows again here, in case it was incorrectly set in
+ * png_read_start_row() by a call to png_read_update_info() or
+ * png_start_read_image() if png_set_interlace_handling() wasn't called
+ * prior to either of these functions like it should have been.  You can
+ * only call this function once.  If you desire to have an image for
+ * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of this version of libpng
+ */
+void PNGAPI
+png_read_image(png_structrp png_ptr, png_bytepp image)
+{
+   png_uint_32 i, image_height;
+   int pass, j;
+   png_bytepp rp;
+
+   png_debug(1, "in png_read_image");
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+   {
+      pass = png_set_interlace_handling(png_ptr);
+      /* And make sure transforms are initialized. */
+      png_start_read_image(png_ptr);
+   }
+   else
+   {
+      if (png_ptr->interlaced != 0 &&
+          (png_ptr->transformations & PNG_INTERLACE) == 0)
+      {
+         /* Caller called png_start_read_image or png_read_update_info without
+          * first turning on the PNG_INTERLACE transform.  We can fix this here,
+          * but the caller should do it!
+          */
+         png_warning(png_ptr, "Interlace handling should be turned on when "
+             "using png_read_image");
+         /* Make sure this is set correctly */
+         png_ptr->num_rows = png_ptr->height;
+      }
+
+      /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in
+       * the above error case.
+       */
+      pass = png_set_interlace_handling(png_ptr);
+   }
+#else
+   if (png_ptr->interlaced)
+      png_error(png_ptr,
+          "Cannot read interlaced image -- interlace handler disabled");
+
+   pass = 1;
+#endif
+
+   image_height=png_ptr->height;
+
+   for (j = 0; j < pass; j++)
+   {
+      rp = image;
+      for (i = 0; i < image_height; i++)
+      {
+         png_read_row(png_ptr, *rp, NULL);
+         rp++;
+      }
+   }
+}
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+/* Read the end of the PNG file.  Will not read past the end of the
+ * file, will verify the end is accurate, and will read any comments
+ * or time information at the end of the file, if info is not NULL.
+ */
+void PNGAPI
+png_read_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep;
+#endif
+
+   png_debug(1, "in png_read_end");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* If png_read_end is called in the middle of reading the rows there may
+    * still be pending IDAT data and an owned zstream.  Deal with this here.
+    */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0)
+#endif
+      png_read_finish_IDAT(png_ptr);
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   /* Report invalid palette index; added at libng-1.5.10 */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+       png_ptr->num_palette_max > png_ptr->num_palette)
+      png_benign_error(png_ptr, "Read palette index exceeding num_palette");
+#endif
+
+   do
+   {
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      png_uint_32 chunk_name = png_ptr->chunk_name;
+
+      if (chunk_name != png_IDAT)
+         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+      if (chunk_name == png_IEND)
+         png_handle_IEND(png_ptr, info_ptr, length);
+
+      else if (chunk_name == png_IHDR)
+         png_handle_IHDR(png_ptr, info_ptr, length);
+
+      else if (info_ptr == NULL)
+         png_crc_finish(png_ptr, length);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
+      {
+         if (chunk_name == png_IDAT)
+         {
+            if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+                || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
+               png_benign_error(png_ptr, ".Too many IDATs found");
+         }
+         png_handle_unknown(png_ptr, info_ptr, length, keep);
+         if (chunk_name == png_PLTE)
+            png_ptr->mode |= PNG_HAVE_PLTE;
+      }
+#endif
+
+      else if (chunk_name == png_IDAT)
+      {
+         /* Zero length IDATs are legal after the last IDAT has been
+          * read, but not after other chunks have been read.  1.6 does not
+          * always read all the deflate data; specifically it cannot be relied
+          * upon to read the Adler32 at the end.  If it doesn't ignore IDAT
+          * chunks which are longer than zero as well:
+          */
+         if ((length > 0 && !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+             || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
+            png_benign_error(png_ptr, "..Too many IDATs found");
+
+         png_crc_finish(png_ptr, length);
+      }
+      else if (chunk_name == png_PLTE)
+         png_handle_PLTE(png_ptr, info_ptr, length);
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+      else if (chunk_name == png_bKGD)
+         png_handle_bKGD(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+      else if (chunk_name == png_cHRM)
+         png_handle_cHRM(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_eXIf_SUPPORTED
+      else if (chunk_name == png_eXIf)
+         png_handle_eXIf(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+      else if (chunk_name == png_gAMA)
+         png_handle_gAMA(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+      else if (chunk_name == png_hIST)
+         png_handle_hIST(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+      else if (chunk_name == png_oFFs)
+         png_handle_oFFs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+      else if (chunk_name == png_pCAL)
+         png_handle_pCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+      else if (chunk_name == png_sCAL)
+         png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+      else if (chunk_name == png_pHYs)
+         png_handle_pHYs(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+      else if (chunk_name == png_sBIT)
+         png_handle_sBIT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+      else if (chunk_name == png_sRGB)
+         png_handle_sRGB(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+      else if (chunk_name == png_iCCP)
+         png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+      else if (chunk_name == png_sPLT)
+         png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+      else if (chunk_name == png_tEXt)
+         png_handle_tEXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+      else if (chunk_name == png_tIME)
+         png_handle_tIME(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+      else if (chunk_name == png_tRNS)
+         png_handle_tRNS(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+      else if (chunk_name == png_zTXt)
+         png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+      else if (chunk_name == png_iTXt)
+         png_handle_iTXt(png_ptr, info_ptr, length);
+#endif
+
+      else
+         png_handle_unknown(png_ptr, info_ptr, length,
+             PNG_HANDLE_CHUNK_AS_DEFAULT);
+   } while ((png_ptr->mode & PNG_HAVE_IEND) == 0);
+}
+#endif /* SEQUENTIAL_READ */
+
+/* Free all memory used in the read struct */
+static void
+png_read_destroy(png_structrp png_ptr)
+{
+   png_debug(1, "in png_read_destroy");
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_destroy_gamma_table(png_ptr);
+#endif
+
+   png_free(png_ptr, png_ptr->big_row_buf);
+   png_ptr->big_row_buf = NULL;
+   png_free(png_ptr, png_ptr->big_prev_row);
+   png_ptr->big_prev_row = NULL;
+   png_free(png_ptr, png_ptr->read_buffer);
+   png_ptr->read_buffer = NULL;
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_free(png_ptr, png_ptr->palette_lookup);
+   png_ptr->palette_lookup = NULL;
+   png_free(png_ptr, png_ptr->quantize_index);
+   png_ptr->quantize_index = NULL;
+#endif
+
+   if ((png_ptr->free_me & PNG_FREE_PLTE) != 0)
+   {
+      png_zfree(png_ptr, png_ptr->palette);
+      png_ptr->palette = NULL;
+   }
+   png_ptr->free_me &= ~PNG_FREE_PLTE;
+
+#if defined(PNG_tRNS_SUPPORTED) || \
+    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   if ((png_ptr->free_me & PNG_FREE_TRNS) != 0)
+   {
+      png_free(png_ptr, png_ptr->trans_alpha);
+      png_ptr->trans_alpha = NULL;
+   }
+   png_ptr->free_me &= ~PNG_FREE_TRNS;
+#endif
+
+   inflateEnd(&png_ptr->zstream);
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_free(png_ptr, png_ptr->save_buffer);
+   png_ptr->save_buffer = NULL;
+#endif
+
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \
+   defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+   png_free(png_ptr, png_ptr->unknown_chunk.data);
+   png_ptr->unknown_chunk.data = NULL;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   png_free(png_ptr, png_ptr->chunk_list);
+   png_ptr->chunk_list = NULL;
+#endif
+
+   /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error
+    * callbacks are still set at this point.  They are required to complete the
+    * destruction of the png_struct itself.
+    */
+}
+
+/* Free all memory used by the read */
+void PNGAPI
+png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
+    png_infopp end_info_ptr_ptr)
+{
+   png_structrp png_ptr = NULL;
+
+   png_debug(1, "in png_destroy_read_struct");
+
+   if (png_ptr_ptr != NULL)
+      png_ptr = *png_ptr_ptr;
+
+   if (png_ptr == NULL)
+      return;
+
+   /* libpng 1.6.0: use the API to destroy info structs to ensure consistent
+    * behavior.  Prior to 1.6.0 libpng did extra 'info' destruction in this API.
+    * The extra was, apparently, unnecessary yet this hides memory leak bugs.
+    */
+   png_destroy_info_struct(png_ptr, end_info_ptr_ptr);
+   png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+   *png_ptr_ptr = NULL;
+   png_read_destroy(png_ptr);
+   png_destroy_png_struct(png_ptr);
+}
+
+void PNGAPI
+png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->read_row_fn = read_row_fn;
+}
+
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_read_png(png_structrp png_ptr, png_inforp info_ptr,
+    int transforms, voidp params)
+{
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   /* png_read_info() gives us all of the information from the
+    * PNG file before the first IDAT (image data chunk).
+    */
+   png_read_info(png_ptr, info_ptr);
+   if (info_ptr->height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
+      png_error(png_ptr, "Image is too high to process with png_read_png()");
+
+   /* -------------- image transformations start here ------------------- */
+   /* libpng 1.6.10: add code to cause a png_app_error if a selected TRANSFORM
+    * is not implemented.  This will only happen in de-configured (non-default)
+    * libpng builds.  The results can be unexpected - png_read_png may return
+    * short or mal-formed rows because the transform is skipped.
+    */
+
+   /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+    */
+   if ((transforms & PNG_TRANSFORM_SCALE_16) != 0)
+      /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+       * did in earlier versions, while "scale_16" is now more accurate.
+       */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+      png_set_scale_16(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SCALE_16 not supported");
+#endif
+
+   /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+    * latter by doing SCALE first.  This is ok and allows apps not to check for
+    * which is supported to get the right answer.
+    */
+   if ((transforms & PNG_TRANSFORM_STRIP_16) != 0)
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+      png_set_strip_16(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_16 not supported");
+#endif
+
+   /* Strip alpha bytes from the input data without combining with
+    * the background (not recommended).
+    */
+   if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0)
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+      png_set_strip_alpha(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_ALPHA not supported");
+#endif
+
+   /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
+    * byte into separate bytes (useful for paletted and grayscale images).
+    */
+   if ((transforms & PNG_TRANSFORM_PACKING) != 0)
+#ifdef PNG_READ_PACK_SUPPORTED
+      png_set_packing(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+   /* Change the order of packed pixels to least significant bit first
+    * (not useful if you are using png_set_packing).
+    */
+   if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+      png_set_packswap(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+   /* Expand paletted colors into true RGB triplets
+    * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+    * Expand paletted or RGB images with transparency to full alpha
+    * channels so the data will be available as RGBA quartets.
+    */
+   if ((transforms & PNG_TRANSFORM_EXPAND) != 0)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+      png_set_expand(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND not supported");
+#endif
+
+   /* We don't handle background color or gamma transformation or quantizing.
+    */
+
+   /* Invert monochrome files to have 0 as white and 1 as black
+    */
+   if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
+#ifdef PNG_READ_INVERT_SUPPORTED
+      png_set_invert_mono(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+   /* If you want to shift the pixel values from the range [0,255] or
+    * [0,65535] to the original [0,7] or [0,31], or whatever range the
+    * colors were originally in:
+    */
+   if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
+#ifdef PNG_READ_SHIFT_SUPPORTED
+      if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+         png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+   /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
+   if ((transforms & PNG_TRANSFORM_BGR) != 0)
+#ifdef PNG_READ_BGR_SUPPORTED
+      png_set_bgr(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+   /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+   if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+      png_set_swap_alpha(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+   /* Swap bytes of 16-bit files to least significant byte first */
+   if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
+#ifdef PNG_READ_SWAP_SUPPORTED
+      png_set_swap(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+/* Added at libpng-1.2.41 */
+   /* Invert the alpha channel from opacity to transparency */
+   if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+      png_set_invert_alpha(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+/* Added at libpng-1.2.41 */
+   /* Expand grayscale image to RGB */
+   if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+      png_set_gray_to_rgb(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_GRAY_TO_RGB not supported");
+#endif
+
+/* Added at libpng-1.5.4 */
+   if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0)
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+      png_set_expand_16(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_EXPAND_16 not supported");
+#endif
+
+   /* We don't handle adding filler bytes */
+
+   /* We use png_read_image and rely on that for interlace handling, but we also
+    * call png_read_update_info therefore must turn on interlace handling now:
+    */
+   (void)png_set_interlace_handling(png_ptr);
+
+   /* Optional call to gamma correct and add the background to the palette
+    * and update info structure.  REQUIRED if you are expecting libpng to
+    * update the palette for you (i.e., you selected such a transform above).
+    */
+   png_read_update_info(png_ptr, info_ptr);
+
+   /* -------------- image transformations end here ------------------- */
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+   if (info_ptr->row_pointers == NULL)
+   {
+      png_uint_32 iptr;
+
+      info_ptr->row_pointers = png_voidcast(png_bytepp, png_malloc(png_ptr,
+          info_ptr->height * (sizeof (png_bytep))));
+
+      for (iptr=0; iptr<info_ptr->height; iptr++)
+         info_ptr->row_pointers[iptr] = NULL;
+
+      info_ptr->free_me |= PNG_FREE_ROWS;
+
+      for (iptr = 0; iptr < info_ptr->height; iptr++)
+         info_ptr->row_pointers[iptr] = png_voidcast(png_bytep,
+             png_malloc(png_ptr, info_ptr->rowbytes));
+   }
+
+   png_read_image(png_ptr, info_ptr->row_pointers);
+   info_ptr->valid |= PNG_INFO_IDAT;
+
+   /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+   png_read_end(png_ptr, info_ptr);
+
+   PNG_UNUSED(params)
+}
+#endif /* INFO_IMAGE */
+#endif /* SEQUENTIAL_READ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* SIMPLIFIED READ
+ *
+ * This code currently relies on the sequential reader, though it could easily
+ * be made to work with the progressive one.
+ */
+/* Arguments to png_image_finish_read: */
+
+/* Encoding of PNG data (used by the color-map code) */
+#  define P_NOTSET  0 /* File encoding not yet known */
+#  define P_sRGB    1 /* 8-bit encoded to sRGB gamma */
+#  define P_LINEAR  2 /* 16-bit linear: not encoded, NOT pre-multiplied! */
+#  define P_FILE    3 /* 8-bit encoded to file gamma, not sRGB or linear */
+#  define P_LINEAR8 4 /* 8-bit linear: only from a file value */
+
+/* Color-map processing: after libpng has run on the PNG image further
+ * processing may be needed to convert the data to color-map indices.
+ */
+#define PNG_CMAP_NONE      0
+#define PNG_CMAP_GA        1 /* Process GA data to a color-map with alpha */
+#define PNG_CMAP_TRANS     2 /* Process GA data to a background index */
+#define PNG_CMAP_RGB       3 /* Process RGB data */
+#define PNG_CMAP_RGB_ALPHA 4 /* Process RGBA data */
+
+/* The following document where the background is for each processing case. */
+#define PNG_CMAP_NONE_BACKGROUND      256
+#define PNG_CMAP_GA_BACKGROUND        231
+#define PNG_CMAP_TRANS_BACKGROUND     254
+#define PNG_CMAP_RGB_BACKGROUND       256
+#define PNG_CMAP_RGB_ALPHA_BACKGROUND 216
+
+typedef struct
+{
+   /* Arguments: */
+   png_imagep image;
+   png_voidp  buffer;
+   png_int_32 row_stride;
+   png_voidp  colormap;
+   png_const_colorp background;
+   /* Local variables: */
+   png_voidp       local_row;
+   png_voidp       first_row;
+   ptrdiff_t       row_bytes;           /* step between rows */
+   int             file_encoding;       /* E_ values above */
+   png_fixed_point gamma_to_linear;     /* For P_FILE, reciprocal of gamma */
+   int             colormap_processing; /* PNG_CMAP_ values above */
+} png_image_read_control;
+
+/* Do all the *safe* initialization - 'safe' means that png_error won't be
+ * called, so setting up the jmp_buf is not required.  This means that anything
+ * called from here must *not* call png_malloc - it has to call png_malloc_warn
+ * instead so that control is returned safely back to this routine.
+ */
+static int
+png_image_read_init(png_imagep image)
+{
+   if (image->opaque == NULL)
+   {
+      png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, image,
+          png_safe_error, png_safe_warning);
+
+      /* And set the rest of the structure to NULL to ensure that the various
+       * fields are consistent.
+       */
+      memset(image, 0, (sizeof *image));
+      image->version = PNG_IMAGE_VERSION;
+
+      if (png_ptr != NULL)
+      {
+         png_infop info_ptr = png_create_info_struct(png_ptr);
+
+         if (info_ptr != NULL)
+         {
+            png_controlp control = png_voidcast(png_controlp,
+                png_malloc_warn(png_ptr, (sizeof *control)));
+
+            if (control != NULL)
+            {
+               memset(control, 0, (sizeof *control));
+
+               control->png_ptr = png_ptr;
+               control->info_ptr = info_ptr;
+               control->for_write = 0;
+
+               image->opaque = control;
+               return 1;
+            }
+
+            /* Error clean up */
+            png_destroy_info_struct(png_ptr, &info_ptr);
+         }
+
+         png_destroy_read_struct(&png_ptr, NULL, NULL);
+      }
+
+      return png_image_error(image, "png_image_read: out of memory");
+   }
+
+   return png_image_error(image, "png_image_read: opaque pointer not NULL");
+}
+
+/* Utility to find the base format of a PNG file from a png_struct. */
+static png_uint_32
+png_image_format(png_structrp png_ptr)
+{
+   png_uint_32 format = 0;
+
+   if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      format |= PNG_FORMAT_FLAG_COLOR;
+
+   if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      format |= PNG_FORMAT_FLAG_ALPHA;
+
+   /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS
+    * sets the png_struct fields; that's all we are interested in here.  The
+    * precise interaction with an app call to png_set_tRNS and PNG file reading
+    * is unclear.
+    */
+   else if (png_ptr->num_trans > 0)
+      format |= PNG_FORMAT_FLAG_ALPHA;
+
+   if (png_ptr->bit_depth == 16)
+      format |= PNG_FORMAT_FLAG_LINEAR;
+
+   if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0)
+      format |= PNG_FORMAT_FLAG_COLORMAP;
+
+   return format;
+}
+
+/* Is the given gamma significantly different from sRGB?  The test is the same
+ * one used in pngrtran.c when deciding whether to do gamma correction.  The
+ * arithmetic optimizes the division by using the fact that the inverse of the
+ * file sRGB gamma is 2.2
+ */
+static int
+png_gamma_not_sRGB(png_fixed_point g)
+{
+   if (g < PNG_FP_1)
+   {
+      /* An uninitialized gamma is assumed to be sRGB for the simplified API. */
+      if (g == 0)
+         return 0;
+
+      return png_gamma_significant((g * 11 + 2)/5 /* i.e. *2.2, rounded */);
+   }
+
+   return 1;
+}
+
+/* Do the main body of a 'png_image_begin_read' function; read the PNG file
+ * header and fill in all the information.  This is executed in a safe context,
+ * unlike the init routine above.
+ */
+static int
+png_image_read_header(png_voidp argument)
+{
+   png_imagep image = png_voidcast(png_imagep, argument);
+   png_structrp png_ptr = image->opaque->png_ptr;
+   png_inforp info_ptr = image->opaque->info_ptr;
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+   png_set_benign_errors(png_ptr, 1/*warn*/);
+#endif
+   png_read_info(png_ptr, info_ptr);
+
+   /* Do this the fast way; just read directly out of png_struct. */
+   image->width = png_ptr->width;
+   image->height = png_ptr->height;
+
+   {
+      png_uint_32 format = png_image_format(png_ptr);
+
+      image->format = format;
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+      /* Does the colorspace match sRGB?  If there is no color endpoint
+       * (colorant) information assume yes, otherwise require the
+       * 'ENDPOINTS_MATCHP_sRGB' colorspace flag to have been set.  If the
+       * colorspace has been determined to be invalid ignore it.
+       */
+      if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags
+         & (PNG_COLORSPACE_HAVE_ENDPOINTS|PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB|
+            PNG_COLORSPACE_INVALID)) == PNG_COLORSPACE_HAVE_ENDPOINTS))
+         image->flags |= PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB;
+#endif
+   }
+
+   /* We need the maximum number of entries regardless of the format the
+    * application sets here.
+    */
+   {
+      png_uint_32 cmap_entries;
+
+      switch (png_ptr->color_type)
+      {
+         case PNG_COLOR_TYPE_GRAY:
+            cmap_entries = 1U << png_ptr->bit_depth;
+            break;
+
+         case PNG_COLOR_TYPE_PALETTE:
+            cmap_entries = (png_uint_32)png_ptr->num_palette;
+            break;
+
+         default:
+            cmap_entries = 256;
+            break;
+      }
+
+      if (cmap_entries > 256)
+         cmap_entries = 256;
+
+      image->colormap_entries = cmap_entries;
+   }
+
+   return 1;
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+int PNGAPI
+png_image_begin_read_from_stdio(png_imagep image, FILE* file)
+{
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      if (file != NULL)
+      {
+         if (png_image_read_init(image) != 0)
+         {
+            /* This is slightly evil, but png_init_io doesn't do anything other
+             * than this and we haven't changed the standard IO functions so
+             * this saves a 'safe' function.
+             */
+            image->opaque->png_ptr->io_ptr = file;
+            return png_safe_execute(image, png_image_read_header, image);
+         }
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_begin_read_from_stdio: invalid argument");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_begin_read_from_stdio: incorrect PNG_IMAGE_VERSION");
+
+   return 0;
+}
+
+int PNGAPI
+png_image_begin_read_from_file(png_imagep image, const char *file_name)
+{
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      if (file_name != NULL)
+      {
+         FILE *fp = fopen(file_name, "rb");
+
+         if (fp != NULL)
+         {
+            if (png_image_read_init(image) != 0)
+            {
+               image->opaque->png_ptr->io_ptr = fp;
+               image->opaque->owned_file = 1;
+               return png_safe_execute(image, png_image_read_header, image);
+            }
+
+            /* Clean up: just the opened file. */
+            (void)fclose(fp);
+         }
+
+         else
+            return png_image_error(image, strerror(errno));
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_begin_read_from_file: invalid argument");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_begin_read_from_file: incorrect PNG_IMAGE_VERSION");
+
+   return 0;
+}
+#endif /* STDIO */
+
+static void PNGCBAPI
+png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need)
+{
+   if (png_ptr != NULL)
+   {
+      png_imagep image = png_voidcast(png_imagep, png_ptr->io_ptr);
+      if (image != NULL)
+      {
+         png_controlp cp = image->opaque;
+         if (cp != NULL)
+         {
+            png_const_bytep memory = cp->memory;
+            png_size_t size = cp->size;
+
+            if (memory != NULL && size >= need)
+            {
+               memcpy(out, memory, need);
+               cp->memory = memory + need;
+               cp->size = size - need;
+               return;
+            }
+
+            png_error(png_ptr, "read beyond end of data");
+         }
+      }
+
+      png_error(png_ptr, "invalid memory read");
+   }
+}
+
+int PNGAPI png_image_begin_read_from_memory(png_imagep image,
+    png_const_voidp memory, png_size_t size)
+{
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      if (memory != NULL && size > 0)
+      {
+         if (png_image_read_init(image) != 0)
+         {
+            /* Now set the IO functions to read from the memory buffer and
+             * store it into io_ptr.  Again do this in-place to avoid calling a
+             * libpng function that requires error handling.
+             */
+            image->opaque->memory = png_voidcast(png_const_bytep, memory);
+            image->opaque->size = size;
+            image->opaque->png_ptr->io_ptr = image;
+            image->opaque->png_ptr->read_data_fn = png_image_memory_read;
+
+            return png_safe_execute(image, png_image_read_header, image);
+         }
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_begin_read_from_memory: invalid argument");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_begin_read_from_memory: incorrect PNG_IMAGE_VERSION");
+
+   return 0;
+}
+
+/* Utility function to skip chunks that are not used by the simplified image
+ * read functions and an appropriate macro to call it.
+ */
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static void
+png_image_skip_unused_chunks(png_structrp png_ptr)
+{
+   /* Prepare the reader to ignore all recognized chunks whose data will not
+    * be used, i.e., all chunks recognized by libpng except for those
+    * involved in basic image reading:
+    *
+    *    IHDR, PLTE, IDAT, IEND
+    *
+    * Or image data handling:
+    *
+    *    tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT.
+    *
+    * This provides a small performance improvement and eliminates any
+    * potential vulnerability to security problems in the unused chunks.
+    *
+    * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored
+    * too.  This allows the simplified API to be compiled without iCCP support,
+    * however if the support is there the chunk is still checked to detect
+    * errors (which are unfortunately quite common.)
+    */
+   {
+         static PNG_CONST png_byte chunks_to_process[] = {
+            98,  75,  71,  68, '\0',  /* bKGD */
+            99,  72,  82,  77, '\0',  /* cHRM */
+           103,  65,  77,  65, '\0',  /* gAMA */
+#        ifdef PNG_READ_iCCP_SUPPORTED
+           105,  67,  67,  80, '\0',  /* iCCP */
+#        endif
+           115,  66,  73,  84, '\0',  /* sBIT */
+           115,  82,  71,  66, '\0',  /* sRGB */
+           };
+
+       /* Ignore unknown chunks and all other chunks except for the
+        * IHDR, PLTE, tRNS, IDAT, and IEND chunks.
+        */
+       png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_NEVER,
+           NULL, -1);
+
+       /* But do not ignore image data handling chunks */
+       png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
+           chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5);
+   }
+}
+
+#  define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
+#else
+#  define PNG_SKIP_CHUNKS(p) ((void)0)
+#endif /* HANDLE_AS_UNKNOWN */
+
+/* The following macro gives the exact rounded answer for all values in the
+ * range 0..255 (it actually divides by 51.2, but the rounding still generates
+ * the correct numbers 0..5
+ */
+#define PNG_DIV51(v8) (((v8) * 5 + 130) >> 8)
+
+/* Utility functions to make particular color-maps */
+static void
+set_file_encoding(png_image_read_control *display)
+{
+   png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma;
+   if (png_gamma_significant(g) != 0)
+   {
+      if (png_gamma_not_sRGB(g) != 0)
+      {
+         display->file_encoding = P_FILE;
+         display->gamma_to_linear = png_reciprocal(g);
+      }
+
+      else
+         display->file_encoding = P_sRGB;
+   }
+
+   else
+      display->file_encoding = P_LINEAR8;
+}
+
+static unsigned int
+decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
+{
+   if (encoding == P_FILE) /* double check */
+      encoding = display->file_encoding;
+
+   if (encoding == P_NOTSET) /* must be the file encoding */
+   {
+      set_file_encoding(display);
+      encoding = display->file_encoding;
+   }
+
+   switch (encoding)
+   {
+      case P_FILE:
+         value = png_gamma_16bit_correct(value*257, display->gamma_to_linear);
+         break;
+
+      case P_sRGB:
+         value = png_sRGB_table[value];
+         break;
+
+      case P_LINEAR:
+         break;
+
+      case P_LINEAR8:
+         value *= 257;
+         break;
+
+#ifdef __GNUC__
+      default:
+         png_error(display->image->opaque->png_ptr,
+             "unexpected encoding (internal error)");
+#endif
+   }
+
+   return value;
+}
+
+static png_uint_32
+png_colormap_compose(png_image_read_control *display,
+    png_uint_32 foreground, int foreground_encoding, png_uint_32 alpha,
+    png_uint_32 background, int encoding)
+{
+   /* The file value is composed on the background, the background has the given
+    * encoding and so does the result, the file is encoded with P_FILE and the
+    * file and alpha are 8-bit values.  The (output) encoding will always be
+    * P_LINEAR or P_sRGB.
+    */
+   png_uint_32 f = decode_gamma(display, foreground, foreground_encoding);
+   png_uint_32 b = decode_gamma(display, background, encoding);
+
+   /* The alpha is always an 8-bit value (it comes from the palette), the value
+    * scaled by 255 is what PNG_sRGB_FROM_LINEAR requires.
+    */
+   f = f * alpha + b * (255-alpha);
+
+   if (encoding == P_LINEAR)
+   {
+      /* Scale to 65535; divide by 255, approximately (in fact this is extremely
+       * accurate, it divides by 255.00000005937181414556, with no overflow.)
+       */
+      f *= 257; /* Now scaled by 65535 */
+      f += f >> 16;
+      f = (f+32768) >> 16;
+   }
+
+   else /* P_sRGB */
+      f = PNG_sRGB_FROM_LINEAR(f);
+
+   return f;
+}
+
+/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must
+ * be 8-bit.
+ */
+static void
+png_create_colormap_entry(png_image_read_control *display,
+    png_uint_32 ip, png_uint_32 red, png_uint_32 green, png_uint_32 blue,
+    png_uint_32 alpha, int encoding)
+{
+   png_imagep image = display->image;
+   const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
+       P_LINEAR : P_sRGB;
+   const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
+       (red != green || green != blue);
+
+   if (ip > 255)
+      png_error(image->opaque->png_ptr, "color-map index out of range");
+
+   /* Update the cache with whether the file gamma is significantly different
+    * from sRGB.
+    */
+   if (encoding == P_FILE)
+   {
+      if (display->file_encoding == P_NOTSET)
+         set_file_encoding(display);
+
+      /* Note that the cached value may be P_FILE too, but if it is then the
+       * gamma_to_linear member has been set.
+       */
+      encoding = display->file_encoding;
+   }
+
+   if (encoding == P_FILE)
+   {
+      png_fixed_point g = display->gamma_to_linear;
+
+      red = png_gamma_16bit_correct(red*257, g);
+      green = png_gamma_16bit_correct(green*257, g);
+      blue = png_gamma_16bit_correct(blue*257, g);
+
+      if (convert_to_Y != 0 || output_encoding == P_LINEAR)
+      {
+         alpha *= 257;
+         encoding = P_LINEAR;
+      }
+
+      else
+      {
+         red = PNG_sRGB_FROM_LINEAR(red * 255);
+         green = PNG_sRGB_FROM_LINEAR(green * 255);
+         blue = PNG_sRGB_FROM_LINEAR(blue * 255);
+         encoding = P_sRGB;
+      }
+   }
+
+   else if (encoding == P_LINEAR8)
+   {
+      /* This encoding occurs quite frequently in test cases because PngSuite
+       * includes a gAMA 1.0 chunk with most images.
+       */
+      red *= 257;
+      green *= 257;
+      blue *= 257;
+      alpha *= 257;
+      encoding = P_LINEAR;
+   }
+
+   else if (encoding == P_sRGB &&
+       (convert_to_Y  != 0 || output_encoding == P_LINEAR))
+   {
+      /* The values are 8-bit sRGB values, but must be converted to 16-bit
+       * linear.
+       */
+      red = png_sRGB_table[red];
+      green = png_sRGB_table[green];
+      blue = png_sRGB_table[blue];
+      alpha *= 257;
+      encoding = P_LINEAR;
+   }
+
+   /* This is set if the color isn't gray but the output is. */
+   if (encoding == P_LINEAR)
+   {
+      if (convert_to_Y != 0)
+      {
+         /* NOTE: these values are copied from png_do_rgb_to_gray */
+         png_uint_32 y = (png_uint_32)6968 * red  + (png_uint_32)23434 * green +
+            (png_uint_32)2366 * blue;
+
+         if (output_encoding == P_LINEAR)
+            y = (y + 16384) >> 15;
+
+         else
+         {
+            /* y is scaled by 32768, we need it scaled by 255: */
+            y = (y + 128) >> 8;
+            y *= 255;
+            y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
+            alpha = PNG_DIV257(alpha);
+            encoding = P_sRGB;
+         }
+
+         blue = red = green = y;
+      }
+
+      else if (output_encoding == P_sRGB)
+      {
+         red = PNG_sRGB_FROM_LINEAR(red * 255);
+         green = PNG_sRGB_FROM_LINEAR(green * 255);
+         blue = PNG_sRGB_FROM_LINEAR(blue * 255);
+         alpha = PNG_DIV257(alpha);
+         encoding = P_sRGB;
+      }
+   }
+
+   if (encoding != output_encoding)
+      png_error(image->opaque->png_ptr, "bad encoding (internal error)");
+
+   /* Store the value. */
+   {
+#     ifdef PNG_FORMAT_AFIRST_SUPPORTED
+         const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+            (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
+#     else
+#        define afirst 0
+#     endif
+#     ifdef PNG_FORMAT_BGR_SUPPORTED
+         const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
+#     else
+#        define bgr 0
+#     endif
+
+      if (output_encoding == P_LINEAR)
+      {
+         png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap);
+
+         entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
+
+         /* The linear 16-bit values must be pre-multiplied by the alpha channel
+          * value, if less than 65535 (this is, effectively, composite on black
+          * if the alpha channel is removed.)
+          */
+         switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
+         {
+            case 4:
+               entry[afirst ? 0 : 3] = (png_uint_16)alpha;
+               /* FALLTHROUGH */
+
+            case 3:
+               if (alpha < 65535)
+               {
+                  if (alpha > 0)
+                  {
+                     blue = (blue * alpha + 32767U)/65535U;
+                     green = (green * alpha + 32767U)/65535U;
+                     red = (red * alpha + 32767U)/65535U;
+                  }
+
+                  else
+                     red = green = blue = 0;
+               }
+               entry[afirst + (2 ^ bgr)] = (png_uint_16)blue;
+               entry[afirst + 1] = (png_uint_16)green;
+               entry[afirst + bgr] = (png_uint_16)red;
+               break;
+
+            case 2:
+               entry[1 ^ afirst] = (png_uint_16)alpha;
+               /* FALLTHROUGH */
+
+            case 1:
+               if (alpha < 65535)
+               {
+                  if (alpha > 0)
+                     green = (green * alpha + 32767U)/65535U;
+
+                  else
+                     green = 0;
+               }
+               entry[afirst] = (png_uint_16)green;
+               break;
+
+            default:
+               break;
+         }
+      }
+
+      else /* output encoding is P_sRGB */
+      {
+         png_bytep entry = png_voidcast(png_bytep, display->colormap);
+
+         entry += ip * PNG_IMAGE_SAMPLE_CHANNELS(image->format);
+
+         switch (PNG_IMAGE_SAMPLE_CHANNELS(image->format))
+         {
+            case 4:
+               entry[afirst ? 0 : 3] = (png_byte)alpha;
+               /* FALLTHROUGH */
+            case 3:
+               entry[afirst + (2 ^ bgr)] = (png_byte)blue;
+               entry[afirst + 1] = (png_byte)green;
+               entry[afirst + bgr] = (png_byte)red;
+               break;
+
+            case 2:
+               entry[1 ^ afirst] = (png_byte)alpha;
+               /* FALLTHROUGH */
+            case 1:
+               entry[afirst] = (png_byte)green;
+               break;
+
+            default:
+               break;
+         }
+      }
+
+#     ifdef afirst
+#        undef afirst
+#     endif
+#     ifdef bgr
+#        undef bgr
+#     endif
+   }
+}
+
+static int
+make_gray_file_colormap(png_image_read_control *display)
+{
+   unsigned int i;
+
+   for (i=0; i<256; ++i)
+      png_create_colormap_entry(display, i, i, i, i, 255, P_FILE);
+
+   return (int)i;
+}
+
+static int
+make_gray_colormap(png_image_read_control *display)
+{
+   unsigned int i;
+
+   for (i=0; i<256; ++i)
+      png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB);
+
+   return (int)i;
+}
+#define PNG_GRAY_COLORMAP_ENTRIES 256
+
+static int
+make_ga_colormap(png_image_read_control *display)
+{
+   unsigned int i, a;
+
+   /* Alpha is retained, the output will be a color-map with entries
+    * selected by six levels of alpha.  One transparent entry, 6 gray
+    * levels for all the intermediate alpha values, leaving 230 entries
+    * for the opaque grays.  The color-map entries are the six values
+    * [0..5]*51, the GA processing uses PNG_DIV51(value) to find the
+    * relevant entry.
+    *
+    * if (alpha > 229) // opaque
+    * {
+    *    // The 231 entries are selected to make the math below work:
+    *    base = 0;
+    *    entry = (231 * gray + 128) >> 8;
+    * }
+    * else if (alpha < 26) // transparent
+    * {
+    *    base = 231;
+    *    entry = 0;
+    * }
+    * else // partially opaque
+    * {
+    *    base = 226 + 6 * PNG_DIV51(alpha);
+    *    entry = PNG_DIV51(gray);
+    * }
+    */
+   i = 0;
+   while (i < 231)
+   {
+      unsigned int gray = (i * 256 + 115) / 231;
+      png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB);
+   }
+
+   /* 255 is used here for the component values for consistency with the code
+    * that undoes premultiplication in pngwrite.c.
+    */
+   png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB);
+
+   for (a=1; a<5; ++a)
+   {
+      unsigned int g;
+
+      for (g=0; g<6; ++g)
+         png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
+             P_sRGB);
+   }
+
+   return (int)i;
+}
+
+#define PNG_GA_COLORMAP_ENTRIES 256
+
+static int
+make_rgb_colormap(png_image_read_control *display)
+{
+   unsigned int i, r;
+
+   /* Build a 6x6x6 opaque RGB cube */
+   for (i=r=0; r<6; ++r)
+   {
+      unsigned int g;
+
+      for (g=0; g<6; ++g)
+      {
+         unsigned int b;
+
+         for (b=0; b<6; ++b)
+            png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
+                P_sRGB);
+      }
+   }
+
+   return (int)i;
+}
+
+#define PNG_RGB_COLORMAP_ENTRIES 216
+
+/* Return a palette index to the above palette given three 8-bit sRGB values. */
+#define PNG_RGB_INDEX(r,g,b) \
+   ((png_byte)(6 * (6 * PNG_DIV51(r) + PNG_DIV51(g)) + PNG_DIV51(b)))
+
+static int
+png_image_read_colormap(png_voidp argument)
+{
+   png_image_read_control *display =
+      png_voidcast(png_image_read_control*, argument);
+   const png_imagep image = display->image;
+
+   const png_structrp png_ptr = image->opaque->png_ptr;
+   const png_uint_32 output_format = image->format;
+   const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
+      P_LINEAR : P_sRGB;
+
+   unsigned int cmap_entries;
+   unsigned int output_processing;        /* Output processing option */
+   unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */
+
+   /* Background information; the background color and the index of this color
+    * in the color-map if it exists (else 256).
+    */
+   unsigned int background_index = 256;
+   png_uint_32 back_r, back_g, back_b;
+
+   /* Flags to accumulate things that need to be done to the input. */
+   int expand_tRNS = 0;
+
+   /* Exclude the NYI feature of compositing onto a color-mapped buffer; it is
+    * very difficult to do, the results look awful, and it is difficult to see
+    * what possible use it is because the application can't control the
+    * color-map.
+    */
+   if (((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0 ||
+         png_ptr->num_trans > 0) /* alpha in input */ &&
+      ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */)
+   {
+      if (output_encoding == P_LINEAR) /* compose on black */
+         back_b = back_g = back_r = 0;
+
+      else if (display->background == NULL /* no way to remove it */)
+         png_error(png_ptr,
+             "background color must be supplied to remove alpha/transparency");
+
+      /* Get a copy of the background color (this avoids repeating the checks
+       * below.)  The encoding is 8-bit sRGB or 16-bit linear, depending on the
+       * output format.
+       */
+      else
+      {
+         back_g = display->background->green;
+         if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0)
+         {
+            back_r = display->background->red;
+            back_b = display->background->blue;
+         }
+         else
+            back_b = back_r = back_g;
+      }
+   }
+
+   else if (output_encoding == P_LINEAR)
+      back_b = back_r = back_g = 65535;
+
+   else
+      back_b = back_r = back_g = 255;
+
+   /* Default the input file gamma if required - this is necessary because
+    * libpng assumes that if no gamma information is present the data is in the
+    * output format, but the simplified API deduces the gamma from the input
+    * format.
+    */
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) == 0)
+   {
+      /* Do this directly, not using the png_colorspace functions, to ensure
+       * that it happens even if the colorspace is invalid (though probably if
+       * it is the setting will be ignored)  Note that the same thing can be
+       * achieved at the application interface with png_set_gAMA.
+       */
+      if (png_ptr->bit_depth == 16 &&
+         (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+         png_ptr->colorspace.gamma = PNG_GAMMA_LINEAR;
+
+      else
+         png_ptr->colorspace.gamma = PNG_GAMMA_sRGB_INVERSE;
+
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+   }
+
+   /* Decide what to do based on the PNG color type of the input data.  The
+    * utility function png_create_colormap_entry deals with most aspects of the
+    * output transformations; this code works out how to produce bytes of
+    * color-map entries from the original format.
+    */
+   switch (png_ptr->color_type)
+   {
+      case PNG_COLOR_TYPE_GRAY:
+         if (png_ptr->bit_depth <= 8)
+         {
+            /* There at most 256 colors in the output, regardless of
+             * transparency.
+             */
+            unsigned int step, i, val, trans = 256/*ignore*/, back_alpha = 0;
+
+            cmap_entries = 1U << png_ptr->bit_depth;
+            if (cmap_entries > image->colormap_entries)
+               png_error(png_ptr, "gray[8] color-map: too few entries");
+
+            step = 255 / (cmap_entries - 1);
+            output_processing = PNG_CMAP_NONE;
+
+            /* If there is a tRNS chunk then this either selects a transparent
+             * value or, if the output has no alpha, the background color.
+             */
+            if (png_ptr->num_trans > 0)
+            {
+               trans = png_ptr->trans_color.gray;
+
+               if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0)
+                  back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+            }
+
+            /* png_create_colormap_entry just takes an RGBA and writes the
+             * corresponding color-map entry using the format from 'image',
+             * including the required conversion to sRGB or linear as
+             * appropriate.  The input values are always either sRGB (if the
+             * gamma correction flag is 0) or 0..255 scaled file encoded values
+             * (if the function must gamma correct them).
+             */
+            for (i=val=0; i<cmap_entries; ++i, val += step)
+            {
+               /* 'i' is a file value.  While this will result in duplicated
+                * entries for 8-bit non-sRGB encoded files it is necessary to
+                * have non-gamma corrected values to do tRNS handling.
+                */
+               if (i != trans)
+                  png_create_colormap_entry(display, i, val, val, val, 255,
+                      P_FILE/*8-bit with file gamma*/);
+
+               /* Else this entry is transparent.  The colors don't matter if
+                * there is an alpha channel (back_alpha == 0), but it does no
+                * harm to pass them in; the values are not set above so this
+                * passes in white.
+                *
+                * NOTE: this preserves the full precision of the application
+                * supplied background color when it is used.
+                */
+               else
+                  png_create_colormap_entry(display, i, back_r, back_g, back_b,
+                      back_alpha, output_encoding);
+            }
+
+            /* We need libpng to preserve the original encoding. */
+            data_encoding = P_FILE;
+
+            /* The rows from libpng, while technically gray values, are now also
+             * color-map indices; however, they may need to be expanded to 1
+             * byte per pixel.  This is what png_set_packing does (i.e., it
+             * unpacks the bit values into bytes.)
+             */
+            if (png_ptr->bit_depth < 8)
+               png_set_packing(png_ptr);
+         }
+
+         else /* bit depth is 16 */
+         {
+            /* The 16-bit input values can be converted directly to 8-bit gamma
+             * encoded values; however, if a tRNS chunk is present 257 color-map
+             * entries are required.  This means that the extra entry requires
+             * special processing; add an alpha channel, sacrifice gray level
+             * 254 and convert transparent (alpha==0) entries to that.
+             *
+             * Use libpng to chop the data to 8 bits.  Convert it to sRGB at the
+             * same time to minimize quality loss.  If a tRNS chunk is present
+             * this means libpng must handle it too; otherwise it is impossible
+             * to do the exact match on the 16-bit value.
+             *
+             * If the output has no alpha channel *and* the background color is
+             * gray then it is possible to let libpng handle the substitution by
+             * ensuring that the corresponding gray level matches the background
+             * color exactly.
+             */
+            data_encoding = P_sRGB;
+
+            if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+               png_error(png_ptr, "gray[16] color-map: too few entries");
+
+            cmap_entries = (unsigned int)make_gray_colormap(display);
+
+            if (png_ptr->num_trans > 0)
+            {
+               unsigned int back_alpha;
+
+               if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+                  back_alpha = 0;
+
+               else
+               {
+                  if (back_r == back_g && back_g == back_b)
+                  {
+                     /* Background is gray; no special processing will be
+                      * required.
+                      */
+                     png_color_16 c;
+                     png_uint_32 gray = back_g;
+
+                     if (output_encoding == P_LINEAR)
+                     {
+                        gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+                        /* And make sure the corresponding palette entry
+                         * matches.
+                         */
+                        png_create_colormap_entry(display, gray, back_g, back_g,
+                            back_g, 65535, P_LINEAR);
+                     }
+
+                     /* The background passed to libpng, however, must be the
+                      * sRGB value.
+                      */
+                     c.index = 0; /*unused*/
+                     c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+                     /* NOTE: does this work without expanding tRNS to alpha?
+                      * It should be the color->gray case below apparently
+                      * doesn't.
+                      */
+                     png_set_background_fixed(png_ptr, &c,
+                         PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                         0/*gamma: not used*/);
+
+                     output_processing = PNG_CMAP_NONE;
+                     break;
+                  }
+#ifdef __COVERITY__
+                 /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+                  * here.
+                  */
+                  back_alpha = 255;
+#else
+                  back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+#endif
+               }
+
+               /* output_processing means that the libpng-processed row will be
+                * 8-bit GA and it has to be processing to single byte color-map
+                * values.  Entry 254 is replaced by either a completely
+                * transparent entry or by the background color at full
+                * precision (and the background color is not a simple gray
+                * level in this case.)
+                */
+               expand_tRNS = 1;
+               output_processing = PNG_CMAP_TRANS;
+               background_index = 254;
+
+               /* And set (overwrite) color-map entry 254 to the actual
+                * background color at full precision.
+                */
+               png_create_colormap_entry(display, 254, back_r, back_g, back_b,
+                   back_alpha, output_encoding);
+            }
+
+            else
+               output_processing = PNG_CMAP_NONE;
+         }
+         break;
+
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         /* 8-bit or 16-bit PNG with two channels - gray and alpha.  A minimum
+          * of 65536 combinations.  If, however, the alpha channel is to be
+          * removed there are only 256 possibilities if the background is gray.
+          * (Otherwise there is a subset of the 65536 possibilities defined by
+          * the triangle between black, white and the background color.)
+          *
+          * Reduce 16-bit files to 8-bit and sRGB encode the result.  No need to
+          * worry about tRNS matching - tRNS is ignored if there is an alpha
+          * channel.
+          */
+         data_encoding = P_sRGB;
+
+         if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+         {
+            if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+               png_error(png_ptr, "gray+alpha color-map: too few entries");
+
+            cmap_entries = (unsigned int)make_ga_colormap(display);
+
+            background_index = PNG_CMAP_GA_BACKGROUND;
+            output_processing = PNG_CMAP_GA;
+         }
+
+         else /* alpha is removed */
+         {
+            /* Alpha must be removed as the PNG data is processed when the
+             * background is a color because the G and A channels are
+             * independent and the vector addition (non-parallel vectors) is a
+             * 2-D problem.
+             *
+             * This can be reduced to the same algorithm as above by making a
+             * colormap containing gray levels (for the opaque grays), a
+             * background entry (for a transparent pixel) and a set of four six
+             * level color values, one set for each intermediate alpha value.
+             * See the comments in make_ga_colormap for how this works in the
+             * per-pixel processing.
+             *
+             * If the background is gray, however, we only need a 256 entry gray
+             * level color map.  It is sufficient to make the entry generated
+             * for the background color be exactly the color specified.
+             */
+            if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0 ||
+               (back_r == back_g && back_g == back_b))
+            {
+               /* Background is gray; no special processing will be required. */
+               png_color_16 c;
+               png_uint_32 gray = back_g;
+
+               if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+                  png_error(png_ptr, "gray-alpha color-map: too few entries");
+
+               cmap_entries = (unsigned int)make_gray_colormap(display);
+
+               if (output_encoding == P_LINEAR)
+               {
+                  gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+                  /* And make sure the corresponding palette entry matches. */
+                  png_create_colormap_entry(display, gray, back_g, back_g,
+                      back_g, 65535, P_LINEAR);
+               }
+
+               /* The background passed to libpng, however, must be the sRGB
+                * value.
+                */
+               c.index = 0; /*unused*/
+               c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+               png_set_background_fixed(png_ptr, &c,
+                   PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                   0/*gamma: not used*/);
+
+               output_processing = PNG_CMAP_NONE;
+            }
+
+            else
+            {
+               png_uint_32 i, a;
+
+               /* This is the same as png_make_ga_colormap, above, except that
+                * the entries are all opaque.
+                */
+               if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+                  png_error(png_ptr, "ga-alpha color-map: too few entries");
+
+               i = 0;
+               while (i < 231)
+               {
+                  png_uint_32 gray = (i * 256 + 115) / 231;
+                  png_create_colormap_entry(display, i++, gray, gray, gray,
+                      255, P_sRGB);
+               }
+
+               /* NOTE: this preserves the full precision of the application
+                * background color.
+                */
+               background_index = i;
+               png_create_colormap_entry(display, i++, back_r, back_g, back_b,
+#ifdef __COVERITY__
+                   /* Coverity claims that output_encoding
+                    * cannot be 2 (P_LINEAR) here.
+                    */ 255U,
+#else
+                    output_encoding == P_LINEAR ? 65535U : 255U,
+#endif
+                    output_encoding);
+
+               /* For non-opaque input composite on the sRGB background - this
+                * requires inverting the encoding for each component.  The input
+                * is still converted to the sRGB encoding because this is a
+                * reasonable approximate to the logarithmic curve of human
+                * visual sensitivity, at least over the narrow range which PNG
+                * represents.  Consequently 'G' is always sRGB encoded, while
+                * 'A' is linear.  We need the linear background colors.
+                */
+               if (output_encoding == P_sRGB) /* else already linear */
+               {
+                  /* This may produce a value not exactly matching the
+                   * background, but that's ok because these numbers are only
+                   * used when alpha != 0
+                   */
+                  back_r = png_sRGB_table[back_r];
+                  back_g = png_sRGB_table[back_g];
+                  back_b = png_sRGB_table[back_b];
+               }
+
+               for (a=1; a<5; ++a)
+               {
+                  unsigned int g;
+
+                  /* PNG_sRGB_FROM_LINEAR expects a 16-bit linear value scaled
+                   * by an 8-bit alpha value (0..255).
+                   */
+                  png_uint_32 alpha = 51 * a;
+                  png_uint_32 back_rx = (255-alpha) * back_r;
+                  png_uint_32 back_gx = (255-alpha) * back_g;
+                  png_uint_32 back_bx = (255-alpha) * back_b;
+
+                  for (g=0; g<6; ++g)
+                  {
+                     png_uint_32 gray = png_sRGB_table[g*51] * alpha;
+
+                     png_create_colormap_entry(display, i++,
+                         PNG_sRGB_FROM_LINEAR(gray + back_rx),
+                         PNG_sRGB_FROM_LINEAR(gray + back_gx),
+                         PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB);
+                  }
+               }
+
+               cmap_entries = i;
+               output_processing = PNG_CMAP_GA;
+            }
+         }
+         break;
+
+      case PNG_COLOR_TYPE_RGB:
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+         /* Exclude the case where the output is gray; we can always handle this
+          * with the cases above.
+          */
+         if ((output_format & PNG_FORMAT_FLAG_COLOR) == 0)
+         {
+            /* The color-map will be grayscale, so we may as well convert the
+             * input RGB values to a simple grayscale and use the grayscale
+             * code above.
+             *
+             * NOTE: calling this apparently damages the recognition of the
+             * transparent color in background color handling; call
+             * png_set_tRNS_to_alpha before png_set_background_fixed.
+             */
+            png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
+                -1);
+            data_encoding = P_sRGB;
+
+            /* The output will now be one or two 8-bit gray or gray+alpha
+             * channels.  The more complex case arises when the input has alpha.
+             */
+            if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+               png_ptr->num_trans > 0) &&
+               (output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+            {
+               /* Both input and output have an alpha channel, so no background
+                * processing is required; just map the GA bytes to the right
+                * color-map entry.
+                */
+               expand_tRNS = 1;
+
+               if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
+                  png_error(png_ptr, "rgb[ga] color-map: too few entries");
+
+               cmap_entries = (unsigned int)make_ga_colormap(display);
+               background_index = PNG_CMAP_GA_BACKGROUND;
+               output_processing = PNG_CMAP_GA;
+            }
+
+            else
+            {
+               /* Either the input or the output has no alpha channel, so there
+                * will be no non-opaque pixels in the color-map; it will just be
+                * grayscale.
+                */
+               if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
+                  png_error(png_ptr, "rgb[gray] color-map: too few entries");
+
+               /* Ideally this code would use libpng to do the gamma correction,
+                * but if an input alpha channel is to be removed we will hit the
+                * libpng bug in gamma+compose+rgb-to-gray (the double gamma
+                * correction bug).  Fix this by dropping the gamma correction in
+                * this case and doing it in the palette; this will result in
+                * duplicate palette entries, but that's better than the
+                * alternative of double gamma correction.
+                */
+               if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+                  png_ptr->num_trans > 0) &&
+                  png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0)
+               {
+                  cmap_entries = (unsigned int)make_gray_file_colormap(display);
+                  data_encoding = P_FILE;
+               }
+
+               else
+                  cmap_entries = (unsigned int)make_gray_colormap(display);
+
+               /* But if the input has alpha or transparency it must be removed
+                */
+               if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+                  png_ptr->num_trans > 0)
+               {
+                  png_color_16 c;
+                  png_uint_32 gray = back_g;
+
+                  /* We need to ensure that the application background exists in
+                   * the colormap and that completely transparent pixels map to
+                   * it.  Achieve this simply by ensuring that the entry
+                   * selected for the background really is the background color.
+                   */
+                  if (data_encoding == P_FILE) /* from the fixup above */
+                  {
+                     /* The app supplied a gray which is in output_encoding, we
+                      * need to convert it to a value of the input (P_FILE)
+                      * encoding then set this palette entry to the required
+                      * output encoding.
+                      */
+                     if (output_encoding == P_sRGB)
+                        gray = png_sRGB_table[gray]; /* now P_LINEAR */
+
+                     gray = PNG_DIV257(png_gamma_16bit_correct(gray,
+                         png_ptr->colorspace.gamma)); /* now P_FILE */
+
+                     /* And make sure the corresponding palette entry contains
+                      * exactly the required sRGB value.
+                      */
+                     png_create_colormap_entry(display, gray, back_g, back_g,
+                         back_g, 0/*unused*/, output_encoding);
+                  }
+
+                  else if (output_encoding == P_LINEAR)
+                  {
+                     gray = PNG_sRGB_FROM_LINEAR(gray * 255);
+
+                     /* And make sure the corresponding palette entry matches.
+                      */
+                     png_create_colormap_entry(display, gray, back_g, back_g,
+                        back_g, 0/*unused*/, P_LINEAR);
+                  }
+
+                  /* The background passed to libpng, however, must be the
+                   * output (normally sRGB) value.
+                   */
+                  c.index = 0; /*unused*/
+                  c.gray = c.red = c.green = c.blue = (png_uint_16)gray;
+
+                  /* NOTE: the following is apparently a bug in libpng. Without
+                   * it the transparent color recognition in
+                   * png_set_background_fixed seems to go wrong.
+                   */
+                  expand_tRNS = 1;
+                  png_set_background_fixed(png_ptr, &c,
+                      PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                      0/*gamma: not used*/);
+               }
+
+               output_processing = PNG_CMAP_NONE;
+            }
+         }
+
+         else /* output is color */
+         {
+            /* We could use png_quantize here so long as there is no transparent
+             * color or alpha; png_quantize ignores alpha.  Easier overall just
+             * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube.
+             * Consequently we always want libpng to produce sRGB data.
+             */
+            data_encoding = P_sRGB;
+
+            /* Is there any transparency or alpha? */
+            if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+               png_ptr->num_trans > 0)
+            {
+               /* Is there alpha in the output too?  If so all four channels are
+                * processed into a special RGB cube with alpha support.
+                */
+               if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+               {
+                  png_uint_32 r;
+
+                  if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
+                     png_error(png_ptr, "rgb+alpha color-map: too few entries");
+
+                  cmap_entries = (unsigned int)make_rgb_colormap(display);
+
+                  /* Add a transparent entry. */
+                  png_create_colormap_entry(display, cmap_entries, 255, 255,
+                      255, 0, P_sRGB);
+
+                  /* This is stored as the background index for the processing
+                   * algorithm.
+                   */
+                  background_index = cmap_entries++;
+
+                  /* Add 27 r,g,b entries each with alpha 0.5. */
+                  for (r=0; r<256; r = (r << 1) | 0x7f)
+                  {
+                     png_uint_32 g;
+
+                     for (g=0; g<256; g = (g << 1) | 0x7f)
+                     {
+                        png_uint_32 b;
+
+                        /* This generates components with the values 0, 127 and
+                         * 255
+                         */
+                        for (b=0; b<256; b = (b << 1) | 0x7f)
+                           png_create_colormap_entry(display, cmap_entries++,
+                               r, g, b, 128, P_sRGB);
+                     }
+                  }
+
+                  expand_tRNS = 1;
+                  output_processing = PNG_CMAP_RGB_ALPHA;
+               }
+
+               else
+               {
+                  /* Alpha/transparency must be removed.  The background must
+                   * exist in the color map (achieved by setting adding it after
+                   * the 666 color-map).  If the standard processing code will
+                   * pick up this entry automatically that's all that is
+                   * required; libpng can be called to do the background
+                   * processing.
+                   */
+                  unsigned int sample_size =
+                     PNG_IMAGE_SAMPLE_SIZE(output_format);
+                  png_uint_32 r, g, b; /* sRGB background */
+
+                  if (PNG_RGB_COLORMAP_ENTRIES+1+27 > image->colormap_entries)
+                     png_error(png_ptr, "rgb-alpha color-map: too few entries");
+
+                  cmap_entries = (unsigned int)make_rgb_colormap(display);
+
+                  png_create_colormap_entry(display, cmap_entries, back_r,
+                      back_g, back_b, 0/*unused*/, output_encoding);
+
+                  if (output_encoding == P_LINEAR)
+                  {
+                     r = PNG_sRGB_FROM_LINEAR(back_r * 255);
+                     g = PNG_sRGB_FROM_LINEAR(back_g * 255);
+                     b = PNG_sRGB_FROM_LINEAR(back_b * 255);
+                  }
+
+                  else
+                  {
+                     r = back_r;
+                     g = back_g;
+                     b = back_g;
+                  }
+
+                  /* Compare the newly-created color-map entry with the one the
+                   * PNG_CMAP_RGB algorithm will use.  If the two entries don't
+                   * match, add the new one and set this as the background
+                   * index.
+                   */
+                  if (memcmp((png_const_bytep)display->colormap +
+                      sample_size * cmap_entries,
+                      (png_const_bytep)display->colormap +
+                          sample_size * PNG_RGB_INDEX(r,g,b),
+                     sample_size) != 0)
+                  {
+                     /* The background color must be added. */
+                     background_index = cmap_entries++;
+
+                     /* Add 27 r,g,b entries each with created by composing with
+                      * the background at alpha 0.5.
+                      */
+                     for (r=0; r<256; r = (r << 1) | 0x7f)
+                     {
+                        for (g=0; g<256; g = (g << 1) | 0x7f)
+                        {
+                           /* This generates components with the values 0, 127
+                            * and 255
+                            */
+                           for (b=0; b<256; b = (b << 1) | 0x7f)
+                              png_create_colormap_entry(display, cmap_entries++,
+                                  png_colormap_compose(display, r, P_sRGB, 128,
+                                      back_r, output_encoding),
+                                  png_colormap_compose(display, g, P_sRGB, 128,
+                                      back_g, output_encoding),
+                                  png_colormap_compose(display, b, P_sRGB, 128,
+                                      back_b, output_encoding),
+                                  0/*unused*/, output_encoding);
+                        }
+                     }
+
+                     expand_tRNS = 1;
+                     output_processing = PNG_CMAP_RGB_ALPHA;
+                  }
+
+                  else /* background color is in the standard color-map */
+                  {
+                     png_color_16 c;
+
+                     c.index = 0; /*unused*/
+                     c.red = (png_uint_16)back_r;
+                     c.gray = c.green = (png_uint_16)back_g;
+                     c.blue = (png_uint_16)back_b;
+
+                     png_set_background_fixed(png_ptr, &c,
+                         PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                         0/*gamma: not used*/);
+
+                     output_processing = PNG_CMAP_RGB;
+                  }
+               }
+            }
+
+            else /* no alpha or transparency in the input */
+            {
+               /* Alpha in the output is irrelevant, simply map the opaque input
+                * pixels to the 6x6x6 color-map.
+                */
+               if (PNG_RGB_COLORMAP_ENTRIES > image->colormap_entries)
+                  png_error(png_ptr, "rgb color-map: too few entries");
+
+               cmap_entries = (unsigned int)make_rgb_colormap(display);
+               output_processing = PNG_CMAP_RGB;
+            }
+         }
+         break;
+
+      case PNG_COLOR_TYPE_PALETTE:
+         /* It's already got a color-map.  It may be necessary to eliminate the
+          * tRNS entries though.
+          */
+         {
+            unsigned int num_trans = png_ptr->num_trans;
+            png_const_bytep trans = num_trans > 0 ? png_ptr->trans_alpha : NULL;
+            png_const_colorp colormap = png_ptr->palette;
+            const int do_background = trans != NULL &&
+               (output_format & PNG_FORMAT_FLAG_ALPHA) == 0;
+            unsigned int i;
+
+            /* Just in case: */
+            if (trans == NULL)
+               num_trans = 0;
+
+            output_processing = PNG_CMAP_NONE;
+            data_encoding = P_FILE; /* Don't change from color-map indices */
+            cmap_entries = (unsigned int)png_ptr->num_palette;
+            if (cmap_entries > 256)
+               cmap_entries = 256;
+
+            if (cmap_entries > (unsigned int)image->colormap_entries)
+               png_error(png_ptr, "palette color-map: too few entries");
+
+            for (i=0; i < cmap_entries; ++i)
+            {
+               if (do_background != 0 && i < num_trans && trans[i] < 255)
+               {
+                  if (trans[i] == 0)
+                     png_create_colormap_entry(display, i, back_r, back_g,
+                         back_b, 0, output_encoding);
+
+                  else
+                  {
+                     /* Must compose the PNG file color in the color-map entry
+                      * on the sRGB color in 'back'.
+                      */
+                     png_create_colormap_entry(display, i,
+                         png_colormap_compose(display, colormap[i].red,
+                             P_FILE, trans[i], back_r, output_encoding),
+                         png_colormap_compose(display, colormap[i].green,
+                             P_FILE, trans[i], back_g, output_encoding),
+                         png_colormap_compose(display, colormap[i].blue,
+                             P_FILE, trans[i], back_b, output_encoding),
+                         output_encoding == P_LINEAR ? trans[i] * 257U :
+                             trans[i],
+                         output_encoding);
+                  }
+               }
+
+               else
+                  png_create_colormap_entry(display, i, colormap[i].red,
+                      colormap[i].green, colormap[i].blue,
+                      i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/);
+            }
+
+            /* The PNG data may have indices packed in fewer than 8 bits, it
+             * must be expanded if so.
+             */
+            if (png_ptr->bit_depth < 8)
+               png_set_packing(png_ptr);
+         }
+         break;
+
+      default:
+         png_error(png_ptr, "invalid PNG color type");
+         /*NOT REACHED*/
+   }
+
+   /* Now deal with the output processing */
+   if (expand_tRNS != 0 && png_ptr->num_trans > 0 &&
+       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
+      png_set_tRNS_to_alpha(png_ptr);
+
+   switch (data_encoding)
+   {
+      case P_sRGB:
+         /* Change to 8-bit sRGB */
+         png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
+         /* FALLTHROUGH */
+
+      case P_FILE:
+         if (png_ptr->bit_depth > 8)
+            png_set_scale_16(png_ptr);
+         break;
+
+#ifdef __GNUC__
+      default:
+         png_error(png_ptr, "bad data option (internal error)");
+#endif
+   }
+
+   if (cmap_entries > 256 || cmap_entries > image->colormap_entries)
+      png_error(png_ptr, "color map overflow (BAD internal error)");
+
+   image->colormap_entries = cmap_entries;
+
+   /* Double check using the recorded background index */
+   switch (output_processing)
+   {
+      case PNG_CMAP_NONE:
+         if (background_index != PNG_CMAP_NONE_BACKGROUND)
+            goto bad_background;
+         break;
+
+      case PNG_CMAP_GA:
+         if (background_index != PNG_CMAP_GA_BACKGROUND)
+            goto bad_background;
+         break;
+
+      case PNG_CMAP_TRANS:
+         if (background_index >= cmap_entries ||
+            background_index != PNG_CMAP_TRANS_BACKGROUND)
+            goto bad_background;
+         break;
+
+      case PNG_CMAP_RGB:
+         if (background_index != PNG_CMAP_RGB_BACKGROUND)
+            goto bad_background;
+         break;
+
+      case PNG_CMAP_RGB_ALPHA:
+         if (background_index != PNG_CMAP_RGB_ALPHA_BACKGROUND)
+            goto bad_background;
+         break;
+
+      default:
+         png_error(png_ptr, "bad processing option (internal error)");
+
+      bad_background:
+         png_error(png_ptr, "bad background index (internal error)");
+   }
+
+   display->colormap_processing = (int)output_processing;
+
+   return 1/*ok*/;
+}
+
+/* The final part of the color-map read called from png_image_finish_read. */
+static int
+png_image_read_and_map(png_voidp argument)
+{
+   png_image_read_control *display = png_voidcast(png_image_read_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+   int passes;
+
+   /* Called when the libpng data must be transformed into the color-mapped
+    * form.  There is a local row buffer in display->local and this routine must
+    * do the interlace handling.
+    */
+   switch (png_ptr->interlaced)
+   {
+      case PNG_INTERLACE_NONE:
+         passes = 1;
+         break;
+
+      case PNG_INTERLACE_ADAM7:
+         passes = PNG_INTERLACE_ADAM7_PASSES;
+         break;
+
+      default:
+         png_error(png_ptr, "unknown interlace type");
+   }
+
+   {
+      png_uint_32  height = image->height;
+      png_uint_32  width = image->width;
+      int          proc = display->colormap_processing;
+      png_bytep    first_row = png_voidcast(png_bytep, display->first_row);
+      ptrdiff_t    step_row = display->row_bytes;
+      int pass;
+
+      for (pass = 0; pass < passes; ++pass)
+      {
+         unsigned int     startx, stepx, stepy;
+         png_uint_32      y;
+
+         if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+         {
+            /* The row may be empty for a short image: */
+            if (PNG_PASS_COLS(width, pass) == 0)
+               continue;
+
+            startx = PNG_PASS_START_COL(pass);
+            stepx = PNG_PASS_COL_OFFSET(pass);
+            y = PNG_PASS_START_ROW(pass);
+            stepy = PNG_PASS_ROW_OFFSET(pass);
+         }
+
+         else
+         {
+            y = 0;
+            startx = 0;
+            stepx = stepy = 1;
+         }
+
+         for (; y<height; y += stepy)
+         {
+            png_bytep inrow = png_voidcast(png_bytep, display->local_row);
+            png_bytep outrow = first_row + y * step_row;
+            png_const_bytep end_row = outrow + width;
+
+            /* Read read the libpng data into the temporary buffer. */
+            png_read_row(png_ptr, inrow, NULL);
+
+            /* Now process the row according to the processing option, note
+             * that the caller verifies that the format of the libpng output
+             * data is as required.
+             */
+            outrow += startx;
+            switch (proc)
+            {
+               case PNG_CMAP_GA:
+                  for (; outrow < end_row; outrow += stepx)
+                  {
+                     /* The data is always in the PNG order */
+                     unsigned int gray = *inrow++;
+                     unsigned int alpha = *inrow++;
+                     unsigned int entry;
+
+                     /* NOTE: this code is copied as a comment in
+                      * make_ga_colormap above.  Please update the
+                      * comment if you change this code!
+                      */
+                     if (alpha > 229) /* opaque */
+                     {
+                        entry = (231 * gray + 128) >> 8;
+                     }
+                     else if (alpha < 26) /* transparent */
+                     {
+                        entry = 231;
+                     }
+                     else /* partially opaque */
+                     {
+                        entry = 226 + 6 * PNG_DIV51(alpha) + PNG_DIV51(gray);
+                     }
+
+                     *outrow = (png_byte)entry;
+                  }
+                  break;
+
+               case PNG_CMAP_TRANS:
+                  for (; outrow < end_row; outrow += stepx)
+                  {
+                     png_byte gray = *inrow++;
+                     png_byte alpha = *inrow++;
+
+                     if (alpha == 0)
+                        *outrow = PNG_CMAP_TRANS_BACKGROUND;
+
+                     else if (gray != PNG_CMAP_TRANS_BACKGROUND)
+                        *outrow = gray;
+
+                     else
+                        *outrow = (png_byte)(PNG_CMAP_TRANS_BACKGROUND+1);
+                  }
+                  break;
+
+               case PNG_CMAP_RGB:
+                  for (; outrow < end_row; outrow += stepx)
+                  {
+                     *outrow = PNG_RGB_INDEX(inrow[0], inrow[1], inrow[2]);
+                     inrow += 3;
+                  }
+                  break;
+
+               case PNG_CMAP_RGB_ALPHA:
+                  for (; outrow < end_row; outrow += stepx)
+                  {
+                     unsigned int alpha = inrow[3];
+
+                     /* Because the alpha entries only hold alpha==0.5 values
+                      * split the processing at alpha==0.25 (64) and 0.75
+                      * (196).
+                      */
+
+                     if (alpha >= 196)
+                        *outrow = PNG_RGB_INDEX(inrow[0], inrow[1],
+                            inrow[2]);
+
+                     else if (alpha < 64)
+                        *outrow = PNG_CMAP_RGB_ALPHA_BACKGROUND;
+
+                     else
+                     {
+                        /* Likewise there are three entries for each of r, g
+                         * and b.  We could select the entry by popcount on
+                         * the top two bits on those architectures that
+                         * support it, this is what the code below does,
+                         * crudely.
+                         */
+                        unsigned int back_i = PNG_CMAP_RGB_ALPHA_BACKGROUND+1;
+
+                        /* Here are how the values map:
+                         *
+                         * 0x00 .. 0x3f -> 0
+                         * 0x40 .. 0xbf -> 1
+                         * 0xc0 .. 0xff -> 2
+                         *
+                         * So, as above with the explicit alpha checks, the
+                         * breakpoints are at 64 and 196.
+                         */
+                        if (inrow[0] & 0x80) back_i += 9; /* red */
+                        if (inrow[0] & 0x40) back_i += 9;
+                        if (inrow[0] & 0x80) back_i += 3; /* green */
+                        if (inrow[0] & 0x40) back_i += 3;
+                        if (inrow[0] & 0x80) back_i += 1; /* blue */
+                        if (inrow[0] & 0x40) back_i += 1;
+
+                        *outrow = (png_byte)back_i;
+                     }
+
+                     inrow += 4;
+                  }
+                  break;
+
+               default:
+                  break;
+            }
+         }
+      }
+   }
+
+   return 1;
+}
+
+static int
+png_image_read_colormapped(png_voidp argument)
+{
+   png_image_read_control *display = png_voidcast(png_image_read_control*,
+       argument);
+   png_imagep image = display->image;
+   png_controlp control = image->opaque;
+   png_structrp png_ptr = control->png_ptr;
+   png_inforp info_ptr = control->info_ptr;
+
+   int passes = 0; /* As a flag */
+
+   PNG_SKIP_CHUNKS(png_ptr);
+
+   /* Update the 'info' structure and make sure the result is as required; first
+    * make sure to turn on the interlace handling if it will be required
+    * (because it can't be turned on *after* the call to png_read_update_info!)
+    */
+   if (display->colormap_processing == PNG_CMAP_NONE)
+      passes = png_set_interlace_handling(png_ptr);
+
+   png_read_update_info(png_ptr, info_ptr);
+
+   /* The expected output can be deduced from the colormap_processing option. */
+   switch (display->colormap_processing)
+   {
+      case PNG_CMAP_NONE:
+         /* Output must be one channel and one byte per pixel, the output
+          * encoding can be anything.
+          */
+         if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+            info_ptr->color_type == PNG_COLOR_TYPE_GRAY) &&
+            info_ptr->bit_depth == 8)
+            break;
+
+         goto bad_output;
+
+      case PNG_CMAP_TRANS:
+      case PNG_CMAP_GA:
+         /* Output must be two channels and the 'G' one must be sRGB, the latter
+          * can be checked with an exact number because it should have been set
+          * to this number above!
+          */
+         if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+            info_ptr->bit_depth == 8 &&
+            png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+            image->colormap_entries == 256)
+            break;
+
+         goto bad_output;
+
+      case PNG_CMAP_RGB:
+         /* Output must be 8-bit sRGB encoded RGB */
+         if (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+            info_ptr->bit_depth == 8 &&
+            png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+            image->colormap_entries == 216)
+            break;
+
+         goto bad_output;
+
+      case PNG_CMAP_RGB_ALPHA:
+         /* Output must be 8-bit sRGB encoded RGBA */
+         if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+            info_ptr->bit_depth == 8 &&
+            png_ptr->screen_gamma == PNG_GAMMA_sRGB &&
+            image->colormap_entries == 244 /* 216 + 1 + 27 */)
+            break;
+
+         goto bad_output;
+
+      default:
+      bad_output:
+         png_error(png_ptr, "bad color-map processing (internal error)");
+   }
+
+   /* Now read the rows.  Do this here if it is possible to read directly into
+    * the output buffer, otherwise allocate a local row buffer of the maximum
+    * size libpng requires and call the relevant processing routine safely.
+    */
+   {
+      png_voidp first_row = display->buffer;
+      ptrdiff_t row_bytes = display->row_stride;
+
+      /* The following expression is designed to work correctly whether it gives
+       * a signed or an unsigned result.
+       */
+      if (row_bytes < 0)
+      {
+         char *ptr = png_voidcast(char*, first_row);
+         ptr += (image->height-1) * (-row_bytes);
+         first_row = png_voidcast(png_voidp, ptr);
+      }
+
+      display->first_row = first_row;
+      display->row_bytes = row_bytes;
+   }
+
+   if (passes == 0)
+   {
+      int result;
+      png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+      display->local_row = row;
+      result = png_safe_execute(image, png_image_read_and_map, display);
+      display->local_row = NULL;
+      png_free(png_ptr, row);
+
+      return result;
+   }
+
+   else
+   {
+      png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes;
+
+      while (--passes >= 0)
+      {
+         png_uint_32      y = image->height;
+         png_bytep        row = png_voidcast(png_bytep, display->first_row);
+
+         for (; y > 0; --y)
+         {
+            png_read_row(png_ptr, row, NULL);
+            row += row_bytes;
+         }
+      }
+
+      return 1;
+   }
+}
+
+/* Just the row reading part of png_image_read. */
+static int
+png_image_read_composite(png_voidp argument)
+{
+   png_image_read_control *display = png_voidcast(png_image_read_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+   int passes;
+
+   switch (png_ptr->interlaced)
+   {
+      case PNG_INTERLACE_NONE:
+         passes = 1;
+         break;
+
+      case PNG_INTERLACE_ADAM7:
+         passes = PNG_INTERLACE_ADAM7_PASSES;
+         break;
+
+      default:
+         png_error(png_ptr, "unknown interlace type");
+   }
+
+   {
+      png_uint_32  height = image->height;
+      png_uint_32  width = image->width;
+      ptrdiff_t    step_row = display->row_bytes;
+      unsigned int channels =
+          (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
+      int pass;
+
+      for (pass = 0; pass < passes; ++pass)
+      {
+         unsigned int     startx, stepx, stepy;
+         png_uint_32      y;
+
+         if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+         {
+            /* The row may be empty for a short image: */
+            if (PNG_PASS_COLS(width, pass) == 0)
+               continue;
+
+            startx = PNG_PASS_START_COL(pass) * channels;
+            stepx = PNG_PASS_COL_OFFSET(pass) * channels;
+            y = PNG_PASS_START_ROW(pass);
+            stepy = PNG_PASS_ROW_OFFSET(pass);
+         }
+
+         else
+         {
+            y = 0;
+            startx = 0;
+            stepx = channels;
+            stepy = 1;
+         }
+
+         for (; y<height; y += stepy)
+         {
+            png_bytep inrow = png_voidcast(png_bytep, display->local_row);
+            png_bytep outrow;
+            png_const_bytep end_row;
+
+            /* Read the row, which is packed: */
+            png_read_row(png_ptr, inrow, NULL);
+
+            outrow = png_voidcast(png_bytep, display->first_row);
+            outrow += y * step_row;
+            end_row = outrow + width * channels;
+
+            /* Now do the composition on each pixel in this row. */
+            outrow += startx;
+            for (; outrow < end_row; outrow += stepx)
+            {
+               png_byte alpha = inrow[channels];
+
+               if (alpha > 0) /* else no change to the output */
+               {
+                  unsigned int c;
+
+                  for (c=0; c<channels; ++c)
+                  {
+                     png_uint_32 component = inrow[c];
+
+                     if (alpha < 255) /* else just use component */
+                     {
+                        /* This is PNG_OPTIMIZED_ALPHA, the component value
+                         * is a linear 8-bit value.  Combine this with the
+                         * current outrow[c] value which is sRGB encoded.
+                         * Arithmetic here is 16-bits to preserve the output
+                         * values correctly.
+                         */
+                        component *= 257*255; /* =65535 */
+                        component += (255-alpha)*png_sRGB_table[outrow[c]];
+
+                        /* So 'component' is scaled by 255*65535 and is
+                         * therefore appropriate for the sRGB to linear
+                         * conversion table.
+                         */
+                        component = PNG_sRGB_FROM_LINEAR(component);
+                     }
+
+                     outrow[c] = (png_byte)component;
+                  }
+               }
+
+               inrow += channels+1; /* components and alpha channel */
+            }
+         }
+      }
+   }
+
+   return 1;
+}
+
+/* The do_local_background case; called when all the following transforms are to
+ * be done:
+ *
+ * PNG_RGB_TO_GRAY
+ * PNG_COMPOSITE
+ * PNG_GAMMA
+ *
+ * This is a work-around for the fact that both the PNG_RGB_TO_GRAY and
+ * PNG_COMPOSITE code performs gamma correction, so we get double gamma
+ * correction.  The fix-up is to prevent the PNG_COMPOSITE operation from
+ * happening inside libpng, so this routine sees an 8 or 16-bit gray+alpha
+ * row and handles the removal or pre-multiplication of the alpha channel.
+ */
+static int
+png_image_read_background(png_voidp argument)
+{
+   png_image_read_control *display = png_voidcast(png_image_read_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+   png_inforp info_ptr = image->opaque->info_ptr;
+   png_uint_32 height = image->height;
+   png_uint_32 width = image->width;
+   int pass, passes;
+
+   /* Double check the convoluted logic below.  We expect to get here with
+    * libpng doing rgb to gray and gamma correction but background processing
+    * left to the png_image_read_background function.  The rows libpng produce
+    * might be 8 or 16-bit but should always have two channels; gray plus alpha.
+    */
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+      png_error(png_ptr, "lost rgb to gray");
+
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+      png_error(png_ptr, "unexpected compose");
+
+   if (png_get_channels(png_ptr, info_ptr) != 2)
+      png_error(png_ptr, "lost/gained channels");
+
+   /* Expect the 8-bit case to always remove the alpha channel */
+   if ((image->format & PNG_FORMAT_FLAG_LINEAR) == 0 &&
+      (image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+      png_error(png_ptr, "unexpected 8-bit transformation");
+
+   switch (png_ptr->interlaced)
+   {
+      case PNG_INTERLACE_NONE:
+         passes = 1;
+         break;
+
+      case PNG_INTERLACE_ADAM7:
+         passes = PNG_INTERLACE_ADAM7_PASSES;
+         break;
+
+      default:
+         png_error(png_ptr, "unknown interlace type");
+   }
+
+   /* Use direct access to info_ptr here because otherwise the simplified API
+    * would require PNG_EASY_ACCESS_SUPPORTED (just for this.)  Note this is
+    * checking the value after libpng expansions, not the original value in the
+    * PNG.
+    */
+   switch (info_ptr->bit_depth)
+   {
+      case 8:
+         /* 8-bit sRGB gray values with an alpha channel; the alpha channel is
+          * to be removed by composing on a background: either the row if
+          * display->background is NULL or display->background->green if not.
+          * Unlike the code above ALPHA_OPTIMIZED has *not* been done.
+          */
+         {
+            png_bytep first_row = png_voidcast(png_bytep, display->first_row);
+            ptrdiff_t step_row = display->row_bytes;
+
+            for (pass = 0; pass < passes; ++pass)
+            {
+               png_bytep row = png_voidcast(png_bytep, display->first_row);
+               unsigned int     startx, stepx, stepy;
+               png_uint_32      y;
+
+               if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+               {
+                  /* The row may be empty for a short image: */
+                  if (PNG_PASS_COLS(width, pass) == 0)
+                     continue;
+
+                  startx = PNG_PASS_START_COL(pass);
+                  stepx = PNG_PASS_COL_OFFSET(pass);
+                  y = PNG_PASS_START_ROW(pass);
+                  stepy = PNG_PASS_ROW_OFFSET(pass);
+               }
+
+               else
+               {
+                  y = 0;
+                  startx = 0;
+                  stepx = stepy = 1;
+               }
+
+               if (display->background == NULL)
+               {
+                  for (; y<height; y += stepy)
+                  {
+                     png_bytep inrow = png_voidcast(png_bytep,
+                         display->local_row);
+                     png_bytep outrow = first_row + y * step_row;
+                     png_const_bytep end_row = outrow + width;
+
+                     /* Read the row, which is packed: */
+                     png_read_row(png_ptr, inrow, NULL);
+
+                     /* Now do the composition on each pixel in this row. */
+                     outrow += startx;
+                     for (; outrow < end_row; outrow += stepx)
+                     {
+                        png_byte alpha = inrow[1];
+
+                        if (alpha > 0) /* else no change to the output */
+                        {
+                           png_uint_32 component = inrow[0];
+
+                           if (alpha < 255) /* else just use component */
+                           {
+                              /* Since PNG_OPTIMIZED_ALPHA was not set it is
+                               * necessary to invert the sRGB transfer
+                               * function and multiply the alpha out.
+                               */
+                              component = png_sRGB_table[component] * alpha;
+                              component += png_sRGB_table[outrow[0]] *
+                                 (255-alpha);
+                              component = PNG_sRGB_FROM_LINEAR(component);
+                           }
+
+                           outrow[0] = (png_byte)component;
+                        }
+
+                        inrow += 2; /* gray and alpha channel */
+                     }
+                  }
+               }
+
+               else /* constant background value */
+               {
+                  png_byte background8 = display->background->green;
+                  png_uint_16 background = png_sRGB_table[background8];
+
+                  for (; y<height; y += stepy)
+                  {
+                     png_bytep inrow = png_voidcast(png_bytep,
+                         display->local_row);
+                     png_bytep outrow = first_row + y * step_row;
+                     png_const_bytep end_row = outrow + width;
+
+                     /* Read the row, which is packed: */
+                     png_read_row(png_ptr, inrow, NULL);
+
+                     /* Now do the composition on each pixel in this row. */
+                     outrow += startx;
+                     for (; outrow < end_row; outrow += stepx)
+                     {
+                        png_byte alpha = inrow[1];
+
+                        if (alpha > 0) /* else use background */
+                        {
+                           png_uint_32 component = inrow[0];
+
+                           if (alpha < 255) /* else just use component */
+                           {
+                              component = png_sRGB_table[component] * alpha;
+                              component += background * (255-alpha);
+                              component = PNG_sRGB_FROM_LINEAR(component);
+                           }
+
+                           outrow[0] = (png_byte)component;
+                        }
+
+                        else
+                           outrow[0] = background8;
+
+                        inrow += 2; /* gray and alpha channel */
+                     }
+
+                     row += display->row_bytes;
+                  }
+               }
+            }
+         }
+         break;
+
+      case 16:
+         /* 16-bit linear with pre-multiplied alpha; the pre-multiplication must
+          * still be done and, maybe, the alpha channel removed.  This code also
+          * handles the alpha-first option.
+          */
+         {
+            png_uint_16p first_row = png_voidcast(png_uint_16p,
+                display->first_row);
+            /* The division by two is safe because the caller passed in a
+             * stride which was multiplied by 2 (below) to get row_bytes.
+             */
+            ptrdiff_t    step_row = display->row_bytes / 2;
+            unsigned int preserve_alpha = (image->format &
+                PNG_FORMAT_FLAG_ALPHA) != 0;
+            unsigned int outchannels = 1U+preserve_alpha;
+            int swap_alpha = 0;
+
+#           ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+               if (preserve_alpha != 0 &&
+                   (image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+                  swap_alpha = 1;
+#           endif
+
+            for (pass = 0; pass < passes; ++pass)
+            {
+               unsigned int     startx, stepx, stepy;
+               png_uint_32      y;
+
+               /* The 'x' start and step are adjusted to output components here.
+                */
+               if (png_ptr->interlaced == PNG_INTERLACE_ADAM7)
+               {
+                  /* The row may be empty for a short image: */
+                  if (PNG_PASS_COLS(width, pass) == 0)
+                     continue;
+
+                  startx = PNG_PASS_START_COL(pass) * outchannels;
+                  stepx = PNG_PASS_COL_OFFSET(pass) * outchannels;
+                  y = PNG_PASS_START_ROW(pass);
+                  stepy = PNG_PASS_ROW_OFFSET(pass);
+               }
+
+               else
+               {
+                  y = 0;
+                  startx = 0;
+                  stepx = outchannels;
+                  stepy = 1;
+               }
+
+               for (; y<height; y += stepy)
+               {
+                  png_const_uint_16p inrow;
+                  png_uint_16p outrow = first_row + y*step_row;
+                  png_uint_16p end_row = outrow + width * outchannels;
+
+                  /* Read the row, which is packed: */
+                  png_read_row(png_ptr, png_voidcast(png_bytep,
+                      display->local_row), NULL);
+                  inrow = png_voidcast(png_const_uint_16p, display->local_row);
+
+                  /* Now do the pre-multiplication on each pixel in this row.
+                   */
+                  outrow += startx;
+                  for (; outrow < end_row; outrow += stepx)
+                  {
+                     png_uint_32 component = inrow[0];
+                     png_uint_16 alpha = inrow[1];
+
+                     if (alpha > 0) /* else 0 */
+                     {
+                        if (alpha < 65535) /* else just use component */
+                        {
+                           component *= alpha;
+                           component += 32767;
+                           component /= 65535;
+                        }
+                     }
+
+                     else
+                        component = 0;
+
+                     outrow[swap_alpha] = (png_uint_16)component;
+                     if (preserve_alpha != 0)
+                        outrow[1 ^ swap_alpha] = alpha;
+
+                     inrow += 2; /* components and alpha channel */
+                  }
+               }
+            }
+         }
+         break;
+
+#ifdef __GNUC__
+      default:
+         png_error(png_ptr, "unexpected bit depth");
+#endif
+   }
+
+   return 1;
+}
+
+/* The guts of png_image_finish_read as a png_safe_execute callback. */
+static int
+png_image_read_direct(png_voidp argument)
+{
+   png_image_read_control *display = png_voidcast(png_image_read_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+   png_inforp info_ptr = image->opaque->info_ptr;
+
+   png_uint_32 format = image->format;
+   int linear = (format & PNG_FORMAT_FLAG_LINEAR) != 0;
+   int do_local_compose = 0;
+   int do_local_background = 0; /* to avoid double gamma correction bug */
+   int passes = 0;
+
+   /* Add transforms to ensure the correct output format is produced then check
+    * that the required implementation support is there.  Always expand; always
+    * need 8 bits minimum, no palette and expanded tRNS.
+    */
+   png_set_expand(png_ptr);
+
+   /* Now check the format to see if it was modified. */
+   {
+      png_uint_32 base_format = png_image_format(png_ptr) &
+         ~PNG_FORMAT_FLAG_COLORMAP /* removed by png_set_expand */;
+      png_uint_32 change = format ^ base_format;
+      png_fixed_point output_gamma;
+      int mode; /* alpha mode */
+
+      /* Do this first so that we have a record if rgb to gray is happening. */
+      if ((change & PNG_FORMAT_FLAG_COLOR) != 0)
+      {
+         /* gray<->color transformation required. */
+         if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
+            png_set_gray_to_rgb(png_ptr);
+
+         else
+         {
+            /* libpng can't do both rgb to gray and
+             * background/pre-multiplication if there is also significant gamma
+             * correction, because both operations require linear colors and
+             * the code only supports one transform doing the gamma correction.
+             * Handle this by doing the pre-multiplication or background
+             * operation in this code, if necessary.
+             *
+             * TODO: fix this by rewriting pngrtran.c (!)
+             *
+             * For the moment (given that fixing this in pngrtran.c is an
+             * enormous change) 'do_local_background' is used to indicate that
+             * the problem exists.
+             */
+            if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+               do_local_background = 1/*maybe*/;
+
+            png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
+                PNG_RGB_TO_GRAY_DEFAULT, PNG_RGB_TO_GRAY_DEFAULT);
+         }
+
+         change &= ~PNG_FORMAT_FLAG_COLOR;
+      }
+
+      /* Set the gamma appropriately, linear for 16-bit input, sRGB otherwise.
+       */
+      {
+         png_fixed_point input_gamma_default;
+
+         if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
+             (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+            input_gamma_default = PNG_GAMMA_LINEAR;
+         else
+            input_gamma_default = PNG_DEFAULT_sRGB;
+
+         /* Call png_set_alpha_mode to set the default for the input gamma; the
+          * output gamma is set by a second call below.
+          */
+         png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default);
+      }
+
+      if (linear != 0)
+      {
+         /* If there *is* an alpha channel in the input it must be multiplied
+          * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG.
+          */
+         if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+            mode = PNG_ALPHA_STANDARD; /* associated alpha */
+
+         else
+            mode = PNG_ALPHA_PNG;
+
+         output_gamma = PNG_GAMMA_LINEAR;
+      }
+
+      else
+      {
+         mode = PNG_ALPHA_PNG;
+         output_gamma = PNG_DEFAULT_sRGB;
+      }
+      
+      if ((change & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0)
+      {
+         mode = PNG_ALPHA_OPTIMIZED;
+         change &= ~PNG_FORMAT_FLAG_ASSOCIATED_ALPHA;
+      }
+      
+      /* If 'do_local_background' is set check for the presence of gamma
+       * correction; this is part of the work-round for the libpng bug
+       * described above.
+       *
+       * TODO: fix libpng and remove this.
+       */
+      if (do_local_background != 0)
+      {
+         png_fixed_point gtest;
+
+         /* This is 'png_gamma_threshold' from pngrtran.c; the test used for
+          * gamma correction, the screen gamma hasn't been set on png_struct
+          * yet; it's set below.  png_struct::gamma, however, is set to the
+          * final value.
+          */
+         if (png_muldiv(&gtest, output_gamma, png_ptr->colorspace.gamma,
+             PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0)
+            do_local_background = 0;
+
+         else if (mode == PNG_ALPHA_STANDARD)
+         {
+            do_local_background = 2/*required*/;
+            mode = PNG_ALPHA_PNG; /* prevent libpng doing it */
+         }
+
+         /* else leave as 1 for the checks below */
+      }
+
+      /* If the bit-depth changes then handle that here. */
+      if ((change & PNG_FORMAT_FLAG_LINEAR) != 0)
+      {
+         if (linear != 0 /*16-bit output*/)
+            png_set_expand_16(png_ptr);
+
+         else /* 8-bit output */
+            png_set_scale_16(png_ptr);
+
+         change &= ~PNG_FORMAT_FLAG_LINEAR;
+      }
+
+      /* Now the background/alpha channel changes. */
+      if ((change & PNG_FORMAT_FLAG_ALPHA) != 0)
+      {
+         /* Removing an alpha channel requires composition for the 8-bit
+          * formats; for the 16-bit it is already done, above, by the
+          * pre-multiplication and the channel just needs to be stripped.
+          */
+         if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
+         {
+            /* If RGB->gray is happening the alpha channel must be left and the
+             * operation completed locally.
+             *
+             * TODO: fix libpng and remove this.
+             */
+            if (do_local_background != 0)
+               do_local_background = 2/*required*/;
+
+            /* 16-bit output: just remove the channel */
+            else if (linear != 0) /* compose on black (well, pre-multiply) */
+               png_set_strip_alpha(png_ptr);
+
+            /* 8-bit output: do an appropriate compose */
+            else if (display->background != NULL)
+            {
+               png_color_16 c;
+
+               c.index = 0; /*unused*/
+               c.red = display->background->red;
+               c.green = display->background->green;
+               c.blue = display->background->blue;
+               c.gray = display->background->green;
+
+               /* This is always an 8-bit sRGB value, using the 'green' channel
+                * for gray is much better than calculating the luminance here;
+                * we can get off-by-one errors in that calculation relative to
+                * the app expectations and that will show up in transparent
+                * pixels.
+                */
+               png_set_background_fixed(png_ptr, &c,
+                   PNG_BACKGROUND_GAMMA_SCREEN, 0/*need_expand*/,
+                   0/*gamma: not used*/);
+            }
+
+            else /* compose on row: implemented below. */
+            {
+               do_local_compose = 1;
+               /* This leaves the alpha channel in the output, so it has to be
+                * removed by the code below.  Set the encoding to the 'OPTIMIZE'
+                * one so the code only has to hack on the pixels that require
+                * composition.
+                */
+               mode = PNG_ALPHA_OPTIMIZED;
+            }
+         }
+
+         else /* output needs an alpha channel */
+         {
+            /* This is tricky because it happens before the swap operation has
+             * been accomplished; however, the swap does *not* swap the added
+             * alpha channel (weird API), so it must be added in the correct
+             * place.
+             */
+            png_uint_32 filler; /* opaque filler */
+            int where;
+
+            if (linear != 0)
+               filler = 65535;
+
+            else
+               filler = 255;
+
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
+            if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+            {
+               where = PNG_FILLER_BEFORE;
+               change &= ~PNG_FORMAT_FLAG_AFIRST;
+            }
+
+            else
+#endif
+            where = PNG_FILLER_AFTER;
+
+            png_set_add_alpha(png_ptr, filler, where);
+         }
+
+         /* This stops the (irrelevant) call to swap_alpha below. */
+         change &= ~PNG_FORMAT_FLAG_ALPHA;
+      }
+
+      /* Now set the alpha mode correctly; this is always done, even if there is
+       * no alpha channel in either the input or the output because it correctly
+       * sets the output gamma.
+       */
+      png_set_alpha_mode_fixed(png_ptr, mode, output_gamma);
+
+#     ifdef PNG_FORMAT_BGR_SUPPORTED
+         if ((change & PNG_FORMAT_FLAG_BGR) != 0)
+         {
+            /* Check only the output format; PNG is never BGR; don't do this if
+             * the output is gray, but fix up the 'format' value in that case.
+             */
+            if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
+               png_set_bgr(png_ptr);
+
+            else
+               format &= ~PNG_FORMAT_FLAG_BGR;
+
+            change &= ~PNG_FORMAT_FLAG_BGR;
+         }
+#     endif
+
+#     ifdef PNG_FORMAT_AFIRST_SUPPORTED
+         if ((change & PNG_FORMAT_FLAG_AFIRST) != 0)
+         {
+            /* Only relevant if there is an alpha channel - it's particularly
+             * important to handle this correctly because do_local_compose may
+             * be set above and then libpng will keep the alpha channel for this
+             * code to remove.
+             */
+            if ((format & PNG_FORMAT_FLAG_ALPHA) != 0)
+            {
+               /* Disable this if doing a local background,
+                * TODO: remove this when local background is no longer required.
+                */
+               if (do_local_background != 2)
+                  png_set_swap_alpha(png_ptr);
+            }
+
+            else
+               format &= ~PNG_FORMAT_FLAG_AFIRST;
+
+            change &= ~PNG_FORMAT_FLAG_AFIRST;
+         }
+#     endif
+
+      /* If the *output* is 16-bit then we need to check for a byte-swap on this
+       * architecture.
+       */
+      if (linear != 0)
+      {
+         PNG_CONST png_uint_16 le = 0x0001;
+
+         if ((*(png_const_bytep) & le) != 0)
+            png_set_swap(png_ptr);
+      }
+
+      /* If change is not now 0 some transformation is missing - error out. */
+      if (change != 0)
+         png_error(png_ptr, "png_read_image: unsupported transformation");
+   }
+
+   PNG_SKIP_CHUNKS(png_ptr);
+
+   /* Update the 'info' structure and make sure the result is as required; first
+    * make sure to turn on the interlace handling if it will be required
+    * (because it can't be turned on *after* the call to png_read_update_info!)
+    *
+    * TODO: remove the do_local_background fixup below.
+    */
+   if (do_local_compose == 0 && do_local_background != 2)
+      passes = png_set_interlace_handling(png_ptr);
+
+   png_read_update_info(png_ptr, info_ptr);
+
+   {
+      png_uint_32 info_format = 0;
+
+      if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+         info_format |= PNG_FORMAT_FLAG_COLOR;
+
+      if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      {
+         /* do_local_compose removes this channel below. */
+         if (do_local_compose == 0)
+         {
+            /* do_local_background does the same if required. */
+            if (do_local_background != 2 ||
+               (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+               info_format |= PNG_FORMAT_FLAG_ALPHA;
+         }
+      }
+
+      else if (do_local_compose != 0) /* internal error */
+         png_error(png_ptr, "png_image_read: alpha channel lost");
+
+      if ((format & PNG_FORMAT_FLAG_ASSOCIATED_ALPHA) != 0) {
+         info_format |= PNG_FORMAT_FLAG_ASSOCIATED_ALPHA;
+      }
+
+      if (info_ptr->bit_depth == 16)
+         info_format |= PNG_FORMAT_FLAG_LINEAR;
+
+#ifdef PNG_FORMAT_BGR_SUPPORTED
+      if ((png_ptr->transformations & PNG_BGR) != 0)
+         info_format |= PNG_FORMAT_FLAG_BGR;
+#endif
+
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
+         if (do_local_background == 2)
+         {
+            if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+               info_format |= PNG_FORMAT_FLAG_AFIRST;
+         }
+
+         if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0 ||
+            ((png_ptr->transformations & PNG_ADD_ALPHA) != 0 &&
+            (png_ptr->flags & PNG_FLAG_FILLER_AFTER) == 0))
+         {
+            if (do_local_background == 2)
+               png_error(png_ptr, "unexpected alpha swap transformation");
+
+            info_format |= PNG_FORMAT_FLAG_AFIRST;
+         }
+#     endif
+
+      /* This is actually an internal error. */
+      if (info_format != format)
+         png_error(png_ptr, "png_read_image: invalid transformations");
+   }
+
+   /* Now read the rows.  If do_local_compose is set then it is necessary to use
+    * a local row buffer.  The output will be GA, RGBA or BGRA and must be
+    * converted to G, RGB or BGR as appropriate.  The 'local_row' member of the
+    * display acts as a flag.
+    */
+   {
+      png_voidp first_row = display->buffer;
+      ptrdiff_t row_bytes = display->row_stride;
+
+      if (linear != 0)
+         row_bytes *= 2;
+
+      /* The following expression is designed to work correctly whether it gives
+       * a signed or an unsigned result.
+       */
+      if (row_bytes < 0)
+      {
+         char *ptr = png_voidcast(char*, first_row);
+         ptr += (image->height-1) * (-row_bytes);
+         first_row = png_voidcast(png_voidp, ptr);
+      }
+
+      display->first_row = first_row;
+      display->row_bytes = row_bytes;
+   }
+
+   if (do_local_compose != 0)
+   {
+      int result;
+      png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+      display->local_row = row;
+      result = png_safe_execute(image, png_image_read_composite, display);
+      display->local_row = NULL;
+      png_free(png_ptr, row);
+
+      return result;
+   }
+
+   else if (do_local_background == 2)
+   {
+      int result;
+      png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
+
+      display->local_row = row;
+      result = png_safe_execute(image, png_image_read_background, display);
+      display->local_row = NULL;
+      png_free(png_ptr, row);
+
+      return result;
+   }
+
+   else
+   {
+      png_alloc_size_t row_bytes = (png_alloc_size_t)display->row_bytes;
+
+      while (--passes >= 0)
+      {
+         png_uint_32      y = image->height;
+         png_bytep        row = png_voidcast(png_bytep, display->first_row);
+
+         for (; y > 0; --y)
+         {
+            png_read_row(png_ptr, row, NULL);
+            row += row_bytes;
+         }
+      }
+
+      return 1;
+   }
+}
+
+int PNGAPI
+png_image_finish_read(png_imagep image, png_const_colorp background,
+    void *buffer, png_int_32 row_stride, void *colormap)
+{
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      /* Check for row_stride overflow.  This check is not performed on the
+       * original PNG format because it may not occur in the output PNG format
+       * and libpng deals with the issues of reading the original.
+       */
+      const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format);
+
+      /* The following checks just the 'row_stride' calculation to ensure it
+       * fits in a signed 32-bit value.  Because channels/components can be
+       * either 1 or 2 bytes in size the length of a row can still overflow 32
+       * bits; this is just to verify that the 'row_stride' argument can be
+       * represented.
+       */
+      if (image->width <= 0x7fffffffU/channels) /* no overflow */
+      {
+         png_uint_32 check;
+         const png_uint_32 png_row_stride = image->width * channels;
+
+         if (row_stride == 0)
+            row_stride = (png_int_32)/*SAFE*/png_row_stride;
+
+         if (row_stride < 0)
+            check = (png_uint_32)(-row_stride);
+
+         else
+            check = (png_uint_32)row_stride;
+
+         /* This verifies 'check', the absolute value of the actual stride
+          * passed in and detects overflow in the application calculation (i.e.
+          * if the app did actually pass in a non-zero 'row_stride'.
+          */
+         if (image->opaque != NULL && buffer != NULL && check >= png_row_stride)
+         {
+            /* Now check for overflow of the image buffer calculation; this
+             * limits the whole image size to 32 bits for API compatibility with
+             * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro.
+             *
+             * The PNG_IMAGE_BUFFER_SIZE macro is:
+             *
+             *    (PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)*height*(row_stride))
+             *
+             * And the component size is always 1 or 2, so make sure that the
+             * number of *bytes* that the application is saying are available
+             * does actually fit into a 32-bit number.
+             *
+             * NOTE: this will be changed in 1.7 because PNG_IMAGE_BUFFER_SIZE
+             * will be changed to use png_alloc_size_t; bigger images can be
+             * accomodated on 64-bit systems.
+             */
+            if (image->height <=
+                0xffffffffU/PNG_IMAGE_PIXEL_COMPONENT_SIZE(image->format)/check)
+            {
+               if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
+                  (image->colormap_entries > 0 && colormap != NULL))
+               {
+                  int result;
+                  png_image_read_control display;
+
+                  memset(&display, 0, (sizeof display));
+                  display.image = image;
+                  display.buffer = buffer;
+                  display.row_stride = row_stride;
+                  display.colormap = colormap;
+                  display.background = background;
+                  display.local_row = NULL;
+
+                  /* Choose the correct 'end' routine; for the color-map case
+                   * all the setup has already been done.
+                   */
+                  if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+                     result =
+                         png_safe_execute(image,
+                             png_image_read_colormap, &display) &&
+                             png_safe_execute(image,
+                             png_image_read_colormapped, &display);
+
+                  else
+                     result =
+                        png_safe_execute(image,
+                            png_image_read_direct, &display);
+
+                  png_image_free(image);
+                  return result;
+               }
+
+               else
+                  return png_image_error(image,
+                      "png_image_finish_read[color-map]: no color-map");
+            }
+
+            else
+               return png_image_error(image,
+                   "png_image_finish_read: image too large");
+         }
+
+         else
+            return png_image_error(image,
+                "png_image_finish_read: invalid argument");
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_finish_read: row_stride too large");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_finish_read: damaged PNG_IMAGE_VERSION");
+
+   return 0;
+}
+
+#endif /* SIMPLIFIED_READ */
+#endif /* READ */
diff --git a/xs/src/png/libpng/pngrio.c b/xs/src/png/libpng/pngrio.c
new file mode 100644
index 000000000..7e26e855c
--- /dev/null
+++ b/xs/src/png/libpng/pngrio.c
@@ -0,0 +1,120 @@
+
+/* pngrio.c - functions for data input
+ *
+ * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all input.  Users who need
+ * special handling are expected to write a function that has the same
+ * arguments as this and performs a similar function, but that possibly
+ * has a different input method.  Note that you shouldn't change this
+ * function, but rather write a replacement function and then make
+ * libpng use it at run time with png_set_read_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Read the data from whatever input you are using.  The default routine
+ * reads from a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads.  This should never be asked
+ * to read more than 64K on a 16-bit machine.
+ */
+void /* PRIVATE */
+png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
+{
+   png_debug1(4, "reading %d bytes", (int)length);
+
+   if (png_ptr->read_data_fn != NULL)
+      (*(png_ptr->read_data_fn))(png_ptr, data, length);
+
+   else
+      png_error(png_ptr, "Call to NULL read function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual reading of data.  If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   if (png_ptr == NULL)
+      return;
+
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
+
+   if (check != length)
+      png_error(png_ptr, "Read Error");
+}
+#endif
+
+/* This function allows the application to supply a new input function
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ *
+ * png_ptr      - pointer to a png input data structure
+ *
+ * io_ptr       - pointer to user supplied structure containing info about
+ *                the input functions.  May be NULL.
+ *
+ * read_data_fn - pointer to a new input function that takes as its
+ *                arguments a pointer to a png_struct, a pointer to
+ *                a location where input data can be stored, and a 32-bit
+ *                unsigned int that is the number of bytes to be read.
+ *                To exit and output any fatal error messages the new write
+ *                function should call png_error(png_ptr, "Error msg").
+ *                May be NULL, in which case libpng's default function will
+ *                be used.
+ */
+void PNGAPI
+png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
+    png_rw_ptr read_data_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+   if (read_data_fn != NULL)
+      png_ptr->read_data_fn = read_data_fn;
+
+   else
+      png_ptr->read_data_fn = png_default_read_data;
+#else
+   png_ptr->read_data_fn = read_data_fn;
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   /* It is an error to write to a read device */
+   if (png_ptr->write_data_fn != NULL)
+   {
+      png_ptr->write_data_fn = NULL;
+      png_warning(png_ptr,
+          "Can't set both read_data_fn and write_data_fn in the"
+          " same structure");
+   }
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_ptr->output_flush_fn = NULL;
+#endif
+}
+#endif /* READ */
diff --git a/xs/src/png/libpng/pngrtran.c b/xs/src/png/libpng/pngrtran.c
new file mode 100644
index 000000000..c18965031
--- /dev/null
+++ b/xs/src/png/libpng/pngrtran.c
@@ -0,0 +1,5010 @@
+
+/* pngrtran.c - transforms the data in a row for PNG readers
+ *
+ * Last changed in libpng 1.6.33 [September 28, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains functions optionally called by an application
+ * in order to tell libpng how to handle data when reading a PNG.
+ * Transformations that are used in both reading and writing are
+ * in pngtrans.c.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */
+void PNGAPI
+png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
+{
+   png_debug(1, "in png_set_crc_action");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* Tell libpng how we react to CRC errors in critical chunks */
+   switch (crit_action)
+   {
+      case PNG_CRC_NO_CHANGE:                        /* Leave setting as is */
+         break;
+
+      case PNG_CRC_WARN_USE:                               /* Warn/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
+         break;
+
+      case PNG_CRC_QUIET_USE:                             /* Quiet/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
+                           PNG_FLAG_CRC_CRITICAL_IGNORE;
+         break;
+
+      case PNG_CRC_WARN_DISCARD:    /* Not a valid action for critical data */
+         png_warning(png_ptr,
+             "Can't discard critical data on CRC error");
+         /* FALLTHROUGH */
+      case PNG_CRC_ERROR_QUIT:                                /* Error/quit */
+
+      case PNG_CRC_DEFAULT:
+      default:
+         png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+         break;
+   }
+
+   /* Tell libpng how we react to CRC errors in ancillary chunks */
+   switch (ancil_action)
+   {
+      case PNG_CRC_NO_CHANGE:                       /* Leave setting as is */
+         break;
+
+      case PNG_CRC_WARN_USE:                              /* Warn/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
+         break;
+
+      case PNG_CRC_QUIET_USE:                            /* Quiet/use data */
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
+                           PNG_FLAG_CRC_ANCILLARY_NOWARN;
+         break;
+
+      case PNG_CRC_ERROR_QUIT:                               /* Error/quit */
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
+         break;
+
+      case PNG_CRC_WARN_DISCARD:                      /* Warn/discard data */
+
+      case PNG_CRC_DEFAULT:
+      default:
+         png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+         break;
+   }
+}
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Is it OK to set a transformation now?  Only if png_start_read_image or
+ * png_read_update_info have not been called.  It is not necessary for the IHDR
+ * to have been read in all cases; the need_IHDR parameter allows for this
+ * check too.
+ */
+static int
+png_rtran_ok(png_structrp png_ptr, int need_IHDR)
+{
+   if (png_ptr != NULL)
+   {
+      if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+         png_app_error(png_ptr,
+             "invalid after png_start_read_image or png_read_update_info");
+
+      else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
+         png_app_error(png_ptr, "invalid before the PNG header has been read");
+
+      else
+      {
+         /* Turn on failure to initialize correctly for all transforms. */
+         png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+
+         return 1; /* Ok */
+      }
+   }
+
+   return 0; /* no png_error possible! */
+}
+#endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+/* Handle alpha and tRNS via a background color */
+void PNGFAPI
+png_set_background_fixed(png_structrp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, png_fixed_point background_gamma)
+{
+   png_debug(1, "in png_set_background_fixed");
+
+   if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL)
+      return;
+
+   if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
+   {
+      png_warning(png_ptr, "Application must supply a known background gamma");
+      return;
+   }
+
+   png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
+   png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+   png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+   png_ptr->background = *background_color;
+   png_ptr->background_gamma = background_gamma;
+   png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
+   if (need_expand != 0)
+      png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
+   else
+      png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_background(png_structrp png_ptr,
+    png_const_color_16p background_color, int background_gamma_code,
+    int need_expand, double background_gamma)
+{
+   png_set_background_fixed(png_ptr, background_color, background_gamma_code,
+      need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
+}
+#  endif /* FLOATING_POINT */
+#endif /* READ_BACKGROUND */
+
+/* Scale 16-bit depth files to 8-bit depth.  If both of these are set then the
+ * one that pngrtran does first (scale) happens.  This is necessary to allow the
+ * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+void PNGAPI
+png_set_scale_16(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_scale_16");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= PNG_SCALE_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+/* Chop 16-bit depth files to 8-bit depth */
+void PNGAPI
+png_set_strip_16(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_strip_16");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= PNG_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+void PNGAPI
+png_set_strip_alpha(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_strip_alpha");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= PNG_STRIP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
+static png_fixed_point
+translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
+    int is_screen)
+{
+   /* Check for flag values.  The main reason for having the old Mac value as a
+    * flag is that it is pretty near impossible to work out what the correct
+    * value is from Apple documentation - a working Mac system is needed to
+    * discover the value!
+    */
+   if (output_gamma == PNG_DEFAULT_sRGB ||
+      output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
+   {
+      /* If there is no sRGB support this just sets the gamma to the standard
+       * sRGB value.  (This is a side effect of using this function!)
+       */
+#     ifdef PNG_READ_sRGB_SUPPORTED
+         png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
+#     else
+         PNG_UNUSED(png_ptr)
+#     endif
+      if (is_screen != 0)
+         output_gamma = PNG_GAMMA_sRGB;
+      else
+         output_gamma = PNG_GAMMA_sRGB_INVERSE;
+   }
+
+   else if (output_gamma == PNG_GAMMA_MAC_18 ||
+      output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
+   {
+      if (is_screen != 0)
+         output_gamma = PNG_GAMMA_MAC_OLD;
+      else
+         output_gamma = PNG_GAMMA_MAC_INVERSE;
+   }
+
+   return output_gamma;
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+static png_fixed_point
+convert_gamma_value(png_structrp png_ptr, double output_gamma)
+{
+   /* The following silently ignores cases where fixed point (times 100,000)
+    * gamma values are passed to the floating point API.  This is safe and it
+    * means the fixed point constants work just fine with the floating point
+    * API.  The alternative would just lead to undetected errors and spurious
+    * bug reports.  Negative values fail inside the _fixed API unless they
+    * correspond to the flag values.
+    */
+   if (output_gamma > 0 && output_gamma < 128)
+      output_gamma *= PNG_FP_1;
+
+   /* This preserves -1 and -2 exactly: */
+   output_gamma = floor(output_gamma + .5);
+
+   if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
+      png_fixed_error(png_ptr, "gamma value");
+
+   return (png_fixed_point)output_gamma;
+}
+#  endif
+#endif /* READ_ALPHA_MODE || READ_GAMMA */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+void PNGFAPI
+png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
+    png_fixed_point output_gamma)
+{
+   int compose = 0;
+   png_fixed_point file_gamma;
+
+   png_debug(1, "in png_set_alpha_mode");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
+
+   /* Validate the value to ensure it is in a reasonable range. The value
+    * is expected to be 1 or greater, but this range test allows for some
+    * viewing correction values.  The intent is to weed out users of this API
+    * who use the inverse of the gamma value accidentally!  Since some of these
+    * values are reasonable this may have to be changed:
+    *
+    * 1.6.x: changed from 0.07..3 to 0.01..100 (to accomodate the optimal 16-bit
+    * gamma of 36, and its reciprocal.)
+    */
+   if (output_gamma < 1000 || output_gamma > 10000000)
+      png_error(png_ptr, "output gamma out of expected range");
+
+   /* The default file gamma is the inverse of the output gamma; the output
+    * gamma may be changed below so get the file value first:
+    */
+   file_gamma = png_reciprocal(output_gamma);
+
+   /* There are really 8 possibilities here, composed of any combination
+    * of:
+    *
+    *    premultiply the color channels
+    *    do not encode non-opaque pixels
+    *    encode the alpha as well as the color channels
+    *
+    * The differences disappear if the input/output ('screen') gamma is 1.0,
+    * because then the encoding is a no-op and there is only the choice of
+    * premultiplying the color channels or not.
+    *
+    * png_set_alpha_mode and png_set_background interact because both use
+    * png_compose to do the work.  Calling both is only useful when
+    * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
+    * with a default gamma value.  Otherwise PNG_COMPOSE must not be set.
+    */
+   switch (mode)
+   {
+      case PNG_ALPHA_PNG:        /* default: png standard */
+         /* No compose, but it may be set by png_set_background! */
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         break;
+
+      case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
+         compose = 1;
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         /* The output is linear: */
+         output_gamma = PNG_FP_1;
+         break;
+
+      case PNG_ALPHA_OPTIMIZED:  /* associated, non-opaque pixels linear */
+         compose = 1;
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
+         /* output_gamma records the encoding of opaque pixels! */
+         break;
+
+      case PNG_ALPHA_BROKEN:     /* associated, non-linear, alpha encoded */
+         compose = 1;
+         png_ptr->transformations |= PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         break;
+
+      default:
+         png_error(png_ptr, "invalid alpha mode");
+   }
+
+   /* Only set the default gamma if the file gamma has not been set (this has
+    * the side effect that the gamma in a second call to png_set_alpha_mode will
+    * be ignored.)
+    */
+   if (png_ptr->colorspace.gamma == 0)
+   {
+      png_ptr->colorspace.gamma = file_gamma;
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+   }
+
+   /* But always set the output gamma: */
+   png_ptr->screen_gamma = output_gamma;
+
+   /* Finally, if pre-multiplying, set the background fields to achieve the
+    * desired result.
+    */
+   if (compose != 0)
+   {
+      /* And obtain alpha pre-multiplication by composing on black: */
+      memset(&png_ptr->background, 0, (sizeof png_ptr->background));
+      png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
+      png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
+      png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+
+      if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+         png_error(png_ptr,
+             "conflicting calls to set alpha mode and background");
+
+      png_ptr->transformations |= PNG_COMPOSE;
+   }
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
+{
+   png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
+       output_gamma));
+}
+#  endif
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Dither file to 8-bit.  Supply a palette, the current number
+ * of elements in the palette, the maximum number of elements
+ * allowed, and a histogram if possible.  If the current number
+ * of colors is greater than the maximum number, the palette will be
+ * modified to fit in the maximum number.  "full_quantize" indicates
+ * whether we need a quantizing cube set up for RGB images, or if we
+ * simply are reducing the number of colors in a paletted image.
+ */
+
+typedef struct png_dsort_struct
+{
+   struct png_dsort_struct * next;
+   png_byte left;
+   png_byte right;
+} png_dsort;
+typedef png_dsort *   png_dsortp;
+typedef png_dsort * * png_dsortpp;
+
+void PNGAPI
+png_set_quantize(png_structrp png_ptr, png_colorp palette,
+    int num_palette, int maximum_colors, png_const_uint_16p histogram,
+    int full_quantize)
+{
+   png_debug(1, "in png_set_quantize");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= PNG_QUANTIZE;
+
+   if (full_quantize == 0)
+   {
+      int i;
+
+      png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
+          (png_alloc_size_t)((png_uint_32)num_palette * (sizeof (png_byte))));
+      for (i = 0; i < num_palette; i++)
+         png_ptr->quantize_index[i] = (png_byte)i;
+   }
+
+   if (num_palette > maximum_colors)
+   {
+      if (histogram != NULL)
+      {
+         /* This is easy enough, just throw out the least used colors.
+          * Perhaps not the best solution, but good enough.
+          */
+
+         int i;
+
+         /* Initialize an array to sort colors */
+         png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
+             (png_alloc_size_t)((png_uint_32)num_palette * (sizeof (png_byte))));
+
+         /* Initialize the quantize_sort array */
+         for (i = 0; i < num_palette; i++)
+            png_ptr->quantize_sort[i] = (png_byte)i;
+
+         /* Find the least used palette entries by starting a
+          * bubble sort, and running it until we have sorted
+          * out enough colors.  Note that we don't care about
+          * sorting all the colors, just finding which are
+          * least used.
+          */
+
+         for (i = num_palette - 1; i >= maximum_colors; i--)
+         {
+            int done; /* To stop early if the list is pre-sorted */
+            int j;
+
+            done = 1;
+            for (j = 0; j < i; j++)
+            {
+               if (histogram[png_ptr->quantize_sort[j]]
+                   < histogram[png_ptr->quantize_sort[j + 1]])
+               {
+                  png_byte t;
+
+                  t = png_ptr->quantize_sort[j];
+                  png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+                  png_ptr->quantize_sort[j + 1] = t;
+                  done = 0;
+               }
+            }
+
+            if (done != 0)
+               break;
+         }
+
+         /* Swap the palette around, and set up a table, if necessary */
+         if (full_quantize != 0)
+         {
+            int j = num_palette;
+
+            /* Put all the useful colors within the max, but don't
+             * move the others.
+             */
+            for (i = 0; i < maximum_colors; i++)
+            {
+               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+               {
+                  do
+                     j--;
+                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+                  palette[i] = palette[j];
+               }
+            }
+         }
+         else
+         {
+            int j = num_palette;
+
+            /* Move all the used colors inside the max limit, and
+             * develop a translation table.
+             */
+            for (i = 0; i < maximum_colors; i++)
+            {
+               /* Only move the colors we need to */
+               if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
+               {
+                  png_color tmp_color;
+
+                  do
+                     j--;
+                  while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
+
+                  tmp_color = palette[j];
+                  palette[j] = palette[i];
+                  palette[i] = tmp_color;
+                  /* Indicate where the color went */
+                  png_ptr->quantize_index[j] = (png_byte)i;
+                  png_ptr->quantize_index[i] = (png_byte)j;
+               }
+            }
+
+            /* Find closest color for those colors we are not using */
+            for (i = 0; i < num_palette; i++)
+            {
+               if ((int)png_ptr->quantize_index[i] >= maximum_colors)
+               {
+                  int min_d, k, min_k, d_index;
+
+                  /* Find the closest color to one we threw out */
+                  d_index = png_ptr->quantize_index[i];
+                  min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
+                  for (k = 1, min_k = 0; k < maximum_colors; k++)
+                  {
+                     int d;
+
+                     d = PNG_COLOR_DIST(palette[d_index], palette[k]);
+
+                     if (d < min_d)
+                     {
+                        min_d = d;
+                        min_k = k;
+                     }
+                  }
+                  /* Point to closest color */
+                  png_ptr->quantize_index[i] = (png_byte)min_k;
+               }
+            }
+         }
+         png_free(png_ptr, png_ptr->quantize_sort);
+         png_ptr->quantize_sort = NULL;
+      }
+      else
+      {
+         /* This is much harder to do simply (and quickly).  Perhaps
+          * we need to go through a median cut routine, but those
+          * don't always behave themselves with only a few colors
+          * as input.  So we will just find the closest two colors,
+          * and throw out one of them (chosen somewhat randomly).
+          * [We don't understand this at all, so if someone wants to
+          *  work on improving it, be our guest - AED, GRP]
+          */
+         int i;
+         int max_d;
+         int num_new_palette;
+         png_dsortp t;
+         png_dsortpp hash;
+
+         t = NULL;
+
+         /* Initialize palette index arrays */
+         png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
+             (png_alloc_size_t)((png_uint_32)num_palette *
+             (sizeof (png_byte))));
+         png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
+             (png_alloc_size_t)((png_uint_32)num_palette *
+             (sizeof (png_byte))));
+
+         /* Initialize the sort array */
+         for (i = 0; i < num_palette; i++)
+         {
+            png_ptr->index_to_palette[i] = (png_byte)i;
+            png_ptr->palette_to_index[i] = (png_byte)i;
+         }
+
+         hash = (png_dsortpp)png_calloc(png_ptr, (png_alloc_size_t)(769 *
+             (sizeof (png_dsortp))));
+
+         num_new_palette = num_palette;
+
+         /* Initial wild guess at how far apart the farthest pixel
+          * pair we will be eliminating will be.  Larger
+          * numbers mean more areas will be allocated, Smaller
+          * numbers run the risk of not saving enough data, and
+          * having to do this all over again.
+          *
+          * I have not done extensive checking on this number.
+          */
+         max_d = 96;
+
+         while (num_new_palette > maximum_colors)
+         {
+            for (i = 0; i < num_new_palette - 1; i++)
+            {
+               int j;
+
+               for (j = i + 1; j < num_new_palette; j++)
+               {
+                  int d;
+
+                  d = PNG_COLOR_DIST(palette[i], palette[j]);
+
+                  if (d <= max_d)
+                  {
+
+                     t = (png_dsortp)png_malloc_warn(png_ptr,
+                         (png_alloc_size_t)(sizeof (png_dsort)));
+
+                     if (t == NULL)
+                         break;
+
+                     t->next = hash[d];
+                     t->left = (png_byte)i;
+                     t->right = (png_byte)j;
+                     hash[d] = t;
+                  }
+               }
+               if (t == NULL)
+                  break;
+            }
+
+            if (t != NULL)
+            for (i = 0; i <= max_d; i++)
+            {
+               if (hash[i] != NULL)
+               {
+                  png_dsortp p;
+
+                  for (p = hash[i]; p; p = p->next)
+                  {
+                     if ((int)png_ptr->index_to_palette[p->left]
+                         < num_new_palette &&
+                         (int)png_ptr->index_to_palette[p->right]
+                         < num_new_palette)
+                     {
+                        int j, next_j;
+
+                        if (num_new_palette & 0x01)
+                        {
+                           j = p->left;
+                           next_j = p->right;
+                        }
+                        else
+                        {
+                           j = p->right;
+                           next_j = p->left;
+                        }
+
+                        num_new_palette--;
+                        palette[png_ptr->index_to_palette[j]]
+                            = palette[num_new_palette];
+                        if (full_quantize == 0)
+                        {
+                           int k;
+
+                           for (k = 0; k < num_palette; k++)
+                           {
+                              if (png_ptr->quantize_index[k] ==
+                                  png_ptr->index_to_palette[j])
+                                 png_ptr->quantize_index[k] =
+                                     png_ptr->index_to_palette[next_j];
+
+                              if ((int)png_ptr->quantize_index[k] ==
+                                  num_new_palette)
+                                 png_ptr->quantize_index[k] =
+                                     png_ptr->index_to_palette[j];
+                           }
+                        }
+
+                        png_ptr->index_to_palette[png_ptr->palette_to_index
+                            [num_new_palette]] = png_ptr->index_to_palette[j];
+
+                        png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
+                            = png_ptr->palette_to_index[num_new_palette];
+
+                        png_ptr->index_to_palette[j] =
+                            (png_byte)num_new_palette;
+
+                        png_ptr->palette_to_index[num_new_palette] =
+                            (png_byte)j;
+                     }
+                     if (num_new_palette <= maximum_colors)
+                        break;
+                  }
+                  if (num_new_palette <= maximum_colors)
+                     break;
+               }
+            }
+
+            for (i = 0; i < 769; i++)
+            {
+               if (hash[i] != NULL)
+               {
+                  png_dsortp p = hash[i];
+                  while (p)
+                  {
+                     t = p->next;
+                     png_free(png_ptr, p);
+                     p = t;
+                  }
+               }
+               hash[i] = 0;
+            }
+            max_d += 96;
+         }
+         png_free(png_ptr, hash);
+         png_free(png_ptr, png_ptr->palette_to_index);
+         png_free(png_ptr, png_ptr->index_to_palette);
+         png_ptr->palette_to_index = NULL;
+         png_ptr->index_to_palette = NULL;
+      }
+      num_palette = maximum_colors;
+   }
+   if (png_ptr->palette == NULL)
+   {
+      png_ptr->palette = palette;
+   }
+   png_ptr->num_palette = (png_uint_16)num_palette;
+
+   if (full_quantize != 0)
+   {
+      int i;
+      png_bytep distance;
+      int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+          PNG_QUANTIZE_BLUE_BITS;
+      int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+      int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+      int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
+      png_size_t num_entries = ((png_size_t)1 << total_bits);
+
+      png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
+          (png_alloc_size_t)(num_entries * (sizeof (png_byte))));
+
+      distance = (png_bytep)png_malloc(png_ptr, (png_alloc_size_t)(num_entries *
+          (sizeof (png_byte))));
+
+      memset(distance, 0xff, num_entries * (sizeof (png_byte)));
+
+      for (i = 0; i < num_palette; i++)
+      {
+         int ir, ig, ib;
+         int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+         int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+         int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
+
+         for (ir = 0; ir < num_red; ir++)
+         {
+            /* int dr = abs(ir - r); */
+            int dr = ((ir > r) ? ir - r : r - ir);
+            int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+                PNG_QUANTIZE_GREEN_BITS));
+
+            for (ig = 0; ig < num_green; ig++)
+            {
+               /* int dg = abs(ig - g); */
+               int dg = ((ig > g) ? ig - g : g - ig);
+               int dt = dr + dg;
+               int dm = ((dr > dg) ? dr : dg);
+               int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
+
+               for (ib = 0; ib < num_blue; ib++)
+               {
+                  int d_index = index_g | ib;
+                  /* int db = abs(ib - b); */
+                  int db = ((ib > b) ? ib - b : b - ib);
+                  int dmax = ((dm > db) ? dm : db);
+                  int d = dmax + dt + db;
+
+                  if (d < (int)distance[d_index])
+                  {
+                     distance[d_index] = (png_byte)d;
+                     png_ptr->palette_lookup[d_index] = (png_byte)i;
+                  }
+               }
+            }
+         }
+      }
+
+      png_free(png_ptr, distance);
+   }
+}
+#endif /* READ_QUANTIZE */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+void PNGFAPI
+png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
+    png_fixed_point file_gamma)
+{
+   png_debug(1, "in png_set_gamma_fixed");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   /* New in libpng-1.5.4 - reserve particular negative values as flags. */
+   scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
+   file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
+
+   /* Checking the gamma values for being >0 was added in 1.5.4 along with the
+    * premultiplied alpha support; this actually hides an undocumented feature
+    * of the previous implementation which allowed gamma processing to be
+    * disabled in background handling.  There is no evidence (so far) that this
+    * was being used; however, png_set_background itself accepted and must still
+    * accept '0' for the gamma value it takes, because it isn't always used.
+    *
+    * Since this is an API change (albeit a very minor one that removes an
+    * undocumented API feature) the following checks were only enabled in
+    * libpng-1.6.0.
+    */
+   if (file_gamma <= 0)
+      png_error(png_ptr, "invalid file gamma in png_set_gamma");
+
+   if (scrn_gamma <= 0)
+      png_error(png_ptr, "invalid screen gamma in png_set_gamma");
+
+   /* Set the gamma values unconditionally - this overrides the value in the PNG
+    * file if a gAMA chunk was present.  png_set_alpha_mode provides a
+    * different, easier, way to default the file gamma.
+    */
+   png_ptr->colorspace.gamma = file_gamma;
+   png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+   png_ptr->screen_gamma = scrn_gamma;
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
+{
+   png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
+       convert_gamma_value(png_ptr, file_gamma));
+}
+#  endif /* FLOATING_POINT */
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
+ * to alpha channels.
+ */
+void PNGAPI
+png_set_expand(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_expand");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
+/* GRR 19990627:  the following three functions currently are identical
+ *  to png_set_expand().  However, it is entirely reasonable that someone
+ *  might wish to expand an indexed image to RGB but *not* expand a single,
+ *  fully transparent palette entry to a full alpha channel--perhaps instead
+ *  convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ *  the transparent color with a particular RGB value, or drop tRNS entirely.
+ *  IOW, a future version of the library may make the transformations flag
+ *  a bit more fine-grained, with separate bits for each of these three
+ *  functions.
+ *
+ *  More to the point, these functions make it obvious what libpng will be
+ *  doing, whereas "expand" can (and does) mean any number of things.
+ *
+ *  GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
+ *  to expand only the sample depth but not to expand the tRNS to alpha
+ *  and its name was changed to png_set_expand_gray_1_2_4_to_8().
+ */
+
+/* Expand paletted images to RGB. */
+void PNGAPI
+png_set_palette_to_rgb(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_palette_to_rgb");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void PNGAPI
+png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= PNG_EXPAND;
+}
+
+/* Expand tRNS chunks to alpha channels. */
+void PNGAPI
+png_set_tRNS_to_alpha(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_tRNS_to_alpha");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif /* READ_EXPAND */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
+ * it may not work correctly.)
+ */
+void PNGAPI
+png_set_expand_16(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_expand_16");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+void PNGAPI
+png_set_gray_to_rgb(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_gray_to_rgb");
+
+   if (png_rtran_ok(png_ptr, 0) == 0)
+      return;
+
+   /* Because rgb must be 8 bits or more: */
+   png_set_expand_gray_1_2_4_to_8(png_ptr);
+   png_ptr->transformations |= PNG_GRAY_TO_RGB;
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+void PNGFAPI
+png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
+    png_fixed_point red, png_fixed_point green)
+{
+   png_debug(1, "in png_set_rgb_to_gray");
+
+   /* Need the IHDR here because of the check on color_type below. */
+   /* TODO: fix this */
+   if (png_rtran_ok(png_ptr, 1) == 0)
+      return;
+
+   switch (error_action)
+   {
+      case PNG_ERROR_ACTION_NONE:
+         png_ptr->transformations |= PNG_RGB_TO_GRAY;
+         break;
+
+      case PNG_ERROR_ACTION_WARN:
+         png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+         break;
+
+      case PNG_ERROR_ACTION_ERROR:
+         png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+         break;
+
+      default:
+         png_error(png_ptr, "invalid error action to rgb_to_gray");
+   }
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#ifdef PNG_READ_EXPAND_SUPPORTED
+      png_ptr->transformations |= PNG_EXPAND;
+#else
+   {
+      /* Make this an error in 1.6 because otherwise the application may assume
+       * that it just worked and get a memory overwrite.
+       */
+      png_error(png_ptr,
+          "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
+
+      /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
+   }
+#endif
+   {
+      if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
+      {
+         png_uint_16 red_int, green_int;
+
+         /* NOTE: this calculation does not round, but this behavior is retained
+          * for consistency; the inaccuracy is very small.  The code here always
+          * overwrites the coefficients, regardless of whether they have been
+          * defaulted or set already.
+          */
+         red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
+         green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
+
+         png_ptr->rgb_to_gray_red_coeff   = red_int;
+         png_ptr->rgb_to_gray_green_coeff = green_int;
+         png_ptr->rgb_to_gray_coefficients_set = 1;
+      }
+
+      else
+      {
+         if (red >= 0 && green >= 0)
+            png_app_warning(png_ptr,
+                "ignoring out of range rgb_to_gray coefficients");
+
+         /* Use the defaults, from the cHRM chunk if set, else the historical
+          * values which are close to the sRGB/HDTV/ITU-Rec 709 values.  See
+          * png_do_rgb_to_gray for more discussion of the values.  In this case
+          * the coefficients are not marked as 'set' and are not overwritten if
+          * something has already provided a default.
+          */
+         if (png_ptr->rgb_to_gray_red_coeff == 0 &&
+             png_ptr->rgb_to_gray_green_coeff == 0)
+         {
+            png_ptr->rgb_to_gray_red_coeff   = 6968;
+            png_ptr->rgb_to_gray_green_coeff = 23434;
+            /* png_ptr->rgb_to_gray_blue_coeff  = 2366; */
+         }
+      }
+   }
+}
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+/* Convert a RGB image to a grayscale of the same width.  This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
+ */
+
+void PNGAPI
+png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
+    double green)
+{
+   png_set_rgb_to_gray_fixed(png_ptr, error_action,
+       png_fixed(png_ptr, red, "rgb to gray red coefficient"),
+      png_fixed(png_ptr, green, "rgb to gray green coefficient"));
+}
+#endif /* FLOATING POINT */
+
+#endif /* RGB_TO_GRAY */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void PNGAPI
+png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
+    read_user_transform_fn)
+{
+   png_debug(1, "in png_set_read_user_transform_fn");
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_ptr->transformations |= PNG_USER_TRANSFORM;
+   png_ptr->read_user_transform_fn = read_user_transform_fn;
+#endif
+}
+#endif
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* In the case of gamma transformations only do transformations on images where
+ * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
+ * slows things down slightly, and also needlessly introduces small errors.
+ */
+static int /* PRIVATE */
+png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
+{
+   /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
+    * correction as a difference of the overall transform from 1.0
+    *
+    * We want to compare the threshold with s*f - 1, if we get
+    * overflow here it is because of wacky gamma values so we
+    * turn on processing anyway.
+    */
+   png_fixed_point gtest;
+   return !png_muldiv(&gtest, screen_gamma, file_gamma, PNG_FP_1) ||
+       png_gamma_significant(gtest);
+}
+#endif
+
+/* Initialize everything needed for the read.  This includes modifying
+ * the palette.
+ */
+
+/* For the moment 'png_init_palette_transformations' and
+ * 'png_init_rgb_transformations' only do some flag canceling optimizations.
+ * The intent is that these two routines should have palette or rgb operations
+ * extracted from 'png_init_read_transformations'.
+ */
+static void /* PRIVATE */
+png_init_palette_transformations(png_structrp png_ptr)
+{
+   /* Called to handle the (input) palette case.  In png_do_read_transformations
+    * the first step is to expand the palette if requested, so this code must
+    * take care to only make changes that are invariant with respect to the
+    * palette expansion, or only do them if there is no expansion.
+    *
+    * STRIP_ALPHA has already been handled in the caller (by setting num_trans
+    * to 0.)
+    */
+   int input_has_alpha = 0;
+   int input_has_transparency = 0;
+
+   if (png_ptr->num_trans > 0)
+   {
+      int i;
+
+      /* Ignore if all the entries are opaque (unlikely!) */
+      for (i=0; i<png_ptr->num_trans; ++i)
+      {
+         if (png_ptr->trans_alpha[i] == 255)
+            continue;
+         else if (png_ptr->trans_alpha[i] == 0)
+            input_has_transparency = 1;
+         else
+         {
+            input_has_transparency = 1;
+            input_has_alpha = 1;
+            break;
+         }
+      }
+   }
+
+   /* If no alpha we can optimize. */
+   if (input_has_alpha == 0)
+   {
+      /* Any alpha means background and associative alpha processing is
+       * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
+       * and ENCODE_ALPHA are irrelevant.
+       */
+      png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+      if (input_has_transparency == 0)
+         png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+   }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* png_set_background handling - deals with the complexity of whether the
+    * background color is in the file format or the screen format in the case
+    * where an 'expand' will happen.
+    */
+
+   /* The following code cannot be entered in the alpha pre-multiplication case
+    * because PNG_BACKGROUND_EXPAND is cancelled below.
+    */
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+       (png_ptr->transformations & PNG_EXPAND) != 0)
+   {
+      {
+         png_ptr->background.red   =
+             png_ptr->palette[png_ptr->background.index].red;
+         png_ptr->background.green =
+             png_ptr->palette[png_ptr->background.index].green;
+         png_ptr->background.blue  =
+             png_ptr->palette[png_ptr->background.index].blue;
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+        if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+        {
+           if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
+           {
+              /* Invert the alpha channel (in tRNS) unless the pixels are
+               * going to be expanded, in which case leave it for later
+               */
+              int i, istop = png_ptr->num_trans;
+
+              for (i=0; i<istop; i++)
+                 png_ptr->trans_alpha[i] = (png_byte)(255 -
+                    png_ptr->trans_alpha[i]);
+           }
+        }
+#endif /* READ_INVERT_ALPHA */
+      }
+   } /* background expand and (therefore) no alpha association. */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+}
+
+static void /* PRIVATE */
+png_init_rgb_transformations(png_structrp png_ptr)
+{
+   /* Added to libpng-1.5.4: check the color type to determine whether there
+    * is any alpha or transparency in the image and simply cancel the
+    * background and alpha mode stuff if there isn't.
+    */
+   int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+   int input_has_transparency = png_ptr->num_trans > 0;
+
+   /* If no alpha we can optimize. */
+   if (input_has_alpha == 0)
+   {
+      /* Any alpha means background and associative alpha processing is
+       * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
+       * and ENCODE_ALPHA are irrelevant.
+       */
+#     ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+#     endif
+
+      if (input_has_transparency == 0)
+         png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+   }
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* png_set_background handling - deals with the complexity of whether the
+    * background color is in the file format or the screen format in the case
+    * where an 'expand' will happen.
+    */
+
+   /* The following code cannot be entered in the alpha pre-multiplication case
+    * because PNG_BACKGROUND_EXPAND is cancelled below.
+    */
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+       (png_ptr->transformations & PNG_EXPAND) != 0 &&
+       (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+       /* i.e., GRAY or GRAY_ALPHA */
+   {
+      {
+         /* Expand background and tRNS chunks */
+         int gray = png_ptr->background.gray;
+         int trans_gray = png_ptr->trans_color.gray;
+
+         switch (png_ptr->bit_depth)
+         {
+            case 1:
+               gray *= 0xff;
+               trans_gray *= 0xff;
+               break;
+
+            case 2:
+               gray *= 0x55;
+               trans_gray *= 0x55;
+               break;
+
+            case 4:
+               gray *= 0x11;
+               trans_gray *= 0x11;
+               break;
+
+            default:
+
+            case 8:
+               /* FALLTHROUGH */ /*  (Already 8 bits) */
+
+            case 16:
+               /* Already a full 16 bits */
+               break;
+         }
+
+         png_ptr->background.red = png_ptr->background.green =
+            png_ptr->background.blue = (png_uint_16)gray;
+
+         if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
+         {
+            png_ptr->trans_color.red = png_ptr->trans_color.green =
+               png_ptr->trans_color.blue = (png_uint_16)trans_gray;
+         }
+      }
+   } /* background expand and (therefore) no alpha association. */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+}
+
+void /* PRIVATE */
+png_init_read_transformations(png_structrp png_ptr)
+{
+   png_debug(1, "in png_init_read_transformations");
+
+   /* This internal function is called from png_read_start_row in pngrutil.c
+    * and it is called before the 'rowbytes' calculation is done, so the code
+    * in here can change or update the transformations flags.
+    *
+    * First do updates that do not depend on the details of the PNG image data
+    * being processed.
+    */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
+    * png_set_alpha_mode and this is another source for a default file gamma so
+    * the test needs to be performed later - here.  In addition prior to 1.5.4
+    * the tests were repeated for the PALETTE color type here - this is no
+    * longer necessary (and doesn't seem to have been necessary before.)
+    */
+   {
+      /* The following temporary indicates if overall gamma correction is
+       * required.
+       */
+      int gamma_correction = 0;
+
+      if (png_ptr->colorspace.gamma != 0) /* has been set */
+      {
+         if (png_ptr->screen_gamma != 0) /* screen set too */
+            gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma,
+                png_ptr->screen_gamma);
+
+         else
+            /* Assume the output matches the input; a long time default behavior
+             * of libpng, although the standard has nothing to say about this.
+             */
+            png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma);
+      }
+
+      else if (png_ptr->screen_gamma != 0)
+         /* The converse - assume the file matches the screen, note that this
+          * perhaps undesireable default can (from 1.5.4) be changed by calling
+          * png_set_alpha_mode (even if the alpha handling mode isn't required
+          * or isn't changed from the default.)
+          */
+         png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma);
+
+      else /* neither are set */
+         /* Just in case the following prevents any processing - file and screen
+          * are both assumed to be linear and there is no way to introduce a
+          * third gamma value other than png_set_background with 'UNIQUE', and,
+          * prior to 1.5.4
+          */
+         png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1;
+
+      /* We have a gamma value now. */
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+
+      /* Now turn the gamma transformation on or off as appropriate.  Notice
+       * that PNG_GAMMA just refers to the file->screen correction.  Alpha
+       * composition may independently cause gamma correction because it needs
+       * linear data (e.g. if the file has a gAMA chunk but the screen gamma
+       * hasn't been specified.)  In any case this flag may get turned off in
+       * the code immediately below if the transform can be handled outside the
+       * row loop.
+       */
+      if (gamma_correction != 0)
+         png_ptr->transformations |= PNG_GAMMA;
+
+      else
+         png_ptr->transformations &= ~PNG_GAMMA;
+   }
+#endif
+
+   /* Certain transformations have the effect of preventing other
+    * transformations that happen afterward in png_do_read_transformations;
+    * resolve the interdependencies here.  From the code of
+    * png_do_read_transformations the order is:
+    *
+    *  1) PNG_EXPAND (including PNG_EXPAND_tRNS)
+    *  2) PNG_STRIP_ALPHA (if no compose)
+    *  3) PNG_RGB_TO_GRAY
+    *  4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
+    *  5) PNG_COMPOSE
+    *  6) PNG_GAMMA
+    *  7) PNG_STRIP_ALPHA (if compose)
+    *  8) PNG_ENCODE_ALPHA
+    *  9) PNG_SCALE_16_TO_8
+    * 10) PNG_16_TO_8
+    * 11) PNG_QUANTIZE (converts to palette)
+    * 12) PNG_EXPAND_16
+    * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
+    * 14) PNG_INVERT_MONO
+    * 15) PNG_INVERT_ALPHA
+    * 16) PNG_SHIFT
+    * 17) PNG_PACK
+    * 18) PNG_BGR
+    * 19) PNG_PACKSWAP
+    * 20) PNG_FILLER (includes PNG_ADD_ALPHA)
+    * 21) PNG_SWAP_ALPHA
+    * 22) PNG_SWAP_BYTES
+    * 23) PNG_USER_TRANSFORM [must be last]
+    */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) == 0)
+   {
+      /* Stripping the alpha channel happens immediately after the 'expand'
+       * transformations, before all other transformation, so it cancels out
+       * the alpha handling.  It has the side effect negating the effect of
+       * PNG_EXPAND_tRNS too:
+       */
+      png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
+         PNG_EXPAND_tRNS);
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+      /* Kill the tRNS chunk itself too.  Prior to 1.5.4 this did not happen
+       * so transparency information would remain just so long as it wasn't
+       * expanded.  This produces unexpected API changes if the set of things
+       * that do PNG_EXPAND_tRNS changes (perfectly possible given the
+       * documentation - which says ask for what you want, accept what you
+       * get.)  This makes the behavior consistent from 1.5.4:
+       */
+      png_ptr->num_trans = 0;
+   }
+#endif /* STRIP_ALPHA supported, no COMPOSE */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
+    * settings will have no effect.
+    */
+   if (png_gamma_significant(png_ptr->screen_gamma) == 0)
+   {
+      png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+   }
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   /* Make sure the coefficients for the rgb to gray conversion are set
+    * appropriately.
+    */
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+      png_colorspace_set_rgb_coefficients(png_ptr);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* Detect gray background and attempt to enable optimization for
+    * gray --> RGB case.
+    *
+    * Note:  if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+    * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+    * background color might actually be gray yet not be flagged as such.
+    * This is not a problem for the current code, which uses
+    * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+    * png_do_gray_to_rgb() transformation.
+    *
+    * TODO: this code needs to be revised to avoid the complexity and
+    * interdependencies.  The color type of the background should be recorded in
+    * png_set_background, along with the bit depth, then the code has a record
+    * of exactly what color space the background is currently in.
+    */
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0)
+   {
+      /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
+       * the file was grayscale the background value is gray.
+       */
+      if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+         png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+   }
+
+   else if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+   {
+      /* PNG_COMPOSE: png_set_background was called with need_expand false,
+       * so the color is in the color space of the output or png_set_alpha_mode
+       * was called and the color is black.  Ignore RGB_TO_GRAY because that
+       * happens before GRAY_TO_RGB.
+       */
+      if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+      {
+         if (png_ptr->background.red == png_ptr->background.green &&
+             png_ptr->background.red == png_ptr->background.blue)
+         {
+            png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+            png_ptr->background.gray = png_ptr->background.red;
+         }
+      }
+   }
+#endif /* READ_EXPAND && READ_BACKGROUND */
+#endif /* READ_GRAY_TO_RGB */
+
+   /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
+    * can be performed directly on the palette, and some (such as rgb to gray)
+    * can be optimized inside the palette.  This is particularly true of the
+    * composite (background and alpha) stuff, which can be pretty much all done
+    * in the palette even if the result is expanded to RGB or gray afterward.
+    *
+    * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
+    * earlier and the palette stuff is actually handled on the first row.  This
+    * leads to the reported bug that the palette returned by png_get_PLTE is not
+    * updated.
+    */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      png_init_palette_transformations(png_ptr);
+
+   else
+      png_init_rgb_transformations(png_ptr);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   defined(PNG_READ_EXPAND_16_SUPPORTED)
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+       png_ptr->bit_depth != 16)
+   {
+      /* TODO: fix this.  Because the expand_16 operation is after the compose
+       * handling the background color must be 8, not 16, bits deep, but the
+       * application will supply a 16-bit value so reduce it here.
+       *
+       * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
+       * present, so that case is ok (until do_expand_16 is moved.)
+       *
+       * NOTE: this discards the low 16 bits of the user supplied background
+       * color, but until expand_16 works properly there is no choice!
+       */
+#     define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
+      CHOP(png_ptr->background.red);
+      CHOP(png_ptr->background.green);
+      CHOP(png_ptr->background.blue);
+      CHOP(png_ptr->background.gray);
+#     undef CHOP
+   }
+#endif /* READ_BACKGROUND && READ_EXPAND_16 */
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
+   defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
+   if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+       png_ptr->bit_depth == 16)
+   {
+      /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
+       * component this will also happen after PNG_COMPOSE and so the background
+       * color must be pre-expanded here.
+       *
+       * TODO: fix this too.
+       */
+      png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
+      png_ptr->background.green =
+         (png_uint_16)(png_ptr->background.green * 257);
+      png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
+      png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
+   }
+#endif
+
+   /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
+    * background support (see the comments in scripts/pnglibconf.dfa), this
+    * allows pre-multiplication of the alpha channel to be implemented as
+    * compositing on black.  This is probably sub-optimal and has been done in
+    * 1.5.4 betas simply to enable external critique and testing (i.e. to
+    * implement the new API quickly, without lots of internal changes.)
+    */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+      /* Includes ALPHA_MODE */
+      png_ptr->background_1 = png_ptr->background;
+#  endif
+
+   /* This needs to change - in the palette image case a whole set of tables are
+    * built when it would be quicker to just calculate the correct value for
+    * each palette entry directly.  Also, the test is too tricky - why check
+    * PNG_RGB_TO_GRAY if PNG_GAMMA is not set?  The answer seems to be that
+    * PNG_GAMMA is cancelled even if the gamma is known?  The test excludes the
+    * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
+    * the gamma tables will not be built even if composition is required on a
+    * gamma encoded value.
+    *
+    * In 1.5.4 this is addressed below by an additional check on the individual
+    * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
+    * tables.
+    */
+   if ((png_ptr->transformations & PNG_GAMMA) != 0 ||
+       ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 &&
+        (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
+         png_gamma_significant(png_ptr->screen_gamma) != 0)) ||
+        ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+         (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
+          png_gamma_significant(png_ptr->screen_gamma) != 0
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+         || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE &&
+           png_gamma_significant(png_ptr->background_gamma) != 0)
+#  endif
+        )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+       png_gamma_significant(png_ptr->screen_gamma) != 0))
+   {
+      png_build_gamma_table(png_ptr, png_ptr->bit_depth);
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+      if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+      {
+         /* Issue a warning about this combination: because RGB_TO_GRAY is
+          * optimized to do the gamma transform if present yet do_background has
+          * to do the same thing if both options are set a
+          * double-gamma-correction happens.  This is true in all versions of
+          * libpng to date.
+          */
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+            png_warning(png_ptr,
+                "libpng does not support gamma+background+rgb_to_gray");
+
+         if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0)
+         {
+            /* We don't get to here unless there is a tRNS chunk with non-opaque
+             * entries - see the checking code at the start of this function.
+             */
+            png_color back, back_1;
+            png_colorp palette = png_ptr->palette;
+            int num_palette = png_ptr->num_palette;
+            int i;
+            if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+            {
+
+               back.red = png_ptr->gamma_table[png_ptr->background.red];
+               back.green = png_ptr->gamma_table[png_ptr->background.green];
+               back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+
+               back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+               back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+               back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+            }
+            else
+            {
+               png_fixed_point g, gs;
+
+               switch (png_ptr->background_gamma_type)
+               {
+                  case PNG_BACKGROUND_GAMMA_SCREEN:
+                     g = (png_ptr->screen_gamma);
+                     gs = PNG_FP_1;
+                     break;
+
+                  case PNG_BACKGROUND_GAMMA_FILE:
+                     g = png_reciprocal(png_ptr->colorspace.gamma);
+                     gs = png_reciprocal2(png_ptr->colorspace.gamma,
+                         png_ptr->screen_gamma);
+                     break;
+
+                  case PNG_BACKGROUND_GAMMA_UNIQUE:
+                     g = png_reciprocal(png_ptr->background_gamma);
+                     gs = png_reciprocal2(png_ptr->background_gamma,
+                         png_ptr->screen_gamma);
+                     break;
+                  default:
+                     g = PNG_FP_1;    /* back_1 */
+                     gs = PNG_FP_1;   /* back */
+                     break;
+               }
+
+               if (png_gamma_significant(gs) != 0)
+               {
+                  back.red = png_gamma_8bit_correct(png_ptr->background.red,
+                      gs);
+                  back.green = png_gamma_8bit_correct(png_ptr->background.green,
+                      gs);
+                  back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+                      gs);
+               }
+
+               else
+               {
+                  back.red   = (png_byte)png_ptr->background.red;
+                  back.green = (png_byte)png_ptr->background.green;
+                  back.blue  = (png_byte)png_ptr->background.blue;
+               }
+
+               if (png_gamma_significant(g) != 0)
+               {
+                  back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
+                      g);
+                  back_1.green = png_gamma_8bit_correct(
+                      png_ptr->background.green, g);
+                  back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+                      g);
+               }
+
+               else
+               {
+                  back_1.red   = (png_byte)png_ptr->background.red;
+                  back_1.green = (png_byte)png_ptr->background.green;
+                  back_1.blue  = (png_byte)png_ptr->background.blue;
+               }
+            }
+
+            for (i = 0; i < num_palette; i++)
+            {
+               if (i < (int)png_ptr->num_trans &&
+                   png_ptr->trans_alpha[i] != 0xff)
+               {
+                  if (png_ptr->trans_alpha[i] == 0)
+                  {
+                     palette[i] = back;
+                  }
+                  else /* if (png_ptr->trans_alpha[i] != 0xff) */
+                  {
+                     png_byte v, w;
+
+                     v = png_ptr->gamma_to_1[palette[i].red];
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
+                     palette[i].red = png_ptr->gamma_from_1[w];
+
+                     v = png_ptr->gamma_to_1[palette[i].green];
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
+                     palette[i].green = png_ptr->gamma_from_1[w];
+
+                     v = png_ptr->gamma_to_1[palette[i].blue];
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
+                     palette[i].blue = png_ptr->gamma_from_1[w];
+                  }
+               }
+               else
+               {
+                  palette[i].red = png_ptr->gamma_table[palette[i].red];
+                  palette[i].green = png_ptr->gamma_table[palette[i].green];
+                  palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+               }
+            }
+
+            /* Prevent the transformations being done again.
+             *
+             * NOTE: this is highly dubious; it removes the transformations in
+             * place.  This seems inconsistent with the general treatment of the
+             * transformations elsewhere.
+             */
+            png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
+         } /* color_type == PNG_COLOR_TYPE_PALETTE */
+
+         /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
+         else /* color_type != PNG_COLOR_TYPE_PALETTE */
+         {
+            int gs_sig, g_sig;
+            png_fixed_point g = PNG_FP_1;  /* Correction to linear */
+            png_fixed_point gs = PNG_FP_1; /* Correction to screen */
+
+            switch (png_ptr->background_gamma_type)
+            {
+               case PNG_BACKGROUND_GAMMA_SCREEN:
+                  g = png_ptr->screen_gamma;
+                  /* gs = PNG_FP_1; */
+                  break;
+
+               case PNG_BACKGROUND_GAMMA_FILE:
+                  g = png_reciprocal(png_ptr->colorspace.gamma);
+                  gs = png_reciprocal2(png_ptr->colorspace.gamma,
+                      png_ptr->screen_gamma);
+                  break;
+
+               case PNG_BACKGROUND_GAMMA_UNIQUE:
+                  g = png_reciprocal(png_ptr->background_gamma);
+                  gs = png_reciprocal2(png_ptr->background_gamma,
+                      png_ptr->screen_gamma);
+                  break;
+
+               default:
+                  png_error(png_ptr, "invalid background gamma type");
+            }
+
+            g_sig = png_gamma_significant(g);
+            gs_sig = png_gamma_significant(gs);
+
+            if (g_sig != 0)
+               png_ptr->background_1.gray = png_gamma_correct(png_ptr,
+                   png_ptr->background.gray, g);
+
+            if (gs_sig != 0)
+               png_ptr->background.gray = png_gamma_correct(png_ptr,
+                   png_ptr->background.gray, gs);
+
+            if ((png_ptr->background.red != png_ptr->background.green) ||
+                (png_ptr->background.red != png_ptr->background.blue) ||
+                (png_ptr->background.red != png_ptr->background.gray))
+            {
+               /* RGB or RGBA with color background */
+               if (g_sig != 0)
+               {
+                  png_ptr->background_1.red = png_gamma_correct(png_ptr,
+                      png_ptr->background.red, g);
+
+                  png_ptr->background_1.green = png_gamma_correct(png_ptr,
+                      png_ptr->background.green, g);
+
+                  png_ptr->background_1.blue = png_gamma_correct(png_ptr,
+                      png_ptr->background.blue, g);
+               }
+
+               if (gs_sig != 0)
+               {
+                  png_ptr->background.red = png_gamma_correct(png_ptr,
+                      png_ptr->background.red, gs);
+
+                  png_ptr->background.green = png_gamma_correct(png_ptr,
+                      png_ptr->background.green, gs);
+
+                  png_ptr->background.blue = png_gamma_correct(png_ptr,
+                      png_ptr->background.blue, gs);
+               }
+            }
+
+            else
+            {
+               /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
+               png_ptr->background_1.red = png_ptr->background_1.green
+                   = png_ptr->background_1.blue = png_ptr->background_1.gray;
+
+               png_ptr->background.red = png_ptr->background.green
+                   = png_ptr->background.blue = png_ptr->background.gray;
+            }
+
+            /* The background is now in screen gamma: */
+            png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
+         } /* color_type != PNG_COLOR_TYPE_PALETTE */
+      }/* png_ptr->transformations & PNG_BACKGROUND */
+
+      else
+      /* Transformation does not include PNG_BACKGROUND */
+#endif /* READ_BACKGROUND */
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+         /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
+         && ((png_ptr->transformations & PNG_EXPAND) == 0 ||
+         (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+#endif
+         )
+      {
+         png_colorp palette = png_ptr->palette;
+         int num_palette = png_ptr->num_palette;
+         int i;
+
+         /* NOTE: there are other transformations that should probably be in
+          * here too.
+          */
+         for (i = 0; i < num_palette; i++)
+         {
+            palette[i].red = png_ptr->gamma_table[palette[i].red];
+            palette[i].green = png_ptr->gamma_table[palette[i].green];
+            palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+         }
+
+         /* Done the gamma correction. */
+         png_ptr->transformations &= ~PNG_GAMMA;
+      } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
+   }
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+   else
+#endif
+#endif /* READ_GAMMA */
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+   /* No GAMMA transformation (see the hanging else 4 lines above) */
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+   {
+      int i;
+      int istop = (int)png_ptr->num_trans;
+      png_color back;
+      png_colorp palette = png_ptr->palette;
+
+      back.red   = (png_byte)png_ptr->background.red;
+      back.green = (png_byte)png_ptr->background.green;
+      back.blue  = (png_byte)png_ptr->background.blue;
+
+      for (i = 0; i < istop; i++)
+      {
+         if (png_ptr->trans_alpha[i] == 0)
+         {
+            palette[i] = back;
+         }
+
+         else if (png_ptr->trans_alpha[i] != 0xff)
+         {
+            /* The png_composite() macro is defined in png.h */
+            png_composite(palette[i].red, palette[i].red,
+                png_ptr->trans_alpha[i], back.red);
+
+            png_composite(palette[i].green, palette[i].green,
+                png_ptr->trans_alpha[i], back.green);
+
+            png_composite(palette[i].blue, palette[i].blue,
+                png_ptr->trans_alpha[i], back.blue);
+         }
+      }
+
+      png_ptr->transformations &= ~PNG_COMPOSE;
+   }
+#endif /* READ_BACKGROUND */
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SHIFT) != 0 &&
+       (png_ptr->transformations & PNG_EXPAND) == 0 &&
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+   {
+      int i;
+      int istop = png_ptr->num_palette;
+      int shift = 8 - png_ptr->sig_bit.red;
+
+      png_ptr->transformations &= ~PNG_SHIFT;
+
+      /* significant bits can be in the range 1 to 7 for a meaninful result, if
+       * the number of significant bits is 0 then no shift is done (this is an
+       * error condition which is silently ignored.)
+       */
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].red;
+
+            component >>= shift;
+            png_ptr->palette[i].red = (png_byte)component;
+         }
+
+      shift = 8 - png_ptr->sig_bit.green;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].green;
+
+            component >>= shift;
+            png_ptr->palette[i].green = (png_byte)component;
+         }
+
+      shift = 8 - png_ptr->sig_bit.blue;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].blue;
+
+            component >>= shift;
+            png_ptr->palette[i].blue = (png_byte)component;
+         }
+   }
+#endif /* READ_SHIFT */
+}
+
+/* Modify the info structure to reflect the transformations.  The
+ * info should be updated so a PNG file could be written with it,
+ * assuming the transformations result in valid PNG data.
+ */
+void /* PRIVATE */
+png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
+{
+   png_debug(1, "in png_read_transform_info");
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   if ((png_ptr->transformations & PNG_EXPAND) != 0)
+   {
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         /* This check must match what actually happens in
+          * png_do_expand_palette; if it ever checks the tRNS chunk to see if
+          * it is all opaque we must do the same (at present it does not.)
+          */
+         if (png_ptr->num_trans > 0)
+            info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+
+         else
+            info_ptr->color_type = PNG_COLOR_TYPE_RGB;
+
+         info_ptr->bit_depth = 8;
+         info_ptr->num_trans = 0;
+
+         if (png_ptr->palette == NULL)
+            png_error (png_ptr, "Palette is NULL in indexed image");
+      }
+      else
+      {
+         if (png_ptr->num_trans != 0)
+         {
+            if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
+               info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+         }
+         if (info_ptr->bit_depth < 8)
+            info_ptr->bit_depth = 8;
+
+         info_ptr->num_trans = 0;
+      }
+   }
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   /* The following is almost certainly wrong unless the background value is in
+    * the screen space!
+    */
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+      info_ptr->background = png_ptr->background;
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
+    * however it seems that the code in png_init_read_transformations, which has
+    * been called before this from png_read_update_info->png_read_start_row
+    * sometimes does the gamma transform and cancels the flag.
+    *
+    * TODO: this looks wrong; the info_ptr should end up with a gamma equal to
+    * the screen_gamma value.  The following probably results in weirdness if
+    * the info_ptr is used by the app after the rows have been read.
+    */
+   info_ptr->colorspace.gamma = png_ptr->colorspace.gamma;
+#endif
+
+   if (info_ptr->bit_depth == 16)
+   {
+#  ifdef PNG_READ_16BIT_SUPPORTED
+#     ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+         if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
+            info_ptr->bit_depth = 8;
+#     endif
+
+#     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+         if ((png_ptr->transformations & PNG_16_TO_8) != 0)
+            info_ptr->bit_depth = 8;
+#     endif
+
+#  else
+      /* No 16-bit support: force chopping 16-bit input down to 8, in this case
+       * the app program can chose if both APIs are available by setting the
+       * correct scaling to use.
+       */
+#     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+         /* For compatibility with previous versions use the strip method by
+          * default.  This code works because if PNG_SCALE_16_TO_8 is already
+          * set the code below will do that in preference to the chop.
+          */
+         png_ptr->transformations |= PNG_16_TO_8;
+         info_ptr->bit_depth = 8;
+#     else
+
+#        ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+            png_ptr->transformations |= PNG_SCALE_16_TO_8;
+            info_ptr->bit_depth = 8;
+#        else
+
+            CONFIGURATION ERROR: you must enable at least one 16 to 8 method
+#        endif
+#    endif
+#endif /* !READ_16BIT */
+   }
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+      info_ptr->color_type = (png_byte)(info_ptr->color_type |
+         PNG_COLOR_MASK_COLOR);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+      info_ptr->color_type = (png_byte)(info_ptr->color_type &
+         ~PNG_COLOR_MASK_COLOR);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
+   {
+      if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+          (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+          png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8)
+      {
+         info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
+      }
+   }
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+       info_ptr->bit_depth == 8 &&
+       info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      info_ptr->bit_depth = 16;
+   }
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) != 0 &&
+       (info_ptr->bit_depth < 8))
+      info_ptr->bit_depth = 8;
+#endif
+
+   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      info_ptr->channels = 1;
+
+   else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      info_ptr->channels = 3;
+
+   else
+      info_ptr->channels = 1;
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0)
+   {
+      info_ptr->color_type = (png_byte)(info_ptr->color_type &
+         ~PNG_COLOR_MASK_ALPHA);
+      info_ptr->num_trans = 0;
+   }
+#endif
+
+   if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      info_ptr->channels++;
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+   /* STRIP_ALPHA and FILLER allowed:  MASK_ALPHA bit stripped above */
+   if ((png_ptr->transformations & PNG_FILLER) != 0 &&
+       (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+       info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
+   {
+      info_ptr->channels++;
+      /* If adding a true alpha channel not just filler */
+      if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0)
+         info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+   }
+#endif
+
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+   {
+      if (png_ptr->user_transform_depth != 0)
+         info_ptr->bit_depth = png_ptr->user_transform_depth;
+
+      if (png_ptr->user_transform_channels != 0)
+         info_ptr->channels = png_ptr->user_transform_channels;
+   }
+#endif
+
+   info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
+       info_ptr->bit_depth);
+
+   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
+
+   /* Adding in 1.5.4: cache the above value in png_struct so that we can later
+    * check in png_rowbytes that the user buffer won't get overwritten.  Note
+    * that the field is not always set - if png_read_update_info isn't called
+    * the application has to either not do any transforms or get the calculation
+    * right itself.
+    */
+   png_ptr->info_rowbytes = info_ptr->rowbytes;
+
+#ifndef PNG_READ_EXPAND_SUPPORTED
+   if (png_ptr != NULL)
+      return;
+#endif
+}
+
+#ifdef PNG_READ_PACK_SUPPORTED
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
+ * without changing the actual values.  Thus, if you had a row with
+ * a bit depth of 1, you would end up with bytes that only contained
+ * the numbers 0 or 1.  If you would rather they contain 0 and 255, use
+ * png_do_shift() after this.
+ */
+static void
+png_do_unpack(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_unpack");
+
+   if (row_info->bit_depth < 8)
+   {
+      png_uint_32 i;
+      png_uint_32 row_width=row_info->width;
+
+      switch (row_info->bit_depth)
+      {
+         case 1:
+         {
+            png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
+            png_bytep dp = row + (png_size_t)row_width - 1;
+            png_uint_32 shift = 7U - ((row_width + 7U) & 0x07);
+            for (i = 0; i < row_width; i++)
+            {
+               *dp = (png_byte)((*sp >> shift) & 0x01);
+
+               if (shift == 7)
+               {
+                  shift = 0;
+                  sp--;
+               }
+
+               else
+                  shift++;
+
+               dp--;
+            }
+            break;
+         }
+
+         case 2:
+         {
+
+            png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
+            png_bytep dp = row + (png_size_t)row_width - 1;
+            png_uint_32 shift = ((3U - ((row_width + 3U) & 0x03)) << 1);
+            for (i = 0; i < row_width; i++)
+            {
+               *dp = (png_byte)((*sp >> shift) & 0x03);
+
+               if (shift == 6)
+               {
+                  shift = 0;
+                  sp--;
+               }
+
+               else
+                  shift += 2;
+
+               dp--;
+            }
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
+            png_bytep dp = row + (png_size_t)row_width - 1;
+            png_uint_32 shift = ((1U - ((row_width + 1U) & 0x01)) << 2);
+            for (i = 0; i < row_width; i++)
+            {
+               *dp = (png_byte)((*sp >> shift) & 0x0f);
+
+               if (shift == 4)
+               {
+                  shift = 0;
+                  sp--;
+               }
+
+               else
+                  shift = 4;
+
+               dp--;
+            }
+            break;
+         }
+
+         default:
+            break;
+      }
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_width * row_info->channels;
+   }
+}
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+/* Reverse the effects of png_do_shift.  This routine merely shifts the
+ * pixels back to their significant bits values.  Thus, if you have
+ * a row of bit depth 8, but only 5 are significant, this will shift
+ * the values back to 0 through 31.
+ */
+static void
+png_do_unshift(png_row_infop row_info, png_bytep row,
+    png_const_color_8p sig_bits)
+{
+   int color_type;
+
+   png_debug(1, "in png_do_unshift");
+
+   /* The palette case has already been handled in the _init routine. */
+   color_type = row_info->color_type;
+
+   if (color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      int shift[4];
+      int channels = 0;
+      int bit_depth = row_info->bit_depth;
+
+      if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+      {
+         shift[channels++] = bit_depth - sig_bits->red;
+         shift[channels++] = bit_depth - sig_bits->green;
+         shift[channels++] = bit_depth - sig_bits->blue;
+      }
+
+      else
+      {
+         shift[channels++] = bit_depth - sig_bits->gray;
+      }
+
+      if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      {
+         shift[channels++] = bit_depth - sig_bits->alpha;
+      }
+
+      {
+         int c, have_shift;
+
+         for (c = have_shift = 0; c < channels; ++c)
+         {
+            /* A shift of more than the bit depth is an error condition but it
+             * gets ignored here.
+             */
+            if (shift[c] <= 0 || shift[c] >= bit_depth)
+               shift[c] = 0;
+
+            else
+               have_shift = 1;
+         }
+
+         if (have_shift == 0)
+            return;
+      }
+
+      switch (bit_depth)
+      {
+         default:
+         /* Must be 1bpp gray: should not be here! */
+            /* NOTREACHED */
+            break;
+
+         case 2:
+         /* Must be 2bpp gray */
+         /* assert(channels == 1 && shift[0] == 1) */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+
+            while (bp < bp_end)
+            {
+               int b = (*bp >> 1) & 0x55;
+               *bp++ = (png_byte)b;
+            }
+            break;
+         }
+
+         case 4:
+         /* Must be 4bpp gray */
+         /* assert(channels == 1) */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            int gray_shift = shift[0];
+            int mask =  0xf >> gray_shift;
+
+            mask |= mask << 4;
+
+            while (bp < bp_end)
+            {
+               int b = (*bp >> gray_shift) & mask;
+               *bp++ = (png_byte)b;
+            }
+            break;
+         }
+
+         case 8:
+         /* Single byte components, G, GA, RGB, RGBA */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            int channel = 0;
+
+            while (bp < bp_end)
+            {
+               int b = *bp >> shift[channel];
+               if (++channel >= channels)
+                  channel = 0;
+               *bp++ = (png_byte)b;
+            }
+            break;
+         }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+         case 16:
+         /* Double byte components, G, GA, RGB, RGBA */
+         {
+            png_bytep bp = row;
+            png_bytep bp_end = bp + row_info->rowbytes;
+            int channel = 0;
+
+            while (bp < bp_end)
+            {
+               int value = (bp[0] << 8) + bp[1];
+
+               value >>= shift[channel];
+               if (++channel >= channels)
+                  channel = 0;
+               *bp++ = (png_byte)(value >> 8);
+               *bp++ = (png_byte)value;
+            }
+            break;
+         }
+#endif
+      }
+   }
+}
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale rows of bit depth 16 down to 8 accurately */
+static void
+png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_scale_16_to_8");
+
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep sp = row; /* source */
+      png_bytep dp = row; /* destination */
+      png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+      while (sp < ep)
+      {
+         /* The input is an array of 16-bit components, these must be scaled to
+          * 8 bits each.  For a 16-bit value V the required value (from the PNG
+          * specification) is:
+          *
+          *    (V * 255) / 65535
+          *
+          * This reduces to round(V / 257), or floor((V + 128.5)/257)
+          *
+          * Represent V as the two byte value vhi.vlo.  Make a guess that the
+          * result is the top byte of V, vhi, then the correction to this value
+          * is:
+          *
+          *    error = floor(((V-vhi.vhi) + 128.5) / 257)
+          *          = floor(((vlo-vhi) + 128.5) / 257)
+          *
+          * This can be approximated using integer arithmetic (and a signed
+          * shift):
+          *
+          *    error = (vlo-vhi+128) >> 8;
+          *
+          * The approximate differs from the exact answer only when (vlo-vhi) is
+          * 128; it then gives a correction of +1 when the exact correction is
+          * 0.  This gives 128 errors.  The exact answer (correct for all 16-bit
+          * input values) is:
+          *
+          *    error = (vlo-vhi+128)*65535 >> 24;
+          *
+          * An alternative arithmetic calculation which also gives no errors is:
+          *
+          *    (V * 255 + 32895) >> 16
+          */
+
+         png_int_32 tmp = *sp++; /* must be signed! */
+         tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
+         *dp++ = (png_byte)tmp;
+      }
+
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_info->width * row_info->channels;
+   }
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+static void
+/* Simply discard the low byte.  This was the default behavior prior
+ * to libpng-1.5.4.
+ */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_chop");
+
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep sp = row; /* source */
+      png_bytep dp = row; /* destination */
+      png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+      while (sp < ep)
+      {
+         *dp++ = *sp;
+         sp += 2; /* skip low byte */
+      }
+
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_info->width * row_info->channels;
+   }
+}
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+static void
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_read_swap_alpha");
+
+   {
+      png_uint_32 row_width = row_info->width;
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         /* This converts from RGBA to ARGB */
+         if (row_info->bit_depth == 8)
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save;
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               save = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save;
+            }
+         }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+         /* This converts from RRGGBBAA to AARRGGBB */
+         else
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save[2];
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               save[0] = *(--sp);
+               save[1] = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save[0];
+               *(--dp) = save[1];
+            }
+         }
+#endif
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         /* This converts from GA to AG */
+         if (row_info->bit_depth == 8)
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save;
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               save = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save;
+            }
+         }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+         /* This converts from GGAA to AAGG */
+         else
+         {
+            png_bytep sp = row + row_info->rowbytes;
+            png_bytep dp = sp;
+            png_byte save[2];
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               save[0] = *(--sp);
+               save[1] = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = save[0];
+               *(--dp) = save[1];
+            }
+         }
+#endif
+      }
+   }
+}
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+static void
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_uint_32 row_width;
+   png_debug(1, "in png_do_read_invert_alpha");
+
+   row_width = row_info->width;
+   if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         /* This inverts the alpha channel in RGBA */
+         png_bytep sp = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+
+/*          This does nothing:
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            We can replace it with:
+*/
+            sp-=3;
+            dp=sp;
+         }
+      }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+      /* This inverts the alpha channel in RRGGBBAA */
+      else
+      {
+         png_bytep sp = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+            *(--dp) = (png_byte)(255 - *(--sp));
+
+/*          This does nothing:
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+            We can replace it with:
+*/
+            sp-=6;
+            dp=sp;
+         }
+      }
+#endif
+   }
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         /* This inverts the alpha channel in GA */
+         png_bytep sp = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+            *(--dp) = *(--sp);
+         }
+      }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+      else
+      {
+         /* This inverts the alpha channel in GGAA */
+         png_bytep sp  = row + row_info->rowbytes;
+         png_bytep dp = sp;
+         png_uint_32 i;
+
+         for (i = 0; i < row_width; i++)
+         {
+            *(--dp) = (png_byte)(255 - *(--sp));
+            *(--dp) = (png_byte)(255 - *(--sp));
+/*
+            *(--dp) = *(--sp);
+            *(--dp) = *(--sp);
+*/
+            sp-=2;
+            dp=sp;
+         }
+      }
+#endif
+   }
+}
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+/* Add filler channel if we have RGB color */
+static void
+png_do_read_filler(png_row_infop row_info, png_bytep row,
+    png_uint_32 filler, png_uint_32 flags)
+{
+   png_uint_32 i;
+   png_uint_32 row_width = row_info->width;
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+   png_byte hi_filler = (png_byte)(filler>>8);
+#endif
+   png_byte lo_filler = (png_byte)filler;
+
+   png_debug(1, "in png_do_read_filler");
+
+   if (
+       row_info->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+         {
+            /* This changes the data from G to GX */
+            png_bytep sp = row + (png_size_t)row_width;
+            png_bytep dp =  sp + (png_size_t)row_width;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = lo_filler;
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = lo_filler;
+            row_info->channels = 2;
+            row_info->pixel_depth = 16;
+            row_info->rowbytes = row_width * 2;
+         }
+
+         else
+         {
+            /* This changes the data from G to XG */
+            png_bytep sp = row + (png_size_t)row_width;
+            png_bytep dp = sp  + (png_size_t)row_width;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = lo_filler;
+            }
+            row_info->channels = 2;
+            row_info->pixel_depth = 16;
+            row_info->rowbytes = row_width * 2;
+         }
+      }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+         {
+            /* This changes the data from GG to GGXX */
+            png_bytep sp = row + (png_size_t)row_width * 2;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = lo_filler;
+               *(--dp) = hi_filler;
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = lo_filler;
+            *(--dp) = hi_filler;
+            row_info->channels = 2;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+
+         else
+         {
+            /* This changes the data from GG to XXGG */
+            png_bytep sp = row + (png_size_t)row_width * 2;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = lo_filler;
+               *(--dp) = hi_filler;
+            }
+            row_info->channels = 2;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+      }
+#endif
+   } /* COLOR_TYPE == GRAY */
+   else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+         {
+            /* This changes the data from RGB to RGBX */
+            png_bytep sp = row + (png_size_t)row_width * 3;
+            png_bytep dp = sp  + (png_size_t)row_width;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = lo_filler;
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = lo_filler;
+            row_info->channels = 4;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+
+         else
+         {
+            /* This changes the data from RGB to XRGB */
+            png_bytep sp = row + (png_size_t)row_width * 3;
+            png_bytep dp = sp + (png_size_t)row_width;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = lo_filler;
+            }
+            row_info->channels = 4;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
+         }
+      }
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
+         {
+            /* This changes the data from RRGGBB to RRGGBBXX */
+            png_bytep sp = row + (png_size_t)row_width * 6;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 1; i < row_width; i++)
+            {
+               *(--dp) = lo_filler;
+               *(--dp) = hi_filler;
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+            }
+            *(--dp) = lo_filler;
+            *(--dp) = hi_filler;
+            row_info->channels = 4;
+            row_info->pixel_depth = 64;
+            row_info->rowbytes = row_width * 8;
+         }
+
+         else
+         {
+            /* This changes the data from RRGGBB to XXRRGGBB */
+            png_bytep sp = row + (png_size_t)row_width * 6;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = *(--sp);
+               *(--dp) = lo_filler;
+               *(--dp) = hi_filler;
+            }
+
+            row_info->channels = 4;
+            row_info->pixel_depth = 64;
+            row_info->rowbytes = row_width * 8;
+         }
+      }
+#endif
+   } /* COLOR_TYPE == RGB */
+}
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand grayscale files to RGB, with or without alpha */
+static void
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
+{
+   png_uint_32 i;
+   png_uint_32 row_width = row_info->width;
+
+   png_debug(1, "in png_do_gray_to_rgb");
+
+   if (row_info->bit_depth >= 8 &&
+       (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0)
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This changes G to RGB */
+            png_bytep sp = row + (png_size_t)row_width - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *sp;
+               *(dp--) = *sp;
+               *(dp--) = *(sp--);
+            }
+         }
+
+         else
+         {
+            /* This changes GG to RRGGBB */
+            png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 4;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
+            }
+         }
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This changes GA to RGBA */
+            png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 2;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *(sp--);
+               *(dp--) = *sp;
+               *(dp--) = *sp;
+               *(dp--) = *(sp--);
+            }
+         }
+
+         else
+         {
+            /* This changes GGAA to RRGGBBAA */
+            png_bytep sp = row + (png_size_t)row_width * 4 - 1;
+            png_bytep dp = sp  + (png_size_t)row_width * 4;
+            for (i = 0; i < row_width; i++)
+            {
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *sp;
+               *(dp--) = *(sp - 1);
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
+            }
+         }
+      }
+      row_info->channels = (png_byte)(row_info->channels + 2);
+      row_info->color_type |= PNG_COLOR_MASK_COLOR;
+      row_info->pixel_depth = (png_byte)(row_info->channels *
+          row_info->bit_depth);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+   }
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB files to grayscale, with or without alpha
+ * using the equation given in Poynton's ColorFAQ of 1998-01-04 at
+ * <http://www.inforamp.net/~poynton/>  (THIS LINK IS DEAD June 2008 but
+ * versions dated 1998 through November 2002 have been archived at
+ * https://web.archive.org/web/20000816232553/www.inforamp.net/
+ * ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
+ * Charles Poynton poynton at poynton.com
+ *
+ *     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ *  which can be expressed with integers as
+ *
+ *     Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ *
+ * Poynton's current link (as of January 2003 through July 2011):
+ * <http://www.poynton.com/notes/colour_and_gamma/>
+ * has changed the numbers slightly:
+ *
+ *     Y = 0.2126*R + 0.7152*G + 0.0722*B
+ *
+ *  which can be expressed with integers as
+ *
+ *     Y = (6966 * R + 23436 * G + 2366 * B)/32768
+ *
+ *  Historically, however, libpng uses numbers derived from the ITU-R Rec 709
+ *  end point chromaticities and the D65 white point.  Depending on the
+ *  precision used for the D65 white point this produces a variety of different
+ *  numbers, however if the four decimal place value used in ITU-R Rec 709 is
+ *  used (0.3127,0.3290) the Y calculation would be:
+ *
+ *     Y = (6968 * R + 23435 * G + 2366 * B)/32768
+ *
+ *  While this is correct the rounding results in an overflow for white, because
+ *  the sum of the rounded coefficients is 32769, not 32768.  Consequently
+ *  libpng uses, instead, the closest non-overflowing approximation:
+ *
+ *     Y = (6968 * R + 23434 * G + 2366 * B)/32768
+ *
+ *  Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
+ *  (including an sRGB chunk) then the chromaticities are used to calculate the
+ *  coefficients.  See the chunk handling in pngrutil.c for more information.
+ *
+ *  In all cases the calculation is to be done in a linear colorspace.  If no
+ *  gamma information is available to correct the encoding of the original RGB
+ *  values this results in an implicit assumption that the original PNG RGB
+ *  values were linear.
+ *
+ *  Other integer coefficents can be used via png_set_rgb_to_gray().  Because
+ *  the API takes just red and green coefficients the blue coefficient is
+ *  calculated to make the sum 32768.  This will result in different rounding
+ *  to that used above.
+ */
+static int
+png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
+
+{
+   int rgb_error = 0;
+
+   png_debug(1, "in png_do_rgb_to_gray");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 &&
+       (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+      PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+      PNG_CONST png_uint_32 bc = 32768 - rc - gc;
+      PNG_CONST png_uint_32 row_width = row_info->width;
+      PNG_CONST int have_alpha =
+         (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+
+      if (row_info->bit_depth == 8)
+      {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+         /* Notice that gamma to/from 1 are not necessarily inverses (if
+          * there is an overall gamma correction).  Prior to 1.5.5 this code
+          * checked the linearized values for equality; this doesn't match
+          * the documentation, the original values must be checked.
+          */
+         if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte red   = *(sp++);
+               png_byte green = *(sp++);
+               png_byte blue  = *(sp++);
+
+               if (red != green || red != blue)
+               {
+                  red = png_ptr->gamma_to_1[red];
+                  green = png_ptr->gamma_to_1[green];
+                  blue = png_ptr->gamma_to_1[blue];
+
+                  rgb_error |= 1;
+                  *(dp++) = png_ptr->gamma_from_1[
+                      (rc*red + gc*green + bc*blue + 16384)>>15];
+               }
+
+               else
+               {
+                  /* If there is no overall correction the table will not be
+                   * set.
+                   */
+                  if (png_ptr->gamma_table != NULL)
+                     red = png_ptr->gamma_table[red];
+
+                  *(dp++) = red;
+               }
+
+               if (have_alpha != 0)
+                  *(dp++) = *(sp++);
+            }
+         }
+         else
+#endif
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte red   = *(sp++);
+               png_byte green = *(sp++);
+               png_byte blue  = *(sp++);
+
+               if (red != green || red != blue)
+               {
+                  rgb_error |= 1;
+                  /* NOTE: this is the historical approach which simply
+                   * truncates the results.
+                   */
+                  *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+               }
+
+               else
+                  *(dp++) = red;
+
+               if (have_alpha != 0)
+                  *(dp++) = *(sp++);
+            }
+         }
+      }
+
+      else /* RGB bit_depth == 16 */
+      {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+         if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_uint_16 red, green, blue, w;
+               png_byte hi,lo;
+
+               hi=*(sp)++; lo=*(sp)++; red   = (png_uint_16)((hi << 8) | (lo));
+               hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+               hi=*(sp)++; lo=*(sp)++; blue  = (png_uint_16)((hi << 8) | (lo));
+
+               if (red == green && red == blue)
+               {
+                  if (png_ptr->gamma_16_table != NULL)
+                     w = png_ptr->gamma_16_table[(red & 0xff)
+                         >> png_ptr->gamma_shift][red >> 8];
+
+                  else
+                     w = red;
+               }
+
+               else
+               {
+                  png_uint_16 red_1   = png_ptr->gamma_16_to_1[(red & 0xff)
+                      >> png_ptr->gamma_shift][red>>8];
+                  png_uint_16 green_1 =
+                      png_ptr->gamma_16_to_1[(green & 0xff) >>
+                      png_ptr->gamma_shift][green>>8];
+                  png_uint_16 blue_1  = png_ptr->gamma_16_to_1[(blue & 0xff)
+                      >> png_ptr->gamma_shift][blue>>8];
+                  png_uint_16 gray16  = (png_uint_16)((rc*red_1 + gc*green_1
+                      + bc*blue_1 + 16384)>>15);
+                  w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >>
+                      png_ptr->gamma_shift][gray16 >> 8];
+                  rgb_error |= 1;
+               }
+
+               *(dp++) = (png_byte)((w>>8) & 0xff);
+               *(dp++) = (png_byte)(w & 0xff);
+
+               if (have_alpha != 0)
+               {
+                  *(dp++) = *(sp++);
+                  *(dp++) = *(sp++);
+               }
+            }
+         }
+         else
+#endif
+         {
+            png_bytep sp = row;
+            png_bytep dp = row;
+            png_uint_32 i;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_uint_16 red, green, blue, gray16;
+               png_byte hi,lo;
+
+               hi=*(sp)++; lo=*(sp)++; red   = (png_uint_16)((hi << 8) | (lo));
+               hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
+               hi=*(sp)++; lo=*(sp)++; blue  = (png_uint_16)((hi << 8) | (lo));
+
+               if (red != green || red != blue)
+                  rgb_error |= 1;
+
+               /* From 1.5.5 in the 16-bit case do the accurate conversion even
+                * in the 'fast' case - this is because this is where the code
+                * ends up when handling linear 16-bit data.
+                */
+               gray16  = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
+                  15);
+               *(dp++) = (png_byte)((gray16 >> 8) & 0xff);
+               *(dp++) = (png_byte)(gray16 & 0xff);
+
+               if (have_alpha != 0)
+               {
+                  *(dp++) = *(sp++);
+                  *(dp++) = *(sp++);
+               }
+            }
+         }
+      }
+
+      row_info->channels = (png_byte)(row_info->channels - 2);
+      row_info->color_type = (png_byte)(row_info->color_type &
+          ~PNG_COLOR_MASK_COLOR);
+      row_info->pixel_depth = (png_byte)(row_info->channels *
+          row_info->bit_depth);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+   }
+   return rgb_error;
+}
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* Replace any alpha or transparency with the supplied background color.
+ * "background" is already in the screen gamma, while "background_1" is
+ * at a gamma of 1.0.  Paletted files have already been taken care of.
+ */
+static void
+png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_const_bytep gamma_table = png_ptr->gamma_table;
+   png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
+   png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
+   png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
+   png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
+   png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
+   int gamma_shift = png_ptr->gamma_shift;
+   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
+#endif
+
+   png_bytep sp;
+   png_uint_32 i;
+   png_uint_32 row_width = row_info->width;
+   int shift;
+
+   png_debug(1, "in png_do_compose");
+
+   {
+      switch (row_info->color_type)
+      {
+         case PNG_COLOR_TYPE_GRAY:
+         {
+            switch (row_info->bit_depth)
+            {
+               case 1:
+               {
+                  sp = row;
+                  shift = 7;
+                  for (i = 0; i < row_width; i++)
+                  {
+                     if ((png_uint_16)((*sp >> shift) & 0x01)
+                        == png_ptr->trans_color.gray)
+                     {
+                        unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
+                        tmp |=
+                            (unsigned int)(png_ptr->background.gray << shift);
+                        *sp = (png_byte)(tmp & 0xff);
+                     }
+
+                     if (shift == 0)
+                     {
+                        shift = 7;
+                        sp++;
+                     }
+
+                     else
+                        shift--;
+                  }
+                  break;
+               }
+
+               case 2:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_table != NULL)
+                  {
+                     sp = row;
+                     shift = 6;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x03)
+                            == png_ptr->trans_color.gray)
+                        {
+                           unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+                           tmp |=
+                              (unsigned int)png_ptr->background.gray << shift;
+                           *sp = (png_byte)(tmp & 0xff);
+                        }
+
+                        else
+                        {
+                           unsigned int p = (*sp >> shift) & 0x03;
+                           unsigned int g = (gamma_table [p | (p << 2) |
+                               (p << 4) | (p << 6)] >> 6) & 0x03;
+                           unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+                           tmp |= (unsigned int)(g << shift);
+                           *sp = (png_byte)(tmp & 0xff);
+                        }
+
+                        if (shift == 0)
+                        {
+                           shift = 6;
+                           sp++;
+                        }
+
+                        else
+                           shift -= 2;
+                     }
+                  }
+
+                  else
+#endif
+                  {
+                     sp = row;
+                     shift = 6;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x03)
+                            == png_ptr->trans_color.gray)
+                        {
+                           unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+                           tmp |=
+                               (unsigned int)png_ptr->background.gray << shift;
+                           *sp = (png_byte)(tmp & 0xff);
+                        }
+
+                        if (shift == 0)
+                        {
+                           shift = 6;
+                           sp++;
+                        }
+
+                        else
+                           shift -= 2;
+                     }
+                  }
+                  break;
+               }
+
+               case 4:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_table != NULL)
+                  {
+                     sp = row;
+                     shift = 4;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x0f)
+                            == png_ptr->trans_color.gray)
+                        {
+                           unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+                           tmp |=
+                              (unsigned int)(png_ptr->background.gray << shift);
+                           *sp = (png_byte)(tmp & 0xff);
+                        }
+
+                        else
+                        {
+                           unsigned int p = (*sp >> shift) & 0x0f;
+                           unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
+                              0x0f;
+                           unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+                           tmp |= (unsigned int)(g << shift);
+                           *sp = (png_byte)(tmp & 0xff);
+                        }
+
+                        if (shift == 0)
+                        {
+                           shift = 4;
+                           sp++;
+                        }
+
+                        else
+                           shift -= 4;
+                     }
+                  }
+
+                  else
+#endif
+                  {
+                     sp = row;
+                     shift = 4;
+                     for (i = 0; i < row_width; i++)
+                     {
+                        if ((png_uint_16)((*sp >> shift) & 0x0f)
+                            == png_ptr->trans_color.gray)
+                        {
+                           unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
+                           tmp |=
+                              (unsigned int)(png_ptr->background.gray << shift);
+                           *sp = (png_byte)(tmp & 0xff);
+                        }
+
+                        if (shift == 0)
+                        {
+                           shift = 4;
+                           sp++;
+                        }
+
+                        else
+                           shift -= 4;
+                     }
+                  }
+                  break;
+               }
+
+               case 8:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_table != NULL)
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp++)
+                     {
+                        if (*sp == png_ptr->trans_color.gray)
+                           *sp = (png_byte)png_ptr->background.gray;
+
+                        else
+                           *sp = gamma_table[*sp];
+                     }
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp++)
+                     {
+                        if (*sp == png_ptr->trans_color.gray)
+                           *sp = (png_byte)png_ptr->background.gray;
+                     }
+                  }
+                  break;
+               }
+
+               case 16:
+               {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+                  if (gamma_16 != NULL)
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp += 2)
+                     {
+                        png_uint_16 v;
+
+                        v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+                        if (v == png_ptr->trans_color.gray)
+                        {
+                           /* Background is already in screen gamma */
+                           *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray
+                                & 0xff);
+                        }
+
+                        else
+                        {
+                           v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                           *sp = (png_byte)((v >> 8) & 0xff);
+                           *(sp + 1) = (png_byte)(v & 0xff);
+                        }
+                     }
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     for (i = 0; i < row_width; i++, sp += 2)
+                     {
+                        png_uint_16 v;
+
+                        v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+                        if (v == png_ptr->trans_color.gray)
+                        {
+                           *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray
+                                & 0xff);
+                        }
+                     }
+                  }
+                  break;
+               }
+
+               default:
+                  break;
+            }
+            break;
+         }
+
+         case PNG_COLOR_TYPE_RGB:
+         {
+            if (row_info->bit_depth == 8)
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_table != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 3)
+                  {
+                     if (*sp == png_ptr->trans_color.red &&
+                         *(sp + 1) == png_ptr->trans_color.green &&
+                         *(sp + 2) == png_ptr->trans_color.blue)
+                     {
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+
+                     else
+                     {
+                        *sp = gamma_table[*sp];
+                        *(sp + 1) = gamma_table[*(sp + 1)];
+                        *(sp + 2) = gamma_table[*(sp + 2)];
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 3)
+                  {
+                     if (*sp == png_ptr->trans_color.red &&
+                         *(sp + 1) == png_ptr->trans_color.green &&
+                         *(sp + 2) == png_ptr->trans_color.blue)
+                     {
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+                  }
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_16 != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 6)
+                  {
+                     png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+                     png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+
+                     png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                         + *(sp + 5));
+
+                     if (r == png_ptr->trans_color.red &&
+                         g == png_ptr->trans_color.green &&
+                         b == png_ptr->trans_color.blue)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+
+                     else
+                     {
+                        png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+
+                        v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
+
+                        v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
+                     }
+                  }
+               }
+
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 6)
+                  {
+                     png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+
+                     png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+
+                     png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                         + *(sp + 5));
+
+                     if (r == png_ptr->trans_color.red &&
+                         g == png_ptr->trans_color.green &&
+                         b == png_ptr->trans_color.blue)
+                     {
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+                  }
+               }
+            }
+            break;
+         }
+
+         case PNG_COLOR_TYPE_GRAY_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+                   gamma_table != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 2)
+                  {
+                     png_uint_16 a = *(sp + 1);
+
+                     if (a == 0xff)
+                        *sp = gamma_table[*sp];
+
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)png_ptr->background.gray;
+                     }
+
+                     else
+                     {
+                        png_byte v, w;
+
+                        v = gamma_to_1[*sp];
+                        png_composite(w, v, a, png_ptr->background_1.gray);
+                        if (optimize == 0)
+                           w = gamma_from_1[w];
+                        *sp = w;
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 2)
+                  {
+                     png_byte a = *(sp + 1);
+
+                     if (a == 0)
+                        *sp = (png_byte)png_ptr->background.gray;
+
+                     else if (a < 0xff)
+                        png_composite(*sp, *sp, a, png_ptr->background.gray);
+                  }
+               }
+            }
+            else /* if (png_ptr->bit_depth == 16) */
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+                   gamma_16_to_1 != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+
+                     if (a == (png_uint_16)0xffff)
+                     {
+                        png_uint_16 v;
+
+                        v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                     }
+
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                     }
+
+                     else
+                     {
+                        png_uint_16 g, v, w;
+
+                        g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+                        png_composite_16(v, g, a, png_ptr->background_1.gray);
+                        if (optimize != 0)
+                           w = v;
+                        else
+                           w = gamma_16_from_1[(v & 0xff) >>
+                               gamma_shift][v >> 8];
+                        *sp = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(w & 0xff);
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
+                         + *(sp + 3));
+
+                     if (a == 0)
+                     {
+                        *sp = (png_byte)((png_ptr->background.gray >> 8)
+                                & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
+                     }
+
+                     else if (a < 0xffff)
+                     {
+                        png_uint_16 g, v;
+
+                        g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        png_composite_16(v, g, a, png_ptr->background.gray);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+                     }
+                  }
+               }
+            }
+            break;
+         }
+
+         case PNG_COLOR_TYPE_RGB_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+                   gamma_table != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_byte a = *(sp + 3);
+
+                     if (a == 0xff)
+                     {
+                        *sp = gamma_table[*sp];
+                        *(sp + 1) = gamma_table[*(sp + 1)];
+                        *(sp + 2) = gamma_table[*(sp + 2)];
+                     }
+
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+
+                     else
+                     {
+                        png_byte v, w;
+
+                        v = gamma_to_1[*sp];
+                        png_composite(w, v, a, png_ptr->background_1.red);
+                        if (optimize == 0) w = gamma_from_1[w];
+                        *sp = w;
+
+                        v = gamma_to_1[*(sp + 1)];
+                        png_composite(w, v, a, png_ptr->background_1.green);
+                        if (optimize == 0) w = gamma_from_1[w];
+                        *(sp + 1) = w;
+
+                        v = gamma_to_1[*(sp + 2)];
+                        png_composite(w, v, a, png_ptr->background_1.blue);
+                        if (optimize == 0) w = gamma_from_1[w];
+                        *(sp + 2) = w;
+                     }
+                  }
+               }
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 4)
+                  {
+                     png_byte a = *(sp + 3);
+
+                     if (a == 0)
+                     {
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
+                     }
+
+                     else if (a < 0xff)
+                     {
+                        png_composite(*sp, *sp, a, png_ptr->background.red);
+
+                        png_composite(*(sp + 1), *(sp + 1), a,
+                            png_ptr->background.green);
+
+                        png_composite(*(sp + 2), *(sp + 2), a,
+                            png_ptr->background.blue);
+                     }
+                  }
+               }
+            }
+            else /* if (row_info->bit_depth == 16) */
+            {
+#ifdef PNG_READ_GAMMA_SUPPORTED
+               if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+                   gamma_16_to_1 != NULL)
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 8)
+                  {
+                     png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+                         << 8) + (png_uint_16)(*(sp + 7)));
+
+                     if (a == (png_uint_16)0xffff)
+                     {
+                        png_uint_16 v;
+
+                        v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+
+                        v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
+
+                        v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
+                     }
+
+                     else if (a == 0)
+                     {
+                        /* Background is already in screen gamma */
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+
+                     else
+                     {
+                        png_uint_16 v, w;
+
+                        v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+                        png_composite_16(w, v, a, png_ptr->background_1.red);
+                        if (optimize == 0)
+                           w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+                                8];
+                        *sp = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(w & 0xff);
+
+                        v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
+                        png_composite_16(w, v, a, png_ptr->background_1.green);
+                        if (optimize == 0)
+                           w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+                                8];
+
+                        *(sp + 2) = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(w & 0xff);
+
+                        v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
+                        png_composite_16(w, v, a, png_ptr->background_1.blue);
+                        if (optimize == 0)
+                           w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
+                                8];
+
+                        *(sp + 4) = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(w & 0xff);
+                     }
+                  }
+               }
+
+               else
+#endif
+               {
+                  sp = row;
+                  for (i = 0; i < row_width; i++, sp += 8)
+                  {
+                     png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+                         << 8) + (png_uint_16)(*(sp + 7)));
+
+                     if (a == 0)
+                     {
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
+                                & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green
+                                & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
+                                & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
+                     }
+
+                     else if (a < 0xffff)
+                     {
+                        png_uint_16 v;
+
+                        png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                            + *(sp + 3));
+                        png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                            + *(sp + 5));
+
+                        png_composite_16(v, r, a, png_ptr->background.red);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
+
+                        png_composite_16(v, g, a, png_ptr->background.green);
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
+
+                        png_composite_16(v, b, a, png_ptr->background.blue);
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
+                     }
+                  }
+               }
+            }
+            break;
+         }
+
+         default:
+            break;
+      }
+   }
+}
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* Gamma correct the image, avoiding the alpha channel.  Make sure
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
+ * is 16, use gamma_16_table and gamma_shift.  Build these with
+ * build_gamma_table().
+ */
+static void
+png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+   png_const_bytep gamma_table = png_ptr->gamma_table;
+   png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
+   int gamma_shift = png_ptr->gamma_shift;
+
+   png_bytep sp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+
+   png_debug(1, "in png_do_gamma");
+
+   if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
+       (row_info->bit_depth == 16 && gamma_16_table != NULL)))
+   {
+      switch (row_info->color_type)
+      {
+         case PNG_COLOR_TYPE_RGB:
+         {
+            if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  *sp = gamma_table[*sp];
+                  sp++;
+                  *sp = gamma_table[*sp];
+                  sp++;
+               }
+            }
+
+            else /* if (row_info->bit_depth == 16) */
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v;
+
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+               }
+            }
+            break;
+         }
+
+         case PNG_COLOR_TYPE_RGB_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp++;
+
+                  *sp = gamma_table[*sp];
+                  sp++;
+
+                  *sp = gamma_table[*sp];
+                  sp++;
+
+                  sp++;
+               }
+            }
+
+            else /* if (row_info->bit_depth == 16) */
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+
+                  v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 4;
+               }
+            }
+            break;
+         }
+
+         case PNG_COLOR_TYPE_GRAY_ALPHA:
+         {
+            if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp += 2;
+               }
+            }
+
+            else /* if (row_info->bit_depth == 16) */
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 4;
+               }
+            }
+            break;
+         }
+
+         case PNG_COLOR_TYPE_GRAY:
+         {
+            if (row_info->bit_depth == 2)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i += 4)
+               {
+                  int a = *sp & 0xc0;
+                  int b = *sp & 0x30;
+                  int c = *sp & 0x0c;
+                  int d = *sp & 0x03;
+
+                  *sp = (png_byte)(
+                      ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)])   ) & 0xc0)|
+                      ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+                      ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+                      ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+                  sp++;
+               }
+            }
+
+            if (row_info->bit_depth == 4)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i += 2)
+               {
+                  int msb = *sp & 0xf0;
+                  int lsb = *sp & 0x0f;
+
+                  *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+                      | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+                  sp++;
+               }
+            }
+
+            else if (row_info->bit_depth == 8)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  *sp = gamma_table[*sp];
+                  sp++;
+               }
+            }
+
+            else if (row_info->bit_depth == 16)
+            {
+               sp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+                  *sp = (png_byte)((v >> 8) & 0xff);
+                  *(sp + 1) = (png_byte)(v & 0xff);
+                  sp += 2;
+               }
+            }
+            break;
+         }
+
+         default:
+            break;
+      }
+   }
+}
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* Encode the alpha channel to the output gamma (the input channel is always
+ * linear.)  Called only with color types that have an alpha channel.  Needs the
+ * from_1 tables.
+ */
+static void
+png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
+{
+   png_uint_32 row_width = row_info->width;
+
+   png_debug(1, "in png_do_encode_alpha");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         PNG_CONST png_bytep table = png_ptr->gamma_from_1;
+
+         if (table != NULL)
+         {
+            PNG_CONST int step =
+               (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
+
+            /* The alpha channel is the last component: */
+            row += step - 1;
+
+            for (; row_width > 0; --row_width, row += step)
+               *row = table[*row];
+
+            return;
+         }
+      }
+
+      else if (row_info->bit_depth == 16)
+      {
+         PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
+         PNG_CONST int gamma_shift = png_ptr->gamma_shift;
+
+         if (table != NULL)
+         {
+            PNG_CONST int step =
+               (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
+
+            /* The alpha channel is the last component: */
+            row += step - 2;
+
+            for (; row_width > 0; --row_width, row += step)
+            {
+               png_uint_16 v;
+
+               v = table[*(row + 1) >> gamma_shift][*row];
+               *row = (png_byte)((v >> 8) & 0xff);
+               *(row + 1) = (png_byte)(v & 0xff);
+            }
+
+            return;
+         }
+      }
+   }
+
+   /* Only get to here if called with a weird row_info; no harm has been done,
+    * so just issue a warning.
+    */
+   png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+/* Expands a palette row to an RGB or RGBA row depending
+ * upon whether you supply trans and num_trans.
+ */
+static void
+png_do_expand_palette(png_row_infop row_info, png_bytep row,
+    png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
+{
+   int shift, value;
+   png_bytep sp, dp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+
+   png_debug(1, "in png_do_expand_palette");
+
+   if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (row_info->bit_depth < 8)
+      {
+         switch (row_info->bit_depth)
+         {
+            case 1:
+            {
+               sp = row + (png_size_t)((row_width - 1) >> 3);
+               dp = row + (png_size_t)row_width - 1;
+               shift = 7 - (int)((row_width + 7) & 0x07);
+               for (i = 0; i < row_width; i++)
+               {
+                  if ((*sp >> shift) & 0x01)
+                     *dp = 1;
+
+                  else
+                     *dp = 0;
+
+                  if (shift == 7)
+                  {
+                     shift = 0;
+                     sp--;
+                  }
+
+                  else
+                     shift++;
+
+                  dp--;
+               }
+               break;
+            }
+
+            case 2:
+            {
+               sp = row + (png_size_t)((row_width - 1) >> 2);
+               dp = row + (png_size_t)row_width - 1;
+               shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+               for (i = 0; i < row_width; i++)
+               {
+                  value = (*sp >> shift) & 0x03;
+                  *dp = (png_byte)value;
+                  if (shift == 6)
+                  {
+                     shift = 0;
+                     sp--;
+                  }
+
+                  else
+                     shift += 2;
+
+                  dp--;
+               }
+               break;
+            }
+
+            case 4:
+            {
+               sp = row + (png_size_t)((row_width - 1) >> 1);
+               dp = row + (png_size_t)row_width - 1;
+               shift = (int)((row_width & 0x01) << 2);
+               for (i = 0; i < row_width; i++)
+               {
+                  value = (*sp >> shift) & 0x0f;
+                  *dp = (png_byte)value;
+                  if (shift == 4)
+                  {
+                     shift = 0;
+                     sp--;
+                  }
+
+                  else
+                     shift += 4;
+
+                  dp--;
+               }
+               break;
+            }
+
+            default:
+               break;
+         }
+         row_info->bit_depth = 8;
+         row_info->pixel_depth = 8;
+         row_info->rowbytes = row_width;
+      }
+
+      if (row_info->bit_depth == 8)
+      {
+         {
+            if (num_trans > 0)
+            {
+               sp = row + (png_size_t)row_width - 1;
+               dp = row + ((png_size_t)row_width << 2) - 1;
+
+               for (i = 0; i < row_width; i++)
+               {
+                  if ((int)(*sp) >= num_trans)
+                     *dp-- = 0xff;
+
+                  else
+                     *dp-- = trans_alpha[*sp];
+
+                  *dp-- = palette[*sp].blue;
+                  *dp-- = palette[*sp].green;
+                  *dp-- = palette[*sp].red;
+                  sp--;
+               }
+               row_info->bit_depth = 8;
+               row_info->pixel_depth = 32;
+               row_info->rowbytes = row_width * 4;
+               row_info->color_type = 6;
+               row_info->channels = 4;
+            }
+
+            else
+            {
+               sp = row + (png_size_t)row_width - 1;
+               dp = row + (png_size_t)(row_width * 3) - 1;
+
+               for (i = 0; i < row_width; i++)
+               {
+                  *dp-- = palette[*sp].blue;
+                  *dp-- = palette[*sp].green;
+                  *dp-- = palette[*sp].red;
+                  sp--;
+               }
+
+               row_info->bit_depth = 8;
+               row_info->pixel_depth = 24;
+               row_info->rowbytes = row_width * 3;
+               row_info->color_type = 2;
+               row_info->channels = 3;
+            }
+         }
+      }
+   }
+}
+
+/* If the bit depth < 8, it is expanded to 8.  Also, if the already
+ * expanded transparency value is supplied, an alpha channel is built.
+ */
+static void
+png_do_expand(png_row_infop row_info, png_bytep row,
+    png_const_color_16p trans_color)
+{
+   int shift, value;
+   png_bytep sp, dp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+
+   png_debug(1, "in png_do_expand");
+
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         unsigned int gray = trans_color != NULL ? trans_color->gray : 0;
+
+         if (row_info->bit_depth < 8)
+         {
+            switch (row_info->bit_depth)
+            {
+               case 1:
+               {
+                  gray = (gray & 0x01) * 0xff;
+                  sp = row + (png_size_t)((row_width - 1) >> 3);
+                  dp = row + (png_size_t)row_width - 1;
+                  shift = 7 - (int)((row_width + 7) & 0x07);
+                  for (i = 0; i < row_width; i++)
+                  {
+                     if ((*sp >> shift) & 0x01)
+                        *dp = 0xff;
+
+                     else
+                        *dp = 0;
+
+                     if (shift == 7)
+                     {
+                        shift = 0;
+                        sp--;
+                     }
+
+                     else
+                        shift++;
+
+                     dp--;
+                  }
+                  break;
+               }
+
+               case 2:
+               {
+                  gray = (gray & 0x03) * 0x55;
+                  sp = row + (png_size_t)((row_width - 1) >> 2);
+                  dp = row + (png_size_t)row_width - 1;
+                  shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+                  for (i = 0; i < row_width; i++)
+                  {
+                     value = (*sp >> shift) & 0x03;
+                     *dp = (png_byte)(value | (value << 2) | (value << 4) |
+                        (value << 6));
+                     if (shift == 6)
+                     {
+                        shift = 0;
+                        sp--;
+                     }
+
+                     else
+                        shift += 2;
+
+                     dp--;
+                  }
+                  break;
+               }
+
+               case 4:
+               {
+                  gray = (gray & 0x0f) * 0x11;
+                  sp = row + (png_size_t)((row_width - 1) >> 1);
+                  dp = row + (png_size_t)row_width - 1;
+                  shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+                  for (i = 0; i < row_width; i++)
+                  {
+                     value = (*sp >> shift) & 0x0f;
+                     *dp = (png_byte)(value | (value << 4));
+                     if (shift == 4)
+                     {
+                        shift = 0;
+                        sp--;
+                     }
+
+                     else
+                        shift = 4;
+
+                     dp--;
+                  }
+                  break;
+               }
+
+               default:
+                  break;
+            }
+
+            row_info->bit_depth = 8;
+            row_info->pixel_depth = 8;
+            row_info->rowbytes = row_width;
+         }
+
+         if (trans_color != NULL)
+         {
+            if (row_info->bit_depth == 8)
+            {
+               gray = gray & 0xff;
+               sp = row + (png_size_t)row_width - 1;
+               dp = row + ((png_size_t)row_width << 1) - 1;
+
+               for (i = 0; i < row_width; i++)
+               {
+                  if ((*sp & 0xffU) == gray)
+                     *dp-- = 0;
+
+                  else
+                     *dp-- = 0xff;
+
+                  *dp-- = *sp--;
+               }
+            }
+
+            else if (row_info->bit_depth == 16)
+            {
+               unsigned int gray_high = (gray >> 8) & 0xff;
+               unsigned int gray_low = gray & 0xff;
+               sp = row + row_info->rowbytes - 1;
+               dp = row + (row_info->rowbytes << 1) - 1;
+               for (i = 0; i < row_width; i++)
+               {
+                  if ((*(sp - 1) & 0xffU) == gray_high &&
+                      (*(sp) & 0xffU) == gray_low)
+                  {
+                     *dp-- = 0;
+                     *dp-- = 0;
+                  }
+
+                  else
+                  {
+                     *dp-- = 0xff;
+                     *dp-- = 0xff;
+                  }
+
+                  *dp-- = *sp--;
+                  *dp-- = *sp--;
+               }
+            }
+
+            row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+            row_info->channels = 2;
+            row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
+            row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+                row_width);
+         }
+      }
+      else if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
+          trans_color != NULL)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            png_byte red = (png_byte)(trans_color->red & 0xff);
+            png_byte green = (png_byte)(trans_color->green & 0xff);
+            png_byte blue = (png_byte)(trans_color->blue & 0xff);
+            sp = row + (png_size_t)row_info->rowbytes - 1;
+            dp = row + ((png_size_t)row_width << 2) - 1;
+            for (i = 0; i < row_width; i++)
+            {
+               if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
+                  *dp-- = 0;
+
+               else
+                  *dp-- = 0xff;
+
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+            }
+         }
+         else if (row_info->bit_depth == 16)
+         {
+            png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
+            png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
+            png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
+            png_byte red_low = (png_byte)(trans_color->red & 0xff);
+            png_byte green_low = (png_byte)(trans_color->green & 0xff);
+            png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
+            sp = row + row_info->rowbytes - 1;
+            dp = row + ((png_size_t)row_width << 3) - 1;
+            for (i = 0; i < row_width; i++)
+            {
+               if (*(sp - 5) == red_high &&
+                   *(sp - 4) == red_low &&
+                   *(sp - 3) == green_high &&
+                   *(sp - 2) == green_low &&
+                   *(sp - 1) == blue_high &&
+                   *(sp    ) == blue_low)
+               {
+                  *dp-- = 0;
+                  *dp-- = 0;
+               }
+
+               else
+               {
+                  *dp-- = 0xff;
+                  *dp-- = 0xff;
+               }
+
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+               *dp-- = *sp--;
+            }
+         }
+         row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+         row_info->channels = 4;
+         row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+      }
+   }
+}
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+/* If the bit depth is 8 and the color type is not a palette type expand the
+ * whole row to 16 bits.  Has no effect otherwise.
+ */
+static void
+png_do_expand_16(png_row_infop row_info, png_bytep row)
+{
+   if (row_info->bit_depth == 8 &&
+      row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      /* The row have a sequence of bytes containing [0..255] and we need
+       * to turn it into another row containing [0..65535], to do this we
+       * calculate:
+       *
+       *  (input / 255) * 65535
+       *
+       *  Which happens to be exactly input * 257 and this can be achieved
+       *  simply by byte replication in place (copying backwards).
+       */
+      png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
+      png_byte *dp = sp + row_info->rowbytes;  /* destination, end + 1 */
+      while (dp > sp)
+      {
+         dp[-2] = dp[-1] = *--sp; dp -= 2;
+      }
+
+      row_info->rowbytes *= 2;
+      row_info->bit_depth = 16;
+      row_info->pixel_depth = (png_byte)(row_info->channels * 16);
+   }
+}
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+static void
+png_do_quantize(png_row_infop row_info, png_bytep row,
+    png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
+{
+   png_bytep sp, dp;
+   png_uint_32 i;
+   png_uint_32 row_width=row_info->width;
+
+   png_debug(1, "in png_do_quantize");
+
+   if (row_info->bit_depth == 8)
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
+      {
+         int r, g, b, p;
+         sp = row;
+         dp = row;
+         for (i = 0; i < row_width; i++)
+         {
+            r = *sp++;
+            g = *sp++;
+            b = *sp++;
+
+            /* This looks real messy, but the compiler will reduce
+             * it down to a reasonable formula.  For example, with
+             * 5 bits per color, we get:
+             * p = (((r >> 3) & 0x1f) << 10) |
+             *    (((g >> 3) & 0x1f) << 5) |
+             *    ((b >> 3) & 0x1f);
+             */
+            p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+                ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+                (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+                (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+                ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+                (PNG_QUANTIZE_BLUE_BITS)) |
+                ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+                ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+            *dp++ = palette_lookup[p];
+         }
+
+         row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+         row_info->channels = 1;
+         row_info->pixel_depth = row_info->bit_depth;
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+         palette_lookup != NULL)
+      {
+         int r, g, b, p;
+         sp = row;
+         dp = row;
+         for (i = 0; i < row_width; i++)
+         {
+            r = *sp++;
+            g = *sp++;
+            b = *sp++;
+            sp++;
+
+            p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+                ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+                (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+                (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+                ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+                (PNG_QUANTIZE_BLUE_BITS)) |
+                ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+                ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
+
+            *dp++ = palette_lookup[p];
+         }
+
+         row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+         row_info->channels = 1;
+         row_info->pixel_depth = row_info->bit_depth;
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+         quantize_lookup)
+      {
+         sp = row;
+
+         for (i = 0; i < row_width; i++, sp++)
+         {
+            *sp = quantize_lookup[*sp];
+         }
+      }
+   }
+}
+#endif /* READ_QUANTIZE */
+
+/* Transform the row.  The order of transformations is significant,
+ * and is very touchy.  If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
+void /* PRIVATE */
+png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+   png_debug(1, "in png_do_read_transformations");
+
+   if (png_ptr->row_buf == NULL)
+   {
+      /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
+       * error is incredibly rare and incredibly easy to debug without this
+       * information.
+       */
+      png_error(png_ptr, "NULL row buffer");
+   }
+
+   /* The following is debugging; prior to 1.5.4 the code was never compiled in;
+    * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
+    * PNG_WARN_UNINITIALIZED_ROW removed.  In 1.6 the new flag is set only for
+    * all transformations, however in practice the ROW_INIT always gets done on
+    * demand, if necessary.
+    */
+   if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
+       (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
+   {
+      /* Application has failed to call either png_read_start_image() or
+       * png_read_update_info() after setting transforms that expand pixels.
+       * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
+       */
+      png_error(png_ptr, "Uninitialized row");
+   }
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   if ((png_ptr->transformations & PNG_EXPAND) != 0)
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         png_do_expand_palette(row_info, png_ptr->row_buf + 1,
+             png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
+      }
+
+      else
+      {
+         if (png_ptr->num_trans != 0 &&
+             (png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
+            png_do_expand(row_info, png_ptr->row_buf + 1,
+                &(png_ptr->trans_color));
+
+         else
+            png_do_expand(row_info, png_ptr->row_buf + 1,
+                NULL);
+      }
+   }
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) == 0 &&
+       (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+       row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+          0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
+   {
+      int rgb_error =
+          png_do_rgb_to_gray(png_ptr, row_info,
+              png_ptr->row_buf + 1);
+
+      if (rgb_error != 0)
+      {
+         png_ptr->rgb_to_gray_status=1;
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+             PNG_RGB_TO_GRAY_WARN)
+            png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+             PNG_RGB_TO_GRAY_ERR)
+            png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+      }
+   }
+#endif
+
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ *   In most cases, the "simple transparency" should be done prior to doing
+ *   gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ *   pixel is transparent.  You would also need to make sure that the
+ *   transparency information is upgraded to RGB.
+ *
+ *   To summarize, the current flow is:
+ *   - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ *                                   with background "in place" if transparent,
+ *                                   convert to RGB if necessary
+ *   - Gray + alpha -> composite with gray background and remove alpha bytes,
+ *                                   convert to RGB if necessary
+ *
+ *   To support RGB backgrounds for gray images we need:
+ *   - Gray + simple transparency -> convert to RGB + simple transparency,
+ *                                   compare 3 or 6 bytes and composite with
+ *                                   background "in place" if transparent
+ *                                   (3x compare/pixel compared to doing
+ *                                   composite with gray bkgrnd)
+ *   - Gray + alpha -> convert to RGB + alpha, composite with background and
+ *                                   remove alpha bytes (3x float
+ *                                   operations/pixel compared with composite
+ *                                   on gray background)
+ *
+ *  Greg's change will do this.  The reason it wasn't done before is for
+ *  performance, as this increases the per-pixel operations.  If we would check
+ *  in advance if the background was gray or RGB, and position the gray-to-RGB
+ *  transform appropriately, then it would save a lot of work/time.
+ */
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   /* If gray -> RGB, do so now only if background is non-gray; else do later
+    * for performance reasons
+    */
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0)
+      png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0)
+      png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   if ((png_ptr->transformations & PNG_GAMMA) != 0 &&
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+      /* Because RGB_TO_GRAY does the gamma transform. */
+      (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 &&
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+      /* Because PNG_COMPOSE does the gamma transform if there is something to
+       * do (if there is an alpha channel or transparency.)
+       */
+       !((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       ((png_ptr->num_trans != 0) ||
+       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) &&
+#endif
+      /* Because png_init_read_transformations transforms the palette, unless
+       * RGB_TO_GRAY will do the transform.
+       */
+       (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+      png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+       row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+          0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+       (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
+      png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* There is no harm in doing both of these because only one has any effect,
+    * by putting the 'scale' option first if the app asks for scale (either by
+    * calling the API or in a TRANSFORM flag) this is what happens.
+    */
+   if ((png_ptr->transformations & PNG_16_TO_8) != 0)
+      png_do_chop(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
+   {
+      png_do_quantize(row_info, png_ptr->row_buf + 1,
+          png_ptr->palette_lookup, png_ptr->quantize_index);
+
+      if (row_info->rowbytes == 0)
+         png_error(png_ptr, "png_do_quantize returned rowbytes=0");
+   }
+#endif /* READ_QUANTIZE */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   /* Do the expansion now, after all the arithmetic has been done.  Notice
+    * that previous transformations can handle the PNG_EXPAND_16 flag if this
+    * is efficient (particularly true in the case of gamma correction, where
+    * better accuracy results faster!)
+    */
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
+      png_do_expand_16(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   /* NOTE: moved here in 1.5.4 (from much later in this list.) */
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0)
+      png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_SUPPORTED
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+      png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+      png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_SHIFT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
+      png_do_unshift(row_info, png_ptr->row_buf + 1,
+          &(png_ptr->shift));
+#endif
+
+#ifdef PNG_READ_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) != 0)
+      png_do_unpack(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   /* Added at libpng-1.5.10 */
+   if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+       png_ptr->num_palette_max >= 0)
+      png_do_check_palette_indexes(png_ptr, row_info);
+#endif
+
+#ifdef PNG_READ_BGR_SUPPORTED
+   if ((png_ptr->transformations & PNG_BGR) != 0)
+      png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+      png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_do_read_filler(row_info, png_ptr->row_buf + 1,
+          (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+      png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_16BIT_SUPPORTED
+#ifdef PNG_READ_SWAP_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+      png_do_swap(row_info, png_ptr->row_buf + 1);
+#endif
+#endif
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+   {
+      if (png_ptr->read_user_transform_fn != NULL)
+         (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+             (png_ptr,     /* png_ptr */
+             row_info,     /* row_info: */
+                /*  png_uint_32 width;       width of row */
+                /*  png_size_t rowbytes;     number of bytes in row */
+                /*  png_byte color_type;     color type of pixels */
+                /*  png_byte bit_depth;      bit depth of samples */
+                /*  png_byte channels;       number of channels (1-4) */
+                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
+             png_ptr->row_buf + 1);    /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+      if (png_ptr->user_transform_depth != 0)
+         row_info->bit_depth = png_ptr->user_transform_depth;
+
+      if (png_ptr->user_transform_channels != 0)
+         row_info->channels = png_ptr->user_transform_channels;
+#endif
+      row_info->pixel_depth = (png_byte)(row_info->bit_depth *
+          row_info->channels);
+
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
+   }
+#endif
+}
+
+#endif /* READ_TRANSFORMS */
+#endif /* READ */
diff --git a/xs/src/png/libpng/pngrutil.c b/xs/src/png/libpng/pngrutil.c
new file mode 100644
index 000000000..8692933bd
--- /dev/null
+++ b/xs/src/png/libpng/pngrutil.c
@@ -0,0 +1,4661 @@
+
+/* pngrutil.c - utilities to read a PNG file
+ *
+ * Last changed in libpng 1.6.33 [September 28, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file contains routines that are only called from within
+ * libpng itself during the course of reading an image.
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+png_uint_32 PNGAPI
+png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
+{
+   png_uint_32 uval = png_get_uint_32(buf);
+
+   if (uval > PNG_UINT_31_MAX)
+      png_error(png_ptr, "PNG unsigned integer out of range");
+
+   return (uval);
+}
+
+#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
+/* The following is a variation on the above for use with the fixed
+ * point values used for gAMA and cHRM.  Instead of png_error it
+ * issues a warning and returns (-1) - an invalid value because both
+ * gAMA and cHRM use *unsigned* integers for fixed point values.
+ */
+#define PNG_FIXED_ERROR (-1)
+
+static png_fixed_point /* PRIVATE */
+png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
+{
+   png_uint_32 uval = png_get_uint_32(buf);
+
+   if (uval <= PNG_UINT_31_MAX)
+      return (png_fixed_point)uval; /* known to be in range */
+
+   /* The caller can turn off the warning by passing NULL. */
+   if (png_ptr != NULL)
+      png_warning(png_ptr, "PNG fixed point integer out of range");
+
+   return PNG_FIXED_ERROR;
+}
+#endif
+
+#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
+/* NOTE: the read macros will obscure these definitions, so that if
+ * PNG_USE_READ_MACROS is set the library will not use them internally,
+ * but the APIs will still be available externally.
+ *
+ * The parentheses around "PNGAPI function_name" in the following three
+ * functions are necessary because they allow the macros to co-exist with
+ * these (unused but exported) functions.
+ */
+
+/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
+png_uint_32 (PNGAPI
+png_get_uint_32)(png_const_bytep buf)
+{
+   png_uint_32 uval =
+       ((png_uint_32)(*(buf    )) << 24) +
+       ((png_uint_32)(*(buf + 1)) << 16) +
+       ((png_uint_32)(*(buf + 2)) <<  8) +
+       ((png_uint_32)(*(buf + 3))      ) ;
+
+   return uval;
+}
+
+/* Grab a signed 32-bit integer from a buffer in big-endian format.  The
+ * data is stored in the PNG file in two's complement format and there
+ * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
+ * the following code does a two's complement to native conversion.
+ */
+png_int_32 (PNGAPI
+png_get_int_32)(png_const_bytep buf)
+{
+   png_uint_32 uval = png_get_uint_32(buf);
+   if ((uval & 0x80000000) == 0) /* non-negative */
+      return (png_int_32)uval;
+
+   uval = (uval ^ 0xffffffff) + 1;  /* 2's complement: -x = ~x+1 */
+   if ((uval & 0x80000000) == 0) /* no overflow */
+      return -(png_int_32)uval;
+   /* The following has to be safe; this function only gets called on PNG data
+    * and if we get here that data is invalid.  0 is the most safe value and
+    * if not then an attacker would surely just generate a PNG with 0 instead.
+    */
+   return 0;
+}
+
+/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
+png_uint_16 (PNGAPI
+png_get_uint_16)(png_const_bytep buf)
+{
+   /* ANSI-C requires an int value to accomodate at least 16 bits so this
+    * works and allows the compiler not to worry about possible narrowing
+    * on 32-bit systems.  (Pre-ANSI systems did not make integers smaller
+    * than 16 bits either.)
+    */
+   unsigned int val =
+       ((unsigned int)(*buf) << 8) +
+       ((unsigned int)(*(buf + 1)));
+
+   return (png_uint_16)val;
+}
+
+#endif /* READ_INT_FUNCTIONS */
+
+/* Read and check the PNG file signature */
+void /* PRIVATE */
+png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
+{
+   png_size_t num_checked, num_to_check;
+
+   /* Exit if the user application does not expect a signature. */
+   if (png_ptr->sig_bytes >= 8)
+      return;
+
+   num_checked = png_ptr->sig_bytes;
+   num_to_check = 8 - num_checked;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
+#endif
+
+   /* The signature must be serialized in a single I/O call. */
+   png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
+   png_ptr->sig_bytes = 8;
+
+   if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0)
+   {
+      if (num_checked < 4 &&
+          png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
+         png_error(png_ptr, "Not a PNG file");
+      else
+         png_error(png_ptr, "PNG file corrupted by ASCII conversion");
+   }
+   if (num_checked < 3)
+      png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structrp png_ptr)
+{
+   png_byte buf[8];
+   png_uint_32 length;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
+#endif
+
+   /* Read the length and the chunk name.
+    * This must be performed in a single I/O call.
+    */
+   png_read_data(png_ptr, buf, 8);
+   length = png_get_uint_31(png_ptr, buf);
+
+   /* Put the chunk name into png_ptr->chunk_name. */
+   png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
+
+   png_debug2(0, "Reading %lx chunk, length = %lu",
+       (unsigned long)png_ptr->chunk_name, (unsigned long)length);
+
+   /* Reset the crc and run it over the chunk name. */
+   png_reset_crc(png_ptr);
+   png_calculate_crc(png_ptr, buf + 4, 4);
+
+   /* Check to see if chunk name is valid. */
+   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+
+   /* Check for too-large chunk length */
+   png_check_chunk_length(png_ptr, length);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
+#endif
+
+   return length;
+}
+
+/* Read data, and (optionally) run it through the CRC. */
+void /* PRIVATE */
+png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_read_data(png_ptr, buf, length);
+   png_calculate_crc(png_ptr, buf, length);
+}
+
+/* Optionally skip data and then check the CRC.  Depending on whether we
+ * are reading an ancillary or critical chunk, and how the program has set
+ * things up, we may calculate the CRC on the data and print a message.
+ * Returns '1' if there was a CRC error, '0' otherwise.
+ */
+int /* PRIVATE */
+png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
+{
+   /* The size of the local buffer for inflate is a good guess as to a
+    * reasonable size to use for buffering reads from the application.
+    */
+   while (skip > 0)
+   {
+      png_uint_32 len;
+      png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+      len = (sizeof tmpbuf);
+      if (len > skip)
+         len = skip;
+      skip -= len;
+
+      png_crc_read(png_ptr, tmpbuf, len);
+   }
+
+   if (png_crc_error(png_ptr) != 0)
+   {
+      if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ?
+          (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 :
+          (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0)
+      {
+         png_chunk_warning(png_ptr, "CRC error");
+      }
+
+      else
+         png_chunk_error(png_ptr, "CRC error");
+
+      return (1);
+   }
+
+   return (0);
+}
+
+/* Compare the CRC stored in the PNG file with that calculated by libpng from
+ * the data it has read thus far.
+ */
+int /* PRIVATE */
+png_crc_error(png_structrp png_ptr)
+{
+   png_byte crc_bytes[4];
+   png_uint_32 crc;
+   int need_crc = 1;
+
+   if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
+   {
+      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
+          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
+         need_crc = 0;
+   }
+
+   else /* critical */
+   {
+      if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
+         need_crc = 0;
+   }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
+#endif
+
+   /* The chunk CRC must be serialized in a single I/O call. */
+   png_read_data(png_ptr, crc_bytes, 4);
+
+   if (need_crc != 0)
+   {
+      crc = png_get_uint_32(crc_bytes);
+      return ((int)(crc != png_ptr->crc));
+   }
+
+   else
+      return (0);
+}
+
+#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
+    defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
+    defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
+    defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED)
+/* Manage the read buffer; this simply reallocates the buffer if it is not small
+ * enough (or if it is not allocated).  The routine returns a pointer to the
+ * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
+ * it will call png_error (via png_malloc) on failure.  (warn == 2 means
+ * 'silent').
+ */
+static png_bytep
+png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
+{
+   png_bytep buffer = png_ptr->read_buffer;
+
+   if (buffer != NULL && new_size > png_ptr->read_buffer_size)
+   {
+      png_ptr->read_buffer = NULL;
+      png_ptr->read_buffer = NULL;
+      png_ptr->read_buffer_size = 0;
+      png_free(png_ptr, buffer);
+      buffer = NULL;
+   }
+
+   if (buffer == NULL)
+   {
+      buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
+
+      if (buffer != NULL)
+      {
+         memset(buffer, 0, new_size); /* just in case */
+         png_ptr->read_buffer = buffer;
+         png_ptr->read_buffer_size = new_size;
+      }
+
+      else if (warn < 2) /* else silent */
+      {
+         if (warn != 0)
+             png_chunk_warning(png_ptr, "insufficient memory to read chunk");
+
+         else
+             png_chunk_error(png_ptr, "insufficient memory to read chunk");
+      }
+   }
+
+   return buffer;
+}
+#endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */
+
+/* png_inflate_claim: claim the zstream for some nefarious purpose that involves
+ * decompression.  Returns Z_OK on success, else a zlib error code.  It checks
+ * the owner but, in final release builds, just issues a warning if some other
+ * chunk apparently owns the stream.  Prior to release it does a png_error.
+ */
+static int
+png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
+{
+   if (png_ptr->zowner != 0)
+   {
+      char msg[64];
+
+      PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
+      /* So the message that results is "<chunk> using zstream"; this is an
+       * internal error, but is very useful for debugging.  i18n requirements
+       * are minimal.
+       */
+      (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
+#if PNG_RELEASE_BUILD
+      png_chunk_warning(png_ptr, msg);
+      png_ptr->zowner = 0;
+#else
+      png_chunk_error(png_ptr, msg);
+#endif
+   }
+
+   /* Implementation note: unlike 'png_deflate_claim' this internal function
+    * does not take the size of the data as an argument.  Some efficiency could
+    * be gained by using this when it is known *if* the zlib stream itself does
+    * not record the number; however, this is an illusion: the original writer
+    * of the PNG may have selected a lower window size, and we really must
+    * follow that because, for systems with with limited capabilities, we
+    * would otherwise reject the application's attempts to use a smaller window
+    * size (zlib doesn't have an interface to say "this or lower"!).
+    *
+    * inflateReset2 was added to zlib 1.2.4; before this the window could not be
+    * reset, therefore it is necessary to always allocate the maximum window
+    * size with earlier zlibs just in case later compressed chunks need it.
+    */
+   {
+      int ret; /* zlib return code */
+#if ZLIB_VERNUM >= 0x1240
+      int window_bits = 0;
+
+# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW)
+      if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
+          PNG_OPTION_ON)
+      {
+         window_bits = 15;
+         png_ptr->zstream_start = 0; /* fixed window size */
+      }
+
+      else
+      {
+         png_ptr->zstream_start = 1;
+      }
+# endif
+
+#endif /* ZLIB_VERNUM >= 0x1240 */
+
+      /* Set this for safety, just in case the previous owner left pointers to
+       * memory allocations.
+       */
+      png_ptr->zstream.next_in = NULL;
+      png_ptr->zstream.avail_in = 0;
+      png_ptr->zstream.next_out = NULL;
+      png_ptr->zstream.avail_out = 0;
+
+      if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+      {
+#if ZLIB_VERNUM >= 0x1240
+         ret = inflateReset2(&png_ptr->zstream, window_bits);
+#else
+         ret = inflateReset(&png_ptr->zstream);
+#endif
+      }
+
+      else
+      {
+#if ZLIB_VERNUM >= 0x1240
+         ret = inflateInit2(&png_ptr->zstream, window_bits);
+#else
+         ret = inflateInit(&png_ptr->zstream);
+#endif
+
+         if (ret == Z_OK)
+            png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+      }
+
+#if ZLIB_VERNUM >= 0x1290 && \
+   defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_IGNORE_ADLER32)
+      if (((png_ptr->options >> PNG_IGNORE_ADLER32) & 3) == PNG_OPTION_ON)
+         /* Turn off validation of the ADLER32 checksum in IDAT chunks */
+         ret = inflateValidate(&png_ptr->zstream, 0);
+#endif
+
+      if (ret == Z_OK)
+         png_ptr->zowner = owner;
+
+      else
+         png_zstream_error(png_ptr, ret);
+
+      return ret;
+   }
+
+#ifdef window_bits
+# undef window_bits
+#endif
+}
+
+#if ZLIB_VERNUM >= 0x1240
+/* Handle the start of the inflate stream if we called inflateInit2(strm,0);
+ * in this case some zlib versions skip validation of the CINFO field and, in
+ * certain circumstances, libpng may end up displaying an invalid image, in
+ * contrast to implementations that call zlib in the normal way (e.g. libpng
+ * 1.5).
+ */
+int /* PRIVATE */
+png_zlib_inflate(png_structrp png_ptr, int flush)
+{
+   if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0)
+   {
+      if ((*png_ptr->zstream.next_in >> 4) > 7)
+      {
+         png_ptr->zstream.msg = "invalid window size (libpng)";
+         return Z_DATA_ERROR;
+      }
+
+      png_ptr->zstream_start = 0;
+   }
+
+   return inflate(&png_ptr->zstream, flush);
+}
+#endif /* Zlib >= 1.2.4 */
+
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#if defined(PNG_READ_zTXt_SUPPORTED) || defined (PNG_READ_iTXt_SUPPORTED)
+/* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
+ * allow the caller to do multiple calls if required.  If the 'finish' flag is
+ * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
+ * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
+ * Z_OK or Z_STREAM_END will be returned on success.
+ *
+ * The input and output sizes are updated to the actual amounts of data consumed
+ * or written, not the amount available (as in a z_stream).  The data pointers
+ * are not changed, so the next input is (data+input_size) and the next
+ * available output is (output+output_size).
+ */
+static int
+png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
+    /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
+    /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
+{
+   if (png_ptr->zowner == owner) /* Else not claimed */
+   {
+      int ret;
+      png_alloc_size_t avail_out = *output_size_ptr;
+      png_uint_32 avail_in = *input_size_ptr;
+
+      /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
+       * can't even necessarily handle 65536 bytes) because the type uInt is
+       * "16 bits or more".  Consequently it is necessary to chunk the input to
+       * zlib.  This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
+       * maximum value that can be stored in a uInt.)  It is possible to set
+       * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
+       * a performance advantage, because it reduces the amount of data accessed
+       * at each step and that may give the OS more time to page it in.
+       */
+      png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+      /* avail_in and avail_out are set below from 'size' */
+      png_ptr->zstream.avail_in = 0;
+      png_ptr->zstream.avail_out = 0;
+
+      /* Read directly into the output if it is available (this is set to
+       * a local buffer below if output is NULL).
+       */
+      if (output != NULL)
+         png_ptr->zstream.next_out = output;
+
+      do
+      {
+         uInt avail;
+         Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+
+         /* zlib INPUT BUFFER */
+         /* The setting of 'avail_in' used to be outside the loop; by setting it
+          * inside it is possible to chunk the input to zlib and simply rely on
+          * zlib to advance the 'next_in' pointer.  This allows arbitrary
+          * amounts of data to be passed through zlib at the unavoidable cost of
+          * requiring a window save (memcpy of up to 32768 output bytes)
+          * every ZLIB_IO_MAX input bytes.
+          */
+         avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
+
+         avail = ZLIB_IO_MAX;
+
+         if (avail_in < avail)
+            avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
+
+         avail_in -= avail;
+         png_ptr->zstream.avail_in = avail;
+
+         /* zlib OUTPUT BUFFER */
+         avail_out += png_ptr->zstream.avail_out; /* not written last time */
+
+         avail = ZLIB_IO_MAX; /* maximum zlib can process */
+
+         if (output == NULL)
+         {
+            /* Reset the output buffer each time round if output is NULL and
+             * make available the full buffer, up to 'remaining_space'
+             */
+            png_ptr->zstream.next_out = local_buffer;
+            if ((sizeof local_buffer) < avail)
+               avail = (sizeof local_buffer);
+         }
+
+         if (avail_out < avail)
+            avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
+
+         png_ptr->zstream.avail_out = avail;
+         avail_out -= avail;
+
+         /* zlib inflate call */
+         /* In fact 'avail_out' may be 0 at this point, that happens at the end
+          * of the read when the final LZ end code was not passed at the end of
+          * the previous chunk of input data.  Tell zlib if we have reached the
+          * end of the output buffer.
+          */
+         ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH :
+             (finish ? Z_FINISH : Z_SYNC_FLUSH));
+      } while (ret == Z_OK);
+
+      /* For safety kill the local buffer pointer now */
+      if (output == NULL)
+         png_ptr->zstream.next_out = NULL;
+
+      /* Claw back the 'size' and 'remaining_space' byte counts. */
+      avail_in += png_ptr->zstream.avail_in;
+      avail_out += png_ptr->zstream.avail_out;
+
+      /* Update the input and output sizes; the updated values are the amount
+       * consumed or written, effectively the inverse of what zlib uses.
+       */
+      if (avail_out > 0)
+         *output_size_ptr -= avail_out;
+
+      if (avail_in > 0)
+         *input_size_ptr -= avail_in;
+
+      /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
+      png_zstream_error(png_ptr, ret);
+      return ret;
+   }
+
+   else
+   {
+      /* This is a bad internal error.  The recovery assigns to the zstream msg
+       * pointer, which is not owned by the caller, but this is safe; it's only
+       * used on errors!
+       */
+      png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+      return Z_STREAM_ERROR;
+   }
+}
+
+/*
+ * Decompress trailing data in a chunk.  The assumption is that read_buffer
+ * points at an allocated area holding the contents of a chunk with a
+ * trailing compressed part.  What we get back is an allocated area
+ * holding the original prefix part and an uncompressed version of the
+ * trailing part (the malloc area passed in is freed).
+ */
+static int
+png_decompress_chunk(png_structrp png_ptr,
+    png_uint_32 chunklength, png_uint_32 prefix_size,
+    png_alloc_size_t *newlength /* must be initialized to the maximum! */,
+    int terminate /*add a '\0' to the end of the uncompressed data*/)
+{
+   /* TODO: implement different limits for different types of chunk.
+    *
+    * The caller supplies *newlength set to the maximum length of the
+    * uncompressed data, but this routine allocates space for the prefix and
+    * maybe a '\0' terminator too.  We have to assume that 'prefix_size' is
+    * limited only by the maximum chunk size.
+    */
+   png_alloc_size_t limit = PNG_SIZE_MAX;
+
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_malloc_max > 0 &&
+       png_ptr->user_chunk_malloc_max < limit)
+      limit = png_ptr->user_chunk_malloc_max;
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+   if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+      limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+
+   if (limit >= prefix_size + (terminate != 0))
+   {
+      int ret;
+
+      limit -= prefix_size + (terminate != 0);
+
+      if (limit < *newlength)
+         *newlength = limit;
+
+      /* Now try to claim the stream. */
+      ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
+
+      if (ret == Z_OK)
+      {
+         png_uint_32 lzsize = chunklength - prefix_size;
+
+         ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+             /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
+             /* output: */ NULL, newlength);
+
+         if (ret == Z_STREAM_END)
+         {
+            /* Use 'inflateReset' here, not 'inflateReset2' because this
+             * preserves the previously decided window size (otherwise it would
+             * be necessary to store the previous window size.)  In practice
+             * this doesn't matter anyway, because png_inflate will call inflate
+             * with Z_FINISH in almost all cases, so the window will not be
+             * maintained.
+             */
+            if (inflateReset(&png_ptr->zstream) == Z_OK)
+            {
+               /* Because of the limit checks above we know that the new,
+                * expanded, size will fit in a size_t (let alone an
+                * png_alloc_size_t).  Use png_malloc_base here to avoid an
+                * extra OOM message.
+                */
+               png_alloc_size_t new_size = *newlength;
+               png_alloc_size_t buffer_size = prefix_size + new_size +
+                   (terminate != 0);
+               png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
+                   buffer_size));
+
+               if (text != NULL)
+               {
+                  memset(text, 0, buffer_size);
+
+                  ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
+                      png_ptr->read_buffer + prefix_size, &lzsize,
+                      text + prefix_size, newlength);
+
+                  if (ret == Z_STREAM_END)
+                  {
+                     if (new_size == *newlength)
+                     {
+                        if (terminate != 0)
+                           text[prefix_size + *newlength] = 0;
+
+                        if (prefix_size > 0)
+                           memcpy(text, png_ptr->read_buffer, prefix_size);
+
+                        {
+                           png_bytep old_ptr = png_ptr->read_buffer;
+
+                           png_ptr->read_buffer = text;
+                           png_ptr->read_buffer_size = buffer_size;
+                           text = old_ptr; /* freed below */
+                        }
+                     }
+
+                     else
+                     {
+                        /* The size changed on the second read, there can be no
+                         * guarantee that anything is correct at this point.
+                         * The 'msg' pointer has been set to "unexpected end of
+                         * LZ stream", which is fine, but return an error code
+                         * that the caller won't accept.
+                         */
+                        ret = PNG_UNEXPECTED_ZLIB_RETURN;
+                     }
+                  }
+
+                  else if (ret == Z_OK)
+                     ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
+
+                  /* Free the text pointer (this is the old read_buffer on
+                   * success)
+                   */
+                  png_free(png_ptr, text);
+
+                  /* This really is very benign, but it's still an error because
+                   * the extra space may otherwise be used as a Trojan Horse.
+                   */
+                  if (ret == Z_STREAM_END &&
+                      chunklength - prefix_size != lzsize)
+                     png_chunk_benign_error(png_ptr, "extra compressed data");
+               }
+
+               else
+               {
+                  /* Out of memory allocating the buffer */
+                  ret = Z_MEM_ERROR;
+                  png_zstream_error(png_ptr, Z_MEM_ERROR);
+               }
+            }
+
+            else
+            {
+               /* inflateReset failed, store the error message */
+               png_zstream_error(png_ptr, ret);
+               ret = PNG_UNEXPECTED_ZLIB_RETURN;
+            }
+         }
+
+         else if (ret == Z_OK)
+            ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+         /* Release the claimed stream */
+         png_ptr->zowner = 0;
+      }
+
+      else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
+         ret = PNG_UNEXPECTED_ZLIB_RETURN;
+
+      return ret;
+   }
+
+   else
+   {
+      /* Application/configuration limits exceeded */
+      png_zstream_error(png_ptr, Z_MEM_ERROR);
+      return Z_MEM_ERROR;
+   }
+}
+#endif /* READ_zTXt || READ_iTXt */
+#endif /* READ_COMPRESSED_TEXT */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+/* Perform a partial read and decompress, producing 'avail_out' bytes and
+ * reading from the current chunk as required.
+ */
+static int
+png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
+    png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
+    int finish)
+{
+   if (png_ptr->zowner == png_ptr->chunk_name)
+   {
+      int ret;
+
+      /* next_in and avail_in must have been initialized by the caller. */
+      png_ptr->zstream.next_out = next_out;
+      png_ptr->zstream.avail_out = 0; /* set in the loop */
+
+      do
+      {
+         if (png_ptr->zstream.avail_in == 0)
+         {
+            if (read_size > *chunk_bytes)
+               read_size = (uInt)*chunk_bytes;
+            *chunk_bytes -= read_size;
+
+            if (read_size > 0)
+               png_crc_read(png_ptr, read_buffer, read_size);
+
+            png_ptr->zstream.next_in = read_buffer;
+            png_ptr->zstream.avail_in = read_size;
+         }
+
+         if (png_ptr->zstream.avail_out == 0)
+         {
+            uInt avail = ZLIB_IO_MAX;
+            if (avail > *out_size)
+               avail = (uInt)*out_size;
+            *out_size -= avail;
+
+            png_ptr->zstream.avail_out = avail;
+         }
+
+         /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
+          * the available output is produced; this allows reading of truncated
+          * streams.
+          */
+         ret = PNG_INFLATE(png_ptr, *chunk_bytes > 0 ?
+             Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
+      }
+      while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
+
+      *out_size += png_ptr->zstream.avail_out;
+      png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
+
+      /* Ensure the error message pointer is always set: */
+      png_zstream_error(png_ptr, ret);
+      return ret;
+   }
+
+   else
+   {
+      png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
+      return Z_STREAM_ERROR;
+   }
+}
+#endif /* READ_iCCP */
+
+/* Read and check the IDHR chunk */
+
+void /* PRIVATE */
+png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte buf[13];
+   png_uint_32 width, height;
+   int bit_depth, color_type, compression_type, filter_type;
+   int interlace_type;
+
+   png_debug(1, "in png_handle_IHDR");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) != 0)
+      png_chunk_error(png_ptr, "out of place");
+
+   /* Check the length */
+   if (length != 13)
+      png_chunk_error(png_ptr, "invalid");
+
+   png_ptr->mode |= PNG_HAVE_IHDR;
+
+   png_crc_read(png_ptr, buf, 13);
+   png_crc_finish(png_ptr, 0);
+
+   width = png_get_uint_31(png_ptr, buf);
+   height = png_get_uint_31(png_ptr, buf + 4);
+   bit_depth = buf[8];
+   color_type = buf[9];
+   compression_type = buf[10];
+   filter_type = buf[11];
+   interlace_type = buf[12];
+
+   /* Set internal variables */
+   png_ptr->width = width;
+   png_ptr->height = height;
+   png_ptr->bit_depth = (png_byte)bit_depth;
+   png_ptr->interlaced = (png_byte)interlace_type;
+   png_ptr->color_type = (png_byte)color_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_ptr->filter_type = (png_byte)filter_type;
+#endif
+   png_ptr->compression_type = (png_byte)compression_type;
+
+   /* Find number of channels */
+   switch (png_ptr->color_type)
+   {
+      default: /* invalid, png_set_IHDR calls png_error */
+      case PNG_COLOR_TYPE_GRAY:
+      case PNG_COLOR_TYPE_PALETTE:
+         png_ptr->channels = 1;
+         break;
+
+      case PNG_COLOR_TYPE_RGB:
+         png_ptr->channels = 3;
+         break;
+
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         png_ptr->channels = 2;
+         break;
+
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+         png_ptr->channels = 4;
+         break;
+   }
+
+   /* Set up other useful info */
+   png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels);
+   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+   png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
+   png_debug1(3, "channels = %d", png_ptr->channels);
+   png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
+   png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+       color_type, interlace_type, compression_type, filter_type);
+}
+
+/* Read and check the palette */
+void /* PRIVATE */
+png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_color palette[PNG_MAX_PALETTE_LENGTH];
+   int max_palette_length, num, i;
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   png_colorp pal_ptr;
+#endif
+
+   png_debug(1, "in png_handle_PLTE");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   /* Moved to before the 'after IDAT' check below because otherwise duplicate
+    * PLTE chunks are potentially ignored (the spec says there shall not be more
+    * than one PLTE, the error is not treated as benign, so this check trumps
+    * the requirement that PLTE appears before IDAT.)
+    */
+   else if ((png_ptr->mode & PNG_HAVE_PLTE) != 0)
+      png_chunk_error(png_ptr, "duplicate");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      /* This is benign because the non-benign error happened before, when an
+       * IDAT was encountered in a color-mapped image with no PLTE.
+       */
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   png_ptr->mode |= PNG_HAVE_PLTE;
+
+   if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
+      return;
+   }
+
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+   if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+#endif
+
+   if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
+   {
+      png_crc_finish(png_ptr, length);
+
+      if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+         png_chunk_benign_error(png_ptr, "invalid");
+
+      else
+         png_chunk_error(png_ptr, "invalid");
+
+      return;
+   }
+
+   /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */
+   num = (int)length / 3;
+
+   /* If the palette has 256 or fewer entries but is too large for the bit
+    * depth, we don't issue an error, to preserve the behavior of previous
+    * libpng versions. We silently truncate the unused extra palette entries
+    * here.
+    */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      max_palette_length = (1 << png_ptr->bit_depth);
+   else
+      max_palette_length = PNG_MAX_PALETTE_LENGTH;
+
+   if (num > max_palette_length)
+      num = max_palette_length;
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
+   {
+      png_byte buf[3];
+
+      png_crc_read(png_ptr, buf, 3);
+      pal_ptr->red = buf[0];
+      pal_ptr->green = buf[1];
+      pal_ptr->blue = buf[2];
+   }
+#else
+   for (i = 0; i < num; i++)
+   {
+      png_byte buf[3];
+
+      png_crc_read(png_ptr, buf, 3);
+      /* Don't depend upon png_color being any order */
+      palette[i].red = buf[0];
+      palette[i].green = buf[1];
+      palette[i].blue = buf[2];
+   }
+#endif
+
+   /* If we actually need the PLTE chunk (ie for a paletted image), we do
+    * whatever the normal CRC configuration tells us.  However, if we
+    * have an RGB image, the PLTE can be considered ancillary, so
+    * we will act as though it is.
+    */
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#endif
+   {
+      png_crc_finish(png_ptr, (png_uint_32) (length - (unsigned int)num * 3));
+   }
+
+#ifndef PNG_READ_OPT_PLTE_SUPPORTED
+   else if (png_crc_error(png_ptr) != 0)  /* Only if we have a CRC error */
+   {
+      /* If we don't want to use the data from an ancillary chunk,
+       * we have two options: an error abort, or a warning and we
+       * ignore the data in this chunk (which should be OK, since
+       * it's considered ancillary for a RGB or RGBA image).
+       *
+       * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the
+       * chunk type to determine whether to check the ancillary or the critical
+       * flags.
+       */
+      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE) == 0)
+      {
+         if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0)
+            return;
+
+         else
+            png_chunk_error(png_ptr, "CRC error");
+      }
+
+      /* Otherwise, we (optionally) emit a warning and use the chunk. */
+      else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0)
+         png_chunk_warning(png_ptr, "CRC error");
+   }
+#endif
+
+   /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its
+    * own copy of the palette.  This has the side effect that when png_start_row
+    * is called (this happens after any call to png_read_update_info) the
+    * info_ptr palette gets changed.  This is extremely unexpected and
+    * confusing.
+    *
+    * Fix this by not sharing the palette in this way.
+    */
+   png_set_PLTE(png_ptr, info_ptr, palette, num);
+
+   /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before
+    * IDAT.  Prior to 1.6.0 this was not checked; instead the code merely
+    * checked the apparent validity of a tRNS chunk inserted before PLTE on a
+    * palette PNG.  1.6.0 attempts to rigorously follow the standard and
+    * therefore does a benign error if the erroneous condition is detected *and*
+    * cancels the tRNS if the benign error returns.  The alternative is to
+    * amend the standard since it would be rather hypocritical of the standards
+    * maintainers to ignore it.
+    */
+#ifdef PNG_READ_tRNS_SUPPORTED
+   if (png_ptr->num_trans > 0 ||
+       (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
+   {
+      /* Cancel this because otherwise it would be used if the transforms
+       * require it.  Don't cancel the 'valid' flag because this would prevent
+       * detection of duplicate chunks.
+       */
+      png_ptr->num_trans = 0;
+
+      if (info_ptr != NULL)
+         info_ptr->num_trans = 0;
+
+      png_chunk_benign_error(png_ptr, "tRNS must be after");
+   }
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
+      png_chunk_benign_error(png_ptr, "hIST must be after");
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
+      png_chunk_benign_error(png_ptr, "bKGD must be after");
+#endif
+}
+
+void /* PRIVATE */
+png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_debug(1, "in png_handle_IEND");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0 ||
+       (png_ptr->mode & PNG_HAVE_IDAT) == 0)
+      png_chunk_error(png_ptr, "out of place");
+
+   png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
+
+   png_crc_finish(png_ptr, length);
+
+   if (length != 0)
+      png_chunk_benign_error(png_ptr, "invalid");
+
+   PNG_UNUSED(info_ptr)
+}
+
+#ifdef PNG_READ_gAMA_SUPPORTED
+void /* PRIVATE */
+png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_fixed_point igamma;
+   png_byte buf[4];
+
+   png_debug(1, "in png_handle_gAMA");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   if (length != 4)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, buf, 4);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   igamma = png_get_fixed_point(NULL, buf);
+
+   png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
+   png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif
+
+#ifdef PNG_READ_sBIT_SUPPORTED
+void /* PRIVATE */
+png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   unsigned int truelen, i;
+   png_byte sample_depth;
+   png_byte buf[4];
+
+   png_debug(1, "in png_handle_sBIT");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      truelen = 3;
+      sample_depth = 8;
+   }
+
+   else
+   {
+      truelen = png_ptr->channels;
+      sample_depth = png_ptr->bit_depth;
+   }
+
+   if (length != truelen || length > 4)
+   {
+      png_chunk_benign_error(png_ptr, "invalid");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
+   buf[0] = buf[1] = buf[2] = buf[3] = sample_depth;
+   png_crc_read(png_ptr, buf, truelen);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   for (i=0; i<truelen; ++i)
+   {
+      if (buf[i] == 0 || buf[i] > sample_depth)
+      {
+         png_chunk_benign_error(png_ptr, "invalid");
+         return;
+      }
+   }
+
+   if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[1];
+      png_ptr->sig_bit.blue = buf[2];
+      png_ptr->sig_bit.alpha = buf[3];
+   }
+
+   else
+   {
+      png_ptr->sig_bit.gray = buf[0];
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[0];
+      png_ptr->sig_bit.blue = buf[0];
+      png_ptr->sig_bit.alpha = buf[1];
+   }
+
+   png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
+}
+#endif
+
+#ifdef PNG_READ_cHRM_SUPPORTED
+void /* PRIVATE */
+png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte buf[32];
+   png_xy xy;
+
+   png_debug(1, "in png_handle_cHRM");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   if (length != 32)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, buf, 32);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   xy.whitex = png_get_fixed_point(NULL, buf);
+   xy.whitey = png_get_fixed_point(NULL, buf + 4);
+   xy.redx   = png_get_fixed_point(NULL, buf + 8);
+   xy.redy   = png_get_fixed_point(NULL, buf + 12);
+   xy.greenx = png_get_fixed_point(NULL, buf + 16);
+   xy.greeny = png_get_fixed_point(NULL, buf + 20);
+   xy.bluex  = png_get_fixed_point(NULL, buf + 24);
+   xy.bluey  = png_get_fixed_point(NULL, buf + 28);
+
+   if (xy.whitex == PNG_FIXED_ERROR ||
+       xy.whitey == PNG_FIXED_ERROR ||
+       xy.redx   == PNG_FIXED_ERROR ||
+       xy.redy   == PNG_FIXED_ERROR ||
+       xy.greenx == PNG_FIXED_ERROR ||
+       xy.greeny == PNG_FIXED_ERROR ||
+       xy.bluex  == PNG_FIXED_ERROR ||
+       xy.bluey  == PNG_FIXED_ERROR)
+   {
+      png_chunk_benign_error(png_ptr, "invalid values");
+      return;
+   }
+
+   /* If a colorspace error has already been output skip this chunk */
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+      return;
+
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0)
+   {
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+      png_colorspace_sync(png_ptr, info_ptr);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+   (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy,
+       1/*prefer cHRM values*/);
+   png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif
+
+#ifdef PNG_READ_sRGB_SUPPORTED
+void /* PRIVATE */
+png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte intent;
+
+   png_debug(1, "in png_handle_sRGB");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   if (length != 1)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, &intent, 1);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   /* If a colorspace error has already been output skip this chunk */
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+      return;
+
+   /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
+    * this.
+    */
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) != 0)
+   {
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+      png_colorspace_sync(png_ptr, info_ptr);
+      png_chunk_benign_error(png_ptr, "too many profiles");
+      return;
+   }
+
+   (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
+   png_colorspace_sync(png_ptr, info_ptr);
+}
+#endif /* READ_sRGB */
+
+#ifdef PNG_READ_iCCP_SUPPORTED
+void /* PRIVATE */
+png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle profiles that are > 64K under DOS */
+{
+   png_const_charp errmsg = NULL; /* error message output, or no error */
+   int finished = 0; /* crc checked */
+
+   png_debug(1, "in png_handle_iCCP");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   /* Consistent with all the above colorspace handling an obviously *invalid*
+    * chunk is just ignored, so does not invalidate the color space.  An
+    * alternative is to set the 'invalid' flags at the start of this routine
+    * and only clear them in they were not set before and all the tests pass.
+    */
+
+   /* The keyword must be at least one character and there is a
+    * terminator (0) byte and the compression method byte, and the
+    * 'zlib' datastream is at least 11 bytes.
+    */
+   if (length < 14)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "too short");
+      return;
+   }
+
+   /* If a colorspace error has already been output skip this chunk */
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
+   /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
+    * this.
+    */
+   if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0)
+   {
+      uInt read_length, keyword_length;
+      char keyword[81];
+
+      /* Find the keyword; the keyword plus separator and compression method
+       * bytes can be at most 81 characters long.
+       */
+      read_length = 81; /* maximum */
+      if (read_length > length)
+         read_length = (uInt)length;
+
+      png_crc_read(png_ptr, (png_bytep)keyword, read_length);
+      length -= read_length;
+
+      /* The minimum 'zlib' stream is assumed to be just the 2 byte header,
+       * 5 bytes minimum 'deflate' stream, and the 4 byte checksum.
+       */
+      if (length < 11)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "too short");
+         return;
+      }
+
+      keyword_length = 0;
+      while (keyword_length < 80 && keyword_length < read_length &&
+         keyword[keyword_length] != 0)
+         ++keyword_length;
+
+      /* TODO: make the keyword checking common */
+      if (keyword_length >= 1 && keyword_length <= 79)
+      {
+         /* We only understand '0' compression - deflate - so if we get a
+          * different value we can't safely decode the chunk.
+          */
+         if (keyword_length+1 < read_length &&
+            keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
+         {
+            read_length -= keyword_length+2;
+
+            if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
+            {
+               Byte profile_header[132]={0};
+               Byte local_buffer[PNG_INFLATE_BUF_SIZE];
+               png_alloc_size_t size = (sizeof profile_header);
+
+               png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
+               png_ptr->zstream.avail_in = read_length;
+               (void)png_inflate_read(png_ptr, local_buffer,
+                   (sizeof local_buffer), &length, profile_header, &size,
+                   0/*finish: don't, because the output is too small*/);
+
+               if (size == 0)
+               {
+                  /* We have the ICC profile header; do the basic header checks.
+                   */
+                  const png_uint_32 profile_length =
+                     png_get_uint_32(profile_header);
+
+                  if (png_icc_check_length(png_ptr, &png_ptr->colorspace,
+                      keyword, profile_length) != 0)
+                  {
+                     /* The length is apparently ok, so we can check the 132
+                      * byte header.
+                      */
+                     if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
+                         keyword, profile_length, profile_header,
+                         png_ptr->color_type) != 0)
+                     {
+                        /* Now read the tag table; a variable size buffer is
+                         * needed at this point, allocate one for the whole
+                         * profile.  The header check has already validated
+                         * that none of this stuff will overflow.
+                         */
+                        const png_uint_32 tag_count = png_get_uint_32(
+                            profile_header+128);
+                        png_bytep profile = png_read_buffer(png_ptr,
+                            profile_length, 2/*silent*/);
+
+                        if (profile != NULL)
+                        {
+                           memcpy(profile, profile_header,
+                               (sizeof profile_header));
+
+                           size = 12 * tag_count;
+
+                           (void)png_inflate_read(png_ptr, local_buffer,
+                               (sizeof local_buffer), &length,
+                               profile + (sizeof profile_header), &size, 0);
+
+                           /* Still expect a buffer error because we expect
+                            * there to be some tag data!
+                            */
+                           if (size == 0)
+                           {
+                              if (png_icc_check_tag_table(png_ptr,
+                                  &png_ptr->colorspace, keyword, profile_length,
+                                  profile) != 0)
+                              {
+                                 /* The profile has been validated for basic
+                                  * security issues, so read the whole thing in.
+                                  */
+                                 size = profile_length - (sizeof profile_header)
+                                     - 12 * tag_count;
+
+                                 (void)png_inflate_read(png_ptr, local_buffer,
+                                     (sizeof local_buffer), &length,
+                                     profile + (sizeof profile_header) +
+                                     12 * tag_count, &size, 1/*finish*/);
+
+                                 if (length > 0 && !(png_ptr->flags &
+                                     PNG_FLAG_BENIGN_ERRORS_WARN))
+                                    errmsg = "extra compressed data";
+
+                                 /* But otherwise allow extra data: */
+                                 else if (size == 0)
+                                 {
+                                    if (length > 0)
+                                    {
+                                       /* This can be handled completely, so
+                                        * keep going.
+                                        */
+                                       png_chunk_warning(png_ptr,
+                                           "extra compressed data");
+                                    }
+
+                                    png_crc_finish(png_ptr, length);
+                                    finished = 1;
+
+# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
+                                    /* Check for a match against sRGB */
+                                    png_icc_set_sRGB(png_ptr,
+                                        &png_ptr->colorspace, profile,
+                                        png_ptr->zstream.adler);
+# endif
+
+                                    /* Steal the profile for info_ptr. */
+                                    if (info_ptr != NULL)
+                                    {
+                                       png_free_data(png_ptr, info_ptr,
+                                           PNG_FREE_ICCP, 0);
+
+                                       info_ptr->iccp_name = png_voidcast(char*,
+                                           png_malloc_base(png_ptr,
+                                           keyword_length+1));
+                                       if (info_ptr->iccp_name != NULL)
+                                       {
+                                          memcpy(info_ptr->iccp_name, keyword,
+                                              keyword_length+1);
+                                          info_ptr->iccp_proflen =
+                                              profile_length;
+                                          info_ptr->iccp_profile = profile;
+                                          png_ptr->read_buffer = NULL; /*steal*/
+                                          info_ptr->free_me |= PNG_FREE_ICCP;
+                                          info_ptr->valid |= PNG_INFO_iCCP;
+                                       }
+
+                                       else
+                                       {
+                                          png_ptr->colorspace.flags |=
+                                             PNG_COLORSPACE_INVALID;
+                                          errmsg = "out of memory";
+                                       }
+                                    }
+
+                                    /* else the profile remains in the read
+                                     * buffer which gets reused for subsequent
+                                     * chunks.
+                                     */
+
+                                    if (info_ptr != NULL)
+                                       png_colorspace_sync(png_ptr, info_ptr);
+
+                                    if (errmsg == NULL)
+                                    {
+                                       png_ptr->zowner = 0;
+                                       return;
+                                    }
+                                 }
+                                 if (errmsg == NULL)
+                                    errmsg = png_ptr->zstream.msg;
+                              }
+                              /* else png_icc_check_tag_table output an error */
+                           }
+                           else /* profile truncated */
+                              errmsg = png_ptr->zstream.msg;
+                        }
+
+                        else
+                           errmsg = "out of memory";
+                     }
+
+                     /* else png_icc_check_header output an error */
+                  }
+
+                  /* else png_icc_check_length output an error */
+               }
+
+               else /* profile truncated */
+                  errmsg = png_ptr->zstream.msg;
+
+               /* Release the stream */
+               png_ptr->zowner = 0;
+            }
+
+            else /* png_inflate_claim failed */
+               errmsg = png_ptr->zstream.msg;
+         }
+
+         else
+            errmsg = "bad compression method"; /* or missing */
+      }
+
+      else
+         errmsg = "bad keyword";
+   }
+
+   else
+      errmsg = "too many profiles";
+
+   /* Failure: the reason is in 'errmsg' */
+   if (finished == 0)
+      png_crc_finish(png_ptr, length);
+
+   png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
+   png_colorspace_sync(png_ptr, info_ptr);
+   if (errmsg != NULL) /* else already output */
+      png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif /* READ_iCCP */
+
+#ifdef PNG_READ_sPLT_SUPPORTED
+void /* PRIVATE */
+png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+{
+   png_bytep entry_start, buffer;
+   png_sPLT_t new_palette;
+   png_sPLT_entryp pp;
+   png_uint_32 data_length;
+   int entry_size, i;
+   png_uint_32 skip = 0;
+   png_uint_32 dl;
+   png_size_t max_dl;
+
+   png_debug(1, "in png_handle_sPLT");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_warning(png_ptr, "No space in chunk cache for sPLT");
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+   }
+#endif
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > 65535U)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "too large to fit in memory");
+      return;
+   }
+#endif
+
+   buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+   if (buffer == NULL)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+
+   /* WARNING: this may break if size_t is less than 32 bits; it is assumed
+    * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
+    * potential breakage point if the types in pngconf.h aren't exactly right.
+    */
+   png_crc_read(png_ptr, buffer, length);
+
+   if (png_crc_finish(png_ptr, skip) != 0)
+      return;
+
+   buffer[length] = 0;
+
+   for (entry_start = buffer; *entry_start; entry_start++)
+      /* Empty loop to find end of name */ ;
+
+   ++entry_start;
+
+   /* A sample depth should follow the separator, and we should be on it  */
+   if (length < 2U || entry_start > buffer + (length - 2U))
+   {
+      png_warning(png_ptr, "malformed sPLT chunk");
+      return;
+   }
+
+   new_palette.depth = *entry_start++;
+   entry_size = (new_palette.depth == 8 ? 6 : 10);
+   /* This must fit in a png_uint_32 because it is derived from the original
+    * chunk data length.
+    */
+   data_length = length - (png_uint_32)(entry_start - buffer);
+
+   /* Integrity-check the data length */
+   if ((data_length % (unsigned int)entry_size) != 0)
+   {
+      png_warning(png_ptr, "sPLT chunk has bad length");
+      return;
+   }
+
+   dl = (png_uint_32)(data_length / (unsigned int)entry_size);
+   max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
+
+   if (dl > max_dl)
+   {
+      png_warning(png_ptr, "sPLT chunk too long");
+      return;
+   }
+
+   new_palette.nentries = (png_int_32)(data_length / (unsigned int)entry_size);
+
+   new_palette.entries = (png_sPLT_entryp)png_malloc_warn(png_ptr,
+       (png_alloc_size_t) new_palette.nentries * (sizeof (png_sPLT_entry)));
+
+   if (new_palette.entries == NULL)
+   {
+      png_warning(png_ptr, "sPLT chunk requires too much memory");
+      return;
+   }
+
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (i = 0; i < new_palette.nentries; i++)
+   {
+      pp = new_palette.entries + i;
+
+      if (new_palette.depth == 8)
+      {
+         pp->red = *entry_start++;
+         pp->green = *entry_start++;
+         pp->blue = *entry_start++;
+         pp->alpha = *entry_start++;
+      }
+
+      else
+      {
+         pp->red   = png_get_uint_16(entry_start); entry_start += 2;
+         pp->green = png_get_uint_16(entry_start); entry_start += 2;
+         pp->blue  = png_get_uint_16(entry_start); entry_start += 2;
+         pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
+      }
+
+      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
+   }
+#else
+   pp = new_palette.entries;
+
+   for (i = 0; i < new_palette.nentries; i++)
+   {
+
+      if (new_palette.depth == 8)
+      {
+         pp[i].red   = *entry_start++;
+         pp[i].green = *entry_start++;
+         pp[i].blue  = *entry_start++;
+         pp[i].alpha = *entry_start++;
+      }
+
+      else
+      {
+         pp[i].red   = png_get_uint_16(entry_start); entry_start += 2;
+         pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
+         pp[i].blue  = png_get_uint_16(entry_start); entry_start += 2;
+         pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
+      }
+
+      pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
+   }
+#endif
+
+   /* Discard all chunk data except the name and stash that */
+   new_palette.name = (png_charp)buffer;
+
+   png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
+
+   png_free(png_ptr, new_palette.entries);
+}
+#endif /* READ_sPLT */
+
+#ifdef PNG_READ_tRNS_SUPPORTED
+void /* PRIVATE */
+png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
+
+   png_debug(1, "in png_handle_tRNS");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      png_byte buf[2];
+
+      if (length != 2)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "invalid");
+         return;
+      }
+
+      png_crc_read(png_ptr, buf, 2);
+      png_ptr->num_trans = 1;
+      png_ptr->trans_color.gray = png_get_uint_16(buf);
+   }
+
+   else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      png_byte buf[6];
+
+      if (length != 6)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "invalid");
+         return;
+      }
+
+      png_crc_read(png_ptr, buf, length);
+      png_ptr->num_trans = 1;
+      png_ptr->trans_color.red = png_get_uint_16(buf);
+      png_ptr->trans_color.green = png_get_uint_16(buf + 2);
+      png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
+   }
+
+   else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if ((png_ptr->mode & PNG_HAVE_PLTE) == 0)
+      {
+         /* TODO: is this actually an error in the ISO spec? */
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "out of place");
+         return;
+      }
+
+      if (length > (unsigned int) png_ptr->num_palette ||
+         length > (unsigned int) PNG_MAX_PALETTE_LENGTH ||
+         length == 0)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "invalid");
+         return;
+      }
+
+      png_crc_read(png_ptr, readbuf, length);
+      png_ptr->num_trans = (png_uint_16)length;
+   }
+
+   else
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid with alpha channel");
+      return;
+   }
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+   {
+      png_ptr->num_trans = 0;
+      return;
+   }
+
+   /* TODO: this is a horrible side effect in the palette case because the
+    * png_struct ends up with a pointer to the tRNS buffer owned by the
+    * png_info.  Fix this.
+    */
+   png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
+       &(png_ptr->trans_color));
+}
+#endif
+
+#ifdef PNG_READ_bKGD_SUPPORTED
+void /* PRIVATE */
+png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   unsigned int truelen;
+   png_byte buf[6];
+   png_color_16 background;
+
+   png_debug(1, "in png_handle_bKGD");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 ||
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+       (png_ptr->mode & PNG_HAVE_PLTE) == 0))
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      truelen = 1;
+
+   else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      truelen = 6;
+
+   else
+      truelen = 2;
+
+   if (length != truelen)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, buf, truelen);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   /* We convert the index value into RGB components so that we can allow
+    * arbitrary RGB values for background when we have transparency, and
+    * so it is easy to determine the RGB values of the background color
+    * from the info_ptr struct.
+    */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      background.index = buf[0];
+
+      if (info_ptr != NULL && info_ptr->num_palette != 0)
+      {
+         if (buf[0] >= info_ptr->num_palette)
+         {
+            png_chunk_benign_error(png_ptr, "invalid index");
+            return;
+         }
+
+         background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+         background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+         background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+      }
+
+      else
+         background.red = background.green = background.blue = 0;
+
+      background.gray = 0;
+   }
+
+   else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */
+   {
+      background.index = 0;
+      background.red =
+      background.green =
+      background.blue =
+      background.gray = png_get_uint_16(buf);
+   }
+
+   else
+   {
+      background.index = 0;
+      background.red = png_get_uint_16(buf);
+      background.green = png_get_uint_16(buf + 2);
+      background.blue = png_get_uint_16(buf + 4);
+      background.gray = 0;
+   }
+
+   png_set_bKGD(png_ptr, info_ptr, &background);
+}
+#endif
+
+#ifdef PNG_READ_eXIf_SUPPORTED
+void /* PRIVATE */
+png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   unsigned int i;
+
+   png_debug(1, "in png_handle_eXIf");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   if (length < 2)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "too short");
+      return;
+   }
+
+   else if (info_ptr == NULL || (info_ptr->valid & PNG_INFO_eXIf) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   info_ptr->free_me |= PNG_FREE_EXIF;
+
+   info_ptr->eXIf_buf = png_voidcast(png_bytep,
+             png_malloc_warn(png_ptr, length));
+
+   if (info_ptr->eXIf_buf == NULL)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+   for (i = 0; i < length; i++)
+   {
+      png_byte buf[1];
+      png_crc_read(png_ptr, buf, 1);
+      info_ptr->eXIf_buf[i] = buf[0];
+      if (i == 1 && buf[0] != 'M' && buf[0] != 'I'
+                 && info_ptr->eXIf_buf[0] != buf[0])
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "incorrect byte-order specifier");
+         png_free(png_ptr, info_ptr->eXIf_buf);
+         info_ptr->eXIf_buf = NULL;
+         return;
+      }
+   }
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf);
+
+   png_free(png_ptr, info_ptr->eXIf_buf);
+   info_ptr->eXIf_buf = NULL;
+}
+#endif
+
+#ifdef PNG_READ_hIST_SUPPORTED
+void /* PRIVATE */
+png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   unsigned int num, i;
+   png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
+
+   png_debug(1, "in png_handle_hIST");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 ||
+       (png_ptr->mode & PNG_HAVE_PLTE) == 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   num = length / 2 ;
+
+   if (num != (unsigned int) png_ptr->num_palette ||
+       num > (unsigned int) PNG_MAX_PALETTE_LENGTH)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   for (i = 0; i < num; i++)
+   {
+      png_byte buf[2];
+
+      png_crc_read(png_ptr, buf, 2);
+      readbuf[i] = png_get_uint_16(buf);
+   }
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   png_set_hIST(png_ptr, info_ptr, readbuf);
+}
+#endif
+
+#ifdef PNG_READ_pHYs_SUPPORTED
+void /* PRIVATE */
+png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte buf[9];
+   png_uint_32 res_x, res_y;
+   int unit_type;
+
+   png_debug(1, "in png_handle_pHYs");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   if (length != 9)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, buf, 9);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   res_x = png_get_uint_32(buf);
+   res_y = png_get_uint_32(buf + 4);
+   unit_type = buf[8];
+   png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
+}
+#endif
+
+#ifdef PNG_READ_oFFs_SUPPORTED
+void /* PRIVATE */
+png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte buf[9];
+   png_int_32 offset_x, offset_y;
+   int unit_type;
+
+   png_debug(1, "in png_handle_oFFs");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   if (length != 9)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, buf, 9);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   offset_x = png_get_int_32(buf);
+   offset_y = png_get_int_32(buf + 4);
+   unit_type = buf[8];
+   png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
+}
+#endif
+
+#ifdef PNG_READ_pCAL_SUPPORTED
+/* Read the pCAL chunk (described in the PNG Extensions document) */
+void /* PRIVATE */
+png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_int_32 X0, X1;
+   png_byte type, nparams;
+   png_bytep buffer, buf, units, endptr;
+   png_charpp params;
+   int i;
+
+   png_debug(1, "in png_handle_pCAL");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
+       length + 1);
+
+   buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+   if (buffer == NULL)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+   png_crc_read(png_ptr, buffer, length);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   buffer[length] = 0; /* Null terminate the last string */
+
+   png_debug(3, "Finding end of pCAL purpose string");
+   for (buf = buffer; *buf; buf++)
+      /* Empty loop */ ;
+
+   endptr = buffer + length;
+
+   /* We need to have at least 12 bytes after the purpose string
+    * in order to get the parameter information.
+    */
+   if (endptr - buf <= 12)
+   {
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
+   X0 = png_get_int_32((png_bytep)buf+1);
+   X1 = png_get_int_32((png_bytep)buf+5);
+   type = buf[9];
+   nparams = buf[10];
+   units = buf + 11;
+
+   png_debug(3, "Checking pCAL equation type and number of parameters");
+   /* Check that we have the right number of parameters for known
+    * equation types.
+    */
+   if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
+       (type == PNG_EQUATION_BASE_E && nparams != 3) ||
+       (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
+       (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
+   {
+      png_chunk_benign_error(png_ptr, "invalid parameter count");
+      return;
+   }
+
+   else if (type >= PNG_EQUATION_LAST)
+   {
+      png_chunk_benign_error(png_ptr, "unrecognized equation type");
+   }
+
+   for (buf = units; *buf; buf++)
+      /* Empty loop to move past the units string. */ ;
+
+   png_debug(3, "Allocating pCAL parameters array");
+
+   params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+       nparams * (sizeof (png_charp))));
+
+   if (params == NULL)
+   {
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+   /* Get pointers to the start of each parameter string. */
+   for (i = 0; i < nparams; i++)
+   {
+      buf++; /* Skip the null string terminator from previous parameter. */
+
+      png_debug1(3, "Reading pCAL parameter %d", i);
+
+      for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
+         /* Empty loop to move past each parameter string */ ;
+
+      /* Make sure we haven't run out of data yet */
+      if (buf > endptr)
+      {
+         png_free(png_ptr, params);
+         png_chunk_benign_error(png_ptr, "invalid data");
+         return;
+      }
+   }
+
+   png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
+       (png_charp)units, params);
+
+   png_free(png_ptr, params);
+}
+#endif
+
+#ifdef PNG_READ_sCAL_SUPPORTED
+/* Read the sCAL chunk */
+void /* PRIVATE */
+png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_bytep buffer;
+   png_size_t i;
+   int state;
+
+   png_debug(1, "in png_handle_sCAL");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of place");
+      return;
+   }
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   /* Need unit type, width, \0, height: minimum 4 bytes */
+   else if (length < 4)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
+       length + 1);
+
+   buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
+
+   if (buffer == NULL)
+   {
+      png_chunk_benign_error(png_ptr, "out of memory");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
+   png_crc_read(png_ptr, buffer, length);
+   buffer[length] = 0; /* Null terminate the last string */
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   /* Validate the unit. */
+   if (buffer[0] != 1 && buffer[0] != 2)
+   {
+      png_chunk_benign_error(png_ptr, "invalid unit");
+      return;
+   }
+
+   /* Validate the ASCII numbers, need two ASCII numbers separated by
+    * a '\0' and they need to fit exactly in the chunk data.
+    */
+   i = 1;
+   state = 0;
+
+   if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 ||
+       i >= length || buffer[i++] != 0)
+      png_chunk_benign_error(png_ptr, "bad width format");
+
+   else if (PNG_FP_IS_POSITIVE(state) == 0)
+      png_chunk_benign_error(png_ptr, "non-positive width");
+
+   else
+   {
+      png_size_t heighti = i;
+
+      state = 0;
+      if (png_check_fp_number((png_const_charp)buffer, length,
+          &state, &i) == 0 || i != length)
+         png_chunk_benign_error(png_ptr, "bad height format");
+
+      else if (PNG_FP_IS_POSITIVE(state) == 0)
+         png_chunk_benign_error(png_ptr, "non-positive height");
+
+      else
+         /* This is the (only) success case. */
+         png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
+             (png_charp)buffer+1, (png_charp)buffer+heighti);
+   }
+}
+#endif
+
+#ifdef PNG_READ_tIME_SUPPORTED
+void /* PRIVATE */
+png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_byte buf[7];
+   png_time mod_time;
+
+   png_debug(1, "in png_handle_tIME");
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "duplicate");
+      return;
+   }
+
+   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+
+   if (length != 7)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "invalid");
+      return;
+   }
+
+   png_crc_read(png_ptr, buf, 7);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   mod_time.second = buf[6];
+   mod_time.minute = buf[5];
+   mod_time.hour = buf[4];
+   mod_time.day = buf[3];
+   mod_time.month = buf[2];
+   mod_time.year = png_get_uint_16(buf);
+
+   png_set_tIME(png_ptr, info_ptr, &mod_time);
+}
+#endif
+
+#ifdef PNG_READ_tEXt_SUPPORTED
+/* Note: this does not properly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_text  text_info;
+   png_bytep buffer;
+   png_charp key;
+   png_charp text;
+   png_uint_32 skip = 0;
+
+   png_debug(1, "in png_handle_tEXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "no space in chunk cache");
+         return;
+      }
+   }
+#endif
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (length > 65535U)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "too large to fit in memory");
+      return;
+   }
+#endif
+
+   buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
+
+   if (buffer == NULL)
+   {
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+   png_crc_read(png_ptr, buffer, length);
+
+   if (png_crc_finish(png_ptr, skip) != 0)
+      return;
+
+   key = (png_charp)buffer;
+   key[length] = 0;
+
+   for (text = key; *text; text++)
+      /* Empty loop to find end of key */ ;
+
+   if (text != key + length)
+      text++;
+
+   text_info.compression = PNG_TEXT_COMPRESSION_NONE;
+   text_info.key = key;
+   text_info.lang = NULL;
+   text_info.lang_key = NULL;
+   text_info.itxt_length = 0;
+   text_info.text = text;
+   text_info.text_length = strlen(text);
+
+   if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) != 0)
+      png_warning(png_ptr, "Insufficient memory to process text chunk");
+}
+#endif
+
+#ifdef PNG_READ_zTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_const_charp errmsg = NULL;
+   png_bytep       buffer;
+   png_uint_32     keyword_length;
+
+   png_debug(1, "in png_handle_zTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "no space in chunk cache");
+         return;
+      }
+   }
+#endif
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+
+   /* Note, "length" is sufficient here; we won't be adding
+    * a null terminator later.
+    */
+   buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
+
+   if (buffer == NULL)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+   png_crc_read(png_ptr, buffer, length);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   /* TODO: also check that the keyword contents match the spec! */
+   for (keyword_length = 0;
+      keyword_length < length && buffer[keyword_length] != 0;
+      ++keyword_length)
+      /* Empty loop to find end of name */ ;
+
+   if (keyword_length > 79 || keyword_length < 1)
+      errmsg = "bad keyword";
+
+   /* zTXt must have some LZ data after the keyword, although it may expand to
+    * zero bytes; we need a '\0' at the end of the keyword, the compression type
+    * then the LZ data:
+    */
+   else if (keyword_length + 3 > length)
+      errmsg = "truncated";
+
+   else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
+      errmsg = "unknown compression type";
+
+   else
+   {
+      png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
+
+      /* TODO: at present png_decompress_chunk imposes a single application
+       * level memory limit, this should be split to different values for iCCP
+       * and text chunks.
+       */
+      if (png_decompress_chunk(png_ptr, length, keyword_length+2,
+          &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+      {
+         png_text text;
+
+         if (png_ptr->read_buffer == NULL)
+           errmsg="Read failure in png_handle_zTXt";
+         else
+         {
+            /* It worked; png_ptr->read_buffer now looks like a tEXt chunk
+             * except for the extra compression type byte and the fact that
+             * it isn't necessarily '\0' terminated.
+             */
+            buffer = png_ptr->read_buffer;
+            buffer[uncompressed_length+(keyword_length+2)] = 0;
+
+            text.compression = PNG_TEXT_COMPRESSION_zTXt;
+            text.key = (png_charp)buffer;
+            text.text = (png_charp)(buffer + keyword_length+2);
+            text.text_length = uncompressed_length;
+            text.itxt_length = 0;
+            text.lang = NULL;
+            text.lang_key = NULL;
+
+            if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
+               errmsg = "insufficient memory";
+         }
+      }
+
+      else
+         errmsg = png_ptr->zstream.msg;
+   }
+
+   if (errmsg != NULL)
+      png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif
+
+#ifdef PNG_READ_iTXt_SUPPORTED
+/* Note: this does not correctly handle chunks that are > 64K under DOS */
+void /* PRIVATE */
+png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+   png_const_charp errmsg = NULL;
+   png_bytep buffer;
+   png_uint_32 prefix_length;
+
+   png_debug(1, "in png_handle_iTXt");
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_cache_max != 0)
+   {
+      if (png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         return;
+      }
+
+      if (--png_ptr->user_chunk_cache_max == 1)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "no space in chunk cache");
+         return;
+      }
+   }
+#endif
+
+   if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+      png_chunk_error(png_ptr, "missing IHDR");
+
+   if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
+      png_ptr->mode |= PNG_AFTER_IDAT;
+
+   buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
+
+   if (buffer == NULL)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
+   png_crc_read(png_ptr, buffer, length);
+
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   /* First the keyword. */
+   for (prefix_length=0;
+      prefix_length < length && buffer[prefix_length] != 0;
+      ++prefix_length)
+      /* Empty loop */ ;
+
+   /* Perform a basic check on the keyword length here. */
+   if (prefix_length > 79 || prefix_length < 1)
+      errmsg = "bad keyword";
+
+   /* Expect keyword, compression flag, compression type, language, translated
+    * keyword (both may be empty but are 0 terminated) then the text, which may
+    * be empty.
+    */
+   else if (prefix_length + 5 > length)
+      errmsg = "truncated";
+
+   else if (buffer[prefix_length+1] == 0 ||
+      (buffer[prefix_length+1] == 1 &&
+      buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
+   {
+      int compressed = buffer[prefix_length+1] != 0;
+      png_uint_32 language_offset, translated_keyword_offset;
+      png_alloc_size_t uncompressed_length = 0;
+
+      /* Now the language tag */
+      prefix_length += 3;
+      language_offset = prefix_length;
+
+      for (; prefix_length < length && buffer[prefix_length] != 0;
+         ++prefix_length)
+         /* Empty loop */ ;
+
+      /* WARNING: the length may be invalid here, this is checked below. */
+      translated_keyword_offset = ++prefix_length;
+
+      for (; prefix_length < length && buffer[prefix_length] != 0;
+         ++prefix_length)
+         /* Empty loop */ ;
+
+      /* prefix_length should now be at the trailing '\0' of the translated
+       * keyword, but it may already be over the end.  None of this arithmetic
+       * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
+       * systems the available allocation may overflow.
+       */
+      ++prefix_length;
+
+      if (compressed == 0 && prefix_length <= length)
+         uncompressed_length = length - prefix_length;
+
+      else if (compressed != 0 && prefix_length < length)
+      {
+         uncompressed_length = PNG_SIZE_MAX;
+
+         /* TODO: at present png_decompress_chunk imposes a single application
+          * level memory limit, this should be split to different values for
+          * iCCP and text chunks.
+          */
+         if (png_decompress_chunk(png_ptr, length, prefix_length,
+             &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
+            buffer = png_ptr->read_buffer;
+
+         else
+            errmsg = png_ptr->zstream.msg;
+      }
+
+      else
+         errmsg = "truncated";
+
+      if (errmsg == NULL)
+      {
+         png_text text;
+
+         buffer[uncompressed_length+prefix_length] = 0;
+
+         if (compressed == 0)
+            text.compression = PNG_ITXT_COMPRESSION_NONE;
+
+         else
+            text.compression = PNG_ITXT_COMPRESSION_zTXt;
+
+         text.key = (png_charp)buffer;
+         text.lang = (png_charp)buffer + language_offset;
+         text.lang_key = (png_charp)buffer + translated_keyword_offset;
+         text.text = (png_charp)buffer + prefix_length;
+         text.text_length = 0;
+         text.itxt_length = uncompressed_length;
+
+         if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
+            errmsg = "insufficient memory";
+      }
+   }
+
+   else
+      errmsg = "bad compression info";
+
+   if (errmsg != NULL)
+      png_chunk_benign_error(png_ptr, errmsg);
+}
+#endif
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+/* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
+static int
+png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
+{
+   png_alloc_size_t limit = PNG_SIZE_MAX;
+
+   if (png_ptr->unknown_chunk.data != NULL)
+   {
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+      png_ptr->unknown_chunk.data = NULL;
+   }
+
+#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_malloc_max > 0 &&
+       png_ptr->user_chunk_malloc_max < limit)
+      limit = png_ptr->user_chunk_malloc_max;
+
+#  elif PNG_USER_CHUNK_MALLOC_MAX > 0
+   if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+      limit = PNG_USER_CHUNK_MALLOC_MAX;
+#  endif
+
+   if (length <= limit)
+   {
+      PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
+      /* The following is safe because of the PNG_SIZE_MAX init above */
+      png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
+      /* 'mode' is a flag array, only the bottom four bits matter here */
+      png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
+
+      if (length == 0)
+         png_ptr->unknown_chunk.data = NULL;
+
+      else
+      {
+         /* Do a 'warn' here - it is handled below. */
+         png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
+             png_malloc_warn(png_ptr, length));
+      }
+   }
+
+   if (png_ptr->unknown_chunk.data == NULL && length > 0)
+   {
+      /* This is benign because we clean up correctly */
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
+      return 0;
+   }
+
+   else
+   {
+      if (length > 0)
+         png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
+      png_crc_finish(png_ptr, 0);
+      return 1;
+   }
+}
+#endif /* READ_UNKNOWN_CHUNKS */
+
+/* Handle an unknown, or known but disabled, chunk */
+void /* PRIVATE */
+png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
+    png_uint_32 length, int keep)
+{
+   int handled = 0; /* the chunk was handled */
+
+   png_debug(1, "in png_handle_unknown");
+
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
+    * the bug which meant that setting a non-default behavior for a specific
+    * chunk would be ignored (the default was always used unless a user
+    * callback was installed).
+    *
+    * 'keep' is the value from the png_chunk_unknown_handling, the setting for
+    * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
+    * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
+    * This is just an optimization to avoid multiple calls to the lookup
+    * function.
+    */
+#  ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#     ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+#     endif
+#  endif
+
+   /* One of the following methods will read the chunk or skip it (at least one
+    * of these is always defined because this is the only way to switch on
+    * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+    */
+#  ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   /* The user callback takes precedence over the chunk keep value, but the
+    * keep value is still required to validate a save of a critical chunk.
+    */
+   if (png_ptr->read_user_chunk_fn != NULL)
+   {
+      if (png_cache_unknown_chunk(png_ptr, length) != 0)
+      {
+         /* Callback to user unknown chunk handler */
+         int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
+             &png_ptr->unknown_chunk);
+
+         /* ret is:
+          * negative: An error occurred; png_chunk_error will be called.
+          *     zero: The chunk was not handled, the chunk will be discarded
+          *           unless png_set_keep_unknown_chunks has been used to set
+          *           a 'keep' behavior for this particular chunk, in which
+          *           case that will be used.  A critical chunk will cause an
+          *           error at this point unless it is to be saved.
+          * positive: The chunk was handled, libpng will ignore/discard it.
+          */
+         if (ret < 0)
+            png_chunk_error(png_ptr, "error in user chunk");
+
+         else if (ret == 0)
+         {
+            /* If the keep value is 'default' or 'never' override it, but
+             * still error out on critical chunks unless the keep value is
+             * 'always'  While this is weird it is the behavior in 1.4.12.
+             * A possible improvement would be to obey the value set for the
+             * chunk, but this would be an API change that would probably
+             * damage some applications.
+             *
+             * The png_app_warning below catches the case that matters, where
+             * the application has not set specific save or ignore for this
+             * chunk or global save or ignore.
+             */
+            if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
+            {
+#              ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+               if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
+               {
+                  png_chunk_warning(png_ptr, "Saving unknown chunk:");
+                  png_app_warning(png_ptr,
+                      "forcing save of an unhandled chunk;"
+                      " please call png_set_keep_unknown_chunks");
+                      /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
+               }
+#              endif
+               keep = PNG_HANDLE_CHUNK_IF_SAFE;
+            }
+         }
+
+         else /* chunk was handled */
+         {
+            handled = 1;
+            /* Critical chunks can be safely discarded at this point. */
+            keep = PNG_HANDLE_CHUNK_NEVER;
+         }
+      }
+
+      else
+         keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
+   }
+
+   else
+   /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
+#  endif /* READ_USER_CHUNKS */
+
+#  ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      /* keep is currently just the per-chunk setting, if there was no
+       * setting change it to the global default now (not that this may
+       * still be AS_DEFAULT) then obtain the cache of the chunk if required,
+       * if not simply skip the chunk.
+       */
+      if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+         keep = png_ptr->unknown_default;
+
+      if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+         (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+          PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+      {
+         if (png_cache_unknown_chunk(png_ptr, length) == 0)
+            keep = PNG_HANDLE_CHUNK_NEVER;
+      }
+
+      else
+         png_crc_finish(png_ptr, length);
+   }
+#  else
+#     ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+#        error no method to support READ_UNKNOWN_CHUNKS
+#     endif
+
+   {
+      /* If here there is no read callback pointer set and no support is
+       * compiled in to just save the unknown chunks, so simply skip this
+       * chunk.  If 'keep' is something other than AS_DEFAULT or NEVER then
+       * the app has erroneously asked for unknown chunk saving when there
+       * is no support.
+       */
+      if (keep > PNG_HANDLE_CHUNK_NEVER)
+         png_app_error(png_ptr, "no unknown chunk support available");
+
+      png_crc_finish(png_ptr, length);
+   }
+#  endif
+
+#  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+   /* Now store the chunk in the chunk list if appropriate, and if the limits
+    * permit it.
+    */
+   if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
+      (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
+       PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
+   {
+#     ifdef PNG_USER_LIMITS_SUPPORTED
+      switch (png_ptr->user_chunk_cache_max)
+      {
+         case 2:
+            png_ptr->user_chunk_cache_max = 1;
+            png_chunk_benign_error(png_ptr, "no space in chunk cache");
+            /* FALLTHROUGH */
+         case 1:
+            /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
+             * chunk being skipped, now there will be a hard error below.
+             */
+            break;
+
+         default: /* not at limit */
+            --(png_ptr->user_chunk_cache_max);
+            /* FALLTHROUGH */
+         case 0: /* no limit */
+#  endif /* USER_LIMITS */
+            /* Here when the limit isn't reached or when limits are compiled
+             * out; store the chunk.
+             */
+            png_set_unknown_chunks(png_ptr, info_ptr,
+                &png_ptr->unknown_chunk, 1);
+            handled = 1;
+#  ifdef PNG_USER_LIMITS_SUPPORTED
+            break;
+      }
+#  endif
+   }
+#  else /* no store support: the chunk must be handled by the user callback */
+   PNG_UNUSED(info_ptr)
+#  endif
+
+   /* Regardless of the error handling below the cached data (if any) can be
+    * freed now.  Notice that the data is not freed if there is a png_error, but
+    * it will be freed by destroy_read_struct.
+    */
+   if (png_ptr->unknown_chunk.data != NULL)
+      png_free(png_ptr, png_ptr->unknown_chunk.data);
+   png_ptr->unknown_chunk.data = NULL;
+
+#else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+   /* There is no support to read an unknown chunk, so just skip it. */
+   png_crc_finish(png_ptr, length);
+   PNG_UNUSED(info_ptr)
+   PNG_UNUSED(keep)
+#endif /* !READ_UNKNOWN_CHUNKS */
+
+   /* Check for unhandled critical chunks */
+   if (handled == 0 && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
+      png_chunk_error(png_ptr, "unhandled critical chunk");
+}
+
+/* This function is called to verify that a chunk name is valid.
+ * This function can't have the "critical chunk check" incorporated
+ * into it, since in the future we will need to be able to call user
+ * functions to handle unknown critical chunks after we check that
+ * the chunk name itself is valid.
+ */
+
+/* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
+ *
+ * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
+ */
+
+void /* PRIVATE */
+png_check_chunk_name(png_const_structrp png_ptr, const png_uint_32 chunk_name)
+{
+   int i;
+   png_uint_32 cn=chunk_name;
+
+   png_debug(1, "in png_check_chunk_name");
+
+   for (i=1; i<=4; ++i)
+   {
+      int c = cn & 0xff;
+
+      if (c < 65 || c > 122 || (c > 90 && c < 97))
+         png_chunk_error(png_ptr, "invalid chunk type");
+
+      cn >>= 8;
+   }
+}
+
+void /* PRIVATE */
+png_check_chunk_length(png_const_structrp png_ptr, const png_uint_32 length)
+{
+   png_alloc_size_t limit = PNG_UINT_31_MAX;
+
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
+   if (png_ptr->user_chunk_malloc_max > 0 &&
+       png_ptr->user_chunk_malloc_max < limit)
+      limit = png_ptr->user_chunk_malloc_max;
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+   if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+      limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+   if (png_ptr->chunk_name == png_IDAT)
+   {
+      png_alloc_size_t idat_limit = PNG_UINT_31_MAX;
+      size_t row_factor =
+         (png_ptr->width * png_ptr->channels * (png_ptr->bit_depth > 8? 2: 1)
+          + 1 + (png_ptr->interlaced? 6: 0));
+      if (png_ptr->height > PNG_UINT_32_MAX/row_factor)
+         idat_limit=PNG_UINT_31_MAX;
+      else
+         idat_limit = png_ptr->height * row_factor;
+      row_factor = row_factor > 32566? 32566 : row_factor;
+      idat_limit += 6 + 5*(idat_limit/row_factor+1); /* zlib+deflate overhead */
+      idat_limit=idat_limit < PNG_UINT_31_MAX? idat_limit : PNG_UINT_31_MAX;
+      limit = limit < idat_limit? idat_limit : limit;
+   }
+
+   if (length > limit)
+   {
+      png_debug2(0," length = %lu, limit = %lu",
+         (unsigned long)length,(unsigned long)limit);
+      png_chunk_error(png_ptr, "chunk data is too large");
+   }
+}
+
+/* Combines the row recently read in with the existing pixels in the row.  This
+ * routine takes care of alpha and transparency if requested.  This routine also
+ * handles the two methods of progressive display of interlaced images,
+ * depending on the 'display' value; if 'display' is true then the whole row
+ * (dp) is filled from the start by replicating the available pixels.  If
+ * 'display' is false only those pixels present in the pass are filled in.
+ */
+void /* PRIVATE */
+png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
+{
+   unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
+   png_const_bytep sp = png_ptr->row_buf + 1;
+   png_alloc_size_t row_width = png_ptr->width;
+   unsigned int pass = png_ptr->pass;
+   png_bytep end_ptr = 0;
+   png_byte end_byte = 0;
+   unsigned int end_mask;
+
+   png_debug(1, "in png_combine_row");
+
+   /* Added in 1.5.6: it should not be possible to enter this routine until at
+    * least one row has been read from the PNG data and transformed.
+    */
+   if (pixel_depth == 0)
+      png_error(png_ptr, "internal row logic error");
+
+   /* Added in 1.5.4: the pixel depth should match the information returned by
+    * any call to png_read_update_info at this point.  Do not continue if we got
+    * this wrong.
+    */
+   if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+          PNG_ROWBYTES(pixel_depth, row_width))
+      png_error(png_ptr, "internal row size calculation error");
+
+   /* Don't expect this to ever happen: */
+   if (row_width == 0)
+      png_error(png_ptr, "internal row width error");
+
+   /* Preserve the last byte in cases where only part of it will be overwritten,
+    * the multiply below may overflow, we don't care because ANSI-C guarantees
+    * we get the low bits.
+    */
+   end_mask = (pixel_depth * row_width) & 7;
+   if (end_mask != 0)
+   {
+      /* end_ptr == NULL is a flag to say do nothing */
+      end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
+      end_byte = *end_ptr;
+#     ifdef PNG_READ_PACKSWAP_SUPPORTED
+      if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+         /* little-endian byte */
+         end_mask = (unsigned int)(0xff << end_mask);
+
+      else /* big-endian byte */
+#     endif
+      end_mask = 0xff >> end_mask;
+      /* end_mask is now the bits to *keep* from the destination row */
+   }
+
+   /* For non-interlaced images this reduces to a memcpy(). A memcpy()
+    * will also happen if interlacing isn't supported or if the application
+    * does not call png_set_interlace_handling().  In the latter cases the
+    * caller just gets a sequence of the unexpanded rows from each interlace
+    * pass.
+    */
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0 &&
+       pass < 6 && (display == 0 ||
+       /* The following copies everything for 'display' on passes 0, 2 and 4. */
+       (display == 1 && (pass & 1) != 0)))
+   {
+      /* Narrow images may have no bits in a pass; the caller should handle
+       * this, but this test is cheap:
+       */
+      if (row_width <= PNG_PASS_START_COL(pass))
+         return;
+
+      if (pixel_depth < 8)
+      {
+         /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
+          * into 32 bits, then a single loop over the bytes using the four byte
+          * values in the 32-bit mask can be used.  For the 'display' option the
+          * expanded mask may also not require any masking within a byte.  To
+          * make this work the PACKSWAP option must be taken into account - it
+          * simply requires the pixels to be reversed in each byte.
+          *
+          * The 'regular' case requires a mask for each of the first 6 passes,
+          * the 'display' case does a copy for the even passes in the range
+          * 0..6.  This has already been handled in the test above.
+          *
+          * The masks are arranged as four bytes with the first byte to use in
+          * the lowest bits (little-endian) regardless of the order (PACKSWAP or
+          * not) of the pixels in each byte.
+          *
+          * NOTE: the whole of this logic depends on the caller of this function
+          * only calling it on rows appropriate to the pass.  This function only
+          * understands the 'x' logic; the 'y' logic is handled by the caller.
+          *
+          * The following defines allow generation of compile time constant bit
+          * masks for each pixel depth and each possibility of swapped or not
+          * swapped bytes.  Pass 'p' is in the range 0..6; 'x', a pixel index,
+          * is in the range 0..7; and the result is 1 if the pixel is to be
+          * copied in the pass, 0 if not.  'S' is for the sparkle method, 'B'
+          * for the block method.
+          *
+          * With some compilers a compile time expression of the general form:
+          *
+          *    (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
+          *
+          * Produces warnings with values of 'shift' in the range 33 to 63
+          * because the right hand side of the ?: expression is evaluated by
+          * the compiler even though it isn't used.  Microsoft Visual C (various
+          * versions) and the Intel C compiler are known to do this.  To avoid
+          * this the following macros are used in 1.5.6.  This is a temporary
+          * solution to avoid destabilizing the code during the release process.
+          */
+#        if PNG_USE_COMPILE_TIME_MASKS
+#           define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
+#           define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
+#        else
+#           define PNG_LSR(x,s) ((x)>>(s))
+#           define PNG_LSL(x,s) ((x)<<(s))
+#        endif
+#        define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
+           PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
+#        define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
+           PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
+
+         /* Return a mask for pass 'p' pixel 'x' at depth 'd'.  The mask is
+          * little endian - the first pixel is at bit 0 - however the extra
+          * parameter 's' can be set to cause the mask position to be swapped
+          * within each byte, to match the PNG format.  This is done by XOR of
+          * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
+          */
+#        define PIXEL_MASK(p,x,d,s) \
+            (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
+
+         /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
+          */
+#        define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+#        define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
+
+         /* Combine 8 of these to get the full mask.  For the 1-bpp and 2-bpp
+          * cases the result needs replicating, for the 4-bpp case the above
+          * generates a full 32 bits.
+          */
+#        define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
+
+#        define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
+            S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
+            S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
+
+#        define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
+            B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
+            B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
+
+#if PNG_USE_COMPILE_TIME_MASKS
+         /* Utility macros to construct all the masks for a depth/swap
+          * combination.  The 's' parameter says whether the format is PNG
+          * (big endian bytes) or not.  Only the three odd-numbered passes are
+          * required for the display/block algorithm.
+          */
+#        define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
+            S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
+
+#        define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) }
+
+#        define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
+
+         /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
+          * then pass:
+          */
+         static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
+         {
+            /* Little-endian byte masks for PACKSWAP */
+            { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
+            /* Normal (big-endian byte) masks - PNG format */
+            { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
+         };
+
+         /* display_mask has only three entries for the odd passes, so index by
+          * pass>>1.
+          */
+         static PNG_CONST png_uint_32 display_mask[2][3][3] =
+         {
+            /* Little-endian byte masks for PACKSWAP */
+            { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
+            /* Normal (big-endian byte) masks - PNG format */
+            { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
+         };
+
+#        define MASK(pass,depth,display,png)\
+            ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
+               row_mask[png][DEPTH_INDEX(depth)][pass])
+
+#else /* !PNG_USE_COMPILE_TIME_MASKS */
+         /* This is the runtime alternative: it seems unlikely that this will
+          * ever be either smaller or faster than the compile time approach.
+          */
+#        define MASK(pass,depth,display,png)\
+            ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
+#endif /* !USE_COMPILE_TIME_MASKS */
+
+         /* Use the appropriate mask to copy the required bits.  In some cases
+          * the byte mask will be 0 or 0xff; optimize these cases.  row_width is
+          * the number of pixels, but the code copies bytes, so it is necessary
+          * to special case the end.
+          */
+         png_uint_32 pixels_per_byte = 8 / pixel_depth;
+         png_uint_32 mask;
+
+#        ifdef PNG_READ_PACKSWAP_SUPPORTED
+         if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+            mask = MASK(pass, pixel_depth, display, 0);
+
+         else
+#        endif
+         mask = MASK(pass, pixel_depth, display, 1);
+
+         for (;;)
+         {
+            png_uint_32 m;
+
+            /* It doesn't matter in the following if png_uint_32 has more than
+             * 32 bits because the high bits always match those in m<<24; it is,
+             * however, essential to use OR here, not +, because of this.
+             */
+            m = mask;
+            mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
+            m &= 0xff;
+
+            if (m != 0) /* something to copy */
+            {
+               if (m != 0xff)
+                  *dp = (png_byte)((*dp & ~m) | (*sp & m));
+               else
+                  *dp = *sp;
+            }
+
+            /* NOTE: this may overwrite the last byte with garbage if the image
+             * is not an exact number of bytes wide; libpng has always done
+             * this.
+             */
+            if (row_width <= pixels_per_byte)
+               break; /* May need to restore part of the last byte */
+
+            row_width -= pixels_per_byte;
+            ++dp;
+            ++sp;
+         }
+      }
+
+      else /* pixel_depth >= 8 */
+      {
+         unsigned int bytes_to_copy, bytes_to_jump;
+
+         /* Validate the depth - it must be a multiple of 8 */
+         if (pixel_depth & 7)
+            png_error(png_ptr, "invalid user transform pixel depth");
+
+         pixel_depth >>= 3; /* now in bytes */
+         row_width *= pixel_depth;
+
+         /* Regardless of pass number the Adam 7 interlace always results in a
+          * fixed number of pixels to copy then to skip.  There may be a
+          * different number of pixels to skip at the start though.
+          */
+         {
+            unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
+
+            row_width -= offset;
+            dp += offset;
+            sp += offset;
+         }
+
+         /* Work out the bytes to copy. */
+         if (display != 0)
+         {
+            /* When doing the 'block' algorithm the pixel in the pass gets
+             * replicated to adjacent pixels.  This is why the even (0,2,4,6)
+             * passes are skipped above - the entire expanded row is copied.
+             */
+            bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
+
+            /* But don't allow this number to exceed the actual row width. */
+            if (bytes_to_copy > row_width)
+               bytes_to_copy = (unsigned int)/*SAFE*/row_width;
+         }
+
+         else /* normal row; Adam7 only ever gives us one pixel to copy. */
+            bytes_to_copy = pixel_depth;
+
+         /* In Adam7 there is a constant offset between where the pixels go. */
+         bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
+
+         /* And simply copy these bytes.  Some optimization is possible here,
+          * depending on the value of 'bytes_to_copy'.  Special case the low
+          * byte counts, which we know to be frequent.
+          *
+          * Notice that these cases all 'return' rather than 'break' - this
+          * avoids an unnecessary test on whether to restore the last byte
+          * below.
+          */
+         switch (bytes_to_copy)
+         {
+            case 1:
+               for (;;)
+               {
+                  *dp = *sp;
+
+                  if (row_width <= bytes_to_jump)
+                     return;
+
+                  dp += bytes_to_jump;
+                  sp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+               }
+
+            case 2:
+               /* There is a possibility of a partial copy at the end here; this
+                * slows the code down somewhat.
+                */
+               do
+               {
+                  dp[0] = sp[0]; dp[1] = sp[1];
+
+                  if (row_width <= bytes_to_jump)
+                     return;
+
+                  sp += bytes_to_jump;
+                  dp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+               }
+               while (row_width > 1);
+
+               /* And there can only be one byte left at this point: */
+               *dp = *sp;
+               return;
+
+            case 3:
+               /* This can only be the RGB case, so each copy is exactly one
+                * pixel and it is not necessary to check for a partial copy.
+                */
+               for (;;)
+               {
+                  dp[0] = sp[0]; dp[1] = sp[1]; dp[2] = sp[2];
+
+                  if (row_width <= bytes_to_jump)
+                     return;
+
+                  sp += bytes_to_jump;
+                  dp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+               }
+
+            default:
+#if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
+               /* Check for double byte alignment and, if possible, use a
+                * 16-bit copy.  Don't attempt this for narrow images - ones that
+                * are less than an interlace panel wide.  Don't attempt it for
+                * wide bytes_to_copy either - use the memcpy there.
+                */
+               if (bytes_to_copy < 16 /*else use memcpy*/ &&
+                   png_isaligned(dp, png_uint_16) &&
+                   png_isaligned(sp, png_uint_16) &&
+                   bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
+                   bytes_to_jump % (sizeof (png_uint_16)) == 0)
+               {
+                  /* Everything is aligned for png_uint_16 copies, but try for
+                   * png_uint_32 first.
+                   */
+                  if (png_isaligned(dp, png_uint_32) &&
+                      png_isaligned(sp, png_uint_32) &&
+                      bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
+                      bytes_to_jump % (sizeof (png_uint_32)) == 0)
+                  {
+                     png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
+                     png_const_uint_32p sp32 = png_aligncastconst(
+                         png_const_uint_32p, sp);
+                     size_t skip = (bytes_to_jump-bytes_to_copy) /
+                         (sizeof (png_uint_32));
+
+                     do
+                     {
+                        size_t c = bytes_to_copy;
+                        do
+                        {
+                           *dp32++ = *sp32++;
+                           c -= (sizeof (png_uint_32));
+                        }
+                        while (c > 0);
+
+                        if (row_width <= bytes_to_jump)
+                           return;
+
+                        dp32 += skip;
+                        sp32 += skip;
+                        row_width -= bytes_to_jump;
+                     }
+                     while (bytes_to_copy <= row_width);
+
+                     /* Get to here when the row_width truncates the final copy.
+                      * There will be 1-3 bytes left to copy, so don't try the
+                      * 16-bit loop below.
+                      */
+                     dp = (png_bytep)dp32;
+                     sp = (png_const_bytep)sp32;
+                     do
+                        *dp++ = *sp++;
+                     while (--row_width > 0);
+                     return;
+                  }
+
+                  /* Else do it in 16-bit quantities, but only if the size is
+                   * not too large.
+                   */
+                  else
+                  {
+                     png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
+                     png_const_uint_16p sp16 = png_aligncastconst(
+                        png_const_uint_16p, sp);
+                     size_t skip = (bytes_to_jump-bytes_to_copy) /
+                        (sizeof (png_uint_16));
+
+                     do
+                     {
+                        size_t c = bytes_to_copy;
+                        do
+                        {
+                           *dp16++ = *sp16++;
+                           c -= (sizeof (png_uint_16));
+                        }
+                        while (c > 0);
+
+                        if (row_width <= bytes_to_jump)
+                           return;
+
+                        dp16 += skip;
+                        sp16 += skip;
+                        row_width -= bytes_to_jump;
+                     }
+                     while (bytes_to_copy <= row_width);
+
+                     /* End of row - 1 byte left, bytes_to_copy > row_width: */
+                     dp = (png_bytep)dp16;
+                     sp = (png_const_bytep)sp16;
+                     do
+                        *dp++ = *sp++;
+                     while (--row_width > 0);
+                     return;
+                  }
+               }
+#endif /* ALIGN_TYPE code */
+
+               /* The true default - use a memcpy: */
+               for (;;)
+               {
+                  memcpy(dp, sp, bytes_to_copy);
+
+                  if (row_width <= bytes_to_jump)
+                     return;
+
+                  sp += bytes_to_jump;
+                  dp += bytes_to_jump;
+                  row_width -= bytes_to_jump;
+                  if (bytes_to_copy > row_width)
+                     bytes_to_copy = (unsigned int)/*SAFE*/row_width;
+               }
+         }
+
+         /* NOT REACHED*/
+      } /* pixel_depth >= 8 */
+
+      /* Here if pixel_depth < 8 to check 'end_ptr' below. */
+   }
+   else
+#endif /* READ_INTERLACING */
+
+   /* If here then the switch above wasn't used so just memcpy the whole row
+    * from the temporary row buffer (notice that this overwrites the end of the
+    * destination row if it is a partial byte.)
+    */
+   memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
+
+   /* Restore the overwritten bits from the last byte if necessary. */
+   if (end_ptr != NULL)
+      *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
+}
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+void /* PRIVATE */
+png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+    png_uint_32 transformations /* Because these may affect the byte layout */)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Offset to next interlace block */
+   static PNG_CONST unsigned int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   png_debug(1, "in png_do_read_interlace");
+   if (row != NULL && row_info != NULL)
+   {
+      png_uint_32 final_width;
+
+      final_width = row_info->width * png_pass_inc[pass];
+
+      switch (row_info->pixel_depth)
+      {
+         case 1:
+         {
+            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
+            png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
+            unsigned int sshift, dshift;
+            unsigned int s_start, s_end;
+            int s_inc;
+            int jstop = (int)png_pass_inc[pass];
+            png_byte v;
+            png_uint_32 i;
+            int j;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if ((transformations & PNG_PACKSWAP) != 0)
+            {
+                sshift = ((row_info->width + 7) & 0x07);
+                dshift = ((final_width + 7) & 0x07);
+                s_start = 7;
+                s_end = 0;
+                s_inc = -1;
+            }
+
+            else
+#endif
+            {
+                sshift = 7 - ((row_info->width + 7) & 0x07);
+                dshift = 7 - ((final_width + 7) & 0x07);
+                s_start = 0;
+                s_end = 7;
+                s_inc = 1;
+            }
+
+            for (i = 0; i < row_info->width; i++)
+            {
+               v = (png_byte)((*sp >> sshift) & 0x01);
+               for (j = 0; j < jstop; j++)
+               {
+                  unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
+                  tmp |= (unsigned int)(v << dshift);
+                  *dp = (png_byte)(tmp & 0xff);
+
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+
+                  else
+                     dshift = (unsigned int)((int)dshift + s_inc);
+               }
+
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+
+               else
+                  sshift = (unsigned int)((int)sshift + s_inc);
+            }
+            break;
+         }
+
+         case 2:
+         {
+            png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
+            png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
+            unsigned int sshift, dshift;
+            unsigned int s_start, s_end;
+            int s_inc;
+            int jstop = (int)png_pass_inc[pass];
+            png_uint_32 i;
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if ((transformations & PNG_PACKSWAP) != 0)
+            {
+               sshift = (((row_info->width + 3) & 0x03) << 1);
+               dshift = (((final_width + 3) & 0x03) << 1);
+               s_start = 6;
+               s_end = 0;
+               s_inc = -2;
+            }
+
+            else
+#endif
+            {
+               sshift = ((3 - ((row_info->width + 3) & 0x03)) << 1);
+               dshift = ((3 - ((final_width + 3) & 0x03)) << 1);
+               s_start = 0;
+               s_end = 6;
+               s_inc = 2;
+            }
+
+            for (i = 0; i < row_info->width; i++)
+            {
+               png_byte v;
+               int j;
+
+               v = (png_byte)((*sp >> sshift) & 0x03);
+               for (j = 0; j < jstop; j++)
+               {
+                  unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
+                  tmp |= (unsigned int)(v << dshift);
+                  *dp = (png_byte)(tmp & 0xff);
+
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+
+                  else
+                     dshift = (unsigned int)((int)dshift + s_inc);
+               }
+
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+
+               else
+                  sshift = (unsigned int)((int)sshift + s_inc);
+            }
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
+            png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
+            unsigned int sshift, dshift;
+            unsigned int s_start, s_end;
+            int s_inc;
+            png_uint_32 i;
+            int jstop = (int)png_pass_inc[pass];
+
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
+            if ((transformations & PNG_PACKSWAP) != 0)
+            {
+               sshift = (((row_info->width + 1) & 0x01) << 2);
+               dshift = (((final_width + 1) & 0x01) << 2);
+               s_start = 4;
+               s_end = 0;
+               s_inc = -4;
+            }
+
+            else
+#endif
+            {
+               sshift = ((1 - ((row_info->width + 1) & 0x01)) << 2);
+               dshift = ((1 - ((final_width + 1) & 0x01)) << 2);
+               s_start = 0;
+               s_end = 4;
+               s_inc = 4;
+            }
+
+            for (i = 0; i < row_info->width; i++)
+            {
+               png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
+               int j;
+
+               for (j = 0; j < jstop; j++)
+               {
+                  unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
+                  tmp |= (unsigned int)(v << dshift);
+                  *dp = (png_byte)(tmp & 0xff);
+
+                  if (dshift == s_end)
+                  {
+                     dshift = s_start;
+                     dp--;
+                  }
+
+                  else
+                     dshift = (unsigned int)((int)dshift + s_inc);
+               }
+
+               if (sshift == s_end)
+               {
+                  sshift = s_start;
+                  sp--;
+               }
+
+               else
+                  sshift = (unsigned int)((int)sshift + s_inc);
+            }
+            break;
+         }
+
+         default:
+         {
+            png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
+
+            png_bytep sp = row + (png_size_t)(row_info->width - 1)
+                * pixel_bytes;
+
+            png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
+
+            int jstop = (int)png_pass_inc[pass];
+            png_uint_32 i;
+
+            for (i = 0; i < row_info->width; i++)
+            {
+               png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
+               int j;
+
+               memcpy(v, sp, pixel_bytes);
+
+               for (j = 0; j < jstop; j++)
+               {
+                  memcpy(dp, v, pixel_bytes);
+                  dp -= pixel_bytes;
+               }
+
+               sp -= pixel_bytes;
+            }
+            break;
+         }
+      }
+
+      row_info->width = final_width;
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
+   }
+#ifndef PNG_READ_PACKSWAP_SUPPORTED
+   PNG_UNUSED(transformations)  /* Silence compiler warning */
+#endif
+}
+#endif /* READ_INTERLACING */
+
+static void
+png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
+    png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_size_t istop = row_info->rowbytes;
+   unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+   png_bytep rp = row + bpp;
+
+   PNG_UNUSED(prev_row)
+
+   for (i = bpp; i < istop; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
+      rp++;
+   }
+}
+
+static void
+png_read_filter_row_up(png_row_infop row_info, png_bytep row,
+    png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_size_t istop = row_info->rowbytes;
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+
+   for (i = 0; i < istop; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
+      rp++;
+   }
+}
+
+static void
+png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
+    png_const_bytep prev_row)
+{
+   png_size_t i;
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+   png_size_t istop = row_info->rowbytes - bpp;
+
+   for (i = 0; i < bpp; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) +
+         ((int)(*pp++) / 2 )) & 0xff);
+
+      rp++;
+   }
+
+   for (i = 0; i < istop; i++)
+   {
+      *rp = (png_byte)(((int)(*rp) +
+         (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
+
+      rp++;
+   }
+}
+
+static void
+png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
+    png_const_bytep prev_row)
+{
+   png_bytep rp_end = row + row_info->rowbytes;
+   int a, c;
+
+   /* First pixel/byte */
+   c = *prev_row++;
+   a = *row + c;
+   *row++ = (png_byte)a;
+
+   /* Remainder */
+   while (row < rp_end)
+   {
+      int b, pa, pb, pc, p;
+
+      a &= 0xff; /* From previous iteration or start */
+      b = *prev_row++;
+
+      p = b - c;
+      pc = a - c;
+
+#ifdef PNG_USE_ABS
+      pa = abs(p);
+      pb = abs(pc);
+      pc = abs(p + pc);
+#else
+      pa = p < 0 ? -p : p;
+      pb = pc < 0 ? -pc : pc;
+      pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+      /* Find the best predictor, the least of pa, pb, pc favoring the earlier
+       * ones in the case of a tie.
+       */
+      if (pb < pa)
+      {
+         pa = pb; a = b;
+      }
+      if (pc < pa) a = c;
+
+      /* Calculate the current pixel in a, and move the previous row pixel to c
+       * for the next time round the loop
+       */
+      c = b;
+      a += *row;
+      *row++ = (png_byte)a;
+   }
+}
+
+static void
+png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
+    png_const_bytep prev_row)
+{
+   unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
+   png_bytep rp_end = row + bpp;
+
+   /* Process the first pixel in the row completely (this is the same as 'up'
+    * because there is only one candidate predictor for the first row).
+    */
+   while (row < rp_end)
+   {
+      int a = *row + *prev_row++;
+      *row++ = (png_byte)a;
+   }
+
+   /* Remainder */
+   rp_end = rp_end + (row_info->rowbytes - bpp);
+
+   while (row < rp_end)
+   {
+      int a, b, c, pa, pb, pc, p;
+
+      c = *(prev_row - bpp);
+      a = *(row - bpp);
+      b = *prev_row++;
+
+      p = b - c;
+      pc = a - c;
+
+#ifdef PNG_USE_ABS
+      pa = abs(p);
+      pb = abs(pc);
+      pc = abs(p + pc);
+#else
+      pa = p < 0 ? -p : p;
+      pb = pc < 0 ? -pc : pc;
+      pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+      if (pb < pa)
+      {
+         pa = pb; a = b;
+      }
+      if (pc < pa) a = c;
+
+      a += *row;
+      *row++ = (png_byte)a;
+   }
+}
+
+static void
+png_init_filter_functions(png_structrp pp)
+   /* This function is called once for every PNG image (except for PNG images
+    * that only use PNG_FILTER_VALUE_NONE for all rows) to set the
+    * implementations required to reverse the filtering of PNG rows.  Reversing
+    * the filter is the first transformation performed on the row data.  It is
+    * performed in place, therefore an implementation can be selected based on
+    * the image pixel format.  If the implementation depends on image width then
+    * take care to ensure that it works correctly if the image is interlaced -
+    * interlacing causes the actual row width to vary.
+    */
+{
+   unsigned int bpp = (pp->pixel_depth + 7) >> 3;
+
+   pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
+   pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
+   if (bpp == 1)
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth_1byte_pixel;
+   else
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth_multibyte_pixel;
+
+#ifdef PNG_FILTER_OPTIMIZATIONS
+   /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
+    * call to install hardware optimizations for the above functions; simply
+    * replace whatever elements of the pp->read_filter[] array with a hardware
+    * specific (or, for that matter, generic) optimization.
+    *
+    * To see an example of this examine what configure.ac does when
+    * --enable-arm-neon is specified on the command line.
+    */
+   PNG_FILTER_OPTIMIZATIONS(pp, bpp);
+#endif
+}
+
+void /* PRIVATE */
+png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
+    png_const_bytep prev_row, int filter)
+{
+   /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
+    * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
+    * implementations.  See png_init_filter_functions above.
+    */
+   if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+   {
+      if (pp->read_filter[0] == NULL)
+         png_init_filter_functions(pp);
+
+      pp->read_filter[filter-1](row_info, row, prev_row);
+   }
+}
+
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+void /* PRIVATE */
+png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
+    png_alloc_size_t avail_out)
+{
+   /* Loop reading IDATs and decompressing the result into output[avail_out] */
+   png_ptr->zstream.next_out = output;
+   png_ptr->zstream.avail_out = 0; /* safety: set below */
+
+   if (output == NULL)
+      avail_out = 0;
+
+   do
+   {
+      int ret;
+      png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+      if (png_ptr->zstream.avail_in == 0)
+      {
+         uInt avail_in;
+         png_bytep buffer;
+
+         while (png_ptr->idat_size == 0)
+         {
+            png_crc_finish(png_ptr, 0);
+
+            png_ptr->idat_size = png_read_chunk_header(png_ptr);
+            /* This is an error even in the 'check' case because the code just
+             * consumed a non-IDAT header.
+             */
+            if (png_ptr->chunk_name != png_IDAT)
+               png_error(png_ptr, "Not enough image data");
+         }
+
+         avail_in = png_ptr->IDAT_read_size;
+
+         if (avail_in > png_ptr->idat_size)
+            avail_in = (uInt)png_ptr->idat_size;
+
+         /* A PNG with a gradually increasing IDAT size will defeat this attempt
+          * to minimize memory usage by causing lots of re-allocs, but
+          * realistically doing IDAT_read_size re-allocs is not likely to be a
+          * big problem.
+          */
+         buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/);
+
+         png_crc_read(png_ptr, buffer, avail_in);
+         png_ptr->idat_size -= avail_in;
+
+         png_ptr->zstream.next_in = buffer;
+         png_ptr->zstream.avail_in = avail_in;
+      }
+
+      /* And set up the output side. */
+      if (output != NULL) /* standard read */
+      {
+         uInt out = ZLIB_IO_MAX;
+
+         if (out > avail_out)
+            out = (uInt)avail_out;
+
+         avail_out -= out;
+         png_ptr->zstream.avail_out = out;
+      }
+
+      else /* after last row, checking for end */
+      {
+         png_ptr->zstream.next_out = tmpbuf;
+         png_ptr->zstream.avail_out = (sizeof tmpbuf);
+      }
+
+      /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
+       * process.  If the LZ stream is truncated the sequential reader will
+       * terminally damage the stream, above, by reading the chunk header of the
+       * following chunk (it then exits with png_error).
+       *
+       * TODO: deal more elegantly with truncated IDAT lists.
+       */
+      ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH);
+
+      /* Take the unconsumed output back. */
+      if (output != NULL)
+         avail_out += png_ptr->zstream.avail_out;
+
+      else /* avail_out counts the extra bytes */
+         avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
+
+      png_ptr->zstream.avail_out = 0;
+
+      if (ret == Z_STREAM_END)
+      {
+         /* Do this for safety; we won't read any more into this row. */
+         png_ptr->zstream.next_out = NULL;
+
+         png_ptr->mode |= PNG_AFTER_IDAT;
+         png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+
+         if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
+            png_chunk_benign_error(png_ptr, "Extra compressed data");
+         break;
+      }
+
+      if (ret != Z_OK)
+      {
+         png_zstream_error(png_ptr, ret);
+
+         if (output != NULL)
+            png_chunk_error(png_ptr, png_ptr->zstream.msg);
+
+         else /* checking */
+         {
+            png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
+            return;
+         }
+      }
+   } while (avail_out > 0);
+
+   if (avail_out > 0)
+   {
+      /* The stream ended before the image; this is the same as too few IDATs so
+       * should be handled the same way.
+       */
+      if (output != NULL)
+         png_error(png_ptr, "Not enough image data");
+
+      else /* the deflate stream contained extra data */
+         png_chunk_benign_error(png_ptr, "Too much image data");
+   }
+}
+
+void /* PRIVATE */
+png_read_finish_IDAT(png_structrp png_ptr)
+{
+   /* We don't need any more data and the stream should have ended, however the
+    * LZ end code may actually not have been processed.  In this case we must
+    * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
+    * may still remain to be consumed.
+    */
+   if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+   {
+      /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
+       * the compressed stream, but the stream may be damaged too, so even after
+       * this call we may need to terminate the zstream ownership.
+       */
+      png_read_IDAT_data(png_ptr, NULL, 0);
+      png_ptr->zstream.next_out = NULL; /* safety */
+
+      /* Now clear everything out for safety; the following may not have been
+       * done.
+       */
+      if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
+      {
+         png_ptr->mode |= PNG_AFTER_IDAT;
+         png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+      }
+   }
+
+   /* If the zstream has not been released do it now *and* terminate the reading
+    * of the final IDAT chunk.
+    */
+   if (png_ptr->zowner == png_IDAT)
+   {
+      /* Always do this; the pointers otherwise point into the read buffer. */
+      png_ptr->zstream.next_in = NULL;
+      png_ptr->zstream.avail_in = 0;
+
+      /* Now we no longer own the zstream. */
+      png_ptr->zowner = 0;
+
+      /* The slightly weird semantics of the sequential IDAT reading is that we
+       * are always in or at the end of an IDAT chunk, so we always need to do a
+       * crc_finish here.  If idat_size is non-zero we also need to read the
+       * spurious bytes at the end of the chunk now.
+       */
+      (void)png_crc_finish(png_ptr, png_ptr->idat_size);
+   }
+}
+
+void /* PRIVATE */
+png_read_finish_row(png_structrp png_ptr)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+   png_debug(1, "in png_read_finish_row");
+   png_ptr->row_number++;
+   if (png_ptr->row_number < png_ptr->num_rows)
+      return;
+
+   if (png_ptr->interlaced != 0)
+   {
+      png_ptr->row_number = 0;
+
+      /* TO DO: don't do this if prev_row isn't needed (requires
+       * read-ahead of the next row's filter byte.
+       */
+      memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+      do
+      {
+         png_ptr->pass++;
+
+         if (png_ptr->pass >= 7)
+            break;
+
+         png_ptr->iwidth = (png_ptr->width +
+            png_pass_inc[png_ptr->pass] - 1 -
+            png_pass_start[png_ptr->pass]) /
+            png_pass_inc[png_ptr->pass];
+
+         if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+         {
+            png_ptr->num_rows = (png_ptr->height +
+                png_pass_yinc[png_ptr->pass] - 1 -
+                png_pass_ystart[png_ptr->pass]) /
+                png_pass_yinc[png_ptr->pass];
+         }
+
+         else  /* if (png_ptr->transformations & PNG_INTERLACE) */
+            break; /* libpng deinterlacing sees every row */
+
+      } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
+
+      if (png_ptr->pass < 7)
+         return;
+   }
+
+   /* Here after at the end of the last row of the last pass. */
+   png_read_finish_IDAT(png_ptr);
+}
+#endif /* SEQUENTIAL_READ */
+
+void /* PRIVATE */
+png_read_start_row(png_structrp png_ptr)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+
+   unsigned int max_pixel_depth;
+   png_size_t row_bytes;
+
+   png_debug(1, "in png_read_start_row");
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+   png_init_read_transformations(png_ptr);
+#endif
+   if (png_ptr->interlaced != 0)
+   {
+      if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+         png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+             png_pass_ystart[0]) / png_pass_yinc[0];
+
+      else
+         png_ptr->num_rows = png_ptr->height;
+
+      png_ptr->iwidth = (png_ptr->width +
+          png_pass_inc[png_ptr->pass] - 1 -
+          png_pass_start[png_ptr->pass]) /
+          png_pass_inc[png_ptr->pass];
+   }
+
+   else
+   {
+      png_ptr->num_rows = png_ptr->height;
+      png_ptr->iwidth = png_ptr->width;
+   }
+
+   max_pixel_depth = (unsigned int)png_ptr->pixel_depth;
+
+   /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of
+    * calculations to calculate the final pixel depth, then
+    * png_do_read_transforms actually does the transforms.  This means that the
+    * code which effectively calculates this value is actually repeated in three
+    * separate places.  They must all match.  Innocent changes to the order of
+    * transformations can and will break libpng in a way that causes memory
+    * overwrites.
+    *
+    * TODO: fix this.
+    */
+#ifdef PNG_READ_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8)
+      max_pixel_depth = 8;
+#endif
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
+   if ((png_ptr->transformations & PNG_EXPAND) != 0)
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (png_ptr->num_trans != 0)
+            max_pixel_depth = 32;
+
+         else
+            max_pixel_depth = 24;
+      }
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (max_pixel_depth < 8)
+            max_pixel_depth = 8;
+
+         if (png_ptr->num_trans != 0)
+            max_pixel_depth *= 2;
+      }
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+      {
+         if (png_ptr->num_trans != 0)
+         {
+            max_pixel_depth *= 4;
+            max_pixel_depth /= 3;
+         }
+      }
+   }
+#endif
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
+   {
+#  ifdef PNG_READ_EXPAND_SUPPORTED
+      /* In fact it is an error if it isn't supported, but checking is
+       * the safe way.
+       */
+      if ((png_ptr->transformations & PNG_EXPAND) != 0)
+      {
+         if (png_ptr->bit_depth < 16)
+            max_pixel_depth *= 2;
+      }
+      else
+#  endif
+      png_ptr->transformations &= ~PNG_EXPAND_16;
+   }
+#endif
+
+#ifdef PNG_READ_FILLER_SUPPORTED
+   if ((png_ptr->transformations & (PNG_FILLER)) != 0)
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
+      {
+         if (max_pixel_depth <= 8)
+            max_pixel_depth = 16;
+
+         else
+            max_pixel_depth = 32;
+      }
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+         png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         if (max_pixel_depth <= 32)
+            max_pixel_depth = 32;
+
+         else
+            max_pixel_depth = 64;
+      }
+   }
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
+   {
+      if (
+#ifdef PNG_READ_EXPAND_SUPPORTED
+          (png_ptr->num_trans != 0 &&
+          (png_ptr->transformations & PNG_EXPAND) != 0) ||
+#endif
+#ifdef PNG_READ_FILLER_SUPPORTED
+          (png_ptr->transformations & (PNG_FILLER)) != 0 ||
+#endif
+          png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (max_pixel_depth <= 16)
+            max_pixel_depth = 32;
+
+         else
+            max_pixel_depth = 64;
+      }
+
+      else
+      {
+         if (max_pixel_depth <= 8)
+         {
+            if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+               max_pixel_depth = 32;
+
+            else
+               max_pixel_depth = 24;
+         }
+
+         else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            max_pixel_depth = 64;
+
+         else
+            max_pixel_depth = 48;
+      }
+   }
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
+defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+   {
+      unsigned int user_pixel_depth = png_ptr->user_transform_depth *
+         png_ptr->user_transform_channels;
+
+      if (user_pixel_depth > max_pixel_depth)
+         max_pixel_depth = user_pixel_depth;
+   }
+#endif
+
+   /* This value is stored in png_struct and double checked in the row read
+    * code.
+    */
+   png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
+   png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
+
+   /* Align the width on the next larger 8 pixels.  Mainly used
+    * for interlacing
+    */
+   row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
+   /* Calculate the maximum bytes needed, adding a byte and a pixel
+    * for safety's sake
+    */
+   row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
+       1 + ((max_pixel_depth + 7) >> 3U);
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (row_bytes > (png_uint_32)65536L)
+      png_error(png_ptr, "This image requires a row greater than 64KB");
+#endif
+
+   if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
+   {
+      png_free(png_ptr, png_ptr->big_row_buf);
+      png_free(png_ptr, png_ptr->big_prev_row);
+
+      if (png_ptr->interlaced != 0)
+         png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
+             row_bytes + 48);
+
+      else
+         png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+      png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
+
+#ifdef PNG_ALIGNED_MEMORY_SUPPORTED
+      /* Use 16-byte aligned memory for row_buf with at least 16 bytes
+       * of padding before and after row_buf; treat prev_row similarly.
+       * NOTE: the alignment is to the start of the pixels, one beyond the start
+       * of the buffer, because of the filter byte.  Prior to libpng 1.5.6 this
+       * was incorrect; the filter byte was aligned, which had the exact
+       * opposite effect of that intended.
+       */
+      {
+         png_bytep temp = png_ptr->big_row_buf + 32;
+         int extra = (int)((temp - (png_bytep)0) & 0x0f);
+         png_ptr->row_buf = temp - extra - 1/*filter byte*/;
+
+         temp = png_ptr->big_prev_row + 32;
+         extra = (int)((temp - (png_bytep)0) & 0x0f);
+         png_ptr->prev_row = temp - extra - 1/*filter byte*/;
+      }
+
+#else
+      /* Use 31 bytes of padding before and 17 bytes after row_buf. */
+      png_ptr->row_buf = png_ptr->big_row_buf + 31;
+      png_ptr->prev_row = png_ptr->big_prev_row + 31;
+#endif
+      png_ptr->old_big_row_buf_size = row_bytes + 48;
+   }
+
+#ifdef PNG_MAX_MALLOC_64K
+   if (png_ptr->rowbytes > 65535)
+      png_error(png_ptr, "This image requires a row greater than 64KB");
+
+#endif
+   if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
+      png_error(png_ptr, "Row has too many bytes to allocate in memory");
+
+   memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+
+   png_debug1(3, "width = %u,", png_ptr->width);
+   png_debug1(3, "height = %u,", png_ptr->height);
+   png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
+   png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
+   png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
+   png_debug1(3, "irowbytes = %lu",
+       (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
+
+   /* The sequential reader needs a buffer for IDAT, but the progressive reader
+    * does not, so free the read buffer now regardless; the sequential reader
+    * reallocates it on demand.
+    */
+   if (png_ptr->read_buffer != NULL)
+   {
+      png_bytep buffer = png_ptr->read_buffer;
+
+      png_ptr->read_buffer_size = 0;
+      png_ptr->read_buffer = NULL;
+      png_free(png_ptr, buffer);
+   }
+
+   /* Finally claim the zstream for the inflate of the IDAT data, use the bits
+    * value from the stream (note that this will result in a fatal error if the
+    * IDAT stream has a bogus deflate header window_bits value, but this should
+    * not be happening any longer!)
+    */
+   if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
+      png_error(png_ptr, png_ptr->zstream.msg);
+
+   png_ptr->flags |= PNG_FLAG_ROW_INIT;
+}
+#endif /* READ */
diff --git a/xs/src/png/libpng/pngset.c b/xs/src/png/libpng/pngset.c
new file mode 100644
index 000000000..6f3a1ee11
--- /dev/null
+++ b/xs/src/png/libpng/pngset.c
@@ -0,0 +1,1802 @@
+
+/* pngset.c - storage of image information into info struct
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * The functions here are used during reads to store data from the file
+ * into the info struct, and during writes to store application data
+ * into the info struct for writing into the file.  This abstracts the
+ * info struct and allows us to change the structure in the future.
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#ifdef PNG_bKGD_SUPPORTED
+void PNGAPI
+png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_color_16p background)
+{
+   png_debug1(1, "in %s storage function", "bKGD");
+
+   if (png_ptr == NULL || info_ptr == NULL || background == NULL)
+      return;
+
+   info_ptr->background = *background;
+   info_ptr->valid |= PNG_INFO_bKGD;
+}
+#endif
+
+#ifdef PNG_cHRM_SUPPORTED
+void PNGFAPI
+png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+    png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+    png_fixed_point blue_x, png_fixed_point blue_y)
+{
+   png_xy xy;
+
+   png_debug1(1, "in %s storage function", "cHRM fixed");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   xy.redx = red_x;
+   xy.redy = red_y;
+   xy.greenx = green_x;
+   xy.greeny = green_y;
+   xy.bluex = blue_x;
+   xy.bluey = blue_y;
+   xy.whitex = white_x;
+   xy.whitey = white_y;
+
+   if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy,
+       2/* override with app values*/) != 0)
+      info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+
+   png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+void PNGFAPI
+png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_fixed_point int_red_X, png_fixed_point int_red_Y,
+    png_fixed_point int_red_Z, png_fixed_point int_green_X,
+    png_fixed_point int_green_Y, png_fixed_point int_green_Z,
+    png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
+    png_fixed_point int_blue_Z)
+{
+   png_XYZ XYZ;
+
+   png_debug1(1, "in %s storage function", "cHRM XYZ fixed");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   XYZ.red_X = int_red_X;
+   XYZ.red_Y = int_red_Y;
+   XYZ.red_Z = int_red_Z;
+   XYZ.green_X = int_green_X;
+   XYZ.green_Y = int_green_Y;
+   XYZ.green_Z = int_green_Z;
+   XYZ.blue_X = int_blue_X;
+   XYZ.blue_Y = int_blue_Y;
+   XYZ.blue_Z = int_blue_Z;
+
+   if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace,
+       &XYZ, 2) != 0)
+      info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
+
+   png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
+    double white_x, double white_y, double red_x, double red_y,
+    double green_x, double green_y, double blue_x, double blue_y)
+{
+   png_set_cHRM_fixed(png_ptr, info_ptr,
+       png_fixed(png_ptr, white_x, "cHRM White X"),
+       png_fixed(png_ptr, white_y, "cHRM White Y"),
+       png_fixed(png_ptr, red_x, "cHRM Red X"),
+       png_fixed(png_ptr, red_y, "cHRM Red Y"),
+       png_fixed(png_ptr, green_x, "cHRM Green X"),
+       png_fixed(png_ptr, green_y, "cHRM Green Y"),
+       png_fixed(png_ptr, blue_x, "cHRM Blue X"),
+       png_fixed(png_ptr, blue_y, "cHRM Blue Y"));
+}
+
+void PNGAPI
+png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
+    double red_Y, double red_Z, double green_X, double green_Y, double green_Z,
+    double blue_X, double blue_Y, double blue_Z)
+{
+   png_set_cHRM_XYZ_fixed(png_ptr, info_ptr,
+       png_fixed(png_ptr, red_X, "cHRM Red X"),
+       png_fixed(png_ptr, red_Y, "cHRM Red Y"),
+       png_fixed(png_ptr, red_Z, "cHRM Red Z"),
+       png_fixed(png_ptr, green_X, "cHRM Green X"),
+       png_fixed(png_ptr, green_Y, "cHRM Green Y"),
+       png_fixed(png_ptr, green_Z, "cHRM Green Z"),
+       png_fixed(png_ptr, blue_X, "cHRM Blue X"),
+       png_fixed(png_ptr, blue_Y, "cHRM Blue Y"),
+       png_fixed(png_ptr, blue_Z, "cHRM Blue Z"));
+}
+#  endif /* FLOATING_POINT */
+
+#endif /* cHRM */
+
+#ifdef PNG_eXIf_SUPPORTED
+void PNGAPI
+png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
+    const png_bytep eXIf_buf)
+{
+  png_warning(png_ptr, "png_set_eXIf does not work; use png_set_eXIf_1");
+  PNG_UNUSED(info_ptr)
+  PNG_UNUSED(eXIf_buf)
+}
+
+void PNGAPI
+png_set_eXIf_1(png_const_structrp png_ptr, png_inforp info_ptr,
+    const png_uint_32 num_exif, const png_bytep eXIf_buf)
+{
+   int i;
+
+   png_debug1(1, "in %s storage function", "eXIf");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if (info_ptr->exif)
+   {
+      png_free(png_ptr, info_ptr->exif);
+      info_ptr->exif = NULL;
+   }
+
+   info_ptr->num_exif = num_exif;
+
+   info_ptr->exif = png_voidcast(png_bytep, png_malloc_warn(png_ptr,
+       info_ptr->num_exif));
+
+   if (info_ptr->exif == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for eXIf chunk data");
+      return;
+   }
+
+   info_ptr->free_me |= PNG_FREE_EXIF;
+
+   for (i = 0; i < (int) info_ptr->num_exif; i++)
+      info_ptr->exif[i] = eXIf_buf[i];
+
+   info_ptr->valid |= PNG_INFO_eXIf;
+}
+#endif /* eXIf */
+
+#ifdef PNG_gAMA_SUPPORTED
+void PNGFAPI
+png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_fixed_point file_gamma)
+{
+   png_debug1(1, "in %s storage function", "gAMA");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   png_colorspace_set_gamma(png_ptr, &info_ptr->colorspace, file_gamma);
+   png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
+{
+   png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma,
+       "png_set_gAMA"));
+}
+#  endif
+#endif
+
+#ifdef PNG_hIST_SUPPORTED
+void PNGAPI
+png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_uint_16p hist)
+{
+   int i;
+
+   png_debug1(1, "in %s storage function", "hIST");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if (info_ptr->num_palette == 0 || info_ptr->num_palette
+       > PNG_MAX_PALETTE_LENGTH)
+   {
+      png_warning(png_ptr,
+          "Invalid palette size, hIST allocation skipped");
+
+      return;
+   }
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0);
+
+   /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in
+    * version 1.2.1
+    */
+   info_ptr->hist = png_voidcast(png_uint_16p, png_malloc_warn(png_ptr,
+       PNG_MAX_PALETTE_LENGTH * (sizeof (png_uint_16))));
+
+   if (info_ptr->hist == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for hIST chunk data");
+
+      return;
+   }
+
+   info_ptr->free_me |= PNG_FREE_HIST;
+
+   for (i = 0; i < info_ptr->num_palette; i++)
+      info_ptr->hist[i] = hist[i];
+
+   info_ptr->valid |= PNG_INFO_hIST;
+}
+#endif
+
+void PNGAPI
+png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_uint_32 width, png_uint_32 height, int bit_depth,
+    int color_type, int interlace_type, int compression_type,
+    int filter_type)
+{
+   png_debug1(1, "in %s storage function", "IHDR");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->width = width;
+   info_ptr->height = height;
+   info_ptr->bit_depth = (png_byte)bit_depth;
+   info_ptr->color_type = (png_byte)color_type;
+   info_ptr->compression_type = (png_byte)compression_type;
+   info_ptr->filter_type = (png_byte)filter_type;
+   info_ptr->interlace_type = (png_byte)interlace_type;
+
+   png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+       info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
+       info_ptr->compression_type, info_ptr->filter_type);
+
+   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      info_ptr->channels = 1;
+
+   else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      info_ptr->channels = 3;
+
+   else
+      info_ptr->channels = 1;
+
+   if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      info_ptr->channels++;
+
+   info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+
+   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+}
+
+#ifdef PNG_oFFs_SUPPORTED
+void PNGAPI
+png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_int_32 offset_x, png_int_32 offset_y, int unit_type)
+{
+   png_debug1(1, "in %s storage function", "oFFs");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->x_offset = offset_x;
+   info_ptr->y_offset = offset_y;
+   info_ptr->offset_unit_type = (png_byte)unit_type;
+   info_ptr->valid |= PNG_INFO_oFFs;
+}
+#endif
+
+#ifdef PNG_pCAL_SUPPORTED
+void PNGAPI
+png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
+    int nparams, png_const_charp units, png_charpp params)
+{
+   png_size_t length;
+   int i;
+
+   png_debug1(1, "in %s storage function", "pCAL");
+
+   if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
+       || (nparams > 0 && params == NULL))
+      return;
+
+   length = strlen(purpose) + 1;
+   png_debug1(3, "allocating purpose for info (%lu bytes)",
+       (unsigned long)length);
+
+   /* TODO: validate format of calibration name and unit name */
+
+   /* Check that the type matches the specification. */
+   if (type < 0 || type > 3)
+   {
+      png_chunk_report(png_ptr, "Invalid pCAL equation type",
+            PNG_CHUNK_WRITE_ERROR);
+      return;
+   }
+
+   if (nparams < 0 || nparams > 255)
+   {
+      png_chunk_report(png_ptr, "Invalid pCAL parameter count",
+            PNG_CHUNK_WRITE_ERROR);
+      return;
+   }
+
+   /* Validate params[nparams] */
+   for (i=0; i<nparams; ++i)
+   {
+      if (params[i] == NULL ||
+          !png_check_fp_string(params[i], strlen(params[i])))
+      {
+         png_chunk_report(png_ptr, "Invalid format for pCAL parameter",
+               PNG_CHUNK_WRITE_ERROR);
+         return;
+      }
+   }
+
+   info_ptr->pcal_purpose = png_voidcast(png_charp,
+       png_malloc_warn(png_ptr, length));
+
+   if (info_ptr->pcal_purpose == NULL)
+   {
+      png_chunk_report(png_ptr, "Insufficient memory for pCAL purpose",
+            PNG_CHUNK_WRITE_ERROR);
+      return;
+   }
+
+   memcpy(info_ptr->pcal_purpose, purpose, length);
+
+   png_debug(3, "storing X0, X1, type, and nparams in info");
+   info_ptr->pcal_X0 = X0;
+   info_ptr->pcal_X1 = X1;
+   info_ptr->pcal_type = (png_byte)type;
+   info_ptr->pcal_nparams = (png_byte)nparams;
+
+   length = strlen(units) + 1;
+   png_debug1(3, "allocating units for info (%lu bytes)",
+       (unsigned long)length);
+
+   info_ptr->pcal_units = png_voidcast(png_charp,
+       png_malloc_warn(png_ptr, length));
+
+   if (info_ptr->pcal_units == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for pCAL units");
+
+      return;
+   }
+
+   memcpy(info_ptr->pcal_units, units, length);
+
+   info_ptr->pcal_params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
+       (png_size_t)(((unsigned int)nparams + 1) * (sizeof (png_charp)))));
+
+   if (info_ptr->pcal_params == NULL)
+   {
+      png_warning(png_ptr, "Insufficient memory for pCAL params");
+
+      return;
+   }
+
+   memset(info_ptr->pcal_params, 0, ((unsigned int)nparams + 1) *
+       (sizeof (png_charp)));
+
+   for (i = 0; i < nparams; i++)
+   {
+      length = strlen(params[i]) + 1;
+      png_debug2(3, "allocating parameter %d for info (%lu bytes)", i,
+          (unsigned long)length);
+
+      info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
+
+      if (info_ptr->pcal_params[i] == NULL)
+      {
+         png_warning(png_ptr, "Insufficient memory for pCAL parameter");
+
+         return;
+      }
+
+      memcpy(info_ptr->pcal_params[i], params[i], length);
+   }
+
+   info_ptr->valid |= PNG_INFO_pCAL;
+   info_ptr->free_me |= PNG_FREE_PCAL;
+}
+#endif
+
+#ifdef PNG_sCAL_SUPPORTED
+void PNGAPI
+png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
+    int unit, png_const_charp swidth, png_const_charp sheight)
+{
+   png_size_t lengthw = 0, lengthh = 0;
+
+   png_debug1(1, "in %s storage function", "sCAL");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   /* Double check the unit (should never get here with an invalid
+    * unit unless this is an API call.)
+    */
+   if (unit != 1 && unit != 2)
+      png_error(png_ptr, "Invalid sCAL unit");
+
+   if (swidth == NULL || (lengthw = strlen(swidth)) == 0 ||
+       swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
+      png_error(png_ptr, "Invalid sCAL width");
+
+   if (sheight == NULL || (lengthh = strlen(sheight)) == 0 ||
+       sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
+      png_error(png_ptr, "Invalid sCAL height");
+
+   info_ptr->scal_unit = (png_byte)unit;
+
+   ++lengthw;
+
+   png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw);
+
+   info_ptr->scal_s_width = png_voidcast(png_charp,
+       png_malloc_warn(png_ptr, lengthw));
+
+   if (info_ptr->scal_s_width == NULL)
+   {
+      png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
+      return;
+   }
+
+   memcpy(info_ptr->scal_s_width, swidth, lengthw);
+
+   ++lengthh;
+
+   png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh);
+
+   info_ptr->scal_s_height = png_voidcast(png_charp,
+       png_malloc_warn(png_ptr, lengthh));
+
+   if (info_ptr->scal_s_height == NULL)
+   {
+      png_free (png_ptr, info_ptr->scal_s_width);
+      info_ptr->scal_s_width = NULL;
+
+      png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
+      return;
+   }
+
+   memcpy(info_ptr->scal_s_height, sheight, lengthh);
+
+   info_ptr->valid |= PNG_INFO_sCAL;
+   info_ptr->free_me |= PNG_FREE_SCAL;
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
+    double width, double height)
+{
+   png_debug1(1, "in %s storage function", "sCAL");
+
+   /* Check the arguments. */
+   if (width <= 0)
+      png_warning(png_ptr, "Invalid sCAL width ignored");
+
+   else if (height <= 0)
+      png_warning(png_ptr, "Invalid sCAL height ignored");
+
+   else
+   {
+      /* Convert 'width' and 'height' to ASCII. */
+      char swidth[PNG_sCAL_MAX_DIGITS+1];
+      char sheight[PNG_sCAL_MAX_DIGITS+1];
+
+      png_ascii_from_fp(png_ptr, swidth, (sizeof swidth), width,
+          PNG_sCAL_PRECISION);
+      png_ascii_from_fp(png_ptr, sheight, (sizeof sheight), height,
+          PNG_sCAL_PRECISION);
+
+      png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+   }
+}
+#  endif
+
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit,
+    png_fixed_point width, png_fixed_point height)
+{
+   png_debug1(1, "in %s storage function", "sCAL");
+
+   /* Check the arguments. */
+   if (width <= 0)
+      png_warning(png_ptr, "Invalid sCAL width ignored");
+
+   else if (height <= 0)
+      png_warning(png_ptr, "Invalid sCAL height ignored");
+
+   else
+   {
+      /* Convert 'width' and 'height' to ASCII. */
+      char swidth[PNG_sCAL_MAX_DIGITS+1];
+      char sheight[PNG_sCAL_MAX_DIGITS+1];
+
+      png_ascii_from_fixed(png_ptr, swidth, (sizeof swidth), width);
+      png_ascii_from_fixed(png_ptr, sheight, (sizeof sheight), height);
+
+      png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight);
+   }
+}
+#  endif
+#endif
+
+#ifdef PNG_pHYs_SUPPORTED
+void PNGAPI
+png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_uint_32 res_x, png_uint_32 res_y, int unit_type)
+{
+   png_debug1(1, "in %s storage function", "pHYs");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->x_pixels_per_unit = res_x;
+   info_ptr->y_pixels_per_unit = res_y;
+   info_ptr->phys_unit_type = (png_byte)unit_type;
+   info_ptr->valid |= PNG_INFO_pHYs;
+}
+#endif
+
+void PNGAPI
+png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
+    png_const_colorp palette, int num_palette)
+{
+
+   png_uint_32 max_palette_length;
+
+   png_debug1(1, "in %s storage function", "PLTE");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+      (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
+   if (num_palette < 0 || num_palette > (int) max_palette_length)
+   {
+      if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+         png_error(png_ptr, "Invalid palette length");
+
+      else
+      {
+         png_warning(png_ptr, "Invalid palette length");
+
+         return;
+      }
+   }
+
+   if ((num_palette > 0 && palette == NULL) ||
+      (num_palette == 0
+#        ifdef PNG_MNG_FEATURES_SUPPORTED
+            && (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0
+#        endif
+      ))
+   {
+      png_error(png_ptr, "Invalid palette");
+   }
+
+   /* It may not actually be necessary to set png_ptr->palette here;
+    * we do it for backward compatibility with the way the png_handle_tRNS
+    * function used to do the allocation.
+    *
+    * 1.6.0: the above statement appears to be incorrect; something has to set
+    * the palette inside png_struct on read.
+    */
+   png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);
+
+   /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
+    * of num_palette entries, in case of an invalid PNG file or incorrect
+    * call to png_set_PLTE() with too-large sample values.
+    */
+   png_ptr->palette = png_voidcast(png_colorp, png_calloc(png_ptr,
+       PNG_MAX_PALETTE_LENGTH * (sizeof (png_color))));
+
+   if (num_palette > 0)
+      memcpy(png_ptr->palette, palette, (unsigned int)num_palette *
+          (sizeof (png_color)));
+   info_ptr->palette = png_ptr->palette;
+   info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
+
+   info_ptr->free_me |= PNG_FREE_PLTE;
+
+   info_ptr->valid |= PNG_INFO_PLTE;
+}
+
+#ifdef PNG_sBIT_SUPPORTED
+void PNGAPI
+png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_color_8p sig_bit)
+{
+   png_debug1(1, "in %s storage function", "sBIT");
+
+   if (png_ptr == NULL || info_ptr == NULL || sig_bit == NULL)
+      return;
+
+   info_ptr->sig_bit = *sig_bit;
+   info_ptr->valid |= PNG_INFO_sBIT;
+}
+#endif
+
+#ifdef PNG_sRGB_SUPPORTED
+void PNGAPI
+png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
+{
+   png_debug1(1, "in %s storage function", "sRGB");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   (void)png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent);
+   png_colorspace_sync_info(png_ptr, info_ptr);
+}
+
+void PNGAPI
+png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
+    int srgb_intent)
+{
+   png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace,
+       srgb_intent) != 0)
+   {
+      /* This causes the gAMA and cHRM to be written too */
+      info_ptr->colorspace.flags |=
+         PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
+   }
+
+   png_colorspace_sync_info(png_ptr, info_ptr);
+}
+#endif /* sRGB */
+
+
+#ifdef PNG_iCCP_SUPPORTED
+void PNGAPI
+png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_charp name, int compression_type,
+    png_const_bytep profile, png_uint_32 proflen)
+{
+   png_charp new_iccp_name;
+   png_bytep new_iccp_profile;
+   png_size_t length;
+
+   png_debug1(1, "in %s storage function", "iCCP");
+
+   if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+      return;
+
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+      png_app_error(png_ptr, "Invalid iCCP compression method");
+
+   /* Set the colorspace first because this validates the profile; do not
+    * override previously set app cHRM or gAMA here (because likely as not the
+    * application knows better than libpng what the correct values are.)  Pass
+    * the info_ptr color_type field to png_colorspace_set_ICC because in the
+    * write case it has not yet been stored in png_ptr.
+    */
+   {
+      int result = png_colorspace_set_ICC(png_ptr, &info_ptr->colorspace, name,
+          proflen, profile, info_ptr->color_type);
+
+      png_colorspace_sync_info(png_ptr, info_ptr);
+
+      /* Don't do any of the copying if the profile was bad, or inconsistent. */
+      if (result == 0)
+         return;
+
+      /* But do write the gAMA and cHRM chunks from the profile. */
+      info_ptr->colorspace.flags |=
+         PNG_COLORSPACE_FROM_gAMA|PNG_COLORSPACE_FROM_cHRM;
+   }
+
+   length = strlen(name)+1;
+   new_iccp_name = png_voidcast(png_charp, png_malloc_warn(png_ptr, length));
+
+   if (new_iccp_name == NULL)
+   {
+      png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
+
+      return;
+   }
+
+   memcpy(new_iccp_name, name, length);
+   new_iccp_profile = png_voidcast(png_bytep,
+       png_malloc_warn(png_ptr, proflen));
+
+   if (new_iccp_profile == NULL)
+   {
+      png_free(png_ptr, new_iccp_name);
+      png_benign_error(png_ptr,
+          "Insufficient memory to process iCCP profile");
+
+      return;
+   }
+
+   memcpy(new_iccp_profile, profile, proflen);
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0);
+
+   info_ptr->iccp_proflen = proflen;
+   info_ptr->iccp_name = new_iccp_name;
+   info_ptr->iccp_profile = new_iccp_profile;
+   info_ptr->free_me |= PNG_FREE_ICCP;
+   info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+void PNGAPI
+png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_textp text_ptr, int num_text)
+{
+   int ret;
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
+
+   if (ret != 0)
+      png_error(png_ptr, "Insufficient memory to store text");
+}
+
+int /* PRIVATE */
+png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_textp text_ptr, int num_text)
+{
+   int i;
+
+   png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11U :
+      (unsigned long)png_ptr->chunk_name);
+
+   if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
+      return(0);
+
+   /* Make sure we have enough space in the "text" array in info_struct
+    * to hold all of the incoming text_ptr objects.  This compare can't overflow
+    * because max_text >= num_text (anyway, subtract of two positive integers
+    * can't overflow in any case.)
+    */
+   if (num_text > info_ptr->max_text - info_ptr->num_text)
+   {
+      int old_num_text = info_ptr->num_text;
+      int max_text;
+      png_textp new_text = NULL;
+
+      /* Calculate an appropriate max_text, checking for overflow. */
+      max_text = old_num_text;
+      if (num_text <= INT_MAX - max_text)
+      {
+         max_text += num_text;
+
+         /* Round up to a multiple of 8 */
+         if (max_text < INT_MAX-8)
+            max_text = (max_text + 8) & ~0x7;
+
+         else
+            max_text = INT_MAX;
+
+         /* Now allocate a new array and copy the old members in; this does all
+          * the overflow checks.
+          */
+         new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
+             info_ptr->text, old_num_text, max_text-old_num_text,
+             sizeof *new_text));
+      }
+
+      if (new_text == NULL)
+      {
+         png_chunk_report(png_ptr, "too many text chunks",
+             PNG_CHUNK_WRITE_ERROR);
+
+         return 1;
+      }
+
+      png_free(png_ptr, info_ptr->text);
+
+      info_ptr->text = new_text;
+      info_ptr->free_me |= PNG_FREE_TEXT;
+      info_ptr->max_text = max_text;
+      /* num_text is adjusted below as the entries are copied in */
+
+      png_debug1(3, "allocated %d entries for info_ptr->text", max_text);
+   }
+
+   for (i = 0; i < num_text; i++)
+   {
+      size_t text_length, key_len;
+      size_t lang_len, lang_key_len;
+      png_textp textp = &(info_ptr->text[info_ptr->num_text]);
+
+      if (text_ptr[i].key == NULL)
+          continue;
+
+      if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE ||
+          text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST)
+      {
+         png_chunk_report(png_ptr, "text compression mode is out of range",
+             PNG_CHUNK_WRITE_ERROR);
+         continue;
+      }
+
+      key_len = strlen(text_ptr[i].key);
+
+      if (text_ptr[i].compression <= 0)
+      {
+         lang_len = 0;
+         lang_key_len = 0;
+      }
+
+      else
+#  ifdef PNG_iTXt_SUPPORTED
+      {
+         /* Set iTXt data */
+
+         if (text_ptr[i].lang != NULL)
+            lang_len = strlen(text_ptr[i].lang);
+
+         else
+            lang_len = 0;
+
+         if (text_ptr[i].lang_key != NULL)
+            lang_key_len = strlen(text_ptr[i].lang_key);
+
+         else
+            lang_key_len = 0;
+      }
+#  else /* iTXt */
+      {
+         png_chunk_report(png_ptr, "iTXt chunk not supported",
+             PNG_CHUNK_WRITE_ERROR);
+         continue;
+      }
+#  endif
+
+      if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0')
+      {
+         text_length = 0;
+#  ifdef PNG_iTXt_SUPPORTED
+         if (text_ptr[i].compression > 0)
+            textp->compression = PNG_ITXT_COMPRESSION_NONE;
+
+         else
+#  endif
+            textp->compression = PNG_TEXT_COMPRESSION_NONE;
+      }
+
+      else
+      {
+         text_length = strlen(text_ptr[i].text);
+         textp->compression = text_ptr[i].compression;
+      }
+
+      textp->key = png_voidcast(png_charp,png_malloc_base(png_ptr,
+          key_len + text_length + lang_len + lang_key_len + 4));
+
+      if (textp->key == NULL)
+      {
+         png_chunk_report(png_ptr, "text chunk: out of memory",
+             PNG_CHUNK_WRITE_ERROR);
+
+         return 1;
+      }
+
+      png_debug2(2, "Allocated %lu bytes at %p in png_set_text",
+          (unsigned long)(png_uint_32)
+          (key_len + lang_len + lang_key_len + text_length + 4),
+          textp->key);
+
+      memcpy(textp->key, text_ptr[i].key, key_len);
+      *(textp->key + key_len) = '\0';
+
+      if (text_ptr[i].compression > 0)
+      {
+         textp->lang = textp->key + key_len + 1;
+         memcpy(textp->lang, text_ptr[i].lang, lang_len);
+         *(textp->lang + lang_len) = '\0';
+         textp->lang_key = textp->lang + lang_len + 1;
+         memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+         *(textp->lang_key + lang_key_len) = '\0';
+         textp->text = textp->lang_key + lang_key_len + 1;
+      }
+
+      else
+      {
+         textp->lang=NULL;
+         textp->lang_key=NULL;
+         textp->text = textp->key + key_len + 1;
+      }
+
+      if (text_length != 0)
+         memcpy(textp->text, text_ptr[i].text, text_length);
+
+      *(textp->text + text_length) = '\0';
+
+#  ifdef PNG_iTXt_SUPPORTED
+      if (textp->compression > 0)
+      {
+         textp->text_length = 0;
+         textp->itxt_length = text_length;
+      }
+
+      else
+#  endif
+      {
+         textp->text_length = text_length;
+         textp->itxt_length = 0;
+      }
+
+      info_ptr->num_text++;
+      png_debug1(3, "transferred text chunk %d", info_ptr->num_text);
+   }
+
+   return(0);
+}
+#endif
+
+#ifdef PNG_tIME_SUPPORTED
+void PNGAPI
+png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_timep mod_time)
+{
+   png_debug1(1, "in %s storage function", "tIME");
+
+   if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
+       (png_ptr->mode & PNG_WROTE_tIME) != 0)
+      return;
+
+   if (mod_time->month == 0   || mod_time->month > 12  ||
+       mod_time->day   == 0   || mod_time->day   > 31  ||
+       mod_time->hour  > 23   || mod_time->minute > 59 ||
+       mod_time->second > 60)
+   {
+      png_warning(png_ptr, "Ignoring invalid time value");
+
+      return;
+   }
+
+   info_ptr->mod_time = *mod_time;
+   info_ptr->valid |= PNG_INFO_tIME;
+}
+#endif
+
+#ifdef PNG_tRNS_SUPPORTED
+void PNGAPI
+png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
+    png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
+{
+   png_debug1(1, "in %s storage function", "tRNS");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+
+      return;
+
+   if (trans_alpha != NULL)
+   {
+       /* It may not actually be necessary to set png_ptr->trans_alpha here;
+        * we do it for backward compatibility with the way the png_handle_tRNS
+        * function used to do the allocation.
+        *
+        * 1.6.0: The above statement is incorrect; png_handle_tRNS effectively
+        * relies on png_set_tRNS storing the information in png_struct
+        * (otherwise it won't be there for the code in pngrtran.c).
+        */
+
+       png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+
+       if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
+       {
+         /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
+          info_ptr->trans_alpha = png_voidcast(png_bytep,
+              png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
+          memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
+       }
+       png_ptr->trans_alpha = info_ptr->trans_alpha;
+   }
+
+   if (trans_color != NULL)
+   {
+#ifdef PNG_WARNINGS_SUPPORTED
+      if (info_ptr->bit_depth < 16)
+      {
+         int sample_max = (1 << info_ptr->bit_depth) - 1;
+
+         if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+             trans_color->gray > sample_max) ||
+             (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+             (trans_color->red > sample_max ||
+             trans_color->green > sample_max ||
+             trans_color->blue > sample_max)))
+            png_warning(png_ptr,
+                "tRNS chunk has out-of-range samples for bit_depth");
+      }
+#endif
+
+      info_ptr->trans_color = *trans_color;
+
+      if (num_trans == 0)
+         num_trans = 1;
+   }
+
+   info_ptr->num_trans = (png_uint_16)num_trans;
+
+   if (num_trans != 0)
+   {
+      info_ptr->valid |= PNG_INFO_tRNS;
+      info_ptr->free_me |= PNG_FREE_TRNS;
+   }
+}
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+void PNGAPI
+png_set_sPLT(png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
+/*
+ *  entries        - array of png_sPLT_t structures
+ *                   to be added to the list of palettes
+ *                   in the info structure.
+ *
+ *  nentries       - number of palette structures to be
+ *                   added.
+ */
+{
+   png_sPLT_tp np;
+
+   if (png_ptr == NULL || info_ptr == NULL || nentries <= 0 || entries == NULL)
+      return;
+
+   /* Use the internal realloc function, which checks for all the possible
+    * overflows.  Notice that the parameters are (int) and (size_t)
+    */
+   np = png_voidcast(png_sPLT_tp,png_realloc_array(png_ptr,
+       info_ptr->splt_palettes, info_ptr->splt_palettes_num, nentries,
+       sizeof *np));
+
+   if (np == NULL)
+   {
+      /* Out of memory or too many chunks */
+      png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
+
+      return;
+   }
+
+   png_free(png_ptr, info_ptr->splt_palettes);
+   info_ptr->splt_palettes = np;
+   info_ptr->free_me |= PNG_FREE_SPLT;
+
+   np += info_ptr->splt_palettes_num;
+
+   do
+   {
+      png_size_t length;
+
+      /* Skip invalid input entries */
+      if (entries->name == NULL || entries->entries == NULL)
+      {
+         /* png_handle_sPLT doesn't do this, so this is an app error */
+         png_app_error(png_ptr, "png_set_sPLT: invalid sPLT");
+         /* Just skip the invalid entry */
+         continue;
+      }
+
+      np->depth = entries->depth;
+
+      /* In the event of out-of-memory just return - there's no point keeping
+       * on trying to add sPLT chunks.
+       */
+      length = strlen(entries->name) + 1;
+      np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
+
+      if (np->name == NULL)
+         break;
+
+      memcpy(np->name, entries->name, length);
+
+      /* IMPORTANT: we have memory now that won't get freed if something else
+       * goes wrong; this code must free it.  png_malloc_array produces no
+       * warnings; use a png_chunk_report (below) if there is an error.
+       */
+      np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
+          entries->nentries, sizeof (png_sPLT_entry)));
+
+      if (np->entries == NULL)
+      {
+         png_free(png_ptr, np->name);
+         np->name = NULL;
+         break;
+      }
+
+      np->nentries = entries->nentries;
+      /* This multiply can't overflow because png_malloc_array has already
+       * checked it when doing the allocation.
+       */
+      memcpy(np->entries, entries->entries,
+          (unsigned int)entries->nentries * sizeof (png_sPLT_entry));
+
+      /* Note that 'continue' skips the advance of the out pointer and out
+       * count, so an invalid entry is not added.
+       */
+      info_ptr->valid |= PNG_INFO_sPLT;
+      ++(info_ptr->splt_palettes_num);
+      ++np;
+      ++entries;
+   }
+   while (--nentries);
+
+   if (nentries > 0)
+      png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
+}
+#endif /* sPLT */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+static png_byte
+check_location(png_const_structrp png_ptr, int location)
+{
+   location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
+
+   /* New in 1.6.0; copy the location and check it.  This is an API
+    * change; previously the app had to use the
+    * png_set_unknown_chunk_location API below for each chunk.
+    */
+   if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+   {
+      /* Write struct, so unknown chunks come from the app */
+      png_app_warning(png_ptr,
+          "png_set_unknown_chunks now expects a valid location");
+      /* Use the old behavior */
+      location = (png_byte)(png_ptr->mode &
+          (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT));
+   }
+
+   /* This need not be an internal error - if the app calls
+    * png_set_unknown_chunks on a read pointer it must get the location right.
+    */
+   if (location == 0)
+      png_error(png_ptr, "invalid location in png_set_unknown_chunks");
+
+   /* Now reduce the location to the top-most set bit by removing each least
+    * significant bit in turn.
+    */
+   while (location != (location & -location))
+      location &= ~(location & -location);
+
+   /* The cast is safe because 'location' is a bit mask and only the low four
+    * bits are significant.
+    */
+   return (png_byte)location;
+}
+
+void PNGAPI
+png_set_unknown_chunks(png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
+{
+   png_unknown_chunkp np;
+
+   if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
+       unknowns == NULL)
+      return;
+
+   /* Check for the failure cases where support has been disabled at compile
+    * time.  This code is hardly ever compiled - it's here because
+    * STORE_UNKNOWN_CHUNKS is set by both read and write code (compiling in this
+    * code) but may be meaningless if the read or write handling of unknown
+    * chunks is not compiled in.
+    */
+#  if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
+      defined(PNG_READ_SUPPORTED)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+      {
+         png_app_error(png_ptr, "no unknown chunk support on read");
+
+         return;
+      }
+#  endif
+#  if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
+      defined(PNG_WRITE_SUPPORTED)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+      {
+         png_app_error(png_ptr, "no unknown chunk support on write");
+
+         return;
+      }
+#  endif
+
+   /* Prior to 1.6.0 this code used png_malloc_warn; however, this meant that
+    * unknown critical chunks could be lost with just a warning resulting in
+    * undefined behavior.  Now png_chunk_report is used to provide behavior
+    * appropriate to read or write.
+    */
+   np = png_voidcast(png_unknown_chunkp, png_realloc_array(png_ptr,
+       info_ptr->unknown_chunks, info_ptr->unknown_chunks_num, num_unknowns,
+       sizeof *np));
+
+   if (np == NULL)
+   {
+      png_chunk_report(png_ptr, "too many unknown chunks",
+          PNG_CHUNK_WRITE_ERROR);
+
+      return;
+   }
+
+   png_free(png_ptr, info_ptr->unknown_chunks);
+   info_ptr->unknown_chunks = np; /* safe because it is initialized */
+   info_ptr->free_me |= PNG_FREE_UNKN;
+
+   np += info_ptr->unknown_chunks_num;
+
+   /* Increment unknown_chunks_num each time round the loop to protect the
+    * just-allocated chunk data.
+    */
+   for (; num_unknowns > 0; --num_unknowns, ++unknowns)
+   {
+      memcpy(np->name, unknowns->name, (sizeof np->name));
+      np->name[(sizeof np->name)-1] = '\0';
+      np->location = check_location(png_ptr, unknowns->location);
+
+      if (unknowns->size == 0)
+      {
+         np->data = NULL;
+         np->size = 0;
+      }
+
+      else
+      {
+         np->data = png_voidcast(png_bytep,
+             png_malloc_base(png_ptr, unknowns->size));
+
+         if (np->data == NULL)
+         {
+            png_chunk_report(png_ptr, "unknown chunk: out of memory",
+                PNG_CHUNK_WRITE_ERROR);
+            /* But just skip storing the unknown chunk */
+            continue;
+         }
+
+         memcpy(np->data, unknowns->data, unknowns->size);
+         np->size = unknowns->size;
+      }
+
+      /* These increments are skipped on out-of-memory for the data - the
+       * unknown chunk entry gets overwritten if the png_chunk_report returns.
+       * This is correct in the read case (the chunk is just dropped.)
+       */
+      ++np;
+      ++(info_ptr->unknown_chunks_num);
+   }
+}
+
+void PNGAPI
+png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
+    int chunk, int location)
+{
+   /* This API is pretty pointless in 1.6.0 because the location can be set
+    * before the call to png_set_unknown_chunks.
+    *
+    * TODO: add a png_app_warning in 1.7
+    */
+   if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
+      chunk < info_ptr->unknown_chunks_num)
+   {
+      if ((location & (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT)) == 0)
+      {
+         png_app_error(png_ptr, "invalid unknown chunk location");
+         /* Fake out the pre 1.6.0 behavior: */
+         if (((unsigned int)location & PNG_HAVE_IDAT) != 0) /* undocumented! */
+            location = PNG_AFTER_IDAT;
+
+         else
+            location = PNG_HAVE_IHDR; /* also undocumented */
+      }
+
+      info_ptr->unknown_chunks[chunk].location =
+         check_location(png_ptr, location);
+   }
+}
+#endif /* STORE_UNKNOWN_CHUNKS */
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+png_uint_32 PNGAPI
+png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
+{
+   png_debug(1, "in png_permit_mng_features");
+
+   if (png_ptr == NULL)
+      return 0;
+
+   png_ptr->mng_features_permitted = mng_features & PNG_ALL_MNG_FEATURES;
+
+   return png_ptr->mng_features_permitted;
+}
+#endif
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+static unsigned int
+add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
+{
+   unsigned int i;
+
+   /* Utility function: update the 'keep' state of a chunk if it is already in
+    * the list, otherwise add it to the list.
+    */
+   for (i=0; i<count; ++i, list += 5)
+   {
+      if (memcmp(list, add, 4) == 0)
+      {
+         list[4] = (png_byte)keep;
+
+         return count;
+      }
+   }
+
+   if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
+   {
+      ++count;
+      memcpy(list, add, 4);
+      list[4] = (png_byte)keep;
+   }
+
+   return count;
+}
+
+void PNGAPI
+png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
+    png_const_bytep chunk_list, int num_chunks_in)
+{
+   png_bytep new_list;
+   unsigned int num_chunks, old_num_chunks;
+
+   if (png_ptr == NULL)
+      return;
+
+   if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
+   {
+      png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
+
+      return;
+   }
+
+   if (num_chunks_in <= 0)
+   {
+      png_ptr->unknown_default = keep;
+
+      /* '0' means just set the flags, so stop here */
+      if (num_chunks_in == 0)
+        return;
+   }
+
+   if (num_chunks_in < 0)
+   {
+      /* Ignore all unknown chunks and all chunks recognized by
+       * libpng except for IHDR, PLTE, tRNS, IDAT, and IEND
+       */
+      static PNG_CONST png_byte chunks_to_ignore[] = {
+         98,  75,  71,  68, '\0',  /* bKGD */
+         99,  72,  82,  77, '\0',  /* cHRM */
+        101,  88,  73, 102, '\0',  /* eXIf */
+        103,  65,  77,  65, '\0',  /* gAMA */
+        104,  73,  83,  84, '\0',  /* hIST */
+        105,  67,  67,  80, '\0',  /* iCCP */
+        105,  84,  88, 116, '\0',  /* iTXt */
+        111,  70,  70, 115, '\0',  /* oFFs */
+        112,  67,  65,  76, '\0',  /* pCAL */
+        112,  72,  89, 115, '\0',  /* pHYs */
+        115,  66,  73,  84, '\0',  /* sBIT */
+        115,  67,  65,  76, '\0',  /* sCAL */
+        115,  80,  76,  84, '\0',  /* sPLT */
+        115,  84,  69,  82, '\0',  /* sTER */
+        115,  82,  71,  66, '\0',  /* sRGB */
+        116,  69,  88, 116, '\0',  /* tEXt */
+        116,  73,  77,  69, '\0',  /* tIME */
+        122,  84,  88, 116, '\0'   /* zTXt */
+      };
+
+      chunk_list = chunks_to_ignore;
+      num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
+   }
+
+   else /* num_chunks_in > 0 */
+   {
+      if (chunk_list == NULL)
+      {
+         /* Prior to 1.6.0 this was silently ignored, now it is an app_error
+          * which can be switched off.
+          */
+         png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
+
+         return;
+      }
+
+      num_chunks = (unsigned int)num_chunks_in;
+   }
+
+   old_num_chunks = png_ptr->num_chunk_list;
+   if (png_ptr->chunk_list == NULL)
+      old_num_chunks = 0;
+
+   /* Since num_chunks is always restricted to UINT_MAX/5 this can't overflow.
+    */
+   if (num_chunks + old_num_chunks > UINT_MAX/5)
+   {
+      png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
+
+      return;
+   }
+
+   /* If these chunks are being reset to the default then no more memory is
+    * required because add_one_chunk above doesn't extend the list if the 'keep'
+    * parameter is the default.
+    */
+   if (keep != 0)
+   {
+      new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
+          5 * (num_chunks + old_num_chunks)));
+
+      if (old_num_chunks > 0)
+         memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+   }
+
+   else if (old_num_chunks > 0)
+      new_list = png_ptr->chunk_list;
+
+   else
+      new_list = NULL;
+
+   /* Add the new chunks together with each one's handling code.  If the chunk
+    * already exists the code is updated, otherwise the chunk is added to the
+    * end.  (In libpng 1.6.0 order no longer matters because this code enforces
+    * the earlier convention that the last setting is the one that is used.)
+    */
+   if (new_list != NULL)
+   {
+      png_const_bytep inlist;
+      png_bytep outlist;
+      unsigned int i;
+
+      for (i=0; i<num_chunks; ++i)
+      {
+         old_num_chunks = add_one_chunk(new_list, old_num_chunks,
+             chunk_list+5*i, keep);
+      }
+
+      /* Now remove any spurious 'default' entries. */
+      num_chunks = 0;
+      for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
+      {
+         if (inlist[4])
+         {
+            if (outlist != inlist)
+               memcpy(outlist, inlist, 5);
+            outlist += 5;
+            ++num_chunks;
+         }
+      }
+
+      /* This means the application has removed all the specialized handling. */
+      if (num_chunks == 0)
+      {
+         if (png_ptr->chunk_list != new_list)
+            png_free(png_ptr, new_list);
+
+         new_list = NULL;
+      }
+   }
+
+   else
+      num_chunks = 0;
+
+   png_ptr->num_chunk_list = num_chunks;
+
+   if (png_ptr->chunk_list != new_list)
+   {
+      if (png_ptr->chunk_list != NULL)
+         png_free(png_ptr, png_ptr->chunk_list);
+
+      png_ptr->chunk_list = new_list;
+   }
+}
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+void PNGAPI
+png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr,
+    png_user_chunk_ptr read_user_chunk_fn)
+{
+   png_debug(1, "in png_set_read_user_chunk_fn");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+   png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_bytepp row_pointers)
+{
+   png_debug1(1, "in %s storage function", "rows");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if (info_ptr->row_pointers != NULL &&
+       (info_ptr->row_pointers != row_pointers))
+      png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
+
+   info_ptr->row_pointers = row_pointers;
+
+   if (row_pointers != NULL)
+      info_ptr->valid |= PNG_INFO_IDAT;
+}
+#endif
+
+void PNGAPI
+png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
+{
+   if (png_ptr == NULL)
+      return;
+
+   if (size == 0 || size > PNG_UINT_31_MAX)
+      png_error(png_ptr, "invalid compression buffer size");
+
+#  ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+   {
+      png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
+      return;
+   }
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+   {
+      if (png_ptr->zowner != 0)
+      {
+         png_warning(png_ptr,
+             "Compression buffer size cannot be changed because it is in use");
+
+         return;
+      }
+
+#ifndef __COVERITY__
+      /* Some compilers complain that this is always false.  However, it
+       * can be true when integer overflow happens.
+       */
+      if (size > ZLIB_IO_MAX)
+      {
+         png_warning(png_ptr,
+             "Compression buffer size limited to system maximum");
+         size = ZLIB_IO_MAX; /* must fit */
+      }
+#endif
+
+      if (size < 6)
+      {
+         /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
+          * if this is permitted.
+          */
+         png_warning(png_ptr,
+             "Compression buffer size cannot be reduced below 6");
+
+         return;
+      }
+
+      if (png_ptr->zbuffer_size != size)
+      {
+         png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+         png_ptr->zbuffer_size = (uInt)size;
+      }
+   }
+#  endif
+}
+
+void PNGAPI
+png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      info_ptr->valid &= (unsigned int)(~mask);
+}
+
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* This function was added to libpng 1.2.6 */
+void PNGAPI
+png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
+    png_uint_32 user_height_max)
+{
+   /* Images with dimensions larger than these limits will be
+    * rejected by png_set_IHDR().  To accept any PNG datastream
+    * regardless of dimensions, set both limits to 0x7fffffff.
+    */
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->user_width_max = user_width_max;
+   png_ptr->user_height_max = user_height_max;
+}
+
+/* This function was added to libpng 1.4.0 */
+void PNGAPI
+png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
+{
+   if (png_ptr != NULL)
+      png_ptr->user_chunk_cache_max = user_chunk_cache_max;
+}
+
+/* This function was added to libpng 1.4.1 */
+void PNGAPI
+png_set_chunk_malloc_max (png_structrp png_ptr,
+    png_alloc_size_t user_chunk_malloc_max)
+{
+   if (png_ptr != NULL)
+      png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
+}
+#endif /* ?SET_USER_LIMITS */
+
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_set_benign_errors(png_structrp png_ptr, int allowed)
+{
+   png_debug(1, "in png_set_benign_errors");
+
+   /* If allowed is 1, png_benign_error() is treated as a warning.
+    *
+    * If allowed is 0, png_benign_error() is treated as an error (which
+    * is the default behavior if png_set_benign_errors() is not called).
+    */
+
+   if (allowed != 0)
+      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
+         PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
+
+   else
+      png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
+         PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
+}
+#endif /* BENIGN_ERRORS */
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   /* Whether to report invalid palette index; added at libng-1.5.10.
+    * It is possible for an indexed (color-type==3) PNG file to contain
+    * pixels with invalid (out-of-range) indexes if the PLTE chunk has
+    * fewer entries than the image's bit-depth would allow. We recover
+    * from this gracefully by filling any incomplete palette with zeros
+    * (opaque black).  By default, when this occurs libpng will issue
+    * a benign error.  This API can be used to override that behavior.
+    */
+void PNGAPI
+png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
+{
+   png_debug(1, "in png_set_check_for_invalid_index");
+
+   if (allowed > 0)
+      png_ptr->num_palette_max = 0;
+
+   else
+      png_ptr->num_palette_max = -1;
+}
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) || \
+    defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
+/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
+ * and if invalid, correct the keyword rather than discarding the entire
+ * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
+ * length, forbids leading or trailing whitespace, multiple internal spaces,
+ * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
+ *
+ * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
+ * trailing '\0').  If this routine returns 0 then there was no keyword, or a
+ * valid one could not be generated, and the caller must png_error.
+ */
+png_uint_32 /* PRIVATE */
+png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
+{
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_const_charp orig_key = key;
+#endif
+   png_uint_32 key_len = 0;
+   int bad_character = 0;
+   int space = 1;
+
+   png_debug(1, "in png_check_keyword");
+
+   if (key == NULL)
+   {
+      *new_key = 0;
+      return 0;
+   }
+
+   while (*key && key_len < 79)
+   {
+      png_byte ch = (png_byte)*key++;
+
+      if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
+      {
+         *new_key++ = ch; ++key_len; space = 0;
+      }
+
+      else if (space == 0)
+      {
+         /* A space or an invalid character when one wasn't seen immediately
+          * before; output just a space.
+          */
+         *new_key++ = 32; ++key_len; space = 1;
+
+         /* If the character was not a space then it is invalid. */
+         if (ch != 32)
+            bad_character = ch;
+      }
+
+      else if (bad_character == 0)
+         bad_character = ch; /* just skip it, record the first error */
+   }
+
+   if (key_len > 0 && space != 0) /* trailing space */
+   {
+      --key_len; --new_key;
+      if (bad_character == 0)
+         bad_character = 32;
+   }
+
+   /* Terminate the keyword */
+   *new_key = 0;
+
+   if (key_len == 0)
+      return 0;
+
+#ifdef PNG_WARNINGS_SUPPORTED
+   /* Try to only output one warning per keyword: */
+   if (*key != 0) /* keyword too long */
+      png_warning(png_ptr, "keyword truncated");
+
+   else if (bad_character != 0)
+   {
+      PNG_WARNING_PARAMETERS(p)
+
+      png_warning_parameter(p, 1, orig_key);
+      png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
+
+      png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
+   }
+#else /* !WARNINGS */
+   PNG_UNUSED(png_ptr)
+#endif /* !WARNINGS */
+
+   return key_len;
+}
+#endif /* TEXT || pCAL || iCCP || sPLT */
+#endif /* READ || WRITE */
diff --git a/xs/src/png/libpng/pngstruct.h b/xs/src/png/libpng/pngstruct.h
new file mode 100644
index 000000000..d83f97125
--- /dev/null
+++ b/xs/src/png/libpng/pngstruct.h
@@ -0,0 +1,483 @@
+
+/* pngstruct.h - header file for PNG reference library
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+/* The structure that holds the information to read and write PNG files.
+ * The only people who need to care about what is inside of this are the
+ * people who will be modifying the library for their own special needs.
+ * It should NOT be accessed directly by an application.
+ */
+
+#ifndef PNGSTRUCT_H
+#define PNGSTRUCT_H
+/* zlib.h defines the structure z_stream, an instance of which is included
+ * in this structure and is required for decompressing the LZ compressed
+ * data in PNG files.
+ */
+#ifndef ZLIB_CONST
+   /* We must ensure that zlib uses 'const' in declarations. */
+#  define ZLIB_CONST
+#endif
+#include "zlib.h"
+#ifdef const
+   /* zlib.h sometimes #defines const to nothing, undo this. */
+#  undef const
+#endif
+
+/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
+ * with older builds.
+ */
+#if ZLIB_VERNUM < 0x1260
+#  define PNGZ_MSG_CAST(s) png_constcast(char*,s)
+#  define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#else
+#  define PNGZ_MSG_CAST(s) (s)
+#  define PNGZ_INPUT_CAST(b) (b)
+#endif
+
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once.  This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximuum for png_size_t.  The value can be overriden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+#  define ZLIB_IO_MAX ((uInt)-1)
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+/* The type of a compression buffer list used by the write code. */
+typedef struct png_compression_buffer
+{
+   struct png_compression_buffer *next;
+   png_byte                       output[1]; /* actually zbuf_size */
+} png_compression_buffer, *png_compression_bufferp;
+
+#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
+   (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
+#endif
+
+/* Colorspace support; structures used in png_struct, png_info and in internal
+ * functions to hold and communicate information about the color space.
+ *
+ * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
+ * colorspace corrections, otherwise all the colorspace information can be
+ * skipped and the size of libpng can be reduced (significantly) by compiling
+ * out the colorspace support.
+ */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* The chromaticities of the red, green and blue colorants and the chromaticity
+ * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
+ */
+typedef struct png_xy
+{
+   png_fixed_point redx, redy;
+   png_fixed_point greenx, greeny;
+   png_fixed_point bluex, bluey;
+   png_fixed_point whitex, whitey;
+} png_xy;
+
+/* The same data as above but encoded as CIE XYZ values.  When this data comes
+ * from chromaticities the sum of the Y values is assumed to be 1.0
+ */
+typedef struct png_XYZ
+{
+   png_fixed_point red_X, red_Y, red_Z;
+   png_fixed_point green_X, green_Y, green_Z;
+   png_fixed_point blue_X, blue_Y, blue_Z;
+} png_XYZ;
+#endif /* COLORSPACE */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+/* A colorspace is all the above plus, potentially, profile information;
+ * however at present libpng does not use the profile internally so it is only
+ * stored in the png_info struct (if iCCP is supported.)  The rendering intent
+ * is retained here and is checked.
+ *
+ * The file gamma encoding information is also stored here and gamma correction
+ * is done by libpng, whereas color correction must currently be done by the
+ * application.
+ */
+typedef struct png_colorspace
+{
+#ifdef PNG_GAMMA_SUPPORTED
+   png_fixed_point gamma;        /* File gamma */
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+   png_xy      end_points_xy;    /* End points as chromaticities */
+   png_XYZ     end_points_XYZ;   /* End points as CIE XYZ colorant values */
+   png_uint_16 rendering_intent; /* Rendering intent of a profile */
+#endif
+
+   /* Flags are always defined to simplify the code. */
+   png_uint_16 flags;            /* As defined below */
+} png_colorspace, * PNG_RESTRICT png_colorspacerp;
+
+typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
+
+/* General flags for the 'flags' field */
+#define PNG_COLORSPACE_HAVE_GAMMA           0x0001
+#define PNG_COLORSPACE_HAVE_ENDPOINTS       0x0002
+#define PNG_COLORSPACE_HAVE_INTENT          0x0004
+#define PNG_COLORSPACE_FROM_gAMA            0x0008
+#define PNG_COLORSPACE_FROM_cHRM            0x0010
+#define PNG_COLORSPACE_FROM_sRGB            0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB         0x0080 /* exact match on profile */
+#define PNG_COLORSPACE_INVALID              0x8000
+#define PNG_COLORSPACE_CANCEL(flags)        (0xffff ^ (flags))
+#endif /* COLORSPACE || GAMMA */
+
+struct png_struct_def
+{
+#ifdef PNG_SETJMP_SUPPORTED
+   jmp_buf jmp_buf_local;     /* New name in 1.6.0 for jmp_buf in png_struct */
+   png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
+   jmp_buf *jmp_buf_ptr;      /* passed to longjmp_fn */
+   size_t jmp_buf_size;       /* size of the above, if allocated */
+#endif
+   png_error_ptr error_fn;    /* function for printing errors and aborting */
+#ifdef PNG_WARNINGS_SUPPORTED
+   png_error_ptr warning_fn;  /* function for printing warnings */
+#endif
+   png_voidp error_ptr;       /* user supplied struct for error functions */
+   png_rw_ptr write_data_fn;  /* function for writing output data */
+   png_rw_ptr read_data_fn;   /* function for reading input data */
+   png_voidp io_ptr;          /* ptr to application struct for I/O functions */
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   png_user_transform_ptr write_user_transform_fn; /* user write transform */
+#endif
+
+/* These were added in libpng-1.0.2 */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   png_voidp user_transform_ptr; /* user supplied struct for user transform */
+   png_byte user_transform_depth;    /* bit depth of user transformed pixels */
+   png_byte user_transform_channels; /* channels in user transformed pixels */
+#endif
+#endif
+
+   png_uint_32 mode;          /* tells us where we are in the PNG file */
+   png_uint_32 flags;         /* flags indicating various things to libpng */
+   png_uint_32 transformations; /* which transformations to perform */
+
+   png_uint_32 zowner;        /* ID (chunk type) of zstream owner, 0 if none */
+   z_stream    zstream;       /* decompression structure */
+
+#ifdef PNG_WRITE_SUPPORTED
+   png_compression_bufferp zbuffer_list; /* Created on demand during write */
+   uInt                    zbuffer_size; /* size of the actual buffer */
+
+   int zlib_level;            /* holds zlib compression level */
+   int zlib_method;           /* holds zlib compression method */
+   int zlib_window_bits;      /* holds zlib compression window bits */
+   int zlib_mem_level;        /* holds zlib compression memory level */
+   int zlib_strategy;         /* holds zlib compression strategy */
+#endif
+/* Added at libpng 1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   int zlib_text_level;            /* holds zlib compression level */
+   int zlib_text_method;           /* holds zlib compression method */
+   int zlib_text_window_bits;      /* holds zlib compression window bits */
+   int zlib_text_mem_level;        /* holds zlib compression memory level */
+   int zlib_text_strategy;         /* holds zlib compression strategy */
+#endif
+/* End of material added at libpng 1.5.4 */
+/* Added at libpng 1.6.0 */
+#ifdef PNG_WRITE_SUPPORTED
+   int zlib_set_level;        /* Actual values set into the zstream on write */
+   int zlib_set_method;
+   int zlib_set_window_bits;
+   int zlib_set_mem_level;
+   int zlib_set_strategy;
+#endif
+
+   png_uint_32 width;         /* width of image in pixels */
+   png_uint_32 height;        /* height of image in pixels */
+   png_uint_32 num_rows;      /* number of rows in current pass */
+   png_uint_32 usr_width;     /* width of row at start of write */
+   png_size_t rowbytes;       /* size of row in bytes */
+   png_uint_32 iwidth;        /* width of current interlaced row in pixels */
+   png_uint_32 row_number;    /* current row in interlace pass */
+   png_uint_32 chunk_name;    /* PNG_CHUNK() id of current chunk */
+   png_bytep prev_row;        /* buffer to save previous (unfiltered) row.
+                               * While reading this is a pointer into
+                               * big_prev_row; while writing it is separately
+                               * allocated if needed.
+                               */
+   png_bytep row_buf;         /* buffer to save current (unfiltered) row.
+                               * While reading, this is a pointer into
+                               * big_row_buf; while writing it is separately
+                               * allocated.
+                               */
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_bytep try_row;    /* buffer to save trial row when filtering */
+   png_bytep tst_row;    /* buffer to save best trial row when filtering */
+#endif
+   png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
+
+   png_uint_32 idat_size;     /* current IDAT size for read */
+   png_uint_32 crc;           /* current chunk CRC value */
+   png_colorp palette;        /* palette from the input file */
+   png_uint_16 num_palette;   /* number of color entries in palette */
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   int num_palette_max;       /* maximum palette index found in IDAT */
+#endif
+
+   png_uint_16 num_trans;     /* number of transparency values */
+   png_byte compression;      /* file compression type (always 0) */
+   png_byte filter;           /* file filter type (always 0) */
+   png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
+   png_byte pass;             /* current interlace pass (0 - 6) */
+   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ in png.h ) */
+   png_byte color_type;       /* color type of file */
+   png_byte bit_depth;        /* bit depth of file */
+   png_byte usr_bit_depth;    /* bit depth of users row: write only */
+   png_byte pixel_depth;      /* number of bits per pixel */
+   png_byte channels;         /* number of channels in file */
+#ifdef PNG_WRITE_SUPPORTED
+   png_byte usr_channels;     /* channels at start of write: write only */
+#endif
+   png_byte sig_bytes;        /* magic bytes read/written from start of file */
+   png_byte maximum_pixel_depth;
+                              /* pixel depth used for the row buffers */
+   png_byte transformed_pixel_depth;
+                              /* pixel depth after read/write transforms */
+#if ZLIB_VERNUM >= 0x1240
+   png_byte zstream_start;    /* at start of an input zlib stream */
+#endif /* Zlib >= 1.2.4 */
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+   png_uint_16 filler;           /* filler bytes for pixel expansion */
+#endif
+
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   png_byte background_gamma_type;
+   png_fixed_point background_gamma;
+   png_color_16 background;   /* background color in screen gamma space */
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   png_color_16 background_1; /* background normalized to gamma 1.0 */
+#endif
+#endif /* bKGD */
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_flush_ptr output_flush_fn; /* Function for flushing output */
+   png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
+   png_uint_32 flush_rows;    /* number of rows written since last flush */
+#endif
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   int gamma_shift;      /* number of "insignificant" bits in 16-bit gamma */
+   png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
+
+   png_bytep gamma_table;     /* gamma table for 8-bit depth files */
+   png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
+   defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_bytep gamma_from_1;    /* converts from 1.0 to screen */
+   png_bytep gamma_to_1;      /* converts from file to 1.0 */
+   png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
+   png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
+   png_color_8 sig_bit;       /* significant bits in each available channel */
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+   png_color_8 shift;         /* shift for significant bit tranformation */
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+   png_bytep trans_alpha;           /* alpha values for paletted files */
+   png_color_16 trans_color;  /* transparent color for non-paletted files */
+#endif
+
+   png_read_status_ptr read_row_fn;   /* called after each row is decoded */
+   png_write_status_ptr write_row_fn; /* called after each row is encoded */
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+   png_progressive_info_ptr info_fn; /* called after header data fully read */
+   png_progressive_row_ptr row_fn;   /* called after a prog. row is decoded */
+   png_progressive_end_ptr end_fn;   /* called after image is complete */
+   png_bytep save_buffer_ptr;        /* current location in save_buffer */
+   png_bytep save_buffer;            /* buffer for previously read data */
+   png_bytep current_buffer_ptr;     /* current location in current_buffer */
+   png_bytep current_buffer;         /* buffer for recently used data */
+   png_uint_32 push_length;          /* size of current input chunk */
+   png_uint_32 skip_length;          /* bytes to skip in input data */
+   png_size_t save_buffer_size;      /* amount of data now in save_buffer */
+   png_size_t save_buffer_max;       /* total size of save_buffer */
+   png_size_t buffer_size;           /* total amount of available input data */
+   png_size_t current_buffer_size;   /* amount of data now in current_buffer */
+   int process_mode;                 /* what push library is currently doing */
+   int cur_palette;                  /* current push library palette index */
+
+#endif /* PROGRESSIVE_READ */
+
+#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
+/* For the Borland special 64K segment handler */
+   png_bytepp offset_table_ptr;
+   png_bytep offset_table;
+   png_uint_16 offset_table_number;
+   png_uint_16 offset_table_count;
+   png_uint_16 offset_table_count_free;
+#endif
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+   png_bytep palette_lookup; /* lookup table for quantizing */
+   png_bytep quantize_index; /* index translation for palette files */
+#endif
+
+/* Options */
+#ifdef PNG_SET_OPTION_SUPPORTED
+   png_uint_32 options;           /* On/off state (up to 16 options) */
+#endif
+
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng-1.7 */
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+   char time_buffer[29]; /* String to hold RFC 1123 time text */
+#endif
+#endif
+
+/* New members added in libpng-1.0.6 */
+
+   png_uint_32 free_me;    /* flags items libpng is responsible for freeing */
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+   png_voidp user_chunk_ptr;
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
+#endif
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   int          unknown_default; /* As PNG_HANDLE_* */
+   unsigned int num_chunk_list;  /* Number of entries in the list */
+   png_bytep    chunk_list;      /* List of png_byte[5]; the textual chunk name
+                                  * followed by a PNG_HANDLE_* byte */
+#endif
+
+/* New members added in libpng-1.0.3 */
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   png_byte rgb_to_gray_status;
+   /* Added in libpng 1.5.5 to record setting of coefficients: */
+   png_byte rgb_to_gray_coefficients_set;
+   /* These were changed from png_byte in libpng-1.0.6 */
+   png_uint_16 rgb_to_gray_red_coeff;
+   png_uint_16 rgb_to_gray_green_coeff;
+   /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
+#endif
+
+/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* Changed from png_byte to png_uint_32 at version 1.2.0 */
+   png_uint_32 mng_features_permitted;
+#endif
+
+/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_byte filter_type;
+#endif
+
+/* New members added in libpng-1.2.0 */
+
+/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_voidp mem_ptr;             /* user supplied struct for mem functions */
+   png_malloc_ptr malloc_fn;      /* function for allocating memory */
+   png_free_ptr free_fn;          /* function for freeing memory */
+#endif
+
+/* New member added in libpng-1.0.13 and 1.2.0 */
+   png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
+
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* The following three members were added at version 1.0.14 and 1.2.4 */
+   png_bytep quantize_sort;          /* working sort array */
+   png_bytep index_to_palette;       /* where the original index currently is
+                                        in the palette */
+   png_bytep palette_to_index;       /* which original index points to this
+                                         palette color */
+#endif
+
+/* New members added in libpng-1.0.16 and 1.2.6 */
+   png_byte compression_type;
+
+#ifdef PNG_USER_LIMITS_SUPPORTED
+   png_uint_32 user_width_max;
+   png_uint_32 user_height_max;
+
+   /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
+    * chunks that can be stored (0 means unlimited).
+    */
+   png_uint_32 user_chunk_cache_max;
+
+   /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
+    * can occupy when decompressed.  0 means unlimited.
+    */
+   png_alloc_size_t user_chunk_malloc_max;
+#endif
+
+/* New member added in libpng-1.0.25 and 1.2.17 */
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* Temporary storage for unknown chunk that the library doesn't recognize,
+    * used while reading the chunk.
+    */
+   png_unknown_chunk unknown_chunk;
+#endif
+
+/* New member added in libpng-1.2.26 */
+  png_size_t old_big_row_buf_size;
+
+#ifdef PNG_READ_SUPPORTED
+/* New member added in libpng-1.2.30 */
+  png_bytep        read_buffer;      /* buffer for reading chunk data */
+  png_alloc_size_t read_buffer_size; /* current size of the buffer */
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+  uInt             IDAT_read_size;   /* limit on read buffer size for IDAT */
+#endif
+
+#ifdef PNG_IO_STATE_SUPPORTED
+/* New member added in libpng-1.4.0 */
+   png_uint_32 io_state;
+#endif
+
+/* New member added in libpng-1.5.6 */
+   png_bytep big_prev_row;
+
+/* New member added in libpng-1.5.7 */
+   void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
+      png_bytep row, png_const_bytep prev_row);
+
+#ifdef PNG_READ_SUPPORTED
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   png_colorspace   colorspace;
+#endif
+#endif
+};
+#endif /* PNGSTRUCT_H */
diff --git a/xs/src/png/libpng/pngtest.c b/xs/src/png/libpng/pngtest.c
new file mode 100644
index 000000000..9d5075791
--- /dev/null
+++ b/xs/src/png/libpng/pngtest.c
@@ -0,0 +1,2156 @@
+
+/* pngtest.c - a simple test program to test libpng
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This program reads in a PNG image, writes it out again, and then
+ * compares the two files.  If the files are identical, this shows that
+ * the basic chunk handling, filtering, and (de)compression code is working
+ * properly.  It does not currently test all of the transforms, although
+ * it probably should.
+ *
+ * The program will report "FAIL" in certain legitimate cases:
+ * 1) when the compression level or filter selection method is changed.
+ * 2) when the maximum IDAT size (PNG_ZBUF_SIZE in pngconf.h) is not 8192.
+ * 3) unknown unsafe-to-copy ancillary chunks or unknown critical chunks
+ *    exist in the input file.
+ * 4) others not listed here...
+ * In these cases, it is best to check with another tool such as "pngcheck"
+ * to see what the differences between the two files are.
+ *
+ * If a filename is given on the command-line, then this file is used
+ * for the input, rather than the default "pngtest.png".  This allows
+ * testing a wide variety of files easily.  You can also test a number
+ * of files at once by typing "pngtest -m file1.png file2.png ..."
+ */
+
+#define _POSIX_SOURCE 1
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Defined so I can write to a file on gui/windowing platforms */
+/*  #define STDERR stderr  */
+#define STDERR stdout   /* For DOS */
+
+#include "png.h"
+
+/* Known chunks that exist in pngtest.png must be supported or pngtest will fail
+ * simply as a result of re-ordering them.  This may be fixed in 1.7
+ *
+ * pngtest allocates a single row buffer for each row and overwrites it,
+ * therefore if the write side doesn't support the writing of interlaced images
+ * nothing can be done for an interlaced image (and the code below will fail
+ * horribly trying to write extra data after writing garbage).
+ */
+#if defined PNG_READ_SUPPORTED && /* else nothing can be done */\
+   defined PNG_READ_bKGD_SUPPORTED &&\
+   defined PNG_READ_cHRM_SUPPORTED &&\
+   defined PNG_READ_gAMA_SUPPORTED &&\
+   defined PNG_READ_oFFs_SUPPORTED &&\
+   defined PNG_READ_pCAL_SUPPORTED &&\
+   defined PNG_READ_pHYs_SUPPORTED &&\
+   defined PNG_READ_sBIT_SUPPORTED &&\
+   defined PNG_READ_sCAL_SUPPORTED &&\
+   defined PNG_READ_sRGB_SUPPORTED &&\
+   defined PNG_READ_sPLT_SUPPORTED &&\
+   defined PNG_READ_tEXt_SUPPORTED &&\
+   defined PNG_READ_tIME_SUPPORTED &&\
+   defined PNG_READ_zTXt_SUPPORTED &&\
+   (defined PNG_WRITE_INTERLACING_SUPPORTED || PNG_LIBPNG_VER >= 10700)
+
+#ifdef PNG_ZLIB_HEADER
+#  include PNG_ZLIB_HEADER /* defined by pnglibconf.h from 1.7 */
+#else
+#  include "zlib.h"
+#endif
+
+/* Copied from pngpriv.h but only used in error messages below. */
+#ifndef PNG_ZBUF_SIZE
+#  define PNG_ZBUF_SIZE 8192
+#endif
+#define FCLOSE(file) fclose(file)
+
+#ifndef PNG_STDIO_SUPPORTED
+typedef FILE                * png_FILE_p;
+#endif
+
+/* Makes pngtest verbose so we can find problems. */
+#ifndef PNG_DEBUG
+#  define PNG_DEBUG 0
+#endif
+
+#if PNG_DEBUG > 1
+#  define pngtest_debug(m)        ((void)fprintf(stderr, m "\n"))
+#  define pngtest_debug1(m,p1)    ((void)fprintf(stderr, m "\n", p1))
+#  define pngtest_debug2(m,p1,p2) ((void)fprintf(stderr, m "\n", p1, p2))
+#else
+#  define pngtest_debug(m)        ((void)0)
+#  define pngtest_debug1(m,p1)    ((void)0)
+#  define pngtest_debug2(m,p1,p2) ((void)0)
+#endif
+
+#if !PNG_DEBUG
+#  define SINGLE_ROWBUF_ALLOC  /* Makes buffer overruns easier to nail */
+#endif
+
+#ifndef PNG_UNUSED
+#  define PNG_UNUSED(param) (void)param;
+#endif
+
+/* Turn on CPU timing
+#define PNGTEST_TIMING
+*/
+
+#ifndef PNG_FLOATING_POINT_SUPPORTED
+#undef PNGTEST_TIMING
+#endif
+
+#ifdef PNGTEST_TIMING
+static float t_start, t_stop, t_decode, t_encode, t_misc;
+#include <time.h>
+#endif
+
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+#define PNG_tIME_STRING_LENGTH 29
+static int tIME_chunk_present = 0;
+static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present";
+
+#if PNG_LIBPNG_VER < 10619
+#define png_convert_to_rfc1123_buffer(ts, t) tIME_to_str(read_ptr, ts, t)
+
+static int
+tIME_to_str(png_structp png_ptr, png_charp ts, png_const_timep t)
+{
+   png_const_charp str = png_convert_to_rfc1123(png_ptr, t);
+
+   if (str == NULL)
+       return 0;
+
+   strcpy(ts, str);
+   return 1;
+}
+#endif /* older libpng */
+#endif
+
+static int verbose = 0;
+static int strict = 0;
+static int relaxed = 0;
+static int xfail = 0;
+static int unsupported_chunks = 0; /* chunk unsupported by libpng in input */
+static int error_count = 0; /* count calls to png_error */
+static int warning_count = 0; /* count calls to png_warning */
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) png_ptr->jmpbuf
+#endif
+
+/* Defines for unknown chunk handling if required. */
+#ifndef PNG_HANDLE_CHUNK_ALWAYS
+#  define PNG_HANDLE_CHUNK_ALWAYS       3
+#endif
+#ifndef PNG_HANDLE_CHUNK_IF_SAFE
+#  define PNG_HANDLE_CHUNK_IF_SAFE      2
+#endif
+
+/* Utility to save typing/errors, the argument must be a name */
+#define MEMZERO(var) ((void)memset(&var, 0, sizeof var))
+
+/* Example of using row callbacks to make a simple progress meter */
+static int status_pass = 1;
+static int status_dots_requested = 0;
+static int status_dots = 1;
+
+static void PNGCBAPI
+read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
+{
+   if (png_ptr == NULL || row_number > PNG_UINT_31_MAX)
+      return;
+
+   if (status_pass != pass)
+   {
+      fprintf(stdout, "\n Pass %d: ", pass);
+      status_pass = pass;
+      status_dots = 31;
+   }
+
+   status_dots--;
+
+   if (status_dots == 0)
+   {
+      fprintf(stdout, "\n         ");
+      status_dots=30;
+   }
+
+   fprintf(stdout, "r");
+}
+
+#ifdef PNG_WRITE_SUPPORTED
+static void PNGCBAPI
+write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
+{
+   if (png_ptr == NULL || row_number > PNG_UINT_31_MAX || pass > 7)
+      return;
+
+   fprintf(stdout, "w");
+}
+#endif
+
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+/* Example of using a user transform callback (doesn't do anything at present).
+ */
+static void PNGCBAPI
+read_user_callback(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(row_info)
+   PNG_UNUSED(data)
+}
+#endif
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+/* Example of using user transform callback (we don't transform anything,
+ * but merely count the zero samples)
+ */
+
+static png_uint_32 zero_samples;
+
+static void PNGCBAPI
+count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+   png_bytep dp = data;
+   if (png_ptr == NULL)
+      return;
+
+   /* Contents of row_info:
+    *  png_uint_32 width      width of row
+    *  png_uint_32 rowbytes   number of bytes in row
+    *  png_byte color_type    color type of pixels
+    *  png_byte bit_depth     bit depth of samples
+    *  png_byte channels      number of channels (1-4)
+    *  png_byte pixel_depth   bits per pixel (depth*channels)
+    */
+
+   /* Counts the number of zero samples (or zero pixels if color_type is 3 */
+
+   if (row_info->color_type == 0 || row_info->color_type == 3)
+   {
+      int pos = 0;
+      png_uint_32 n, nstop;
+
+      for (n = 0, nstop=row_info->width; n<nstop; n++)
+      {
+         if (row_info->bit_depth == 1)
+         {
+            if (((*dp << pos++ ) & 0x80) == 0)
+               zero_samples++;
+
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
+
+         if (row_info->bit_depth == 2)
+         {
+            if (((*dp << (pos+=2)) & 0xc0) == 0)
+               zero_samples++;
+
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
+
+         if (row_info->bit_depth == 4)
+         {
+            if (((*dp << (pos+=4)) & 0xf0) == 0)
+               zero_samples++;
+
+            if (pos == 8)
+            {
+               pos = 0;
+               dp++;
+            }
+         }
+
+         if (row_info->bit_depth == 8)
+            if (*dp++ == 0)
+               zero_samples++;
+
+         if (row_info->bit_depth == 16)
+         {
+            if ((*dp | *(dp+1)) == 0)
+               zero_samples++;
+            dp+=2;
+         }
+      }
+   }
+   else /* Other color types */
+   {
+      png_uint_32 n, nstop;
+      int channel;
+      int color_channels = row_info->channels;
+      if (row_info->color_type > 3)
+         color_channels--;
+
+      for (n = 0, nstop=row_info->width; n<nstop; n++)
+      {
+         for (channel = 0; channel < color_channels; channel++)
+         {
+            if (row_info->bit_depth == 8)
+               if (*dp++ == 0)
+                  zero_samples++;
+
+            if (row_info->bit_depth == 16)
+            {
+               if ((*dp | *(dp+1)) == 0)
+                  zero_samples++;
+
+               dp+=2;
+            }
+         }
+         if (row_info->color_type > 3)
+         {
+            dp++;
+            if (row_info->bit_depth == 16)
+               dp++;
+         }
+      }
+   }
+}
+#endif /* WRITE_USER_TRANSFORM */
+
+#ifndef PNG_STDIO_SUPPORTED
+/* START of code to validate stdio-free compilation */
+/* These copies of the default read/write functions come from pngrio.c and
+ * pngwio.c.  They allow "don't include stdio" testing of the library.
+ * This is the function that does the actual reading of data.  If you are
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
+
+#ifdef PNG_IO_STATE_SUPPORTED
+void
+pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
+    png_uint_32 io_op);
+void
+pngtest_check_io_state(png_structp png_ptr, png_size_t data_length,
+    png_uint_32 io_op)
+{
+   png_uint_32 io_state = png_get_io_state(png_ptr);
+   int err = 0;
+
+   /* Check if the current operation (reading / writing) is as expected. */
+   if ((io_state & PNG_IO_MASK_OP) != io_op)
+      png_error(png_ptr, "Incorrect operation in I/O state");
+
+   /* Check if the buffer size specific to the current location
+    * (file signature / header / data / crc) is as expected.
+    */
+   switch (io_state & PNG_IO_MASK_LOC)
+   {
+   case PNG_IO_SIGNATURE:
+      if (data_length > 8)
+         err = 1;
+      break;
+   case PNG_IO_CHUNK_HDR:
+      if (data_length != 8)
+         err = 1;
+      break;
+   case PNG_IO_CHUNK_DATA:
+      break;  /* no restrictions here */
+   case PNG_IO_CHUNK_CRC:
+      if (data_length != 4)
+         err = 1;
+      break;
+   default:
+      err = 1;  /* uninitialized */
+   }
+   if (err != 0)
+      png_error(png_ptr, "Bad I/O state or buffer size");
+}
+#endif
+
+static void PNGCBAPI
+pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check = 0;
+   png_voidp io_ptr;
+
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   io_ptr = png_get_io_ptr(png_ptr);
+   if (io_ptr != NULL)
+   {
+      check = fread(data, 1, length, (png_FILE_p)io_ptr);
+   }
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Read Error");
+   }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_READING);
+#endif
+}
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+static void PNGCBAPI
+pngtest_flush(png_structp png_ptr)
+{
+   /* Do nothing; fflush() is said to be just a waste of energy. */
+   PNG_UNUSED(png_ptr)   /* Stifle compiler warning */
+}
+#endif
+
+/* This is the function that does the actual writing of data.  If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+static void PNGCBAPI
+pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   check = fwrite(data, 1, length, (png_FILE_p)png_get_io_ptr(png_ptr));
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
+#endif
+}
+#endif /* !STDIO */
+
+/* This function is called when there is a warning, but the library thinks
+ * it can continue anyway.  Replacement functions don't have to do anything
+ * here if you don't want to.  In the default configuration, png_ptr is
+ * not used, but it is passed in case it may be useful.
+ */
+typedef struct
+{
+   PNG_CONST char *file_name;
+}  pngtest_error_parameters;
+
+static void PNGCBAPI
+pngtest_warning(png_structp png_ptr, png_const_charp message)
+{
+   PNG_CONST char *name = "UNKNOWN (ERROR!)";
+   pngtest_error_parameters *test =
+      (pngtest_error_parameters*)png_get_error_ptr(png_ptr);
+
+   ++warning_count;
+
+   if (test != NULL && test->file_name != NULL)
+      name = test->file_name;
+
+   fprintf(STDERR, "\n%s: libpng warning: %s\n", name, message);
+}
+
+/* This is the default error handling function.  Note that replacements for
+ * this function MUST NOT RETURN, or the program will likely crash.  This
+ * function is used by default, or if the program supplies NULL for the
+ * error function pointer in png_set_error_fn().
+ */
+static void PNGCBAPI
+pngtest_error(png_structp png_ptr, png_const_charp message)
+{
+   ++error_count;
+
+   pngtest_warning(png_ptr, message);
+   /* We can return because png_error calls the default handler, which is
+    * actually OK in this case.
+    */
+}
+
+/* END of code to validate stdio-free compilation */
+
+/* START of code to validate memory allocation and deallocation */
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+
+/* Allocate memory.  For reasonable files, size should never exceed
+ * 64K.  However, zlib may allocate more than 64K if you don't tell
+ * it not to.  See zconf.h and png.h for more information.  zlib does
+ * need to allocate exactly 64K, so whatever you call here must
+ * have the ability to do that.
+ *
+ * This piece of code can be compiled to validate max 64K allocations
+ * by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K.
+ */
+typedef struct memory_information
+{
+   png_alloc_size_t          size;
+   png_voidp                 pointer;
+   struct memory_information *next;
+} memory_information;
+typedef memory_information *memory_infop;
+
+static memory_infop pinformation = NULL;
+static int current_allocation = 0;
+static int maximum_allocation = 0;
+static int total_allocation = 0;
+static int num_allocations = 0;
+
+png_voidp PNGCBAPI png_debug_malloc PNGARG((png_structp png_ptr,
+    png_alloc_size_t size));
+void PNGCBAPI png_debug_free PNGARG((png_structp png_ptr, png_voidp ptr));
+
+png_voidp
+PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size)
+{
+
+   /* png_malloc has already tested for NULL; png_create_struct calls
+    * png_debug_malloc directly, with png_ptr == NULL which is OK
+    */
+
+   if (size == 0)
+      return (NULL);
+
+   /* This calls the library allocator twice, once to get the requested
+      buffer and once to get a new free list entry. */
+   {
+      /* Disable malloc_fn and free_fn */
+      memory_infop pinfo;
+      png_set_mem_fn(png_ptr, NULL, NULL, NULL);
+      pinfo = (memory_infop)png_malloc(png_ptr,
+          (sizeof *pinfo));
+      pinfo->size = size;
+      current_allocation += size;
+      total_allocation += size;
+      num_allocations ++;
+
+      if (current_allocation > maximum_allocation)
+         maximum_allocation = current_allocation;
+
+      pinfo->pointer = png_malloc(png_ptr, size);
+      /* Restore malloc_fn and free_fn */
+
+      png_set_mem_fn(png_ptr,
+          NULL, png_debug_malloc, png_debug_free);
+
+      if (size != 0 && pinfo->pointer == NULL)
+      {
+         current_allocation -= size;
+         total_allocation -= size;
+         png_error(png_ptr,
+           "out of memory in pngtest->png_debug_malloc");
+      }
+
+      pinfo->next = pinformation;
+      pinformation = pinfo;
+      /* Make sure the caller isn't assuming zeroed memory. */
+      memset(pinfo->pointer, 0xdd, pinfo->size);
+
+      if (verbose != 0)
+         printf("png_malloc %lu bytes at %p\n", (unsigned long)size,
+             pinfo->pointer);
+
+      return (png_voidp)(pinfo->pointer);
+   }
+}
+
+/* Free a pointer.  It is removed from the list at the same time. */
+void PNGCBAPI
+png_debug_free(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL)
+      fprintf(STDERR, "NULL pointer to png_debug_free.\n");
+
+   if (ptr == 0)
+   {
+#if 0 /* This happens all the time. */
+      fprintf(STDERR, "WARNING: freeing NULL pointer\n");
+#endif
+      return;
+   }
+
+   /* Unlink the element from the list. */
+   if (pinformation != NULL)
+   {
+      memory_infop *ppinfo = &pinformation;
+
+      for (;;)
+      {
+         memory_infop pinfo = *ppinfo;
+
+         if (pinfo->pointer == ptr)
+         {
+            *ppinfo = pinfo->next;
+            current_allocation -= pinfo->size;
+            if (current_allocation < 0)
+               fprintf(STDERR, "Duplicate free of memory\n");
+            /* We must free the list element too, but first kill
+               the memory that is to be freed. */
+            memset(ptr, 0x55, pinfo->size);
+            free(pinfo);
+            pinfo = NULL;
+            break;
+         }
+
+         if (pinfo->next == NULL)
+         {
+            fprintf(STDERR, "Pointer %p not found\n", ptr);
+            break;
+         }
+
+         ppinfo = &pinfo->next;
+      }
+   }
+
+   /* Finally free the data. */
+   if (verbose != 0)
+      printf("Freeing %p\n", ptr);
+
+   if (ptr != NULL)
+      free(ptr);
+   ptr = NULL;
+}
+#endif /* USER_MEM && DEBUG */
+/* END of code to test memory allocation/deallocation */
+
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+/* Demonstration of user chunk support of the sTER and vpAg chunks */
+
+/* (sTER is a public chunk not yet known by libpng.  vpAg is a private
+chunk used in ImageMagick to store "virtual page" size).  */
+
+static struct user_chunk_data
+{
+   png_const_infop info_ptr;
+   png_uint_32     vpAg_width, vpAg_height;
+   png_byte        vpAg_units;
+   png_byte        sTER_mode;
+   int             location[2];
+}
+user_chunk_data;
+
+/* Used for location and order; zero means nothing. */
+#define have_sTER   0x01
+#define have_vpAg   0x02
+#define before_PLTE 0x10
+#define before_IDAT 0x20
+#define after_IDAT  0x40
+
+static void
+init_callback_info(png_const_infop info_ptr)
+{
+   MEMZERO(user_chunk_data);
+   user_chunk_data.info_ptr = info_ptr;
+}
+
+static int
+set_location(png_structp png_ptr, struct user_chunk_data *data, int what)
+{
+   int location;
+
+   if ((data->location[0] & what) != 0 || (data->location[1] & what) != 0)
+      return 0; /* already have one of these */
+
+   /* Find where we are (the code below zeroes info_ptr to indicate that the
+    * chunks before the first IDAT have been read.)
+    */
+   if (data->info_ptr == NULL) /* after IDAT */
+      location = what | after_IDAT;
+
+   else if (png_get_valid(png_ptr, data->info_ptr, PNG_INFO_PLTE) != 0)
+      location = what | before_IDAT;
+
+   else
+      location = what | before_PLTE;
+
+   if (data->location[0] == 0)
+      data->location[0] = location;
+
+   else
+      data->location[1] = location;
+
+   return 1; /* handled */
+}
+
+static int PNGCBAPI
+read_user_chunk_callback(png_struct *png_ptr, png_unknown_chunkp chunk)
+{
+   struct user_chunk_data *my_user_chunk_data =
+      (struct user_chunk_data*)png_get_user_chunk_ptr(png_ptr);
+
+   if (my_user_chunk_data == NULL)
+      png_error(png_ptr, "lost user chunk pointer");
+
+   /* Return one of the following:
+    *    return (-n);  chunk had an error
+    *    return (0);  did not recognize
+    *    return (n);  success
+    *
+    * The unknown chunk structure contains the chunk data:
+    * png_byte name[5];
+    * png_byte *data;
+    * png_size_t size;
+    *
+    * Note that libpng has already taken care of the CRC handling.
+    */
+
+   if (chunk->name[0] == 115 && chunk->name[1] ==  84 &&     /* s  T */
+       chunk->name[2] ==  69 && chunk->name[3] ==  82)       /* E  R */
+      {
+         /* Found sTER chunk */
+         if (chunk->size != 1)
+            return (-1); /* Error return */
+
+         if (chunk->data[0] != 0 && chunk->data[0] != 1)
+            return (-1);  /* Invalid mode */
+
+         if (set_location(png_ptr, my_user_chunk_data, have_sTER) != 0)
+         {
+            my_user_chunk_data->sTER_mode=chunk->data[0];
+            return (1);
+         }
+
+         else
+            return (0); /* duplicate sTER - give it to libpng */
+      }
+
+   if (chunk->name[0] != 118 || chunk->name[1] != 112 ||    /* v  p */
+       chunk->name[2] !=  65 || chunk->name[3] != 103)      /* A  g */
+      return (0); /* Did not recognize */
+
+   /* Found ImageMagick vpAg chunk */
+
+   if (chunk->size != 9)
+      return (-1); /* Error return */
+
+   if (set_location(png_ptr, my_user_chunk_data, have_vpAg) == 0)
+      return (0);  /* duplicate vpAg */
+
+   my_user_chunk_data->vpAg_width = png_get_uint_31(png_ptr, chunk->data);
+   my_user_chunk_data->vpAg_height = png_get_uint_31(png_ptr, chunk->data + 4);
+   my_user_chunk_data->vpAg_units = chunk->data[8];
+
+   return (1);
+}
+
+#ifdef PNG_WRITE_SUPPORTED
+static void
+write_sTER_chunk(png_structp write_ptr)
+{
+   png_byte sTER[5] = {115,  84,  69,  82, '\0'};
+
+   if (verbose != 0)
+      fprintf(STDERR, "\n stereo mode = %d\n", user_chunk_data.sTER_mode);
+
+   png_write_chunk(write_ptr, sTER, &user_chunk_data.sTER_mode, 1);
+}
+
+static void
+write_vpAg_chunk(png_structp write_ptr)
+{
+   png_byte vpAg[5] = {118, 112,  65, 103, '\0'};
+
+   png_byte vpag_chunk_data[9];
+
+   if (verbose != 0)
+      fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n",
+          (unsigned long)user_chunk_data.vpAg_width,
+          (unsigned long)user_chunk_data.vpAg_height,
+          user_chunk_data.vpAg_units);
+
+   png_save_uint_32(vpag_chunk_data, user_chunk_data.vpAg_width);
+   png_save_uint_32(vpag_chunk_data + 4, user_chunk_data.vpAg_height);
+   vpag_chunk_data[8] = user_chunk_data.vpAg_units;
+   png_write_chunk(write_ptr, vpAg, vpag_chunk_data, 9);
+}
+
+static void
+write_chunks(png_structp write_ptr, int location)
+{
+   int i;
+
+   /* Notice that this preserves the original chunk order, however chunks
+    * intercepted by the callback will be written *after* chunks passed to
+    * libpng.  This will actually reverse a pair of sTER chunks or a pair of
+    * vpAg chunks, resulting in an error later.  This is not worth worrying
+    * about - the chunks should not be duplicated!
+    */
+   for (i=0; i<2; ++i)
+   {
+      if (user_chunk_data.location[i] == (location | have_sTER))
+         write_sTER_chunk(write_ptr);
+
+      else if (user_chunk_data.location[i] == (location | have_vpAg))
+         write_vpAg_chunk(write_ptr);
+   }
+}
+#endif /* WRITE */
+#else /* !READ_USER_CHUNKS */
+#  define write_chunks(pp,loc) ((void)0)
+#endif
+/* END of code to demonstrate user chunk support */
+
+/* START of code to check that libpng has the required text support; this only
+ * checks for the write support because if read support is missing the chunk
+ * will simply not be reported back to pngtest.
+ */
+#ifdef PNG_TEXT_SUPPORTED
+static void
+pngtest_check_text_support(png_structp png_ptr, png_textp text_ptr,
+    int num_text)
+{
+   while (num_text > 0)
+   {
+      switch (text_ptr[--num_text].compression)
+      {
+         case PNG_TEXT_COMPRESSION_NONE:
+            break;
+
+         case PNG_TEXT_COMPRESSION_zTXt:
+#           ifndef PNG_WRITE_zTXt_SUPPORTED
+               ++unsupported_chunks;
+               /* In libpng 1.7 this now does an app-error, so stop it: */
+               text_ptr[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+#           endif
+            break;
+
+         case PNG_ITXT_COMPRESSION_NONE:
+         case PNG_ITXT_COMPRESSION_zTXt:
+#           ifndef PNG_WRITE_iTXt_SUPPORTED
+               ++unsupported_chunks;
+               text_ptr[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+#           endif
+            break;
+
+         default:
+            /* This is an error */
+            png_error(png_ptr, "invalid text chunk compression field");
+            break;
+      }
+   }
+}
+#endif
+/* END of code to check that libpng has the required text support */
+
+/* Test one file */
+static int
+test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
+{
+   static png_FILE_p fpin;
+   static png_FILE_p fpout;  /* "static" prevents setjmp corruption */
+   pngtest_error_parameters error_parameters;
+   png_structp read_ptr;
+   png_infop read_info_ptr, end_info_ptr;
+#ifdef PNG_WRITE_SUPPORTED
+   png_structp write_ptr;
+   png_infop write_info_ptr;
+   png_infop write_end_info_ptr;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   int interlace_preserved = 1;
+#endif /* WRITE_FILTER */
+#else /* !WRITE */
+   png_structp write_ptr = NULL;
+   png_infop write_info_ptr = NULL;
+   png_infop write_end_info_ptr = NULL;
+#endif /* !WRITE */
+   png_bytep row_buf;
+   png_uint_32 y;
+   png_uint_32 width, height;
+   volatile int num_passes;
+   int pass;
+   int bit_depth, color_type;
+
+   row_buf = NULL;
+   error_parameters.file_name = inname;
+
+   if ((fpin = fopen(inname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find input file %s\n", inname);
+      return (1);
+   }
+
+   if ((fpout = fopen(outname, "wb")) == NULL)
+   {
+      fprintf(STDERR, "Could not open output file %s\n", outname);
+      FCLOSE(fpin);
+      return (1);
+   }
+
+   pngtest_debug("Allocating read and write structures");
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+   read_ptr =
+       png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+#else
+   read_ptr =
+       png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+#endif
+   png_set_error_fn(read_ptr, &error_parameters, pngtest_error,
+       pngtest_warning);
+
+#ifdef PNG_WRITE_SUPPORTED
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+   write_ptr =
+       png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL,
+       NULL, NULL, NULL, png_debug_malloc, png_debug_free);
+#else
+   write_ptr =
+       png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+#endif
+   png_set_error_fn(write_ptr, &error_parameters, pngtest_error,
+       pngtest_warning);
+#endif
+   pngtest_debug("Allocating read_info, write_info and end_info structures");
+   read_info_ptr = png_create_info_struct(read_ptr);
+   end_info_ptr = png_create_info_struct(read_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+   write_info_ptr = png_create_info_struct(write_ptr);
+   write_end_info_ptr = png_create_info_struct(write_ptr);
+#endif
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   init_callback_info(read_info_ptr);
+   png_set_read_user_chunk_fn(read_ptr, &user_chunk_data,
+       read_user_chunk_callback);
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+   pngtest_debug("Setting jmpbuf for read struct");
+   if (setjmp(png_jmpbuf(read_ptr)))
+   {
+      fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname);
+      png_free(read_ptr, row_buf);
+      row_buf = NULL;
+      if (verbose != 0)
+        fprintf(STDERR, "   destroy read structs\n");
+      png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+      if (verbose != 0)
+        fprintf(STDERR, "   destroy write structs\n");
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+      png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+      FCLOSE(fpin);
+      FCLOSE(fpout);
+      return (1);
+   }
+
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("Setting jmpbuf for write struct");
+
+   if (setjmp(png_jmpbuf(write_ptr)))
+   {
+      fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname);
+      if (verbose != 0)
+        fprintf(STDERR, "   destroying read structs\n");
+      png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+      if (verbose != 0)
+        fprintf(STDERR, "   destroying write structs\n");
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+      png_destroy_write_struct(&write_ptr, &write_info_ptr);
+      FCLOSE(fpin);
+      FCLOSE(fpout);
+      return (1);
+   }
+#endif
+#endif
+
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+   if (strict != 0)
+   {
+      /* Treat png_benign_error() as errors on read */
+      png_set_benign_errors(read_ptr, 0);
+
+# ifdef PNG_WRITE_SUPPORTED
+      /* Treat them as errors on write */
+      png_set_benign_errors(write_ptr, 0);
+# endif
+
+      /* if strict is not set, then app warnings and errors are treated as
+       * warnings in release builds, but not in unstable builds; this can be
+       * changed with '--relaxed'.
+       */
+   }
+
+   else if (relaxed != 0)
+   {
+      /* Allow application (pngtest) errors and warnings to pass */
+      png_set_benign_errors(read_ptr, 1);
+
+      /* Turn off CRC checking while reading */
+      png_set_crc_action(read_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+
+#ifdef PNG_IGNORE_ADLER32
+      /* Turn off ADLER32 checking while reading */
+      png_set_option(read_ptr, PNG_IGNORE_ADLER32, PNG_OPTION_ON);
+#endif
+
+# ifdef PNG_WRITE_SUPPORTED
+      png_set_benign_errors(write_ptr, 1);
+# endif
+
+   }
+#endif /* BENIGN_ERRORS */
+
+   pngtest_debug("Initializing input and output streams");
+#ifdef PNG_STDIO_SUPPORTED
+   png_init_io(read_ptr, fpin);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_init_io(write_ptr, fpout);
+#  endif
+#else
+   png_set_read_fn(read_ptr, (png_voidp)fpin, pngtest_read_data);
+#  ifdef PNG_WRITE_SUPPORTED
+   png_set_write_fn(write_ptr, (png_voidp)fpout,  pngtest_write_data,
+#    ifdef PNG_WRITE_FLUSH_SUPPORTED
+       pngtest_flush);
+#    else
+       NULL);
+#    endif
+#  endif
+#endif
+
+   if (status_dots_requested == 1)
+   {
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_write_status_fn(write_ptr, write_row_callback);
+#endif
+      png_set_read_status_fn(read_ptr, read_row_callback);
+   }
+
+   else
+   {
+#ifdef PNG_WRITE_SUPPORTED
+      png_set_write_status_fn(write_ptr, NULL);
+#endif
+      png_set_read_status_fn(read_ptr, NULL);
+   }
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   png_set_read_user_transform_fn(read_ptr, read_user_callback);
+#endif
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   zero_samples = 0;
+   png_set_write_user_transform_fn(write_ptr, count_zero_samples);
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   /* Preserve all the unknown chunks, if possible.  If this is disabled then,
+    * even if the png_{get,set}_unknown_chunks stuff is enabled, we can't use
+    * libpng to *save* the unknown chunks on read (because we can't switch the
+    * save option on!)
+    *
+    * Notice that if SET_UNKNOWN_CHUNKS is *not* supported read will discard all
+    * unknown chunks and write will write them all.
+    */
+#ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+   png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS,
+       NULL, 0);
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS,
+       NULL, 0);
+#endif
+#endif
+
+   pngtest_debug("Reading info struct");
+   png_read_info(read_ptr, read_info_ptr);
+
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+   /* This is a bit of a hack; there is no obvious way in the callback function
+    * to determine that the chunks before the first IDAT have been read, so
+    * remove the info_ptr (which is only used to determine position relative to
+    * PLTE) here to indicate that we are after the IDAT.
+    */
+   user_chunk_data.info_ptr = NULL;
+#endif
+
+   pngtest_debug("Transferring info struct");
+   {
+      int interlace_type, compression_type, filter_type;
+
+      if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth,
+          &color_type, &interlace_type, &compression_type, &filter_type) != 0)
+      {
+         png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth,
+             color_type, interlace_type, compression_type, filter_type);
+         /* num_passes may not be available below if interlace support is not
+          * provided by libpng for both read and write.
+          */
+         switch (interlace_type)
+         {
+            case PNG_INTERLACE_NONE:
+               num_passes = 1;
+               break;
+
+            case PNG_INTERLACE_ADAM7:
+               num_passes = 7;
+               break;
+
+            default:
+               png_error(read_ptr, "invalid interlace type");
+               /*NOT REACHED*/
+         }
+      }
+
+      else
+         png_error(read_ptr, "png_get_IHDR failed");
+   }
+#ifdef PNG_FIXED_POINT_SUPPORTED
+#ifdef PNG_cHRM_SUPPORTED
+   {
+      png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+          blue_y;
+
+      if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y,
+          &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
+      {
+         png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
+             red_y, green_x, green_y, blue_x, blue_y);
+      }
+   }
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+   {
+      png_fixed_point gamma;
+
+      if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma) != 0)
+         png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma);
+   }
+#endif
+#else /* Use floating point versions */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+#ifdef PNG_cHRM_SUPPORTED
+   {
+      double white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+          blue_y;
+
+      if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
+          &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
+      {
+         png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
+             red_y, green_x, green_y, blue_x, blue_y);
+      }
+   }
+#endif
+#ifdef PNG_gAMA_SUPPORTED
+   {
+      double gamma;
+
+      if (png_get_gAMA(read_ptr, read_info_ptr, &gamma) != 0)
+         png_set_gAMA(write_ptr, write_info_ptr, gamma);
+   }
+#endif
+#endif /* Floating point */
+#endif /* Fixed point */
+#ifdef PNG_iCCP_SUPPORTED
+   {
+      png_charp name;
+      png_bytep profile;
+      png_uint_32 proflen;
+      int compression_type;
+
+      if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
+          &profile, &proflen) != 0)
+      {
+         png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
+             profile, proflen);
+      }
+   }
+#endif
+#ifdef PNG_sRGB_SUPPORTED
+   {
+      int intent;
+
+      if (png_get_sRGB(read_ptr, read_info_ptr, &intent) != 0)
+         png_set_sRGB(write_ptr, write_info_ptr, intent);
+   }
+#endif
+   {
+      png_colorp palette;
+      int num_palette;
+
+      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette) != 0)
+         png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette);
+   }
+#ifdef PNG_bKGD_SUPPORTED
+   {
+      png_color_16p background;
+
+      if (png_get_bKGD(read_ptr, read_info_ptr, &background) != 0)
+      {
+         png_set_bKGD(write_ptr, write_info_ptr, background);
+      }
+   }
+#endif
+#ifdef PNG_READ_eXIf_SUPPORTED
+   {
+      png_bytep exif=NULL;
+      png_uint_32 exif_length;
+
+      if (png_get_eXIf_1(read_ptr, read_info_ptr, &exif_length, &exif) != 0)
+      {
+         if (exif_length > 1)
+            fprintf(STDERR," eXIf type %c%c, %lu bytes\n",exif[0],exif[1],
+               (unsigned long)exif_length);
+# ifdef PNG_WRITE_eXIf_SUPPORTED
+         png_set_eXIf_1(write_ptr, write_info_ptr, exif_length, exif);
+# endif
+      }
+   }
+#endif
+#ifdef PNG_hIST_SUPPORTED
+   {
+      png_uint_16p hist;
+
+      if (png_get_hIST(read_ptr, read_info_ptr, &hist) != 0)
+         png_set_hIST(write_ptr, write_info_ptr, hist);
+   }
+#endif
+#ifdef PNG_oFFs_SUPPORTED
+   {
+      png_int_32 offset_x, offset_y;
+      int unit_type;
+
+      if (png_get_oFFs(read_ptr, read_info_ptr, &offset_x, &offset_y,
+          &unit_type) != 0)
+      {
+         png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type);
+      }
+   }
+#endif
+#ifdef PNG_pCAL_SUPPORTED
+   {
+      png_charp purpose, units;
+      png_charpp params;
+      png_int_32 X0, X1;
+      int type, nparams;
+
+      if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type,
+          &nparams, &units, &params) != 0)
+      {
+         png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type,
+             nparams, units, params);
+      }
+   }
+#endif
+#ifdef PNG_pHYs_SUPPORTED
+   {
+      png_uint_32 res_x, res_y;
+      int unit_type;
+
+      if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y,
+          &unit_type) != 0)
+         png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type);
+   }
+#endif
+#ifdef PNG_sBIT_SUPPORTED
+   {
+      png_color_8p sig_bit;
+
+      if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit) != 0)
+         png_set_sBIT(write_ptr, write_info_ptr, sig_bit);
+   }
+#endif
+#ifdef PNG_sCAL_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
+   {
+      int unit;
+      double scal_width, scal_height;
+
+      if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width,
+          &scal_height) != 0)
+      {
+         png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height);
+      }
+   }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   {
+      int unit;
+      png_charp scal_width, scal_height;
+
+      if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width,
+           &scal_height) != 0)
+      {
+         png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width,
+             scal_height);
+      }
+   }
+#endif
+#endif
+#endif
+
+#ifdef PNG_sPLT_SUPPORTED
+   {
+       png_sPLT_tp entries;
+
+       int num_entries = (int) png_get_sPLT(read_ptr, read_info_ptr, &entries);
+       if (num_entries)
+       {
+           png_set_sPLT(write_ptr, write_info_ptr, entries, num_entries);
+       }
+   }
+#endif
+
+#ifdef PNG_TEXT_SUPPORTED
+   {
+      png_textp text_ptr;
+      int num_text;
+
+      if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
+
+         pngtest_check_text_support(read_ptr, text_ptr, num_text);
+
+         if (verbose != 0)
+         {
+            int i;
+
+            fprintf(STDERR,"\n");
+            for (i=0; i<num_text; i++)
+            {
+               fprintf(STDERR,"   Text compression[%d]=%d\n",
+                   i, text_ptr[i].compression);
+            }
+         }
+
+         png_set_text(write_ptr, write_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#ifdef PNG_tIME_SUPPORTED
+   {
+      png_timep mod_time;
+
+      if (png_get_tIME(read_ptr, read_info_ptr, &mod_time) != 0)
+      {
+         png_set_tIME(write_ptr, write_info_ptr, mod_time);
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time) != 0)
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+
+         else
+         {
+            strncpy(tIME_string, "*** invalid time ***", (sizeof tIME_string));
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+         }
+
+         tIME_chunk_present++;
+#endif /* TIME_RFC1123 */
+      }
+   }
+#endif
+#ifdef PNG_tRNS_SUPPORTED
+   {
+      png_bytep trans_alpha;
+      int num_trans;
+      png_color_16p trans_color;
+
+      if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
+          &trans_color) != 0)
+      {
+         int sample_max = (1 << bit_depth);
+         /* libpng doesn't reject a tRNS chunk with out-of-range samples */
+         if (!((color_type == PNG_COLOR_TYPE_GRAY &&
+             (int)trans_color->gray > sample_max) ||
+             (color_type == PNG_COLOR_TYPE_RGB &&
+             ((int)trans_color->red > sample_max ||
+             (int)trans_color->green > sample_max ||
+             (int)trans_color->blue > sample_max))))
+            png_set_tRNS(write_ptr, write_info_ptr, trans_alpha, num_trans,
+               trans_color);
+      }
+   }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr,
+          &unknowns);
+
+      if (num_unknowns != 0)
+      {
+         png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
+             num_unknowns);
+#if PNG_LIBPNG_VER < 10600
+         /* Copy the locations from the read_info_ptr.  The automatically
+          * generated locations in write_end_info_ptr are wrong prior to 1.6.0
+          * because they are reset from the write pointer (removed in 1.6.0).
+          */
+         {
+            int i;
+            for (i = 0; i < num_unknowns; i++)
+              png_set_unknown_chunk_location(write_ptr, write_info_ptr, i,
+                  unknowns[i].location);
+         }
+#endif
+      }
+   }
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("Writing info struct");
+
+   /* Write the info in two steps so that if we write the 'unknown' chunks here
+    * they go to the correct place.
+    */
+   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+
+   write_chunks(write_ptr, before_PLTE); /* before PLTE */
+
+   png_write_info(write_ptr, write_info_ptr);
+
+   write_chunks(write_ptr, before_IDAT); /* after PLTE */
+
+   png_write_info(write_ptr, write_end_info_ptr);
+
+   write_chunks(write_ptr, after_IDAT); /* after IDAT */
+
+#ifdef PNG_COMPRESSION_COMPAT
+   /* Test the 'compatibility' setting here, if it is available. */
+   png_set_compression(write_ptr, PNG_COMPRESSION_COMPAT);
+#endif
+#endif
+
+#ifdef SINGLE_ROWBUF_ALLOC
+   pngtest_debug("Allocating row buffer...");
+   row_buf = (png_bytep)png_malloc(read_ptr,
+       png_get_rowbytes(read_ptr, read_info_ptr));
+
+   pngtest_debug1("\t0x%08lx", (unsigned long)row_buf);
+#endif /* SINGLE_ROWBUF_ALLOC */
+   pngtest_debug("Writing row data");
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) &&\
+   defined(PNG_WRITE_INTERLACING_SUPPORTED)
+   /* Both must be defined for libpng to be able to handle the interlace,
+    * otherwise it gets handled below by simply reading and writing the passes
+    * directly.
+    */
+   if (png_set_interlace_handling(read_ptr) != num_passes)
+      png_error(write_ptr,
+          "png_set_interlace_handling(read): wrong pass count ");
+   if (png_set_interlace_handling(write_ptr) != num_passes)
+      png_error(write_ptr,
+          "png_set_interlace_handling(write): wrong pass count ");
+#else /* png_set_interlace_handling not called on either read or write */
+#  define calc_pass_height
+#endif /* not using libpng interlace handling */
+
+#ifdef PNGTEST_TIMING
+   t_stop = (float)clock();
+   t_misc += (t_stop - t_start);
+   t_start = t_stop;
+#endif
+   for (pass = 0; pass < num_passes; pass++)
+   {
+#     ifdef calc_pass_height
+         png_uint_32 pass_height;
+
+         if (num_passes == 7) /* interlaced */
+         {
+            if (PNG_PASS_COLS(width, pass) > 0)
+               pass_height = PNG_PASS_ROWS(height, pass);
+
+            else
+               pass_height = 0;
+         }
+
+         else /* not interlaced */
+            pass_height = height;
+#     else
+#        define pass_height height
+#     endif
+
+      pngtest_debug1("Writing row data for pass %d", pass);
+      for (y = 0; y < pass_height; y++)
+      {
+#ifndef SINGLE_ROWBUF_ALLOC
+         pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
+
+         row_buf = (png_bytep)png_malloc(read_ptr,
+             png_get_rowbytes(read_ptr, read_info_ptr));
+
+         pngtest_debug2("\t0x%08lx (%lu bytes)", (unsigned long)row_buf,
+             (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
+
+#endif /* !SINGLE_ROWBUF_ALLOC */
+         png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNGTEST_TIMING
+         t_stop = (float)clock();
+         t_decode += (t_stop - t_start);
+         t_start = t_stop;
+#endif
+         png_write_rows(write_ptr, (png_bytepp)&row_buf, 1);
+#ifdef PNGTEST_TIMING
+         t_stop = (float)clock();
+         t_encode += (t_stop - t_start);
+         t_start = t_stop;
+#endif
+#endif /* WRITE */
+
+#ifndef SINGLE_ROWBUF_ALLOC
+         pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y);
+         png_free(read_ptr, row_buf);
+         row_buf = NULL;
+#endif /* !SINGLE_ROWBUF_ALLOC */
+      }
+   }
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
+#  ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
+#endif
+
+   pngtest_debug("Reading and writing end_info data");
+
+   png_read_end(read_ptr, end_info_ptr);
+#ifdef PNG_TEXT_SUPPORTED
+   {
+      png_textp text_ptr;
+      int num_text;
+
+      if (png_get_text(read_ptr, end_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text);
+
+         pngtest_check_text_support(read_ptr, text_ptr, num_text);
+
+         if (verbose != 0)
+         {
+            int i;
+
+            fprintf(STDERR,"\n");
+            for (i=0; i<num_text; i++)
+            {
+               fprintf(STDERR,"   Text compression[%d]=%d\n",
+                   i, text_ptr[i].compression);
+            }
+         }
+
+         png_set_text(write_ptr, write_end_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#ifdef PNG_READ_eXIf_SUPPORTED
+   {
+      png_bytep exif=NULL;
+      png_uint_32 exif_length;
+
+      if (png_get_eXIf_1(read_ptr, end_info_ptr, &exif_length, &exif) != 0)
+      {
+         if (exif_length > 1)
+            fprintf(STDERR," eXIf type %c%c, %lu bytes\n",exif[0],exif[1],
+               (unsigned long)exif_length);
+# ifdef PNG_WRITE_eXIf_SUPPORTED
+         png_set_eXIf_1(write_ptr, write_end_info_ptr, exif_length, exif);
+# endif
+      }
+   }
+#endif
+#ifdef PNG_tIME_SUPPORTED
+   {
+      png_timep mod_time;
+
+      if (png_get_tIME(read_ptr, end_info_ptr, &mod_time) != 0)
+      {
+         png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time) != 0)
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+
+         else
+         {
+            strncpy(tIME_string, "*** invalid time ***", sizeof tIME_string);
+            tIME_string[(sizeof tIME_string)-1] = '\0';
+         }
+
+         tIME_chunk_present++;
+#endif /* TIME_RFC1123 */
+      }
+   }
+#endif
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr,
+          &unknowns);
+
+      if (num_unknowns != 0)
+      {
+         png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
+             num_unknowns);
+#if PNG_LIBPNG_VER < 10600
+         /* Copy the locations from the read_info_ptr.  The automatically
+          * generated locations in write_end_info_ptr are wrong prior to 1.6.0
+          * because they are reset from the write pointer (removed in 1.6.0).
+          */
+         {
+            int i;
+            for (i = 0; i < num_unknowns; i++)
+              png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i,
+                  unknowns[i].location);
+         }
+#endif
+      }
+   }
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
+    * This is here just to make pngtest replicate the results from libpng
+    * versions prior to 1.5.4, and to test this new API.
+    */
+   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
+#endif
+
+   /* When the unknown vpAg/sTER chunks are written by pngtest the only way to
+    * do it is to write them *before* calling png_write_end.  When unknown
+    * chunks are written by libpng, however, they are written just before IEND.
+    * There seems to be no way round this, however vpAg/sTER are not expected
+    * after IDAT.
+    */
+   write_chunks(write_ptr, after_IDAT);
+
+   png_write_end(write_ptr, write_end_info_ptr);
+#endif
+
+#ifdef PNG_EASY_ACCESS_SUPPORTED
+   if (verbose != 0)
+   {
+      png_uint_32 iwidth, iheight;
+      iwidth = png_get_image_width(write_ptr, write_info_ptr);
+      iheight = png_get_image_height(write_ptr, write_info_ptr);
+      fprintf(STDERR, "\n Image width = %lu, height = %lu\n",
+          (unsigned long)iwidth, (unsigned long)iheight);
+   }
+#endif
+
+   pngtest_debug("Destroying data structs");
+#ifdef SINGLE_ROWBUF_ALLOC
+   pngtest_debug("destroying row_buf for read_ptr");
+   png_free(read_ptr, row_buf);
+   row_buf = NULL;
+#endif /* SINGLE_ROWBUF_ALLOC */
+   pngtest_debug("destroying read_ptr, read_info_ptr, end_info_ptr");
+   png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+#ifdef PNG_WRITE_SUPPORTED
+   pngtest_debug("destroying write_end_info_ptr");
+   png_destroy_info_struct(write_ptr, &write_end_info_ptr);
+   pngtest_debug("destroying write_ptr, write_info_ptr");
+   png_destroy_write_struct(&write_ptr, &write_info_ptr);
+#endif
+   pngtest_debug("Destruction complete.");
+
+   FCLOSE(fpin);
+   FCLOSE(fpout);
+
+   /* Summarize any warnings or errors and in 'strict' mode fail the test.
+    * Unsupported chunks can result in warnings, in that case ignore the strict
+    * setting, otherwise fail the test on warnings as well as errors.
+    */
+   if (error_count > 0)
+   {
+      /* We don't really expect to get here because of the setjmp handling
+       * above, but this is safe.
+       */
+      fprintf(STDERR, "\n  %s: %d libpng errors found (%d warnings)",
+          inname, error_count, warning_count);
+
+      if (strict != 0)
+         return (1);
+   }
+
+#  ifdef PNG_WRITE_SUPPORTED
+      /* If there is no write support nothing was written! */
+      else if (unsupported_chunks > 0)
+      {
+         fprintf(STDERR, "\n  %s: unsupported chunks (%d)%s",
+             inname, unsupported_chunks, strict ? ": IGNORED --strict!" : "");
+      }
+#  endif
+
+   else if (warning_count > 0)
+   {
+      fprintf(STDERR, "\n  %s: %d libpng warnings found",
+          inname, warning_count);
+
+      if (strict != 0)
+         return (1);
+   }
+
+   pngtest_debug("Opening files for comparison");
+   if ((fpin = fopen(inname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find file %s\n", inname);
+      return (1);
+   }
+
+   if ((fpout = fopen(outname, "rb")) == NULL)
+   {
+      fprintf(STDERR, "Could not find file %s\n", outname);
+      FCLOSE(fpin);
+      return (1);
+   }
+
+#if defined (PNG_WRITE_SUPPORTED) /* else nothing was written */ &&\
+    defined (PNG_WRITE_FILTER_SUPPORTED)
+   if (interlace_preserved != 0) /* else the files will be changed */
+   {
+      for (;;)
+      {
+         static int wrote_question = 0;
+         png_size_t num_in, num_out;
+         char inbuf[256], outbuf[256];
+
+         num_in = fread(inbuf, 1, sizeof inbuf, fpin);
+         num_out = fread(outbuf, 1, sizeof outbuf, fpout);
+
+         if (num_in != num_out)
+         {
+            fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
+                inname, outname);
+
+            if (wrote_question == 0 && unsupported_chunks == 0)
+            {
+               fprintf(STDERR,
+                   "   Was %s written with the same maximum IDAT"
+                   " chunk size (%d bytes),",
+                   inname, PNG_ZBUF_SIZE);
+               fprintf(STDERR,
+                   "\n   filtering heuristic (libpng default), compression");
+               fprintf(STDERR,
+                   " level (zlib default),\n   and zlib version (%s)?\n\n",
+                   ZLIB_VERSION);
+               wrote_question = 1;
+            }
+
+            FCLOSE(fpin);
+            FCLOSE(fpout);
+
+            if (strict != 0 && unsupported_chunks == 0)
+              return (1);
+
+            else
+              return (0);
+         }
+
+         if (num_in == 0)
+            break;
+
+         if (memcmp(inbuf, outbuf, num_in))
+         {
+            fprintf(STDERR, "\nFiles %s and %s are different\n", inname,
+                outname);
+
+            if (wrote_question == 0 && unsupported_chunks == 0)
+            {
+               fprintf(STDERR,
+                   "   Was %s written with the same maximum"
+                   " IDAT chunk size (%d bytes),",
+                    inname, PNG_ZBUF_SIZE);
+               fprintf(STDERR,
+                   "\n   filtering heuristic (libpng default), compression");
+               fprintf(STDERR,
+                   " level (zlib default),\n   and zlib version (%s)?\n\n",
+                 ZLIB_VERSION);
+               wrote_question = 1;
+            }
+
+            FCLOSE(fpin);
+            FCLOSE(fpout);
+
+            /* NOTE: the unsupported_chunks escape is permitted here because
+             * unsupported text chunk compression will result in the compression
+             * mode being changed (to NONE) yet, in the test case, the result
+             * can be exactly the same size!
+             */
+            if (strict != 0 && unsupported_chunks == 0)
+              return (1);
+
+            else
+              return (0);
+         }
+      }
+   }
+#endif /* WRITE && WRITE_FILTER */
+
+   FCLOSE(fpin);
+   FCLOSE(fpout);
+
+   return (0);
+}
+
+/* Input and output filenames */
+#ifdef RISCOS
+static PNG_CONST char *inname = "pngtest/png";
+static PNG_CONST char *outname = "pngout/png";
+#else
+static PNG_CONST char *inname = "pngtest.png";
+static PNG_CONST char *outname = "pngout.png";
+#endif
+
+int
+main(int argc, char *argv[])
+{
+   int multiple = 0;
+   int ierror = 0;
+
+   png_structp dummy_ptr;
+
+   fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
+   fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
+   fprintf(STDERR, "%s", png_get_copyright(NULL));
+   /* Show the version of libpng used in building the library */
+   fprintf(STDERR, " library (%lu):%s",
+       (unsigned long)png_access_version_number(),
+       png_get_header_version(NULL));
+
+   /* Show the version of libpng used in building the application */
+   fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER,
+       PNG_HEADER_VERSION_STRING);
+
+   /* Do some consistency checking on the memory allocation settings, I'm
+    * not sure this matters, but it is nice to know, the first of these
+    * tests should be impossible because of the way the macros are set
+    * in pngconf.h
+    */
+#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K)
+      fprintf(STDERR, " NOTE: Zlib compiled for max 64k, libpng not\n");
+#endif
+   /* I think the following can happen. */
+#if !defined(MAXSEG_64K) && defined(PNG_MAX_MALLOC_64K)
+      fprintf(STDERR, " NOTE: libpng compiled for max 64k, zlib not\n");
+#endif
+
+   if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING))
+   {
+      fprintf(STDERR,
+          "Warning: versions are different between png.h and png.c\n");
+      fprintf(STDERR, "  png.h version: %s\n", PNG_LIBPNG_VER_STRING);
+      fprintf(STDERR, "  png.c version: %s\n\n", png_libpng_ver);
+      ++ierror;
+   }
+
+   if (argc > 1)
+   {
+      if (strcmp(argv[1], "-m") == 0)
+      {
+         multiple = 1;
+         status_dots_requested = 0;
+      }
+
+      else if (strcmp(argv[1], "-mv") == 0 ||
+               strcmp(argv[1], "-vm") == 0 )
+      {
+         multiple = 1;
+         verbose = 1;
+         status_dots_requested = 1;
+      }
+
+      else if (strcmp(argv[1], "-v") == 0)
+      {
+         verbose = 1;
+         status_dots_requested = 1;
+         inname = argv[2];
+      }
+
+      else if (strcmp(argv[1], "--strict") == 0)
+      {
+         status_dots_requested = 0;
+         verbose = 1;
+         inname = argv[2];
+         strict++;
+         relaxed = 0;
+         multiple=1;
+      }
+
+      else if (strcmp(argv[1], "--relaxed") == 0)
+      {
+         status_dots_requested = 0;
+         verbose = 1;
+         inname = argv[2];
+         strict = 0;
+         relaxed++;
+         multiple=1;
+      }
+      else if (strcmp(argv[1], "--xfail") == 0)
+      {
+         status_dots_requested = 0;
+         verbose = 1;
+         inname = argv[2];
+         strict = 0;
+         xfail++;
+         relaxed++;
+         multiple=1;
+      }
+
+      else
+      {
+         inname = argv[1];
+         status_dots_requested = 0;
+      }
+   }
+
+   if (multiple == 0 && argc == 3 + verbose)
+      outname = argv[2 + verbose];
+
+   if ((multiple == 0 && argc > 3 + verbose) ||
+       (multiple != 0 && argc < 2))
+   {
+      fprintf(STDERR,
+          "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
+          argv[0], argv[0]);
+      fprintf(STDERR,
+          "  reads/writes one PNG file (without -m) or multiple files (-m)\n");
+      fprintf(STDERR,
+          "  with -m %s is used as a temporary file\n", outname);
+      exit(1);
+   }
+
+   if (multiple != 0)
+   {
+      int i;
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+      int allocation_now = current_allocation;
+#endif
+      for (i=2; i<argc; ++i)
+      {
+         int kerror;
+         fprintf(STDERR, "\n Testing %s:", argv[i]);
+#if PNG_DEBUG > 0
+         fprintf(STDERR, "\n");
+#endif
+         kerror = test_one_file(argv[i], outname);
+         if (kerror == 0)
+         {
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+            fprintf(STDERR, "\n PASS (%lu zero samples)\n",
+                (unsigned long)zero_samples);
+#else
+            fprintf(STDERR, " PASS\n");
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+            if (tIME_chunk_present != 0)
+               fprintf(STDERR, " tIME = %s\n", tIME_string);
+
+            tIME_chunk_present = 0;
+#endif /* TIME_RFC1123 */
+         }
+
+         else
+         {
+            if (xfail)
+              fprintf(STDERR, " XFAIL\n");
+            else
+            {
+              fprintf(STDERR, " FAIL\n");
+              ierror += kerror;
+            }
+         }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         if (allocation_now != current_allocation)
+            fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
+                current_allocation - allocation_now);
+
+         if (current_allocation != 0)
+         {
+            memory_infop pinfo = pinformation;
+
+            fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
+                current_allocation);
+
+            while (pinfo != NULL)
+            {
+               fprintf(STDERR, " %lu bytes at %p\n",
+                   (unsigned long)pinfo->size,
+                   pinfo->pointer);
+               pinfo = pinfo->next;
+            }
+         }
+#endif
+      }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         fprintf(STDERR, " Current memory allocation: %10d bytes\n",
+             current_allocation);
+         fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
+             maximum_allocation);
+         fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
+             total_allocation);
+         fprintf(STDERR, "     Number of allocations: %10d\n",
+             num_allocations);
+#endif
+   }
+
+   else
+   {
+      int i;
+      for (i = 0; i<3; ++i)
+      {
+         int kerror;
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         int allocation_now = current_allocation;
+#endif
+         if (i == 1)
+            status_dots_requested = 1;
+
+         else if (verbose == 0)
+            status_dots_requested = 0;
+
+         if (i == 0 || verbose == 1 || ierror != 0)
+         {
+            fprintf(STDERR, "\n Testing %s:", inname);
+#if PNG_DEBUG > 0
+            fprintf(STDERR, "\n");
+#endif
+         }
+
+         kerror = test_one_file(inname, outname);
+
+         if (kerror == 0)
+         {
+            if (verbose == 1 || i == 2)
+            {
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+                fprintf(STDERR, "\n PASS (%lu zero samples)\n",
+                    (unsigned long)zero_samples);
+#else
+                fprintf(STDERR, " PASS\n");
+#endif
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+             if (tIME_chunk_present != 0)
+                fprintf(STDERR, " tIME = %s\n", tIME_string);
+#endif /* TIME_RFC1123 */
+            }
+         }
+
+         else
+         {
+            if (verbose == 0 && i != 2)
+            {
+               fprintf(STDERR, "\n Testing %s:", inname);
+#if PNG_DEBUG > 0
+               fprintf(STDERR, "\n");
+#endif
+            }
+
+            if (xfail)
+              fprintf(STDERR, " XFAIL\n");
+            else
+            {
+              fprintf(STDERR, " FAIL\n");
+              ierror += kerror;
+            }
+         }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+         if (allocation_now != current_allocation)
+             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
+                 current_allocation - allocation_now);
+
+         if (current_allocation != 0)
+         {
+             memory_infop pinfo = pinformation;
+
+             fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
+                 current_allocation);
+
+             while (pinfo != NULL)
+             {
+                fprintf(STDERR, " %lu bytes at %p\n",
+                    (unsigned long)pinfo->size, pinfo->pointer);
+                pinfo = pinfo->next;
+             }
+          }
+#endif
+       }
+#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
+       fprintf(STDERR, " Current memory allocation: %10d bytes\n",
+           current_allocation);
+       fprintf(STDERR, " Maximum memory allocation: %10d bytes\n",
+           maximum_allocation);
+       fprintf(STDERR, " Total   memory allocation: %10d bytes\n",
+           total_allocation);
+       fprintf(STDERR, "     Number of allocations: %10d\n",
+           num_allocations);
+#endif
+   }
+
+#ifdef PNGTEST_TIMING
+   t_stop = (float)clock();
+   t_misc += (t_stop - t_start);
+   t_start = t_stop;
+   fprintf(STDERR, " CPU time used = %.3f seconds",
+       (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, " (decoding %.3f,\n",
+       t_decode/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, "        encoding %.3f ,",
+       t_encode/(float)CLOCKS_PER_SEC);
+   fprintf(STDERR, " other %.3f seconds)\n\n",
+       t_misc/(float)CLOCKS_PER_SEC);
+#endif
+
+   if (ierror == 0)
+      fprintf(STDERR, " libpng passes test\n");
+
+   else
+      fprintf(STDERR, " libpng FAILS test\n");
+
+   dummy_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+   fprintf(STDERR, " Default limits:\n");
+   fprintf(STDERR, "  width_max  = %lu\n",
+       (unsigned long) png_get_user_width_max(dummy_ptr));
+   fprintf(STDERR, "  height_max = %lu\n",
+       (unsigned long) png_get_user_height_max(dummy_ptr));
+   if (png_get_chunk_cache_max(dummy_ptr) == 0)
+      fprintf(STDERR, "  cache_max  = unlimited\n");
+   else
+      fprintf(STDERR, "  cache_max  = %lu\n",
+          (unsigned long) png_get_chunk_cache_max(dummy_ptr));
+   if (png_get_chunk_malloc_max(dummy_ptr) == 0)
+      fprintf(STDERR, "  malloc_max = unlimited\n");
+   else
+      fprintf(STDERR, "  malloc_max = %lu\n",
+          (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
+   png_destroy_read_struct(&dummy_ptr, NULL, NULL);
+
+   return (int)(ierror != 0);
+}
+#else
+int
+main(void)
+{
+   fprintf(STDERR,
+       " test ignored because libpng was not built with read support\n");
+   /* And skip this test */
+   return PNG_LIBPNG_VER < 10600 ? 0 : 77;
+}
+#endif
+
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef png_libpng_version_1_6_34 Your_png_h_is_not_version_1_6_34;
diff --git a/xs/src/png/libpng/pngtrans.c b/xs/src/png/libpng/pngtrans.c
new file mode 100644
index 000000000..6882f0fd7
--- /dev/null
+++ b/xs/src/png/libpng/pngtrans.c
@@ -0,0 +1,864 @@
+
+/* pngtrans.c - transforms the data in a row (used by both readers and writers)
+ *
+ * Last changed in libpng 1.6.33 [September 28, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Turn on BGR-to-RGB mapping */
+void PNGAPI
+png_set_bgr(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_bgr");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_BGR;
+}
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Turn on 16-bit byte swapping */
+void PNGAPI
+png_set_swap(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_swap");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (png_ptr->bit_depth == 16)
+      png_ptr->transformations |= PNG_SWAP_BYTES;
+}
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+/* Turn on pixel packing */
+void PNGAPI
+png_set_packing(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_packing");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (png_ptr->bit_depth < 8)
+   {
+      png_ptr->transformations |= PNG_PACK;
+#     ifdef PNG_WRITE_SUPPORTED
+         png_ptr->usr_bit_depth = 8;
+#     endif
+   }
+}
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+/* Turn on packed pixel swapping */
+void PNGAPI
+png_set_packswap(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_packswap");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (png_ptr->bit_depth < 8)
+      png_ptr->transformations |= PNG_PACKSWAP;
+}
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
+void PNGAPI
+png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
+{
+   png_debug(1, "in png_set_shift");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_SHIFT;
+   png_ptr->shift = *true_bits;
+}
+#endif
+
+#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
+    defined(PNG_WRITE_INTERLACING_SUPPORTED)
+int PNGAPI
+png_set_interlace_handling(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_interlace handling");
+
+   if (png_ptr != 0 && png_ptr->interlaced != 0)
+   {
+      png_ptr->transformations |= PNG_INTERLACE;
+      return (7);
+   }
+
+   return (1);
+}
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
+/* Add a filler byte on read, or remove a filler or alpha byte on write.
+ * The filler type has changed in v0.95 to allow future 2-byte fillers
+ * for 48-bit input data, as well as to avoid problems with some compilers
+ * that don't like bytes as parameters.
+ */
+void PNGAPI
+png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_filler");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* In libpng 1.6 it is possible to determine whether this is a read or write
+    * operation and therefore to do more checking here for a valid call.
+    */
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+   {
+#     ifdef PNG_READ_FILLER_SUPPORTED
+         /* On read png_set_filler is always valid, regardless of the base PNG
+          * format, because other transformations can give a format where the
+          * filler code can execute (basically an 8 or 16-bit component RGB or G
+          * format.)
+          *
+          * NOTE: usr_channels is not used by the read code!  (This has led to
+          * confusion in the past.)  The filler is only used in the read code.
+          */
+         png_ptr->filler = (png_uint_16)filler;
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on read");
+         PNG_UNUSED(filler) /* not used in the write case */
+         return;
+#     endif
+   }
+
+   else /* write */
+   {
+#     ifdef PNG_WRITE_FILLER_SUPPORTED
+         /* On write the usr_channels parameter must be set correctly at the
+          * start to record the number of channels in the app-supplied data.
+          */
+         switch (png_ptr->color_type)
+         {
+            case PNG_COLOR_TYPE_RGB:
+               png_ptr->usr_channels = 4;
+               break;
+
+            case PNG_COLOR_TYPE_GRAY:
+               if (png_ptr->bit_depth >= 8)
+               {
+                  png_ptr->usr_channels = 2;
+                  break;
+               }
+
+               else
+               {
+                  /* There simply isn't any code in libpng to strip out bits
+                   * from bytes when the components are less than a byte in
+                   * size!
+                   */
+                  png_app_error(png_ptr,
+                      "png_set_filler is invalid for"
+                      " low bit depth gray output");
+                  return;
+               }
+
+            default:
+               png_app_error(png_ptr,
+                   "png_set_filler: inappropriate color type");
+               return;
+         }
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on write");
+         return;
+#     endif
+   }
+
+   /* Here on success - libpng supports the operation, set the transformation
+    * and the flag to say where the filler channel is.
+    */
+   png_ptr->transformations |= PNG_FILLER;
+
+   if (filler_loc == PNG_FILLER_AFTER)
+      png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
+
+   else
+      png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+}
+
+/* Added to libpng-1.2.7 */
+void PNGAPI
+png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
+{
+   png_debug(1, "in png_set_add_alpha");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_set_filler(png_ptr, filler, filler_loc);
+   /* The above may fail to do anything. */
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_ptr->transformations |= PNG_ADD_ALPHA;
+}
+
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_swap_alpha(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_swap_alpha");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_SWAP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
+    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_invert_alpha(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_invert_alpha");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_INVERT_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
+void PNGAPI
+png_set_invert_mono(png_structrp png_ptr)
+{
+   png_debug(1, "in png_set_invert_mono");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_INVERT_MONO;
+}
+
+/* Invert monochrome grayscale data */
+void /* PRIVATE */
+png_do_invert(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_invert");
+
+  /* This test removed from libpng version 1.0.13 and 1.2.0:
+   *   if (row_info->bit_depth == 1 &&
+   */
+   if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+
+      for (i = 0; i < istop; i++)
+      {
+         *rp = (png_byte)(~(*rp));
+         rp++;
+      }
+   }
+
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+      row_info->bit_depth == 8)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+
+      for (i = 0; i < istop; i += 2)
+      {
+         *rp = (png_byte)(~(*rp));
+         rp += 2;
+      }
+   }
+
+#ifdef PNG_16BIT_SUPPORTED
+   else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
+      row_info->bit_depth == 16)
+   {
+      png_bytep rp = row;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;
+
+      for (i = 0; i < istop; i += 4)
+      {
+         *rp = (png_byte)(~(*rp));
+         *(rp + 1) = (png_byte)(~(*(rp + 1)));
+         rp += 4;
+      }
+   }
+#endif
+}
+#endif
+
+#ifdef PNG_16BIT_SUPPORTED
+#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
+/* Swaps byte order on 16-bit depth images */
+void /* PRIVATE */
+png_do_swap(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_swap");
+
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep rp = row;
+      png_uint_32 i;
+      png_uint_32 istop= row_info->width * row_info->channels;
+
+      for (i = 0; i < istop; i++, rp += 2)
+      {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+         /* Feature added to libpng-1.6.11 for testing purposes, not
+          * enabled by default.
+          */
+         *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
+         png_byte t = *rp;
+         *rp = *(rp + 1);
+         *(rp + 1) = t;
+#endif
+      }
+   }
+}
+#endif
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+static PNG_CONST png_byte onebppswaptable[256] = {
+   0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
+   0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
+   0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
+   0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
+   0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
+   0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
+   0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
+   0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
+   0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
+   0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
+   0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
+   0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
+   0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
+   0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
+   0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
+   0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
+   0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
+   0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
+   0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
+   0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
+   0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
+   0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
+   0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
+   0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
+   0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
+   0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
+   0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
+   0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
+   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
+   0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
+   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
+   0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
+};
+
+static PNG_CONST png_byte twobppswaptable[256] = {
+   0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0,
+   0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0,
+   0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4,
+   0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4,
+   0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8,
+   0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8,
+   0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC,
+   0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC,
+   0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1,
+   0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1,
+   0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5,
+   0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5,
+   0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9,
+   0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9,
+   0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD,
+   0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD,
+   0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2,
+   0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2,
+   0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6,
+   0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6,
+   0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA,
+   0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA,
+   0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE,
+   0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE,
+   0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3,
+   0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3,
+   0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7,
+   0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7,
+   0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB,
+   0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB,
+   0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF,
+   0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF
+};
+
+static PNG_CONST png_byte fourbppswaptable[256] = {
+   0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
+   0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0,
+   0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71,
+   0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1,
+   0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72,
+   0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2,
+   0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73,
+   0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3,
+   0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74,
+   0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4,
+   0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75,
+   0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5,
+   0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76,
+   0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6,
+   0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77,
+   0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7,
+   0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78,
+   0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8,
+   0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79,
+   0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9,
+   0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A,
+   0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA,
+   0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B,
+   0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB,
+   0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C,
+   0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC,
+   0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D,
+   0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD,
+   0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E,
+   0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE,
+   0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F,
+   0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF
+};
+
+/* Swaps pixel packing order within bytes */
+void /* PRIVATE */
+png_do_packswap(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_packswap");
+
+   if (row_info->bit_depth < 8)
+   {
+      png_bytep rp;
+      png_const_bytep end, table;
+
+      end = row + row_info->rowbytes;
+
+      if (row_info->bit_depth == 1)
+         table = onebppswaptable;
+
+      else if (row_info->bit_depth == 2)
+         table = twobppswaptable;
+
+      else if (row_info->bit_depth == 4)
+         table = fourbppswaptable;
+
+      else
+         return;
+
+      for (rp = row; rp < end; rp++)
+         *rp = table[*rp];
+   }
+}
+#endif /* PACKSWAP || WRITE_PACKSWAP */
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
+    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do.  All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */
+void /* PRIVATE */
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
+{
+   png_bytep sp = row; /* source pointer */
+   png_bytep dp = row; /* destination pointer */
+   png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+   /* At the start sp will point to the first byte to copy and dp to where
+    * it is copied to.  ep always points just beyond the end of the row, so
+    * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+    */
+
+   /* GA, GX, XG cases */
+   if (row_info->channels == 2)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channel and, for sp, the filler */
+         {
+            sp += 2; ++dp;
+         }
+
+         /* For a 1 pixel wide image there is nothing to do */
+         while (sp < ep)
+         {
+            *dp++ = *sp; sp += 2;
+         }
+
+         row_info->pixel_depth = 8;
+      }
+
+      else if (row_info->bit_depth == 16)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channel and, for sp, the filler */
+         {
+            sp += 4; dp += 2;
+         }
+
+         while (sp < ep)
+         {
+            *dp++ = *sp++; *dp++ = *sp; sp += 3;
+         }
+
+         row_info->pixel_depth = 16;
+      }
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 1;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_GRAY;
+   }
+
+   /* RGBA, RGBX, XRGB cases */
+   else if (row_info->channels == 4)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channels and, for sp, the filler */
+         {
+            sp += 4; dp += 3;
+         }
+
+         /* Note that the loop adds 3 to dp and 4 to sp each time. */
+         while (sp < ep)
+         {
+            *dp++ = *sp++; *dp++ = *sp++; *dp++ = *sp; sp += 2;
+         }
+
+         row_info->pixel_depth = 24;
+      }
+
+      else if (row_info->bit_depth == 16)
+      {
+         if (at_start != 0) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channels and, for sp, the filler */
+         {
+            sp += 8; dp += 6;
+         }
+
+         while (sp < ep)
+         {
+            /* Copy 6 bytes, skip 2 */
+            *dp++ = *sp++; *dp++ = *sp++;
+            *dp++ = *sp++; *dp++ = *sp++;
+            *dp++ = *sp++; *dp++ = *sp; sp += 3;
+         }
+
+         row_info->pixel_depth = 48;
+      }
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 3;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_RGB;
+   }
+
+   else
+      return; /* The filler channel has gone already */
+
+   /* Fix the rowbytes value. */
+   row_info->rowbytes = (png_size_t)(dp-row);
+}
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
+/* Swaps red and blue bytes within a pixel */
+void /* PRIVATE */
+png_do_bgr(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_bgr");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 3)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 4)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 2);
+               *(rp + 2) = save;
+            }
+         }
+      }
+
+#ifdef PNG_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 6)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         {
+            png_bytep rp;
+            png_uint_32 i;
+
+            for (i = 0, rp = row; i < row_width; i++, rp += 8)
+            {
+               png_byte save = *rp;
+               *rp = *(rp + 4);
+               *(rp + 4) = save;
+               save = *(rp + 1);
+               *(rp + 1) = *(rp + 5);
+               *(rp + 5) = save;
+            }
+         }
+      }
+#endif
+   }
+}
+#endif /* READ_BGR || WRITE_BGR */
+
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+/* Added at libpng-1.5.10 */
+void /* PRIVATE */
+png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
+{
+   if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
+      png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
+   {
+      /* Calculations moved outside switch in an attempt to stop different
+       * compiler warnings.  'padding' is in *bits* within the last byte, it is
+       * an 'int' because pixel_depth becomes an 'int' in the expression below,
+       * and this calculation is used because it avoids warnings that other
+       * forms produced on either GCC or MSVC.
+       */
+      int padding = PNG_PADBITS(row_info->pixel_depth, row_info->width);
+      png_bytep rp = png_ptr->row_buf + row_info->rowbytes - 1;
+
+      switch (row_info->bit_depth)
+      {
+         case 1:
+         {
+            /* in this case, all bytes must be 0 so we don't need
+             * to unpack the pixels except for the rightmost one.
+             */
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              if ((*rp >> padding) != 0)
+                 png_ptr->num_palette_max = 1;
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 2:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              int i = ((*rp >> padding) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 2) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 4) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 6) & 0x03);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 4:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+              int i = ((*rp >> padding) & 0x0f);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              i = (((*rp >> padding) >> 4) & 0x0f);
+
+              if (i > png_ptr->num_palette_max)
+                 png_ptr->num_palette_max = i;
+
+              padding = 0;
+            }
+
+            break;
+         }
+
+         case 8:
+         {
+            for (; rp > png_ptr->row_buf; rp--)
+            {
+               if (*rp > png_ptr->num_palette_max)
+                  png_ptr->num_palette_max = (int) *rp;
+            }
+
+            break;
+         }
+
+         default:
+            break;
+      }
+   }
+}
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+void PNGAPI
+png_set_user_transform_info(png_structrp png_ptr, png_voidp
+   user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+   png_debug(1, "in png_set_user_transform_info");
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+      (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+   {
+      png_app_error(png_ptr,
+          "info change after png_start_read_image or png_read_update_info");
+      return;
+   }
+#endif
+
+   png_ptr->user_transform_ptr = user_transform_ptr;
+   png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+   png_ptr->user_transform_channels = (png_byte)user_transform_channels;
+}
+#endif
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions.  The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+png_voidp PNGAPI
+png_get_user_transform_ptr(png_const_structrp png_ptr)
+{
+   if (png_ptr == NULL)
+      return (NULL);
+
+   return png_ptr->user_transform_ptr;
+}
+#endif
+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structrp png_ptr)
+{
+   /* See the comments in png.h - this is the sub-image row when reading an
+    * interlaced image.
+    */
+   if (png_ptr != NULL)
+      return png_ptr->row_number;
+
+   return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+      return png_ptr->pass;
+   return 8; /* invalid */
+}
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */
diff --git a/xs/src/png/libpng/pngwio.c b/xs/src/png/libpng/pngwio.c
new file mode 100644
index 000000000..37c7c3a7f
--- /dev/null
+++ b/xs/src/png/libpng/pngwio.c
@@ -0,0 +1,168 @@
+
+/* pngwio.c - functions for data output
+ *
+ * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * This file provides a location for all output.  Users who need
+ * special handling are expected to write functions that have the same
+ * arguments as these and perform similar functions, but that possibly
+ * use different output methods.  Note that you shouldn't change these
+ * functions, but rather write replacement functions and then change
+ * them at run time with png_set_write_fn(...).
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Write the data to whatever output you are using.  The default routine
+ * writes to a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered writes.  This should never be asked
+ * to write more than 64K on a 16-bit machine.
+ */
+
+void /* PRIVATE */
+png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
+{
+   /* NOTE: write_data_fn must not change the buffer! */
+   if (png_ptr->write_data_fn != NULL )
+      (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
+          length);
+
+   else
+      png_error(png_ptr, "Call to NULL write function");
+}
+
+#ifdef PNG_STDIO_SUPPORTED
+/* This is the function that does the actual writing of data.  If you are
+ * not writing to a standard C stream, you should create a replacement
+ * write_data function and use it at run time with png_set_write_fn(), rather
+ * than changing the library.
+ */
+void PNGCBAPI
+png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   if (png_ptr == NULL)
+      return;
+
+   check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
+
+   if (check != length)
+      png_error(png_ptr, "Write Error");
+}
+#endif
+
+/* This function is called to output any data pending writing (normally
+ * to disk).  After png_flush is called, there should be no data pending
+ * writing in any buffers.
+ */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+void /* PRIVATE */
+png_flush(png_structrp png_ptr)
+{
+   if (png_ptr->output_flush_fn != NULL)
+      (*(png_ptr->output_flush_fn))(png_ptr);
+}
+
+#  ifdef PNG_STDIO_SUPPORTED
+void PNGCBAPI
+png_default_flush(png_structp png_ptr)
+{
+   png_FILE_p io_ptr;
+
+   if (png_ptr == NULL)
+      return;
+
+   io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
+   fflush(io_ptr);
+}
+#  endif
+#endif
+
+/* This function allows the application to supply new output functions for
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr       - pointer to a png output data structure
+ * io_ptr        - pointer to user supplied structure containing info about
+ *                 the output functions.  May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ *                 arguments a pointer to a png_struct, a pointer to
+ *                 data to be written, and a 32-bit unsigned int that is
+ *                 the number of bytes to be written.  The new write
+ *                 function should call png_error(png_ptr, "Error msg")
+ *                 to exit and output any fatal error messages.  May be
+ *                 NULL, in which case libpng's default function will
+ *                 be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ *                 arguments a pointer to a png_struct.  After a call to
+ *                 the flush function, there should be no data in any buffers
+ *                 or pending transmission.  If the output method doesn't do
+ *                 any buffering of output, a function prototype must still be
+ *                 supplied although it doesn't have to do anything.  If
+ *                 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ *                 time, output_flush_fn will be ignored, although it must be
+ *                 supplied for compatibility.  May be NULL, in which case
+ *                 libpng's default function will be used, if
+ *                 PNG_WRITE_FLUSH_SUPPORTED is defined.  This is not
+ *                 a good idea if io_ptr does not point to a standard
+ *                 *FILE structure.
+ */
+void PNGAPI
+png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
+    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->io_ptr = io_ptr;
+
+#ifdef PNG_STDIO_SUPPORTED
+   if (write_data_fn != NULL)
+      png_ptr->write_data_fn = write_data_fn;
+
+   else
+      png_ptr->write_data_fn = png_default_write_data;
+#else
+   png_ptr->write_data_fn = write_data_fn;
+#endif
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_STDIO_SUPPORTED
+
+   if (output_flush_fn != NULL)
+      png_ptr->output_flush_fn = output_flush_fn;
+
+   else
+      png_ptr->output_flush_fn = png_default_flush;
+
+#  else
+   png_ptr->output_flush_fn = output_flush_fn;
+#  endif
+#else
+   PNG_UNUSED(output_flush_fn)
+#endif /* WRITE_FLUSH */
+
+#ifdef PNG_READ_SUPPORTED
+   /* It is an error to read while writing a png file */
+   if (png_ptr->read_data_fn != NULL)
+   {
+      png_ptr->read_data_fn = NULL;
+
+      png_warning(png_ptr,
+          "Can't set both read_data_fn and write_data_fn in the"
+          " same structure");
+   }
+#endif
+}
+#endif /* WRITE */
diff --git a/xs/src/png/libpng/pngwrite.c b/xs/src/png/libpng/pngwrite.c
new file mode 100644
index 000000000..a16d77ce0
--- /dev/null
+++ b/xs/src/png/libpng/pngwrite.c
@@ -0,0 +1,2396 @@
+
+/* pngwrite.c - general routines to write a PNG file
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+#  include <errno.h>
+#endif /* SIMPLIFIED_WRITE_STDIO */
+
+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+/* Write out all the unknown chunks for the current given location */
+static void
+write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
+    unsigned int where)
+{
+   if (info_ptr->unknown_chunks_num != 0)
+   {
+      png_const_unknown_chunkp up;
+
+      png_debug(5, "writing extra chunks");
+
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           ++up)
+         if ((up->location & where) != 0)
+      {
+         /* If per-chunk unknown chunk handling is enabled use it, otherwise
+          * just write the chunks the application has set.
+          */
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+         int keep = png_handle_as_unknown(png_ptr, up->name);
+
+         /* NOTE: this code is radically different from the read side in the
+          * matter of handling an ancillary unknown chunk.  In the read side
+          * the default behavior is to discard it, in the code below the default
+          * behavior is to write it.  Critical chunks are, however, only
+          * written if explicitly listed or if the default is set to write all
+          * unknown chunks.
+          *
+          * The default handling is also slightly weird - it is not possible to
+          * stop the writing of all unsafe-to-copy chunks!
+          *
+          * TODO: REVIEW: this would seem to be a bug.
+          */
+         if (keep != PNG_HANDLE_CHUNK_NEVER &&
+             ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ ||
+              keep == PNG_HANDLE_CHUNK_ALWAYS ||
+              (keep == PNG_HANDLE_CHUNK_AS_DEFAULT &&
+               png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS)))
+#endif
+         {
+            /* TODO: review, what is wrong with a zero length unknown chunk? */
+            if (up->size == 0)
+               png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+      }
+   }
+}
+#endif /* WRITE_UNKNOWN_CHUNKS */
+
+/* Writes all the PNG information.  This is the suggested way to use the
+ * library.  If you have a new chunk to add, make a function to write it,
+ * and put it in the correct location here.  If you want the chunk written
+ * after the image data, put it in png_write_end().  I strongly encourage
+ * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
+ * the chunk, as that will keep the code from breaking if you want to just
+ * write a plain PNG file.  If you have long comments, I suggest writing
+ * them in png_write_end(), and compressing them.
+ */
+void PNGAPI
+png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+   png_debug(1, "in png_write_info_before_PLTE");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
+   {
+      /* Write PNG signature */
+      png_write_sig(png_ptr);
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+      if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \
+          png_ptr->mng_features_permitted != 0)
+      {
+         png_warning(png_ptr,
+             "MNG features are not allowed in a PNG datastream");
+         png_ptr->mng_features_permitted = 0;
+      }
+#endif
+
+      /* Write IHDR information. */
+      png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+          info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
+          info_ptr->filter_type,
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+          info_ptr->interlace_type
+#else
+          0
+#endif
+         );
+
+      /* The rest of these check to see if the valid field has the appropriate
+       * flag set, and if it does, writes the chunk.
+       *
+       * 1.6.0: COLORSPACE support controls the writing of these chunks too, and
+       * the chunks will be written if the WRITE routine is there and
+       * information * is available in the COLORSPACE. (See
+       * png_colorspace_sync_info in png.c for where the valid flags get set.)
+       *
+       * Under certain circumstances the colorspace can be invalidated without
+       * syncing the info_struct 'valid' flags; this happens if libpng detects
+       * an error and calls png_error while the color space is being set, yet
+       * the application continues writing the PNG.  So check the 'invalid'
+       * flag here too.
+       */
+#ifdef PNG_GAMMA_SUPPORTED
+#  ifdef PNG_WRITE_gAMA_SUPPORTED
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+          (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 &&
+          (info_ptr->valid & PNG_INFO_gAMA) != 0)
+         png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma);
+#  endif
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+      /* Write only one of sRGB or an ICC profile.  If a profile was supplied
+       * and it matches one of the known sRGB ones issue a warning.
+       */
+#  ifdef PNG_WRITE_iCCP_SUPPORTED
+         if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+             (info_ptr->valid & PNG_INFO_iCCP) != 0)
+         {
+#    ifdef PNG_WRITE_sRGB_SUPPORTED
+               if ((info_ptr->valid & PNG_INFO_sRGB) != 0)
+                  png_app_warning(png_ptr,
+                      "profile matches sRGB but writing iCCP instead");
+#     endif
+
+            png_write_iCCP(png_ptr, info_ptr->iccp_name,
+                info_ptr->iccp_profile);
+         }
+#     ifdef PNG_WRITE_sRGB_SUPPORTED
+         else
+#     endif
+#  endif
+
+#  ifdef PNG_WRITE_sRGB_SUPPORTED
+         if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+             (info_ptr->valid & PNG_INFO_sRGB) != 0)
+            png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
+#  endif /* WRITE_sRGB */
+#endif /* COLORSPACE */
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+         if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+            png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+#  ifdef PNG_WRITE_cHRM_SUPPORTED
+         if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+             (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 &&
+             (info_ptr->valid & PNG_INFO_cHRM) != 0)
+            png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy);
+#  endif
+#endif
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+         write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR);
+#endif
+
+      png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+   }
+}
+
+void PNGAPI
+png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+   int i;
+#endif
+
+   png_debug(1, "in png_write_info");
+
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   png_write_info_before_PLTE(png_ptr, info_ptr);
+
+   if ((info_ptr->valid & PNG_INFO_PLTE) != 0)
+      png_write_PLTE(png_ptr, info_ptr->palette,
+          (png_uint_32)info_ptr->num_palette);
+
+   else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      png_error(png_ptr, "Valid palette required for paletted images");
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_tRNS) !=0)
+   {
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+      /* Invert the alpha channel (in tRNS) */
+      if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 &&
+          info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         int j, jend;
+
+         jend = info_ptr->num_trans;
+         if (jend > PNG_MAX_PALETTE_LENGTH)
+            jend = PNG_MAX_PALETTE_LENGTH;
+
+         for (j = 0; j<jend; ++j)
+            info_ptr->trans_alpha[j] =
+               (png_byte)(255 - info_ptr->trans_alpha[j]);
+      }
+#endif
+      png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
+          info_ptr->num_trans, info_ptr->color_type);
+   }
+#endif
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_bKGD) != 0)
+      png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
+      png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_hIST) != 0)
+      png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_oFFs) != 0)
+      png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
+          info_ptr->offset_unit_type);
+#endif
+
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_pCAL) != 0)
+      png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
+          info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
+          info_ptr->pcal_units, info_ptr->pcal_params);
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_sCAL) != 0)
+      png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+          info_ptr->scal_s_width, info_ptr->scal_s_height);
+#endif /* sCAL */
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_pHYs) != 0)
+      png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
+          info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
+#endif /* pHYs */
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_tIME) != 0)
+   {
+      png_write_tIME(png_ptr, &(info_ptr->mod_time));
+      png_ptr->mode |= PNG_WROTE_tIME;
+   }
+#endif /* tIME */
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_sPLT) != 0)
+      for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+         png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif /* sPLT */
+
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+   /* Check to see if we need to write text chunks */
+   for (i = 0; i < info_ptr->num_text; i++)
+   {
+      png_debug2(2, "Writing header text chunk %d, type %d", i,
+          info_ptr->text[i].compression);
+      /* An internationalized chunk? */
+      if (info_ptr->text[i].compression > 0)
+      {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+         /* Write international chunk */
+         png_write_iTXt(png_ptr,
+             info_ptr->text[i].compression,
+             info_ptr->text[i].key,
+             info_ptr->text[i].lang,
+             info_ptr->text[i].lang_key,
+             info_ptr->text[i].text);
+         /* Mark this chunk as written */
+         if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+         else
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+         png_warning(png_ptr, "Unable to write international text");
+#endif
+      }
+
+      /* If we want a compressed text chunk */
+      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
+      {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+         /* Write compressed chunk */
+         png_write_zTXt(png_ptr, info_ptr->text[i].key,
+             info_ptr->text[i].text, info_ptr->text[i].compression);
+         /* Mark this chunk as written */
+         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+         png_warning(png_ptr, "Unable to write compressed text");
+#endif
+      }
+
+      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+      {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+         /* Write uncompressed chunk */
+         png_write_tEXt(png_ptr, info_ptr->text[i].key,
+             info_ptr->text[i].text,
+             0);
+         /* Mark this chunk as written */
+         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+         /* Can't get here */
+         png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+      }
+   }
+#endif /* tEXt */
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+   write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE);
+#endif
+}
+
+/* Writes the end of the PNG file.  If you don't want to write comments or
+ * time information, you can pass NULL for info.  If you already wrote these
+ * in png_write_info(), do not write them again here.  If you have long
+ * comments, I suggest writing them here, and compressing them.
+ */
+void PNGAPI
+png_write_end(png_structrp png_ptr, png_inforp info_ptr)
+{
+   png_debug(1, "in png_write_end");
+
+   if (png_ptr == NULL)
+      return;
+
+   if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+      png_error(png_ptr, "No IDATs written into file");
+
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   if (png_ptr->num_palette_max > png_ptr->num_palette)
+      png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
+#endif
+
+   /* See if user wants us to write information chunks */
+   if (info_ptr != NULL)
+   {
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+      int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
+      /* Check to see if user has supplied a time chunk */
+      if ((info_ptr->valid & PNG_INFO_tIME) != 0 &&
+          (png_ptr->mode & PNG_WROTE_tIME) == 0)
+         png_write_tIME(png_ptr, &(info_ptr->mod_time));
+
+#endif
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+      /* Loop through comment chunks */
+      for (i = 0; i < info_ptr->num_text; i++)
+      {
+         png_debug2(2, "Writing trailer text chunk %d, type %d", i,
+             info_ptr->text[i].compression);
+         /* An internationalized chunk? */
+         if (info_ptr->text[i].compression > 0)
+         {
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+            /* Write international chunk */
+            png_write_iTXt(png_ptr,
+                info_ptr->text[i].compression,
+                info_ptr->text[i].key,
+                info_ptr->text[i].lang,
+                info_ptr->text[i].lang_key,
+                info_ptr->text[i].text);
+            /* Mark this chunk as written */
+            if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+               info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+            else
+               info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+            png_warning(png_ptr, "Unable to write international text");
+#endif
+         }
+
+         else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+         {
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+            /* Write compressed chunk */
+            png_write_zTXt(png_ptr, info_ptr->text[i].key,
+                info_ptr->text[i].text, info_ptr->text[i].compression);
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
+#else
+            png_warning(png_ptr, "Unable to write compressed text");
+#endif
+         }
+
+         else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+         {
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+            /* Write uncompressed chunk */
+            png_write_tEXt(png_ptr, info_ptr->text[i].key,
+                info_ptr->text[i].text, 0);
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#else
+            png_warning(png_ptr, "Unable to write uncompressed text");
+#endif
+         }
+      }
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
+      png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
+#endif
+
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+      write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
+#endif
+   }
+
+   png_ptr->mode |= PNG_AFTER_IDAT;
+
+   /* Write end of PNG file */
+   png_write_IEND(png_ptr);
+
+   /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+    * and restored again in libpng-1.2.30, may cause some applications that
+    * do not set png_ptr->output_flush_fn to crash.  If your application
+    * experiences a problem, please try building libpng with
+    * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+    * png-mng-implement at lists.sf.net .
+    */
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
+   png_flush(png_ptr);
+#  endif
+#endif
+}
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+void PNGAPI
+png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime)
+{
+   png_debug(1, "in png_convert_from_struct_tm");
+
+   ptime->year = (png_uint_16)(1900 + ttime->tm_year);
+   ptime->month = (png_byte)(ttime->tm_mon + 1);
+   ptime->day = (png_byte)ttime->tm_mday;
+   ptime->hour = (png_byte)ttime->tm_hour;
+   ptime->minute = (png_byte)ttime->tm_min;
+   ptime->second = (png_byte)ttime->tm_sec;
+}
+
+void PNGAPI
+png_convert_from_time_t(png_timep ptime, time_t ttime)
+{
+   struct tm *tbuf;
+
+   png_debug(1, "in png_convert_from_time_t");
+
+   tbuf = gmtime(&ttime);
+   png_convert_from_struct_tm(ptime, tbuf);
+}
+#endif
+
+/* Initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+{
+#ifndef PNG_USER_MEM_SUPPORTED
+   png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+       error_fn, warn_fn, NULL, NULL, NULL);
+#else
+   return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+       warn_fn, NULL, NULL, NULL);
+}
+
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+PNG_FUNCTION(png_structp,PNGAPI
+png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
+    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+{
+   png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
+       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+#endif /* USER_MEM */
+   if (png_ptr != NULL)
+   {
+      /* Set the zlib control values to defaults; they can be overridden by the
+       * application after the struct has been created.
+       */
+      png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
+
+      /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+       * pngwutil.c defaults it according to whether or not filters will be
+       * used, and ignores this setting.
+       */
+      png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+      png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
+      png_ptr->zlib_mem_level = 8;
+      png_ptr->zlib_window_bits = 15;
+      png_ptr->zlib_method = 8;
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+      png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+      png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
+      png_ptr->zlib_text_mem_level = 8;
+      png_ptr->zlib_text_window_bits = 15;
+      png_ptr->zlib_text_method = 8;
+#endif /* WRITE_COMPRESSED_TEXT */
+
+      /* This is a highly dubious configuration option; by default it is off,
+       * but it may be appropriate for private builds that are testing
+       * extensions not conformant to the current specification, or of
+       * applications that must not fail to write at all costs!
+       */
+#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+      /* In stable builds only warn if an application error can be completely
+       * handled.
+       */
+      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
+#endif
+
+      /* App warnings are warnings in release (or release candidate) builds but
+       * are errors during development.
+       */
+#if PNG_RELEASE_BUILD
+      png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+#endif
+
+      /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
+       * do it itself) avoiding setting the default function if it is not
+       * required.
+       */
+      png_set_write_fn(png_ptr, NULL, NULL, NULL);
+   }
+
+   return png_ptr;
+}
+
+
+/* Write a few rows of image data.  If the image is interlaced,
+ * either you will have to write the 7 sub images, or, if you
+ * have called png_set_interlace_handling(), you will have to
+ * "write" the image seven times.
+ */
+void PNGAPI
+png_write_rows(png_structrp png_ptr, png_bytepp row,
+    png_uint_32 num_rows)
+{
+   png_uint_32 i; /* row counter */
+   png_bytepp rp; /* row pointer */
+
+   png_debug(1, "in png_write_rows");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* Loop through the rows */
+   for (i = 0, rp = row; i < num_rows; i++, rp++)
+   {
+      png_write_row(png_ptr, *rp);
+   }
+}
+
+/* Write the image.  You only need to call this function once, even
+ * if you are writing an interlaced image.
+ */
+void PNGAPI
+png_write_image(png_structrp png_ptr, png_bytepp image)
+{
+   png_uint_32 i; /* row index */
+   int pass, num_pass; /* pass variables */
+   png_bytepp rp; /* points to current row */
+
+   if (png_ptr == NULL)
+      return;
+
+   png_debug(1, "in png_write_image");
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Initialize interlace handling.  If image is not interlaced,
+    * this will set pass to 1
+    */
+   num_pass = png_set_interlace_handling(png_ptr);
+#else
+   num_pass = 1;
+#endif
+   /* Loop through passes */
+   for (pass = 0; pass < num_pass; pass++)
+   {
+      /* Loop through image */
+      for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
+      {
+         png_write_row(png_ptr, *rp);
+      }
+   }
+}
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Performs intrapixel differencing  */
+static void
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_intrapixel");
+
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      int bytes_per_pixel;
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 3;
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 4;
+
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            *(rp)     = (png_byte)(*rp       - *(rp + 1));
+            *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1));
+         }
+      }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      else if (row_info->bit_depth == 16)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 6;
+
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 8;
+
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            png_uint_32 s0   = (png_uint_32)(*(rp    ) << 8) | *(rp + 1);
+            png_uint_32 s1   = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3);
+            png_uint_32 s2   = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5);
+            png_uint_32 red  = (png_uint_32)((s0 - s1) & 0xffffL);
+            png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+            *(rp    ) = (png_byte)(red >> 8);
+            *(rp + 1) = (png_byte)red;
+            *(rp + 4) = (png_byte)(blue >> 8);
+            *(rp + 5) = (png_byte)blue;
+         }
+      }
+#endif /* WRITE_16BIT */
+   }
+}
+#endif /* MNG_FEATURES */
+
+/* Called by user to write a row of image data */
+void PNGAPI
+png_write_row(png_structrp png_ptr, png_const_bytep row)
+{
+   /* 1.5.6: moved from png_struct to be a local structure: */
+   png_row_info row_info;
+
+   if (png_ptr == NULL)
+      return;
+
+   png_debug2(1, "in png_write_row (row %u, pass %d)",
+       png_ptr->row_number, png_ptr->pass);
+
+   /* Initialize transformations and other stuff if first time */
+   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
+   {
+      /* Make sure we wrote the header info */
+      if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
+         png_error(png_ptr,
+             "png_write_info was never called before png_write_row");
+
+      /* Check for transforms that have been set but were defined out */
+#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
+      if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+         png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
+      if ((png_ptr->transformations & PNG_FILLER) != 0)
+         png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
+#endif
+#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
+    defined(PNG_READ_PACKSWAP_SUPPORTED)
+      if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+         png_warning(png_ptr,
+             "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
+      if ((png_ptr->transformations & PNG_PACK) != 0)
+         png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
+      if ((png_ptr->transformations & PNG_SHIFT) != 0)
+         png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
+      if ((png_ptr->transformations & PNG_BGR) != 0)
+         png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
+#endif
+
+#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
+      if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+         png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
+#endif
+
+      png_write_start_row(png_ptr);
+   }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* If interlaced and not interested in row, return */
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
+   {
+      switch (png_ptr->pass)
+      {
+         case 0:
+            if ((png_ptr->row_number & 0x07) != 0)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 1:
+            if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 2:
+            if ((png_ptr->row_number & 0x07) != 4)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 3:
+            if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 4:
+            if ((png_ptr->row_number & 0x03) != 2)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 5:
+            if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         case 6:
+            if ((png_ptr->row_number & 0x01) == 0)
+            {
+               png_write_finish_row(png_ptr);
+               return;
+            }
+            break;
+
+         default: /* error: ignore it */
+            break;
+      }
+   }
+#endif
+
+   /* Set up row info for transformations */
+   row_info.color_type = png_ptr->color_type;
+   row_info.width = png_ptr->usr_width;
+   row_info.channels = png_ptr->usr_channels;
+   row_info.bit_depth = png_ptr->usr_bit_depth;
+   row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
+   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
+
+   png_debug1(3, "row_info->color_type = %d", row_info.color_type);
+   png_debug1(3, "row_info->width = %u", row_info.width);
+   png_debug1(3, "row_info->channels = %d", row_info.channels);
+   png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
+   png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
+   png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
+
+   /* Copy user's row into buffer, leaving room for filter byte. */
+   memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Handle interlacing */
+   if (png_ptr->interlaced && png_ptr->pass < 6 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
+   {
+      png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
+      /* This should always get caught above, but still ... */
+      if (row_info.width == 0)
+      {
+         png_write_finish_row(png_ptr);
+         return;
+      }
+   }
+#endif
+
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+   /* Handle other transformations */
+   if (png_ptr->transformations != 0)
+      png_do_write_transformations(png_ptr, &row_info);
+#endif
+
+   /* At this point the row_info pixel depth must match the 'transformed' depth,
+    * which is also the output depth.
+    */
+   if (row_info.pixel_depth != png_ptr->pixel_depth ||
+       row_info.pixel_depth != png_ptr->transformed_pixel_depth)
+      png_error(png_ptr, "internal write transform logic error");
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   /* Write filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not write a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
+   {
+      /* Intrapixel differencing */
+      png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
+   }
+#endif
+
+/* Added at libpng-1.5.10 */
+#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+   /* Check for out-of-range palette index */
+   if (row_info.color_type == PNG_COLOR_TYPE_PALETTE &&
+       png_ptr->num_palette_max >= 0)
+      png_do_check_palette_indexes(png_ptr, &row_info);
+#endif
+
+   /* Find a filter if necessary, filter the row and write it out. */
+   png_write_find_filter(png_ptr, &row_info);
+
+   if (png_ptr->write_row_fn != NULL)
+      (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
+}
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+/* Set the automatic flush interval or 0 to turn flushing off */
+void PNGAPI
+png_set_flush(png_structrp png_ptr, int nrows)
+{
+   png_debug(1, "in png_set_flush");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->flush_dist = (nrows < 0 ? 0 : (png_uint_32)nrows);
+}
+
+/* Flush the current output buffers now */
+void PNGAPI
+png_write_flush(png_structrp png_ptr)
+{
+   png_debug(1, "in png_write_flush");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* We have already written out all of the data */
+   if (png_ptr->row_number >= png_ptr->num_rows)
+      return;
+
+   png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH);
+   png_ptr->flush_rows = 0;
+   png_flush(png_ptr);
+}
+#endif /* WRITE_FLUSH */
+
+/* Free any memory used in png_ptr struct without freeing the struct itself. */
+static void
+png_write_destroy(png_structrp png_ptr)
+{
+   png_debug(1, "in png_write_destroy");
+
+   /* Free any memory zlib uses */
+   if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+      deflateEnd(&png_ptr->zstream);
+
+   /* Free our memory.  png_free checks NULL for us. */
+   png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+   png_free(png_ptr, png_ptr->row_buf);
+   png_ptr->row_buf = NULL;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_free(png_ptr, png_ptr->prev_row);
+   png_free(png_ptr, png_ptr->try_row);
+   png_free(png_ptr, png_ptr->tst_row);
+   png_ptr->prev_row = NULL;
+   png_ptr->try_row = NULL;
+   png_ptr->tst_row = NULL;
+#endif
+
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   png_free(png_ptr, png_ptr->chunk_list);
+   png_ptr->chunk_list = NULL;
+#endif
+
+   /* The error handling and memory handling information is left intact at this
+    * point: the jmp_buf may still have to be freed.  See png_destroy_png_struct
+    * for how this happens.
+    */
+}
+
+/* Free all memory used by the write.
+ * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for
+ * *png_ptr_ptr.  Prior to 1.6.0 it would accept such a value and it would free
+ * the passed in info_structs but it would quietly fail to free any of the data
+ * inside them.  In 1.6.0 it quietly does nothing (it has to be quiet because it
+ * has no png_ptr.)
+ */
+void PNGAPI
+png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
+{
+   png_debug(1, "in png_destroy_write_struct");
+
+   if (png_ptr_ptr != NULL)
+   {
+      png_structrp png_ptr = *png_ptr_ptr;
+
+      if (png_ptr != NULL) /* added in libpng 1.6.0 */
+      {
+         png_destroy_info_struct(png_ptr, info_ptr_ptr);
+
+         *png_ptr_ptr = NULL;
+         png_write_destroy(png_ptr);
+         png_destroy_png_struct(png_ptr);
+      }
+   }
+}
+
+/* Allow the application to select one or more row filters to use. */
+void PNGAPI
+png_set_filter(png_structrp png_ptr, int method, int filters)
+{
+   png_debug(1, "in png_set_filter");
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+       (method == PNG_INTRAPIXEL_DIFFERENCING))
+      method = PNG_FILTER_TYPE_BASE;
+
+#endif
+   if (method == PNG_FILTER_TYPE_BASE)
+   {
+      switch (filters & (PNG_ALL_FILTERS | 0x07))
+      {
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+         case 5:
+         case 6:
+         case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
+#endif /* WRITE_FILTER */
+            /* FALLTHROUGH */
+         case PNG_FILTER_VALUE_NONE:
+            png_ptr->do_filter = PNG_FILTER_NONE; break;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+         case PNG_FILTER_VALUE_SUB:
+            png_ptr->do_filter = PNG_FILTER_SUB; break;
+
+         case PNG_FILTER_VALUE_UP:
+            png_ptr->do_filter = PNG_FILTER_UP; break;
+
+         case PNG_FILTER_VALUE_AVG:
+            png_ptr->do_filter = PNG_FILTER_AVG; break;
+
+         case PNG_FILTER_VALUE_PAETH:
+            png_ptr->do_filter = PNG_FILTER_PAETH; break;
+
+         default:
+            png_ptr->do_filter = (png_byte)filters; break;
+#else
+         default:
+            png_app_error(png_ptr, "Unknown row filter for method 0");
+#endif /* WRITE_FILTER */
+      }
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+      /* If we have allocated the row_buf, this means we have already started
+       * with the image and we should have allocated all of the filter buffers
+       * that have been selected.  If prev_row isn't already allocated, then
+       * it is too late to start using the filters that need it, since we
+       * will be missing the data in the previous row.  If an application
+       * wants to start and stop using particular filters during compression,
+       * it should start out with all of the filters, and then remove them
+       * or add them back after the start of compression.
+       *
+       * NOTE: this is a nasty constraint on the code, because it means that the
+       * prev_row buffer must be maintained even if there are currently no
+       * 'prev_row' requiring filters active.
+       */
+      if (png_ptr->row_buf != NULL)
+      {
+         int num_filters;
+         png_alloc_size_t buf_size;
+
+         /* Repeat the checks in png_write_start_row; 1 pixel high or wide
+          * images cannot benefit from certain filters.  If this isn't done here
+          * the check below will fire on 1 pixel high images.
+          */
+         if (png_ptr->height == 1)
+            filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+         if (png_ptr->width == 1)
+            filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+         if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0
+            && png_ptr->prev_row == NULL)
+         {
+            /* This is the error case, however it is benign - the previous row
+             * is not available so the filter can't be used.  Just warn here.
+             */
+            png_app_warning(png_ptr,
+                "png_set_filter: UP/AVG/PAETH cannot be added after start");
+            filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+         }
+
+         num_filters = 0;
+
+         if (filters & PNG_FILTER_SUB)
+            num_filters++;
+
+         if (filters & PNG_FILTER_UP)
+            num_filters++;
+
+         if (filters & PNG_FILTER_AVG)
+            num_filters++;
+
+         if (filters & PNG_FILTER_PAETH)
+            num_filters++;
+
+         /* Allocate needed row buffers if they have not already been
+          * allocated.
+          */
+         buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth,
+             png_ptr->width) + 1;
+
+         if (png_ptr->try_row == NULL)
+            png_ptr->try_row = png_voidcast(png_bytep,
+                png_malloc(png_ptr, buf_size));
+
+         if (num_filters > 1)
+         {
+            if (png_ptr->tst_row == NULL)
+               png_ptr->tst_row = png_voidcast(png_bytep,
+                   png_malloc(png_ptr, buf_size));
+         }
+      }
+      png_ptr->do_filter = (png_byte)filters;
+#endif
+   }
+   else
+      png_error(png_ptr, "Unknown custom filter method");
+}
+
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
+/* Provide floating and fixed point APIs */
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
+    int num_weights, png_const_doublep filter_weights,
+    png_const_doublep filter_costs)
+{
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(heuristic_method)
+   PNG_UNUSED(num_weights)
+   PNG_UNUSED(filter_weights)
+   PNG_UNUSED(filter_costs)
+}
+#endif /* FLOATING_POINT */
+
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void PNGAPI
+png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
+    int num_weights, png_const_fixed_point_p filter_weights,
+    png_const_fixed_point_p filter_costs)
+{
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(heuristic_method)
+   PNG_UNUSED(num_weights)
+   PNG_UNUSED(filter_weights)
+   PNG_UNUSED(filter_costs)
+}
+#endif /* FIXED_POINT */
+#endif /* WRITE_WEIGHTED_FILTER */
+
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_compression_level(png_structrp png_ptr, int level)
+{
+   png_debug(1, "in png_set_compression_level");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->zlib_level = level;
+}
+
+void PNGAPI
+png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
+{
+   png_debug(1, "in png_set_compression_mem_level");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->zlib_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_compression_strategy(png_structrp png_ptr, int strategy)
+{
+   png_debug(1, "in png_set_compression_strategy");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* The flag setting here prevents the libpng dynamic selection of strategy.
+    */
+   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
+   png_ptr->zlib_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
+{
+   if (png_ptr == NULL)
+      return;
+
+   /* Prior to 1.6.0 this would warn but then set the window_bits value. This
+    * meant that negative window bits values could be selected that would cause
+    * libpng to write a non-standard PNG file with raw deflate or gzip
+    * compressed IDAT or ancillary chunks.  Such files can be read and there is
+    * no warning on read, so this seems like a very bad idea.
+    */
+   if (window_bits > 15)
+   {
+      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+      window_bits = 15;
+   }
+
+   else if (window_bits < 8)
+   {
+      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+      window_bits = 8;
+   }
+
+   png_ptr->zlib_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_compression_method(png_structrp png_ptr, int method)
+{
+   png_debug(1, "in png_set_compression_method");
+
+   if (png_ptr == NULL)
+      return;
+
+   /* This would produce an invalid PNG file if it worked, but it doesn't and
+    * deflate will fault it, so it is harmless to just warn here.
+    */
+   if (method != 8)
+      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+   png_ptr->zlib_method = method;
+}
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
+
+/* The following were added to libpng-1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_text_compression_level(png_structrp png_ptr, int level)
+{
+   png_debug(1, "in png_set_text_compression_level");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->zlib_text_level = level;
+}
+
+void PNGAPI
+png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
+{
+   png_debug(1, "in png_set_text_compression_mem_level");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->zlib_text_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
+{
+   png_debug(1, "in png_set_text_compression_strategy");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->zlib_text_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
+{
+   if (png_ptr == NULL)
+      return;
+
+   if (window_bits > 15)
+   {
+      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+      window_bits = 15;
+   }
+
+   else if (window_bits < 8)
+   {
+      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+      window_bits = 8;
+   }
+
+   png_ptr->zlib_text_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_text_compression_method(png_structrp png_ptr, int method)
+{
+   png_debug(1, "in png_set_text_compression_method");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (method != 8)
+      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+   png_ptr->zlib_text_method = method;
+}
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+/* end of API added to libpng-1.5.4 */
+
+void PNGAPI
+png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
+{
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->write_row_fn = write_row_fn;
+}
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+void PNGAPI
+png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
+    write_user_transform_fn)
+{
+   png_debug(1, "in png_set_write_user_transform_fn");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_USER_TRANSFORM;
+   png_ptr->write_user_transform_fn = write_user_transform_fn;
+}
+#endif
+
+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structrp png_ptr, png_inforp info_ptr,
+    int transforms, voidp params)
+{
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   if ((info_ptr->valid & PNG_INFO_IDAT) == 0)
+   {
+      png_app_error(png_ptr, "no rows for png_write_image to write");
+      return;
+   }
+
+   /* Write the file header information. */
+   png_write_info(png_ptr, info_ptr);
+
+   /* ------ these transformations don't touch the info structure ------- */
+
+   /* Invert monochrome pixels */
+   if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+      png_set_invert_mono(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported");
+#endif
+
+   /* Shift the pixels up to a legal bit depth and fill in
+    * as appropriate to correctly scale the image.
+    */
+   if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+      if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
+         png_set_shift(png_ptr, &info_ptr->sig_bit);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
+#endif
+
+   /* Pack pixels into bytes */
+   if ((transforms & PNG_TRANSFORM_PACKING) != 0)
+#ifdef PNG_WRITE_PACK_SUPPORTED
+      png_set_packing(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported");
+#endif
+
+   /* Swap location of alpha bytes from ARGB to RGBA */
+   if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+      png_set_swap_alpha(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported");
+#endif
+
+   /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into
+    * RGB, note that the code expects the input color type to be G or RGB; no
+    * alpha channel.
+    */
+   if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER|
+       PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0)
+   {
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+      if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0)
+      {
+         if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
+            png_app_error(png_ptr,
+                "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
+
+         /* Continue if ignored - this is the pre-1.6.10 behavior */
+         png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+      }
+
+      else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
+         png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
+#endif
+   }
+
+   /* Flip BGR pixels to RGB */
+   if ((transforms & PNG_TRANSFORM_BGR) != 0)
+#ifdef PNG_WRITE_BGR_SUPPORTED
+      png_set_bgr(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported");
+#endif
+
+   /* Swap bytes of 16-bit files to most significant byte first */
+   if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+      png_set_swap(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported");
+#endif
+
+   /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */
+   if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+      png_set_packswap(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported");
+#endif
+
+   /* Invert the alpha channel from opacity to transparency */
+   if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+      png_set_invert_alpha(png_ptr);
+#else
+      png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported");
+#endif
+
+   /* ----------------------- end of transformations ------------------- */
+
+   /* Write the bits */
+   png_write_image(png_ptr, info_ptr->row_pointers);
+
+   /* It is REQUIRED to call this to finish writing the rest of the file */
+   png_write_end(png_ptr, info_ptr);
+
+   PNG_UNUSED(params)
+}
+#endif
+
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+/* Initialize the write structure - general purpose utility. */
+static int
+png_image_write_init(png_imagep image)
+{
+   png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
+       png_safe_error, png_safe_warning);
+
+   if (png_ptr != NULL)
+   {
+      png_infop info_ptr = png_create_info_struct(png_ptr);
+
+      if (info_ptr != NULL)
+      {
+         png_controlp control = png_voidcast(png_controlp,
+             png_malloc_warn(png_ptr, (sizeof *control)));
+
+         if (control != NULL)
+         {
+            memset(control, 0, (sizeof *control));
+
+            control->png_ptr = png_ptr;
+            control->info_ptr = info_ptr;
+            control->for_write = 1;
+
+            image->opaque = control;
+            return 1;
+         }
+
+         /* Error clean up */
+         png_destroy_info_struct(png_ptr, &info_ptr);
+      }
+
+      png_destroy_write_struct(&png_ptr, NULL);
+   }
+
+   return png_image_error(image, "png_image_write_: out of memory");
+}
+
+/* Arguments to png_image_write_main: */
+typedef struct
+{
+   /* Arguments: */
+   png_imagep      image;
+   png_const_voidp buffer;
+   png_int_32      row_stride;
+   png_const_voidp colormap;
+   int             convert_to_8bit;
+   /* Local variables: */
+   png_const_voidp first_row;
+   ptrdiff_t       row_bytes;
+   png_voidp       local_row;
+   /* Byte count for memory writing */
+   png_bytep        memory;
+   png_alloc_size_t memory_bytes; /* not used for STDIO */
+   png_alloc_size_t output_bytes; /* running total */
+} png_image_write_control;
+
+/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
+ * do any necessary byte swapping.  The component order is defined by the
+ * png_image format value.
+ */
+static int
+png_write_image_16bit(png_voidp argument)
+{
+   png_image_write_control *display = png_voidcast(png_image_write_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+
+   png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+       display->first_row);
+   png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
+   png_uint_16p row_end;
+   const unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ?
+       3 : 1;
+   int aindex = 0;
+   png_uint_32 y = image->height;
+
+   if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+   {
+#   ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+      if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+      {
+         aindex = -1;
+         ++input_row; /* To point to the first component */
+         ++output_row;
+      }
+         else
+            aindex = (int)channels;
+#     else
+         aindex = (int)channels;
+#     endif
+   }
+
+   else
+      png_error(png_ptr, "png_write_image: internal call error");
+
+   /* Work out the output row end and count over this, note that the increment
+    * above to 'row' means that row_end can actually be beyond the end of the
+    * row; this is correct.
+    */
+   row_end = output_row + image->width * (channels+1);
+
+   for (; y > 0; --y)
+   {
+      png_const_uint_16p in_ptr = input_row;
+      png_uint_16p out_ptr = output_row;
+
+      while (out_ptr < row_end)
+      {
+         const png_uint_16 alpha = in_ptr[aindex];
+         png_uint_32 reciprocal = 0;
+         int c;
+
+         out_ptr[aindex] = alpha;
+
+         /* Calculate a reciprocal.  The correct calculation is simply
+          * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
+          * allows correct rounding by adding .5 before the shift.  'reciprocal'
+          * is only initialized when required.
+          */
+         if (alpha > 0 && alpha < 65535)
+            reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
+
+         c = (int)channels;
+         do /* always at least one channel */
+         {
+            png_uint_16 component = *in_ptr++;
+
+            /* The following gives 65535 for an alpha of 0, which is fine,
+             * otherwise if 0/0 is represented as some other value there is more
+             * likely to be a discontinuity which will probably damage
+             * compression when moving from a fully transparent area to a
+             * nearly transparent one.  (The assumption here is that opaque
+             * areas tend not to be 0 intensity.)
+             */
+            if (component >= alpha)
+               component = 65535;
+
+            /* component<alpha, so component/alpha is less than one and
+             * component*reciprocal is less than 2^31.
+             */
+            else if (component > 0 && alpha < 65535)
+            {
+               png_uint_32 calc = component * reciprocal;
+               calc += 16384; /* round to nearest */
+               component = (png_uint_16)(calc >> 15);
+            }
+
+            *out_ptr++ = component;
+         }
+         while (--c > 0);
+
+         /* Skip to next component (skip the intervening alpha channel) */
+         ++in_ptr;
+         ++out_ptr;
+      }
+
+      png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
+      input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+   }
+
+   return 1;
+}
+
+/* Given 16-bit input (1 to 4 channels) write 8-bit output.  If an alpha channel
+ * is present it must be removed from the components, the components are then
+ * written in sRGB encoding.  No components are added or removed.
+ *
+ * Calculate an alpha reciprocal to reverse pre-multiplication.  As above the
+ * calculation can be done to 15 bits of accuracy; however, the output needs to
+ * be scaled in the range 0..255*65535, so include that scaling here.
+ */
+#   define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha)
+
+static png_byte
+png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
+    png_uint_32 reciprocal/*from the above macro*/)
+{
+   /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
+    * is represented as some other value there is more likely to be a
+    * discontinuity which will probably damage compression when moving from a
+    * fully transparent area to a nearly transparent one.  (The assumption here
+    * is that opaque areas tend not to be 0 intensity.)
+    *
+    * There is a rounding problem here; if alpha is less than 128 it will end up
+    * as 0 when scaled to 8 bits.  To avoid introducing spurious colors into the
+    * output change for this too.
+    */
+   if (component >= alpha || alpha < 128)
+      return 255;
+
+   /* component<alpha, so component/alpha is less than one and
+    * component*reciprocal is less than 2^31.
+    */
+   else if (component > 0)
+   {
+      /* The test is that alpha/257 (rounded) is less than 255, the first value
+       * that becomes 255 is 65407.
+       * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
+       * be exact!)  [Could also test reciprocal != 0]
+       */
+      if (alpha < 65407)
+      {
+         component *= reciprocal;
+         component += 64; /* round to nearest */
+         component >>= 7;
+      }
+
+      else
+         component *= 255;
+
+      /* Convert the component to sRGB. */
+      return (png_byte)PNG_sRGB_FROM_LINEAR(component);
+   }
+
+   else
+      return 0;
+}
+
+static int
+png_write_image_8bit(png_voidp argument)
+{
+   png_image_write_control *display = png_voidcast(png_image_write_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+
+   png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+       display->first_row);
+   png_bytep output_row = png_voidcast(png_bytep, display->local_row);
+   png_uint_32 y = image->height;
+   const unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ?
+       3 : 1;
+
+   if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
+   {
+      png_bytep row_end;
+      int aindex;
+
+#   ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+      if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
+      {
+         aindex = -1;
+         ++input_row; /* To point to the first component */
+         ++output_row;
+      }
+
+      else
+#   endif
+      aindex = (int)channels;
+
+      /* Use row_end in place of a loop counter: */
+      row_end = output_row + image->width * (channels+1);
+
+      for (; y > 0; --y)
+      {
+         png_const_uint_16p in_ptr = input_row;
+         png_bytep out_ptr = output_row;
+
+         while (out_ptr < row_end)
+         {
+            png_uint_16 alpha = in_ptr[aindex];
+            png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+            png_uint_32 reciprocal = 0;
+            int c;
+
+            /* Scale and write the alpha channel. */
+            out_ptr[aindex] = alphabyte;
+
+            if (alphabyte > 0 && alphabyte < 255)
+               reciprocal = UNP_RECIPROCAL(alpha);
+
+            c = (int)channels;
+            do /* always at least one channel */
+               *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
+            while (--c > 0);
+
+            /* Skip to next component (skip the intervening alpha channel) */
+            ++in_ptr;
+            ++out_ptr;
+         } /* while out_ptr < row_end */
+
+         png_write_row(png_ptr, png_voidcast(png_const_bytep,
+             display->local_row));
+         input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+      } /* while y */
+   }
+
+   else
+   {
+      /* No alpha channel, so the row_end really is the end of the row and it
+       * is sufficient to loop over the components one by one.
+       */
+      png_bytep row_end = output_row + image->width * channels;
+
+      for (; y > 0; --y)
+      {
+         png_const_uint_16p in_ptr = input_row;
+         png_bytep out_ptr = output_row;
+
+         while (out_ptr < row_end)
+         {
+            png_uint_32 component = *in_ptr++;
+
+            component *= 255;
+            *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
+         }
+
+         png_write_row(png_ptr, output_row);
+         input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+      }
+   }
+
+   return 1;
+}
+
+static void
+png_image_set_PLTE(png_image_write_control *display)
+{
+   const png_imagep image = display->image;
+   const void *cmap = display->colormap;
+   const int entries = image->colormap_entries > 256 ? 256 :
+       (int)image->colormap_entries;
+
+   /* NOTE: the caller must check for cmap != NULL and entries != 0 */
+   const png_uint_32 format = image->format;
+   const unsigned int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
+
+#   if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
+      defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED)
+      const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+          (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+#   else
+#     define afirst 0
+#   endif
+
+#   ifdef PNG_FORMAT_BGR_SUPPORTED
+      const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
+#   else
+#     define bgr 0
+#   endif
+
+   int i, num_trans;
+   png_color palette[256];
+   png_byte tRNS[256];
+
+   memset(tRNS, 255, (sizeof tRNS));
+   memset(palette, 0, (sizeof palette));
+
+   for (i=num_trans=0; i<entries; ++i)
+   {
+      /* This gets automatically converted to sRGB with reversal of the
+       * pre-multiplication if the color-map has an alpha channel.
+       */
+      if ((format & PNG_FORMAT_FLAG_LINEAR) != 0)
+      {
+         png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
+
+         entry += (unsigned int)i * channels;
+
+         if ((channels & 1) != 0) /* no alpha */
+         {
+            if (channels >= 3) /* RGB */
+            {
+               palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+                   entry[(2 ^ bgr)]);
+               palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+                   entry[1]);
+               palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+                   entry[bgr]);
+            }
+
+            else /* Gray */
+               palette[i].blue = palette[i].red = palette[i].green =
+                  (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
+         }
+
+         else /* alpha */
+         {
+            png_uint_16 alpha = entry[afirst ? 0 : channels-1];
+            png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+            png_uint_32 reciprocal = 0;
+
+            /* Calculate a reciprocal, as in the png_write_image_8bit code above
+             * this is designed to produce a value scaled to 255*65535 when
+             * divided by 128 (i.e. asr 7).
+             */
+            if (alphabyte > 0 && alphabyte < 255)
+               reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
+
+            tRNS[i] = alphabyte;
+            if (alphabyte < 255)
+               num_trans = i+1;
+
+            if (channels >= 3) /* RGB */
+            {
+               palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
+                   alpha, reciprocal);
+               palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
+                   reciprocal);
+               palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
+                   reciprocal);
+            }
+
+            else /* gray */
+               palette[i].blue = palette[i].red = palette[i].green =
+                   png_unpremultiply(entry[afirst], alpha, reciprocal);
+         }
+      }
+
+      else /* Color-map has sRGB values */
+      {
+         png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
+
+         entry += (unsigned int)i * channels;
+
+         switch (channels)
+         {
+            case 4:
+               tRNS[i] = entry[afirst ? 0 : 3];
+               if (tRNS[i] < 255)
+                  num_trans = i+1;
+               /* FALLTHROUGH */
+            case 3:
+               palette[i].blue = entry[afirst + (2 ^ bgr)];
+               palette[i].green = entry[afirst + 1];
+               palette[i].red = entry[afirst + bgr];
+               break;
+
+            case 2:
+               tRNS[i] = entry[1 ^ afirst];
+               if (tRNS[i] < 255)
+                  num_trans = i+1;
+               /* FALLTHROUGH */
+            case 1:
+               palette[i].blue = palette[i].red = palette[i].green =
+                  entry[afirst];
+               break;
+
+            default:
+               break;
+         }
+      }
+   }
+
+#   ifdef afirst
+#     undef afirst
+#   endif
+#   ifdef bgr
+#     undef bgr
+#   endif
+
+   png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
+       entries);
+
+   if (num_trans > 0)
+      png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
+          num_trans, NULL);
+
+   image->colormap_entries = (png_uint_32)entries;
+}
+
+static int
+png_image_write_main(png_voidp argument)
+{
+   png_image_write_control *display = png_voidcast(png_image_write_control*,
+       argument);
+   png_imagep image = display->image;
+   png_structrp png_ptr = image->opaque->png_ptr;
+   png_inforp info_ptr = image->opaque->info_ptr;
+   png_uint_32 format = image->format;
+
+   /* The following four ints are actually booleans */
+   int colormap = (format & PNG_FORMAT_FLAG_COLORMAP);
+   int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */
+   int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA);
+   int write_16bit = linear && (display->convert_to_8bit == 0);
+
+#   ifdef PNG_BENIGN_ERRORS_SUPPORTED
+      /* Make sure we error out on any bad situation */
+      png_set_benign_errors(png_ptr, 0/*error*/);
+#   endif
+
+   /* Default the 'row_stride' parameter if required, also check the row stride
+    * and total image size to ensure that they are within the system limits.
+    */
+   {
+      const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format);
+
+      if (image->width <= 0x7fffffffU/channels) /* no overflow */
+      {
+         png_uint_32 check;
+         const png_uint_32 png_row_stride = image->width * channels;
+
+         if (display->row_stride == 0)
+            display->row_stride = (png_int_32)/*SAFE*/png_row_stride;
+
+         if (display->row_stride < 0)
+            check = (png_uint_32)(-display->row_stride);
+
+         else
+            check = (png_uint_32)display->row_stride;
+
+         if (check >= png_row_stride)
+         {
+            /* Now check for overflow of the image buffer calculation; this
+             * limits the whole image size to 32 bits for API compatibility with
+             * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro.
+             */
+            if (image->height > 0xffffffffU/png_row_stride)
+               png_error(image->opaque->png_ptr, "memory image too large");
+         }
+
+         else
+            png_error(image->opaque->png_ptr, "supplied row stride too small");
+      }
+
+      else
+         png_error(image->opaque->png_ptr, "image row stride too large");
+   }
+
+   /* Set the required transforms then write the rows in the correct order. */
+   if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0)
+   {
+      if (display->colormap != NULL && image->colormap_entries > 0)
+      {
+         png_uint_32 entries = image->colormap_entries;
+
+         png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+             entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
+             PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+             PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+         png_image_set_PLTE(display);
+      }
+
+      else
+         png_error(image->opaque->png_ptr,
+             "no color-map for color-mapped image");
+   }
+
+   else
+      png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+          write_16bit ? 16 : 8,
+          ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
+          ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
+          PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+   /* Counter-intuitively the data transformations must be called *after*
+    * png_write_info, not before as in the read code, but the 'set' functions
+    * must still be called before.  Just set the color space information, never
+    * write an interlaced image.
+    */
+
+   if (write_16bit != 0)
+   {
+      /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
+      png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
+
+      if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
+         png_set_cHRM_fixed(png_ptr, info_ptr,
+             /* color      x       y */
+             /* white */ 31270, 32900,
+             /* red   */ 64000, 33000,
+             /* green */ 30000, 60000,
+             /* blue  */ 15000,  6000
+         );
+   }
+
+   else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
+      png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
+
+   /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
+    * space must still be gamma encoded.
+    */
+   else
+      png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+
+   /* Write the file header. */
+   png_write_info(png_ptr, info_ptr);
+
+   /* Now set up the data transformations (*after* the header is written),
+    * remove the handled transformations from the 'format' flags for checking.
+    *
+    * First check for a little endian system if writing 16-bit files.
+    */
+   if (write_16bit != 0)
+   {
+      PNG_CONST png_uint_16 le = 0x0001;
+
+      if ((*(png_const_bytep) & le) != 0)
+         png_set_swap(png_ptr);
+   }
+
+#   ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+      if ((format & PNG_FORMAT_FLAG_BGR) != 0)
+      {
+         if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0)
+            png_set_bgr(png_ptr);
+         format &= ~PNG_FORMAT_FLAG_BGR;
+      }
+#   endif
+
+#   ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+      if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
+      {
+         if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+            png_set_swap_alpha(png_ptr);
+         format &= ~PNG_FORMAT_FLAG_AFIRST;
+      }
+#   endif
+
+   /* If there are 16 or fewer color-map entries we wrote a lower bit depth
+    * above, but the application data is still byte packed.
+    */
+   if (colormap != 0 && image->colormap_entries <= 16)
+      png_set_packing(png_ptr);
+
+   /* That should have handled all (both) the transforms. */
+   if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
+         PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
+      png_error(png_ptr, "png_write_image: unsupported transformation");
+
+   {
+      png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
+      ptrdiff_t row_bytes = display->row_stride;
+
+      if (linear != 0)
+         row_bytes *= (sizeof (png_uint_16));
+
+      if (row_bytes < 0)
+         row += (image->height-1) * (-row_bytes);
+
+      display->first_row = row;
+      display->row_bytes = row_bytes;
+   }
+
+   /* Apply 'fast' options if the flag is set. */
+   if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
+   {
+      png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
+      /* NOTE: determined by experiment using pngstest, this reflects some
+       * balance between the time to write the image once and the time to read
+       * it about 50 times.  The speed-up in pngstest was about 10-20% of the
+       * total (user) time on a heavily loaded system.
+       */
+#   ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+      png_set_compression_level(png_ptr, 3);
+#   endif
+   }
+
+   /* Check for the cases that currently require a pre-transform on the row
+    * before it is written.  This only applies when the input is 16-bit and
+    * either there is an alpha channel or it is converted to 8-bit.
+    */
+   if ((linear != 0 && alpha != 0 ) ||
+       (colormap == 0 && display->convert_to_8bit != 0))
+   {
+      png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
+          png_get_rowbytes(png_ptr, info_ptr)));
+      int result;
+
+      display->local_row = row;
+      if (write_16bit != 0)
+         result = png_safe_execute(image, png_write_image_16bit, display);
+      else
+         result = png_safe_execute(image, png_write_image_8bit, display);
+      display->local_row = NULL;
+
+      png_free(png_ptr, row);
+
+      /* Skip the 'write_end' on error: */
+      if (result == 0)
+         return 0;
+   }
+
+   /* Otherwise this is the case where the input is in a format currently
+    * supported by the rest of the libpng write code; call it directly.
+    */
+   else
+   {
+      png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
+      ptrdiff_t row_bytes = display->row_bytes;
+      png_uint_32 y = image->height;
+
+      for (; y > 0; --y)
+      {
+         png_write_row(png_ptr, row);
+         row += row_bytes;
+      }
+   }
+
+   png_write_end(png_ptr, info_ptr);
+   return 1;
+}
+
+
+static void (PNGCBAPI
+image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data,
+    png_size_t size)
+{
+   png_image_write_control *display = png_voidcast(png_image_write_control*,
+       png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/);
+   const png_alloc_size_t ob = display->output_bytes;
+
+   /* Check for overflow; this should never happen: */
+   if (size <= ((png_alloc_size_t)-1) - ob)
+   {
+      /* I don't think libpng ever does this, but just in case: */
+      if (size > 0)
+      {
+         if (display->memory_bytes >= ob+size) /* writing */
+            memcpy(display->memory+ob, data, size);
+
+         /* Always update the size: */
+         display->output_bytes = ob+size;
+      }
+   }
+
+   else
+      png_error(png_ptr, "png_image_write_to_memory: PNG too big");
+}
+
+static void (PNGCBAPI
+image_memory_flush)(png_structp png_ptr)
+{
+   PNG_UNUSED(png_ptr)
+}
+
+static int
+png_image_write_memory(png_voidp argument)
+{
+   png_image_write_control *display = png_voidcast(png_image_write_control*,
+       argument);
+
+   /* The rest of the memory-specific init and write_main in an error protected
+    * environment.  This case needs to use callbacks for the write operations
+    * since libpng has no built in support for writing to memory.
+    */
+   png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/,
+       image_memory_write, image_memory_flush);
+
+   return png_image_write_main(display);
+}
+
+int PNGAPI
+png_image_write_to_memory(png_imagep image, void *memory,
+    png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit,
+    const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+   /* Write the image to the given buffer, or count the bytes if it is NULL */
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      if (memory_bytes != NULL && buffer != NULL)
+      {
+         /* This is to give the caller an easier error detection in the NULL
+          * case and guard against uninitialized variable problems:
+          */
+         if (memory == NULL)
+            *memory_bytes = 0;
+
+         if (png_image_write_init(image) != 0)
+         {
+            png_image_write_control display;
+            int result;
+
+            memset(&display, 0, (sizeof display));
+            display.image = image;
+            display.buffer = buffer;
+            display.row_stride = row_stride;
+            display.colormap = colormap;
+            display.convert_to_8bit = convert_to_8bit;
+            display.memory = png_voidcast(png_bytep, memory);
+            display.memory_bytes = *memory_bytes;
+            display.output_bytes = 0;
+
+            result = png_safe_execute(image, png_image_write_memory, &display);
+            png_image_free(image);
+
+            /* write_memory returns true even if we ran out of buffer. */
+            if (result)
+            {
+               /* On out-of-buffer this function returns '0' but still updates
+                * memory_bytes:
+                */
+               if (memory != NULL && display.output_bytes > *memory_bytes)
+                  result = 0;
+
+               *memory_bytes = display.output_bytes;
+            }
+
+            return result;
+         }
+
+         else
+            return 0;
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_write_to_memory: invalid argument");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION");
+
+   else
+      return 0;
+}
+
+#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+int PNGAPI
+png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
+    const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+   /* Write the image to the given (FILE*). */
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      if (file != NULL && buffer != NULL)
+      {
+         if (png_image_write_init(image) != 0)
+         {
+            png_image_write_control display;
+            int result;
+
+            /* This is slightly evil, but png_init_io doesn't do anything other
+             * than this and we haven't changed the standard IO functions so
+             * this saves a 'safe' function.
+             */
+            image->opaque->png_ptr->io_ptr = file;
+
+            memset(&display, 0, (sizeof display));
+            display.image = image;
+            display.buffer = buffer;
+            display.row_stride = row_stride;
+            display.colormap = colormap;
+            display.convert_to_8bit = convert_to_8bit;
+
+            result = png_safe_execute(image, png_image_write_main, &display);
+            png_image_free(image);
+            return result;
+         }
+
+         else
+            return 0;
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_write_to_stdio: invalid argument");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
+   else
+      return 0;
+}
+
+int PNGAPI
+png_image_write_to_file(png_imagep image, const char *file_name,
+    int convert_to_8bit, const void *buffer, png_int_32 row_stride,
+    const void *colormap)
+{
+   /* Write the image to the named file. */
+   if (image != NULL && image->version == PNG_IMAGE_VERSION)
+   {
+      if (file_name != NULL && buffer != NULL)
+      {
+         FILE *fp = fopen(file_name, "wb");
+
+         if (fp != NULL)
+         {
+            if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
+                row_stride, colormap) != 0)
+            {
+               int error; /* from fflush/fclose */
+
+               /* Make sure the file is flushed correctly. */
+               if (fflush(fp) == 0 && ferror(fp) == 0)
+               {
+                  if (fclose(fp) == 0)
+                     return 1;
+
+                  error = errno; /* from fclose */
+               }
+
+               else
+               {
+                  error = errno; /* from fflush or ferror */
+                  (void)fclose(fp);
+               }
+
+               (void)remove(file_name);
+               /* The image has already been cleaned up; this is just used to
+                * set the error (because the original write succeeded).
+                */
+               return png_image_error(image, strerror(error));
+            }
+
+            else
+            {
+               /* Clean up: just the opened file. */
+               (void)fclose(fp);
+               (void)remove(file_name);
+               return 0;
+            }
+         }
+
+         else
+            return png_image_error(image, strerror(errno));
+      }
+
+      else
+         return png_image_error(image,
+             "png_image_write_to_file: invalid argument");
+   }
+
+   else if (image != NULL)
+      return png_image_error(image,
+          "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
+   else
+      return 0;
+}
+#endif /* SIMPLIFIED_WRITE_STDIO */
+#endif /* SIMPLIFIED_WRITE */
+#endif /* WRITE */
diff --git a/xs/src/png/libpng/pngwtran.c b/xs/src/png/libpng/pngwtran.c
new file mode 100644
index 000000000..377b43e5c
--- /dev/null
+++ b/xs/src/png/libpng/pngwtran.c
@@ -0,0 +1,576 @@
+
+/* pngwtran.c - transforms the data in a row for PNG writers
+ *
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+/* Pack pixels into bytes.  Pass the true bit depth in bit_depth.  The
+ * row_info bit depth should be 8 (one pixel per byte).  The channels
+ * should be 1 (this only happens on grayscale and paletted images).
+ */
+static void
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
+{
+   png_debug(1, "in png_do_pack");
+
+   if (row_info->bit_depth == 8 &&
+      row_info->channels == 1)
+   {
+      switch ((int)bit_depth)
+      {
+         case 1:
+         {
+            png_bytep sp, dp;
+            int mask, v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            sp = row;
+            dp = row;
+            mask = 0x80;
+            v = 0;
+
+            for (i = 0; i < row_width; i++)
+            {
+               if (*sp != 0)
+                  v |= mask;
+
+               sp++;
+
+               if (mask > 1)
+                  mask >>= 1;
+
+               else
+               {
+                  mask = 0x80;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+            }
+
+            if (mask != 0x80)
+               *dp = (png_byte)v;
+
+            break;
+         }
+
+         case 2:
+         {
+            png_bytep sp, dp;
+            unsigned int shift;
+            int v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            sp = row;
+            dp = row;
+            shift = 6;
+            v = 0;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte value;
+
+               value = (png_byte)(*sp & 0x03);
+               v |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 6;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+
+               else
+                  shift -= 2;
+
+               sp++;
+            }
+
+            if (shift != 6)
+               *dp = (png_byte)v;
+
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp, dp;
+            unsigned int shift;
+            int v;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            sp = row;
+            dp = row;
+            shift = 4;
+            v = 0;
+
+            for (i = 0; i < row_width; i++)
+            {
+               png_byte value;
+
+               value = (png_byte)(*sp & 0x0f);
+               v |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 4;
+                  *dp = (png_byte)v;
+                  dp++;
+                  v = 0;
+               }
+
+               else
+                  shift -= 4;
+
+               sp++;
+            }
+
+            if (shift != 4)
+               *dp = (png_byte)v;
+
+            break;
+         }
+
+         default:
+            break;
+      }
+
+      row_info->bit_depth = (png_byte)bit_depth;
+      row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+          row_info->width);
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+/* Shift pixel values to take advantage of whole range.  Pass the
+ * true number of bits in bit_depth.  The row should be packed
+ * according to row_info->bit_depth.  Thus, if you had a row of
+ * bit depth 4, but the pixels only had values from 0 to 7, you
+ * would pass 3 as bit_depth, and this routine would translate the
+ * data to 0 to 15.
+ */
+static void
+png_do_shift(png_row_infop row_info, png_bytep row,
+    png_const_color_8p bit_depth)
+{
+   png_debug(1, "in png_do_shift");
+
+   if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      int shift_start[4], shift_dec[4];
+      unsigned int channels = 0;
+
+      if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->red;
+         shift_dec[channels] = bit_depth->red;
+         channels++;
+
+         shift_start[channels] = row_info->bit_depth - bit_depth->green;
+         shift_dec[channels] = bit_depth->green;
+         channels++;
+
+         shift_start[channels] = row_info->bit_depth - bit_depth->blue;
+         shift_dec[channels] = bit_depth->blue;
+         channels++;
+      }
+
+      else
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->gray;
+         shift_dec[channels] = bit_depth->gray;
+         channels++;
+      }
+
+      if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
+      {
+         shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
+         shift_dec[channels] = bit_depth->alpha;
+         channels++;
+      }
+
+      /* With low row depths, could only be grayscale, so one channel */
+      if (row_info->bit_depth < 8)
+      {
+         png_bytep bp = row;
+         png_size_t i;
+         unsigned int mask;
+         png_size_t row_bytes = row_info->rowbytes;
+
+         if (bit_depth->gray == 1 && row_info->bit_depth == 2)
+            mask = 0x55;
+
+         else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
+            mask = 0x11;
+
+         else
+            mask = 0xff;
+
+         for (i = 0; i < row_bytes; i++, bp++)
+         {
+            int j;
+            unsigned int v, out;
+
+            v = *bp;
+            out = 0;
+
+            for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
+            {
+               if (j > 0)
+                  out |= v << j;
+
+               else
+                  out |= (v >> (-j)) & mask;
+            }
+
+            *bp = (png_byte)(out & 0xff);
+         }
+      }
+
+      else if (row_info->bit_depth == 8)
+      {
+         png_bytep bp = row;
+         png_uint_32 i;
+         png_uint_32 istop = channels * row_info->width;
+
+         for (i = 0; i < istop; i++, bp++)
+         {
+
+            const unsigned int c = i%channels;
+            int j;
+            unsigned int v, out;
+
+            v = *bp;
+            out = 0;
+
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+            {
+               if (j > 0)
+                  out |= v << j;
+
+               else
+                  out |= v >> (-j);
+            }
+
+            *bp = (png_byte)(out & 0xff);
+         }
+      }
+
+      else
+      {
+         png_bytep bp;
+         png_uint_32 i;
+         png_uint_32 istop = channels * row_info->width;
+
+         for (bp = row, i = 0; i < istop; i++)
+         {
+            const unsigned int c = i%channels;
+            int j;
+            unsigned int value, v;
+
+            v = png_get_uint_16(bp);
+            value = 0;
+
+            for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
+            {
+               if (j > 0)
+                  value |= v << j;
+
+               else
+                  value |= v >> (-j);
+            }
+            *bp++ = (png_byte)((value >> 8) & 0xff);
+            *bp++ = (png_byte)(value & 0xff);
+         }
+      }
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+static void
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_swap_alpha");
+
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This converts from ARGB to RGBA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This converts from AARRGGBB to RRGGBBAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This converts from AG to GA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save;
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This converts from AAGG to GGAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               png_byte save[2];
+               save[0] = *(sp++);
+               save[1] = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = save[0];
+               *(dp++) = save[1];
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+static void
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_write_invert_alpha");
+
+   {
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This inverts the alpha channel in RGBA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=3; dp = sp;
+               *dp = (png_byte)(255 - *(sp++));
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This inverts the alpha channel in RRGGBBAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=6; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp     = (png_byte)(255 - *(sp++));
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+
+      else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+            /* This inverts the alpha channel in GA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               *(dp++) = *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+            }
+         }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         else
+         {
+            /* This inverts the alpha channel in GGAA */
+            png_bytep sp, dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            for (i = 0, sp = dp = row; i < row_width; i++)
+            {
+               /* Does nothing
+               *(dp++) = *(sp++);
+               *(dp++) = *(sp++);
+               */
+               sp+=2; dp = sp;
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp     = (png_byte)(255 - *(sp++));
+            }
+         }
+#endif /* WRITE_16BIT */
+      }
+   }
+}
+#endif
+
+/* Transform the data according to the user's wishes.  The order of
+ * transformations is significant.
+ */
+void /* PRIVATE */
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
+{
+   png_debug(1, "in png_do_write_transformations");
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+      if (png_ptr->write_user_transform_fn != NULL)
+         (*(png_ptr->write_user_transform_fn)) /* User write transform
+                                                 function */
+             (png_ptr,  /* png_ptr */
+             row_info,  /* row_info: */
+                /*  png_uint_32 width;       width of row */
+                /*  png_size_t rowbytes;     number of bytes in row */
+                /*  png_byte color_type;     color type of pixels */
+                /*  png_byte bit_depth;      bit depth of samples */
+                /*  png_byte channels;       number of channels (1-4) */
+                /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
+             png_ptr->row_buf + 1);      /* start of pixel data for row */
+#endif
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+          !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
+#endif
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
+      png_do_packswap(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+   if ((png_ptr->transformations & PNG_PACK) != 0)
+      png_do_pack(row_info, png_ptr->row_buf + 1,
+          (png_uint_32)png_ptr->bit_depth);
+#endif
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+#  ifdef PNG_16BIT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
+      png_do_swap(row_info, png_ptr->row_buf + 1);
+#  endif
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
+      png_do_shift(row_info, png_ptr->row_buf + 1,
+           &(png_ptr->shift));
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
+      png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
+      png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
+   if ((png_ptr->transformations & PNG_BGR) != 0)
+      png_do_bgr(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
+      png_do_invert(row_info, png_ptr->row_buf + 1);
+#endif
+}
+#endif /* WRITE_TRANSFORMS */
+#endif /* WRITE */
diff --git a/xs/src/png/libpng/pngwutil.c b/xs/src/png/libpng/pngwutil.c
new file mode 100644
index 000000000..0d4fb1336
--- /dev/null
+++ b/xs/src/png/libpng/pngwutil.c
@@ -0,0 +1,2784 @@
+
+/* pngwutil.c - utilities to write a PNG file
+ *
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+
+#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+/* Place a 32-bit number into a buffer in PNG byte order.  We work
+ * with unsigned numbers for convenience, although one supported
+ * ancillary chunk uses signed (two's complement) numbers.
+ */
+void PNGAPI
+png_save_uint_32(png_bytep buf, png_uint_32 i)
+{
+   buf[0] = (png_byte)((i >> 24) & 0xffU);
+   buf[1] = (png_byte)((i >> 16) & 0xffU);
+   buf[2] = (png_byte)((i >>  8) & 0xffU);
+   buf[3] = (png_byte)( i        & 0xffU);
+}
+
+/* Place a 16-bit number into a buffer in PNG byte order.
+ * The parameter is declared unsigned int, not png_uint_16,
+ * just to avoid potential problems on pre-ANSI C compilers.
+ */
+void PNGAPI
+png_save_uint_16(png_bytep buf, unsigned int i)
+{
+   buf[0] = (png_byte)((i >> 8) & 0xffU);
+   buf[1] = (png_byte)( i       & 0xffU);
+}
+#endif
+
+/* Simple function to write the signature.  If we have already written
+ * the magic bytes of the signature, or more likely, the PNG stream is
+ * being embedded into another stream and doesn't need its own signature,
+ * we should call png_set_sig_bytes() to tell libpng how many of the
+ * bytes have already been written.
+ */
+void PNGAPI
+png_write_sig(png_structrp png_ptr)
+{
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that the signature is being written */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
+#endif
+
+   /* Write the rest of the 8 byte signature */
+   png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
+       (png_size_t)(8 - png_ptr->sig_bytes));
+
+   if (png_ptr->sig_bytes < 3)
+      png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
+/* Write the start of a PNG chunk.  The type is the chunk type.
+ * The total_length is the sum of the lengths of all the data you will be
+ * passing in png_write_chunk_data().
+ */
+static void
+png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
+    png_uint_32 length)
+{
+   png_byte buf[8];
+
+#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
+   PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
+   png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
+#endif
+
+   if (png_ptr == NULL)
+      return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that the chunk header is being written.
+    * PNG_IO_CHUNK_HDR requires a single I/O call.
+    */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
+#endif
+
+   /* Write the length and the chunk name */
+   png_save_uint_32(buf, length);
+   png_save_uint_32(buf + 4, chunk_name);
+   png_write_data(png_ptr, buf, 8);
+
+   /* Put the chunk name into png_ptr->chunk_name */
+   png_ptr->chunk_name = chunk_name;
+
+   /* Reset the crc and run it over the chunk name */
+   png_reset_crc(png_ptr);
+
+   png_calculate_crc(png_ptr, buf + 4, 4);
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that chunk data will (possibly) be written.
+    * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
+    */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
+#endif
+}
+
+void PNGAPI
+png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
+    png_uint_32 length)
+{
+   png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
+}
+
+/* Write the data of a PNG chunk started with png_write_chunk_header().
+ * Note that multiple calls to this function are allowed, and that the
+ * sum of the lengths from these calls *must* add up to the total_length
+ * given to png_write_chunk_header().
+ */
+void PNGAPI
+png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
+    png_size_t length)
+{
+   /* Write the data, and run the CRC over it */
+   if (png_ptr == NULL)
+      return;
+
+   if (data != NULL && length > 0)
+   {
+      png_write_data(png_ptr, data, length);
+
+      /* Update the CRC after writing the data,
+       * in case the user I/O routine alters it.
+       */
+      png_calculate_crc(png_ptr, data, length);
+   }
+}
+
+/* Finish a chunk started with png_write_chunk_header(). */
+void PNGAPI
+png_write_chunk_end(png_structrp png_ptr)
+{
+   png_byte buf[4];
+
+   if (png_ptr == NULL) return;
+
+#ifdef PNG_IO_STATE_SUPPORTED
+   /* Inform the I/O callback that the chunk CRC is being written.
+    * PNG_IO_CHUNK_CRC requires a single I/O function call.
+    */
+   png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
+#endif
+
+   /* Write the crc in a single operation */
+   png_save_uint_32(buf, png_ptr->crc);
+
+   png_write_data(png_ptr, buf, (png_size_t)4);
+}
+
+/* Write a PNG chunk all at once.  The type is an array of ASCII characters
+ * representing the chunk name.  The array must be at least 4 bytes in
+ * length, and does not need to be null terminated.  To be safe, pass the
+ * pre-defined chunk names here, and if you need a new one, define it
+ * where the others are defined.  The length is the length of the data.
+ * All the data must be present.  If that is not possible, use the
+ * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
+ * functions instead.
+ */
+static void
+png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
+    png_const_bytep data, png_size_t length)
+{
+   if (png_ptr == NULL)
+      return;
+
+   /* On 64-bit architectures 'length' may not fit in a png_uint_32. */
+   if (length > PNG_UINT_31_MAX)
+      png_error(png_ptr, "length exceeds PNG maximum");
+
+   png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+   png_write_chunk_data(png_ptr, data, length);
+   png_write_chunk_end(png_ptr);
+}
+
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
+    png_const_bytep data, png_size_t length)
+{
+   png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+       length);
+}
+
+/* This is used below to find the size of an image to pass to png_deflate_claim,
+ * so it only needs to be accurate if the size is less than 16384 bytes (the
+ * point at which a lower LZ window size can be used.)
+ */
+static png_alloc_size_t
+png_image_size(png_structrp png_ptr)
+{
+   /* Only return sizes up to the maximum of a png_uint_32; do this by limiting
+    * the width and height used to 15 bits.
+    */
+   png_uint_32 h = png_ptr->height;
+
+   if (png_ptr->rowbytes < 32768 && h < 32768)
+   {
+      if (png_ptr->interlaced != 0)
+      {
+         /* Interlacing makes the image larger because of the replication of
+          * both the filter byte and the padding to a byte boundary.
+          */
+         png_uint_32 w = png_ptr->width;
+         unsigned int pd = png_ptr->pixel_depth;
+         png_alloc_size_t cb_base;
+         int pass;
+
+         for (cb_base=0, pass=0; pass<=6; ++pass)
+         {
+            png_uint_32 pw = PNG_PASS_COLS(w, pass);
+
+            if (pw > 0)
+               cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
+         }
+
+         return cb_base;
+      }
+
+      else
+         return (png_ptr->rowbytes+1) * h;
+   }
+
+   else
+      return 0xffffffffU;
+}
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+   /* This is the code to hack the first two bytes of the deflate stream (the
+    * deflate header) to correct the windowBits value to match the actual data
+    * size.  Note that the second argument is the *uncompressed* size but the
+    * first argument is the *compressed* data (and it must be deflate
+    * compressed.)
+    */
+static void
+optimize_cmf(png_bytep data, png_alloc_size_t data_size)
+{
+   /* Optimize the CMF field in the zlib stream.  The resultant zlib stream is
+    * still compliant to the stream specification.
+    */
+   if (data_size <= 16384) /* else windowBits must be 15 */
+   {
+      unsigned int z_cmf = data[0];  /* zlib compression method and flags */
+
+      if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+      {
+         unsigned int z_cinfo;
+         unsigned int half_z_window_size;
+
+         z_cinfo = z_cmf >> 4;
+         half_z_window_size = 1U << (z_cinfo + 7);
+
+         if (data_size <= half_z_window_size) /* else no change */
+         {
+            unsigned int tmp;
+
+            do
+            {
+               half_z_window_size >>= 1;
+               --z_cinfo;
+            }
+            while (z_cinfo > 0 && data_size <= half_z_window_size);
+
+            z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+
+            data[0] = (png_byte)z_cmf;
+            tmp = data[1] & 0xe0;
+            tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+            data[1] = (png_byte)tmp;
+         }
+      }
+   }
+}
+#endif /* WRITE_OPTIMIZE_CMF */
+
+/* Initialize the compressor for the appropriate type of compression. */
+static int
+png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
+    png_alloc_size_t data_size)
+{
+   if (png_ptr->zowner != 0)
+   {
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+      char msg[64];
+
+      PNG_STRING_FROM_CHUNK(msg, owner);
+      msg[4] = ':';
+      msg[5] = ' ';
+      PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
+      /* So the message that results is "<chunk> using zstream"; this is an
+       * internal error, but is very useful for debugging.  i18n requirements
+       * are minimal.
+       */
+      (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
+#endif
+#if PNG_RELEASE_BUILD
+         png_warning(png_ptr, msg);
+
+         /* Attempt sane error recovery */
+         if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
+         {
+            png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
+            return Z_STREAM_ERROR;
+         }
+
+         png_ptr->zowner = 0;
+#else
+         png_error(png_ptr, msg);
+#endif
+   }
+
+   {
+      int level = png_ptr->zlib_level;
+      int method = png_ptr->zlib_method;
+      int windowBits = png_ptr->zlib_window_bits;
+      int memLevel = png_ptr->zlib_mem_level;
+      int strategy; /* set below */
+      int ret; /* zlib return code */
+
+      if (owner == png_IDAT)
+      {
+         if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0)
+            strategy = png_ptr->zlib_strategy;
+
+         else if (png_ptr->do_filter != PNG_FILTER_NONE)
+            strategy = PNG_Z_DEFAULT_STRATEGY;
+
+         else
+            strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
+      }
+
+      else
+      {
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+            level = png_ptr->zlib_text_level;
+            method = png_ptr->zlib_text_method;
+            windowBits = png_ptr->zlib_text_window_bits;
+            memLevel = png_ptr->zlib_text_mem_level;
+            strategy = png_ptr->zlib_text_strategy;
+#else
+            /* If customization is not supported the values all come from the
+             * IDAT values except for the strategy, which is fixed to the
+             * default.  (This is the pre-1.6.0 behavior too, although it was
+             * implemented in a very different way.)
+             */
+            strategy = Z_DEFAULT_STRATEGY;
+#endif
+      }
+
+      /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
+       * happening just pass 32768 as the data_size parameter.  Notice that zlib
+       * requires an extra 262 bytes in the window in addition to the data to be
+       * able to see the whole of the data, so if data_size+262 takes us to the
+       * next windowBits size we need to fix up the value later.  (Because even
+       * though deflate needs the extra window, inflate does not!)
+       */
+      if (data_size <= 16384)
+      {
+         /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
+          * work round a Microsoft Visual C misbehavior which, contrary to C-90,
+          * widens the result of the following shift to 64-bits if (and,
+          * apparently, only if) it is used in a test.
+          */
+         unsigned int half_window_size = 1U << (windowBits-1);
+
+         while (data_size + 262 <= half_window_size)
+         {
+            half_window_size >>= 1;
+            --windowBits;
+         }
+      }
+
+      /* Check against the previous initialized values, if any. */
+      if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 &&
+         (png_ptr->zlib_set_level != level ||
+         png_ptr->zlib_set_method != method ||
+         png_ptr->zlib_set_window_bits != windowBits ||
+         png_ptr->zlib_set_mem_level != memLevel ||
+         png_ptr->zlib_set_strategy != strategy))
+      {
+         if (deflateEnd(&png_ptr->zstream) != Z_OK)
+            png_warning(png_ptr, "deflateEnd failed (ignored)");
+
+         png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
+      }
+
+      /* For safety clear out the input and output pointers (currently zlib
+       * doesn't use them on Init, but it might in the future).
+       */
+      png_ptr->zstream.next_in = NULL;
+      png_ptr->zstream.avail_in = 0;
+      png_ptr->zstream.next_out = NULL;
+      png_ptr->zstream.avail_out = 0;
+
+      /* Now initialize if required, setting the new parameters, otherwise just
+       * do a simple reset to the previous parameters.
+       */
+      if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
+         ret = deflateReset(&png_ptr->zstream);
+
+      else
+      {
+         ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
+             memLevel, strategy);
+
+         if (ret == Z_OK)
+            png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
+      }
+
+      /* The return code is from either deflateReset or deflateInit2; they have
+       * pretty much the same set of error codes.
+       */
+      if (ret == Z_OK)
+         png_ptr->zowner = owner;
+
+      else
+         png_zstream_error(png_ptr, ret);
+
+      return ret;
+   }
+}
+
+/* Clean up (or trim) a linked list of compression buffers. */
+void /* PRIVATE */
+png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
+{
+   png_compression_bufferp list = *listp;
+
+   if (list != NULL)
+   {
+      *listp = NULL;
+
+      do
+      {
+         png_compression_bufferp next = list->next;
+
+         png_free(png_ptr, list);
+         list = next;
+      }
+      while (list != NULL);
+   }
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller to allow access to the relevant local variables.
+ *
+ * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
+ * temporary buffers.  From 1.6.0 it is retained in png_struct so that it will
+ * be correctly freed in the event of a write error (previous implementations
+ * just leaked memory.)
+ */
+typedef struct
+{
+   png_const_bytep      input;        /* The uncompressed input data */
+   png_alloc_size_t     input_len;    /* Its length */
+   png_uint_32          output_len;   /* Final compressed length */
+   png_byte             output[1024]; /* First block of output */
+} compression_state;
+
+static void
+png_text_compress_init(compression_state *comp, png_const_bytep input,
+    png_alloc_size_t input_len)
+{
+   comp->input = input;
+   comp->input_len = input_len;
+   comp->output_len = 0;
+}
+
+/* Compress the data in the compression state input */
+static int
+png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
+    compression_state *comp, png_uint_32 prefix_len)
+{
+   int ret;
+
+   /* To find the length of the output it is necessary to first compress the
+    * input. The result is buffered rather than using the two-pass algorithm
+    * that is used on the inflate side; deflate is assumed to be slower and a
+    * PNG writer is assumed to have more memory available than a PNG reader.
+    *
+    * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
+    * upper limit on the output size, but it is always bigger than the input
+    * size so it is likely to be more efficient to use this linked-list
+    * approach.
+    */
+   ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
+
+   if (ret != Z_OK)
+      return ret;
+
+   /* Set up the compression buffers, we need a loop here to avoid overflowing a
+    * uInt.  Use ZLIB_IO_MAX to limit the input.  The output is always limited
+    * by the output buffer size, so there is no need to check that.  Since this
+    * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
+    * in size.
+    */
+   {
+      png_compression_bufferp *end = &png_ptr->zbuffer_list;
+      png_alloc_size_t input_len = comp->input_len; /* may be zero! */
+      png_uint_32 output_len;
+
+      /* zlib updates these for us: */
+      png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
+      png_ptr->zstream.avail_in = 0; /* Set below */
+      png_ptr->zstream.next_out = comp->output;
+      png_ptr->zstream.avail_out = (sizeof comp->output);
+
+      output_len = png_ptr->zstream.avail_out;
+
+      do
+      {
+         uInt avail_in = ZLIB_IO_MAX;
+
+         if (avail_in > input_len)
+            avail_in = (uInt)input_len;
+
+         input_len -= avail_in;
+
+         png_ptr->zstream.avail_in = avail_in;
+
+         if (png_ptr->zstream.avail_out == 0)
+         {
+            png_compression_buffer *next;
+
+            /* Chunk data is limited to 2^31 bytes in length, so the prefix
+             * length must be counted here.
+             */
+            if (output_len + prefix_len > PNG_UINT_31_MAX)
+            {
+               ret = Z_MEM_ERROR;
+               break;
+            }
+
+            /* Need a new (malloc'ed) buffer, but there may be one present
+             * already.
+             */
+            next = *end;
+            if (next == NULL)
+            {
+               next = png_voidcast(png_compression_bufferp, png_malloc_base
+                  (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+
+               if (next == NULL)
+               {
+                  ret = Z_MEM_ERROR;
+                  break;
+               }
+
+               /* Link in this buffer (so that it will be freed later) */
+               next->next = NULL;
+               *end = next;
+            }
+
+            png_ptr->zstream.next_out = next->output;
+            png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+            output_len += png_ptr->zstream.avail_out;
+
+            /* Move 'end' to the next buffer pointer. */
+            end = &next->next;
+         }
+
+         /* Compress the data */
+         ret = deflate(&png_ptr->zstream,
+             input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
+
+         /* Claw back input data that was not consumed (because avail_in is
+          * reset above every time round the loop).
+          */
+         input_len += png_ptr->zstream.avail_in;
+         png_ptr->zstream.avail_in = 0; /* safety */
+      }
+      while (ret == Z_OK);
+
+      /* There may be some space left in the last output buffer. This needs to
+       * be subtracted from output_len.
+       */
+      output_len -= png_ptr->zstream.avail_out;
+      png_ptr->zstream.avail_out = 0; /* safety */
+      comp->output_len = output_len;
+
+      /* Now double check the output length, put in a custom message if it is
+       * too long.  Otherwise ensure the z_stream::msg pointer is set to
+       * something.
+       */
+      if (output_len + prefix_len >= PNG_UINT_31_MAX)
+      {
+         png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
+         ret = Z_MEM_ERROR;
+      }
+
+      else
+         png_zstream_error(png_ptr, ret);
+
+      /* Reset zlib for another zTXt/iTXt or image data */
+      png_ptr->zowner = 0;
+
+      /* The only success case is Z_STREAM_END, input_len must be 0; if not this
+       * is an internal error.
+       */
+      if (ret == Z_STREAM_END && input_len == 0)
+      {
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+         /* Fix up the deflate header, if required */
+         optimize_cmf(comp->output, comp->input_len);
+#endif
+         /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
+          * function above to return Z_STREAM_END on an error (though it never
+          * does in the current versions of zlib.)
+          */
+         return Z_OK;
+      }
+
+      else
+         return ret;
+   }
+}
+
+/* Ship the compressed text out via chunk writes */
+static void
+png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
+{
+   png_uint_32 output_len = comp->output_len;
+   png_const_bytep output = comp->output;
+   png_uint_32 avail = (sizeof comp->output);
+   png_compression_buffer *next = png_ptr->zbuffer_list;
+
+   for (;;)
+   {
+      if (avail > output_len)
+         avail = output_len;
+
+      png_write_chunk_data(png_ptr, output, avail);
+
+      output_len -= avail;
+
+      if (output_len == 0 || next == NULL)
+         break;
+
+      avail = png_ptr->zbuffer_size;
+      output = next->output;
+      next = next->next;
+   }
+
+   /* This is an internal error; 'next' must have been NULL! */
+   if (output_len > 0)
+      png_error(png_ptr, "error writing ancillary chunked compressed data");
+}
+#endif /* WRITE_COMPRESSED_TEXT */
+
+/* Write the IHDR chunk, and update the png_struct with the necessary
+ * information.  Note that the rest of this code depends upon this
+ * information being correct.
+ */
+void /* PRIVATE */
+png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
+    int bit_depth, int color_type, int compression_type, int filter_type,
+    int interlace_type)
+{
+   png_byte buf[13]; /* Buffer to store the IHDR info */
+   int is_invalid_depth;
+
+   png_debug(1, "in png_write_IHDR");
+
+   /* Check that we have valid input data from the application info */
+   switch (color_type)
+   {
+      case PNG_COLOR_TYPE_GRAY:
+         switch (bit_depth)
+         {
+            case 1:
+            case 2:
+            case 4:
+            case 8:
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+            case 16:
+#endif
+               png_ptr->channels = 1; break;
+
+            default:
+               png_error(png_ptr,
+                   "Invalid bit depth for grayscale image");
+         }
+         break;
+
+      case PNG_COLOR_TYPE_RGB:
+         is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+         if (is_invalid_depth)
+            png_error(png_ptr, "Invalid bit depth for RGB image");
+
+         png_ptr->channels = 3;
+         break;
+
+      case PNG_COLOR_TYPE_PALETTE:
+         switch (bit_depth)
+         {
+            case 1:
+            case 2:
+            case 4:
+            case 8:
+               png_ptr->channels = 1;
+               break;
+
+            default:
+               png_error(png_ptr, "Invalid bit depth for paletted image");
+         }
+         break;
+
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+         if (is_invalid_depth)
+            png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
+
+         png_ptr->channels = 2;
+         break;
+
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+         is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+         if (is_invalid_depth)
+            png_error(png_ptr, "Invalid bit depth for RGBA image");
+
+         png_ptr->channels = 4;
+         break;
+
+      default:
+         png_error(png_ptr, "Invalid image color type specified");
+   }
+
+   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Invalid compression type specified");
+      compression_type = PNG_COMPRESSION_TYPE_BASE;
+   }
+
+   /* Write filter_method 64 (intrapixel differencing) only if
+    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
+    * 2. Libpng did not write a PNG signature (this filter_method is only
+    *    used in PNG datastreams that are embedded in MNG datastreams) and
+    * 3. The application called png_permit_mng_features with a mask that
+    *    included PNG_FLAG_MNG_FILTER_64 and
+    * 4. The filter_method is 64 and
+    * 5. The color_type is RGB or RGBA
+    */
+   if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+       !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
+       ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
+       (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
+       (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
+#endif
+       filter_type != PNG_FILTER_TYPE_BASE)
+   {
+      png_warning(png_ptr, "Invalid filter type specified");
+      filter_type = PNG_FILTER_TYPE_BASE;
+   }
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   if (interlace_type != PNG_INTERLACE_NONE &&
+       interlace_type != PNG_INTERLACE_ADAM7)
+   {
+      png_warning(png_ptr, "Invalid interlace type specified");
+      interlace_type = PNG_INTERLACE_ADAM7;
+   }
+#else
+   interlace_type=PNG_INTERLACE_NONE;
+#endif
+
+   /* Save the relevant information */
+   png_ptr->bit_depth = (png_byte)bit_depth;
+   png_ptr->color_type = (png_byte)color_type;
+   png_ptr->interlaced = (png_byte)interlace_type;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+   png_ptr->filter_type = (png_byte)filter_type;
+#endif
+   png_ptr->compression_type = (png_byte)compression_type;
+   png_ptr->width = width;
+   png_ptr->height = height;
+
+   png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
+   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
+   /* Set the usr info, so any transformations can modify it */
+   png_ptr->usr_width = png_ptr->width;
+   png_ptr->usr_bit_depth = png_ptr->bit_depth;
+   png_ptr->usr_channels = png_ptr->channels;
+
+   /* Pack the header information into the buffer */
+   png_save_uint_32(buf, width);
+   png_save_uint_32(buf + 4, height);
+   buf[8] = (png_byte)bit_depth;
+   buf[9] = (png_byte)color_type;
+   buf[10] = (png_byte)compression_type;
+   buf[11] = (png_byte)filter_type;
+   buf[12] = (png_byte)interlace_type;
+
+   /* Write the chunk */
+   png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
+
+   if ((png_ptr->do_filter) == PNG_NO_FILTERS)
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
+          png_ptr->bit_depth < 8)
+         png_ptr->do_filter = PNG_FILTER_NONE;
+
+      else
+         png_ptr->do_filter = PNG_ALL_FILTERS;
+   }
+
+   png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
+}
+
+/* Write the palette.  We are careful not to trust png_color to be in the
+ * correct order for PNG, so people can redefine it to any convenient
+ * structure.
+ */
+void /* PRIVATE */
+png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
+    png_uint_32 num_pal)
+{
+   png_uint_32 max_palette_length, i;
+   png_const_colorp pal_ptr;
+   png_byte buf[3];
+
+   png_debug(1, "in png_write_PLTE");
+
+   max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+      (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
+   if ((
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+       (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 &&
+#endif
+       num_pal == 0) || num_pal > max_palette_length)
+   {
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      {
+         png_error(png_ptr, "Invalid number of colors in palette");
+      }
+
+      else
+      {
+         png_warning(png_ptr, "Invalid number of colors in palette");
+         return;
+      }
+   }
+
+   if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
+   {
+      png_warning(png_ptr,
+          "Ignoring request to write a PLTE chunk in grayscale PNG");
+
+      return;
+   }
+
+   png_ptr->num_palette = (png_uint_16)num_pal;
+   png_debug1(3, "num_palette = %d", png_ptr->num_palette);
+
+   png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+
+   for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
+   {
+      buf[0] = pal_ptr->red;
+      buf[1] = pal_ptr->green;
+      buf[2] = pal_ptr->blue;
+      png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+   }
+
+#else
+   /* This is a little slower but some buggy compilers need to do this
+    * instead
+    */
+   pal_ptr=palette;
+
+   for (i = 0; i < num_pal; i++)
+   {
+      buf[0] = pal_ptr[i].red;
+      buf[1] = pal_ptr[i].green;
+      buf[2] = pal_ptr[i].blue;
+      png_write_chunk_data(png_ptr, buf, (png_size_t)3);
+   }
+
+#endif
+   png_write_chunk_end(png_ptr);
+   png_ptr->mode |= PNG_HAVE_PLTE;
+}
+
+/* This is similar to png_text_compress, above, except that it does not require
+ * all of the data at once and, instead of buffering the compressed result,
+ * writes it as IDAT chunks.  Unlike png_text_compress it *can* png_error out
+ * because it calls the write interface.  As a result it does its own error
+ * reporting and does not return an error code.  In the event of error it will
+ * just call png_error.  The input data length may exceed 32-bits.  The 'flush'
+ * parameter is exactly the same as that to deflate, with the following
+ * meanings:
+ *
+ * Z_NO_FLUSH: normal incremental output of compressed data
+ * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
+ * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
+ *
+ * The routine manages the acquire and release of the png_ptr->zstream by
+ * checking and (at the end) clearing png_ptr->zowner; it does some sanity
+ * checks on the 'mode' flags while doing this.
+ */
+void /* PRIVATE */
+png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
+    png_alloc_size_t input_len, int flush)
+{
+   if (png_ptr->zowner != png_IDAT)
+   {
+      /* First time.   Ensure we have a temporary buffer for compression and
+       * trim the buffer list if it has more than one entry to free memory.
+       * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
+       * created at this point, but the check here is quick and safe.
+       */
+      if (png_ptr->zbuffer_list == NULL)
+      {
+         png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
+             png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
+         png_ptr->zbuffer_list->next = NULL;
+      }
+
+      else
+         png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
+
+      /* It is a terminal error if we can't claim the zstream. */
+      if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
+         png_error(png_ptr, png_ptr->zstream.msg);
+
+      /* The output state is maintained in png_ptr->zstream, so it must be
+       * initialized here after the claim.
+       */
+      png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
+      png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
+   }
+
+   /* Now loop reading and writing until all the input is consumed or an error
+    * terminates the operation.  The _out values are maintained across calls to
+    * this function, but the input must be reset each time.
+    */
+   png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
+   png_ptr->zstream.avail_in = 0; /* set below */
+   for (;;)
+   {
+      int ret;
+
+      /* INPUT: from the row data */
+      uInt avail = ZLIB_IO_MAX;
+
+      if (avail > input_len)
+         avail = (uInt)input_len; /* safe because of the check */
+
+      png_ptr->zstream.avail_in = avail;
+      input_len -= avail;
+
+      ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
+
+      /* Include as-yet unconsumed input */
+      input_len += png_ptr->zstream.avail_in;
+      png_ptr->zstream.avail_in = 0;
+
+      /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note
+       * that these two zstream fields are preserved across the calls, therefore
+       * there is no need to set these up on entry to the loop.
+       */
+      if (png_ptr->zstream.avail_out == 0)
+      {
+         png_bytep data = png_ptr->zbuffer_list->output;
+         uInt size = png_ptr->zbuffer_size;
+
+         /* Write an IDAT containing the data then reset the buffer.  The
+          * first IDAT may need deflate header optimization.
+          */
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+            if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+                png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+               optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+         if (size > 0)
+            png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+         png_ptr->mode |= PNG_HAVE_IDAT;
+
+         png_ptr->zstream.next_out = data;
+         png_ptr->zstream.avail_out = size;
+
+         /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
+          * the same flush parameter until it has finished output, for NO_FLUSH
+          * it doesn't matter.
+          */
+         if (ret == Z_OK && flush != Z_NO_FLUSH)
+            continue;
+      }
+
+      /* The order of these checks doesn't matter much; it just affects which
+       * possible error might be detected if multiple things go wrong at once.
+       */
+      if (ret == Z_OK) /* most likely return code! */
+      {
+         /* If all the input has been consumed then just return.  If Z_FINISH
+          * was used as the flush parameter something has gone wrong if we get
+          * here.
+          */
+         if (input_len == 0)
+         {
+            if (flush == Z_FINISH)
+               png_error(png_ptr, "Z_OK on Z_FINISH with output space");
+
+            return;
+         }
+      }
+
+      else if (ret == Z_STREAM_END && flush == Z_FINISH)
+      {
+         /* This is the end of the IDAT data; any pending output must be
+          * flushed.  For small PNG files we may still be at the beginning.
+          */
+         png_bytep data = png_ptr->zbuffer_list->output;
+         uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
+
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+         if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 &&
+             png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
+            optimize_cmf(data, png_image_size(png_ptr));
+#endif
+
+         if (size > 0)
+            png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+         png_ptr->zstream.avail_out = 0;
+         png_ptr->zstream.next_out = NULL;
+         png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
+
+         png_ptr->zowner = 0; /* Release the stream */
+         return;
+      }
+
+      else
+      {
+         /* This is an error condition. */
+         png_zstream_error(png_ptr, ret);
+         png_error(png_ptr, png_ptr->zstream.msg);
+      }
+   }
+}
+
+/* Write an IEND chunk */
+void /* PRIVATE */
+png_write_IEND(png_structrp png_ptr)
+{
+   png_debug(1, "in png_write_IEND");
+
+   png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
+   png_ptr->mode |= PNG_HAVE_IEND;
+}
+
+#ifdef PNG_WRITE_gAMA_SUPPORTED
+/* Write a gAMA chunk */
+void /* PRIVATE */
+png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
+{
+   png_byte buf[4];
+
+   png_debug(1, "in png_write_gAMA");
+
+   /* file_gamma is saved in 1/100,000ths */
+   png_save_uint_32(buf, (png_uint_32)file_gamma);
+   png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
+}
+#endif
+
+#ifdef PNG_WRITE_sRGB_SUPPORTED
+/* Write a sRGB chunk */
+void /* PRIVATE */
+png_write_sRGB(png_structrp png_ptr, int srgb_intent)
+{
+   png_byte buf[1];
+
+   png_debug(1, "in png_write_sRGB");
+
+   if (srgb_intent >= PNG_sRGB_INTENT_LAST)
+      png_warning(png_ptr,
+          "Invalid sRGB rendering intent specified");
+
+   buf[0]=(png_byte)srgb_intent;
+   png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
+}
+#endif
+
+#ifdef PNG_WRITE_iCCP_SUPPORTED
+/* Write an iCCP chunk */
+void /* PRIVATE */
+png_write_iCCP(png_structrp png_ptr, png_const_charp name,
+    png_const_bytep profile)
+{
+   png_uint_32 name_len;
+   png_uint_32 profile_len;
+   png_byte new_name[81]; /* 1 byte for the compression byte */
+   compression_state comp;
+   png_uint_32 temp;
+
+   png_debug(1, "in png_write_iCCP");
+
+   /* These are all internal problems: the profile should have been checked
+    * before when it was stored.
+    */
+   if (profile == NULL)
+      png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
+
+   profile_len = png_get_uint_32(profile);
+
+   if (profile_len < 132)
+      png_error(png_ptr, "ICC profile too short");
+
+   temp = (png_uint_32) (*(profile+8));
+   if (temp > 3 && (profile_len & 0x03))
+      png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
+
+   {
+      png_uint_32 embedded_profile_len = png_get_uint_32(profile);
+
+      if (profile_len != embedded_profile_len)
+         png_error(png_ptr, "Profile length does not match profile");
+   }
+
+   name_len = png_check_keyword(png_ptr, name, new_name);
+
+   if (name_len == 0)
+      png_error(png_ptr, "iCCP: invalid keyword");
+
+   new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
+
+   /* Make sure we include the NULL after the name and the compression type */
+   ++name_len;
+
+   png_text_compress_init(&comp, profile, profile_len);
+
+   /* Allow for keyword terminator and compression byte */
+   if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
+      png_error(png_ptr, png_ptr->zstream.msg);
+
+   png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
+
+   png_write_chunk_data(png_ptr, new_name, name_len);
+
+   png_write_compressed_data_out(png_ptr, &comp);
+
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sPLT_SUPPORTED
+/* Write a sPLT chunk */
+void /* PRIVATE */
+png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
+{
+   png_uint_32 name_len;
+   png_byte new_name[80];
+   png_byte entrybuf[10];
+   png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
+   png_size_t palette_size = entry_size * (png_size_t)spalette->nentries;
+   png_sPLT_entryp ep;
+#ifndef PNG_POINTER_INDEXING_SUPPORTED
+   int i;
+#endif
+
+   png_debug(1, "in png_write_sPLT");
+
+   name_len = png_check_keyword(png_ptr, spalette->name, new_name);
+
+   if (name_len == 0)
+      png_error(png_ptr, "sPLT: invalid keyword");
+
+   /* Make sure we include the NULL after the name */
+   png_write_chunk_header(png_ptr, png_sPLT,
+       (png_uint_32)(name_len + 2 + palette_size));
+
+   png_write_chunk_data(png_ptr, (png_bytep)new_name,
+       (png_size_t)(name_len + 1));
+
+   png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
+
+   /* Loop through each palette entry, writing appropriately */
+#ifdef PNG_POINTER_INDEXING_SUPPORTED
+   for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
+   {
+      if (spalette->depth == 8)
+      {
+         entrybuf[0] = (png_byte)ep->red;
+         entrybuf[1] = (png_byte)ep->green;
+         entrybuf[2] = (png_byte)ep->blue;
+         entrybuf[3] = (png_byte)ep->alpha;
+         png_save_uint_16(entrybuf + 4, ep->frequency);
+      }
+
+      else
+      {
+         png_save_uint_16(entrybuf + 0, ep->red);
+         png_save_uint_16(entrybuf + 2, ep->green);
+         png_save_uint_16(entrybuf + 4, ep->blue);
+         png_save_uint_16(entrybuf + 6, ep->alpha);
+         png_save_uint_16(entrybuf + 8, ep->frequency);
+      }
+
+      png_write_chunk_data(png_ptr, entrybuf, entry_size);
+   }
+#else
+   ep=spalette->entries;
+   for (i = 0; i>spalette->nentries; i++)
+   {
+      if (spalette->depth == 8)
+      {
+         entrybuf[0] = (png_byte)ep[i].red;
+         entrybuf[1] = (png_byte)ep[i].green;
+         entrybuf[2] = (png_byte)ep[i].blue;
+         entrybuf[3] = (png_byte)ep[i].alpha;
+         png_save_uint_16(entrybuf + 4, ep[i].frequency);
+      }
+
+      else
+      {
+         png_save_uint_16(entrybuf + 0, ep[i].red);
+         png_save_uint_16(entrybuf + 2, ep[i].green);
+         png_save_uint_16(entrybuf + 4, ep[i].blue);
+         png_save_uint_16(entrybuf + 6, ep[i].alpha);
+         png_save_uint_16(entrybuf + 8, ep[i].frequency);
+      }
+
+      png_write_chunk_data(png_ptr, entrybuf, entry_size);
+   }
+#endif
+
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sBIT_SUPPORTED
+/* Write the sBIT chunk */
+void /* PRIVATE */
+png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
+{
+   png_byte buf[4];
+   png_size_t size;
+
+   png_debug(1, "in png_write_sBIT");
+
+   /* Make sure we don't depend upon the order of PNG_COLOR_8 */
+   if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      png_byte maxbits;
+
+      maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
+          png_ptr->usr_bit_depth);
+
+      if (sbit->red == 0 || sbit->red > maxbits ||
+          sbit->green == 0 || sbit->green > maxbits ||
+          sbit->blue == 0 || sbit->blue > maxbits)
+      {
+         png_warning(png_ptr, "Invalid sBIT depth specified");
+         return;
+      }
+
+      buf[0] = sbit->red;
+      buf[1] = sbit->green;
+      buf[2] = sbit->blue;
+      size = 3;
+   }
+
+   else
+   {
+      if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
+      {
+         png_warning(png_ptr, "Invalid sBIT depth specified");
+         return;
+      }
+
+      buf[0] = sbit->gray;
+      size = 1;
+   }
+
+   if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
+   {
+      if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
+      {
+         png_warning(png_ptr, "Invalid sBIT depth specified");
+         return;
+      }
+
+      buf[size++] = sbit->alpha;
+   }
+
+   png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
+}
+#endif
+
+#ifdef PNG_WRITE_cHRM_SUPPORTED
+/* Write the cHRM chunk */
+void /* PRIVATE */
+png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
+{
+   png_byte buf[32];
+
+   png_debug(1, "in png_write_cHRM");
+
+   /* Each value is saved in 1/100,000ths */
+   png_save_int_32(buf,      xy->whitex);
+   png_save_int_32(buf +  4, xy->whitey);
+
+   png_save_int_32(buf +  8, xy->redx);
+   png_save_int_32(buf + 12, xy->redy);
+
+   png_save_int_32(buf + 16, xy->greenx);
+   png_save_int_32(buf + 20, xy->greeny);
+
+   png_save_int_32(buf + 24, xy->bluex);
+   png_save_int_32(buf + 28, xy->bluey);
+
+   png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
+}
+#endif
+
+#ifdef PNG_WRITE_tRNS_SUPPORTED
+/* Write the tRNS chunk */
+void /* PRIVATE */
+png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
+    png_const_color_16p tran, int num_trans, int color_type)
+{
+   png_byte buf[6];
+
+   png_debug(1, "in png_write_tRNS");
+
+   if (color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
+      {
+         png_app_warning(png_ptr,
+             "Invalid number of transparent colors specified");
+         return;
+      }
+
+      /* Write the chunk out as it is */
+      png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
+          (png_size_t)num_trans);
+   }
+
+   else if (color_type == PNG_COLOR_TYPE_GRAY)
+   {
+      /* One 16-bit value */
+      if (tran->gray >= (1 << png_ptr->bit_depth))
+      {
+         png_app_warning(png_ptr,
+             "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+
+         return;
+      }
+
+      png_save_uint_16(buf, tran->gray);
+      png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
+   }
+
+   else if (color_type == PNG_COLOR_TYPE_RGB)
+   {
+      /* Three 16-bit values */
+      png_save_uint_16(buf, tran->red);
+      png_save_uint_16(buf + 2, tran->green);
+      png_save_uint_16(buf + 4, tran->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+      if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
+      {
+         png_app_warning(png_ptr,
+             "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+         return;
+      }
+
+      png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
+   }
+
+   else
+   {
+      png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_bKGD_SUPPORTED
+/* Write the background chunk */
+void /* PRIVATE */
+png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
+{
+   png_byte buf[6];
+
+   png_debug(1, "in png_write_bKGD");
+
+   if (color_type == PNG_COLOR_TYPE_PALETTE)
+   {
+      if (
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+          (png_ptr->num_palette != 0 ||
+          (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) &&
+#endif
+         back->index >= png_ptr->num_palette)
+      {
+         png_warning(png_ptr, "Invalid background palette index");
+         return;
+      }
+
+      buf[0] = back->index;
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
+   }
+
+   else if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
+   {
+      png_save_uint_16(buf, back->red);
+      png_save_uint_16(buf + 2, back->green);
+      png_save_uint_16(buf + 4, back->blue);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
+#else
+      if ((buf[0] | buf[2] | buf[4]) != 0)
+#endif
+      {
+         png_warning(png_ptr,
+             "Ignoring attempt to write 16-bit bKGD chunk "
+             "when bit_depth is 8");
+
+         return;
+      }
+
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
+   }
+
+   else
+   {
+      if (back->gray >= (1 << png_ptr->bit_depth))
+      {
+         png_warning(png_ptr,
+             "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+
+         return;
+      }
+
+      png_save_uint_16(buf, back->gray);
+      png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
+   }
+}
+#endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+/* Write the Exif data */
+void /* PRIVATE */
+png_write_eXIf(png_structrp png_ptr, png_bytep exif, int num_exif)
+{
+   int i;
+   png_byte buf[1];
+
+   png_debug(1, "in png_write_eXIf");
+
+   png_write_chunk_header(png_ptr, png_eXIf, (png_uint_32)(num_exif));
+
+   for (i = 0; i < num_exif; i++)
+   {
+      buf[0] = exif[i];
+      png_write_chunk_data(png_ptr, buf, (png_size_t)1);
+   }
+
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_hIST_SUPPORTED
+/* Write the histogram */
+void /* PRIVATE */
+png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
+{
+   int i;
+   png_byte buf[3];
+
+   png_debug(1, "in png_write_hIST");
+
+   if (num_hist > (int)png_ptr->num_palette)
+   {
+      png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
+          png_ptr->num_palette);
+
+      png_warning(png_ptr, "Invalid number of histogram entries specified");
+      return;
+   }
+
+   png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
+
+   for (i = 0; i < num_hist; i++)
+   {
+      png_save_uint_16(buf, hist[i]);
+      png_write_chunk_data(png_ptr, buf, (png_size_t)2);
+   }
+
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_tEXt_SUPPORTED
+/* Write a tEXt chunk */
+void /* PRIVATE */
+png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+    png_size_t text_len)
+{
+   png_uint_32 key_len;
+   png_byte new_key[80];
+
+   png_debug(1, "in png_write_tEXt");
+
+   key_len = png_check_keyword(png_ptr, key, new_key);
+
+   if (key_len == 0)
+      png_error(png_ptr, "tEXt: invalid keyword");
+
+   if (text == NULL || *text == '\0')
+      text_len = 0;
+
+   else
+      text_len = strlen(text);
+
+   if (text_len > PNG_UINT_31_MAX - (key_len+1))
+      png_error(png_ptr, "tEXt: text too long");
+
+   /* Make sure we include the 0 after the key */
+   png_write_chunk_header(png_ptr, png_tEXt,
+       (png_uint_32)/*checked above*/(key_len + text_len + 1));
+   /*
+    * We leave it to the application to meet PNG-1.0 requirements on the
+    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
+    * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
+    * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+    */
+   png_write_chunk_data(png_ptr, new_key, key_len + 1);
+
+   if (text_len != 0)
+      png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
+
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_zTXt_SUPPORTED
+/* Write a compressed text chunk */
+void /* PRIVATE */
+png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
+    int compression)
+{
+   png_uint_32 key_len;
+   png_byte new_key[81];
+   compression_state comp;
+
+   png_debug(1, "in png_write_zTXt");
+
+   if (compression == PNG_TEXT_COMPRESSION_NONE)
+   {
+      png_write_tEXt(png_ptr, key, text, 0);
+      return;
+   }
+
+   if (compression != PNG_TEXT_COMPRESSION_zTXt)
+      png_error(png_ptr, "zTXt: invalid compression type");
+
+   key_len = png_check_keyword(png_ptr, key, new_key);
+
+   if (key_len == 0)
+      png_error(png_ptr, "zTXt: invalid keyword");
+
+   /* Add the compression method and 1 for the keyword separator. */
+   new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+   ++key_len;
+
+   /* Compute the compressed data; do it now for the length */
+   png_text_compress_init(&comp, (png_const_bytep)text,
+       text == NULL ? 0 : strlen(text));
+
+   if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
+      png_error(png_ptr, png_ptr->zstream.msg);
+
+   /* Write start of chunk */
+   png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
+
+   /* Write key */
+   png_write_chunk_data(png_ptr, new_key, key_len);
+
+   /* Write the compressed data */
+   png_write_compressed_data_out(png_ptr, &comp);
+
+   /* Close the chunk */
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+/* Write an iTXt chunk */
+void /* PRIVATE */
+png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
+    png_const_charp lang, png_const_charp lang_key, png_const_charp text)
+{
+   png_uint_32 key_len, prefix_len;
+   png_size_t lang_len, lang_key_len;
+   png_byte new_key[82];
+   compression_state comp;
+
+   png_debug(1, "in png_write_iTXt");
+
+   key_len = png_check_keyword(png_ptr, key, new_key);
+
+   if (key_len == 0)
+      png_error(png_ptr, "iTXt: invalid keyword");
+
+   /* Set the compression flag */
+   switch (compression)
+   {
+      case PNG_ITXT_COMPRESSION_NONE:
+      case PNG_TEXT_COMPRESSION_NONE:
+         compression = new_key[++key_len] = 0; /* no compression */
+         break;
+
+      case PNG_TEXT_COMPRESSION_zTXt:
+      case PNG_ITXT_COMPRESSION_zTXt:
+         compression = new_key[++key_len] = 1; /* compressed */
+         break;
+
+      default:
+         png_error(png_ptr, "iTXt: invalid compression");
+   }
+
+   new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
+   ++key_len; /* for the keywod separator */
+
+   /* We leave it to the application to meet PNG-1.0 requirements on the
+    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
+    * any non-Latin-1 characters except for NEWLINE.  ISO PNG, however,
+    * specifies that the text is UTF-8 and this really doesn't require any
+    * checking.
+    *
+    * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
+    *
+    * TODO: validate the language tag correctly (see the spec.)
+    */
+   if (lang == NULL) lang = ""; /* empty language is valid */
+   lang_len = strlen(lang)+1;
+   if (lang_key == NULL) lang_key = ""; /* may be empty */
+   lang_key_len = strlen(lang_key)+1;
+   if (text == NULL) text = ""; /* may be empty */
+
+   prefix_len = key_len;
+   if (lang_len > PNG_UINT_31_MAX-prefix_len)
+      prefix_len = PNG_UINT_31_MAX;
+   else
+      prefix_len = (png_uint_32)(prefix_len + lang_len);
+
+   if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
+      prefix_len = PNG_UINT_31_MAX;
+   else
+      prefix_len = (png_uint_32)(prefix_len + lang_key_len);
+
+   png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
+
+   if (compression != 0)
+   {
+      if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
+         png_error(png_ptr, png_ptr->zstream.msg);
+   }
+
+   else
+   {
+      if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
+         png_error(png_ptr, "iTXt: uncompressed text too long");
+
+      /* So the string will fit in a chunk: */
+      comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
+   }
+
+   png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
+
+   png_write_chunk_data(png_ptr, new_key, key_len);
+
+   png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
+
+   png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
+
+   if (compression != 0)
+      png_write_compressed_data_out(png_ptr, &comp);
+
+   else
+      png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len);
+
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_oFFs_SUPPORTED
+/* Write the oFFs chunk */
+void /* PRIVATE */
+png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
+    int unit_type)
+{
+   png_byte buf[9];
+
+   png_debug(1, "in png_write_oFFs");
+
+   if (unit_type >= PNG_OFFSET_LAST)
+      png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
+
+   png_save_int_32(buf, x_offset);
+   png_save_int_32(buf + 4, y_offset);
+   buf[8] = (png_byte)unit_type;
+
+   png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
+}
+#endif
+#ifdef PNG_WRITE_pCAL_SUPPORTED
+/* Write the pCAL chunk (described in the PNG extensions document) */
+void /* PRIVATE */
+png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
+    png_int_32 X1, int type, int nparams, png_const_charp units,
+    png_charpp params)
+{
+   png_uint_32 purpose_len;
+   png_size_t units_len, total_len;
+   png_size_tp params_len;
+   png_byte buf[10];
+   png_byte new_purpose[80];
+   int i;
+
+   png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
+
+   if (type >= PNG_EQUATION_LAST)
+      png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
+
+   purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
+
+   if (purpose_len == 0)
+      png_error(png_ptr, "pCAL: invalid keyword");
+
+   ++purpose_len; /* terminator */
+
+   png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
+   units_len = strlen(units) + (nparams == 0 ? 0 : 1);
+   png_debug1(3, "pCAL units length = %d", (int)units_len);
+   total_len = purpose_len + units_len + 10;
+
+   params_len = (png_size_tp)png_malloc(png_ptr,
+       (png_alloc_size_t)((png_alloc_size_t)nparams * (sizeof (png_size_t))));
+
+   /* Find the length of each parameter, making sure we don't count the
+    * null terminator for the last parameter.
+    */
+   for (i = 0; i < nparams; i++)
+   {
+      params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
+      png_debug2(3, "pCAL parameter %d length = %lu", i,
+          (unsigned long)params_len[i]);
+      total_len += params_len[i];
+   }
+
+   png_debug1(3, "pCAL total length = %d", (int)total_len);
+   png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
+   png_write_chunk_data(png_ptr, new_purpose, purpose_len);
+   png_save_int_32(buf, X0);
+   png_save_int_32(buf + 4, X1);
+   buf[8] = (png_byte)type;
+   buf[9] = (png_byte)nparams;
+   png_write_chunk_data(png_ptr, buf, (png_size_t)10);
+   png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
+
+   for (i = 0; i < nparams; i++)
+   {
+      png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
+   }
+
+   png_free(png_ptr, params_len);
+   png_write_chunk_end(png_ptr);
+}
+#endif
+
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+/* Write the sCAL chunk */
+void /* PRIVATE */
+png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
+    png_const_charp height)
+{
+   png_byte buf[64];
+   png_size_t wlen, hlen, total_len;
+
+   png_debug(1, "in png_write_sCAL_s");
+
+   wlen = strlen(width);
+   hlen = strlen(height);
+   total_len = wlen + hlen + 2;
+
+   if (total_len > 64)
+   {
+      png_warning(png_ptr, "Can't write sCAL (buffer too small)");
+      return;
+   }
+
+   buf[0] = (png_byte)unit;
+   memcpy(buf + 1, width, wlen + 1);      /* Append the '\0' here */
+   memcpy(buf + wlen + 2, height, hlen);  /* Do NOT append the '\0' here */
+
+   png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
+   png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
+}
+#endif
+
+#ifdef PNG_WRITE_pHYs_SUPPORTED
+/* Write the pHYs chunk */
+void /* PRIVATE */
+png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
+    png_uint_32 y_pixels_per_unit,
+    int unit_type)
+{
+   png_byte buf[9];
+
+   png_debug(1, "in png_write_pHYs");
+
+   if (unit_type >= PNG_RESOLUTION_LAST)
+      png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
+
+   png_save_uint_32(buf, x_pixels_per_unit);
+   png_save_uint_32(buf + 4, y_pixels_per_unit);
+   buf[8] = (png_byte)unit_type;
+
+   png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
+}
+#endif
+
+#ifdef PNG_WRITE_tIME_SUPPORTED
+/* Write the tIME chunk.  Use either png_convert_from_struct_tm()
+ * or png_convert_from_time_t(), or fill in the structure yourself.
+ */
+void /* PRIVATE */
+png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
+{
+   png_byte buf[7];
+
+   png_debug(1, "in png_write_tIME");
+
+   if (mod_time->month  > 12 || mod_time->month  < 1 ||
+       mod_time->day    > 31 || mod_time->day    < 1 ||
+       mod_time->hour   > 23 || mod_time->second > 60)
+   {
+      png_warning(png_ptr, "Invalid time specified for tIME chunk");
+      return;
+   }
+
+   png_save_uint_16(buf, mod_time->year);
+   buf[2] = mod_time->month;
+   buf[3] = mod_time->day;
+   buf[4] = mod_time->hour;
+   buf[5] = mod_time->minute;
+   buf[6] = mod_time->second;
+
+   png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
+}
+#endif
+
+/* Initializes the row writing capability of libpng */
+void /* PRIVATE */
+png_write_start_row(png_structrp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+   png_alloc_size_t buf_size;
+   int usr_pixel_depth;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_byte filters;
+#endif
+
+   png_debug(1, "in png_write_start_row");
+
+   usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
+   buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
+
+   /* 1.5.6: added to allow checking in the row write code. */
+   png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
+   png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
+
+   /* Set up row buffer */
+   png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
+   png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   filters = png_ptr->do_filter;
+
+   if (png_ptr->height == 1)
+      filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+   if (png_ptr->width == 1)
+      filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+   if (filters == 0)
+      filters = PNG_FILTER_NONE;
+
+   png_ptr->do_filter = filters;
+
+   if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG |
+       PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL)
+   {
+      int num_filters = 0;
+
+      png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
+
+      if (filters & PNG_FILTER_SUB)
+         num_filters++;
+
+      if (filters & PNG_FILTER_UP)
+         num_filters++;
+
+      if (filters & PNG_FILTER_AVG)
+         num_filters++;
+
+      if (filters & PNG_FILTER_PAETH)
+         num_filters++;
+
+      if (num_filters > 1)
+         png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr,
+             buf_size));
+   }
+
+   /* We only need to keep the previous row if we are using one of the following
+    * filters.
+    */
+   if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0)
+      png_ptr->prev_row = png_voidcast(png_bytep,
+          png_calloc(png_ptr, buf_size));
+#endif /* WRITE_FILTER */
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* If interlaced, we need to set up width and height of pass */
+   if (png_ptr->interlaced != 0)
+   {
+      if ((png_ptr->transformations & PNG_INTERLACE) == 0)
+      {
+         png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
+             png_pass_ystart[0]) / png_pass_yinc[0];
+
+         png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
+             png_pass_start[0]) / png_pass_inc[0];
+      }
+
+      else
+      {
+         png_ptr->num_rows = png_ptr->height;
+         png_ptr->usr_width = png_ptr->width;
+      }
+   }
+
+   else
+#endif
+   {
+      png_ptr->num_rows = png_ptr->height;
+      png_ptr->usr_width = png_ptr->width;
+   }
+}
+
+/* Internal use only.  Called when finished processing a row of data. */
+void /* PRIVATE */
+png_write_finish_row(png_structrp png_ptr)
+{
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* Start of interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* Offset to next interlace block in the y direction */
+   static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif
+
+   png_debug(1, "in png_write_finish_row");
+
+   /* Next row */
+   png_ptr->row_number++;
+
+   /* See if we are done */
+   if (png_ptr->row_number < png_ptr->num_rows)
+      return;
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+   /* If interlaced, go to next pass */
+   if (png_ptr->interlaced != 0)
+   {
+      png_ptr->row_number = 0;
+      if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+      {
+         png_ptr->pass++;
+      }
+
+      else
+      {
+         /* Loop until we find a non-zero width or height pass */
+         do
+         {
+            png_ptr->pass++;
+
+            if (png_ptr->pass >= 7)
+               break;
+
+            png_ptr->usr_width = (png_ptr->width +
+                png_pass_inc[png_ptr->pass] - 1 -
+                png_pass_start[png_ptr->pass]) /
+                png_pass_inc[png_ptr->pass];
+
+            png_ptr->num_rows = (png_ptr->height +
+                png_pass_yinc[png_ptr->pass] - 1 -
+                png_pass_ystart[png_ptr->pass]) /
+                png_pass_yinc[png_ptr->pass];
+
+            if ((png_ptr->transformations & PNG_INTERLACE) != 0)
+               break;
+
+         } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
+
+      }
+
+      /* Reset the row above the image for the next pass */
+      if (png_ptr->pass < 7)
+      {
+         if (png_ptr->prev_row != NULL)
+            memset(png_ptr->prev_row, 0,
+                (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
+                png_ptr->usr_bit_depth, png_ptr->width)) + 1);
+
+         return;
+      }
+   }
+#endif
+
+   /* If we get here, we've just written the last row, so we need
+      to flush the compressor */
+   png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
+}
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
+/* Pick out the correct pixels for the interlace pass.
+ * The basic idea here is to go through the row with a source
+ * pointer and a destination pointer (sp and dp), and copy the
+ * correct pixels for the pass.  As the row gets compacted,
+ * sp will always be >= dp, so we should never overwrite anything.
+ * See the default: case for the easiest code to understand.
+ */
+void /* PRIVATE */
+png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* Start of interlace block */
+   static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* Offset to next interlace block */
+   static PNG_CONST png_byte  png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+
+   png_debug(1, "in png_do_write_interlace");
+
+   /* We don't have to do anything on the last pass (6) */
+   if (pass < 6)
+   {
+      /* Each pixel depth is handled separately */
+      switch (row_info->pixel_depth)
+      {
+         case 1:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            unsigned int shift;
+            int d;
+            int value;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            dp = row;
+            d = 0;
+            shift = 7;
+
+            for (i = png_pass_start[pass]; i < row_width;
+               i += png_pass_inc[pass])
+            {
+               sp = row + (png_size_t)(i >> 3);
+               value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
+               d |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 7;
+                  *dp++ = (png_byte)d;
+                  d = 0;
+               }
+
+               else
+                  shift--;
+
+            }
+            if (shift != 7)
+               *dp = (png_byte)d;
+
+            break;
+         }
+
+         case 2:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            unsigned int shift;
+            int d;
+            int value;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            dp = row;
+            shift = 6;
+            d = 0;
+
+            for (i = png_pass_start[pass]; i < row_width;
+               i += png_pass_inc[pass])
+            {
+               sp = row + (png_size_t)(i >> 2);
+               value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
+               d |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 6;
+                  *dp++ = (png_byte)d;
+                  d = 0;
+               }
+
+               else
+                  shift -= 2;
+            }
+            if (shift != 6)
+               *dp = (png_byte)d;
+
+            break;
+         }
+
+         case 4:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            unsigned int shift;
+            int d;
+            int value;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+
+            dp = row;
+            shift = 4;
+            d = 0;
+            for (i = png_pass_start[pass]; i < row_width;
+                i += png_pass_inc[pass])
+            {
+               sp = row + (png_size_t)(i >> 1);
+               value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
+               d |= (value << shift);
+
+               if (shift == 0)
+               {
+                  shift = 4;
+                  *dp++ = (png_byte)d;
+                  d = 0;
+               }
+
+               else
+                  shift -= 4;
+            }
+            if (shift != 4)
+               *dp = (png_byte)d;
+
+            break;
+         }
+
+         default:
+         {
+            png_bytep sp;
+            png_bytep dp;
+            png_uint_32 i;
+            png_uint_32 row_width = row_info->width;
+            png_size_t pixel_bytes;
+
+            /* Start at the beginning */
+            dp = row;
+
+            /* Find out how many bytes each pixel takes up */
+            pixel_bytes = (row_info->pixel_depth >> 3);
+
+            /* Loop through the row, only looking at the pixels that matter */
+            for (i = png_pass_start[pass]; i < row_width;
+               i += png_pass_inc[pass])
+            {
+               /* Find out where the original pixel is */
+               sp = row + (png_size_t)i * pixel_bytes;
+
+               /* Move the pixel */
+               if (dp != sp)
+                  memcpy(dp, sp, pixel_bytes);
+
+               /* Next pixel */
+               dp += pixel_bytes;
+            }
+            break;
+         }
+      }
+      /* Set new row width */
+      row_info->width = (row_info->width +
+          png_pass_inc[pass] - 1 -
+          png_pass_start[pass]) /
+          png_pass_inc[pass];
+
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+          row_info->width);
+   }
+}
+#endif
+
+
+/* This filters the row, chooses which filter to use, if it has not already
+ * been specified by the application, and then writes the row out with the
+ * chosen filter.
+ */
+static void /* PRIVATE */
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+    png_size_t row_bytes);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+static png_size_t /* PRIVATE */
+png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes, const png_size_t lmins)
+{
+   png_bytep rp, dp, lp;
+   png_size_t i;
+   png_size_t sum = 0;
+   unsigned int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+        i++, rp++, dp++)
+   {
+      v = *dp = *rp;
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+   }
+
+   for (lp = png_ptr->row_buf + 1; i < row_bytes;
+      i++, rp++, lp++, dp++)
+   {
+      v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+
+static void /* PRIVATE */
+png_setup_sub_row_only(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes)
+{
+   png_bytep rp, dp, lp;
+   png_size_t i;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
+        i++, rp++, dp++)
+   {
+      *dp = *rp;
+   }
+
+   for (lp = png_ptr->row_buf + 1; i < row_bytes;
+      i++, rp++, lp++, dp++)
+   {
+      *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
+   }
+}
+
+static png_size_t /* PRIVATE */
+png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
+    const png_size_t lmins)
+{
+   png_bytep rp, dp, pp;
+   png_size_t i;
+   png_size_t sum = 0;
+   unsigned int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < row_bytes;
+       i++, rp++, pp++, dp++)
+   {
+      v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+static void /* PRIVATE */
+png_setup_up_row_only(png_structrp png_ptr, const png_size_t row_bytes)
+{
+   png_bytep rp, dp, pp;
+   png_size_t i;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < row_bytes;
+       i++, rp++, pp++, dp++)
+   {
+      *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
+   }
+}
+
+static png_size_t /* PRIVATE */
+png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes, const png_size_t lmins)
+{
+   png_bytep rp, dp, pp, lp;
+   png_uint_32 i;
+   png_size_t sum = 0;
+   unsigned int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < bpp; i++)
+   {
+      v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+   }
+
+   for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+   {
+      v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+          & 0xff);
+
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+static void /* PRIVATE */
+png_setup_avg_row_only(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes)
+{
+   png_bytep rp, dp, pp, lp;
+   png_uint_32 i;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < bpp; i++)
+   {
+      *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
+   }
+
+   for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
+   {
+      *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
+          & 0xff);
+   }
+}
+
+static png_size_t /* PRIVATE */
+png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes, const png_size_t lmins)
+{
+   png_bytep rp, dp, pp, cp, lp;
+   png_size_t i;
+   png_size_t sum = 0;
+   unsigned int v;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < bpp; i++)
+   {
+      v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+   }
+
+   for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+        i++)
+   {
+      int a, b, c, pa, pb, pc, p;
+
+      b = *pp++;
+      c = *cp++;
+      a = *lp++;
+
+      p = b - c;
+      pc = a - c;
+
+#ifdef PNG_USE_ABS
+      pa = abs(p);
+      pb = abs(pc);
+      pc = abs(p + pc);
+#else
+      pa = p < 0 ? -p : p;
+      pb = pc < 0 ? -pc : pc;
+      pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+      p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+      v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+
+#ifdef PNG_USE_ABS
+      sum += 128 - abs((int)v - 128);
+#else
+      sum += (v < 128) ? v : 256 - v;
+#endif
+
+      if (sum > lmins)  /* We are already worse, don't continue. */
+        break;
+   }
+
+   return (sum);
+}
+static void /* PRIVATE */
+png_setup_paeth_row_only(png_structrp png_ptr, const png_uint_32 bpp,
+    const png_size_t row_bytes)
+{
+   png_bytep rp, dp, pp, cp, lp;
+   png_size_t i;
+
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
+   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
+       pp = png_ptr->prev_row + 1; i < bpp; i++)
+   {
+      *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
+   }
+
+   for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
+        i++)
+   {
+      int a, b, c, pa, pb, pc, p;
+
+      b = *pp++;
+      c = *cp++;
+      a = *lp++;
+
+      p = b - c;
+      pc = a - c;
+
+#ifdef PNG_USE_ABS
+      pa = abs(p);
+      pb = abs(pc);
+      pc = abs(p + pc);
+#else
+      pa = p < 0 ? -p : p;
+      pb = pc < 0 ? -pc : pc;
+      pc = (p + pc) < 0 ? -(p + pc) : p + pc;
+#endif
+
+      p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+
+      *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
+   }
+}
+#endif /* WRITE_FILTER */
+
+void /* PRIVATE */
+png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
+{
+#ifndef PNG_WRITE_FILTER_SUPPORTED
+   png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1);
+#else
+   unsigned int filter_to_do = png_ptr->do_filter;
+   png_bytep row_buf;
+   png_bytep best_row;
+   png_uint_32 bpp;
+   png_size_t mins;
+   png_size_t row_bytes = row_info->rowbytes;
+
+   png_debug(1, "in png_write_find_filter");
+
+   /* Find out how many bytes offset each pixel is */
+   bpp = (row_info->pixel_depth + 7) >> 3;
+
+   row_buf = png_ptr->row_buf;
+   mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the
+                               running sum */;
+
+   /* The prediction method we use is to find which method provides the
+    * smallest value when summing the absolute values of the distances
+    * from zero, using anything >= 128 as negative numbers.  This is known
+    * as the "minimum sum of absolute differences" heuristic.  Other
+    * heuristics are the "weighted minimum sum of absolute differences"
+    * (experimental and can in theory improve compression), and the "zlib
+    * predictive" method (not implemented yet), which does test compressions
+    * of lines using different filter methods, and then chooses the
+    * (series of) filter(s) that give minimum compressed data size (VERY
+    * computationally expensive).
+    *
+    * GRR 980525:  consider also
+    *
+    *   (1) minimum sum of absolute differences from running average (i.e.,
+    *       keep running sum of non-absolute differences & count of bytes)
+    *       [track dispersion, too?  restart average if dispersion too large?]
+    *
+    *  (1b) minimum sum of absolute differences from sliding average, probably
+    *       with window size <= deflate window (usually 32K)
+    *
+    *   (2) minimum sum of squared differences from zero or running average
+    *       (i.e., ~ root-mean-square approach)
+    */
+
+
+   /* We don't need to test the 'no filter' case if this is the only filter
+    * that has been chosen, as it doesn't actually do anything to the data.
+    */
+   best_row = png_ptr->row_buf;
+
+   if (PNG_SIZE_MAX/128 <= row_bytes)
+   {
+      /* Overflow can occur in the calculation, just select the lowest set
+       * filter.
+       */
+      filter_to_do &= 0U-filter_to_do;
+   }
+   else if ((filter_to_do & PNG_FILTER_NONE) != 0 &&
+         filter_to_do != PNG_FILTER_NONE)
+   {
+      /* Overflow not possible and multiple filters in the list, including the
+       * 'none' filter.
+       */
+      png_bytep rp;
+      png_size_t sum = 0;
+      png_size_t i;
+      unsigned int v;
+
+      {
+         for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
+         {
+            v = *rp;
+#ifdef PNG_USE_ABS
+            sum += 128 - abs((int)v - 128);
+#else
+            sum += (v < 128) ? v : 256 - v;
+#endif
+         }
+      }
+
+      mins = sum;
+   }
+
+   /* Sub filter */
+   if (filter_to_do == PNG_FILTER_SUB)
+   /* It's the only filter so no testing is needed */
+   {
+      png_setup_sub_row_only(png_ptr, bpp, row_bytes);
+      best_row = png_ptr->try_row;
+   }
+
+   else if ((filter_to_do & PNG_FILTER_SUB) != 0)
+   {
+      png_size_t sum;
+      png_size_t lmins = mins;
+
+      sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins);
+
+      if (sum < mins)
+      {
+         mins = sum;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
+      }
+   }
+
+   /* Up filter */
+   if (filter_to_do == PNG_FILTER_UP)
+   {
+      png_setup_up_row_only(png_ptr, row_bytes);
+      best_row = png_ptr->try_row;
+   }
+
+   else if ((filter_to_do & PNG_FILTER_UP) != 0)
+   {
+      png_size_t sum;
+      png_size_t lmins = mins;
+
+      sum = png_setup_up_row(png_ptr, row_bytes, lmins);
+
+      if (sum < mins)
+      {
+         mins = sum;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
+      }
+   }
+
+   /* Avg filter */
+   if (filter_to_do == PNG_FILTER_AVG)
+   {
+      png_setup_avg_row_only(png_ptr, bpp, row_bytes);
+      best_row = png_ptr->try_row;
+   }
+
+   else if ((filter_to_do & PNG_FILTER_AVG) != 0)
+   {
+      png_size_t sum;
+      png_size_t lmins = mins;
+
+      sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins);
+
+      if (sum < mins)
+      {
+         mins = sum;
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
+      }
+   }
+
+   /* Paeth filter */
+   if (filter_to_do == PNG_FILTER_PAETH)
+   {
+      png_setup_paeth_row_only(png_ptr, bpp, row_bytes);
+      best_row = png_ptr->try_row;
+   }
+
+   else if ((filter_to_do & PNG_FILTER_PAETH) != 0)
+   {
+      png_size_t sum;
+      png_size_t lmins = mins;
+
+      sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins);
+
+      if (sum < mins)
+      {
+         best_row = png_ptr->try_row;
+         if (png_ptr->tst_row != NULL)
+         {
+            png_ptr->try_row = png_ptr->tst_row;
+            png_ptr->tst_row = best_row;
+         }
+      }
+   }
+
+   /* Do the actual writing of the filtered row data from the chosen filter. */
+   png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
+
+#endif /* WRITE_FILTER */
+}
+
+
+/* Do the actual writing of a previously filtered row. */
+static void
+png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
+    png_size_t full_row_length/*includes filter byte*/)
+{
+   png_debug(1, "in png_write_filtered_row");
+
+   png_debug1(2, "filter = %d", filtered_row[0]);
+
+   png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
+
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   /* Swap the current and previous rows */
+   if (png_ptr->prev_row != NULL)
+   {
+      png_bytep tptr;
+
+      tptr = png_ptr->prev_row;
+      png_ptr->prev_row = png_ptr->row_buf;
+      png_ptr->row_buf = tptr;
+   }
+#endif /* WRITE_FILTER */
+
+   /* Finish row - updates counters and flushes zlib if last row */
+   png_write_finish_row(png_ptr);
+
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+   png_ptr->flush_rows++;
+
+   if (png_ptr->flush_dist > 0 &&
+       png_ptr->flush_rows >= png_ptr->flush_dist)
+   {
+      png_write_flush(png_ptr);
+   }
+#endif /* WRITE_FLUSH */
+}
+#endif /* WRITE */
diff --git a/xs/src/png/libpng/scripts/genchk.cmake.in b/xs/src/png/libpng/scripts/genchk.cmake.in
new file mode 100644
index 000000000..ab3b9d746
--- /dev/null
+++ b/xs/src/png/libpng/scripts/genchk.cmake.in
@@ -0,0 +1,37 @@
+# genchk.cmake.in
+# Generate .chk from .out with awk (generic), based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+
+set(AWK "@AWK@")
+
+get_filename_component(INPUTEXT "${INPUT}" EXT)
+get_filename_component(OUTPUTEXT "${OUTPUT}" EXT)
+get_filename_component(INPUTBASE "${INPUT}" NAME_WE)
+get_filename_component(OUTPUTBASE "${OUTPUT}" NAME_WE)
+get_filename_component(INPUTDIR "${INPUT}" PATH)
+get_filename_component(OUTPUTDIR "${OUTPUT}" PATH)
+
+if("${INPUTEXT}" STREQUAL ".out" AND "${OUTPUTEXT}" STREQUAL ".chk")
+  # Generate .chk from .out with awk (generic)
+  file(REMOVE "${OUTPUT}" "${OUTPUTDIR}/${OUTPUTBASE}.new")
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/checksym.awk"
+                          "${SRCDIR}/scripts/${INPUTBASE}.def"
+                          "of=${OUTPUTDIR}/${OUTPUTBASE}.new"
+                          "${INPUT}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUTDIR}/${OUTPUTBASE}.new")
+  endif()
+  file(RENAME "${OUTPUTDIR}/${OUTPUTBASE}.new" "${OUTPUT}")
+else()
+  message(FATAL_ERROR "Unsupported conversion: ${INPUTEXT} to ${OUTPUTEXT}")
+endif()
diff --git a/xs/src/png/libpng/scripts/genout.cmake.in b/xs/src/png/libpng/scripts/genout.cmake.in
new file mode 100644
index 000000000..01f12de2f
--- /dev/null
+++ b/xs/src/png/libpng/scripts/genout.cmake.in
@@ -0,0 +1,93 @@
+# genout.cmake.in
+# Generate .out from .c with awk (generic), based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+set(BINDIR "@CMAKE_CURRENT_BINARY_DIR@")
+
+set(AWK "@AWK@")
+set(CMAKE_C_COMPILER "@CMAKE_C_COMPILER@")
+set(CMAKE_C_FLAGS @CMAKE_C_FLAGS@)
+set(INCDIR "@CMAKE_CURRENT_BINARY_DIR@")
+set(PNG_PREFIX "@PNG_PREFIX@")
+set(PNGLIB_MAJOR "@PNGLIB_MAJOR@")
+set(PNGLIB_MINOR "@PNGLIB_MINOR@")
+set(PNGLIB_VERSION "@PNGLIB_VERSION@")
+set(ZLIBINCDIR "@ZLIB_INCLUDE_DIR@")
+
+set(PLATFORM_C_FLAGS)
+if(APPLE)
+  set(CMAKE_OSX_ARCHITECTURES "@CMAKE_OSX_ARCHITECTURES@")
+  set(CMAKE_OSX_SYSROOT "@CMAKE_OSX_SYSROOT@")
+  if(CMAKE_OSX_ARCHITECTURES)
+    set(PLATFORM_C_FLAGS ${PLATFORM_C_FLAGS} -arch ${CMAKE_OSX_ARCHITECTURES})
+  endif()
+  if(CMAKE_OSX_SYSROOT)
+    set(PLATFORM_C_FLAGS ${PLATFORM_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT})
+  endif()
+endif()
+
+get_filename_component(INPUTEXT "${INPUT}" EXT)
+get_filename_component(OUTPUTEXT "${OUTPUT}" EXT)
+get_filename_component(INPUTBASE "${INPUT}" NAME_WE)
+get_filename_component(OUTPUTBASE "${OUTPUT}" NAME_WE)
+get_filename_component(INPUTDIR "${INPUT}" PATH)
+get_filename_component(OUTPUTDIR "${OUTPUT}" PATH)
+
+if ("${INPUTEXT}" STREQUAL ".c" AND "${OUTPUTEXT}" STREQUAL ".out")
+  get_filename_component(GENDIR "${OUTPUT}" PATH)
+  file(MAKE_DIRECTORY "${GENDIR}")
+
+  file(REMOVE "${OUTPUT}.tf1" "${OUTPUT}.tf2")
+
+  set(INCLUDES "-I${INCDIR}")
+  if(ZLIBINCDIR)
+    foreach(dir ${ZLIBINCDIR})
+      list(APPEND INCLUDES "-I${dir}")
+    endforeach()
+  endif()
+
+  if(PNG_PREFIX)
+    set(PNG_PREFIX_DEF "-DPNG_PREFIX=${PNG_PREFIX}")
+  endif()
+
+  execute_process(COMMAND "${CMAKE_C_COMPILER}" "-E"
+                          ${CMAKE_C_FLAGS}
+                          ${PLATFORM_C_FLAGS}
+                          "-I${SRCDIR}"
+                          "-I${BINDIR}"
+                          ${INCLUDES}
+                          "-DPNGLIB_LIBNAME=PNG${PNGLIB_MAJOR}${PNGLIB_MINOR}_0"
+                          "-DPNGLIB_VERSION=${PNGLIB_VERSION}"
+                          "-DSYMBOL_PREFIX=${SYMBOL_PREFIX}"
+                          "-DPNG_NO_USE_READ_MACROS"
+                          "-DPNG_BUILDING_SYMBOL_TABLE"
+                          ${PNG_PREFIX_DEF}
+                          "${INPUT}"
+                  OUTPUT_FILE "${OUTPUT}.tf1"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE CPP_FAIL)
+  if(CPP_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUT}.tf1")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/dfn.awk"
+                          "out=${OUTPUT}.tf2" "${OUTPUT}.tf1"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUT}.tf2")
+  endif()
+
+  file(REMOVE "${OUTPUT}.tf1")
+  file(RENAME "${OUTPUT}.tf2" "${OUTPUT}")
+else()
+  message(FATAL_ERROR "Unsupported conversion: ${INPUTEXT} to ${OUTPUTEXT}")
+endif()
diff --git a/xs/src/png/libpng/scripts/gensrc.cmake.in b/xs/src/png/libpng/scripts/gensrc.cmake.in
new file mode 100644
index 000000000..f28a62266
--- /dev/null
+++ b/xs/src/png/libpng/scripts/gensrc.cmake.in
@@ -0,0 +1,138 @@
+# gensrc.cmake.in
+# Generate source files with awk, based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+set(BINDIR "@CMAKE_CURRENT_BINARY_DIR@")
+
+set(AWK "@AWK@")
+set(DFA_XTRA "@DFA_XTRA@")
+set(PNG_PREFIX "@PNG_PREFIX@")
+set(PNGLIB_VERSION "@PNGLIB_VERSION@")
+
+if("${OUTPUT}" STREQUAL "scripts/pnglibconf.c")
+  # Generate scripts/pnglibconf.c
+
+  file(REMOVE "${BINDIR}/pnglibconf.tf6" "${BINDIR}/pnglibconf.tf7")
+
+  execute_process(COMMAND "${CMAKE_COMMAND}" -E echo "com ${PNGLIB_VERSION} STANDARD API DEFINITION"
+                  COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                          "out=pnglibconf.tf6" "logunsupported=1" "version=search"
+                          "${SRCDIR}/pngconf.h" "-"
+                          "${SRCDIR}/scripts/pnglibconf.dfa"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf6")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                  "out=pnglibconf.tf7" "pnglibconf.tf6"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf7")
+  endif()
+
+  file(REMOVE "pnglibconf.tf6")
+  file(MAKE_DIRECTORY "${BINDIR}/scripts")
+  file(RENAME "pnglibconf.tf7" "${BINDIR}/scripts/pnglibconf.c")
+
+elseif ("${OUTPUT}" STREQUAL "pnglibconf.c")
+  # Generate pnglibconf.c
+
+  file(REMOVE "${BINDIR}/pnglibconf.tf4" "${BINDIR}/pnglibconf.tf5")
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                  out=pnglibconf.tf4 version=search
+                  ${SRCDIR}/pngconf.h ${SRCDIR}/scripts/pnglibconf.dfa
+                  ${SRCDIR}/pngusr.dfa ${DFA_XTRA}
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf4")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/options.awk"
+                  out=pnglibconf.tf5 pnglibconf.tf4
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate pnglibconf.tf5")
+  endif()
+
+  file(REMOVE "pnglibconf.tf4")
+  file(MAKE_DIRECTORY "${BINDIR}/scripts")
+  file(RENAME "pnglibconf.tf5" "${BINDIR}/pnglibconf.c")
+
+elseif ("${OUTPUT}" STREQUAL "pnglibconf.h")
+  # Generate pnglibconf.h
+
+  file(REMOVE "${BINDIR}/${OUTPUT}")
+  if(PNG_PREFIX)
+    file(REMOVE "pnglibconf.tf8")
+
+    execute_process(COMMAND "${AWK}" "s==0 && NR>1{print prev}
+                             s==0{prev=\$0}
+                             s==1{print \"#define\", \$1, \"${PNG_PREFIX}\" \$1}
+                             s==2{print \"#define ${PNG_PREFIX}png_\" \$1, \"PNG_\" \$1}
+                             END{print prev}" s=0 pnglibconf.out s=1 "${BINDIR}/scripts/prefix.out"
+                             s=2 "${SRCDIR}/scripts/macro.lst"
+                    OUTPUT_FILE pnglibconf.tf8
+                    RESULT_VARIABLE AWK_FAIL)
+    if(AWK_FAIL)
+      message(FATAL_ERROR "Failed to generate pnglibconf.tf8")
+    endif()
+
+    file(RENAME "pnglibconf.tf8" "${BINDIR}/${OUTPUT}")
+  else()
+    execute_process(COMMAND "${CMAKE_COMMAND}" -E copy "${BINDIR}/pnglibconf.out"
+                                                       "${BINDIR}/${OUTPUT}"
+                    RESULT_VARIABLE COPY_FAIL)
+    if(COPY_FAIL)
+      message(FATAL_ERROR "Failed to create pnglibconf.h")
+    endif()
+  endif()
+
+elseif ("${OUTPUT}" STREQUAL "pngprefix.h")
+  # Generate pngprefix.h
+
+  file(REMOVE "${BINDIR}/${OUTPUT}")
+
+  if(PNG_PREFIX)
+    file(REMOVE "pngprefix.tf1")
+
+    execute_process(COMMAND "${AWK}"
+                            "{print \"#define\", \$1, \"${PNG_PREFIX}\" \$1}"
+                            "${BINDIR}/scripts/intprefix.out"
+                    OUTPUT_FILE "pngprefix.tf1"
+                    RESULT_VARIABLE AWK_FAIL)
+    if(AWK_FAIL)
+      message(FATAL_ERROR "Failed to generate pngprefix.tf1")
+    endif()
+
+    file(RENAME "pngprefix.tf1" "${BINDIR}/${OUTPUT}")
+  else()
+    file(WRITE "${BINDIR}/${OUTPUT}" "/* No libpng symbol prefix configured. */")
+  endif()
+
+elseif("${OUTPUT}" STREQUAL "scripts/pnglibconf.h.prebuilt")
+  # Generate scripts/pnglibconf.h.prebuilt (fails build)
+
+  message(STATUS "Attempting to build scripts/pnglibconf.h.prebuilt")
+  message(STATUS "This is a machine generated file, but if you want to make")
+  message(STATUS "a new one simply build the 'genfiles' target, and copy")
+  message(STATUS "scripts/pnglibconf.out to scripts/pnglibconf.h.prebuilt")
+  message(STATUS "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)")
+  message(FATAL_ERROR "Stopping build")
+
+else()
+  message(FATAL_ERROR "Unsupported output: ${OUTPUT}")
+endif()
diff --git a/xs/src/png/libpng/scripts/libpng-config-body.in b/xs/src/png/libpng/scripts/libpng-config-body.in
new file mode 100644
index 000000000..b466432d5
--- /dev/null
+++ b/xs/src/png/libpng/scripts/libpng-config-body.in
@@ -0,0 +1,96 @@
+
+usage()
+{
+    cat <<EOF
+Usage: libpng-config [OPTION] ...
+
+Known values for OPTION are:
+
+  --prefix        print libpng prefix
+  --libdir        print path to directory containing library
+  --libs          print library linking information
+  --ccopts        print compiler options
+  --cppflags      print pre-processor flags
+  --cflags        print preprocessor flags, I_opts, and compiler options
+  --I_opts        print "-I" include options
+  --L_opts        print linker "-L" flags for dynamic linking
+  --R_opts        print dynamic linker "-R" or "-rpath" flags
+  --ldopts        print linker options
+  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)
+  --static        revise subsequent outputs for static linking
+  --help          print this help and exit
+  --version       print version information
+EOF
+
+    exit $1
+}
+
+if test $# -eq 0; then
+    usage 1
+fi
+
+while test $# -gt 0; do
+    case "$1" in
+
+    --prefix)
+        echo ${prefix}
+        ;;
+
+    --version)
+        echo ${version}
+        exit 0
+        ;;
+
+    --help)
+        usage 0
+        ;;
+
+    --ccopts)
+        echo ${ccopts}
+        ;;
+
+    --cppflags)
+        echo ${cppflags}
+        ;;
+
+    --cflags)
+        echo ${I_opts} ${cppflags} ${ccopts}
+        ;;
+
+    --libdir)
+        echo ${libdir}
+        ;;
+
+    --libs)
+        echo ${libs}
+        ;;
+
+    --I_opts)
+        echo ${I_opts}
+        ;;
+
+    --L_opts)
+        echo ${L_opts}
+        ;;
+
+    --R_opts)
+        echo ${R_opts}
+        ;;
+
+    --ldflags)
+        echo ${ldflags} ${L_opts} ${R_opts} ${libs}
+        ;;
+
+    --static)
+        R_opts=""
+        ;;
+
+    *)
+        usage
+        exit 1
+        ;;
+    esac
+    shift
+done
+
+exit 0
diff --git a/xs/src/png/libpng/scripts/libpng-config-head.in b/xs/src/png/libpng/scripts/libpng-config-head.in
new file mode 100644
index 000000000..64dd3987d
--- /dev/null
+++ b/xs/src/png/libpng/scripts/libpng-config-head.in
@@ -0,0 +1,24 @@
+#! /bin/sh
+
+# libpng-config
+# provides configuration info for libpng.
+
+# Copyright (C) 2002 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# Modeled after libxml-config.
+
+version=1.6.34
+prefix=""
+libdir=""
+libs=""
+I_opts=""
+L_opts=""
+R_opts=""
+cppflags=""
+ccopts=""
+ldopts=""
+
diff --git a/xs/src/png/libpng/scripts/libpng.pc.in b/xs/src/png/libpng/scripts/libpng.pc.in
new file mode 100644
index 000000000..33c65767b
--- /dev/null
+++ b/xs/src/png/libpng/scripts/libpng.pc.in
@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/libpng16
+
+Name: libpng
+Description: Loads and saves PNG files
+Version: 1.6.34
+Libs: -L${libdir} -lpng16
+Cflags: -I${includedir}
diff --git a/xs/src/png/libpng/scripts/pnglibconf.h.prebuilt b/xs/src/png/libpng/scripts/pnglibconf.h.prebuilt
new file mode 100644
index 000000000..53b5e442c
--- /dev/null
+++ b/xs/src/png/libpng/scripts/pnglibconf.h.prebuilt
@@ -0,0 +1,220 @@
+/* libpng 1.6.34 STANDARD API DEFINITION */
+
+/* pnglibconf.h - library build configuration */
+
+/* Libpng version 1.6.34 - September 29, 2017 */
+
+/* Copyright (c) 1998-2017 Glenn Randers-Pehrson */
+
+/* This code is released under the libpng license. */
+/* For conditions of distribution and use, see the disclaimer */
+/* and license in png.h */
+
+/* pnglibconf.h */
+/* Machine generated file: DO NOT EDIT */
+/* Derived from: scripts/pnglibconf.dfa */
+#ifndef PNGLCONF_H
+#define PNGLCONF_H
+/* options */
+#define PNG_16BIT_SUPPORTED
+#define PNG_ALIGNED_MEMORY_SUPPORTED
+/*#undef PNG_ARM_NEON_API_SUPPORTED*/
+/*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/
+/*#undef PNG_POWERPC_VSX_API_SUPPORTED*/
+/*#undef PNG_POWERPC_VSX_CHECK_SUPPORTED*/
+#define PNG_BENIGN_ERRORS_SUPPORTED
+#define PNG_BENIGN_READ_ERRORS_SUPPORTED
+/*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
+#define PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_COLORSPACE_SUPPORTED
+#define PNG_CONSOLE_IO_SUPPORTED
+#define PNG_CONVERT_tIME_SUPPORTED
+#define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
+#define PNG_ERROR_TEXT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#define PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#define PNG_FORMAT_AFIRST_SUPPORTED
+#define PNG_FORMAT_BGR_SUPPORTED
+#define PNG_GAMMA_SUPPORTED
+#define PNG_GET_PALETTE_MAX_SUPPORTED
+#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#define PNG_INCH_CONVERSIONS_SUPPORTED
+#define PNG_INFO_IMAGE_SUPPORTED
+#define PNG_IO_STATE_SUPPORTED
+#define PNG_MNG_FEATURES_SUPPORTED
+#define PNG_POINTER_INDEXING_SUPPORTED
+#define PNG_PROGRESSIVE_READ_SUPPORTED
+#define PNG_READ_16BIT_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
+#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_READ_BACKGROUND_SUPPORTED
+#define PNG_READ_BGR_SUPPORTED
+#define PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
+#define PNG_READ_EXPAND_16_SUPPORTED
+#define PNG_READ_EXPAND_SUPPORTED
+#define PNG_READ_FILLER_SUPPORTED
+#define PNG_READ_GAMMA_SUPPORTED
+#define PNG_READ_GET_PALETTE_MAX_SUPPORTED
+#define PNG_READ_GRAY_TO_RGB_SUPPORTED
+#define PNG_READ_INTERLACING_SUPPORTED
+#define PNG_READ_INT_FUNCTIONS_SUPPORTED
+#define PNG_READ_INVERT_ALPHA_SUPPORTED
+#define PNG_READ_INVERT_SUPPORTED
+#define PNG_READ_OPT_PLTE_SUPPORTED
+#define PNG_READ_PACKSWAP_SUPPORTED
+#define PNG_READ_PACK_SUPPORTED
+#define PNG_READ_QUANTIZE_SUPPORTED
+#define PNG_READ_RGB_TO_GRAY_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
+#define PNG_READ_SHIFT_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_STRIP_ALPHA_SUPPORTED
+#define PNG_READ_SUPPORTED
+#define PNG_READ_SWAP_ALPHA_SUPPORTED
+#define PNG_READ_SWAP_SUPPORTED
+#define PNG_READ_TEXT_SUPPORTED
+#define PNG_READ_TRANSFORMS_SUPPORTED
+#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_READ_USER_CHUNKS_SUPPORTED
+#define PNG_READ_USER_TRANSFORM_SUPPORTED
+#define PNG_READ_bKGD_SUPPORTED
+#define PNG_READ_cHRM_SUPPORTED
+#define PNG_READ_eXIf_SUPPORTED
+#define PNG_READ_gAMA_SUPPORTED
+#define PNG_READ_hIST_SUPPORTED
+#define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_iTXt_SUPPORTED
+#define PNG_READ_oFFs_SUPPORTED
+#define PNG_READ_pCAL_SUPPORTED
+#define PNG_READ_pHYs_SUPPORTED
+#define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_sCAL_SUPPORTED
+#define PNG_READ_sPLT_SUPPORTED
+#define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_tEXt_SUPPORTED
+#define PNG_READ_tIME_SUPPORTED
+#define PNG_READ_tRNS_SUPPORTED
+#define PNG_READ_zTXt_SUPPORTED
+#define PNG_SAVE_INT_32_SUPPORTED
+#define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SEQUENTIAL_READ_SUPPORTED
+#define PNG_SETJMP_SUPPORTED
+#define PNG_SET_OPTION_SUPPORTED
+#define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_SET_USER_LIMITS_SUPPORTED
+#define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_READ_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_READ_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
+#define PNG_SIMPLIFIED_WRITE_SUPPORTED
+#define PNG_STDIO_SUPPORTED
+#define PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_TEXT_SUPPORTED
+#define PNG_TIME_RFC1123_SUPPORTED
+#define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_USER_CHUNKS_SUPPORTED
+#define PNG_USER_LIMITS_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
+#define PNG_USER_TRANSFORM_INFO_SUPPORTED
+#define PNG_USER_TRANSFORM_PTR_SUPPORTED
+#define PNG_WARNINGS_SUPPORTED
+#define PNG_WRITE_16BIT_SUPPORTED
+#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#define PNG_WRITE_BGR_SUPPORTED
+#define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+#define PNG_WRITE_FILLER_SUPPORTED
+#define PNG_WRITE_FILTER_SUPPORTED
+#define PNG_WRITE_FLUSH_SUPPORTED
+#define PNG_WRITE_GET_PALETTE_MAX_SUPPORTED
+#define PNG_WRITE_INTERLACING_SUPPORTED
+#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED
+#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
+#define PNG_WRITE_INVERT_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+#define PNG_WRITE_PACKSWAP_SUPPORTED
+#define PNG_WRITE_PACK_SUPPORTED
+#define PNG_WRITE_SHIFT_SUPPORTED
+#define PNG_WRITE_SUPPORTED
+#define PNG_WRITE_SWAP_ALPHA_SUPPORTED
+#define PNG_WRITE_SWAP_SUPPORTED
+#define PNG_WRITE_TEXT_SUPPORTED
+#define PNG_WRITE_TRANSFORMS_SUPPORTED
+#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#define PNG_WRITE_USER_TRANSFORM_SUPPORTED
+#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
+#define PNG_WRITE_bKGD_SUPPORTED
+#define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_eXIf_SUPPORTED
+#define PNG_WRITE_gAMA_SUPPORTED
+#define PNG_WRITE_hIST_SUPPORTED
+#define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_iTXt_SUPPORTED
+#define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_pCAL_SUPPORTED
+#define PNG_WRITE_pHYs_SUPPORTED
+#define PNG_WRITE_sBIT_SUPPORTED
+#define PNG_WRITE_sCAL_SUPPORTED
+#define PNG_WRITE_sPLT_SUPPORTED
+#define PNG_WRITE_sRGB_SUPPORTED
+#define PNG_WRITE_tEXt_SUPPORTED
+#define PNG_WRITE_tIME_SUPPORTED
+#define PNG_WRITE_tRNS_SUPPORTED
+#define PNG_WRITE_zTXt_SUPPORTED
+#define PNG_bKGD_SUPPORTED
+#define PNG_cHRM_SUPPORTED
+#define PNG_eXIf_SUPPORTED
+#define PNG_gAMA_SUPPORTED
+#define PNG_hIST_SUPPORTED
+#define PNG_iCCP_SUPPORTED
+#define PNG_iTXt_SUPPORTED
+#define PNG_oFFs_SUPPORTED
+#define PNG_pCAL_SUPPORTED
+#define PNG_pHYs_SUPPORTED
+#define PNG_sBIT_SUPPORTED
+#define PNG_sCAL_SUPPORTED
+#define PNG_sPLT_SUPPORTED
+#define PNG_sRGB_SUPPORTED
+#define PNG_tEXt_SUPPORTED
+#define PNG_tIME_SUPPORTED
+#define PNG_tRNS_SUPPORTED
+#define PNG_zTXt_SUPPORTED
+/* end of options */
+/* settings */
+#define PNG_API_RULE 0
+#define PNG_DEFAULT_READ_MACROS 1
+#define PNG_GAMMA_THRESHOLD_FIXED 5000
+#define PNG_IDAT_READ_SIZE PNG_ZBUF_SIZE
+#define PNG_INFLATE_BUF_SIZE 1024
+#define PNG_LINKAGE_API extern
+#define PNG_LINKAGE_CALLBACK extern
+#define PNG_LINKAGE_DATA extern
+#define PNG_LINKAGE_FUNCTION extern
+#define PNG_MAX_GAMMA_8 11
+#define PNG_QUANTIZE_BLUE_BITS 5
+#define PNG_QUANTIZE_GREEN_BITS 5
+#define PNG_QUANTIZE_RED_BITS 5
+#define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_TEXT_Z_DEFAULT_STRATEGY 0
+#define PNG_USER_CHUNK_CACHE_MAX 1000
+#define PNG_USER_CHUNK_MALLOC_MAX 8000000
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
+#define PNG_ZBUF_SIZE 8192
+#define PNG_ZLIB_VERNUM 0 /* unknown */
+#define PNG_Z_DEFAULT_COMPRESSION (-1)
+#define PNG_Z_DEFAULT_NOFILTER_STRATEGY 0
+#define PNG_Z_DEFAULT_STRATEGY 1
+#define PNG_sCAL_PRECISION 5
+#define PNG_sRGB_PROFILE_CHECKS 2
+/* end of settings */
+#endif /* PNGLCONF_H */
diff --git a/xs/src/png/libpng/scripts/test.cmake.in b/xs/src/png/libpng/scripts/test.cmake.in
new file mode 100644
index 000000000..fa6a889bb
--- /dev/null
+++ b/xs/src/png/libpng/scripts/test.cmake.in
@@ -0,0 +1,31 @@
+# test.cmake.in
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+set(TEST_OPTIONS "@TEST_OPTIONS@")
+set(TEST_FILES "@TEST_FILES@")
+
+foreach(file ${TEST_FILES})
+  file(TO_NATIVE_PATH "${file}" native_file)
+  list(APPEND NATIVE_TEST_FILES "${native_file}")
+endforeach()
+
+# Add the directory containing libpng to the PATH (Windows only)
+if(WIN32)
+  get_filename_component(LIBPNG_DIR "${LIBPNG}" PATH)
+  file(TO_NATIVE_PATH "${LIBPNG_DIR}" LIBPNG_DIR)
+  set(ENV{PATH} "${LIBPNG_DIR};$ENV{PATH}")
+endif()
+
+execute_process(COMMAND "${CMAKE_COMMAND}" -E echo "Running ${TEST_COMMAND}" ${TEST_OPTIONS} ${NATIVE_TEST_FILES})
+
+execute_process(COMMAND "${TEST_COMMAND}" ${TEST_OPTIONS} ${NATIVE_TEST_FILES}
+                RESULT_VARIABLE TEST_STATUS)
+if(TEST_STATUS)
+  message(FATAL_ERROR "Returned failed status ${TEST_STATUS}!")
+endif()
diff --git a/xs/src/png/zlib/CMakeLists.txt b/xs/src/png/zlib/CMakeLists.txt
new file mode 100644
index 000000000..d3dad97c7
--- /dev/null
+++ b/xs/src/png/zlib/CMakeLists.txt
@@ -0,0 +1,251 @@
+cmake_minimum_required(VERSION 2.4.4)
+set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS ON)
+
+project(zlib C)
+
+set(VERSION "1.2.11")
+
+option(ASM686 "Enable building i686 assembly implementation")
+option(AMD64 "Enable building amd64 assembly implementation")
+
+set(INSTALL_BIN_DIR "${CMAKE_INSTALL_PREFIX}/bin" CACHE PATH "Installation directory for executables")
+set(INSTALL_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib" CACHE PATH "Installation directory for libraries")
+set(INSTALL_INC_DIR "${CMAKE_INSTALL_PREFIX}/include" CACHE PATH "Installation directory for headers")
+set(INSTALL_MAN_DIR "${CMAKE_INSTALL_PREFIX}/share/man" CACHE PATH "Installation directory for manual pages")
+set(INSTALL_PKGCONFIG_DIR "${CMAKE_INSTALL_PREFIX}/share/pkgconfig" CACHE PATH "Installation directory for pkgconfig (.pc) files")
+
+include(CheckTypeSize)
+include(CheckFunctionExists)
+include(CheckIncludeFile)
+include(CheckCSourceCompiles)
+#enable_testing()
+
+check_include_file(sys/types.h HAVE_SYS_TYPES_H)
+check_include_file(stdint.h    HAVE_STDINT_H)
+check_include_file(stddef.h    HAVE_STDDEF_H)
+
+#
+# Check to see if we have large file support
+#
+set(CMAKE_REQUIRED_DEFINITIONS -D_LARGEFILE64_SOURCE=1)
+# We add these other definitions here because CheckTypeSize.cmake
+# in CMake 2.4.x does not automatically do so and we want
+# compatibility with CMake 2.4.x.
+if(HAVE_SYS_TYPES_H)
+    list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_SYS_TYPES_H)
+endif()
+if(HAVE_STDINT_H)
+    list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_STDINT_H)
+endif()
+if(HAVE_STDDEF_H)
+    list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_STDDEF_H)
+endif()
+check_type_size(off64_t OFF64_T)
+if(HAVE_OFF64_T)
+   add_definitions(-D_LARGEFILE64_SOURCE=1)
+endif()
+set(CMAKE_REQUIRED_DEFINITIONS) # clear variable
+
+#
+# Check for fseeko
+#
+check_function_exists(fseeko HAVE_FSEEKO)
+if(NOT HAVE_FSEEKO)
+    add_definitions(-DNO_FSEEKO)
+endif()
+
+#
+# Check for unistd.h
+#
+check_include_file(unistd.h Z_HAVE_UNISTD_H)
+
+if(MSVC)
+    set(CMAKE_DEBUG_POSTFIX "d")
+    add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+    add_definitions(-D_CRT_NONSTDC_NO_DEPRECATE)
+    include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+endif()
+
+if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_CURRENT_BINARY_DIR)
+    # If we're doing an out of source build and the user has a zconf.h
+    # in their source tree...
+    if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/zconf.h)
+        message(STATUS "Renaming")
+        message(STATUS "    ${CMAKE_CURRENT_SOURCE_DIR}/zconf.h")
+        message(STATUS "to 'zconf.h.included' because this file is included with zlib")
+        message(STATUS "but CMake generates it automatically in the build directory.")
+        file(RENAME ${CMAKE_CURRENT_SOURCE_DIR}/zconf.h ${CMAKE_CURRENT_SOURCE_DIR}/zconf.h.included)
+  endif()
+endif()
+
+set(ZLIB_PC ${CMAKE_CURRENT_BINARY_DIR}/zlib.pc)
+configure_file( ${CMAKE_CURRENT_SOURCE_DIR}/zlib.pc.cmakein
+		${ZLIB_PC} @ONLY)
+configure_file(	${CMAKE_CURRENT_SOURCE_DIR}/zconf.h.cmakein
+		${CMAKE_CURRENT_BINARY_DIR}/zconf.h @ONLY)
+include_directories(${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_SOURCE_DIR})
+
+
+#============================================================================
+# zlib
+#============================================================================
+
+set(ZLIB_PUBLIC_HDRS
+    ${CMAKE_CURRENT_BINARY_DIR}/zconf.h
+    zlib.h
+)
+set(ZLIB_PRIVATE_HDRS
+    crc32.h
+    deflate.h
+    gzguts.h
+    inffast.h
+    inffixed.h
+    inflate.h
+    inftrees.h
+    trees.h
+    zutil.h
+)
+set(ZLIB_SRCS
+    adler32.c
+    compress.c
+    crc32.c
+    deflate.c
+    gzclose.c
+    gzlib.c
+    gzread.c
+    gzwrite.c
+    inflate.c
+    infback.c
+    inftrees.c
+    inffast.c
+    trees.c
+    uncompr.c
+    zutil.c
+)
+
+if(NOT MINGW)
+    set(ZLIB_DLL_SRCS
+        win32/zlib1.rc # If present will override custom build rule below.
+    )
+endif()
+
+if(CMAKE_COMPILER_IS_GNUCC)
+    if(ASM686)
+        set(ZLIB_ASMS contrib/asm686/match.S)
+    elseif (AMD64)
+        set(ZLIB_ASMS contrib/amd64/amd64-match.S)
+    endif ()
+
+	if(ZLIB_ASMS)
+		add_definitions(-DASMV)
+		set_source_files_properties(${ZLIB_ASMS} PROPERTIES LANGUAGE C COMPILE_FLAGS -DNO_UNDERLINE)
+	endif()
+endif()
+
+if(MSVC)
+    if(ASM686)
+		ENABLE_LANGUAGE(ASM_MASM)
+        set(ZLIB_ASMS
+			contrib/masmx86/inffas32.asm
+			contrib/masmx86/match686.asm
+		)
+    elseif (AMD64)
+		ENABLE_LANGUAGE(ASM_MASM)
+        set(ZLIB_ASMS
+			contrib/masmx64/gvmat64.asm
+			contrib/masmx64/inffasx64.asm
+		)
+    endif()
+
+	if(ZLIB_ASMS)
+		add_definitions(-DASMV -DASMINF)
+	endif()
+endif()
+
+# parse the full version number from zlib.h and include in ZLIB_FULL_VERSION
+file(READ ${CMAKE_CURRENT_SOURCE_DIR}/zlib.h _zlib_h_contents)
+string(REGEX REPLACE ".*#define[ \t]+ZLIB_VERSION[ \t]+\"([-0-9A-Za-z.]+)\".*"
+    "\\1" ZLIB_FULL_VERSION ${_zlib_h_contents})
+
+if(MINGW)
+    # This gets us DLL resource information when compiling on MinGW.
+    if(NOT CMAKE_RC_COMPILER)
+        set(CMAKE_RC_COMPILER windres.exe)
+    endif()
+
+    add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/zlib1rc.obj
+                       COMMAND ${CMAKE_RC_COMPILER}
+                            -D GCC_WINDRES
+                            -I ${CMAKE_CURRENT_SOURCE_DIR}
+                            -I ${CMAKE_CURRENT_BINARY_DIR}
+                            -o ${CMAKE_CURRENT_BINARY_DIR}/zlib1rc.obj
+                            -i ${CMAKE_CURRENT_SOURCE_DIR}/win32/zlib1.rc)
+    set(ZLIB_DLL_SRCS ${CMAKE_CURRENT_BINARY_DIR}/zlib1rc.obj)
+endif(MINGW)
+
+#add_library(zlib SHARED ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_DLL_SRCS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
+add_library(zlibstatic STATIC ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
+#set_target_properties(zlib PROPERTIES DEFINE_SYMBOL ZLIB_DLL)
+#set_target_properties(zlib PROPERTIES SOVERSION 1)
+
+if(NOT CYGWIN)
+    # This property causes shared libraries on Linux to have the full version
+    # encoded into their final filename.  We disable this on Cygwin because
+    # it causes cygz-${ZLIB_FULL_VERSION}.dll to be created when cygz.dll
+    # seems to be the default.
+    #
+    # This has no effect with MSVC, on that platform the version info for
+    # the DLL comes from the resource file win32/zlib1.rc
+#    set_target_properties(zlib PROPERTIES VERSION ${ZLIB_FULL_VERSION})
+endif()
+
+if(UNIX)
+    # On unix-like platforms the library is almost always called libz
+   set_target_properties(zlib zlibstatic PROPERTIES OUTPUT_NAME z)
+   if(NOT APPLE)
+     set_target_properties(zlib PROPERTIES LINK_FLAGS "-Wl,--version-script,\"${CMAKE_CURRENT_SOURCE_DIR}/zlib.map\"")
+   endif()
+elseif(BUILD_SHARED_LIBS AND WIN32)
+    # Creates zlib1.dll when building shared library version
+    set_target_properties(zlib PROPERTIES SUFFIX "1.dll")
+endif()
+
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+    install(TARGETS
+#            zlib
+            zlibstatic
+        RUNTIME DESTINATION "${INSTALL_BIN_DIR}"
+        ARCHIVE DESTINATION "${INSTALL_LIB_DIR}"
+        LIBRARY DESTINATION "${INSTALL_LIB_DIR}" )
+endif()
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
+    install(FILES ${ZLIB_PUBLIC_HDRS} DESTINATION "${INSTALL_INC_DIR}")
+endif()
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+    install(FILES zlib.3 DESTINATION "${INSTALL_MAN_DIR}/man3")
+endif()
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+    install(FILES ${ZLIB_PC} DESTINATION "${INSTALL_PKGCONFIG_DIR}")
+endif()
+
+#============================================================================
+# Example binaries
+#============================================================================
+
+#add_executable(example test/example.c)
+#target_link_libraries(example zlib)
+#add_test(example example)
+
+#add_executable(minigzip test/minigzip.c)
+#target_link_libraries(minigzip zlib)
+
+#if(HAVE_OFF64_T)
+#    add_executable(example64 test/example.c)
+#    target_link_libraries(example64 zlib)
+#    set_target_properties(example64 PROPERTIES COMPILE_FLAGS "-D_FILE_OFFSET_BITS=64")
+#    add_test(example64 example64)
+
+#    add_executable(minigzip64 test/minigzip.c)
+#    target_link_libraries(minigzip64 zlib)
+#    set_target_properties(minigzip64 PROPERTIES COMPILE_FLAGS "-D_FILE_OFFSET_BITS=64")
+#endif()
diff --git a/xs/src/png/zlib/ChangeLog b/xs/src/png/zlib/ChangeLog
new file mode 100644
index 000000000..30199a65a
--- /dev/null
+++ b/xs/src/png/zlib/ChangeLog
@@ -0,0 +1,1515 @@
+
+                ChangeLog file for zlib
+
+Changes in 1.2.11 (15 Jan 2017)
+- Fix deflate stored bug when pulling last block from window
+- Permit immediate deflateParams changes before any deflate input
+
+Changes in 1.2.10 (2 Jan 2017)
+- Avoid warnings on snprintf() return value
+- Fix bug in deflate_stored() for zero-length input
+- Fix bug in gzwrite.c that produced corrupt gzip files
+- Remove files to be installed before copying them in Makefile.in
+- Add warnings when compiling with assembler code
+
+Changes in 1.2.9 (31 Dec 2016)
+- Fix contrib/minizip to permit unzipping with desktop API [Zouzou]
+- Improve contrib/blast to return unused bytes
+- Assure that gzoffset() is correct when appending
+- Improve compress() and uncompress() to support large lengths
+- Fix bug in test/example.c where error code not saved
+- Remedy Coverity warning [Randers-Pehrson]
+- Improve speed of gzprintf() in transparent mode
+- Fix inflateInit2() bug when windowBits is 16 or 32
+- Change DEBUG macro to ZLIB_DEBUG
+- Avoid uninitialized access by gzclose_w()
+- Allow building zlib outside of the source directory
+- Fix bug that accepted invalid zlib header when windowBits is zero
+- Fix gzseek() problem on MinGW due to buggy _lseeki64 there
+- Loop on write() calls in gzwrite.c in case of non-blocking I/O
+- Add --warn (-w) option to ./configure for more compiler warnings
+- Reject a window size of 256 bytes if not using the zlib wrapper
+- Fix bug when level 0 used with Z_HUFFMAN or Z_RLE
+- Add --debug (-d) option to ./configure to define ZLIB_DEBUG
+- Fix bugs in creating a very large gzip header
+- Add uncompress2() function, which returns the input size used
+- Assure that deflateParams() will not switch functions mid-block
+- Dramatically speed up deflation for level 0 (storing)
+- Add gzfread(), duplicating the interface of fread()
+- Add gzfwrite(), duplicating the interface of fwrite()
+- Add deflateGetDictionary() function
+- Use snprintf() for later versions of Microsoft C
+- Fix *Init macros to use z_ prefix when requested
+- Replace as400 with os400 for OS/400 support [Monnerat]
+- Add crc32_z() and adler32_z() functions with size_t lengths
+- Update Visual Studio project files [AraHaan]
+
+Changes in 1.2.8 (28 Apr 2013)
+- Update contrib/minizip/iowin32.c for Windows RT [Vollant]
+- Do not force Z_CONST for C++
+- Clean up contrib/vstudio [Roß]
+- Correct spelling error in zlib.h
+- Fix mixed line endings in contrib/vstudio
+
+Changes in 1.2.7.3 (13 Apr 2013)
+- Fix version numbers and DLL names in contrib/vstudio/*/zlib.rc
+
+Changes in 1.2.7.2 (13 Apr 2013)
+- Change check for a four-byte type back to hexadecimal
+- Fix typo in win32/Makefile.msc
+- Add casts in gzwrite.c for pointer differences
+
+Changes in 1.2.7.1 (24 Mar 2013)
+- Replace use of unsafe string functions with snprintf if available
+- Avoid including stddef.h on Windows for Z_SOLO compile [Niessink]
+- Fix gzgetc undefine when Z_PREFIX set [Turk]
+- Eliminate use of mktemp in Makefile (not always available)
+- Fix bug in 'F' mode for gzopen()
+- Add inflateGetDictionary() function
+- Correct comment in deflate.h
+- Use _snprintf for snprintf in Microsoft C
+- On Darwin, only use /usr/bin/libtool if libtool is not Apple
+- Delete "--version" file if created by "ar --version" [Richard G.]
+- Fix configure check for veracity of compiler error return codes
+- Fix CMake compilation of static lib for MSVC2010 x64
+- Remove unused variable in infback9.c
+- Fix argument checks in gzlog_compress() and gzlog_write()
+- Clean up the usage of z_const and respect const usage within zlib
+- Clean up examples/gzlog.[ch] comparisons of different types
+- Avoid shift equal to bits in type (caused endless loop)
+- Fix uninitialized value bug in gzputc() introduced by const patches
+- Fix memory allocation error in examples/zran.c [Nor]
+- Fix bug where gzopen(), gzclose() would write an empty file
+- Fix bug in gzclose() when gzwrite() runs out of memory
+- Check for input buffer malloc failure in examples/gzappend.c
+- Add note to contrib/blast to use binary mode in stdio
+- Fix comparisons of differently signed integers in contrib/blast
+- Check for invalid code length codes in contrib/puff
+- Fix serious but very rare decompression bug in inftrees.c
+- Update inflateBack() comments, since inflate() can be faster
+- Use underscored I/O function names for WINAPI_FAMILY
+- Add _tr_flush_bits to the external symbols prefixed by --zprefix
+- Add contrib/vstudio/vc10 pre-build step for static only
+- Quote --version-script argument in CMakeLists.txt
+- Don't specify --version-script on Apple platforms in CMakeLists.txt
+- Fix casting error in contrib/testzlib/testzlib.c
+- Fix types in contrib/minizip to match result of get_crc_table()
+- Simplify contrib/vstudio/vc10 with 'd' suffix
+- Add TOP support to win32/Makefile.msc
+- Suport i686 and amd64 assembler builds in CMakeLists.txt
+- Fix typos in the use of _LARGEFILE64_SOURCE in zconf.h
+- Add vc11 and vc12 build files to contrib/vstudio
+- Add gzvprintf() as an undocumented function in zlib
+- Fix configure for Sun shell
+- Remove runtime check in configure for four-byte integer type
+- Add casts and consts to ease user conversion to C++
+- Add man pages for minizip and miniunzip
+- In Makefile uninstall, don't rm if preceding cd fails
+- Do not return Z_BUF_ERROR if deflateParam() has nothing to write
+
+Changes in 1.2.7 (2 May 2012)
+- Replace use of memmove() with a simple copy for portability
+- Test for existence of strerror
+- Restore gzgetc_ for backward compatibility with 1.2.6
+- Fix build with non-GNU make on Solaris
+- Require gcc 4.0 or later on Mac OS X to use the hidden attribute
+- Include unistd.h for Watcom C
+- Use __WATCOMC__ instead of __WATCOM__
+- Do not use the visibility attribute if NO_VIZ defined
+- Improve the detection of no hidden visibility attribute
+- Avoid using __int64 for gcc or solo compilation
+- Cast to char * in gzprintf to avoid warnings [Zinser]
+- Fix make_vms.com for VAX [Zinser]
+- Don't use library or built-in byte swaps
+- Simplify test and use of gcc hidden attribute
+- Fix bug in gzclose_w() when gzwrite() fails to allocate memory
+- Add "x" (O_EXCL) and "e" (O_CLOEXEC) modes support to gzopen()
+- Fix bug in test/minigzip.c for configure --solo
+- Fix contrib/vstudio project link errors [Mohanathas]
+- Add ability to choose the builder in make_vms.com [Schweda]
+- Add DESTDIR support to mingw32 win32/Makefile.gcc
+- Fix comments in win32/Makefile.gcc for proper usage
+- Allow overriding the default install locations for cmake
+- Generate and install the pkg-config file with cmake
+- Build both a static and a shared version of zlib with cmake
+- Include version symbols for cmake builds
+- If using cmake with MSVC, add the source directory to the includes
+- Remove unneeded EXTRA_CFLAGS from win32/Makefile.gcc [Truta]
+- Move obsolete emx makefile to old [Truta]
+- Allow the use of -Wundef when compiling or using zlib
+- Avoid the use of the -u option with mktemp
+- Improve inflate() documentation on the use of Z_FINISH
+- Recognize clang as gcc
+- Add gzopen_w() in Windows for wide character path names
+- Rename zconf.h in CMakeLists.txt to move it out of the way
+- Add source directory in CMakeLists.txt for building examples
+- Look in build directory for zlib.pc in CMakeLists.txt
+- Remove gzflags from zlibvc.def in vc9 and vc10
+- Fix contrib/minizip compilation in the MinGW environment
+- Update ./configure for Solaris, support --64 [Mooney]
+- Remove -R. from Solaris shared build (possible security issue)
+- Avoid race condition for parallel make (-j) running example
+- Fix type mismatch between get_crc_table() and crc_table
+- Fix parsing of version with "-" in CMakeLists.txt [Snider, Ziegler]
+- Fix the path to zlib.map in CMakeLists.txt
+- Force the native libtool in Mac OS X to avoid GNU libtool [Beebe]
+- Add instructions to win32/Makefile.gcc for shared install [Torri]
+
+Changes in 1.2.6.1 (12 Feb 2012)
+- Avoid the use of the Objective-C reserved name "id"
+- Include io.h in gzguts.h for Microsoft compilers
+- Fix problem with ./configure --prefix and gzgetc macro
+- Include gz_header definition when compiling zlib solo
+- Put gzflags() functionality back in zutil.c
+- Avoid library header include in crc32.c for Z_SOLO
+- Use name in GCC_CLASSIC as C compiler for coverage testing, if set
+- Minor cleanup in contrib/minizip/zip.c [Vollant]
+- Update make_vms.com [Zinser]
+- Remove unnecessary gzgetc_ function
+- Use optimized byte swap operations for Microsoft and GNU [Snyder]
+- Fix minor typo in zlib.h comments [Rzesniowiecki]
+
+Changes in 1.2.6 (29 Jan 2012)
+- Update the Pascal interface in contrib/pascal
+- Fix function numbers for gzgetc_ in zlibvc.def files
+- Fix configure.ac for contrib/minizip [Schiffer]
+- Fix large-entry detection in minizip on 64-bit systems [Schiffer]
+- Have ./configure use the compiler return code for error indication
+- Fix CMakeLists.txt for cross compilation [McClure]
+- Fix contrib/minizip/zip.c for 64-bit architectures [Dalsnes]
+- Fix compilation of contrib/minizip on FreeBSD [Marquez]
+- Correct suggested usages in win32/Makefile.msc [Shachar, Horvath]
+- Include io.h for Turbo C / Borland C on all platforms [Truta]
+- Make version explicit in contrib/minizip/configure.ac [Bosmans]
+- Avoid warning for no encryption in contrib/minizip/zip.c [Vollant]
+- Minor cleanup up contrib/minizip/unzip.c [Vollant]
+- Fix bug when compiling minizip with C++ [Vollant]
+- Protect for long name and extra fields in contrib/minizip [Vollant]
+- Avoid some warnings in contrib/minizip [Vollant]
+- Add -I../.. -L../.. to CFLAGS for minizip and miniunzip
+- Add missing libs to minizip linker command
+- Add support for VPATH builds in contrib/minizip
+- Add an --enable-demos option to contrib/minizip/configure
+- Add the generation of configure.log by ./configure
+- Exit when required parameters not provided to win32/Makefile.gcc
+- Have gzputc return the character written instead of the argument
+- Use the -m option on ldconfig for BSD systems [Tobias]
+- Correct in zlib.map when deflateResetKeep was added
+
+Changes in 1.2.5.3 (15 Jan 2012)
+- Restore gzgetc function for binary compatibility
+- Do not use _lseeki64 under Borland C++ [Truta]
+- Update win32/Makefile.msc to build test/*.c [Truta]
+- Remove old/visualc6 given CMakefile and other alternatives
+- Update AS400 build files and documentation [Monnerat]
+- Update win32/Makefile.gcc to build test/*.c [Truta]
+- Permit stronger flushes after Z_BLOCK flushes
+- Avoid extraneous empty blocks when doing empty flushes
+- Permit Z_NULL arguments to deflatePending
+- Allow deflatePrime() to insert bits in the middle of a stream
+- Remove second empty static block for Z_PARTIAL_FLUSH
+- Write out all of the available bits when using Z_BLOCK
+- Insert the first two strings in the hash table after a flush
+
+Changes in 1.2.5.2 (17 Dec 2011)
+- fix ld error: unable to find version dependency 'ZLIB_1.2.5'
+- use relative symlinks for shared libs
+- Avoid searching past window for Z_RLE strategy
+- Assure that high-water mark initialization is always applied in deflate
+- Add assertions to fill_window() in deflate.c to match comments
+- Update python link in README
+- Correct spelling error in gzread.c
+- Fix bug in gzgets() for a concatenated empty gzip stream
+- Correct error in comment for gz_make()
+- Change gzread() and related to ignore junk after gzip streams
+- Allow gzread() and related to continue after gzclearerr()
+- Allow gzrewind() and gzseek() after a premature end-of-file
+- Simplify gzseek() now that raw after gzip is ignored
+- Change gzgetc() to a macro for speed (~40% speedup in testing)
+- Fix gzclose() to return the actual error last encountered
+- Always add large file support for windows
+- Include zconf.h for windows large file support
+- Include zconf.h.cmakein for windows large file support
+- Update zconf.h.cmakein on make distclean
+- Merge vestigial vsnprintf determination from zutil.h to gzguts.h
+- Clarify how gzopen() appends in zlib.h comments
+- Correct documentation of gzdirect() since junk at end now ignored
+- Add a transparent write mode to gzopen() when 'T' is in the mode
+- Update python link in zlib man page
+- Get inffixed.h and MAKEFIXED result to match
+- Add a ./config --solo option to make zlib subset with no library use
+- Add undocumented inflateResetKeep() function for CAB file decoding
+- Add --cover option to ./configure for gcc coverage testing
+- Add #define ZLIB_CONST option to use const in the z_stream interface
+- Add comment to gzdopen() in zlib.h to use dup() when using fileno()
+- Note behavior of uncompress() to provide as much data as it can
+- Add files in contrib/minizip to aid in building libminizip
+- Split off AR options in Makefile.in and configure
+- Change ON macro to Z_ARG to avoid application conflicts
+- Facilitate compilation with Borland C++ for pragmas and vsnprintf
+- Include io.h for Turbo C / Borland C++
+- Move example.c and minigzip.c to test/
+- Simplify incomplete code table filling in inflate_table()
+- Remove code from inflate.c and infback.c that is impossible to execute
+- Test the inflate code with full coverage
+- Allow deflateSetDictionary, inflateSetDictionary at any time (in raw)
+- Add deflateResetKeep and fix inflateResetKeep to retain dictionary
+- Fix gzwrite.c to accommodate reduced memory zlib compilation
+- Have inflate() with Z_FINISH avoid the allocation of a window
+- Do not set strm->adler when doing raw inflate
+- Fix gzeof() to behave just like feof() when read is not past end of file
+- Fix bug in gzread.c when end-of-file is reached
+- Avoid use of Z_BUF_ERROR in gz* functions except for premature EOF
+- Document gzread() capability to read concurrently written files
+- Remove hard-coding of resource compiler in CMakeLists.txt [Blammo]
+
+Changes in 1.2.5.1 (10 Sep 2011)
+- Update FAQ entry on shared builds (#13)
+- Avoid symbolic argument to chmod in Makefile.in
+- Fix bug and add consts in contrib/puff [Oberhumer]
+- Update contrib/puff/zeros.raw test file to have all block types
+- Add full coverage test for puff in contrib/puff/Makefile
+- Fix static-only-build install in Makefile.in
+- Fix bug in unzGetCurrentFileInfo() in contrib/minizip [Kuno]
+- Add libz.a dependency to shared in Makefile.in for parallel builds
+- Spell out "number" (instead of "nb") in zlib.h for total_in, total_out
+- Replace $(...) with `...` in configure for non-bash sh [Bowler]
+- Add darwin* to Darwin* and solaris* to SunOS\ 5* in configure [Groffen]
+- Add solaris* to Linux* in configure to allow gcc use [Groffen]
+- Add *bsd* to Linux* case in configure [Bar-Lev]
+- Add inffast.obj to dependencies in win32/Makefile.msc
+- Correct spelling error in deflate.h [Kohler]
+- Change libzdll.a again to libz.dll.a (!) in win32/Makefile.gcc
+- Add test to configure for GNU C looking for gcc in output of $cc -v
+- Add zlib.pc generation to win32/Makefile.gcc [Weigelt]
+- Fix bug in zlib.h for _FILE_OFFSET_BITS set and _LARGEFILE64_SOURCE not
+- Add comment in zlib.h that adler32_combine with len2 < 0 makes no sense
+- Make NO_DIVIDE option in adler32.c much faster (thanks to John Reiser)
+- Make stronger test in zconf.h to include unistd.h for LFS
+- Apply Darwin patches for 64-bit file offsets to contrib/minizip [Slack]
+- Fix zlib.h LFS support when Z_PREFIX used
+- Add updated as400 support (removed from old) [Monnerat]
+- Avoid deflate sensitivity to volatile input data
+- Avoid division in adler32_combine for NO_DIVIDE
+- Clarify the use of Z_FINISH with deflateBound() amount of space
+- Set binary for output file in puff.c
+- Use u4 type for crc_table to avoid conversion warnings
+- Apply casts in zlib.h to avoid conversion warnings
+- Add OF to prototypes for adler32_combine_ and crc32_combine_ [Miller]
+- Improve inflateSync() documentation to note indeterminancy
+- Add deflatePending() function to return the amount of pending output
+- Correct the spelling of "specification" in FAQ [Randers-Pehrson]
+- Add a check in configure for stdarg.h, use for gzprintf()
+- Check that pointers fit in ints when gzprint() compiled old style
+- Add dummy name before $(SHAREDLIBV) in Makefile [Bar-Lev, Bowler]
+- Delete line in configure that adds -L. libz.a to LDFLAGS [Weigelt]
+- Add debug records in assmebler code [Londer]
+- Update RFC references to use http://tools.ietf.org/html/... [Li]
+- Add --archs option, use of libtool to configure for Mac OS X [Borstel]
+
+Changes in 1.2.5 (19 Apr 2010)
+- Disable visibility attribute in win32/Makefile.gcc [Bar-Lev]
+- Default to libdir as sharedlibdir in configure [Nieder]
+- Update copyright dates on modified source files
+- Update trees.c to be able to generate modified trees.h
+- Exit configure for MinGW, suggesting win32/Makefile.gcc
+- Check for NULL path in gz_open [Homurlu]
+
+Changes in 1.2.4.5 (18 Apr 2010)
+- Set sharedlibdir in configure [Torok]
+- Set LDFLAGS in Makefile.in [Bar-Lev]
+- Avoid mkdir objs race condition in Makefile.in [Bowler]
+- Add ZLIB_INTERNAL in front of internal inter-module functions and arrays
+- Define ZLIB_INTERNAL to hide internal functions and arrays for GNU C
+- Don't use hidden attribute when it is a warning generator (e.g. Solaris)
+
+Changes in 1.2.4.4 (18 Apr 2010)
+- Fix CROSS_PREFIX executable testing, CHOST extract, mingw* [Torok]
+- Undefine _LARGEFILE64_SOURCE in zconf.h if it is zero, but not if empty
+- Try to use bash or ksh regardless of functionality of /bin/sh
+- Fix configure incompatibility with NetBSD sh
+- Remove attempt to run under bash or ksh since have better NetBSD fix
+- Fix win32/Makefile.gcc for MinGW [Bar-Lev]
+- Add diagnostic messages when using CROSS_PREFIX in configure
+- Added --sharedlibdir option to configure [Weigelt]
+- Use hidden visibility attribute when available [Frysinger]
+
+Changes in 1.2.4.3 (10 Apr 2010)
+- Only use CROSS_PREFIX in configure for ar and ranlib if they exist
+- Use CROSS_PREFIX for nm [Bar-Lev]
+- Assume _LARGEFILE64_SOURCE defined is equivalent to true
+- Avoid use of undefined symbols in #if with && and ||
+- Make *64 prototypes in gzguts.h consistent with functions
+- Add -shared load option for MinGW in configure [Bowler]
+- Move z_off64_t to public interface, use instead of off64_t
+- Remove ! from shell test in configure (not portable to Solaris)
+- Change +0 macro tests to -0 for possibly increased portability
+
+Changes in 1.2.4.2 (9 Apr 2010)
+- Add consistent carriage returns to readme.txt's in masmx86 and masmx64
+- Really provide prototypes for *64 functions when building without LFS
+- Only define unlink() in minigzip.c if unistd.h not included
+- Update README to point to contrib/vstudio project files
+- Move projects/vc6 to old/ and remove projects/
+- Include stdlib.h in minigzip.c for setmode() definition under WinCE
+- Clean up assembler builds in win32/Makefile.msc [Rowe]
+- Include sys/types.h for Microsoft for off_t definition
+- Fix memory leak on error in gz_open()
+- Symbolize nm as $NM in configure [Weigelt]
+- Use TEST_LDSHARED instead of LDSHARED to link test programs [Weigelt]
+- Add +0 to _FILE_OFFSET_BITS and _LFS64_LARGEFILE in case not defined
+- Fix bug in gzeof() to take into account unused input data
+- Avoid initialization of structures with variables in puff.c
+- Updated win32/README-WIN32.txt [Rowe]
+
+Changes in 1.2.4.1 (28 Mar 2010)
+- Remove the use of [a-z] constructs for sed in configure [gentoo 310225]
+- Remove $(SHAREDLIB) from LIBS in Makefile.in [Creech]
+- Restore "for debugging" comment on sprintf() in gzlib.c
+- Remove fdopen for MVS from gzguts.h
+- Put new README-WIN32.txt in win32 [Rowe]
+- Add check for shell to configure and invoke another shell if needed
+- Fix big fat stinking bug in gzseek() on uncompressed files
+- Remove vestigial F_OPEN64 define in zutil.h
+- Set and check the value of _LARGEFILE_SOURCE and _LARGEFILE64_SOURCE
+- Avoid errors on non-LFS systems when applications define LFS macros
+- Set EXE to ".exe" in configure for MINGW [Kahle]
+- Match crc32() in crc32.c exactly to the prototype in zlib.h [Sherrill]
+- Add prefix for cross-compilation in win32/makefile.gcc [Bar-Lev]
+- Add DLL install in win32/makefile.gcc [Bar-Lev]
+- Allow Linux* or linux* from uname in configure [Bar-Lev]
+- Allow ldconfig to be redefined in configure and Makefile.in [Bar-Lev]
+- Add cross-compilation prefixes to configure [Bar-Lev]
+- Match type exactly in gz_load() invocation in gzread.c
+- Match type exactly of zcalloc() in zutil.c to zlib.h alloc_func
+- Provide prototypes for *64 functions when building zlib without LFS
+- Don't use -lc when linking shared library on MinGW
+- Remove errno.h check in configure and vestigial errno code in zutil.h
+
+Changes in 1.2.4 (14 Mar 2010)
+- Fix VER3 extraction in configure for no fourth subversion
+- Update zlib.3, add docs to Makefile.in to make .pdf out of it
+- Add zlib.3.pdf to distribution
+- Don't set error code in gzerror() if passed pointer is NULL
+- Apply destination directory fixes to CMakeLists.txt [Lowman]
+- Move #cmakedefine's to a new zconf.in.cmakein
+- Restore zconf.h for builds that don't use configure or cmake
+- Add distclean to dummy Makefile for convenience
+- Update and improve INDEX, README, and FAQ
+- Update CMakeLists.txt for the return of zconf.h [Lowman]
+- Update contrib/vstudio/vc9 and vc10 [Vollant]
+- Change libz.dll.a back to libzdll.a in win32/Makefile.gcc
+- Apply license and readme changes to contrib/asm686 [Raiter]
+- Check file name lengths and add -c option in minigzip.c [Li]
+- Update contrib/amd64 and contrib/masmx86/ [Vollant]
+- Avoid use of "eof" parameter in trees.c to not shadow library variable
+- Update make_vms.com for removal of zlibdefs.h [Zinser]
+- Update assembler code and vstudio projects in contrib [Vollant]
+- Remove outdated assembler code contrib/masm686 and contrib/asm586
+- Remove old vc7 and vc8 from contrib/vstudio
+- Update win32/Makefile.msc, add ZLIB_VER_SUBREVISION [Rowe]
+- Fix memory leaks in gzclose_r() and gzclose_w(), file leak in gz_open()
+- Add contrib/gcc_gvmat64 for longest_match and inflate_fast [Vollant]
+- Remove *64 functions from win32/zlib.def (they're not 64-bit yet)
+- Fix bug in void-returning vsprintf() case in gzwrite.c
+- Fix name change from inflate.h in contrib/inflate86/inffas86.c
+- Check if temporary file exists before removing in make_vms.com [Zinser]
+- Fix make install and uninstall for --static option
+- Fix usage of _MSC_VER in gzguts.h and zutil.h [Truta]
+- Update readme.txt in contrib/masmx64 and masmx86 to assemble
+
+Changes in 1.2.3.9 (21 Feb 2010)
+- Expunge gzio.c
+- Move as400 build information to old
+- Fix updates in contrib/minizip and contrib/vstudio
+- Add const to vsnprintf test in configure to avoid warnings [Weigelt]
+- Delete zconf.h (made by configure) [Weigelt]
+- Change zconf.in.h to zconf.h.in per convention [Weigelt]
+- Check for NULL buf in gzgets()
+- Return empty string for gzgets() with len == 1 (like fgets())
+- Fix description of gzgets() in zlib.h for end-of-file, NULL return
+- Update minizip to 1.1 [Vollant]
+- Avoid MSVC loss of data warnings in gzread.c, gzwrite.c
+- Note in zlib.h that gzerror() should be used to distinguish from EOF
+- Remove use of snprintf() from gzlib.c
+- Fix bug in gzseek()
+- Update contrib/vstudio, adding vc9 and vc10 [Kuno, Vollant]
+- Fix zconf.h generation in CMakeLists.txt [Lowman]
+- Improve comments in zconf.h where modified by configure
+
+Changes in 1.2.3.8 (13 Feb 2010)
+- Clean up text files (tabs, trailing whitespace, etc.) [Oberhumer]
+- Use z_off64_t in gz_zero() and gz_skip() to match state->skip
+- Avoid comparison problem when sizeof(int) == sizeof(z_off64_t)
+- Revert to Makefile.in from 1.2.3.6 (live with the clutter)
+- Fix missing error return in gzflush(), add zlib.h note
+- Add *64 functions to zlib.map [Levin]
+- Fix signed/unsigned comparison in gz_comp()
+- Use SFLAGS when testing shared linking in configure
+- Add --64 option to ./configure to use -m64 with gcc
+- Fix ./configure --help to correctly name options
+- Have make fail if a test fails [Levin]
+- Avoid buffer overrun in contrib/masmx64/gvmat64.asm [Simpson]
+- Remove assembler object files from contrib
+
+Changes in 1.2.3.7 (24 Jan 2010)
+- Always gzopen() with O_LARGEFILE if available
+- Fix gzdirect() to work immediately after gzopen() or gzdopen()
+- Make gzdirect() more precise when the state changes while reading
+- Improve zlib.h documentation in many places
+- Catch memory allocation failure in gz_open()
+- Complete close operation if seek forward in gzclose_w() fails
+- Return Z_ERRNO from gzclose_r() if close() fails
+- Return Z_STREAM_ERROR instead of EOF for gzclose() being passed NULL
+- Return zero for gzwrite() errors to match zlib.h description
+- Return -1 on gzputs() error to match zlib.h description
+- Add zconf.in.h to allow recovery from configure modification [Weigelt]
+- Fix static library permissions in Makefile.in [Weigelt]
+- Avoid warnings in configure tests that hide functionality [Weigelt]
+- Add *BSD and DragonFly to Linux case in configure [gentoo 123571]
+- Change libzdll.a to libz.dll.a in win32/Makefile.gcc [gentoo 288212]
+- Avoid access of uninitialized data for first inflateReset2 call [Gomes]
+- Keep object files in subdirectories to reduce the clutter somewhat
+- Remove default Makefile and zlibdefs.h, add dummy Makefile
+- Add new external functions to Z_PREFIX, remove duplicates, z_z_ -> z_
+- Remove zlibdefs.h completely -- modify zconf.h instead
+
+Changes in 1.2.3.6 (17 Jan 2010)
+- Avoid void * arithmetic in gzread.c and gzwrite.c
+- Make compilers happier with const char * for gz_error message
+- Avoid unused parameter warning in inflate.c
+- Avoid signed-unsigned comparison warning in inflate.c
+- Indent #pragma's for traditional C
+- Fix usage of strwinerror() in glib.c, change to gz_strwinerror()
+- Correct email address in configure for system options
+- Update make_vms.com and add make_vms.com to contrib/minizip [Zinser]
+- Update zlib.map [Brown]
+- Fix Makefile.in for Solaris 10 make of example64 and minizip64 [Torok]
+- Apply various fixes to CMakeLists.txt [Lowman]
+- Add checks on len in gzread() and gzwrite()
+- Add error message for no more room for gzungetc()
+- Remove zlib version check in gzwrite()
+- Defer compression of gzprintf() result until need to
+- Use snprintf() in gzdopen() if available
+- Remove USE_MMAP configuration determination (only used by minigzip)
+- Remove examples/pigz.c (available separately)
+- Update examples/gun.c to 1.6
+
+Changes in 1.2.3.5 (8 Jan 2010)
+- Add space after #if in zutil.h for some compilers
+- Fix relatively harmless bug in deflate_fast() [Exarevsky]
+- Fix same problem in deflate_slow()
+- Add $(SHAREDLIBV) to LIBS in Makefile.in [Brown]
+- Add deflate_rle() for faster Z_RLE strategy run-length encoding
+- Add deflate_huff() for faster Z_HUFFMAN_ONLY encoding
+- Change name of "write" variable in inffast.c to avoid library collisions
+- Fix premature EOF from gzread() in gzio.c [Brown]
+- Use zlib header window size if windowBits is 0 in inflateInit2()
+- Remove compressBound() call in deflate.c to avoid linking compress.o
+- Replace use of errno in gz* with functions, support WinCE [Alves]
+- Provide alternative to perror() in minigzip.c for WinCE [Alves]
+- Don't use _vsnprintf on later versions of MSVC [Lowman]
+- Add CMake build script and input file [Lowman]
+- Update contrib/minizip to 1.1 [Svensson, Vollant]
+- Moved nintendods directory from contrib to .
+- Replace gzio.c with a new set of routines with the same functionality
+- Add gzbuffer(), gzoffset(), gzclose_r(), gzclose_w() as part of above
+- Update contrib/minizip to 1.1b
+- Change gzeof() to return 0 on error instead of -1 to agree with zlib.h
+
+Changes in 1.2.3.4 (21 Dec 2009)
+- Use old school .SUFFIXES in Makefile.in for FreeBSD compatibility
+- Update comments in configure and Makefile.in for default --shared
+- Fix test -z's in configure [Marquess]
+- Build examplesh and minigzipsh when not testing
+- Change NULL's to Z_NULL's in deflate.c and in comments in zlib.h
+- Import LDFLAGS from the environment in configure
+- Fix configure to populate SFLAGS with discovered CFLAGS options
+- Adapt make_vms.com to the new Makefile.in [Zinser]
+- Add zlib2ansi script for C++ compilation [Marquess]
+- Add _FILE_OFFSET_BITS=64 test to make test (when applicable)
+- Add AMD64 assembler code for longest match to contrib [Teterin]
+- Include options from $SFLAGS when doing $LDSHARED
+- Simplify 64-bit file support by introducing z_off64_t type
+- Make shared object files in objs directory to work around old Sun cc
+- Use only three-part version number for Darwin shared compiles
+- Add rc option to ar in Makefile.in for when ./configure not run
+- Add -WI,-rpath,. to LDFLAGS for OSF 1 V4*
+- Set LD_LIBRARYN32_PATH for SGI IRIX shared compile
+- Protect against _FILE_OFFSET_BITS being defined when compiling zlib
+- Rename Makefile.in targets allstatic to static and allshared to shared
+- Fix static and shared Makefile.in targets to be independent
+- Correct error return bug in gz_open() by setting state [Brown]
+- Put spaces before ;;'s in configure for better sh compatibility
+- Add pigz.c (parallel implementation of gzip) to examples/
+- Correct constant in crc32.c to UL [Leventhal]
+- Reject negative lengths in crc32_combine()
+- Add inflateReset2() function to work like inflateEnd()/inflateInit2()
+- Include sys/types.h for _LARGEFILE64_SOURCE [Brown]
+- Correct typo in doc/algorithm.txt [Janik]
+- Fix bug in adler32_combine() [Zhu]
+- Catch missing-end-of-block-code error in all inflates and in puff
+    Assures that random input to inflate eventually results in an error
+- Added enough.c (calculation of ENOUGH for inftrees.h) to examples/
+- Update ENOUGH and its usage to reflect discovered bounds
+- Fix gzerror() error report on empty input file [Brown]
+- Add ush casts in trees.c to avoid pedantic runtime errors
+- Fix typo in zlib.h uncompress() description [Reiss]
+- Correct inflate() comments with regard to automatic header detection
+- Remove deprecation comment on Z_PARTIAL_FLUSH (it stays)
+- Put new version of gzlog (2.0) in examples with interruption recovery
+- Add puff compile option to permit invalid distance-too-far streams
+- Add puff TEST command options, ability to read piped input
+- Prototype the *64 functions in zlib.h when _FILE_OFFSET_BITS == 64, but
+  _LARGEFILE64_SOURCE not defined
+- Fix Z_FULL_FLUSH to truly erase the past by resetting s->strstart
+- Fix deflateSetDictionary() to use all 32K for output consistency
+- Remove extraneous #define MIN_LOOKAHEAD in deflate.c (in deflate.h)
+- Clear bytes after deflate lookahead to avoid use of uninitialized data
+- Change a limit in inftrees.c to be more transparent to Coverity Prevent
+- Update win32/zlib.def with exported symbols from zlib.h
+- Correct spelling errors in zlib.h [Willem, Sobrado]
+- Allow Z_BLOCK for deflate() to force a new block
+- Allow negative bits in inflatePrime() to delete existing bit buffer
+- Add Z_TREES flush option to inflate() to return at end of trees
+- Add inflateMark() to return current state information for random access
+- Add Makefile for NintendoDS to contrib [Costa]
+- Add -w in configure compile tests to avoid spurious warnings [Beucler]
+- Fix typos in zlib.h comments for deflateSetDictionary()
+- Fix EOF detection in transparent gzread() [Maier]
+
+Changes in 1.2.3.3 (2 October 2006)
+- Make --shared the default for configure, add a --static option
+- Add compile option to permit invalid distance-too-far streams
+- Add inflateUndermine() function which is required to enable above
+- Remove use of "this" variable name for C++ compatibility [Marquess]
+- Add testing of shared library in make test, if shared library built
+- Use ftello() and fseeko() if available instead of ftell() and fseek()
+- Provide two versions of all functions that use the z_off_t type for
+  binary compatibility -- a normal version and a 64-bit offset version,
+  per the Large File Support Extension when _LARGEFILE64_SOURCE is
+  defined; use the 64-bit versions by default when _FILE_OFFSET_BITS
+  is defined to be 64
+- Add a --uname= option to configure to perhaps help with cross-compiling
+
+Changes in 1.2.3.2 (3 September 2006)
+- Turn off silly Borland warnings [Hay]
+- Use off64_t and define _LARGEFILE64_SOURCE when present
+- Fix missing dependency on inffixed.h in Makefile.in
+- Rig configure --shared to build both shared and static [Teredesai, Truta]
+- Remove zconf.in.h and instead create a new zlibdefs.h file
+- Fix contrib/minizip/unzip.c non-encrypted after encrypted [Vollant]
+- Add treebuild.xml (see http://treebuild.metux.de/) [Weigelt]
+
+Changes in 1.2.3.1 (16 August 2006)
+- Add watcom directory with OpenWatcom make files [Daniel]
+- Remove #undef of FAR in zconf.in.h for MVS [Fedtke]
+- Update make_vms.com [Zinser]
+- Use -fPIC for shared build in configure [Teredesai, Nicholson]
+- Use only major version number for libz.so on IRIX and OSF1 [Reinholdtsen]
+- Use fdopen() (not _fdopen()) for Interix in zutil.h [Bäck]
+- Add some FAQ entries about the contrib directory
+- Update the MVS question in the FAQ
+- Avoid extraneous reads after EOF in gzio.c [Brown]
+- Correct spelling of "successfully" in gzio.c [Randers-Pehrson]
+- Add comments to zlib.h about gzerror() usage [Brown]
+- Set extra flags in gzip header in gzopen() like deflate() does
+- Make configure options more compatible with double-dash conventions
+  [Weigelt]
+- Clean up compilation under Solaris SunStudio cc [Rowe, Reinholdtsen]
+- Fix uninstall target in Makefile.in [Truta]
+- Add pkgconfig support [Weigelt]
+- Use $(DESTDIR) macro in Makefile.in [Reinholdtsen, Weigelt]
+- Replace set_data_type() with a more accurate detect_data_type() in
+  trees.c, according to the txtvsbin.txt document [Truta]
+- Swap the order of #include <stdio.h> and #include "zlib.h" in
+  gzio.c, example.c and minigzip.c [Truta]
+- Shut up annoying VS2005 warnings about standard C deprecation [Rowe,
+  Truta] (where?)
+- Fix target "clean" from win32/Makefile.bor [Truta]
+- Create .pdb and .manifest files in win32/makefile.msc [Ziegler, Rowe]
+- Update zlib www home address in win32/DLL_FAQ.txt [Truta]
+- Update contrib/masmx86/inffas32.asm for VS2005 [Vollant, Van Wassenhove]
+- Enable browse info in the "Debug" and "ASM Debug" configurations in
+  the Visual C++ 6 project, and set (non-ASM) "Debug" as default [Truta]
+- Add pkgconfig support [Weigelt]
+- Add ZLIB_VER_MAJOR, ZLIB_VER_MINOR and ZLIB_VER_REVISION in zlib.h,
+  for use in win32/zlib1.rc [Polushin, Rowe, Truta]
+- Add a document that explains the new text detection scheme to
+  doc/txtvsbin.txt [Truta]
+- Add rfc1950.txt, rfc1951.txt and rfc1952.txt to doc/ [Truta]
+- Move algorithm.txt into doc/ [Truta]
+- Synchronize FAQ with website
+- Fix compressBound(), was low for some pathological cases [Fearnley]
+- Take into account wrapper variations in deflateBound()
+- Set examples/zpipe.c input and output to binary mode for Windows
+- Update examples/zlib_how.html with new zpipe.c (also web site)
+- Fix some warnings in examples/gzlog.c and examples/zran.c (it seems
+  that gcc became pickier in 4.0)
+- Add zlib.map for Linux: "All symbols from zlib-1.1.4 remain
+  un-versioned, the patch adds versioning only for symbols introduced in
+  zlib-1.2.0 or later.  It also declares as local those symbols which are
+  not designed to be exported." [Levin]
+- Update Z_PREFIX list in zconf.in.h, add --zprefix option to configure
+- Do not initialize global static by default in trees.c, add a response
+  NO_INIT_GLOBAL_POINTERS to initialize them if needed [Marquess]
+- Don't use strerror() in gzio.c under WinCE [Yakimov]
+- Don't use errno.h in zutil.h under WinCE [Yakimov]
+- Move arguments for AR to its usage to allow replacing ar [Marot]
+- Add HAVE_VISIBILITY_PRAGMA in zconf.in.h for Mozilla [Randers-Pehrson]
+- Improve inflateInit() and inflateInit2() documentation
+- Fix structure size comment in inflate.h
+- Change configure help option from --h* to --help [Santos]
+
+Changes in 1.2.3 (18 July 2005)
+- Apply security vulnerability fixes to contrib/infback9 as well
+- Clean up some text files (carriage returns, trailing space)
+- Update testzlib, vstudio, masmx64, and masmx86 in contrib [Vollant]
+
+Changes in 1.2.2.4 (11 July 2005)
+- Add inflatePrime() function for starting inflation at bit boundary
+- Avoid some Visual C warnings in deflate.c
+- Avoid more silly Visual C warnings in inflate.c and inftrees.c for 64-bit
+  compile
+- Fix some spelling errors in comments [Betts]
+- Correct inflateInit2() error return documentation in zlib.h
+- Add zran.c example of compressed data random access to examples
+  directory, shows use of inflatePrime()
+- Fix cast for assignments to strm->state in inflate.c and infback.c
+- Fix zlibCompileFlags() in zutil.c to use 1L for long shifts [Oberhumer]
+- Move declarations of gf2 functions to right place in crc32.c [Oberhumer]
+- Add cast in trees.c t avoid a warning [Oberhumer]
+- Avoid some warnings in fitblk.c, gun.c, gzjoin.c in examples [Oberhumer]
+- Update make_vms.com [Zinser]
+- Initialize state->write in inflateReset() since copied in inflate_fast()
+- Be more strict on incomplete code sets in inflate_table() and increase
+  ENOUGH and MAXD -- this repairs a possible security vulnerability for
+  invalid inflate input.  Thanks to Tavis Ormandy and Markus Oberhumer for
+  discovering the vulnerability and providing test cases.
+- Add ia64 support to configure for HP-UX [Smith]
+- Add error return to gzread() for format or i/o error [Levin]
+- Use malloc.h for OS/2 [Necasek]
+
+Changes in 1.2.2.3 (27 May 2005)
+- Replace 1U constants in inflate.c and inftrees.c for 64-bit compile
+- Typecast fread() return values in gzio.c [Vollant]
+- Remove trailing space in minigzip.c outmode (VC++ can't deal with it)
+- Fix crc check bug in gzread() after gzungetc() [Heiner]
+- Add the deflateTune() function to adjust internal compression parameters
+- Add a fast gzip decompressor, gun.c, to examples (use of inflateBack)
+- Remove an incorrect assertion in examples/zpipe.c
+- Add C++ wrapper in infback9.h [Donais]
+- Fix bug in inflateCopy() when decoding fixed codes
+- Note in zlib.h how much deflateSetDictionary() actually uses
+- Remove USE_DICT_HEAD in deflate.c (would mess up inflate if used)
+- Add _WIN32_WCE to define WIN32 in zconf.in.h [Spencer]
+- Don't include stderr.h or errno.h for _WIN32_WCE in zutil.h [Spencer]
+- Add gzdirect() function to indicate transparent reads
+- Update contrib/minizip [Vollant]
+- Fix compilation of deflate.c when both ASMV and FASTEST [Oberhumer]
+- Add casts in crc32.c to avoid warnings [Oberhumer]
+- Add contrib/masmx64 [Vollant]
+- Update contrib/asm586, asm686, masmx86, testzlib, vstudio [Vollant]
+
+Changes in 1.2.2.2 (30 December 2004)
+- Replace structure assignments in deflate.c and inflate.c with zmemcpy to
+  avoid implicit memcpy calls (portability for no-library compilation)
+- Increase sprintf() buffer size in gzdopen() to allow for large numbers
+- Add INFLATE_STRICT to check distances against zlib header
+- Improve WinCE errno handling and comments [Chang]
+- Remove comment about no gzip header processing in FAQ
+- Add Z_FIXED strategy option to deflateInit2() to force fixed trees
+- Add updated make_vms.com [Coghlan], update README
+- Create a new "examples" directory, move gzappend.c there, add zpipe.c,
+  fitblk.c, gzlog.[ch], gzjoin.c, and zlib_how.html.
+- Add FAQ entry and comments in deflate.c on uninitialized memory access
+- Add Solaris 9 make options in configure [Gilbert]
+- Allow strerror() usage in gzio.c for STDC
+- Fix DecompressBuf in contrib/delphi/ZLib.pas [ManChesTer]
+- Update contrib/masmx86/inffas32.asm and gvmat32.asm [Vollant]
+- Use z_off_t for adler32_combine() and crc32_combine() lengths
+- Make adler32() much faster for small len
+- Use OS_CODE in deflate() default gzip header
+
+Changes in 1.2.2.1 (31 October 2004)
+- Allow inflateSetDictionary() call for raw inflate
+- Fix inflate header crc check bug for file names and comments
+- Add deflateSetHeader() and gz_header structure for custom gzip headers
+- Add inflateGetheader() to retrieve gzip headers
+- Add crc32_combine() and adler32_combine() functions
+- Add alloc_func, free_func, in_func, out_func to Z_PREFIX list
+- Use zstreamp consistently in zlib.h (inflate_back functions)
+- Remove GUNZIP condition from definition of inflate_mode in inflate.h
+  and in contrib/inflate86/inffast.S [Truta, Anderson]
+- Add support for AMD64 in contrib/inflate86/inffas86.c [Anderson]
+- Update projects/README.projects and projects/visualc6 [Truta]
+- Update win32/DLL_FAQ.txt [Truta]
+- Avoid warning under NO_GZCOMPRESS in gzio.c; fix typo [Truta]
+- Deprecate Z_ASCII; use Z_TEXT instead [Truta]
+- Use a new algorithm for setting strm->data_type in trees.c [Truta]
+- Do not define an exit() prototype in zutil.c unless DEBUG defined
+- Remove prototype of exit() from zutil.c, example.c, minigzip.c [Truta]
+- Add comment in zlib.h for Z_NO_FLUSH parameter to deflate()
+- Fix Darwin build version identification [Peterson]
+
+Changes in 1.2.2 (3 October 2004)
+- Update zlib.h comments on gzip in-memory processing
+- Set adler to 1 in inflateReset() to support Java test suite [Walles]
+- Add contrib/dotzlib [Ravn]
+- Update win32/DLL_FAQ.txt [Truta]
+- Update contrib/minizip [Vollant]
+- Move contrib/visual-basic.txt to old/ [Truta]
+- Fix assembler builds in projects/visualc6/ [Truta]
+
+Changes in 1.2.1.2 (9 September 2004)
+- Update INDEX file
+- Fix trees.c to update strm->data_type (no one ever noticed!)
+- Fix bug in error case in inflate.c, infback.c, and infback9.c [Brown]
+- Add "volatile" to crc table flag declaration (for DYNAMIC_CRC_TABLE)
+- Add limited multitasking protection to DYNAMIC_CRC_TABLE
+- Add NO_vsnprintf for VMS in zutil.h [Mozilla]
+- Don't declare strerror() under VMS [Mozilla]
+- Add comment to DYNAMIC_CRC_TABLE to use get_crc_table() to initialize
+- Update contrib/ada [Anisimkov]
+- Update contrib/minizip [Vollant]
+- Fix configure to not hardcode directories for Darwin [Peterson]
+- Fix gzio.c to not return error on empty files [Brown]
+- Fix indentation; update version in contrib/delphi/ZLib.pas and
+  contrib/pascal/zlibpas.pas [Truta]
+- Update mkasm.bat in contrib/masmx86 [Truta]
+- Update contrib/untgz [Truta]
+- Add projects/README.projects [Truta]
+- Add project for MS Visual C++ 6.0 in projects/visualc6 [Cadieux, Truta]
+- Update win32/DLL_FAQ.txt [Truta]
+- Update list of Z_PREFIX symbols in zconf.h [Randers-Pehrson, Truta]
+- Remove an unnecessary assignment to curr in inftrees.c [Truta]
+- Add OS/2 to exe builds in configure [Poltorak]
+- Remove err dummy parameter in zlib.h [Kientzle]
+
+Changes in 1.2.1.1 (9 January 2004)
+- Update email address in README
+- Several FAQ updates
+- Fix a big fat bug in inftrees.c that prevented decoding valid
+  dynamic blocks with only literals and no distance codes --
+  Thanks to "Hot Emu" for the bug report and sample file
+- Add a note to puff.c on no distance codes case.
+
+Changes in 1.2.1 (17 November 2003)
+- Remove a tab in contrib/gzappend/gzappend.c
+- Update some interfaces in contrib for new zlib functions
+- Update zlib version number in some contrib entries
+- Add Windows CE definition for ptrdiff_t in zutil.h [Mai, Truta]
+- Support shared libraries on Hurd and KFreeBSD [Brown]
+- Fix error in NO_DIVIDE option of adler32.c
+
+Changes in 1.2.0.8 (4 November 2003)
+- Update version in contrib/delphi/ZLib.pas and contrib/pascal/zlibpas.pas
+- Add experimental NO_DIVIDE #define in adler32.c
+    - Possibly faster on some processors (let me know if it is)
+- Correct Z_BLOCK to not return on first inflate call if no wrap
+- Fix strm->data_type on inflate() return to correctly indicate EOB
+- Add deflatePrime() function for appending in the middle of a byte
+- Add contrib/gzappend for an example of appending to a stream
+- Update win32/DLL_FAQ.txt [Truta]
+- Delete Turbo C comment in README [Truta]
+- Improve some indentation in zconf.h [Truta]
+- Fix infinite loop on bad input in configure script [Church]
+- Fix gzeof() for concatenated gzip files [Johnson]
+- Add example to contrib/visual-basic.txt [Michael B.]
+- Add -p to mkdir's in Makefile.in [vda]
+- Fix configure to properly detect presence or lack of printf functions
+- Add AS400 support [Monnerat]
+- Add a little Cygwin support [Wilson]
+
+Changes in 1.2.0.7 (21 September 2003)
+- Correct some debug formats in contrib/infback9
+- Cast a type in a debug statement in trees.c
+- Change search and replace delimiter in configure from % to # [Beebe]
+- Update contrib/untgz to 0.2 with various fixes [Truta]
+- Add build support for Amiga [Nikl]
+- Remove some directories in old that have been updated to 1.2
+- Add dylib building for Mac OS X in configure and Makefile.in
+- Remove old distribution stuff from Makefile
+- Update README to point to DLL_FAQ.txt, and add comment on Mac OS X
+- Update links in README
+
+Changes in 1.2.0.6 (13 September 2003)
+- Minor FAQ updates
+- Update contrib/minizip to 1.00 [Vollant]
+- Remove test of gz functions in example.c when GZ_COMPRESS defined [Truta]
+- Update POSTINC comment for 68060 [Nikl]
+- Add contrib/infback9 with deflate64 decoding (unsupported)
+- For MVS define NO_vsnprintf and undefine FAR [van Burik]
+- Add pragma for fdopen on MVS [van Burik]
+
+Changes in 1.2.0.5 (8 September 2003)
+- Add OF to inflateBackEnd() declaration in zlib.h
+- Remember start when using gzdopen in the middle of a file
+- Use internal off_t counters in gz* functions to properly handle seeks
+- Perform more rigorous check for distance-too-far in inffast.c
+- Add Z_BLOCK flush option to return from inflate at block boundary
+- Set strm->data_type on return from inflate
+    - Indicate bits unused, if at block boundary, and if in last block
+- Replace size_t with ptrdiff_t in crc32.c, and check for correct size
+- Add condition so old NO_DEFLATE define still works for compatibility
+- FAQ update regarding the Windows DLL [Truta]
+- INDEX update: add qnx entry, remove aix entry [Truta]
+- Install zlib.3 into mandir [Wilson]
+- Move contrib/zlib_dll_FAQ.txt to win32/DLL_FAQ.txt; update [Truta]
+- Adapt the zlib interface to the new DLL convention guidelines [Truta]
+- Introduce ZLIB_WINAPI macro to allow the export of functions using
+  the WINAPI calling convention, for Visual Basic [Vollant, Truta]
+- Update msdos and win32 scripts and makefiles [Truta]
+- Export symbols by name, not by ordinal, in win32/zlib.def [Truta]
+- Add contrib/ada [Anisimkov]
+- Move asm files from contrib/vstudio/vc70_32 to contrib/asm386 [Truta]
+- Rename contrib/asm386 to contrib/masmx86 [Truta, Vollant]
+- Add contrib/masm686 [Truta]
+- Fix offsets in contrib/inflate86 and contrib/masmx86/inffas32.asm
+  [Truta, Vollant]
+- Update contrib/delphi; rename to contrib/pascal; add example [Truta]
+- Remove contrib/delphi2; add a new contrib/delphi [Truta]
+- Avoid inclusion of the nonstandard <memory.h> in contrib/iostream,
+  and fix some method prototypes [Truta]
+- Fix the ZCR_SEED2 constant to avoid warnings in contrib/minizip
+  [Truta]
+- Avoid the use of backslash (\) in contrib/minizip [Vollant]
+- Fix file time handling in contrib/untgz; update makefiles [Truta]
+- Update contrib/vstudio/vc70_32 to comply with the new DLL guidelines
+  [Vollant]
+- Remove contrib/vstudio/vc15_16 [Vollant]
+- Rename contrib/vstudio/vc70_32 to contrib/vstudio/vc7 [Truta]
+- Update README.contrib [Truta]
+- Invert the assignment order of match_head and s->prev[...] in
+  INSERT_STRING [Truta]
+- Compare TOO_FAR with 32767 instead of 32768, to avoid 16-bit warnings
+  [Truta]
+- Compare function pointers with 0, not with NULL or Z_NULL [Truta]
+- Fix prototype of syncsearch in inflate.c [Truta]
+- Introduce ASMINF macro to be enabled when using an ASM implementation
+  of inflate_fast [Truta]
+- Change NO_DEFLATE to NO_GZCOMPRESS [Truta]
+- Modify test_gzio in example.c to take a single file name as a
+  parameter [Truta]
+- Exit the example.c program if gzopen fails [Truta]
+- Add type casts around strlen in example.c [Truta]
+- Remove casting to sizeof in minigzip.c; give a proper type
+  to the variable compared with SUFFIX_LEN [Truta]
+- Update definitions of STDC and STDC99 in zconf.h [Truta]
+- Synchronize zconf.h with the new Windows DLL interface [Truta]
+- Use SYS16BIT instead of __32BIT__ to distinguish between
+  16- and 32-bit platforms [Truta]
+- Use far memory allocators in small 16-bit memory models for
+  Turbo C [Truta]
+- Add info about the use of ASMV, ASMINF and ZLIB_WINAPI in
+  zlibCompileFlags [Truta]
+- Cygwin has vsnprintf [Wilson]
+- In Windows16, OS_CODE is 0, as in MSDOS [Truta]
+- In Cygwin, OS_CODE is 3 (Unix), not 11 (Windows32) [Wilson]
+
+Changes in 1.2.0.4 (10 August 2003)
+- Minor FAQ updates
+- Be more strict when checking inflateInit2's windowBits parameter
+- Change NO_GUNZIP compile option to NO_GZIP to cover deflate as well
+- Add gzip wrapper option to deflateInit2 using windowBits
+- Add updated QNX rule in configure and qnx directory [Bonnefoy]
+- Make inflate distance-too-far checks more rigorous
+- Clean up FAR usage in inflate
+- Add casting to sizeof() in gzio.c and minigzip.c
+
+Changes in 1.2.0.3 (19 July 2003)
+- Fix silly error in gzungetc() implementation [Vollant]
+- Update contrib/minizip and contrib/vstudio [Vollant]
+- Fix printf format in example.c
+- Correct cdecl support in zconf.in.h [Anisimkov]
+- Minor FAQ updates
+
+Changes in 1.2.0.2 (13 July 2003)
+- Add ZLIB_VERNUM in zlib.h for numerical preprocessor comparisons
+- Attempt to avoid warnings in crc32.c for pointer-int conversion
+- Add AIX to configure, remove aix directory [Bakker]
+- Add some casts to minigzip.c
+- Improve checking after insecure sprintf() or vsprintf() calls
+- Remove #elif's from crc32.c
+- Change leave label to inf_leave in inflate.c and infback.c to avoid
+  library conflicts
+- Remove inflate gzip decoding by default--only enable gzip decoding by
+  special request for stricter backward compatibility
+- Add zlibCompileFlags() function to return compilation information
+- More typecasting in deflate.c to avoid warnings
+- Remove leading underscore from _Capital #defines [Truta]
+- Fix configure to link shared library when testing
+- Add some Windows CE target adjustments [Mai]
+- Remove #define ZLIB_DLL in zconf.h [Vollant]
+- Add zlib.3 [Rodgers]
+- Update RFC URL in deflate.c and algorithm.txt [Mai]
+- Add zlib_dll_FAQ.txt to contrib [Truta]
+- Add UL to some constants [Truta]
+- Update minizip and vstudio [Vollant]
+- Remove vestigial NEED_DUMMY_RETURN from zconf.in.h
+- Expand use of NO_DUMMY_DECL to avoid all dummy structures
+- Added iostream3 to contrib [Schwardt]
+- Replace rewind() with fseek() for WinCE [Truta]
+- Improve setting of zlib format compression level flags
+    - Report 0 for huffman and rle strategies and for level == 0 or 1
+    - Report 2 only for level == 6
+- Only deal with 64K limit when necessary at compile time [Truta]
+- Allow TOO_FAR check to be turned off at compile time [Truta]
+- Add gzclearerr() function [Souza]
+- Add gzungetc() function
+
+Changes in 1.2.0.1 (17 March 2003)
+- Add Z_RLE strategy for run-length encoding [Truta]
+    - When Z_RLE requested, restrict matches to distance one
+    - Update zlib.h, minigzip.c, gzopen(), gzdopen() for Z_RLE
+- Correct FASTEST compilation to allow level == 0
+- Clean up what gets compiled for FASTEST
+- Incorporate changes to zconf.in.h [Vollant]
+    - Refine detection of Turbo C need for dummy returns
+    - Refine ZLIB_DLL compilation
+    - Include additional header file on VMS for off_t typedef
+- Try to use _vsnprintf where it supplants vsprintf [Vollant]
+- Add some casts in inffast.c
+- Enchance comments in zlib.h on what happens if gzprintf() tries to
+  write more than 4095 bytes before compression
+- Remove unused state from inflateBackEnd()
+- Remove exit(0) from minigzip.c, example.c
+- Get rid of all those darn tabs
+- Add "check" target to Makefile.in that does the same thing as "test"
+- Add "mostlyclean" and "maintainer-clean" targets to Makefile.in
+- Update contrib/inflate86 [Anderson]
+- Update contrib/testzlib, contrib/vstudio, contrib/minizip [Vollant]
+- Add msdos and win32 directories with makefiles [Truta]
+- More additions and improvements to the FAQ
+
+Changes in 1.2.0 (9 March 2003)
+- New and improved inflate code
+    - About 20% faster
+    - Does not allocate 32K window unless and until needed
+    - Automatically detects and decompresses gzip streams
+    - Raw inflate no longer needs an extra dummy byte at end
+    - Added inflateBack functions using a callback interface--even faster
+      than inflate, useful for file utilities (gzip, zip)
+    - Added inflateCopy() function to record state for random access on
+      externally generated deflate streams (e.g. in gzip files)
+    - More readable code (I hope)
+- New and improved crc32()
+    - About 50% faster, thanks to suggestions from Rodney Brown
+- Add deflateBound() and compressBound() functions
+- Fix memory leak in deflateInit2()
+- Permit setting dictionary for raw deflate (for parallel deflate)
+- Fix const declaration for gzwrite()
+- Check for some malloc() failures in gzio.c
+- Fix bug in gzopen() on single-byte file 0x1f
+- Fix bug in gzread() on concatenated file with 0x1f at end of buffer
+  and next buffer doesn't start with 0x8b
+- Fix uncompress() to return Z_DATA_ERROR on truncated input
+- Free memory at end of example.c
+- Remove MAX #define in trees.c (conflicted with some libraries)
+- Fix static const's in deflate.c, gzio.c, and zutil.[ch]
+- Declare malloc() and free() in gzio.c if STDC not defined
+- Use malloc() instead of calloc() in zutil.c if int big enough
+- Define STDC for AIX
+- Add aix/ with approach for compiling shared library on AIX
+- Add HP-UX support for shared libraries in configure
+- Add OpenUNIX support for shared libraries in configure
+- Use $cc instead of gcc to build shared library
+- Make prefix directory if needed when installing
+- Correct Macintosh avoidance of typedef Byte in zconf.h
+- Correct Turbo C memory allocation when under Linux
+- Use libz.a instead of -lz in Makefile (assure use of compiled library)
+- Update configure to check for snprintf or vsnprintf functions and their
+  return value, warn during make if using an insecure function
+- Fix configure problem with compile-time knowledge of HAVE_UNISTD_H that
+  is lost when library is used--resolution is to build new zconf.h
+- Documentation improvements (in zlib.h):
+    - Document raw deflate and inflate
+    - Update RFCs URL
+    - Point out that zlib and gzip formats are different
+    - Note that Z_BUF_ERROR is not fatal
+    - Document string limit for gzprintf() and possible buffer overflow
+    - Note requirement on avail_out when flushing
+    - Note permitted values of flush parameter of inflate()
+- Add some FAQs (and even answers) to the FAQ
+- Add contrib/inflate86/ for x86 faster inflate
+- Add contrib/blast/ for PKWare Data Compression Library decompression
+- Add contrib/puff/ simple inflate for deflate format description
+
+Changes in 1.1.4 (11 March 2002)
+- ZFREE was repeated on same allocation on some error conditions.
+  This creates a security problem described in
+  http://www.zlib.org/advisory-2002-03-11.txt
+- Returned incorrect error (Z_MEM_ERROR) on some invalid data
+- Avoid accesses before window for invalid distances with inflate window
+  less than 32K.
+- force windowBits > 8 to avoid a bug in the encoder for a window size
+  of 256 bytes. (A complete fix will be available in 1.1.5).
+
+Changes in 1.1.3 (9 July 1998)
+- fix "an inflate input buffer bug that shows up on rare but persistent
+  occasions" (Mark)
+- fix gzread and gztell for concatenated .gz files (Didier Le Botlan)
+- fix gzseek(..., SEEK_SET) in write mode
+- fix crc check after a gzeek (Frank Faubert)
+- fix miniunzip when the last entry in a zip file is itself a zip file
+  (J Lillge)
+- add contrib/asm586 and contrib/asm686 (Brian Raiter)
+  See http://www.muppetlabs.com/~breadbox/software/assembly.html
+- add support for Delphi 3 in contrib/delphi (Bob Dellaca)
+- add support for C++Builder 3 and Delphi 3 in contrib/delphi2 (Davide Moretti)
+- do not exit prematurely in untgz if 0 at start of block (Magnus Holmgren)
+- use macro EXTERN instead of extern to support DLL for BeOS (Sander Stoks)
+- added a FAQ file
+
+- Support gzdopen on Mac with Metrowerks (Jason Linhart)
+- Do not redefine Byte on Mac (Brad Pettit & Jason Linhart)
+- define SEEK_END too if SEEK_SET is not defined (Albert Chin-A-Young)
+- avoid some warnings with Borland C (Tom Tanner)
+- fix a problem in contrib/minizip/zip.c for 16-bit MSDOS (Gilles Vollant)
+- emulate utime() for WIN32 in contrib/untgz  (Gilles Vollant)
+- allow several arguments to configure (Tim Mooney, Frodo Looijaard)
+- use libdir and includedir in Makefile.in (Tim Mooney)
+- support shared libraries on OSF1 V4 (Tim Mooney)
+- remove so_locations in "make clean"  (Tim Mooney)
+- fix maketree.c compilation error (Glenn, Mark)
+- Python interface to zlib now in Python 1.5 (Jeremy Hylton)
+- new Makefile.riscos (Rich Walker)
+- initialize static descriptors in trees.c for embedded targets (Nick Smith)
+- use "foo-gz" in example.c for RISCOS and VMS (Nick Smith)
+- add the OS/2 files in Makefile.in too (Andrew Zabolotny)
+- fix fdopen and halloc macros for Microsoft C 6.0 (Tom Lane)
+- fix maketree.c to allow clean compilation of inffixed.h (Mark)
+- fix parameter check in deflateCopy (Gunther Nikl)
+- cleanup trees.c, use compressed_len only in debug mode (Christian Spieler)
+- Many portability patches by Christian Spieler:
+  . zutil.c, zutil.h: added "const" for zmem*
+  . Make_vms.com: fixed some typos
+  . Make_vms.com: msdos/Makefile.*: removed zutil.h from some dependency lists
+  . msdos/Makefile.msc: remove "default rtl link library" info from obj files
+  . msdos/Makefile.*: use model-dependent name for the built zlib library
+  . msdos/Makefile.emx, nt/Makefile.emx, nt/Makefile.gcc:
+     new makefiles, for emx (DOS/OS2), emx&rsxnt and mingw32 (Windows 9x / NT)
+- use define instead of typedef for Bytef also for MSC small/medium (Tom Lane)
+- replace __far with _far for better portability (Christian Spieler, Tom Lane)
+- fix test for errno.h in configure (Tim Newsham)
+
+Changes in 1.1.2 (19 March 98)
+- added contrib/minzip, mini zip and unzip based on zlib (Gilles Vollant)
+  See http://www.winimage.com/zLibDll/unzip.html
+- preinitialize the inflate tables for fixed codes, to make the code
+  completely thread safe (Mark)
+- some simplifications and slight speed-up to the inflate code (Mark)
+- fix gzeof on non-compressed files (Allan Schrum)
+- add -std1 option in configure for OSF1 to fix gzprintf (Martin Mokrejs)
+- use default value of 4K for Z_BUFSIZE for 16-bit MSDOS (Tim Wegner + Glenn)
+- added os2/Makefile.def and os2/zlib.def (Andrew Zabolotny)
+- add shared lib support for UNIX_SV4.2MP (MATSUURA Takanori)
+- do not wrap extern "C" around system includes (Tom Lane)
+- mention zlib binding for TCL in README (Andreas Kupries)
+- added amiga/Makefile.pup for Amiga powerUP SAS/C PPC (Andreas Kleinert)
+- allow "make install prefix=..." even after configure (Glenn Randers-Pehrson)
+- allow "configure --prefix $HOME" (Tim Mooney)
+- remove warnings in example.c and gzio.c (Glenn Randers-Pehrson)
+- move Makefile.sas to amiga/Makefile.sas
+
+Changes in 1.1.1 (27 Feb 98)
+- fix macros _tr_tally_* in deflate.h for debug mode  (Glenn Randers-Pehrson)
+- remove block truncation heuristic which had very marginal effect for zlib
+  (smaller lit_bufsize than in gzip 1.2.4) and degraded a little the
+  compression ratio on some files. This also allows inlining _tr_tally for
+  matches in deflate_slow.
+- added msdos/Makefile.w32 for WIN32 Microsoft Visual C++ (Bob Frazier)
+
+Changes in 1.1.0 (24 Feb 98)
+- do not return STREAM_END prematurely in inflate (John Bowler)
+- revert to the zlib 1.0.8 inflate to avoid the gcc 2.8.0 bug (Jeremy Buhler)
+- compile with -DFASTEST to get compression code optimized for speed only
+- in minigzip, try mmap'ing the input file first (Miguel Albrecht)
+- increase size of I/O buffers in minigzip.c and gzio.c (not a big gain
+  on Sun but significant on HP)
+
+- add a pointer to experimental unzip library in README (Gilles Vollant)
+- initialize variable gcc in configure (Chris Herborth)
+
+Changes in 1.0.9 (17 Feb 1998)
+- added gzputs and gzgets functions
+- do not clear eof flag in gzseek (Mark Diekhans)
+- fix gzseek for files in transparent mode (Mark Diekhans)
+- do not assume that vsprintf returns the number of bytes written (Jens Krinke)
+- replace EXPORT with ZEXPORT to avoid conflict with other programs
+- added compress2 in zconf.h, zlib.def, zlib.dnt
+- new asm code from Gilles Vollant in contrib/asm386
+- simplify the inflate code (Mark):
+ . Replace ZALLOC's in huft_build() with single ZALLOC in inflate_blocks_new()
+ . ZALLOC the length list in inflate_trees_fixed() instead of using stack
+ . ZALLOC the value area for huft_build() instead of using stack
+ . Simplify Z_FINISH check in inflate()
+
+- Avoid gcc 2.8.0 comparison bug a little differently than zlib 1.0.8
+- in inftrees.c, avoid cc -O bug on HP (Farshid Elahi)
+- in zconf.h move the ZLIB_DLL stuff earlier to avoid problems with
+  the declaration of FAR (Gilles VOllant)
+- install libz.so* with mode 755 (executable) instead of 644 (Marc Lehmann)
+- read_buf buf parameter of type Bytef* instead of charf*
+- zmemcpy parameters are of type Bytef*, not charf* (Joseph Strout)
+- do not redeclare unlink in minigzip.c for WIN32 (John Bowler)
+- fix check for presence of directories in "make install" (Ian Willis)
+
+Changes in 1.0.8 (27 Jan 1998)
+- fixed offsets in contrib/asm386/gvmat32.asm (Gilles Vollant)
+- fix gzgetc and gzputc for big endian systems (Markus Oberhumer)
+- added compress2() to allow setting the compression level
+- include sys/types.h to get off_t on some systems (Marc Lehmann & QingLong)
+- use constant arrays for the static trees in trees.c instead of computing
+  them at run time (thanks to Ken Raeburn for this suggestion). To create
+  trees.h, compile with GEN_TREES_H and run "make test".
+- check return code of example in "make test" and display result
+- pass minigzip command line options to file_compress
+- simplifying code of inflateSync to avoid gcc 2.8 bug
+
+- support CC="gcc -Wall" in configure -s (QingLong)
+- avoid a flush caused by ftell in gzopen for write mode (Ken Raeburn)
+- fix test for shared library support to avoid compiler warnings
+- zlib.lib -> zlib.dll in msdos/zlib.rc (Gilles Vollant)
+- check for TARGET_OS_MAC in addition to MACOS (Brad Pettit)
+- do not use fdopen for Metrowerks on Mac (Brad Pettit))
+- add checks for gzputc and gzputc in example.c
+- avoid warnings in gzio.c and deflate.c (Andreas Kleinert)
+- use const for the CRC table (Ken Raeburn)
+- fixed "make uninstall" for shared libraries
+- use Tracev instead of Trace in infblock.c
+- in example.c use correct compressed length for test_sync
+- suppress +vnocompatwarnings in configure for HPUX (not always supported)
+
+Changes in 1.0.7 (20 Jan 1998)
+- fix gzseek which was broken in write mode
+- return error for gzseek to negative absolute position
+- fix configure for Linux (Chun-Chung Chen)
+- increase stack space for MSC (Tim Wegner)
+- get_crc_table and inflateSyncPoint are EXPORTed (Gilles Vollant)
+- define EXPORTVA for gzprintf (Gilles Vollant)
+- added man page zlib.3 (Rick Rodgers)
+- for contrib/untgz, fix makedir() and improve Makefile
+
+- check gzseek in write mode in example.c
+- allocate extra buffer for seeks only if gzseek is actually called
+- avoid signed/unsigned comparisons (Tim Wegner, Gilles Vollant)
+- add inflateSyncPoint in zconf.h
+- fix list of exported functions in nt/zlib.dnt and mdsos/zlib.def
+
+Changes in 1.0.6 (19 Jan 1998)
+- add functions gzprintf, gzputc, gzgetc, gztell, gzeof, gzseek, gzrewind and
+  gzsetparams (thanks to Roland Giersig and Kevin Ruland for some of this code)
+- Fix a deflate bug occurring only with compression level 0 (thanks to
+  Andy Buckler for finding this one).
+- In minigzip, pass transparently also the first byte for .Z files.
+- return Z_BUF_ERROR instead of Z_OK if output buffer full in uncompress()
+- check Z_FINISH in inflate (thanks to Marc Schluper)
+- Implement deflateCopy (thanks to Adam Costello)
+- make static libraries by default in configure, add --shared option.
+- move MSDOS or Windows specific files to directory msdos
+- suppress the notion of partial flush to simplify the interface
+  (but the symbol Z_PARTIAL_FLUSH is kept for compatibility with 1.0.4)
+- suppress history buffer provided by application to simplify the interface
+  (this feature was not implemented anyway in 1.0.4)
+- next_in and avail_in must be initialized before calling inflateInit or
+  inflateInit2
+- add EXPORT in all exported functions (for Windows DLL)
+- added Makefile.nt (thanks to Stephen Williams)
+- added the unsupported "contrib" directory:
+   contrib/asm386/ by Gilles Vollant <info@winimage.com>
+        386 asm code replacing longest_match().
+   contrib/iostream/ by Kevin Ruland <kevin@rodin.wustl.edu>
+        A C++ I/O streams interface to the zlib gz* functions
+   contrib/iostream2/  by Tyge Løvset <Tyge.Lovset@cmr.no>
+        Another C++ I/O streams interface
+   contrib/untgz/  by "Pedro A. Aranda Guti\irrez" <paag@tid.es>
+        A very simple tar.gz file extractor using zlib
+   contrib/visual-basic.txt by Carlos Rios <c_rios@sonda.cl>
+        How to use compress(), uncompress() and the gz* functions from VB.
+- pass params -f (filtered data), -h (huffman only), -1 to -9 (compression
+  level) in minigzip (thanks to Tom Lane)
+
+- use const for rommable constants in deflate
+- added test for gzseek and gztell in example.c
+- add undocumented function inflateSyncPoint() (hack for Paul Mackerras)
+- add undocumented function zError to convert error code to string
+  (for Tim Smithers)
+- Allow compilation of gzio with -DNO_DEFLATE to avoid the compression code.
+- Use default memcpy for Symantec MSDOS compiler.
+- Add EXPORT keyword for check_func (needed for Windows DLL)
+- add current directory to LD_LIBRARY_PATH for "make test"
+- create also a link for libz.so.1
+- added support for FUJITSU UXP/DS (thanks to Toshiaki Nomura)
+- use $(SHAREDLIB) instead of libz.so in Makefile.in (for HPUX)
+- added -soname for Linux in configure (Chun-Chung Chen,
+- assign numbers to the exported functions in zlib.def (for Windows DLL)
+- add advice in zlib.h for best usage of deflateSetDictionary
+- work around compiler bug on Atari (cast Z_NULL in call of s->checkfn)
+- allow compilation with ANSI keywords only enabled for TurboC in large model
+- avoid "versionString"[0] (Borland bug)
+- add NEED_DUMMY_RETURN for Borland
+- use variable z_verbose for tracing in debug mode (L. Peter Deutsch).
+- allow compilation with CC
+- defined STDC for OS/2 (David Charlap)
+- limit external names to 8 chars for MVS (Thomas Lund)
+- in minigzip.c, use static buffers only for 16-bit systems
+- fix suffix check for "minigzip -d foo.gz"
+- do not return an error for the 2nd of two consecutive gzflush() (Felix Lee)
+- use _fdopen instead of fdopen for MSC >= 6.0 (Thomas Fanslau)
+- added makelcc.bat for lcc-win32 (Tom St Denis)
+- in Makefile.dj2, use copy and del instead of install and rm (Frank Donahoe)
+- Avoid expanded $Id$. Use "rcs -kb" or "cvs admin -kb" to avoid Id expansion.
+- check for unistd.h in configure (for off_t)
+- remove useless check parameter in inflate_blocks_free
+- avoid useless assignment of s->check to itself in inflate_blocks_new
+- do not flush twice in gzclose (thanks to Ken Raeburn)
+- rename FOPEN as F_OPEN to avoid clash with /usr/include/sys/file.h
+- use NO_ERRNO_H instead of enumeration of operating systems with errno.h
+- work around buggy fclose on pipes for HP/UX
+- support zlib DLL with BORLAND C++ 5.0 (thanks to Glenn Randers-Pehrson)
+- fix configure if CC is already equal to gcc
+
+Changes in 1.0.5 (3 Jan 98)
+- Fix inflate to terminate gracefully when fed corrupted or invalid data
+- Use const for rommable constants in inflate
+- Eliminate memory leaks on error conditions in inflate
+- Removed some vestigial code in inflate
+- Update web address in README
+
+Changes in 1.0.4 (24 Jul 96)
+- In very rare conditions, deflate(s, Z_FINISH) could fail to produce an EOF
+  bit, so the decompressor could decompress all the correct data but went
+  on to attempt decompressing extra garbage data. This affected minigzip too.
+- zlibVersion and gzerror return const char* (needed for DLL)
+- port to RISCOS (no fdopen, no multiple dots, no unlink, no fileno)
+- use z_error only for DEBUG (avoid problem with DLLs)
+
+Changes in 1.0.3 (2 Jul 96)
+- use z_streamp instead of z_stream *, which is now a far pointer in MSDOS
+  small and medium models; this makes the library incompatible with previous
+  versions for these models. (No effect in large model or on other systems.)
+- return OK instead of BUF_ERROR if previous deflate call returned with
+  avail_out as zero but there is nothing to do
+- added memcmp for non STDC compilers
+- define NO_DUMMY_DECL for more Mac compilers (.h files merged incorrectly)
+- define __32BIT__ if __386__ or i386 is defined (pb. with Watcom and SCO)
+- better check for 16-bit mode MSC (avoids problem with Symantec)
+
+Changes in 1.0.2 (23 May 96)
+- added Windows DLL support
+- added a function zlibVersion (for the DLL support)
+- fixed declarations using Bytef in infutil.c (pb with MSDOS medium model)
+- Bytef is define's instead of typedef'd only for Borland C
+- avoid reading uninitialized memory in example.c
+- mention in README that the zlib format is now RFC1950
+- updated Makefile.dj2
+- added algorithm.doc
+
+Changes in 1.0.1 (20 May 96) [1.0 skipped to avoid confusion]
+- fix array overlay in deflate.c which sometimes caused bad compressed data
+- fix inflate bug with empty stored block
+- fix MSDOS medium model which was broken in 0.99
+- fix deflateParams() which could generate bad compressed data.
+- Bytef is define'd instead of typedef'ed (work around Borland bug)
+- added an INDEX file
+- new makefiles for DJGPP (Makefile.dj2), 32-bit Borland (Makefile.b32),
+  Watcom (Makefile.wat), Amiga SAS/C (Makefile.sas)
+- speed up adler32 for modern machines without auto-increment
+- added -ansi for IRIX in configure
+- static_init_done in trees.c is an int
+- define unlink as delete for VMS
+- fix configure for QNX
+- add configure branch for SCO and HPUX
+- avoid many warnings (unused variables, dead assignments, etc...)
+- no fdopen for BeOS
+- fix the Watcom fix for 32 bit mode (define FAR as empty)
+- removed redefinition of Byte for MKWERKS
+- work around an MWKERKS bug (incorrect merge of all .h files)
+
+Changes in 0.99 (27 Jan 96)
+- allow preset dictionary shared between compressor and decompressor
+- allow compression level 0 (no compression)
+- add deflateParams in zlib.h: allow dynamic change of compression level
+  and compression strategy.
+- test large buffers and deflateParams in example.c
+- add optional "configure" to build zlib as a shared library
+- suppress Makefile.qnx, use configure instead
+- fixed deflate for 64-bit systems (detected on Cray)
+- fixed inflate_blocks for 64-bit systems (detected on Alpha)
+- declare Z_DEFLATED in zlib.h (possible parameter for deflateInit2)
+- always return Z_BUF_ERROR when deflate() has nothing to do
+- deflateInit and inflateInit are now macros to allow version checking
+- prefix all global functions and types with z_ with -DZ_PREFIX
+- make falloc completely reentrant (inftrees.c)
+- fixed very unlikely race condition in ct_static_init
+- free in reverse order of allocation to help memory manager
+- use zlib-1.0/* instead of zlib/* inside the tar.gz
+- make zlib warning-free with "gcc -O3 -Wall -Wwrite-strings -Wpointer-arith
+  -Wconversion -Wstrict-prototypes -Wmissing-prototypes"
+- allow gzread on concatenated .gz files
+- deflateEnd now returns Z_DATA_ERROR if it was premature
+- deflate is finally (?) fully deterministic (no matches beyond end of input)
+- Document Z_SYNC_FLUSH
+- add uninstall in Makefile
+- Check for __cpluplus in zlib.h
+- Better test in ct_align for partial flush
+- avoid harmless warnings for Borland C++
+- initialize hash_head in deflate.c
+- avoid warning on fdopen (gzio.c) for HP cc -Aa
+- include stdlib.h for STDC compilers
+- include errno.h for Cray
+- ignore error if ranlib doesn't exist
+- call ranlib twice for NeXTSTEP
+- use exec_prefix instead of prefix for libz.a
+- renamed ct_* as _tr_* to avoid conflict with applications
+- clear z->msg in inflateInit2 before any error return
+- initialize opaque in example.c, gzio.c, deflate.c and inflate.c
+- fixed typo in zconf.h (_GNUC__ => __GNUC__)
+- check for WIN32 in zconf.h and zutil.c (avoid farmalloc in 32-bit mode)
+- fix typo in Make_vms.com (f$trnlnm -> f$getsyi)
+- in fcalloc, normalize pointer if size > 65520 bytes
+- don't use special fcalloc for 32 bit Borland C++
+- use STDC instead of __GO32__ to avoid redeclaring exit, calloc, etc...
+- use Z_BINARY instead of BINARY
+- document that gzclose after gzdopen will close the file
+- allow "a" as mode in gzopen.
+- fix error checking in gzread
+- allow skipping .gz extra-field on pipes
+- added reference to Perl interface in README
+- put the crc table in FAR data (I dislike more and more the medium model :)
+- added get_crc_table
+- added a dimension to all arrays (Borland C can't count).
+- workaround Borland C bug in declaration of inflate_codes_new & inflate_fast
+- guard against multiple inclusion of *.h (for precompiled header on Mac)
+- Watcom C pretends to be Microsoft C small model even in 32 bit mode.
+- don't use unsized arrays to avoid silly warnings by Visual C++:
+     warning C4746: 'inflate_mask' : unsized array treated as  '__far'
+     (what's wrong with far data in far model?).
+- define enum out of inflate_blocks_state to allow compilation with C++
+
+Changes in 0.95 (16 Aug 95)
+- fix MSDOS small and medium model (now easier to adapt to any compiler)
+- inlined send_bits
+- fix the final (:-) bug for deflate with flush (output was correct but
+  not completely flushed in rare occasions).
+- default window size is same for compression and decompression
+  (it's now sufficient to set MAX_WBITS in zconf.h).
+- voidp -> voidpf and voidnp -> voidp (for consistency with other
+  typedefs and because voidnp was not near in large model).
+
+Changes in 0.94 (13 Aug 95)
+- support MSDOS medium model
+- fix deflate with flush (could sometimes generate bad output)
+- fix deflateReset (zlib header was incorrectly suppressed)
+- added support for VMS
+- allow a compression level in gzopen()
+- gzflush now calls fflush
+- For deflate with flush, flush even if no more input is provided.
+- rename libgz.a as libz.a
+- avoid complex expression in infcodes.c triggering Turbo C bug
+- work around a problem with gcc on Alpha (in INSERT_STRING)
+- don't use inline functions (problem with some gcc versions)
+- allow renaming of Byte, uInt, etc... with #define.
+- avoid warning about (unused) pointer before start of array in deflate.c
+- avoid various warnings in gzio.c, example.c, infblock.c, adler32.c, zutil.c
+- avoid reserved word 'new' in trees.c
+
+Changes in 0.93 (25 June 95)
+- temporarily disable inline functions
+- make deflate deterministic
+- give enough lookahead for PARTIAL_FLUSH
+- Set binary mode for stdin/stdout in minigzip.c for OS/2
+- don't even use signed char in inflate (not portable enough)
+- fix inflate memory leak for segmented architectures
+
+Changes in 0.92 (3 May 95)
+- don't assume that char is signed (problem on SGI)
+- Clear bit buffer when starting a stored block
+- no memcpy on Pyramid
+- suppressed inftest.c
+- optimized fill_window, put longest_match inline for gcc
+- optimized inflate on stored blocks.
+- untabify all sources to simplify patches
+
+Changes in 0.91 (2 May 95)
+- Default MEM_LEVEL is 8 (not 9 for Unix) as documented in zlib.h
+- Document the memory requirements in zconf.h
+- added "make install"
+- fix sync search logic in inflateSync
+- deflate(Z_FULL_FLUSH) now works even if output buffer too short
+- after inflateSync, don't scare people with just "lo world"
+- added support for DJGPP
+
+Changes in 0.9 (1 May 95)
+- don't assume that zalloc clears the allocated memory (the TurboC bug
+  was Mark's bug after all :)
+- let again gzread copy uncompressed data unchanged (was working in 0.71)
+- deflate(Z_FULL_FLUSH), inflateReset and inflateSync are now fully implemented
+- added a test of inflateSync in example.c
+- moved MAX_WBITS to zconf.h because users might want to change that.
+- document explicitly that zalloc(64K) on MSDOS must return a normalized
+  pointer (zero offset)
+- added Makefiles for Microsoft C, Turbo C, Borland C++
+- faster crc32()
+
+Changes in 0.8 (29 April 95)
+- added fast inflate (inffast.c)
+- deflate(Z_FINISH) now returns Z_STREAM_END when done. Warning: this
+  is incompatible with previous versions of zlib which returned Z_OK.
+- work around a TurboC compiler bug (bad code for b << 0, see infutil.h)
+  (actually that was not a compiler bug, see 0.81 above)
+- gzread no longer reads one extra byte in certain cases
+- In gzio destroy(), don't reference a freed structure
+- avoid many warnings for MSDOS
+- avoid the ERROR symbol which is used by MS Windows
+
+Changes in 0.71 (14 April 95)
+- Fixed more MSDOS compilation problems :( There is still a bug with
+  TurboC large model.
+
+Changes in 0.7 (14 April 95)
+- Added full inflate support.
+- Simplified the crc32() interface. The pre- and post-conditioning
+  (one's complement) is now done inside crc32(). WARNING: this is
+  incompatible with previous versions; see zlib.h for the new usage.
+
+Changes in 0.61 (12 April 95)
+- workaround for a bug in TurboC. example and minigzip now work on MSDOS.
+
+Changes in 0.6 (11 April 95)
+- added minigzip.c
+- added gzdopen to reopen a file descriptor as gzFile
+- added transparent reading of non-gziped files in gzread.
+- fixed bug in gzread (don't read crc as data)
+- fixed bug in destroy (gzio.c) (don't return Z_STREAM_END for gzclose).
+- don't allocate big arrays in the stack (for MSDOS)
+- fix some MSDOS compilation problems
+
+Changes in 0.5:
+- do real compression in deflate.c. Z_PARTIAL_FLUSH is supported but
+  not yet Z_FULL_FLUSH.
+- support decompression but only in a single step (forced Z_FINISH)
+- added opaque object for zalloc and zfree.
+- added deflateReset and inflateReset
+- added a variable zlib_version for consistency checking.
+- renamed the 'filter' parameter of deflateInit2 as 'strategy'.
+  Added Z_FILTERED and Z_HUFFMAN_ONLY constants.
+
+Changes in 0.4:
+- avoid "zip" everywhere, use zlib instead of ziplib.
+- suppress Z_BLOCK_FLUSH, interpret Z_PARTIAL_FLUSH as block flush
+  if compression method == 8.
+- added adler32 and crc32
+- renamed deflateOptions as deflateInit2, call one or the other but not both
+- added the method parameter for deflateInit2.
+- added inflateInit2
+- simplied considerably deflateInit and inflateInit by not supporting
+  user-provided history buffer. This is supported only in deflateInit2
+  and inflateInit2.
+
+Changes in 0.3:
+- prefix all macro names with Z_
+- use Z_FINISH instead of deflateEnd to finish compression.
+- added Z_HUFFMAN_ONLY
+- added gzerror()
diff --git a/xs/src/png/zlib/FAQ b/xs/src/png/zlib/FAQ
new file mode 100644
index 000000000..99b7cf92e
--- /dev/null
+++ b/xs/src/png/zlib/FAQ
@@ -0,0 +1,368 @@
+
+                Frequently Asked Questions about zlib
+
+
+If your question is not there, please check the zlib home page
+http://zlib.net/ which may have more recent information.
+The lastest zlib FAQ is at http://zlib.net/zlib_faq.html
+
+
+ 1. Is zlib Y2K-compliant?
+
+    Yes. zlib doesn't handle dates.
+
+ 2. Where can I get a Windows DLL version?
+
+    The zlib sources can be compiled without change to produce a DLL.  See the
+    file win32/DLL_FAQ.txt in the zlib distribution.  Pointers to the
+    precompiled DLL are found in the zlib web site at http://zlib.net/ .
+
+ 3. Where can I get a Visual Basic interface to zlib?
+
+    See
+        * http://marknelson.us/1997/01/01/zlib-engine/
+        * win32/DLL_FAQ.txt in the zlib distribution
+
+ 4. compress() returns Z_BUF_ERROR.
+
+    Make sure that before the call of compress(), the length of the compressed
+    buffer is equal to the available size of the compressed buffer and not
+    zero.  For Visual Basic, check that this parameter is passed by reference
+    ("as any"), not by value ("as long").
+
+ 5. deflate() or inflate() returns Z_BUF_ERROR.
+
+    Before making the call, make sure that avail_in and avail_out are not zero.
+    When setting the parameter flush equal to Z_FINISH, also make sure that
+    avail_out is big enough to allow processing all pending input.  Note that a
+    Z_BUF_ERROR is not fatal--another call to deflate() or inflate() can be
+    made with more input or output space.  A Z_BUF_ERROR may in fact be
+    unavoidable depending on how the functions are used, since it is not
+    possible to tell whether or not there is more output pending when
+    strm.avail_out returns with zero.  See http://zlib.net/zlib_how.html for a
+    heavily annotated example.
+
+ 6. Where's the zlib documentation (man pages, etc.)?
+
+    It's in zlib.h .  Examples of zlib usage are in the files test/example.c
+    and test/minigzip.c, with more in examples/ .
+
+ 7. Why don't you use GNU autoconf or libtool or ...?
+
+    Because we would like to keep zlib as a very small and simple package.
+    zlib is rather portable and doesn't need much configuration.
+
+ 8. I found a bug in zlib.
+
+    Most of the time, such problems are due to an incorrect usage of zlib.
+    Please try to reproduce the problem with a small program and send the
+    corresponding source to us at zlib@gzip.org .  Do not send multi-megabyte
+    data files without prior agreement.
+
+ 9. Why do I get "undefined reference to gzputc"?
+
+    If "make test" produces something like
+
+       example.o(.text+0x154): undefined reference to `gzputc'
+
+    check that you don't have old files libz.* in /usr/lib, /usr/local/lib or
+    /usr/X11R6/lib. Remove any old versions, then do "make install".
+
+10. I need a Delphi interface to zlib.
+
+    See the contrib/delphi directory in the zlib distribution.
+
+11. Can zlib handle .zip archives?
+
+    Not by itself, no.  See the directory contrib/minizip in the zlib
+    distribution.
+
+12. Can zlib handle .Z files?
+
+    No, sorry.  You have to spawn an uncompress or gunzip subprocess, or adapt
+    the code of uncompress on your own.
+
+13. How can I make a Unix shared library?
+
+    By default a shared (and a static) library is built for Unix.  So:
+
+    make distclean
+    ./configure
+    make
+
+14. How do I install a shared zlib library on Unix?
+
+    After the above, then:
+
+    make install
+
+    However, many flavors of Unix come with a shared zlib already installed.
+    Before going to the trouble of compiling a shared version of zlib and
+    trying to install it, you may want to check if it's already there!  If you
+    can #include <zlib.h>, it's there.  The -lz option will probably link to
+    it.  You can check the version at the top of zlib.h or with the
+    ZLIB_VERSION symbol defined in zlib.h .
+
+15. I have a question about OttoPDF.
+
+    We are not the authors of OttoPDF. The real author is on the OttoPDF web
+    site: Joel Hainley, jhainley@myndkryme.com.
+
+16. Can zlib decode Flate data in an Adobe PDF file?
+
+    Yes. See http://www.pdflib.com/ . To modify PDF forms, see
+    http://sourceforge.net/projects/acroformtool/ .
+
+17. Why am I getting this "register_frame_info not found" error on Solaris?
+
+    After installing zlib 1.1.4 on Solaris 2.6, running applications using zlib
+    generates an error such as:
+
+        ld.so.1: rpm: fatal: relocation error: file /usr/local/lib/libz.so:
+        symbol __register_frame_info: referenced symbol not found
+
+    The symbol __register_frame_info is not part of zlib, it is generated by
+    the C compiler (cc or gcc).  You must recompile applications using zlib
+    which have this problem.  This problem is specific to Solaris.  See
+    http://www.sunfreeware.com for Solaris versions of zlib and applications
+    using zlib.
+
+18. Why does gzip give an error on a file I make with compress/deflate?
+
+    The compress and deflate functions produce data in the zlib format, which
+    is different and incompatible with the gzip format.  The gz* functions in
+    zlib on the other hand use the gzip format.  Both the zlib and gzip formats
+    use the same compressed data format internally, but have different headers
+    and trailers around the compressed data.
+
+19. Ok, so why are there two different formats?
+
+    The gzip format was designed to retain the directory information about a
+    single file, such as the name and last modification date.  The zlib format
+    on the other hand was designed for in-memory and communication channel
+    applications, and has a much more compact header and trailer and uses a
+    faster integrity check than gzip.
+
+20. Well that's nice, but how do I make a gzip file in memory?
+
+    You can request that deflate write the gzip format instead of the zlib
+    format using deflateInit2().  You can also request that inflate decode the
+    gzip format using inflateInit2().  Read zlib.h for more details.
+
+21. Is zlib thread-safe?
+
+    Yes.  However any library routines that zlib uses and any application-
+    provided memory allocation routines must also be thread-safe.  zlib's gz*
+    functions use stdio library routines, and most of zlib's functions use the
+    library memory allocation routines by default.  zlib's *Init* functions
+    allow for the application to provide custom memory allocation routines.
+
+    Of course, you should only operate on any given zlib or gzip stream from a
+    single thread at a time.
+
+22. Can I use zlib in my commercial application?
+
+    Yes.  Please read the license in zlib.h.
+
+23. Is zlib under the GNU license?
+
+    No.  Please read the license in zlib.h.
+
+24. The license says that altered source versions must be "plainly marked". So
+    what exactly do I need to do to meet that requirement?
+
+    You need to change the ZLIB_VERSION and ZLIB_VERNUM #defines in zlib.h.  In
+    particular, the final version number needs to be changed to "f", and an
+    identification string should be appended to ZLIB_VERSION.  Version numbers
+    x.x.x.f are reserved for modifications to zlib by others than the zlib
+    maintainers.  For example, if the version of the base zlib you are altering
+    is "1.2.3.4", then in zlib.h you should change ZLIB_VERNUM to 0x123f, and
+    ZLIB_VERSION to something like "1.2.3.f-zachary-mods-v3".  You can also
+    update the version strings in deflate.c and inftrees.c.
+
+    For altered source distributions, you should also note the origin and
+    nature of the changes in zlib.h, as well as in ChangeLog and README, along
+    with the dates of the alterations.  The origin should include at least your
+    name (or your company's name), and an email address to contact for help or
+    issues with the library.
+
+    Note that distributing a compiled zlib library along with zlib.h and
+    zconf.h is also a source distribution, and so you should change
+    ZLIB_VERSION and ZLIB_VERNUM and note the origin and nature of the changes
+    in zlib.h as you would for a full source distribution.
+
+25. Will zlib work on a big-endian or little-endian architecture, and can I
+    exchange compressed data between them?
+
+    Yes and yes.
+
+26. Will zlib work on a 64-bit machine?
+
+    Yes.  It has been tested on 64-bit machines, and has no dependence on any
+    data types being limited to 32-bits in length.  If you have any
+    difficulties, please provide a complete problem report to zlib@gzip.org
+
+27. Will zlib decompress data from the PKWare Data Compression Library?
+
+    No.  The PKWare DCL uses a completely different compressed data format than
+    does PKZIP and zlib.  However, you can look in zlib's contrib/blast
+    directory for a possible solution to your problem.
+
+28. Can I access data randomly in a compressed stream?
+
+    No, not without some preparation.  If when compressing you periodically use
+    Z_FULL_FLUSH, carefully write all the pending data at those points, and
+    keep an index of those locations, then you can start decompression at those
+    points.  You have to be careful to not use Z_FULL_FLUSH too often, since it
+    can significantly degrade compression.  Alternatively, you can scan a
+    deflate stream once to generate an index, and then use that index for
+    random access.  See examples/zran.c .
+
+29. Does zlib work on MVS, OS/390, CICS, etc.?
+
+    It has in the past, but we have not heard of any recent evidence.  There
+    were working ports of zlib 1.1.4 to MVS, but those links no longer work.
+    If you know of recent, successful applications of zlib on these operating
+    systems, please let us know.  Thanks.
+
+30. Is there some simpler, easier to read version of inflate I can look at to
+    understand the deflate format?
+
+    First off, you should read RFC 1951.  Second, yes.  Look in zlib's
+    contrib/puff directory.
+
+31. Does zlib infringe on any patents?
+
+    As far as we know, no.  In fact, that was originally the whole point behind
+    zlib.  Look here for some more information:
+
+    http://www.gzip.org/#faq11
+
+32. Can zlib work with greater than 4 GB of data?
+
+    Yes.  inflate() and deflate() will process any amount of data correctly.
+    Each call of inflate() or deflate() is limited to input and output chunks
+    of the maximum value that can be stored in the compiler's "unsigned int"
+    type, but there is no limit to the number of chunks.  Note however that the
+    strm.total_in and strm_total_out counters may be limited to 4 GB.  These
+    counters are provided as a convenience and are not used internally by
+    inflate() or deflate().  The application can easily set up its own counters
+    updated after each call of inflate() or deflate() to count beyond 4 GB.
+    compress() and uncompress() may be limited to 4 GB, since they operate in a
+    single call.  gzseek() and gztell() may be limited to 4 GB depending on how
+    zlib is compiled.  See the zlibCompileFlags() function in zlib.h.
+
+    The word "may" appears several times above since there is a 4 GB limit only
+    if the compiler's "long" type is 32 bits.  If the compiler's "long" type is
+    64 bits, then the limit is 16 exabytes.
+
+33. Does zlib have any security vulnerabilities?
+
+    The only one that we are aware of is potentially in gzprintf().  If zlib is
+    compiled to use sprintf() or vsprintf(), then there is no protection
+    against a buffer overflow of an 8K string space (or other value as set by
+    gzbuffer()), other than the caller of gzprintf() assuring that the output
+    will not exceed 8K.  On the other hand, if zlib is compiled to use
+    snprintf() or vsnprintf(), which should normally be the case, then there is
+    no vulnerability.  The ./configure script will display warnings if an
+    insecure variation of sprintf() will be used by gzprintf().  Also the
+    zlibCompileFlags() function will return information on what variant of
+    sprintf() is used by gzprintf().
+
+    If you don't have snprintf() or vsnprintf() and would like one, you can
+    find a portable implementation here:
+
+        http://www.ijs.si/software/snprintf/
+
+    Note that you should be using the most recent version of zlib.  Versions
+    1.1.3 and before were subject to a double-free vulnerability, and versions
+    1.2.1 and 1.2.2 were subject to an access exception when decompressing
+    invalid compressed data.
+
+34. Is there a Java version of zlib?
+
+    Probably what you want is to use zlib in Java. zlib is already included
+    as part of the Java SDK in the java.util.zip package. If you really want
+    a version of zlib written in the Java language, look on the zlib home
+    page for links: http://zlib.net/ .
+
+35. I get this or that compiler or source-code scanner warning when I crank it
+    up to maximally-pedantic. Can't you guys write proper code?
+
+    Many years ago, we gave up attempting to avoid warnings on every compiler
+    in the universe.  It just got to be a waste of time, and some compilers
+    were downright silly as well as contradicted each other.  So now, we simply
+    make sure that the code always works.
+
+36. Valgrind (or some similar memory access checker) says that deflate is
+    performing a conditional jump that depends on an uninitialized value.
+    Isn't that a bug?
+
+    No.  That is intentional for performance reasons, and the output of deflate
+    is not affected.  This only started showing up recently since zlib 1.2.x
+    uses malloc() by default for allocations, whereas earlier versions used
+    calloc(), which zeros out the allocated memory.  Even though the code was
+    correct, versions 1.2.4 and later was changed to not stimulate these
+    checkers.
+
+37. Will zlib read the (insert any ancient or arcane format here) compressed
+    data format?
+
+    Probably not. Look in the comp.compression FAQ for pointers to various
+    formats and associated software.
+
+38. How can I encrypt/decrypt zip files with zlib?
+
+    zlib doesn't support encryption.  The original PKZIP encryption is very
+    weak and can be broken with freely available programs.  To get strong
+    encryption, use GnuPG, http://www.gnupg.org/ , which already includes zlib
+    compression.  For PKZIP compatible "encryption", look at
+    http://www.info-zip.org/
+
+39. What's the difference between the "gzip" and "deflate" HTTP 1.1 encodings?
+
+    "gzip" is the gzip format, and "deflate" is the zlib format.  They should
+    probably have called the second one "zlib" instead to avoid confusion with
+    the raw deflate compressed data format.  While the HTTP 1.1 RFC 2616
+    correctly points to the zlib specification in RFC 1950 for the "deflate"
+    transfer encoding, there have been reports of servers and browsers that
+    incorrectly produce or expect raw deflate data per the deflate
+    specification in RFC 1951, most notably Microsoft.  So even though the
+    "deflate" transfer encoding using the zlib format would be the more
+    efficient approach (and in fact exactly what the zlib format was designed
+    for), using the "gzip" transfer encoding is probably more reliable due to
+    an unfortunate choice of name on the part of the HTTP 1.1 authors.
+
+    Bottom line: use the gzip format for HTTP 1.1 encoding.
+
+40. Does zlib support the new "Deflate64" format introduced by PKWare?
+
+    No.  PKWare has apparently decided to keep that format proprietary, since
+    they have not documented it as they have previous compression formats.  In
+    any case, the compression improvements are so modest compared to other more
+    modern approaches, that it's not worth the effort to implement.
+
+41. I'm having a problem with the zip functions in zlib, can you help?
+
+    There are no zip functions in zlib.  You are probably using minizip by
+    Giles Vollant, which is found in the contrib directory of zlib.  It is not
+    part of zlib.  In fact none of the stuff in contrib is part of zlib.  The
+    files in there are not supported by the zlib authors.  You need to contact
+    the authors of the respective contribution for help.
+
+42. The match.asm code in contrib is under the GNU General Public License.
+    Since it's part of zlib, doesn't that mean that all of zlib falls under the
+    GNU GPL?
+
+    No.  The files in contrib are not part of zlib.  They were contributed by
+    other authors and are provided as a convenience to the user within the zlib
+    distribution.  Each item in contrib has its own license.
+
+43. Is zlib subject to export controls?  What is its ECCN?
+
+    zlib is not subject to export controls, and so is classified as EAR99.
+
+44. Can you please sign these lengthy legal documents and fax them back to us
+    so that we can use your software in our product?
+
+    No. Go away. Shoo.
diff --git a/xs/src/png/zlib/INDEX b/xs/src/png/zlib/INDEX
new file mode 100644
index 000000000..2ba064120
--- /dev/null
+++ b/xs/src/png/zlib/INDEX
@@ -0,0 +1,68 @@
+CMakeLists.txt  cmake build file
+ChangeLog       history of changes
+FAQ             Frequently Asked Questions about zlib
+INDEX           this file
+Makefile        dummy Makefile that tells you to ./configure
+Makefile.in     template for Unix Makefile
+README          guess what
+configure       configure script for Unix
+make_vms.com    makefile for VMS
+test/example.c  zlib usages examples for build testing
+test/minigzip.c minimal gzip-like functionality for build testing
+test/infcover.c inf*.c code coverage for build coverage testing
+treebuild.xml   XML description of source file dependencies
+zconf.h.cmakein zconf.h template for cmake
+zconf.h.in      zconf.h template for configure
+zlib.3          Man page for zlib
+zlib.3.pdf      Man page in PDF format
+zlib.map        Linux symbol information
+zlib.pc.in      Template for pkg-config descriptor
+zlib.pc.cmakein zlib.pc template for cmake
+zlib2ansi       perl script to convert source files for C++ compilation
+
+amiga/          makefiles for Amiga SAS C
+as400/          makefiles for AS/400
+doc/            documentation for formats and algorithms
+msdos/          makefiles for MSDOS
+nintendods/     makefile for Nintendo DS
+old/            makefiles for various architectures and zlib documentation
+                files that have not yet been updated for zlib 1.2.x
+qnx/            makefiles for QNX
+watcom/         makefiles for OpenWatcom
+win32/          makefiles for Windows
+
+                zlib public header files (required for library use):
+zconf.h
+zlib.h
+
+                private source files used to build the zlib library:
+adler32.c
+compress.c
+crc32.c
+crc32.h
+deflate.c
+deflate.h
+gzclose.c
+gzguts.h
+gzlib.c
+gzread.c
+gzwrite.c
+infback.c
+inffast.c
+inffast.h
+inffixed.h
+inflate.c
+inflate.h
+inftrees.c
+inftrees.h
+trees.c
+trees.h
+uncompr.c
+zutil.c
+zutil.h
+
+                source files for sample programs
+See examples/README.examples
+
+                unsupported contributions by third parties
+See contrib/README.contrib
diff --git a/xs/src/png/zlib/Makefile b/xs/src/png/zlib/Makefile
new file mode 100644
index 000000000..6bba86c73
--- /dev/null
+++ b/xs/src/png/zlib/Makefile
@@ -0,0 +1,5 @@
+all:
+	-@echo "Please use ./configure first.  Thank you."
+
+distclean:
+	make -f Makefile.in distclean
diff --git a/xs/src/png/zlib/Makefile.in b/xs/src/png/zlib/Makefile.in
new file mode 100644
index 000000000..5a77949ff
--- /dev/null
+++ b/xs/src/png/zlib/Makefile.in
@@ -0,0 +1,410 @@
+# Makefile for zlib
+# Copyright (C) 1995-2017 Jean-loup Gailly, Mark Adler
+# For conditions of distribution and use, see copyright notice in zlib.h
+
+# To compile and test, type:
+#    ./configure; make test
+# Normally configure builds both a static and a shared library.
+# If you want to build just a static library, use: ./configure --static
+
+# To use the asm code, type:
+#    cp contrib/asm?86/match.S ./match.S
+#    make LOC=-DASMV OBJA=match.o
+
+# To install /usr/local/lib/libz.* and /usr/local/include/zlib.h, type:
+#    make install
+# To install in $HOME instead of /usr/local, use:
+#    make install prefix=$HOME
+
+CC=cc
+
+CFLAGS=-O
+#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
+#CFLAGS=-g -DZLIB_DEBUG
+#CFLAGS=-O3 -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
+#           -Wstrict-prototypes -Wmissing-prototypes
+
+SFLAGS=-O
+LDFLAGS=
+TEST_LDFLAGS=-L. libz.a
+LDSHARED=$(CC)
+CPP=$(CC) -E
+
+STATICLIB=libz.a
+SHAREDLIB=libz.so
+SHAREDLIBV=libz.so.1.2.11
+SHAREDLIBM=libz.so.1
+LIBS=$(STATICLIB) $(SHAREDLIBV)
+
+AR=ar
+ARFLAGS=rc
+RANLIB=ranlib
+LDCONFIG=ldconfig
+LDSHAREDLIBC=-lc
+TAR=tar
+SHELL=/bin/sh
+EXE=
+
+prefix = /usr/local
+exec_prefix = ${prefix}
+libdir = ${exec_prefix}/lib
+sharedlibdir = ${libdir}
+includedir = ${prefix}/include
+mandir = ${prefix}/share/man
+man3dir = ${mandir}/man3
+pkgconfigdir = ${libdir}/pkgconfig
+SRCDIR=
+ZINC=
+ZINCOUT=-I.
+
+OBJZ = adler32.o crc32.o deflate.o infback.o inffast.o inflate.o inftrees.o trees.o zutil.o
+OBJG = compress.o uncompr.o gzclose.o gzlib.o gzread.o gzwrite.o
+OBJC = $(OBJZ) $(OBJG)
+
+PIC_OBJZ = adler32.lo crc32.lo deflate.lo infback.lo inffast.lo inflate.lo inftrees.lo trees.lo zutil.lo
+PIC_OBJG = compress.lo uncompr.lo gzclose.lo gzlib.lo gzread.lo gzwrite.lo
+PIC_OBJC = $(PIC_OBJZ) $(PIC_OBJG)
+
+# to use the asm code: make OBJA=match.o, PIC_OBJA=match.lo
+OBJA =
+PIC_OBJA =
+
+OBJS = $(OBJC) $(OBJA)
+
+PIC_OBJS = $(PIC_OBJC) $(PIC_OBJA)
+
+all: static shared
+
+static: example$(EXE) minigzip$(EXE)
+
+shared: examplesh$(EXE) minigzipsh$(EXE)
+
+all64: example64$(EXE) minigzip64$(EXE)
+
+check: test
+
+test: all teststatic testshared
+
+teststatic: static
+	@TMPST=tmpst_$$; \
+	if echo hello world | ./minigzip | ./minigzip -d && ./example $$TMPST ; then \
+	  echo '		*** zlib test OK ***'; \
+	else \
+	  echo '		*** zlib test FAILED ***'; false; \
+	fi; \
+	rm -f $$TMPST
+
+testshared: shared
+	@LD_LIBRARY_PATH=`pwd`:$(LD_LIBRARY_PATH) ; export LD_LIBRARY_PATH; \
+	LD_LIBRARYN32_PATH=`pwd`:$(LD_LIBRARYN32_PATH) ; export LD_LIBRARYN32_PATH; \
+	DYLD_LIBRARY_PATH=`pwd`:$(DYLD_LIBRARY_PATH) ; export DYLD_LIBRARY_PATH; \
+	SHLIB_PATH=`pwd`:$(SHLIB_PATH) ; export SHLIB_PATH; \
+	TMPSH=tmpsh_$$; \
+	if echo hello world | ./minigzipsh | ./minigzipsh -d && ./examplesh $$TMPSH; then \
+	  echo '		*** zlib shared test OK ***'; \
+	else \
+	  echo '		*** zlib shared test FAILED ***'; false; \
+	fi; \
+	rm -f $$TMPSH
+
+test64: all64
+	@TMP64=tmp64_$$; \
+	if echo hello world | ./minigzip64 | ./minigzip64 -d && ./example64 $$TMP64; then \
+	  echo '		*** zlib 64-bit test OK ***'; \
+	else \
+	  echo '		*** zlib 64-bit test FAILED ***'; false; \
+	fi; \
+	rm -f $$TMP64
+
+infcover.o: $(SRCDIR)test/infcover.c $(SRCDIR)zlib.h zconf.h
+	$(CC) $(CFLAGS) $(ZINCOUT) -c -o $@ $(SRCDIR)test/infcover.c
+
+infcover: infcover.o libz.a
+	$(CC) $(CFLAGS) -o $@ infcover.o libz.a
+
+cover: infcover
+	rm -f *.gcda
+	./infcover
+	gcov inf*.c
+
+libz.a: $(OBJS)
+	$(AR) $(ARFLAGS) $@ $(OBJS)
+	-@ ($(RANLIB) $@ || true) >/dev/null 2>&1
+
+match.o: match.S
+	$(CPP) match.S > _match.s
+	$(CC) -c _match.s
+	mv _match.o match.o
+	rm -f _match.s
+
+match.lo: match.S
+	$(CPP) match.S > _match.s
+	$(CC) -c -fPIC _match.s
+	mv _match.o match.lo
+	rm -f _match.s
+
+example.o: $(SRCDIR)test/example.c $(SRCDIR)zlib.h zconf.h
+	$(CC) $(CFLAGS) $(ZINCOUT) -c -o $@ $(SRCDIR)test/example.c
+
+minigzip.o: $(SRCDIR)test/minigzip.c $(SRCDIR)zlib.h zconf.h
+	$(CC) $(CFLAGS) $(ZINCOUT) -c -o $@ $(SRCDIR)test/minigzip.c
+
+example64.o: $(SRCDIR)test/example.c $(SRCDIR)zlib.h zconf.h
+	$(CC) $(CFLAGS) $(ZINCOUT) -D_FILE_OFFSET_BITS=64 -c -o $@ $(SRCDIR)test/example.c
+
+minigzip64.o: $(SRCDIR)test/minigzip.c $(SRCDIR)zlib.h zconf.h
+	$(CC) $(CFLAGS) $(ZINCOUT) -D_FILE_OFFSET_BITS=64 -c -o $@ $(SRCDIR)test/minigzip.c
+
+
+adler32.o: $(SRCDIR)adler32.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)adler32.c
+
+crc32.o: $(SRCDIR)crc32.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)crc32.c
+
+deflate.o: $(SRCDIR)deflate.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)deflate.c
+
+infback.o: $(SRCDIR)infback.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)infback.c
+
+inffast.o: $(SRCDIR)inffast.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)inffast.c
+
+inflate.o: $(SRCDIR)inflate.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)inflate.c
+
+inftrees.o: $(SRCDIR)inftrees.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)inftrees.c
+
+trees.o: $(SRCDIR)trees.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)trees.c
+
+zutil.o: $(SRCDIR)zutil.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)zutil.c
+
+compress.o: $(SRCDIR)compress.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)compress.c
+
+uncompr.o: $(SRCDIR)uncompr.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)uncompr.c
+
+gzclose.o: $(SRCDIR)gzclose.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)gzclose.c
+
+gzlib.o: $(SRCDIR)gzlib.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)gzlib.c
+
+gzread.o: $(SRCDIR)gzread.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)gzread.c
+
+gzwrite.o: $(SRCDIR)gzwrite.c
+	$(CC) $(CFLAGS) $(ZINC) -c -o $@ $(SRCDIR)gzwrite.c
+
+
+adler32.lo: $(SRCDIR)adler32.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/adler32.o $(SRCDIR)adler32.c
+	-@mv objs/adler32.o $@
+
+crc32.lo: $(SRCDIR)crc32.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/crc32.o $(SRCDIR)crc32.c
+	-@mv objs/crc32.o $@
+
+deflate.lo: $(SRCDIR)deflate.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/deflate.o $(SRCDIR)deflate.c
+	-@mv objs/deflate.o $@
+
+infback.lo: $(SRCDIR)infback.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/infback.o $(SRCDIR)infback.c
+	-@mv objs/infback.o $@
+
+inffast.lo: $(SRCDIR)inffast.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/inffast.o $(SRCDIR)inffast.c
+	-@mv objs/inffast.o $@
+
+inflate.lo: $(SRCDIR)inflate.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/inflate.o $(SRCDIR)inflate.c
+	-@mv objs/inflate.o $@
+
+inftrees.lo: $(SRCDIR)inftrees.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/inftrees.o $(SRCDIR)inftrees.c
+	-@mv objs/inftrees.o $@
+
+trees.lo: $(SRCDIR)trees.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/trees.o $(SRCDIR)trees.c
+	-@mv objs/trees.o $@
+
+zutil.lo: $(SRCDIR)zutil.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/zutil.o $(SRCDIR)zutil.c
+	-@mv objs/zutil.o $@
+
+compress.lo: $(SRCDIR)compress.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/compress.o $(SRCDIR)compress.c
+	-@mv objs/compress.o $@
+
+uncompr.lo: $(SRCDIR)uncompr.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/uncompr.o $(SRCDIR)uncompr.c
+	-@mv objs/uncompr.o $@
+
+gzclose.lo: $(SRCDIR)gzclose.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/gzclose.o $(SRCDIR)gzclose.c
+	-@mv objs/gzclose.o $@
+
+gzlib.lo: $(SRCDIR)gzlib.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/gzlib.o $(SRCDIR)gzlib.c
+	-@mv objs/gzlib.o $@
+
+gzread.lo: $(SRCDIR)gzread.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/gzread.o $(SRCDIR)gzread.c
+	-@mv objs/gzread.o $@
+
+gzwrite.lo: $(SRCDIR)gzwrite.c
+	-@mkdir objs 2>/dev/null || test -d objs
+	$(CC) $(SFLAGS) $(ZINC) -DPIC -c -o objs/gzwrite.o $(SRCDIR)gzwrite.c
+	-@mv objs/gzwrite.o $@
+
+
+placebo $(SHAREDLIBV): $(PIC_OBJS) libz.a
+	$(LDSHARED) $(SFLAGS) -o $@ $(PIC_OBJS) $(LDSHAREDLIBC) $(LDFLAGS)
+	rm -f $(SHAREDLIB) $(SHAREDLIBM)
+	ln -s $@ $(SHAREDLIB)
+	ln -s $@ $(SHAREDLIBM)
+	-@rmdir objs
+
+example$(EXE): example.o $(STATICLIB)
+	$(CC) $(CFLAGS) -o $@ example.o $(TEST_LDFLAGS)
+
+minigzip$(EXE): minigzip.o $(STATICLIB)
+	$(CC) $(CFLAGS) -o $@ minigzip.o $(TEST_LDFLAGS)
+
+examplesh$(EXE): example.o $(SHAREDLIBV)
+	$(CC) $(CFLAGS) -o $@ example.o -L. $(SHAREDLIBV)
+
+minigzipsh$(EXE): minigzip.o $(SHAREDLIBV)
+	$(CC) $(CFLAGS) -o $@ minigzip.o -L. $(SHAREDLIBV)
+
+example64$(EXE): example64.o $(STATICLIB)
+	$(CC) $(CFLAGS) -o $@ example64.o $(TEST_LDFLAGS)
+
+minigzip64$(EXE): minigzip64.o $(STATICLIB)
+	$(CC) $(CFLAGS) -o $@ minigzip64.o $(TEST_LDFLAGS)
+
+install-libs: $(LIBS)
+	-@if [ ! -d $(DESTDIR)$(exec_prefix)  ]; then mkdir -p $(DESTDIR)$(exec_prefix); fi
+	-@if [ ! -d $(DESTDIR)$(libdir)       ]; then mkdir -p $(DESTDIR)$(libdir); fi
+	-@if [ ! -d $(DESTDIR)$(sharedlibdir) ]; then mkdir -p $(DESTDIR)$(sharedlibdir); fi
+	-@if [ ! -d $(DESTDIR)$(man3dir)      ]; then mkdir -p $(DESTDIR)$(man3dir); fi
+	-@if [ ! -d $(DESTDIR)$(pkgconfigdir) ]; then mkdir -p $(DESTDIR)$(pkgconfigdir); fi
+	rm -f $(DESTDIR)$(libdir)/$(STATICLIB)
+	cp $(STATICLIB) $(DESTDIR)$(libdir)
+	chmod 644 $(DESTDIR)$(libdir)/$(STATICLIB)
+	-@($(RANLIB) $(DESTDIR)$(libdir)/libz.a || true) >/dev/null 2>&1
+	-@if test -n "$(SHAREDLIBV)"; then \
+	  rm -f $(DESTDIR)$(sharedlibdir)/$(SHAREDLIBV); \
+	  cp $(SHAREDLIBV) $(DESTDIR)$(sharedlibdir); \
+	  echo "cp $(SHAREDLIBV) $(DESTDIR)$(sharedlibdir)"; \
+	  chmod 755 $(DESTDIR)$(sharedlibdir)/$(SHAREDLIBV); \
+	  echo "chmod 755 $(DESTDIR)$(sharedlibdir)/$(SHAREDLIBV)"; \
+	  rm -f $(DESTDIR)$(sharedlibdir)/$(SHAREDLIB) $(DESTDIR)$(sharedlibdir)/$(SHAREDLIBM); \
+	  ln -s $(SHAREDLIBV) $(DESTDIR)$(sharedlibdir)/$(SHAREDLIB); \
+	  ln -s $(SHAREDLIBV) $(DESTDIR)$(sharedlibdir)/$(SHAREDLIBM); \
+	  ($(LDCONFIG) || true)  >/dev/null 2>&1; \
+	fi
+	rm -f $(DESTDIR)$(man3dir)/zlib.3
+	cp $(SRCDIR)zlib.3 $(DESTDIR)$(man3dir)
+	chmod 644 $(DESTDIR)$(man3dir)/zlib.3
+	rm -f $(DESTDIR)$(pkgconfigdir)/zlib.pc
+	cp zlib.pc $(DESTDIR)$(pkgconfigdir)
+	chmod 644 $(DESTDIR)$(pkgconfigdir)/zlib.pc
+# The ranlib in install is needed on NeXTSTEP which checks file times
+# ldconfig is for Linux
+
+install: install-libs
+	-@if [ ! -d $(DESTDIR)$(includedir)   ]; then mkdir -p $(DESTDIR)$(includedir); fi
+	rm -f $(DESTDIR)$(includedir)/zlib.h $(DESTDIR)$(includedir)/zconf.h
+	cp $(SRCDIR)zlib.h zconf.h $(DESTDIR)$(includedir)
+	chmod 644 $(DESTDIR)$(includedir)/zlib.h $(DESTDIR)$(includedir)/zconf.h
+
+uninstall:
+	cd $(DESTDIR)$(includedir) && rm -f zlib.h zconf.h
+	cd $(DESTDIR)$(libdir) && rm -f libz.a; \
+	if test -n "$(SHAREDLIBV)" -a -f $(SHAREDLIBV); then \
+	  rm -f $(SHAREDLIBV) $(SHAREDLIB) $(SHAREDLIBM); \
+	fi
+	cd $(DESTDIR)$(man3dir) && rm -f zlib.3
+	cd $(DESTDIR)$(pkgconfigdir) && rm -f zlib.pc
+
+docs: zlib.3.pdf
+
+zlib.3.pdf: $(SRCDIR)zlib.3
+	groff -mandoc -f H -T ps $(SRCDIR)zlib.3 | ps2pdf - $@
+
+zconf.h.cmakein: $(SRCDIR)zconf.h.in
+	-@ TEMPFILE=zconfh_$$; \
+	echo "/#define ZCONF_H/ a\\\\\n#cmakedefine Z_PREFIX\\\\\n#cmakedefine Z_HAVE_UNISTD_H\n" >> $$TEMPFILE &&\
+	sed -f $$TEMPFILE $(SRCDIR)zconf.h.in > $@ &&\
+	touch -r $(SRCDIR)zconf.h.in $@ &&\
+	rm $$TEMPFILE
+
+zconf: $(SRCDIR)zconf.h.in
+	cp -p $(SRCDIR)zconf.h.in zconf.h
+
+mostlyclean: clean
+clean:
+	rm -f *.o *.lo *~ \
+	   example$(EXE) minigzip$(EXE) examplesh$(EXE) minigzipsh$(EXE) \
+	   example64$(EXE) minigzip64$(EXE) \
+	   infcover \
+	   libz.* foo.gz so_locations \
+	   _match.s maketree contrib/infback9/*.o
+	rm -rf objs
+	rm -f *.gcda *.gcno *.gcov
+	rm -f contrib/infback9/*.gcda contrib/infback9/*.gcno contrib/infback9/*.gcov
+
+maintainer-clean: distclean
+distclean: clean zconf zconf.h.cmakein docs
+	rm -f Makefile zlib.pc configure.log
+	-@rm -f .DS_Store
+	@if [ -f Makefile.in ]; then \
+	printf 'all:\n\t-@echo "Please use ./configure first.  Thank you."\n' > Makefile ; \
+	printf '\ndistclean:\n\tmake -f Makefile.in distclean\n' >> Makefile ; \
+	touch -r $(SRCDIR)Makefile.in Makefile ; fi
+	@if [ ! -f zconf.h.in ]; then rm -f zconf.h zconf.h.cmakein ; fi
+	@if [ ! -f zlib.3 ]; then rm -f zlib.3.pdf ; fi
+
+tags:
+	etags $(SRCDIR)*.[ch]
+
+adler32.o zutil.o: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h
+gzclose.o gzlib.o gzread.o gzwrite.o: $(SRCDIR)zlib.h zconf.h $(SRCDIR)gzguts.h
+compress.o example.o minigzip.o uncompr.o: $(SRCDIR)zlib.h zconf.h
+crc32.o: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)crc32.h
+deflate.o: $(SRCDIR)deflate.h $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h
+infback.o inflate.o: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)inftrees.h $(SRCDIR)inflate.h $(SRCDIR)inffast.h $(SRCDIR)inffixed.h
+inffast.o: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)inftrees.h $(SRCDIR)inflate.h $(SRCDIR)inffast.h
+inftrees.o: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)inftrees.h
+trees.o: $(SRCDIR)deflate.h $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)trees.h
+
+adler32.lo zutil.lo: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h
+gzclose.lo gzlib.lo gzread.lo gzwrite.lo: $(SRCDIR)zlib.h zconf.h $(SRCDIR)gzguts.h
+compress.lo example.lo minigzip.lo uncompr.lo: $(SRCDIR)zlib.h zconf.h
+crc32.lo: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)crc32.h
+deflate.lo: $(SRCDIR)deflate.h $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h
+infback.lo inflate.lo: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)inftrees.h $(SRCDIR)inflate.h $(SRCDIR)inffast.h $(SRCDIR)inffixed.h
+inffast.lo: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)inftrees.h $(SRCDIR)inflate.h $(SRCDIR)inffast.h
+inftrees.lo: $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)inftrees.h
+trees.lo: $(SRCDIR)deflate.h $(SRCDIR)zutil.h $(SRCDIR)zlib.h zconf.h $(SRCDIR)trees.h
diff --git a/xs/src/png/zlib/README b/xs/src/png/zlib/README
new file mode 100644
index 000000000..51106de47
--- /dev/null
+++ b/xs/src/png/zlib/README
@@ -0,0 +1,115 @@
+ZLIB DATA COMPRESSION LIBRARY
+
+zlib 1.2.11 is a general purpose data compression library.  All the code is
+thread safe.  The data format used by the zlib library is described by RFCs
+(Request for Comments) 1950 to 1952 in the files
+http://tools.ietf.org/html/rfc1950 (zlib format), rfc1951 (deflate format) and
+rfc1952 (gzip format).
+
+All functions of the compression library are documented in the file zlib.h
+(volunteer to write man pages welcome, contact zlib@gzip.org).  A usage example
+of the library is given in the file test/example.c which also tests that
+the library is working correctly.  Another example is given in the file
+test/minigzip.c.  The compression library itself is composed of all source
+files in the root directory.
+
+To compile all files and run the test program, follow the instructions given at
+the top of Makefile.in.  In short "./configure; make test", and if that goes
+well, "make install" should work for most flavors of Unix.  For Windows, use
+one of the special makefiles in win32/ or contrib/vstudio/ .  For VMS, use
+make_vms.com.
+
+Questions about zlib should be sent to <zlib@gzip.org>, or to Gilles Vollant
+<info@winimage.com> for the Windows DLL version.  The zlib home page is
+http://zlib.net/ .  Before reporting a problem, please check this site to
+verify that you have the latest version of zlib; otherwise get the latest
+version and check whether the problem still exists or not.
+
+PLEASE read the zlib FAQ http://zlib.net/zlib_faq.html before asking for help.
+
+Mark Nelson <markn@ieee.org> wrote an article about zlib for the Jan.  1997
+issue of Dr.  Dobb's Journal; a copy of the article is available at
+http://marknelson.us/1997/01/01/zlib-engine/ .
+
+The changes made in version 1.2.11 are documented in the file ChangeLog.
+
+Unsupported third party contributions are provided in directory contrib/ .
+
+zlib is available in Java using the java.util.zip package, documented at
+http://java.sun.com/developer/technicalArticles/Programming/compression/ .
+
+A Perl interface to zlib written by Paul Marquess <pmqs@cpan.org> is available
+at CPAN (Comprehensive Perl Archive Network) sites, including
+http://search.cpan.org/~pmqs/IO-Compress-Zlib/ .
+
+A Python interface to zlib written by A.M. Kuchling <amk@amk.ca> is
+available in Python 1.5 and later versions, see
+http://docs.python.org/library/zlib.html .
+
+zlib is built into tcl: http://wiki.tcl.tk/4610 .
+
+An experimental package to read and write files in .zip format, written on top
+of zlib by Gilles Vollant <info@winimage.com>, is available in the
+contrib/minizip directory of zlib.
+
+
+Notes for some targets:
+
+- For Windows DLL versions, please see win32/DLL_FAQ.txt
+
+- For 64-bit Irix, deflate.c must be compiled without any optimization. With
+  -O, one libpng test fails. The test works in 32 bit mode (with the -n32
+  compiler flag). The compiler bug has been reported to SGI.
+
+- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
+  when compiled with cc.
+
+- On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is
+  necessary to get gzprintf working correctly. This is done by configure.
+
+- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with
+  other compilers. Use "make test" to check your compiler.
+
+- gzdopen is not supported on RISCOS or BEOS.
+
+- For PalmOs, see http://palmzlib.sourceforge.net/
+
+
+Acknowledgments:
+
+  The deflate format used by zlib was defined by Phil Katz.  The deflate and
+  zlib specifications were written by L.  Peter Deutsch.  Thanks to all the
+  people who reported problems and suggested various improvements in zlib; they
+  are too numerous to cite here.
+
+Copyright notice:
+
+ (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+If you use the zlib library in a product, we would appreciate *not* receiving
+lengthy legal documents to sign.  The sources are provided for free but without
+warranty of any kind.  The library has been entirely written by Jean-loup
+Gailly and Mark Adler; it does not include third-party code.
+
+If you redistribute modified sources, we would appreciate that you include in
+the file ChangeLog history information documenting your changes.  Please read
+the FAQ for more information on the distribution of modified source versions.
diff --git a/xs/src/png/zlib/adler32.c b/xs/src/png/zlib/adler32.c
new file mode 100644
index 000000000..d0be4380a
--- /dev/null
+++ b/xs/src/png/zlib/adler32.c
@@ -0,0 +1,186 @@
+/* adler32.c -- compute the Adler-32 checksum of a data stream
+ * Copyright (C) 1995-2011, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zutil.h"
+
+local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
+
+#define BASE 65521U     /* largest prime smaller than 65536 */
+#define NMAX 5552
+/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
+
+#define DO1(buf,i)  {adler += (buf)[i]; sum2 += adler;}
+#define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
+#define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
+#define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
+#define DO16(buf)   DO8(buf,0); DO8(buf,8);
+
+/* use NO_DIVIDE if your processor does not do division in hardware --
+   try it both ways to see which is faster */
+#ifdef NO_DIVIDE
+/* note that this assumes BASE is 65521, where 65536 % 65521 == 15
+   (thank you to John Reiser for pointing this out) */
+#  define CHOP(a) \
+    do { \
+        unsigned long tmp = a >> 16; \
+        a &= 0xffffUL; \
+        a += (tmp << 4) - tmp; \
+    } while (0)
+#  define MOD28(a) \
+    do { \
+        CHOP(a); \
+        if (a >= BASE) a -= BASE; \
+    } while (0)
+#  define MOD(a) \
+    do { \
+        CHOP(a); \
+        MOD28(a); \
+    } while (0)
+#  define MOD63(a) \
+    do { /* this assumes a is not negative */ \
+        z_off64_t tmp = a >> 32; \
+        a &= 0xffffffffL; \
+        a += (tmp << 8) - (tmp << 5) + tmp; \
+        tmp = a >> 16; \
+        a &= 0xffffL; \
+        a += (tmp << 4) - tmp; \
+        tmp = a >> 16; \
+        a &= 0xffffL; \
+        a += (tmp << 4) - tmp; \
+        if (a >= BASE) a -= BASE; \
+    } while (0)
+#else
+#  define MOD(a) a %= BASE
+#  define MOD28(a) a %= BASE
+#  define MOD63(a) a %= BASE
+#endif
+
+/* ========================================================================= */
+uLong ZEXPORT adler32_z(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    z_size_t len;
+{
+    unsigned long sum2;
+    unsigned n;
+
+    /* split Adler-32 into component sums */
+    sum2 = (adler >> 16) & 0xffff;
+    adler &= 0xffff;
+
+    /* in case user likes doing a byte at a time, keep it fast */
+    if (len == 1) {
+        adler += buf[0];
+        if (adler >= BASE)
+            adler -= BASE;
+        sum2 += adler;
+        if (sum2 >= BASE)
+            sum2 -= BASE;
+        return adler | (sum2 << 16);
+    }
+
+    /* initial Adler-32 value (deferred check for len == 1 speed) */
+    if (buf == Z_NULL)
+        return 1L;
+
+    /* in case short lengths are provided, keep it somewhat fast */
+    if (len < 16) {
+        while (len--) {
+            adler += *buf++;
+            sum2 += adler;
+        }
+        if (adler >= BASE)
+            adler -= BASE;
+        MOD28(sum2);            /* only added so many BASE's */
+        return adler | (sum2 << 16);
+    }
+
+    /* do length NMAX blocks -- requires just one modulo operation */
+    while (len >= NMAX) {
+        len -= NMAX;
+        n = NMAX / 16;          /* NMAX is divisible by 16 */
+        do {
+            DO16(buf);          /* 16 sums unrolled */
+            buf += 16;
+        } while (--n);
+        MOD(adler);
+        MOD(sum2);
+    }
+
+    /* do remaining bytes (less than NMAX, still just one modulo) */
+    if (len) {                  /* avoid modulos if none remaining */
+        while (len >= 16) {
+            len -= 16;
+            DO16(buf);
+            buf += 16;
+        }
+        while (len--) {
+            adler += *buf++;
+            sum2 += adler;
+        }
+        MOD(adler);
+        MOD(sum2);
+    }
+
+    /* return recombined sums */
+    return adler | (sum2 << 16);
+}
+
+/* ========================================================================= */
+uLong ZEXPORT adler32(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    uInt len;
+{
+    return adler32_z(adler, buf, len);
+}
+
+/* ========================================================================= */
+local uLong adler32_combine_(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off64_t len2;
+{
+    unsigned long sum1;
+    unsigned long sum2;
+    unsigned rem;
+
+    /* for negative len, return invalid adler32 as a clue for debugging */
+    if (len2 < 0)
+        return 0xffffffffUL;
+
+    /* the derivation of this formula is left as an exercise for the reader */
+    MOD63(len2);                /* assumes len2 >= 0 */
+    rem = (unsigned)len2;
+    sum1 = adler1 & 0xffff;
+    sum2 = rem * sum1;
+    MOD(sum2);
+    sum1 += (adler2 & 0xffff) + BASE - 1;
+    sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
+    if (sum1 >= BASE) sum1 -= BASE;
+    if (sum1 >= BASE) sum1 -= BASE;
+    if (sum2 >= ((unsigned long)BASE << 1)) sum2 -= ((unsigned long)BASE << 1);
+    if (sum2 >= BASE) sum2 -= BASE;
+    return sum1 | (sum2 << 16);
+}
+
+/* ========================================================================= */
+uLong ZEXPORT adler32_combine(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off_t len2;
+{
+    return adler32_combine_(adler1, adler2, len2);
+}
+
+uLong ZEXPORT adler32_combine64(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off64_t len2;
+{
+    return adler32_combine_(adler1, adler2, len2);
+}
diff --git a/xs/src/png/zlib/amiga/Makefile.pup b/xs/src/png/zlib/amiga/Makefile.pup
new file mode 100644
index 000000000..8940c120f
--- /dev/null
+++ b/xs/src/png/zlib/amiga/Makefile.pup
@@ -0,0 +1,69 @@
+# Amiga powerUP (TM) Makefile
+# makefile for libpng and SAS C V6.58/7.00 PPC compiler
+# Copyright (C) 1998 by Andreas R. Kleinert
+
+LIBNAME	= libzip.a
+
+CC	= scppc
+CFLAGS	= NOSTKCHK NOSINT OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL \
+	  OPTLOOP OPTRDEP=8 OPTDEP=8 OPTCOMP=8 NOVER
+AR	= ppc-amigaos-ar cr
+RANLIB	= ppc-amigaos-ranlib
+LD	= ppc-amigaos-ld -r
+LDFLAGS	= -o
+LDLIBS	= LIB:scppc.a LIB:end.o
+RM	= delete quiet
+
+OBJS = adler32.o compress.o crc32.o gzclose.o gzlib.o gzread.o gzwrite.o \
+       uncompr.o deflate.o trees.o zutil.o inflate.o infback.o inftrees.o inffast.o
+
+TEST_OBJS = example.o minigzip.o
+
+all: example minigzip
+
+check: test
+test: all
+	example
+	echo hello world | minigzip | minigzip -d
+
+$(LIBNAME): $(OBJS)
+	$(AR) $@ $(OBJS)
+	-$(RANLIB) $@
+
+example: example.o $(LIBNAME)
+	$(LD) $(LDFLAGS) $@ LIB:c_ppc.o $@.o $(LIBNAME) $(LDLIBS)
+
+minigzip: minigzip.o $(LIBNAME)
+	$(LD) $(LDFLAGS) $@ LIB:c_ppc.o $@.o $(LIBNAME) $(LDLIBS)
+
+mostlyclean: clean
+clean:
+	$(RM) *.o example minigzip $(LIBNAME) foo.gz
+
+zip:
+	zip -ul9 zlib README ChangeLog Makefile Make????.??? Makefile.?? \
+	  descrip.mms *.[ch]
+
+tgz:
+	cd ..; tar cfz zlib/zlib.tgz zlib/README zlib/ChangeLog zlib/Makefile \
+	  zlib/Make????.??? zlib/Makefile.?? zlib/descrip.mms zlib/*.[ch]
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+adler32.o: zlib.h zconf.h
+compress.o: zlib.h zconf.h
+crc32.o: crc32.h zlib.h zconf.h
+deflate.o: deflate.h zutil.h zlib.h zconf.h
+example.o: zlib.h zconf.h
+gzclose.o: zlib.h zconf.h gzguts.h
+gzlib.o: zlib.h zconf.h gzguts.h
+gzread.o: zlib.h zconf.h gzguts.h
+gzwrite.o: zlib.h zconf.h gzguts.h
+inffast.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+inflate.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+infback.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+inftrees.o: zutil.h zlib.h zconf.h inftrees.h
+minigzip.o: zlib.h zconf.h
+trees.o: deflate.h zutil.h zlib.h zconf.h trees.h
+uncompr.o: zlib.h zconf.h
+zutil.o: zutil.h zlib.h zconf.h
diff --git a/xs/src/png/zlib/amiga/Makefile.sas b/xs/src/png/zlib/amiga/Makefile.sas
new file mode 100644
index 000000000..749e29152
--- /dev/null
+++ b/xs/src/png/zlib/amiga/Makefile.sas
@@ -0,0 +1,68 @@
+# SMakefile for zlib
+# Modified from the standard UNIX Makefile Copyright Jean-loup Gailly
+# Osma Ahvenlampi <Osma.Ahvenlampi@hut.fi>
+# Amiga, SAS/C 6.56 & Smake
+
+CC=sc
+CFLAGS=OPT
+#CFLAGS=OPT CPU=68030
+#CFLAGS=DEBUG=LINE
+LDFLAGS=LIB z.lib
+
+SCOPTIONS=OPTSCHED OPTINLINE OPTALIAS OPTTIME OPTINLOCAL STRMERGE \
+       NOICONS PARMS=BOTH NOSTACKCHECK UTILLIB NOVERSION ERRORREXX \
+       DEF=POSTINC
+
+OBJS = adler32.o compress.o crc32.o gzclose.o gzlib.o gzread.o gzwrite.o \
+       uncompr.o deflate.o trees.o zutil.o inflate.o infback.o inftrees.o inffast.o
+
+TEST_OBJS = example.o minigzip.o
+
+all: SCOPTIONS example minigzip
+
+check: test
+test: all
+	example
+	echo hello world | minigzip | minigzip -d
+
+install: z.lib
+	copy clone zlib.h zconf.h INCLUDE:
+	copy clone z.lib LIB:
+
+z.lib: $(OBJS)
+	oml z.lib r $(OBJS)
+
+example: example.o z.lib
+	$(CC) $(CFLAGS) LINK TO $@ example.o $(LDFLAGS)
+
+minigzip: minigzip.o z.lib
+	$(CC) $(CFLAGS) LINK TO $@ minigzip.o $(LDFLAGS)
+
+mostlyclean: clean
+clean:
+	-delete force quiet example minigzip *.o z.lib foo.gz *.lnk SCOPTIONS
+
+SCOPTIONS: Makefile.sas
+	copy to $@ <from <
+$(SCOPTIONS)
+<
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+adler32.o: zlib.h zconf.h
+compress.o: zlib.h zconf.h
+crc32.o: crc32.h zlib.h zconf.h
+deflate.o: deflate.h zutil.h zlib.h zconf.h
+example.o: zlib.h zconf.h
+gzclose.o: zlib.h zconf.h gzguts.h
+gzlib.o: zlib.h zconf.h gzguts.h
+gzread.o: zlib.h zconf.h gzguts.h
+gzwrite.o: zlib.h zconf.h gzguts.h
+inffast.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+inflate.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+infback.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+inftrees.o: zutil.h zlib.h zconf.h inftrees.h
+minigzip.o: zlib.h zconf.h
+trees.o: deflate.h zutil.h zlib.h zconf.h trees.h
+uncompr.o: zlib.h zconf.h
+zutil.o: zutil.h zlib.h zconf.h
diff --git a/xs/src/png/zlib/compress.c b/xs/src/png/zlib/compress.c
new file mode 100644
index 000000000..e2db404ab
--- /dev/null
+++ b/xs/src/png/zlib/compress.c
@@ -0,0 +1,86 @@
+/* compress.c -- compress a memory buffer
+ * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#define ZLIB_INTERNAL
+#include "zlib.h"
+
+/* ===========================================================================
+     Compresses the source buffer into the destination buffer. The level
+   parameter has the same meaning as in deflateInit.  sourceLen is the byte
+   length of the source buffer. Upon entry, destLen is the total size of the
+   destination buffer, which must be at least 0.1% larger than sourceLen plus
+   12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
+
+     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+   Z_STREAM_ERROR if the level parameter is invalid.
+*/
+int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong sourceLen;
+    int level;
+{
+    z_stream stream;
+    int err;
+    const uInt max = (uInt)-1;
+    uLong left;
+
+    left = *destLen;
+    *destLen = 0;
+
+    stream.zalloc = (alloc_func)0;
+    stream.zfree = (free_func)0;
+    stream.opaque = (voidpf)0;
+
+    err = deflateInit(&stream, level);
+    if (err != Z_OK) return err;
+
+    stream.next_out = dest;
+    stream.avail_out = 0;
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
+            sourceLen -= stream.avail_in;
+        }
+        err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
+    } while (err == Z_OK);
+
+    *destLen = stream.total_out;
+    deflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK : err;
+}
+
+/* ===========================================================================
+ */
+int ZEXPORT compress (dest, destLen, source, sourceLen)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong sourceLen;
+{
+    return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
+}
+
+/* ===========================================================================
+     If the default memLevel or windowBits for deflateInit() is changed, then
+   this function needs to be updated.
+ */
+uLong ZEXPORT compressBound (sourceLen)
+    uLong sourceLen;
+{
+    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
+           (sourceLen >> 25) + 13;
+}
diff --git a/xs/src/png/zlib/configure b/xs/src/png/zlib/configure
new file mode 100644
index 000000000..e974d1fd7
--- /dev/null
+++ b/xs/src/png/zlib/configure
@@ -0,0 +1,921 @@
+#!/bin/sh
+# configure script for zlib.
+#
+# Normally configure builds both a static and a shared library.
+# If you want to build just a static library, use: ./configure --static
+#
+# To impose specific compiler or flags or install directory, use for example:
+#    prefix=$HOME CC=cc CFLAGS="-O4" ./configure
+# or for csh/tcsh users:
+#    (setenv prefix $HOME; setenv CC cc; setenv CFLAGS "-O4"; ./configure)
+
+# Incorrect settings of CC or CFLAGS may prevent creating a shared library.
+# If you have problems, try without defining CC and CFLAGS before reporting
+# an error.
+
+# start off configure.log
+echo -------------------- >> configure.log
+echo $0 $* >> configure.log
+date >> configure.log
+
+# get source directory
+SRCDIR=`dirname $0`
+if test $SRCDIR = "."; then
+    ZINC=""
+    ZINCOUT="-I."
+    SRCDIR=""
+else
+    ZINC='-include zconf.h'
+    ZINCOUT='-I. -I$(SRCDIR)'
+    SRCDIR="$SRCDIR/"
+fi
+
+# set command prefix for cross-compilation
+if [ -n "${CHOST}" ]; then
+    uname="`echo "${CHOST}" | sed -e 's/^[^-]*-\([^-]*\)$/\1/' -e 's/^[^-]*-[^-]*-\([^-]*\)$/\1/' -e 's/^[^-]*-[^-]*-\([^-]*\)-.*$/\1/'`"
+    CROSS_PREFIX="${CHOST}-"
+fi
+
+# destination name for static library
+STATICLIB=libz.a
+
+# extract zlib version numbers from zlib.h
+VER=`sed -n -e '/VERSION "/s/.*"\(.*\)".*/\1/p' < ${SRCDIR}zlib.h`
+VER3=`sed -n -e '/VERSION "/s/.*"\([0-9]*\\.[0-9]*\\.[0-9]*\).*/\1/p' < ${SRCDIR}zlib.h`
+VER2=`sed -n -e '/VERSION "/s/.*"\([0-9]*\\.[0-9]*\)\\..*/\1/p' < ${SRCDIR}zlib.h`
+VER1=`sed -n -e '/VERSION "/s/.*"\([0-9]*\)\\..*/\1/p' < ${SRCDIR}zlib.h`
+
+# establish commands for library building
+if "${CROSS_PREFIX}ar" --version >/dev/null 2>/dev/null || test $? -lt 126; then
+    AR=${AR-"${CROSS_PREFIX}ar"}
+    test -n "${CROSS_PREFIX}" && echo Using ${AR} | tee -a configure.log
+else
+    AR=${AR-"ar"}
+    test -n "${CROSS_PREFIX}" && echo Using ${AR} | tee -a configure.log
+fi
+ARFLAGS=${ARFLAGS-"rc"}
+if "${CROSS_PREFIX}ranlib" --version >/dev/null 2>/dev/null || test $? -lt 126; then
+    RANLIB=${RANLIB-"${CROSS_PREFIX}ranlib"}
+    test -n "${CROSS_PREFIX}" && echo Using ${RANLIB} | tee -a configure.log
+else
+    RANLIB=${RANLIB-"ranlib"}
+fi
+if "${CROSS_PREFIX}nm" --version >/dev/null 2>/dev/null || test $? -lt 126; then
+    NM=${NM-"${CROSS_PREFIX}nm"}
+    test -n "${CROSS_PREFIX}" && echo Using ${NM} | tee -a configure.log
+else
+    NM=${NM-"nm"}
+fi
+
+# set defaults before processing command line options
+LDCONFIG=${LDCONFIG-"ldconfig"}
+LDSHAREDLIBC="${LDSHAREDLIBC--lc}"
+ARCHS=
+prefix=${prefix-/usr/local}
+exec_prefix=${exec_prefix-'${prefix}'}
+libdir=${libdir-'${exec_prefix}/lib'}
+sharedlibdir=${sharedlibdir-'${libdir}'}
+includedir=${includedir-'${prefix}/include'}
+mandir=${mandir-'${prefix}/share/man'}
+shared_ext='.so'
+shared=1
+solo=0
+cover=0
+zprefix=0
+zconst=0
+build64=0
+gcc=0
+warn=0
+debug=0
+old_cc="$CC"
+old_cflags="$CFLAGS"
+OBJC='$(OBJZ) $(OBJG)'
+PIC_OBJC='$(PIC_OBJZ) $(PIC_OBJG)'
+
+# leave this script, optionally in a bad way
+leave()
+{
+  if test "$*" != "0"; then
+    echo "** $0 aborting." | tee -a configure.log
+  fi
+  rm -f $test.[co] $test $test$shared_ext $test.gcno ./--version
+  echo -------------------- >> configure.log
+  echo >> configure.log
+  echo >> configure.log
+  exit $1
+}
+
+# process command line options
+while test $# -ge 1
+do
+case "$1" in
+    -h* | --help)
+      echo 'usage:' | tee -a configure.log
+      echo '  configure [--const] [--zprefix] [--prefix=PREFIX]  [--eprefix=EXPREFIX]' | tee -a configure.log
+      echo '    [--static] [--64] [--libdir=LIBDIR] [--sharedlibdir=LIBDIR]' | tee -a configure.log
+      echo '    [--includedir=INCLUDEDIR] [--archs="-arch i386 -arch x86_64"]' | tee -a configure.log
+        exit 0 ;;
+    -p*=* | --prefix=*) prefix=`echo $1 | sed 's/.*=//'`; shift ;;
+    -e*=* | --eprefix=*) exec_prefix=`echo $1 | sed 's/.*=//'`; shift ;;
+    -l*=* | --libdir=*) libdir=`echo $1 | sed 's/.*=//'`; shift ;;
+    --sharedlibdir=*) sharedlibdir=`echo $1 | sed 's/.*=//'`; shift ;;
+    -i*=* | --includedir=*) includedir=`echo $1 | sed 's/.*=//'`;shift ;;
+    -u*=* | --uname=*) uname=`echo $1 | sed 's/.*=//'`;shift ;;
+    -p* | --prefix) prefix="$2"; shift; shift ;;
+    -e* | --eprefix) exec_prefix="$2"; shift; shift ;;
+    -l* | --libdir) libdir="$2"; shift; shift ;;
+    -i* | --includedir) includedir="$2"; shift; shift ;;
+    -s* | --shared | --enable-shared) shared=1; shift ;;
+    -t | --static) shared=0; shift ;;
+    --solo) solo=1; shift ;;
+    --cover) cover=1; shift ;;
+    -z* | --zprefix) zprefix=1; shift ;;
+    -6* | --64) build64=1; shift ;;
+    -a*=* | --archs=*) ARCHS=`echo $1 | sed 's/.*=//'`; shift ;;
+    --sysconfdir=*) echo "ignored option: --sysconfdir" | tee -a configure.log; shift ;;
+    --localstatedir=*) echo "ignored option: --localstatedir" | tee -a configure.log; shift ;;
+    -c* | --const) zconst=1; shift ;;
+    -w* | --warn) warn=1; shift ;;
+    -d* | --debug) debug=1; shift ;;
+    *)
+      echo "unknown option: $1" | tee -a configure.log
+      echo "$0 --help for help" | tee -a configure.log
+      leave 1;;
+    esac
+done
+
+# temporary file name
+test=ztest$$
+
+# put arguments in log, also put test file in log if used in arguments
+show()
+{
+  case "$*" in
+    *$test.c*)
+      echo === $test.c === >> configure.log
+      cat $test.c >> configure.log
+      echo === >> configure.log;;
+  esac
+  echo $* >> configure.log
+}
+
+# check for gcc vs. cc and set compile and link flags based on the system identified by uname
+cat > $test.c <<EOF
+extern int getchar();
+int hello() {return getchar();}
+EOF
+
+test -z "$CC" && echo Checking for ${CROSS_PREFIX}gcc... | tee -a configure.log
+cc=${CC-${CROSS_PREFIX}gcc}
+cflags=${CFLAGS-"-O3"}
+# to force the asm version use: CFLAGS="-O3 -DASMV" ./configure
+case "$cc" in
+  *gcc*) gcc=1 ;;
+  *clang*) gcc=1 ;;
+esac
+case `$cc -v 2>&1` in
+  *gcc*) gcc=1 ;;
+  *clang*) gcc=1 ;;
+esac
+
+show $cc -c $test.c
+if test "$gcc" -eq 1 && ($cc -c $test.c) >> configure.log 2>&1; then
+  echo ... using gcc >> configure.log
+  CC="$cc"
+  CFLAGS="${CFLAGS--O3}"
+  SFLAGS="${CFLAGS--O3} -fPIC"
+  if test "$ARCHS"; then
+    CFLAGS="${CFLAGS} ${ARCHS}"
+    LDFLAGS="${LDFLAGS} ${ARCHS}"
+  fi
+  if test $build64 -eq 1; then
+    CFLAGS="${CFLAGS} -m64"
+    SFLAGS="${SFLAGS} -m64"
+  fi
+  if test "$warn" -eq 1; then
+    if test "$zconst" -eq 1; then
+      CFLAGS="${CFLAGS} -Wall -Wextra -Wcast-qual -pedantic -DZLIB_CONST"
+    else
+      CFLAGS="${CFLAGS} -Wall -Wextra -pedantic"
+    fi
+  fi
+  if test $debug -eq 1; then
+    CFLAGS="${CFLAGS} -DZLIB_DEBUG"
+    SFLAGS="${SFLAGS} -DZLIB_DEBUG"
+  fi
+  if test -z "$uname"; then
+    uname=`(uname -s || echo unknown) 2>/dev/null`
+  fi
+  case "$uname" in
+  Linux* | linux* | GNU | GNU/* | solaris*)
+        LDSHARED=${LDSHARED-"$cc -shared -Wl,-soname,libz.so.1,--version-script,${SRCDIR}zlib.map"} ;;
+  *BSD | *bsd* | DragonFly)
+        LDSHARED=${LDSHARED-"$cc -shared -Wl,-soname,libz.so.1,--version-script,${SRCDIR}zlib.map"}
+        LDCONFIG="ldconfig -m" ;;
+  CYGWIN* | Cygwin* | cygwin* | OS/2*)
+        EXE='.exe' ;;
+  MINGW* | mingw*)
+# temporary bypass
+        rm -f $test.[co] $test $test$shared_ext
+        echo "Please use win32/Makefile.gcc instead." | tee -a configure.log
+        leave 1
+        LDSHARED=${LDSHARED-"$cc -shared"}
+        LDSHAREDLIBC=""
+        EXE='.exe' ;;
+  QNX*)  # This is for QNX6. I suppose that the QNX rule below is for QNX2,QNX4
+         # (alain.bonnefoy@icbt.com)
+                 LDSHARED=${LDSHARED-"$cc -shared -Wl,-hlibz.so.1"} ;;
+  HP-UX*)
+         LDSHARED=${LDSHARED-"$cc -shared $SFLAGS"}
+         case `(uname -m || echo unknown) 2>/dev/null` in
+         ia64)
+                 shared_ext='.so'
+                 SHAREDLIB='libz.so' ;;
+         *)
+                 shared_ext='.sl'
+                 SHAREDLIB='libz.sl' ;;
+         esac ;;
+  Darwin* | darwin*)
+             shared_ext='.dylib'
+             SHAREDLIB=libz$shared_ext
+             SHAREDLIBV=libz.$VER$shared_ext
+             SHAREDLIBM=libz.$VER1$shared_ext
+             LDSHARED=${LDSHARED-"$cc -dynamiclib -install_name $libdir/$SHAREDLIBM -compatibility_version $VER1 -current_version $VER3"}
+             if libtool -V 2>&1 | grep Apple > /dev/null; then
+                 AR="libtool"
+             else
+                 AR="/usr/bin/libtool"
+             fi
+             ARFLAGS="-o" ;;
+  *)             LDSHARED=${LDSHARED-"$cc -shared"} ;;
+  esac
+else
+  # find system name and corresponding cc options
+  CC=${CC-cc}
+  gcc=0
+  echo ... using $CC >> configure.log
+  if test -z "$uname"; then
+    uname=`(uname -sr || echo unknown) 2>/dev/null`
+  fi
+  case "$uname" in
+  HP-UX*)    SFLAGS=${CFLAGS-"-O +z"}
+             CFLAGS=${CFLAGS-"-O"}
+#            LDSHARED=${LDSHARED-"ld -b +vnocompatwarnings"}
+             LDSHARED=${LDSHARED-"ld -b"}
+         case `(uname -m || echo unknown) 2>/dev/null` in
+         ia64)
+             shared_ext='.so'
+             SHAREDLIB='libz.so' ;;
+         *)
+             shared_ext='.sl'
+             SHAREDLIB='libz.sl' ;;
+         esac ;;
+  IRIX*)     SFLAGS=${CFLAGS-"-ansi -O2 -rpath ."}
+             CFLAGS=${CFLAGS-"-ansi -O2"}
+             LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so.1"} ;;
+  OSF1\ V4*) SFLAGS=${CFLAGS-"-O -std1"}
+             CFLAGS=${CFLAGS-"-O -std1"}
+             LDFLAGS="${LDFLAGS} -Wl,-rpath,."
+             LDSHARED=${LDSHARED-"cc -shared  -Wl,-soname,libz.so -Wl,-msym -Wl,-rpath,$(libdir) -Wl,-set_version,${VER}:1.0"} ;;
+  OSF1*)     SFLAGS=${CFLAGS-"-O -std1"}
+             CFLAGS=${CFLAGS-"-O -std1"}
+             LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so.1"} ;;
+  QNX*)      SFLAGS=${CFLAGS-"-4 -O"}
+             CFLAGS=${CFLAGS-"-4 -O"}
+             LDSHARED=${LDSHARED-"cc"}
+             RANLIB=${RANLIB-"true"}
+             AR="cc"
+             ARFLAGS="-A" ;;
+  SCO_SV\ 3.2*) SFLAGS=${CFLAGS-"-O3 -dy -KPIC "}
+             CFLAGS=${CFLAGS-"-O3"}
+             LDSHARED=${LDSHARED-"cc -dy -KPIC -G"} ;;
+  SunOS\ 5* | solaris*)
+         LDSHARED=${LDSHARED-"cc -G -h libz$shared_ext.$VER1"}
+         SFLAGS=${CFLAGS-"-fast -KPIC"}
+         CFLAGS=${CFLAGS-"-fast"}
+         if test $build64 -eq 1; then
+             # old versions of SunPRO/Workshop/Studio don't support -m64,
+             # but newer ones do.  Check for it.
+             flag64=`$CC -flags | egrep -- '^-m64'`
+             if test x"$flag64" != x"" ; then
+                 CFLAGS="${CFLAGS} -m64"
+                 SFLAGS="${SFLAGS} -m64"
+             else
+                 case `(uname -m || echo unknown) 2>/dev/null` in
+                   i86*)
+                     SFLAGS="$SFLAGS -xarch=amd64"
+                     CFLAGS="$CFLAGS -xarch=amd64" ;;
+                   *)
+                     SFLAGS="$SFLAGS -xarch=v9"
+                     CFLAGS="$CFLAGS -xarch=v9" ;;
+                 esac
+             fi
+         fi
+         if test -n "$ZINC"; then
+             ZINC='-I- -I. -I$(SRCDIR)'
+         fi
+         ;;
+  SunOS\ 4*) SFLAGS=${CFLAGS-"-O2 -PIC"}
+             CFLAGS=${CFLAGS-"-O2"}
+             LDSHARED=${LDSHARED-"ld"} ;;
+  SunStudio\ 9*) SFLAGS=${CFLAGS-"-fast -xcode=pic32 -xtarget=ultra3 -xarch=v9b"}
+             CFLAGS=${CFLAGS-"-fast -xtarget=ultra3 -xarch=v9b"}
+             LDSHARED=${LDSHARED-"cc -xarch=v9b"} ;;
+  UNIX_System_V\ 4.2.0)
+             SFLAGS=${CFLAGS-"-KPIC -O"}
+             CFLAGS=${CFLAGS-"-O"}
+             LDSHARED=${LDSHARED-"cc -G"} ;;
+  UNIX_SV\ 4.2MP)
+             SFLAGS=${CFLAGS-"-Kconform_pic -O"}
+             CFLAGS=${CFLAGS-"-O"}
+             LDSHARED=${LDSHARED-"cc -G"} ;;
+  OpenUNIX\ 5)
+             SFLAGS=${CFLAGS-"-KPIC -O"}
+             CFLAGS=${CFLAGS-"-O"}
+             LDSHARED=${LDSHARED-"cc -G"} ;;
+  AIX*)  # Courtesy of dbakker@arrayasolutions.com
+             SFLAGS=${CFLAGS-"-O -qmaxmem=8192"}
+             CFLAGS=${CFLAGS-"-O -qmaxmem=8192"}
+             LDSHARED=${LDSHARED-"xlc -G"} ;;
+  # send working options for other systems to zlib@gzip.org
+  *)         SFLAGS=${CFLAGS-"-O"}
+             CFLAGS=${CFLAGS-"-O"}
+             LDSHARED=${LDSHARED-"cc -shared"} ;;
+  esac
+fi
+
+# destination names for shared library if not defined above
+SHAREDLIB=${SHAREDLIB-"libz$shared_ext"}
+SHAREDLIBV=${SHAREDLIBV-"libz$shared_ext.$VER"}
+SHAREDLIBM=${SHAREDLIBM-"libz$shared_ext.$VER1"}
+
+echo >> configure.log
+
+# define functions for testing compiler and library characteristics and logging the results
+
+cat > $test.c <<EOF
+#error error
+EOF
+if ($CC -c $CFLAGS $test.c) 2>/dev/null; then
+  try()
+  {
+    show $*
+    test "`( $* ) 2>&1 | tee -a configure.log`" = ""
+  }
+  echo - using any output from compiler to indicate an error >> configure.log
+else
+  try()
+  {
+    show $*
+    ( $* ) >> configure.log 2>&1
+    ret=$?
+    if test $ret -ne 0; then
+      echo "(exit code "$ret")" >> configure.log
+    fi
+    return $ret
+  }
+fi
+
+tryboth()
+{
+  show $*
+  got=`( $* ) 2>&1`
+  ret=$?
+  printf %s "$got" >> configure.log
+  if test $ret -ne 0; then
+    return $ret
+  fi
+  test "$got" = ""
+}
+
+cat > $test.c << EOF
+int foo() { return 0; }
+EOF
+echo "Checking for obsessive-compulsive compiler options..." >> configure.log
+if try $CC -c $CFLAGS $test.c; then
+  :
+else
+  echo "Compiler error reporting is too harsh for $0 (perhaps remove -Werror)." | tee -a configure.log
+  leave 1
+fi
+
+echo >> configure.log
+
+# see if shared library build supported
+cat > $test.c <<EOF
+extern int getchar();
+int hello() {return getchar();}
+EOF
+if test $shared -eq 1; then
+  echo Checking for shared library support... | tee -a configure.log
+  # we must test in two steps (cc then ld), required at least on SunOS 4.x
+  if try $CC -w -c $SFLAGS $test.c &&
+     try $LDSHARED $SFLAGS -o $test$shared_ext $test.o; then
+    echo Building shared library $SHAREDLIBV with $CC. | tee -a configure.log
+  elif test -z "$old_cc" -a -z "$old_cflags"; then
+    echo No shared library support. | tee -a configure.log
+    shared=0;
+  else
+    echo 'No shared library support; try without defining CC and CFLAGS' | tee -a configure.log
+    shared=0;
+  fi
+fi
+if test $shared -eq 0; then
+  LDSHARED="$CC"
+  ALL="static"
+  TEST="all teststatic"
+  SHAREDLIB=""
+  SHAREDLIBV=""
+  SHAREDLIBM=""
+  echo Building static library $STATICLIB version $VER with $CC. | tee -a configure.log
+else
+  ALL="static shared"
+  TEST="all teststatic testshared"
+fi
+
+# check for underscores in external names for use by assembler code
+CPP=${CPP-"$CC -E"}
+case $CFLAGS in
+  *ASMV*)
+    echo >> configure.log
+    show "$NM $test.o | grep _hello"
+    if test "`$NM $test.o | grep _hello | tee -a configure.log`" = ""; then
+      CPP="$CPP -DNO_UNDERLINE"
+      echo Checking for underline in external names... No. | tee -a configure.log
+    else
+      echo Checking for underline in external names... Yes. | tee -a configure.log
+    fi ;;
+esac
+
+echo >> configure.log
+
+# check for size_t
+cat > $test.c <<EOF
+#include <stdio.h>
+#include <stdlib.h>
+size_t dummy = 0;
+EOF
+if try $CC -c $CFLAGS $test.c; then
+  echo "Checking for size_t... Yes." | tee -a configure.log
+  need_sizet=0
+else
+  echo "Checking for size_t... No." | tee -a configure.log
+  need_sizet=1
+fi
+
+echo >> configure.log
+
+# find the size_t integer type, if needed
+if test $need_sizet -eq 1; then
+  cat > $test.c <<EOF
+long long dummy = 0;
+EOF
+  if try $CC -c $CFLAGS $test.c; then
+    echo "Checking for long long... Yes." | tee -a configure.log
+    cat > $test.c <<EOF
+#include <stdio.h>
+int main(void) {
+    if (sizeof(void *) <= sizeof(int)) puts("int");
+    else if (sizeof(void *) <= sizeof(long)) puts("long");
+    else puts("z_longlong");
+    return 0;
+}
+EOF
+  else
+    echo "Checking for long long... No." | tee -a configure.log
+    cat > $test.c <<EOF
+#include <stdio.h>
+int main(void) {
+    if (sizeof(void *) <= sizeof(int)) puts("int");
+    else puts("long");
+    return 0;
+}
+EOF
+  fi
+  if try $CC $CFLAGS -o $test $test.c; then
+    sizet=`./$test`
+    echo "Checking for a pointer-size integer type..." $sizet"." | tee -a configure.log
+  else
+    echo "Failed to find a pointer-size integer type." | tee -a configure.log
+    leave 1
+  fi
+fi
+
+if test $need_sizet -eq 1; then
+  CFLAGS="${CFLAGS} -DNO_SIZE_T=${sizet}"
+  SFLAGS="${SFLAGS} -DNO_SIZE_T=${sizet}"
+fi
+
+echo >> configure.log
+
+# check for large file support, and if none, check for fseeko()
+cat > $test.c <<EOF
+#include <sys/types.h>
+off64_t dummy = 0;
+EOF
+if try $CC -c $CFLAGS -D_LARGEFILE64_SOURCE=1 $test.c; then
+  CFLAGS="${CFLAGS} -D_LARGEFILE64_SOURCE=1"
+  SFLAGS="${SFLAGS} -D_LARGEFILE64_SOURCE=1"
+  ALL="${ALL} all64"
+  TEST="${TEST} test64"
+  echo "Checking for off64_t... Yes." | tee -a configure.log
+  echo "Checking for fseeko... Yes." | tee -a configure.log
+else
+  echo "Checking for off64_t... No." | tee -a configure.log
+  echo >> configure.log
+  cat > $test.c <<EOF
+#include <stdio.h>
+int main(void) {
+  fseeko(NULL, 0, 0);
+  return 0;
+}
+EOF
+  if try $CC $CFLAGS -o $test $test.c; then
+    echo "Checking for fseeko... Yes." | tee -a configure.log
+  else
+    CFLAGS="${CFLAGS} -DNO_FSEEKO"
+    SFLAGS="${SFLAGS} -DNO_FSEEKO"
+    echo "Checking for fseeko... No." | tee -a configure.log
+  fi
+fi
+
+echo >> configure.log
+
+# check for strerror() for use by gz* functions
+cat > $test.c <<EOF
+#include <string.h>
+#include <errno.h>
+int main() { return strlen(strerror(errno)); }
+EOF
+if try $CC $CFLAGS -o $test $test.c; then
+  echo "Checking for strerror... Yes." | tee -a configure.log
+else
+  CFLAGS="${CFLAGS} -DNO_STRERROR"
+  SFLAGS="${SFLAGS} -DNO_STRERROR"
+  echo "Checking for strerror... No." | tee -a configure.log
+fi
+
+# copy clean zconf.h for subsequent edits
+cp -p ${SRCDIR}zconf.h.in zconf.h
+
+echo >> configure.log
+
+# check for unistd.h and save result in zconf.h
+cat > $test.c <<EOF
+#include <unistd.h>
+int main() { return 0; }
+EOF
+if try $CC -c $CFLAGS $test.c; then
+  sed < zconf.h "/^#ifdef HAVE_UNISTD_H.* may be/s/def HAVE_UNISTD_H\(.*\) may be/ 1\1 was/" > zconf.temp.h
+  mv zconf.temp.h zconf.h
+  echo "Checking for unistd.h... Yes." | tee -a configure.log
+else
+  echo "Checking for unistd.h... No." | tee -a configure.log
+fi
+
+echo >> configure.log
+
+# check for stdarg.h and save result in zconf.h
+cat > $test.c <<EOF
+#include <stdarg.h>
+int main() { return 0; }
+EOF
+if try $CC -c $CFLAGS $test.c; then
+  sed < zconf.h "/^#ifdef HAVE_STDARG_H.* may be/s/def HAVE_STDARG_H\(.*\) may be/ 1\1 was/" > zconf.temp.h
+  mv zconf.temp.h zconf.h
+  echo "Checking for stdarg.h... Yes." | tee -a configure.log
+else
+  echo "Checking for stdarg.h... No." | tee -a configure.log
+fi
+
+# if the z_ prefix was requested, save that in zconf.h
+if test $zprefix -eq 1; then
+  sed < zconf.h "/#ifdef Z_PREFIX.* may be/s/def Z_PREFIX\(.*\) may be/ 1\1 was/" > zconf.temp.h
+  mv zconf.temp.h zconf.h
+  echo >> configure.log
+  echo "Using z_ prefix on all symbols." | tee -a configure.log
+fi
+
+# if --solo compilation was requested, save that in zconf.h and remove gz stuff from object lists
+if test $solo -eq 1; then
+  sed '/#define ZCONF_H/a\
+#define Z_SOLO
+
+' < zconf.h > zconf.temp.h
+  mv zconf.temp.h zconf.h
+OBJC='$(OBJZ)'
+PIC_OBJC='$(PIC_OBJZ)'
+fi
+
+# if code coverage testing was requested, use older gcc if defined, e.g. "gcc-4.2" on Mac OS X
+if test $cover -eq 1; then
+  CFLAGS="${CFLAGS} -fprofile-arcs -ftest-coverage"
+  if test -n "$GCC_CLASSIC"; then
+    CC=$GCC_CLASSIC
+  fi
+fi
+
+echo >> configure.log
+
+# conduct a series of tests to resolve eight possible cases of using "vs" or "s" printf functions
+# (using stdarg or not), with or without "n" (proving size of buffer), and with or without a
+# return value.  The most secure result is vsnprintf() with a return value.  snprintf() with a
+# return value is secure as well, but then gzprintf() will be limited to 20 arguments.
+cat > $test.c <<EOF
+#include <stdio.h>
+#include <stdarg.h>
+#include "zconf.h"
+int main()
+{
+#ifndef STDC
+  choke me
+#endif
+  return 0;
+}
+EOF
+if try $CC -c $CFLAGS $test.c; then
+  echo "Checking whether to use vs[n]printf() or s[n]printf()... using vs[n]printf()." | tee -a configure.log
+
+  echo >> configure.log
+  cat > $test.c <<EOF
+#include <stdio.h>
+#include <stdarg.h>
+int mytest(const char *fmt, ...)
+{
+  char buf[20];
+  va_list ap;
+  va_start(ap, fmt);
+  vsnprintf(buf, sizeof(buf), fmt, ap);
+  va_end(ap);
+  return 0;
+}
+int main()
+{
+  return (mytest("Hello%d\n", 1));
+}
+EOF
+  if try $CC $CFLAGS -o $test $test.c; then
+    echo "Checking for vsnprintf() in stdio.h... Yes." | tee -a configure.log
+
+    echo >> configure.log
+    cat >$test.c <<EOF
+#include <stdio.h>
+#include <stdarg.h>
+int mytest(const char *fmt, ...)
+{
+  int n;
+  char buf[20];
+  va_list ap;
+  va_start(ap, fmt);
+  n = vsnprintf(buf, sizeof(buf), fmt, ap);
+  va_end(ap);
+  return n;
+}
+int main()
+{
+  return (mytest("Hello%d\n", 1));
+}
+EOF
+
+    if try $CC -c $CFLAGS $test.c; then
+      echo "Checking for return value of vsnprintf()... Yes." | tee -a configure.log
+    else
+      CFLAGS="$CFLAGS -DHAS_vsnprintf_void"
+      SFLAGS="$SFLAGS -DHAS_vsnprintf_void"
+      echo "Checking for return value of vsnprintf()... No." | tee -a configure.log
+      echo "  WARNING: apparently vsnprintf() does not return a value. zlib" | tee -a configure.log
+      echo "  can build but will be open to possible string-format security" | tee -a configure.log
+      echo "  vulnerabilities." | tee -a configure.log
+    fi
+  else
+    CFLAGS="$CFLAGS -DNO_vsnprintf"
+    SFLAGS="$SFLAGS -DNO_vsnprintf"
+    echo "Checking for vsnprintf() in stdio.h... No." | tee -a configure.log
+    echo "  WARNING: vsnprintf() not found, falling back to vsprintf(). zlib" | tee -a configure.log
+    echo "  can build but will be open to possible buffer-overflow security" | tee -a configure.log
+    echo "  vulnerabilities." | tee -a configure.log
+
+    echo >> configure.log
+    cat >$test.c <<EOF
+#include <stdio.h>
+#include <stdarg.h>
+int mytest(const char *fmt, ...)
+{
+  int n;
+  char buf[20];
+  va_list ap;
+  va_start(ap, fmt);
+  n = vsprintf(buf, fmt, ap);
+  va_end(ap);
+  return n;
+}
+int main()
+{
+  return (mytest("Hello%d\n", 1));
+}
+EOF
+
+    if try $CC -c $CFLAGS $test.c; then
+      echo "Checking for return value of vsprintf()... Yes." | tee -a configure.log
+    else
+      CFLAGS="$CFLAGS -DHAS_vsprintf_void"
+      SFLAGS="$SFLAGS -DHAS_vsprintf_void"
+      echo "Checking for return value of vsprintf()... No." | tee -a configure.log
+      echo "  WARNING: apparently vsprintf() does not return a value. zlib" | tee -a configure.log
+      echo "  can build but will be open to possible string-format security" | tee -a configure.log
+      echo "  vulnerabilities." | tee -a configure.log
+    fi
+  fi
+else
+  echo "Checking whether to use vs[n]printf() or s[n]printf()... using s[n]printf()." | tee -a configure.log
+
+  echo >> configure.log
+  cat >$test.c <<EOF
+#include <stdio.h>
+int mytest()
+{
+  char buf[20];
+  snprintf(buf, sizeof(buf), "%s", "foo");
+  return 0;
+}
+int main()
+{
+  return (mytest());
+}
+EOF
+
+  if try $CC $CFLAGS -o $test $test.c; then
+    echo "Checking for snprintf() in stdio.h... Yes." | tee -a configure.log
+
+    echo >> configure.log
+    cat >$test.c <<EOF
+#include <stdio.h>
+int mytest()
+{
+  char buf[20];
+  return snprintf(buf, sizeof(buf), "%s", "foo");
+}
+int main()
+{
+  return (mytest());
+}
+EOF
+
+    if try $CC -c $CFLAGS $test.c; then
+      echo "Checking for return value of snprintf()... Yes." | tee -a configure.log
+    else
+      CFLAGS="$CFLAGS -DHAS_snprintf_void"
+      SFLAGS="$SFLAGS -DHAS_snprintf_void"
+      echo "Checking for return value of snprintf()... No." | tee -a configure.log
+      echo "  WARNING: apparently snprintf() does not return a value. zlib" | tee -a configure.log
+      echo "  can build but will be open to possible string-format security" | tee -a configure.log
+      echo "  vulnerabilities." | tee -a configure.log
+    fi
+  else
+    CFLAGS="$CFLAGS -DNO_snprintf"
+    SFLAGS="$SFLAGS -DNO_snprintf"
+    echo "Checking for snprintf() in stdio.h... No." | tee -a configure.log
+    echo "  WARNING: snprintf() not found, falling back to sprintf(). zlib" | tee -a configure.log
+    echo "  can build but will be open to possible buffer-overflow security" | tee -a configure.log
+    echo "  vulnerabilities." | tee -a configure.log
+
+    echo >> configure.log
+    cat >$test.c <<EOF
+#include <stdio.h>
+int mytest()
+{
+  char buf[20];
+  return sprintf(buf, "%s", "foo");
+}
+int main()
+{
+  return (mytest());
+}
+EOF
+
+    if try $CC -c $CFLAGS $test.c; then
+      echo "Checking for return value of sprintf()... Yes." | tee -a configure.log
+    else
+      CFLAGS="$CFLAGS -DHAS_sprintf_void"
+      SFLAGS="$SFLAGS -DHAS_sprintf_void"
+      echo "Checking for return value of sprintf()... No." | tee -a configure.log
+      echo "  WARNING: apparently sprintf() does not return a value. zlib" | tee -a configure.log
+      echo "  can build but will be open to possible string-format security" | tee -a configure.log
+      echo "  vulnerabilities." | tee -a configure.log
+    fi
+  fi
+fi
+
+# see if we can hide zlib internal symbols that are linked between separate source files
+if test "$gcc" -eq 1; then
+  echo >> configure.log
+  cat > $test.c <<EOF
+#define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+int ZLIB_INTERNAL foo;
+int main()
+{
+  return 0;
+}
+EOF
+  if tryboth $CC -c $CFLAGS $test.c; then
+    CFLAGS="$CFLAGS -DHAVE_HIDDEN"
+    SFLAGS="$SFLAGS -DHAVE_HIDDEN"
+    echo "Checking for attribute(visibility) support... Yes." | tee -a configure.log
+  else
+    echo "Checking for attribute(visibility) support... No." | tee -a configure.log
+  fi
+fi
+
+# show the results in the log
+echo >> configure.log
+echo ALL = $ALL >> configure.log
+echo AR = $AR >> configure.log
+echo ARFLAGS = $ARFLAGS >> configure.log
+echo CC = $CC >> configure.log
+echo CFLAGS = $CFLAGS >> configure.log
+echo CPP = $CPP >> configure.log
+echo EXE = $EXE >> configure.log
+echo LDCONFIG = $LDCONFIG >> configure.log
+echo LDFLAGS = $LDFLAGS >> configure.log
+echo LDSHARED = $LDSHARED >> configure.log
+echo LDSHAREDLIBC = $LDSHAREDLIBC >> configure.log
+echo OBJC = $OBJC >> configure.log
+echo PIC_OBJC = $PIC_OBJC >> configure.log
+echo RANLIB = $RANLIB >> configure.log
+echo SFLAGS = $SFLAGS >> configure.log
+echo SHAREDLIB = $SHAREDLIB >> configure.log
+echo SHAREDLIBM = $SHAREDLIBM >> configure.log
+echo SHAREDLIBV = $SHAREDLIBV >> configure.log
+echo STATICLIB = $STATICLIB >> configure.log
+echo TEST = $TEST >> configure.log
+echo VER = $VER >> configure.log
+echo Z_U4 = $Z_U4 >> configure.log
+echo SRCDIR = $SRCDIR >> configure.log
+echo exec_prefix = $exec_prefix >> configure.log
+echo includedir = $includedir >> configure.log
+echo libdir = $libdir >> configure.log
+echo mandir = $mandir >> configure.log
+echo prefix = $prefix >> configure.log
+echo sharedlibdir = $sharedlibdir >> configure.log
+echo uname = $uname >> configure.log
+
+# udpate Makefile with the configure results
+sed < ${SRCDIR}Makefile.in "
+/^CC *=/s#=.*#=$CC#
+/^CFLAGS *=/s#=.*#=$CFLAGS#
+/^SFLAGS *=/s#=.*#=$SFLAGS#
+/^LDFLAGS *=/s#=.*#=$LDFLAGS#
+/^LDSHARED *=/s#=.*#=$LDSHARED#
+/^CPP *=/s#=.*#=$CPP#
+/^STATICLIB *=/s#=.*#=$STATICLIB#
+/^SHAREDLIB *=/s#=.*#=$SHAREDLIB#
+/^SHAREDLIBV *=/s#=.*#=$SHAREDLIBV#
+/^SHAREDLIBM *=/s#=.*#=$SHAREDLIBM#
+/^AR *=/s#=.*#=$AR#
+/^ARFLAGS *=/s#=.*#=$ARFLAGS#
+/^RANLIB *=/s#=.*#=$RANLIB#
+/^LDCONFIG *=/s#=.*#=$LDCONFIG#
+/^LDSHAREDLIBC *=/s#=.*#=$LDSHAREDLIBC#
+/^EXE *=/s#=.*#=$EXE#
+/^SRCDIR *=/s#=.*#=$SRCDIR#
+/^ZINC *=/s#=.*#=$ZINC#
+/^ZINCOUT *=/s#=.*#=$ZINCOUT#
+/^prefix *=/s#=.*#=$prefix#
+/^exec_prefix *=/s#=.*#=$exec_prefix#
+/^libdir *=/s#=.*#=$libdir#
+/^sharedlibdir *=/s#=.*#=$sharedlibdir#
+/^includedir *=/s#=.*#=$includedir#
+/^mandir *=/s#=.*#=$mandir#
+/^OBJC *=/s#=.*#= $OBJC#
+/^PIC_OBJC *=/s#=.*#= $PIC_OBJC#
+/^all: */s#:.*#: $ALL#
+/^test: */s#:.*#: $TEST#
+" > Makefile
+
+# create zlib.pc with the configure results
+sed < ${SRCDIR}zlib.pc.in "
+/^CC *=/s#=.*#=$CC#
+/^CFLAGS *=/s#=.*#=$CFLAGS#
+/^CPP *=/s#=.*#=$CPP#
+/^LDSHARED *=/s#=.*#=$LDSHARED#
+/^STATICLIB *=/s#=.*#=$STATICLIB#
+/^SHAREDLIB *=/s#=.*#=$SHAREDLIB#
+/^SHAREDLIBV *=/s#=.*#=$SHAREDLIBV#
+/^SHAREDLIBM *=/s#=.*#=$SHAREDLIBM#
+/^AR *=/s#=.*#=$AR#
+/^ARFLAGS *=/s#=.*#=$ARFLAGS#
+/^RANLIB *=/s#=.*#=$RANLIB#
+/^EXE *=/s#=.*#=$EXE#
+/^prefix *=/s#=.*#=$prefix#
+/^exec_prefix *=/s#=.*#=$exec_prefix#
+/^libdir *=/s#=.*#=$libdir#
+/^sharedlibdir *=/s#=.*#=$sharedlibdir#
+/^includedir *=/s#=.*#=$includedir#
+/^mandir *=/s#=.*#=$mandir#
+/^LDFLAGS *=/s#=.*#=$LDFLAGS#
+" | sed -e "
+s/\@VERSION\@/$VER/g;
+" > zlib.pc
+
+# done
+leave 0
diff --git a/xs/src/png/zlib/contrib/README.contrib b/xs/src/png/zlib/contrib/README.contrib
new file mode 100644
index 000000000..a411d5c39
--- /dev/null
+++ b/xs/src/png/zlib/contrib/README.contrib
@@ -0,0 +1,78 @@
+All files under this contrib directory are UNSUPPORTED. There were
+provided by users of zlib and were not tested by the authors of zlib.
+Use at your own risk. Please contact the authors of the contributions
+for help about these, not the zlib authors. Thanks.
+
+
+ada/        by Dmitriy Anisimkov <anisimkov@yahoo.com>
+        Support for Ada
+        See http://zlib-ada.sourceforge.net/
+
+amd64/      by Mikhail Teterin <mi@ALDAN.algebra.com>
+        asm code for AMD64
+        See patch at http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/96393
+
+asm686/     by Brian Raiter <breadbox@muppetlabs.com>
+        asm code for Pentium and PPro/PII, using the AT&T (GNU as) syntax
+        See http://www.muppetlabs.com/~breadbox/software/assembly.html
+
+blast/      by Mark Adler <madler@alumni.caltech.edu>
+        Decompressor for output of PKWare Data Compression Library (DCL)
+
+delphi/     by Cosmin Truta <cosmint@cs.ubbcluj.ro>
+        Support for Delphi and C++ Builder
+
+dotzlib/    by Henrik Ravn <henrik@ravn.com>
+        Support for Microsoft .Net and Visual C++ .Net
+
+gcc_gvmat64/by Gilles Vollant <info@winimage.com>
+        GCC Version of x86 64-bit (AMD64 and Intel EM64t) code for x64
+        assembler to replace longest_match() and inflate_fast()
+
+infback9/   by Mark Adler <madler@alumni.caltech.edu>
+        Unsupported diffs to infback to decode the deflate64 format
+
+inflate86/  by Chris Anderson <christop@charm.net>
+        Tuned x86 gcc asm code to replace inflate_fast()
+
+iostream/   by Kevin Ruland <kevin@rodin.wustl.edu>
+        A C++ I/O streams interface to the zlib gz* functions
+
+iostream2/  by Tyge Løvset <Tyge.Lovset@cmr.no>
+        Another C++ I/O streams interface
+
+iostream3/  by Ludwig Schwardt <schwardt@sun.ac.za>
+            and Kevin Ruland <kevin@rodin.wustl.edu>
+        Yet another C++ I/O streams interface
+
+masmx64/    by Gilles Vollant <info@winimage.com>
+        x86 64-bit (AMD64 and Intel EM64t) code for x64 assembler to
+        replace longest_match() and inflate_fast(),  also masm x86
+        64-bits translation of Chris Anderson inflate_fast()
+
+masmx86/    by Gilles Vollant <info@winimage.com>
+        x86 asm code to replace longest_match() and inflate_fast(),
+        for Visual C++ and MASM (32 bits).
+        Based on Brian Raiter (asm686) and Chris Anderson (inflate86)
+
+minizip/    by Gilles Vollant <info@winimage.com>
+        Mini zip and unzip based on zlib
+        Includes Zip64 support by Mathias Svensson <mathias@result42.com>
+        See http://www.winimage.com/zLibDll/minizip.html
+
+pascal/     by Bob Dellaca <bobdl@xtra.co.nz> et al.
+        Support for Pascal
+
+puff/       by Mark Adler <madler@alumni.caltech.edu>
+        Small, low memory usage inflate.  Also serves to provide an
+        unambiguous description of the deflate format.
+
+testzlib/   by Gilles Vollant <info@winimage.com>
+        Example of the use of zlib
+
+untgz/      by Pedro A. Aranda Gutierrez <paag@tid.es>
+        A very simple tar.gz file extractor using zlib
+
+vstudio/    by Gilles Vollant <info@winimage.com>
+        Building a minizip-enhanced zlib with Microsoft Visual Studio
+        Includes vc11 from kreuzerkrieg and vc12 from davispuh
diff --git a/xs/src/png/zlib/contrib/ada/buffer_demo.adb b/xs/src/png/zlib/contrib/ada/buffer_demo.adb
new file mode 100644
index 000000000..46b863810
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/buffer_demo.adb
@@ -0,0 +1,106 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2004 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+--
+--  $Id: buffer_demo.adb,v 1.3 2004/09/06 06:55:35 vagul Exp $
+
+--  This demo program provided by Dr Steve Sangwine <sjs@essex.ac.uk>
+--
+--  Demonstration of a problem with Zlib-Ada (already fixed) when a buffer
+--  of exactly the correct size is used for decompressed data, and the last
+--  few bytes passed in to Zlib are checksum bytes.
+
+--  This program compresses a string of text, and then decompresses the
+--  compressed text into a buffer of the same size as the original text.
+
+with Ada.Streams; use Ada.Streams;
+with Ada.Text_IO;
+
+with ZLib; use ZLib;
+
+procedure Buffer_Demo is
+   EOL  : Character renames ASCII.LF;
+   Text : constant String
+     := "Four score and seven years ago our fathers brought forth," & EOL &
+        "upon this continent, a new nation, conceived in liberty," & EOL &
+        "and dedicated to the proposition that `all men are created equal'.";
+
+   Source : Stream_Element_Array (1 .. Text'Length);
+   for Source'Address use Text'Address;
+
+begin
+   Ada.Text_IO.Put (Text);
+   Ada.Text_IO.New_Line;
+   Ada.Text_IO.Put_Line
+     ("Uncompressed size : " & Positive'Image (Text'Length) & " bytes");
+
+   declare
+      Compressed_Data : Stream_Element_Array (1 .. Text'Length);
+      L               : Stream_Element_Offset;
+   begin
+      Compress : declare
+         Compressor : Filter_Type;
+         I : Stream_Element_Offset;
+      begin
+         Deflate_Init (Compressor);
+
+         --  Compress the whole of T at once.
+
+         Translate (Compressor, Source, I, Compressed_Data, L, Finish);
+         pragma Assert (I = Source'Last);
+
+         Close (Compressor);
+
+         Ada.Text_IO.Put_Line
+           ("Compressed size :   "
+            & Stream_Element_Offset'Image (L) & " bytes");
+      end Compress;
+
+      --  Now we decompress the data, passing short blocks of data to Zlib
+      --  (because this demonstrates the problem - the last block passed will
+      --  contain checksum information and there will be no output, only a
+      --  check inside Zlib that the checksum is correct).
+
+      Decompress : declare
+         Decompressor : Filter_Type;
+
+         Uncompressed_Data : Stream_Element_Array (1 .. Text'Length);
+
+         Block_Size : constant := 4;
+         --  This makes sure that the last block contains
+         --  only Adler checksum data.
+
+         P : Stream_Element_Offset := Compressed_Data'First - 1;
+         O : Stream_Element_Offset;
+      begin
+         Inflate_Init (Decompressor);
+
+         loop
+            Translate
+              (Decompressor,
+               Compressed_Data
+                 (P + 1 .. Stream_Element_Offset'Min (P + Block_Size, L)),
+               P,
+               Uncompressed_Data
+                 (Total_Out (Decompressor) + 1 .. Uncompressed_Data'Last),
+               O,
+               No_Flush);
+
+               Ada.Text_IO.Put_Line
+                 ("Total in : " & Count'Image (Total_In (Decompressor)) &
+                  ", out : " & Count'Image (Total_Out (Decompressor)));
+
+               exit when P = L;
+         end loop;
+
+         Ada.Text_IO.New_Line;
+         Ada.Text_IO.Put_Line
+           ("Decompressed text matches original text : "
+             & Boolean'Image (Uncompressed_Data = Source));
+      end Decompress;
+   end;
+end Buffer_Demo;
diff --git a/xs/src/png/zlib/contrib/ada/mtest.adb b/xs/src/png/zlib/contrib/ada/mtest.adb
new file mode 100644
index 000000000..c4dfd080f
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/mtest.adb
@@ -0,0 +1,156 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+--  Continuous test for ZLib multithreading. If the test would fail
+--  we should provide thread safe allocation routines for the Z_Stream.
+--
+--  $Id: mtest.adb,v 1.4 2004/07/23 07:49:54 vagul Exp $
+
+with ZLib;
+with Ada.Streams;
+with Ada.Numerics.Discrete_Random;
+with Ada.Text_IO;
+with Ada.Exceptions;
+with Ada.Task_Identification;
+
+procedure MTest is
+   use Ada.Streams;
+   use ZLib;
+
+   Stop : Boolean := False;
+
+   pragma Atomic (Stop);
+
+   subtype Visible_Symbols is Stream_Element range 16#20# .. 16#7E#;
+
+   package Random_Elements is
+      new Ada.Numerics.Discrete_Random (Visible_Symbols);
+
+   task type Test_Task;
+
+   task body Test_Task is
+      Buffer : Stream_Element_Array (1 .. 100_000);
+      Gen : Random_Elements.Generator;
+
+      Buffer_First  : Stream_Element_Offset;
+      Compare_First : Stream_Element_Offset;
+
+      Deflate : Filter_Type;
+      Inflate : Filter_Type;
+
+      procedure Further (Item : in Stream_Element_Array);
+
+      procedure Read_Buffer
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset);
+
+      -------------
+      -- Further --
+      -------------
+
+      procedure Further (Item : in Stream_Element_Array) is
+
+         procedure Compare (Item : in Stream_Element_Array);
+
+         -------------
+         -- Compare --
+         -------------
+
+         procedure Compare (Item : in Stream_Element_Array) is
+            Next_First : Stream_Element_Offset := Compare_First + Item'Length;
+         begin
+            if Buffer (Compare_First .. Next_First - 1) /= Item then
+               raise Program_Error;
+            end if;
+
+            Compare_First := Next_First;
+         end Compare;
+
+         procedure Compare_Write is new ZLib.Write (Write => Compare);
+      begin
+         Compare_Write (Inflate, Item, No_Flush);
+      end Further;
+
+      -----------------
+      -- Read_Buffer --
+      -----------------
+
+      procedure Read_Buffer
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset)
+      is
+         Buff_Diff   : Stream_Element_Offset := Buffer'Last - Buffer_First;
+         Next_First : Stream_Element_Offset;
+      begin
+         if Item'Length <= Buff_Diff then
+            Last := Item'Last;
+
+            Next_First := Buffer_First + Item'Length;
+
+            Item := Buffer (Buffer_First .. Next_First - 1);
+
+            Buffer_First := Next_First;
+         else
+            Last := Item'First + Buff_Diff;
+            Item (Item'First .. Last) := Buffer (Buffer_First .. Buffer'Last);
+            Buffer_First := Buffer'Last + 1;
+         end if;
+      end Read_Buffer;
+
+      procedure Translate is new Generic_Translate
+                                   (Data_In  => Read_Buffer,
+                                    Data_Out => Further);
+
+   begin
+      Random_Elements.Reset (Gen);
+
+      Buffer := (others => 20);
+
+      Main : loop
+         for J in Buffer'Range loop
+            Buffer (J) := Random_Elements.Random (Gen);
+
+            Deflate_Init (Deflate);
+            Inflate_Init (Inflate);
+
+            Buffer_First  := Buffer'First;
+            Compare_First := Buffer'First;
+
+            Translate (Deflate);
+
+            if Compare_First /= Buffer'Last + 1 then
+               raise Program_Error;
+            end if;
+
+            Ada.Text_IO.Put_Line
+              (Ada.Task_Identification.Image
+                 (Ada.Task_Identification.Current_Task)
+               & Stream_Element_Offset'Image (J)
+               & ZLib.Count'Image (Total_Out (Deflate)));
+
+            Close (Deflate);
+            Close (Inflate);
+
+            exit Main when Stop;
+         end loop;
+      end loop Main;
+   exception
+      when E : others =>
+         Ada.Text_IO.Put_Line (Ada.Exceptions.Exception_Information (E));
+         Stop := True;
+   end Test_Task;
+
+   Test : array (1 .. 4) of Test_Task;
+
+   pragma Unreferenced (Test);
+
+   Dummy : Character;
+
+begin
+   Ada.Text_IO.Get_Immediate (Dummy);
+   Stop := True;
+end MTest;
diff --git a/xs/src/png/zlib/contrib/ada/read.adb b/xs/src/png/zlib/contrib/ada/read.adb
new file mode 100644
index 000000000..1f2efbfeb
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/read.adb
@@ -0,0 +1,156 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: read.adb,v 1.8 2004/05/31 10:53:40 vagul Exp $
+
+--  Test/demo program for the generic read interface.
+
+with Ada.Numerics.Discrete_Random;
+with Ada.Streams;
+with Ada.Text_IO;
+
+with ZLib;
+
+procedure Read is
+
+   use Ada.Streams;
+
+   ------------------------------------
+   --  Test configuration parameters --
+   ------------------------------------
+
+   File_Size   : Stream_Element_Offset := 100_000;
+
+   Continuous  : constant Boolean          := False;
+   --  If this constant is True, the test would be repeated again and again,
+   --  with increment File_Size for every iteration.
+
+   Header      : constant ZLib.Header_Type := ZLib.Default;
+   --  Do not use Header other than Default in ZLib versions 1.1.4 and older.
+
+   Init_Random : constant := 8;
+   --  We are using the same random sequence, in case of we catch bug,
+   --  so we would be able to reproduce it.
+
+   -- End --
+
+   Pack_Size : Stream_Element_Offset;
+   Offset    : Stream_Element_Offset;
+
+   Filter     : ZLib.Filter_Type;
+
+   subtype Visible_Symbols
+      is Stream_Element range 16#20# .. 16#7E#;
+
+   package Random_Elements is new
+      Ada.Numerics.Discrete_Random (Visible_Symbols);
+
+   Gen : Random_Elements.Generator;
+   Period  : constant Stream_Element_Offset := 200;
+   --  Period constant variable for random generator not to be very random.
+   --  Bigger period, harder random.
+
+   Read_Buffer : Stream_Element_Array (1 .. 2048);
+   Read_First  : Stream_Element_Offset;
+   Read_Last   : Stream_Element_Offset;
+
+   procedure Reset;
+
+   procedure Read
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset);
+   --  this procedure is for generic instantiation of
+   --  ZLib.Read
+   --  reading data from the File_In.
+
+   procedure Read is new ZLib.Read
+                           (Read,
+                            Read_Buffer,
+                            Rest_First => Read_First,
+                            Rest_Last  => Read_Last);
+
+   ----------
+   -- Read --
+   ----------
+
+   procedure Read
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset) is
+   begin
+      Last := Stream_Element_Offset'Min
+               (Item'Last,
+                Item'First + File_Size - Offset);
+
+      for J in Item'First .. Last loop
+         if J < Item'First + Period then
+            Item (J) := Random_Elements.Random (Gen);
+         else
+            Item (J) := Item (J - Period);
+         end if;
+
+         Offset   := Offset + 1;
+      end loop;
+   end Read;
+
+   -----------
+   -- Reset --
+   -----------
+
+   procedure Reset is
+   begin
+      Random_Elements.Reset (Gen, Init_Random);
+      Pack_Size := 0;
+      Offset := 1;
+      Read_First := Read_Buffer'Last + 1;
+      Read_Last  := Read_Buffer'Last;
+   end Reset;
+
+begin
+   Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);
+
+   loop
+      for Level in ZLib.Compression_Level'Range loop
+
+         Ada.Text_IO.Put ("Level ="
+            & ZLib.Compression_Level'Image (Level));
+
+         --  Deflate using generic instantiation.
+
+         ZLib.Deflate_Init
+               (Filter,
+                Level,
+                Header => Header);
+
+         Reset;
+
+         Ada.Text_IO.Put
+           (Stream_Element_Offset'Image (File_Size) & " ->");
+
+         loop
+            declare
+               Buffer : Stream_Element_Array (1 .. 1024);
+               Last   : Stream_Element_Offset;
+            begin
+               Read (Filter, Buffer, Last);
+
+               Pack_Size := Pack_Size + Last - Buffer'First + 1;
+
+               exit when Last < Buffer'Last;
+            end;
+         end loop;
+
+         Ada.Text_IO.Put_Line (Stream_Element_Offset'Image (Pack_Size));
+
+         ZLib.Close (Filter);
+      end loop;
+
+      exit when not Continuous;
+
+      File_Size := File_Size + 1;
+   end loop;
+end Read;
diff --git a/xs/src/png/zlib/contrib/ada/readme.txt b/xs/src/png/zlib/contrib/ada/readme.txt
new file mode 100644
index 000000000..ce4d2cadf
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/readme.txt
@@ -0,0 +1,65 @@
+                        ZLib for Ada thick binding (ZLib.Ada)
+                        Release 1.3
+
+ZLib.Ada is a thick binding interface to the popular ZLib data
+compression library, available at http://www.gzip.org/zlib/.
+It provides Ada-style access to the ZLib C library.
+
+
+        Here are the main changes since ZLib.Ada 1.2:
+
+- Attension: ZLib.Read generic routine have a initialization requirement
+  for Read_Last parameter now. It is a bit incompartible with previous version,
+  but extends functionality, we could use new parameters Allow_Read_Some and
+  Flush now.
+
+- Added Is_Open routines to ZLib and ZLib.Streams packages.
+
+- Add pragma Assert to check Stream_Element is 8 bit.
+
+- Fix extraction to buffer with exact known decompressed size. Error reported by
+  Steve Sangwine.
+
+- Fix definition of ULong (changed to unsigned_long), fix regression on 64 bits
+  computers. Patch provided by Pascal Obry.
+
+- Add Status_Error exception definition.
+
+- Add pragma Assertion that Ada.Streams.Stream_Element size is 8 bit.
+
+
+        How to build ZLib.Ada under GNAT
+
+You should have the ZLib library already build on your computer, before
+building ZLib.Ada. Make the directory of ZLib.Ada sources current and
+issue the command:
+
+  gnatmake test -largs -L<directory where libz.a is> -lz
+
+Or use the GNAT project file build for GNAT 3.15 or later:
+
+  gnatmake -Pzlib.gpr -L<directory where libz.a is>
+
+
+        How to build ZLib.Ada under Aonix ObjectAda for Win32 7.2.2
+
+1. Make a project with all *.ads and *.adb files from the distribution.
+2. Build the libz.a library from the ZLib C sources.
+3. Rename libz.a to z.lib.
+4. Add the library z.lib to the project.
+5. Add the libc.lib library from the ObjectAda distribution to the project.
+6. Build the executable using test.adb as a main procedure.
+
+
+        How to use ZLib.Ada
+
+The source files test.adb and read.adb are small demo programs that show
+the main functionality of ZLib.Ada.
+
+The routines from the package specifications are commented.
+
+
+Homepage: http://zlib-ada.sourceforge.net/
+Author: Dmitriy Anisimkov <anisimkov@yahoo.com>
+
+Contributors: Pascal Obry <pascal@obry.org>, Steve Sangwine <sjs@essex.ac.uk>
diff --git a/xs/src/png/zlib/contrib/ada/test.adb b/xs/src/png/zlib/contrib/ada/test.adb
new file mode 100644
index 000000000..90773acfa
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/test.adb
@@ -0,0 +1,463 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: test.adb,v 1.17 2003/08/12 12:13:30 vagul Exp $
+
+--  The program has a few aims.
+--  1. Test ZLib.Ada95 thick binding functionality.
+--  2. Show the example of use main functionality of the ZLib.Ada95 binding.
+--  3. Build this program automatically compile all ZLib.Ada95 packages under
+--     GNAT Ada95 compiler.
+
+with ZLib.Streams;
+with Ada.Streams.Stream_IO;
+with Ada.Numerics.Discrete_Random;
+
+with Ada.Text_IO;
+
+with Ada.Calendar;
+
+procedure Test is
+
+   use Ada.Streams;
+   use Stream_IO;
+
+   ------------------------------------
+   --  Test configuration parameters --
+   ------------------------------------
+
+   File_Size   : Count   := 100_000;
+   Continuous  : constant Boolean := False;
+
+   Header      : constant ZLib.Header_Type := ZLib.Default;
+                                              --  ZLib.None;
+                                              --  ZLib.Auto;
+                                              --  ZLib.GZip;
+   --  Do not use Header other then Default in ZLib versions 1.1.4
+   --  and older.
+
+   Strategy    : constant ZLib.Strategy_Type := ZLib.Default_Strategy;
+   Init_Random : constant := 10;
+
+   -- End --
+
+   In_File_Name  : constant String := "testzlib.in";
+   --  Name of the input file
+
+   Z_File_Name   : constant String := "testzlib.zlb";
+   --  Name of the compressed file.
+
+   Out_File_Name : constant String := "testzlib.out";
+   --  Name of the decompressed file.
+
+   File_In   : File_Type;
+   File_Out  : File_Type;
+   File_Back : File_Type;
+   File_Z    : ZLib.Streams.Stream_Type;
+
+   Filter : ZLib.Filter_Type;
+
+   Time_Stamp : Ada.Calendar.Time;
+
+   procedure Generate_File;
+   --  Generate file of spetsified size with some random data.
+   --  The random data is repeatable, for the good compression.
+
+   procedure Compare_Streams
+     (Left, Right : in out Root_Stream_Type'Class);
+   --  The procedure compearing data in 2 streams.
+   --  It is for compare data before and after compression/decompression.
+
+   procedure Compare_Files (Left, Right : String);
+   --  Compare files. Based on the Compare_Streams.
+
+   procedure Copy_Streams
+     (Source, Target : in out Root_Stream_Type'Class;
+      Buffer_Size    : in     Stream_Element_Offset := 1024);
+   --  Copying data from one stream to another. It is for test stream
+   --  interface of the library.
+
+   procedure Data_In
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset);
+   --  this procedure is for generic instantiation of
+   --  ZLib.Generic_Translate.
+   --  reading data from the File_In.
+
+   procedure Data_Out (Item : in Stream_Element_Array);
+   --  this procedure is for generic instantiation of
+   --  ZLib.Generic_Translate.
+   --  writing data to the File_Out.
+
+   procedure Stamp;
+   --  Store the timestamp to the local variable.
+
+   procedure Print_Statistic (Msg : String; Data_Size : ZLib.Count);
+   --  Print the time statistic with the message.
+
+   procedure Translate is new ZLib.Generic_Translate
+                                (Data_In  => Data_In,
+                                 Data_Out => Data_Out);
+   --  This procedure is moving data from File_In to File_Out
+   --  with compression or decompression, depend on initialization of
+   --  Filter parameter.
+
+   -------------------
+   -- Compare_Files --
+   -------------------
+
+   procedure Compare_Files (Left, Right : String) is
+      Left_File, Right_File : File_Type;
+   begin
+      Open (Left_File, In_File, Left);
+      Open (Right_File, In_File, Right);
+      Compare_Streams (Stream (Left_File).all, Stream (Right_File).all);
+      Close (Left_File);
+      Close (Right_File);
+   end Compare_Files;
+
+   ---------------------
+   -- Compare_Streams --
+   ---------------------
+
+   procedure Compare_Streams
+     (Left, Right : in out Ada.Streams.Root_Stream_Type'Class)
+   is
+      Left_Buffer, Right_Buffer : Stream_Element_Array (0 .. 16#FFF#);
+      Left_Last, Right_Last : Stream_Element_Offset;
+   begin
+      loop
+         Read (Left, Left_Buffer, Left_Last);
+         Read (Right, Right_Buffer, Right_Last);
+
+         if Left_Last /= Right_Last then
+            Ada.Text_IO.Put_Line ("Compare error :"
+              & Stream_Element_Offset'Image (Left_Last)
+              & " /= "
+              & Stream_Element_Offset'Image (Right_Last));
+
+            raise Constraint_Error;
+
+         elsif Left_Buffer (0 .. Left_Last)
+               /= Right_Buffer (0 .. Right_Last)
+         then
+            Ada.Text_IO.Put_Line ("ERROR: IN and OUT files is not equal.");
+            raise Constraint_Error;
+
+         end if;
+
+         exit when Left_Last < Left_Buffer'Last;
+      end loop;
+   end Compare_Streams;
+
+   ------------------
+   -- Copy_Streams --
+   ------------------
+
+   procedure Copy_Streams
+     (Source, Target : in out Ada.Streams.Root_Stream_Type'Class;
+      Buffer_Size    : in     Stream_Element_Offset := 1024)
+   is
+      Buffer : Stream_Element_Array (1 .. Buffer_Size);
+      Last   : Stream_Element_Offset;
+   begin
+      loop
+         Read  (Source, Buffer, Last);
+         Write (Target, Buffer (1 .. Last));
+
+         exit when Last < Buffer'Last;
+      end loop;
+   end Copy_Streams;
+
+   -------------
+   -- Data_In --
+   -------------
+
+   procedure Data_In
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset) is
+   begin
+      Read (File_In, Item, Last);
+   end Data_In;
+
+   --------------
+   -- Data_Out --
+   --------------
+
+   procedure Data_Out (Item : in Stream_Element_Array) is
+   begin
+      Write (File_Out, Item);
+   end Data_Out;
+
+   -------------------
+   -- Generate_File --
+   -------------------
+
+   procedure Generate_File is
+      subtype Visible_Symbols is Stream_Element range 16#20# .. 16#7E#;
+
+      package Random_Elements is
+         new Ada.Numerics.Discrete_Random (Visible_Symbols);
+
+      Gen    : Random_Elements.Generator;
+      Buffer : Stream_Element_Array := (1 .. 77 => 16#20#) & 10;
+
+      Buffer_Count : constant Count := File_Size / Buffer'Length;
+      --  Number of same buffers in the packet.
+
+      Density : constant Count := 30; --  from 0 to Buffer'Length - 2;
+
+      procedure Fill_Buffer (J, D : in Count);
+      --  Change the part of the buffer.
+
+      -----------------
+      -- Fill_Buffer --
+      -----------------
+
+      procedure Fill_Buffer (J, D : in Count) is
+      begin
+         for K in 0 .. D loop
+            Buffer
+              (Stream_Element_Offset ((J + K) mod (Buffer'Length - 1) + 1))
+             := Random_Elements.Random (Gen);
+
+         end loop;
+      end Fill_Buffer;
+
+   begin
+      Random_Elements.Reset (Gen, Init_Random);
+
+      Create (File_In, Out_File, In_File_Name);
+
+      Fill_Buffer (1, Buffer'Length - 2);
+
+      for J in 1 .. Buffer_Count loop
+         Write (File_In, Buffer);
+
+         Fill_Buffer (J, Density);
+      end loop;
+
+      --  fill remain size.
+
+      Write
+        (File_In,
+         Buffer
+           (1 .. Stream_Element_Offset
+                   (File_Size - Buffer'Length * Buffer_Count)));
+
+      Flush (File_In);
+      Close (File_In);
+   end Generate_File;
+
+   ---------------------
+   -- Print_Statistic --
+   ---------------------
+
+   procedure Print_Statistic (Msg : String; Data_Size : ZLib.Count) is
+      use Ada.Calendar;
+      use Ada.Text_IO;
+
+      package Count_IO is new Integer_IO (ZLib.Count);
+
+      Curr_Dur : Duration := Clock - Time_Stamp;
+   begin
+      Put (Msg);
+
+      Set_Col (20);
+      Ada.Text_IO.Put ("size =");
+
+      Count_IO.Put
+        (Data_Size,
+         Width => Stream_IO.Count'Image (File_Size)'Length);
+
+      Put_Line (" duration =" & Duration'Image (Curr_Dur));
+   end Print_Statistic;
+
+   -----------
+   -- Stamp --
+   -----------
+
+   procedure Stamp is
+   begin
+      Time_Stamp := Ada.Calendar.Clock;
+   end Stamp;
+
+begin
+   Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);
+
+   loop
+      Generate_File;
+
+      for Level in ZLib.Compression_Level'Range loop
+
+         Ada.Text_IO.Put_Line ("Level ="
+            & ZLib.Compression_Level'Image (Level));
+
+         --  Test generic interface.
+         Open   (File_In, In_File, In_File_Name);
+         Create (File_Out, Out_File, Z_File_Name);
+
+         Stamp;
+
+         --  Deflate using generic instantiation.
+
+         ZLib.Deflate_Init
+               (Filter   => Filter,
+                Level    => Level,
+                Strategy => Strategy,
+                Header   => Header);
+
+         Translate (Filter);
+         Print_Statistic ("Generic compress", ZLib.Total_Out (Filter));
+         ZLib.Close (Filter);
+
+         Close (File_In);
+         Close (File_Out);
+
+         Open   (File_In, In_File, Z_File_Name);
+         Create (File_Out, Out_File, Out_File_Name);
+
+         Stamp;
+
+         --  Inflate using generic instantiation.
+
+         ZLib.Inflate_Init (Filter, Header => Header);
+
+         Translate (Filter);
+         Print_Statistic ("Generic decompress", ZLib.Total_Out (Filter));
+
+         ZLib.Close (Filter);
+
+         Close (File_In);
+         Close (File_Out);
+
+         Compare_Files (In_File_Name, Out_File_Name);
+
+         --  Test stream interface.
+
+         --  Compress to the back stream.
+
+         Open   (File_In, In_File, In_File_Name);
+         Create (File_Back, Out_File, Z_File_Name);
+
+         Stamp;
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.Out_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => True,
+            Level           => Level,
+            Strategy        => Strategy,
+            Header          => Header);
+
+         Copy_Streams
+           (Source => Stream (File_In).all,
+            Target => File_Z);
+
+         --  Flushing internal buffers to the back stream.
+
+         ZLib.Streams.Flush (File_Z, ZLib.Finish);
+
+         Print_Statistic ("Write compress",
+                          ZLib.Streams.Write_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+
+         Close (File_In);
+         Close (File_Back);
+
+         --  Compare reading from original file and from
+         --  decompression stream.
+
+         Open (File_In,   In_File, In_File_Name);
+         Open (File_Back, In_File, Z_File_Name);
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.In_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => True,
+            Header          => Header);
+
+         Stamp;
+         Compare_Streams (Stream (File_In).all, File_Z);
+
+         Print_Statistic ("Read decompress",
+                          ZLib.Streams.Read_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+         Close (File_In);
+         Close (File_Back);
+
+         --  Compress by reading from compression stream.
+
+         Open (File_Back, In_File, In_File_Name);
+         Create (File_Out, Out_File, Z_File_Name);
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.In_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => False,
+            Level           => Level,
+            Strategy        => Strategy,
+            Header          => Header);
+
+         Stamp;
+         Copy_Streams
+           (Source => File_Z,
+            Target => Stream (File_Out).all);
+
+         Print_Statistic ("Read compress",
+                          ZLib.Streams.Read_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+
+         Close (File_Out);
+         Close (File_Back);
+
+         --  Decompress to decompression stream.
+
+         Open   (File_In,   In_File, Z_File_Name);
+         Create (File_Back, Out_File, Out_File_Name);
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.Out_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => False,
+            Header          => Header);
+
+         Stamp;
+
+         Copy_Streams
+           (Source => Stream (File_In).all,
+            Target => File_Z);
+
+         Print_Statistic ("Write decompress",
+                          ZLib.Streams.Write_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+         Close (File_In);
+         Close (File_Back);
+
+         Compare_Files (In_File_Name, Out_File_Name);
+      end loop;
+
+      Ada.Text_IO.Put_Line (Count'Image (File_Size) & " Ok.");
+
+      exit when not Continuous;
+
+      File_Size := File_Size + 1;
+   end loop;
+end Test;
diff --git a/xs/src/png/zlib/contrib/ada/zlib-streams.adb b/xs/src/png/zlib/contrib/ada/zlib-streams.adb
new file mode 100644
index 000000000..b6497bae2
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib-streams.adb
@@ -0,0 +1,225 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-streams.adb,v 1.10 2004/05/31 10:53:40 vagul Exp $
+
+with Ada.Unchecked_Deallocation;
+
+package body ZLib.Streams is
+
+   -----------
+   -- Close --
+   -----------
+
+   procedure Close (Stream : in out Stream_Type) is
+      procedure Free is new Ada.Unchecked_Deallocation
+         (Stream_Element_Array, Buffer_Access);
+   begin
+      if Stream.Mode = Out_Stream or Stream.Mode = Duplex then
+         --  We should flush the data written by the writer.
+
+         Flush (Stream, Finish);
+
+         Close (Stream.Writer);
+      end if;
+
+      if Stream.Mode = In_Stream or Stream.Mode = Duplex then
+         Close (Stream.Reader);
+         Free (Stream.Buffer);
+      end if;
+   end Close;
+
+   ------------
+   -- Create --
+   ------------
+
+   procedure Create
+     (Stream            :    out Stream_Type;
+      Mode              : in     Stream_Mode;
+      Back              : in     Stream_Access;
+      Back_Compressed   : in     Boolean;
+      Level             : in     Compression_Level := Default_Compression;
+      Strategy          : in     Strategy_Type     := Default_Strategy;
+      Header            : in     Header_Type       := Default;
+      Read_Buffer_Size  : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size;
+      Write_Buffer_Size : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size)
+   is
+
+      subtype Buffer_Subtype is Stream_Element_Array (1 .. Read_Buffer_Size);
+
+      procedure Init_Filter
+         (Filter   : in out Filter_Type;
+          Compress : in     Boolean);
+
+      -----------------
+      -- Init_Filter --
+      -----------------
+
+      procedure Init_Filter
+         (Filter   : in out Filter_Type;
+          Compress : in     Boolean) is
+      begin
+         if Compress then
+            Deflate_Init
+              (Filter, Level, Strategy, Header => Header);
+         else
+            Inflate_Init (Filter, Header => Header);
+         end if;
+      end Init_Filter;
+
+   begin
+      Stream.Back := Back;
+      Stream.Mode := Mode;
+
+      if Mode = Out_Stream or Mode = Duplex then
+         Init_Filter (Stream.Writer, Back_Compressed);
+         Stream.Buffer_Size := Write_Buffer_Size;
+      else
+         Stream.Buffer_Size := 0;
+      end if;
+
+      if Mode = In_Stream or Mode = Duplex then
+         Init_Filter (Stream.Reader, not Back_Compressed);
+
+         Stream.Buffer     := new Buffer_Subtype;
+         Stream.Rest_First := Stream.Buffer'Last + 1;
+         Stream.Rest_Last  := Stream.Buffer'Last;
+      end if;
+   end Create;
+
+   -----------
+   -- Flush --
+   -----------
+
+   procedure Flush
+     (Stream : in out Stream_Type;
+      Mode   : in     Flush_Mode := Sync_Flush)
+   is
+      Buffer : Stream_Element_Array (1 .. Stream.Buffer_Size);
+      Last   : Stream_Element_Offset;
+   begin
+      loop
+         Flush (Stream.Writer, Buffer, Last, Mode);
+
+         Ada.Streams.Write (Stream.Back.all, Buffer (1 .. Last));
+
+         exit when Last < Buffer'Last;
+      end loop;
+   end Flush;
+
+   -------------
+   -- Is_Open --
+   -------------
+
+   function Is_Open (Stream : Stream_Type) return Boolean is
+   begin
+      return Is_Open (Stream.Reader) or else Is_Open (Stream.Writer);
+   end Is_Open;
+
+   ----------
+   -- Read --
+   ----------
+
+   procedure Read
+     (Stream : in out Stream_Type;
+      Item   :    out Stream_Element_Array;
+      Last   :    out Stream_Element_Offset)
+   is
+
+      procedure Read
+        (Item : out Stream_Element_Array;
+         Last : out Stream_Element_Offset);
+
+      ----------
+      -- Read --
+      ----------
+
+      procedure Read
+        (Item : out Stream_Element_Array;
+         Last : out Stream_Element_Offset) is
+      begin
+         Ada.Streams.Read (Stream.Back.all, Item, Last);
+      end Read;
+
+      procedure Read is new ZLib.Read
+         (Read       => Read,
+          Buffer     => Stream.Buffer.all,
+          Rest_First => Stream.Rest_First,
+          Rest_Last  => Stream.Rest_Last);
+
+   begin
+      Read (Stream.Reader, Item, Last);
+   end Read;
+
+   -------------------
+   -- Read_Total_In --
+   -------------------
+
+   function Read_Total_In (Stream : in Stream_Type) return Count is
+   begin
+      return Total_In (Stream.Reader);
+   end Read_Total_In;
+
+   --------------------
+   -- Read_Total_Out --
+   --------------------
+
+   function Read_Total_Out (Stream : in Stream_Type) return Count is
+   begin
+      return Total_Out (Stream.Reader);
+   end Read_Total_Out;
+
+   -----------
+   -- Write --
+   -----------
+
+   procedure Write
+     (Stream : in out Stream_Type;
+      Item   : in     Stream_Element_Array)
+   is
+
+      procedure Write (Item : in Stream_Element_Array);
+
+      -----------
+      -- Write --
+      -----------
+
+      procedure Write (Item : in Stream_Element_Array) is
+      begin
+         Ada.Streams.Write (Stream.Back.all, Item);
+      end Write;
+
+      procedure Write is new ZLib.Write
+         (Write       => Write,
+          Buffer_Size => Stream.Buffer_Size);
+
+   begin
+      Write (Stream.Writer, Item, No_Flush);
+   end Write;
+
+   --------------------
+   -- Write_Total_In --
+   --------------------
+
+   function Write_Total_In (Stream : in Stream_Type) return Count is
+   begin
+      return Total_In (Stream.Writer);
+   end Write_Total_In;
+
+   ---------------------
+   -- Write_Total_Out --
+   ---------------------
+
+   function Write_Total_Out (Stream : in Stream_Type) return Count is
+   begin
+      return Total_Out (Stream.Writer);
+   end Write_Total_Out;
+
+end ZLib.Streams;
diff --git a/xs/src/png/zlib/contrib/ada/zlib-streams.ads b/xs/src/png/zlib/contrib/ada/zlib-streams.ads
new file mode 100644
index 000000000..8e26cd450
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib-streams.ads
@@ -0,0 +1,114 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-streams.ads,v 1.12 2004/05/31 10:53:40 vagul Exp $
+
+package ZLib.Streams is
+
+   type Stream_Mode is (In_Stream, Out_Stream, Duplex);
+
+   type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class;
+
+   type Stream_Type is
+      new Ada.Streams.Root_Stream_Type with private;
+
+   procedure Read
+     (Stream : in out Stream_Type;
+      Item   :    out Ada.Streams.Stream_Element_Array;
+      Last   :    out Ada.Streams.Stream_Element_Offset);
+
+   procedure Write
+     (Stream : in out Stream_Type;
+      Item   : in     Ada.Streams.Stream_Element_Array);
+
+   procedure Flush
+     (Stream : in out Stream_Type;
+      Mode   : in     Flush_Mode := Sync_Flush);
+   --  Flush the written data to the back stream,
+   --  all data placed to the compressor is flushing to the Back stream.
+   --  Should not be used until necessary, because it is decreasing
+   --  compression.
+
+   function Read_Total_In (Stream : in Stream_Type) return Count;
+   pragma Inline (Read_Total_In);
+   --  Return total number of bytes read from back stream so far.
+
+   function Read_Total_Out (Stream : in Stream_Type) return Count;
+   pragma Inline (Read_Total_Out);
+   --  Return total number of bytes read so far.
+
+   function Write_Total_In (Stream : in Stream_Type) return Count;
+   pragma Inline (Write_Total_In);
+   --  Return total number of bytes written so far.
+
+   function Write_Total_Out (Stream : in Stream_Type) return Count;
+   pragma Inline (Write_Total_Out);
+   --  Return total number of bytes written to the back stream.
+
+   procedure Create
+     (Stream            :    out Stream_Type;
+      Mode              : in     Stream_Mode;
+      Back              : in     Stream_Access;
+      Back_Compressed   : in     Boolean;
+      Level             : in     Compression_Level := Default_Compression;
+      Strategy          : in     Strategy_Type     := Default_Strategy;
+      Header            : in     Header_Type       := Default;
+      Read_Buffer_Size  : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size;
+      Write_Buffer_Size : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size);
+   --  Create the Comression/Decompression stream.
+   --  If mode is In_Stream then Write operation is disabled.
+   --  If mode is Out_Stream then Read operation is disabled.
+
+   --  If Back_Compressed is true then
+   --  Data written to the Stream is compressing to the Back stream
+   --  and data read from the Stream is decompressed data from the Back stream.
+
+   --  If Back_Compressed is false then
+   --  Data written to the Stream is decompressing to the Back stream
+   --  and data read from the Stream is compressed data from the Back stream.
+
+   --  !!! When the Need_Header is False ZLib-Ada is using undocumented
+   --  ZLib 1.1.4 functionality to do not create/wait for ZLib headers.
+
+   function Is_Open (Stream : Stream_Type) return Boolean;
+
+   procedure Close (Stream : in out Stream_Type);
+
+private
+
+   use Ada.Streams;
+
+   type Buffer_Access is access all Stream_Element_Array;
+
+   type Stream_Type
+     is new Root_Stream_Type with
+   record
+      Mode       : Stream_Mode;
+
+      Buffer     : Buffer_Access;
+      Rest_First : Stream_Element_Offset;
+      Rest_Last  : Stream_Element_Offset;
+      --  Buffer for Read operation.
+      --  We need to have this buffer in the record
+      --  because not all read data from back stream
+      --  could be processed during the read operation.
+
+      Buffer_Size : Stream_Element_Offset;
+      --  Buffer size for write operation.
+      --  We do not need to have this buffer
+      --  in the record because all data could be
+      --  processed in the write operation.
+
+      Back       : Stream_Access;
+      Reader     : Filter_Type;
+      Writer     : Filter_Type;
+   end record;
+
+end ZLib.Streams;
diff --git a/xs/src/png/zlib/contrib/ada/zlib-thin.adb b/xs/src/png/zlib/contrib/ada/zlib-thin.adb
new file mode 100644
index 000000000..0ca4a7120
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib-thin.adb
@@ -0,0 +1,141 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-thin.adb,v 1.8 2003/12/14 18:27:31 vagul Exp $
+
+package body ZLib.Thin is
+
+   ZLIB_VERSION  : constant Chars_Ptr := zlibVersion;
+
+   Z_Stream_Size : constant Int := Z_Stream'Size / System.Storage_Unit;
+
+   --------------
+   -- Avail_In --
+   --------------
+
+   function Avail_In (Strm : in Z_Stream) return UInt is
+   begin
+      return Strm.Avail_In;
+   end Avail_In;
+
+   ---------------
+   -- Avail_Out --
+   ---------------
+
+   function Avail_Out (Strm : in Z_Stream) return UInt is
+   begin
+      return Strm.Avail_Out;
+   end Avail_Out;
+
+   ------------------
+   -- Deflate_Init --
+   ------------------
+
+   function Deflate_Init
+     (strm       : Z_Streamp;
+      level      : Int;
+      method     : Int;
+      windowBits : Int;
+      memLevel   : Int;
+      strategy   : Int)
+      return       Int is
+   begin
+      return deflateInit2
+               (strm,
+                level,
+                method,
+                windowBits,
+                memLevel,
+                strategy,
+                ZLIB_VERSION,
+                Z_Stream_Size);
+   end Deflate_Init;
+
+   ------------------
+   -- Inflate_Init --
+   ------------------
+
+   function Inflate_Init (strm : Z_Streamp; windowBits : Int) return Int is
+   begin
+      return inflateInit2 (strm, windowBits, ZLIB_VERSION, Z_Stream_Size);
+   end Inflate_Init;
+
+   ------------------------
+   -- Last_Error_Message --
+   ------------------------
+
+   function Last_Error_Message (Strm : in Z_Stream) return String is
+      use Interfaces.C.Strings;
+   begin
+      if Strm.msg = Null_Ptr then
+         return "";
+      else
+         return Value (Strm.msg);
+      end if;
+   end Last_Error_Message;
+
+   ------------
+   -- Set_In --
+   ------------
+
+   procedure Set_In
+     (Strm   : in out Z_Stream;
+      Buffer : in     Voidp;
+      Size   : in     UInt) is
+   begin
+      Strm.Next_In  := Buffer;
+      Strm.Avail_In := Size;
+   end Set_In;
+
+   ------------------
+   -- Set_Mem_Func --
+   ------------------
+
+   procedure Set_Mem_Func
+     (Strm   : in out Z_Stream;
+      Opaque : in     Voidp;
+      Alloc  : in     alloc_func;
+      Free   : in     free_func) is
+   begin
+      Strm.opaque := Opaque;
+      Strm.zalloc := Alloc;
+      Strm.zfree  := Free;
+   end Set_Mem_Func;
+
+   -------------
+   -- Set_Out --
+   -------------
+
+   procedure Set_Out
+     (Strm   : in out Z_Stream;
+      Buffer : in     Voidp;
+      Size   : in     UInt) is
+   begin
+      Strm.Next_Out  := Buffer;
+      Strm.Avail_Out := Size;
+   end Set_Out;
+
+   --------------
+   -- Total_In --
+   --------------
+
+   function Total_In (Strm : in Z_Stream) return ULong is
+   begin
+      return Strm.Total_In;
+   end Total_In;
+
+   ---------------
+   -- Total_Out --
+   ---------------
+
+   function Total_Out (Strm : in Z_Stream) return ULong is
+   begin
+      return Strm.Total_Out;
+   end Total_Out;
+
+end ZLib.Thin;
diff --git a/xs/src/png/zlib/contrib/ada/zlib-thin.ads b/xs/src/png/zlib/contrib/ada/zlib-thin.ads
new file mode 100644
index 000000000..810173cff
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib-thin.ads
@@ -0,0 +1,450 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-thin.ads,v 1.11 2004/07/23 06:33:11 vagul Exp $
+
+with Interfaces.C.Strings;
+
+with System;
+
+private package ZLib.Thin is
+
+   --  From zconf.h
+
+   MAX_MEM_LEVEL : constant := 9;         --  zconf.h:105
+                                          --  zconf.h:105
+   MAX_WBITS : constant := 15;      --  zconf.h:115
+                                    --  32K LZ77 window
+                                    --  zconf.h:115
+   SEEK_SET : constant := 8#0000#;  --  zconf.h:244
+                                    --  Seek from beginning of file.
+                                    --  zconf.h:244
+   SEEK_CUR : constant := 1;        --  zconf.h:245
+                                    --  Seek from current position.
+                                    --  zconf.h:245
+   SEEK_END : constant := 2;        --  zconf.h:246
+                                    --  Set file pointer to EOF plus "offset"
+                                    --  zconf.h:246
+
+   type Byte is new Interfaces.C.unsigned_char; --  8 bits
+                                                --  zconf.h:214
+   type UInt is new Interfaces.C.unsigned;      --  16 bits or more
+                                                --  zconf.h:216
+   type Int is new Interfaces.C.int;
+
+   type ULong is new Interfaces.C.unsigned_long;     --  32 bits or more
+                                                     --  zconf.h:217
+   subtype Chars_Ptr is Interfaces.C.Strings.chars_ptr;
+
+   type ULong_Access is access ULong;
+   type Int_Access is access Int;
+
+   subtype Voidp is System.Address;            --  zconf.h:232
+
+   subtype Byte_Access is Voidp;
+
+   Nul : constant Voidp := System.Null_Address;
+   --  end from zconf
+
+   Z_NO_FLUSH : constant := 8#0000#;   --  zlib.h:125
+                                       --  zlib.h:125
+   Z_PARTIAL_FLUSH : constant := 1;       --  zlib.h:126
+                                          --  will be removed, use
+                                          --  Z_SYNC_FLUSH instead
+                                          --  zlib.h:126
+   Z_SYNC_FLUSH : constant := 2;       --  zlib.h:127
+                                       --  zlib.h:127
+   Z_FULL_FLUSH : constant := 3;       --  zlib.h:128
+                                       --  zlib.h:128
+   Z_FINISH : constant := 4;        --  zlib.h:129
+                                    --  zlib.h:129
+   Z_OK : constant := 8#0000#;   --  zlib.h:132
+                                 --  zlib.h:132
+   Z_STREAM_END : constant := 1;       --  zlib.h:133
+                                       --  zlib.h:133
+   Z_NEED_DICT : constant := 2;        --  zlib.h:134
+                                       --  zlib.h:134
+   Z_ERRNO : constant := -1;        --  zlib.h:135
+                                    --  zlib.h:135
+   Z_STREAM_ERROR : constant := -2;       --  zlib.h:136
+                                          --  zlib.h:136
+   Z_DATA_ERROR : constant := -3;      --  zlib.h:137
+                                       --  zlib.h:137
+   Z_MEM_ERROR : constant := -4;       --  zlib.h:138
+                                       --  zlib.h:138
+   Z_BUF_ERROR : constant := -5;       --  zlib.h:139
+                                       --  zlib.h:139
+   Z_VERSION_ERROR : constant := -6;      --  zlib.h:140
+                                          --  zlib.h:140
+   Z_NO_COMPRESSION : constant := 8#0000#;   --  zlib.h:145
+                                             --  zlib.h:145
+   Z_BEST_SPEED : constant := 1;       --  zlib.h:146
+                                       --  zlib.h:146
+   Z_BEST_COMPRESSION : constant := 9;       --  zlib.h:147
+                                             --  zlib.h:147
+   Z_DEFAULT_COMPRESSION : constant := -1;      --  zlib.h:148
+                                                --  zlib.h:148
+   Z_FILTERED : constant := 1;      --  zlib.h:151
+                                    --  zlib.h:151
+   Z_HUFFMAN_ONLY : constant := 2;        --  zlib.h:152
+                                          --  zlib.h:152
+   Z_DEFAULT_STRATEGY : constant := 8#0000#; --  zlib.h:153
+                                             --  zlib.h:153
+   Z_BINARY : constant := 8#0000#;  --  zlib.h:156
+                                    --  zlib.h:156
+   Z_ASCII : constant := 1;      --  zlib.h:157
+                                 --  zlib.h:157
+   Z_UNKNOWN : constant := 2;       --  zlib.h:158
+                                    --  zlib.h:158
+   Z_DEFLATED : constant := 8;      --  zlib.h:161
+                                    --  zlib.h:161
+   Z_NULL : constant := 8#0000#; --  zlib.h:164
+                                 --  for initializing zalloc, zfree, opaque
+                                 --  zlib.h:164
+   type gzFile is new Voidp;                  --  zlib.h:646
+
+   type Z_Stream is private;
+
+   type Z_Streamp is access all Z_Stream;     --  zlib.h:89
+
+   type alloc_func is access function
+     (Opaque : Voidp;
+      Items  : UInt;
+      Size   : UInt)
+      return Voidp; --  zlib.h:63
+
+   type free_func is access procedure (opaque : Voidp; address : Voidp);
+
+   function zlibVersion return Chars_Ptr;
+
+   function Deflate (strm : Z_Streamp; flush : Int) return Int;
+
+   function DeflateEnd (strm : Z_Streamp) return Int;
+
+   function Inflate (strm : Z_Streamp; flush : Int) return Int;
+
+   function InflateEnd (strm : Z_Streamp) return Int;
+
+   function deflateSetDictionary
+     (strm       : Z_Streamp;
+      dictionary : Byte_Access;
+      dictLength : UInt)
+      return       Int;
+
+   function deflateCopy (dest : Z_Streamp; source : Z_Streamp) return Int;
+   --  zlib.h:478
+
+   function deflateReset (strm : Z_Streamp) return Int; -- zlib.h:495
+
+   function deflateParams
+     (strm     : Z_Streamp;
+      level    : Int;
+      strategy : Int)
+      return     Int;       -- zlib.h:506
+
+   function inflateSetDictionary
+     (strm       : Z_Streamp;
+      dictionary : Byte_Access;
+      dictLength : UInt)
+      return       Int; --  zlib.h:548
+
+   function inflateSync (strm : Z_Streamp) return Int;  --  zlib.h:565
+
+   function inflateReset (strm : Z_Streamp) return Int; --  zlib.h:580
+
+   function compress
+     (dest      : Byte_Access;
+      destLen   : ULong_Access;
+      source    : Byte_Access;
+      sourceLen : ULong)
+      return      Int;           -- zlib.h:601
+
+   function compress2
+     (dest      : Byte_Access;
+      destLen   : ULong_Access;
+      source    : Byte_Access;
+      sourceLen : ULong;
+      level     : Int)
+      return      Int;          -- zlib.h:615
+
+   function uncompress
+     (dest      : Byte_Access;
+      destLen   : ULong_Access;
+      source    : Byte_Access;
+      sourceLen : ULong)
+      return      Int;
+
+   function gzopen (path : Chars_Ptr; mode : Chars_Ptr) return gzFile;
+
+   function gzdopen (fd : Int; mode : Chars_Ptr) return gzFile;
+
+   function gzsetparams
+     (file     : gzFile;
+      level    : Int;
+      strategy : Int)
+      return     Int;
+
+   function gzread
+     (file : gzFile;
+      buf  : Voidp;
+      len  : UInt)
+      return Int;
+
+   function gzwrite
+     (file : in gzFile;
+      buf  : in Voidp;
+      len  : in UInt)
+      return Int;
+
+   function gzprintf (file : in gzFile; format : in Chars_Ptr) return Int;
+
+   function gzputs (file : in gzFile; s : in Chars_Ptr) return Int;
+
+   function gzgets
+     (file : gzFile;
+      buf  : Chars_Ptr;
+      len  : Int)
+      return Chars_Ptr;
+
+   function gzputc (file : gzFile; char : Int) return Int;
+
+   function gzgetc (file : gzFile) return Int;
+
+   function gzflush (file : gzFile; flush : Int) return Int;
+
+   function gzseek
+     (file   : gzFile;
+      offset : Int;
+      whence : Int)
+      return   Int;
+
+   function gzrewind (file : gzFile) return Int;
+
+   function gztell (file : gzFile) return Int;
+
+   function gzeof (file : gzFile) return Int;
+
+   function gzclose (file : gzFile) return Int;
+
+   function gzerror (file : gzFile; errnum : Int_Access) return Chars_Ptr;
+
+   function adler32
+     (adler : ULong;
+      buf   : Byte_Access;
+      len   : UInt)
+      return  ULong;
+
+   function crc32
+     (crc  : ULong;
+      buf  : Byte_Access;
+      len  : UInt)
+      return ULong;
+
+   function deflateInit
+     (strm        : Z_Streamp;
+      level       : Int;
+      version     : Chars_Ptr;
+      stream_size : Int)
+      return        Int;
+
+   function deflateInit2
+     (strm        : Z_Streamp;
+      level       : Int;
+      method      : Int;
+      windowBits  : Int;
+      memLevel    : Int;
+      strategy    : Int;
+      version     : Chars_Ptr;
+      stream_size : Int)
+      return        Int;
+
+   function Deflate_Init
+     (strm       : Z_Streamp;
+      level      : Int;
+      method     : Int;
+      windowBits : Int;
+      memLevel   : Int;
+      strategy   : Int)
+      return       Int;
+   pragma Inline (Deflate_Init);
+
+   function inflateInit
+     (strm        : Z_Streamp;
+      version     : Chars_Ptr;
+      stream_size : Int)
+      return        Int;
+
+   function inflateInit2
+     (strm        : in Z_Streamp;
+      windowBits  : in Int;
+      version     : in Chars_Ptr;
+      stream_size : in Int)
+      return      Int;
+
+   function inflateBackInit
+     (strm        : in Z_Streamp;
+      windowBits  : in Int;
+      window      : in Byte_Access;
+      version     : in Chars_Ptr;
+      stream_size : in Int)
+      return      Int;
+   --  Size of window have to be 2**windowBits.
+
+   function Inflate_Init (strm : Z_Streamp; windowBits : Int) return Int;
+   pragma Inline (Inflate_Init);
+
+   function zError (err : Int) return Chars_Ptr;
+
+   function inflateSyncPoint (z : Z_Streamp) return Int;
+
+   function get_crc_table return ULong_Access;
+
+   --  Interface to the available fields of the z_stream structure.
+   --  The application must update next_in and avail_in when avail_in has
+   --  dropped to zero. It must update next_out and avail_out when avail_out
+   --  has dropped to zero. The application must initialize zalloc, zfree and
+   --  opaque before calling the init function.
+
+   procedure Set_In
+     (Strm   : in out Z_Stream;
+      Buffer : in Voidp;
+      Size   : in UInt);
+   pragma Inline (Set_In);
+
+   procedure Set_Out
+     (Strm   : in out Z_Stream;
+      Buffer : in Voidp;
+      Size   : in UInt);
+   pragma Inline (Set_Out);
+
+   procedure Set_Mem_Func
+     (Strm   : in out Z_Stream;
+      Opaque : in Voidp;
+      Alloc  : in alloc_func;
+      Free   : in free_func);
+   pragma Inline (Set_Mem_Func);
+
+   function Last_Error_Message (Strm : in Z_Stream) return String;
+   pragma Inline (Last_Error_Message);
+
+   function Avail_Out (Strm : in Z_Stream) return UInt;
+   pragma Inline (Avail_Out);
+
+   function Avail_In (Strm : in Z_Stream) return UInt;
+   pragma Inline (Avail_In);
+
+   function Total_In (Strm : in Z_Stream) return ULong;
+   pragma Inline (Total_In);
+
+   function Total_Out (Strm : in Z_Stream) return ULong;
+   pragma Inline (Total_Out);
+
+   function inflateCopy
+     (dest   : in Z_Streamp;
+      Source : in Z_Streamp)
+      return Int;
+
+   function compressBound (Source_Len : in ULong) return ULong;
+
+   function deflateBound
+     (Strm       : in Z_Streamp;
+      Source_Len : in ULong)
+      return     ULong;
+
+   function gzungetc (C : in Int; File : in  gzFile) return Int;
+
+   function zlibCompileFlags return ULong;
+
+private
+
+   type Z_Stream is record            -- zlib.h:68
+      Next_In   : Voidp      := Nul;  -- next input byte
+      Avail_In  : UInt       := 0;    -- number of bytes available at next_in
+      Total_In  : ULong      := 0;    -- total nb of input bytes read so far
+      Next_Out  : Voidp      := Nul;  -- next output byte should be put there
+      Avail_Out : UInt       := 0;    -- remaining free space at next_out
+      Total_Out : ULong      := 0;    -- total nb of bytes output so far
+      msg       : Chars_Ptr;          -- last error message, NULL if no error
+      state     : Voidp;              -- not visible by applications
+      zalloc    : alloc_func := null; -- used to allocate the internal state
+      zfree     : free_func  := null; -- used to free the internal state
+      opaque    : Voidp;              -- private data object passed to
+                                      --  zalloc and zfree
+      data_type : Int;                -- best guess about the data type:
+                                      --  ascii or binary
+      adler     : ULong;              -- adler32 value of the uncompressed
+                                      --  data
+      reserved  : ULong;              -- reserved for future use
+   end record;
+
+   pragma Convention (C, Z_Stream);
+
+   pragma Import (C, zlibVersion, "zlibVersion");
+   pragma Import (C, Deflate, "deflate");
+   pragma Import (C, DeflateEnd, "deflateEnd");
+   pragma Import (C, Inflate, "inflate");
+   pragma Import (C, InflateEnd, "inflateEnd");
+   pragma Import (C, deflateSetDictionary, "deflateSetDictionary");
+   pragma Import (C, deflateCopy, "deflateCopy");
+   pragma Import (C, deflateReset, "deflateReset");
+   pragma Import (C, deflateParams, "deflateParams");
+   pragma Import (C, inflateSetDictionary, "inflateSetDictionary");
+   pragma Import (C, inflateSync, "inflateSync");
+   pragma Import (C, inflateReset, "inflateReset");
+   pragma Import (C, compress, "compress");
+   pragma Import (C, compress2, "compress2");
+   pragma Import (C, uncompress, "uncompress");
+   pragma Import (C, gzopen, "gzopen");
+   pragma Import (C, gzdopen, "gzdopen");
+   pragma Import (C, gzsetparams, "gzsetparams");
+   pragma Import (C, gzread, "gzread");
+   pragma Import (C, gzwrite, "gzwrite");
+   pragma Import (C, gzprintf, "gzprintf");
+   pragma Import (C, gzputs, "gzputs");
+   pragma Import (C, gzgets, "gzgets");
+   pragma Import (C, gzputc, "gzputc");
+   pragma Import (C, gzgetc, "gzgetc");
+   pragma Import (C, gzflush, "gzflush");
+   pragma Import (C, gzseek, "gzseek");
+   pragma Import (C, gzrewind, "gzrewind");
+   pragma Import (C, gztell, "gztell");
+   pragma Import (C, gzeof, "gzeof");
+   pragma Import (C, gzclose, "gzclose");
+   pragma Import (C, gzerror, "gzerror");
+   pragma Import (C, adler32, "adler32");
+   pragma Import (C, crc32, "crc32");
+   pragma Import (C, deflateInit, "deflateInit_");
+   pragma Import (C, inflateInit, "inflateInit_");
+   pragma Import (C, deflateInit2, "deflateInit2_");
+   pragma Import (C, inflateInit2, "inflateInit2_");
+   pragma Import (C, zError, "zError");
+   pragma Import (C, inflateSyncPoint, "inflateSyncPoint");
+   pragma Import (C, get_crc_table, "get_crc_table");
+
+   --  since zlib 1.2.0:
+
+   pragma Import (C, inflateCopy, "inflateCopy");
+   pragma Import (C, compressBound, "compressBound");
+   pragma Import (C, deflateBound, "deflateBound");
+   pragma Import (C, gzungetc, "gzungetc");
+   pragma Import (C, zlibCompileFlags, "zlibCompileFlags");
+
+   pragma Import (C, inflateBackInit, "inflateBackInit_");
+
+   --  I stopped binding the inflateBack routines, because realize that
+   --  it does not support zlib and gzip headers for now, and have no
+   --  symmetric deflateBack routines.
+   --  ZLib-Ada is symmetric regarding deflate/inflate data transformation
+   --  and has a similar generic callback interface for the
+   --  deflate/inflate transformation based on the regular Deflate/Inflate
+   --  routines.
+
+   --  pragma Import (C, inflateBack, "inflateBack");
+   --  pragma Import (C, inflateBackEnd, "inflateBackEnd");
+
+end ZLib.Thin;
diff --git a/xs/src/png/zlib/contrib/ada/zlib.adb b/xs/src/png/zlib/contrib/ada/zlib.adb
new file mode 100644
index 000000000..8b6fd686a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib.adb
@@ -0,0 +1,701 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2004 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib.adb,v 1.31 2004/09/06 06:53:19 vagul Exp $
+
+with Ada.Exceptions;
+with Ada.Unchecked_Conversion;
+with Ada.Unchecked_Deallocation;
+
+with Interfaces.C.Strings;
+
+with ZLib.Thin;
+
+package body ZLib is
+
+   use type Thin.Int;
+
+   type Z_Stream is new Thin.Z_Stream;
+
+   type Return_Code_Enum is
+      (OK,
+       STREAM_END,
+       NEED_DICT,
+       ERRNO,
+       STREAM_ERROR,
+       DATA_ERROR,
+       MEM_ERROR,
+       BUF_ERROR,
+       VERSION_ERROR);
+
+   type Flate_Step_Function is access
+     function (Strm : in Thin.Z_Streamp; Flush : in Thin.Int) return Thin.Int;
+   pragma Convention (C, Flate_Step_Function);
+
+   type Flate_End_Function is access
+      function (Ctrm : in Thin.Z_Streamp) return Thin.Int;
+   pragma Convention (C, Flate_End_Function);
+
+   type Flate_Type is record
+      Step : Flate_Step_Function;
+      Done : Flate_End_Function;
+   end record;
+
+   subtype Footer_Array is Stream_Element_Array (1 .. 8);
+
+   Simple_GZip_Header : constant Stream_Element_Array (1 .. 10)
+     := (16#1f#, 16#8b#,                 --  Magic header
+         16#08#,                         --  Z_DEFLATED
+         16#00#,                         --  Flags
+         16#00#, 16#00#, 16#00#, 16#00#, --  Time
+         16#00#,                         --  XFlags
+         16#03#                          --  OS code
+        );
+   --  The simplest gzip header is not for informational, but just for
+   --  gzip format compatibility.
+   --  Note that some code below is using assumption
+   --  Simple_GZip_Header'Last > Footer_Array'Last, so do not make
+   --  Simple_GZip_Header'Last <= Footer_Array'Last.
+
+   Return_Code : constant array (Thin.Int range <>) of Return_Code_Enum
+     := (0 => OK,
+         1 => STREAM_END,
+         2 => NEED_DICT,
+        -1 => ERRNO,
+        -2 => STREAM_ERROR,
+        -3 => DATA_ERROR,
+        -4 => MEM_ERROR,
+        -5 => BUF_ERROR,
+        -6 => VERSION_ERROR);
+
+   Flate : constant array (Boolean) of Flate_Type
+     := (True  => (Step => Thin.Deflate'Access,
+                   Done => Thin.DeflateEnd'Access),
+         False => (Step => Thin.Inflate'Access,
+                   Done => Thin.InflateEnd'Access));
+
+   Flush_Finish : constant array (Boolean) of Flush_Mode
+     := (True => Finish, False => No_Flush);
+
+   procedure Raise_Error (Stream : in Z_Stream);
+   pragma Inline (Raise_Error);
+
+   procedure Raise_Error (Message : in String);
+   pragma Inline (Raise_Error);
+
+   procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int);
+
+   procedure Free is new Ada.Unchecked_Deallocation
+      (Z_Stream, Z_Stream_Access);
+
+   function To_Thin_Access is new Ada.Unchecked_Conversion
+     (Z_Stream_Access, Thin.Z_Streamp);
+
+   procedure Translate_GZip
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   --  Separate translate routine for make gzip header.
+
+   procedure Translate_Auto
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   --  translate routine without additional headers.
+
+   -----------------
+   -- Check_Error --
+   -----------------
+
+   procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int) is
+      use type Thin.Int;
+   begin
+      if Code /= Thin.Z_OK then
+         Raise_Error
+            (Return_Code_Enum'Image (Return_Code (Code))
+              & ": " & Last_Error_Message (Stream));
+      end if;
+   end Check_Error;
+
+   -----------
+   -- Close --
+   -----------
+
+   procedure Close
+     (Filter       : in out Filter_Type;
+      Ignore_Error : in     Boolean := False)
+   is
+      Code : Thin.Int;
+   begin
+      if not Ignore_Error and then not Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      Code := Flate (Filter.Compression).Done (To_Thin_Access (Filter.Strm));
+
+      if Ignore_Error or else Code = Thin.Z_OK then
+         Free (Filter.Strm);
+      else
+         declare
+            Error_Message : constant String
+              := Last_Error_Message (Filter.Strm.all);
+         begin
+            Free (Filter.Strm);
+            Ada.Exceptions.Raise_Exception
+               (ZLib_Error'Identity,
+                Return_Code_Enum'Image (Return_Code (Code))
+                  & ": " & Error_Message);
+         end;
+      end if;
+   end Close;
+
+   -----------
+   -- CRC32 --
+   -----------
+
+   function CRC32
+     (CRC  : in Unsigned_32;
+      Data : in Ada.Streams.Stream_Element_Array)
+      return Unsigned_32
+   is
+      use Thin;
+   begin
+      return Unsigned_32 (crc32 (ULong (CRC),
+                                 Data'Address,
+                                 Data'Length));
+   end CRC32;
+
+   procedure CRC32
+     (CRC  : in out Unsigned_32;
+      Data : in     Ada.Streams.Stream_Element_Array) is
+   begin
+      CRC := CRC32 (CRC, Data);
+   end CRC32;
+
+   ------------------
+   -- Deflate_Init --
+   ------------------
+
+   procedure Deflate_Init
+     (Filter       : in out Filter_Type;
+      Level        : in     Compression_Level  := Default_Compression;
+      Strategy     : in     Strategy_Type      := Default_Strategy;
+      Method       : in     Compression_Method := Deflated;
+      Window_Bits  : in     Window_Bits_Type   := Default_Window_Bits;
+      Memory_Level : in     Memory_Level_Type  := Default_Memory_Level;
+      Header       : in     Header_Type        := Default)
+   is
+      use type Thin.Int;
+      Win_Bits : Thin.Int := Thin.Int (Window_Bits);
+   begin
+      if Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      --  We allow ZLib to make header only in case of default header type.
+      --  Otherwise we would either do header by ourselfs, or do not do
+      --  header at all.
+
+      if Header = None or else Header = GZip then
+         Win_Bits := -Win_Bits;
+      end if;
+
+      --  For the GZip CRC calculation and make headers.
+
+      if Header = GZip then
+         Filter.CRC    := 0;
+         Filter.Offset := Simple_GZip_Header'First;
+      else
+         Filter.Offset := Simple_GZip_Header'Last + 1;
+      end if;
+
+      Filter.Strm        := new Z_Stream;
+      Filter.Compression := True;
+      Filter.Stream_End  := False;
+      Filter.Header      := Header;
+
+      if Thin.Deflate_Init
+           (To_Thin_Access (Filter.Strm),
+            Level      => Thin.Int (Level),
+            method     => Thin.Int (Method),
+            windowBits => Win_Bits,
+            memLevel   => Thin.Int (Memory_Level),
+            strategy   => Thin.Int (Strategy)) /= Thin.Z_OK
+      then
+         Raise_Error (Filter.Strm.all);
+      end if;
+   end Deflate_Init;
+
+   -----------
+   -- Flush --
+   -----------
+
+   procedure Flush
+     (Filter    : in out Filter_Type;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode)
+   is
+      No_Data : Stream_Element_Array := (1 .. 0 => 0);
+      Last    : Stream_Element_Offset;
+   begin
+      Translate (Filter, No_Data, Last, Out_Data, Out_Last, Flush);
+   end Flush;
+
+   -----------------------
+   -- Generic_Translate --
+   -----------------------
+
+   procedure Generic_Translate
+     (Filter          : in out ZLib.Filter_Type;
+      In_Buffer_Size  : in     Integer := Default_Buffer_Size;
+      Out_Buffer_Size : in     Integer := Default_Buffer_Size)
+   is
+      In_Buffer  : Stream_Element_Array
+                     (1 .. Stream_Element_Offset (In_Buffer_Size));
+      Out_Buffer : Stream_Element_Array
+                     (1 .. Stream_Element_Offset (Out_Buffer_Size));
+      Last       : Stream_Element_Offset;
+      In_Last    : Stream_Element_Offset;
+      In_First   : Stream_Element_Offset;
+      Out_Last   : Stream_Element_Offset;
+   begin
+      Main : loop
+         Data_In (In_Buffer, Last);
+
+         In_First := In_Buffer'First;
+
+         loop
+            Translate
+              (Filter   => Filter,
+               In_Data  => In_Buffer (In_First .. Last),
+               In_Last  => In_Last,
+               Out_Data => Out_Buffer,
+               Out_Last => Out_Last,
+               Flush    => Flush_Finish (Last < In_Buffer'First));
+
+            if Out_Buffer'First <= Out_Last then
+               Data_Out (Out_Buffer (Out_Buffer'First .. Out_Last));
+            end if;
+
+            exit Main when Stream_End (Filter);
+
+            --  The end of in buffer.
+
+            exit when In_Last = Last;
+
+            In_First := In_Last + 1;
+         end loop;
+      end loop Main;
+
+   end Generic_Translate;
+
+   ------------------
+   -- Inflate_Init --
+   ------------------
+
+   procedure Inflate_Init
+     (Filter      : in out Filter_Type;
+      Window_Bits : in     Window_Bits_Type := Default_Window_Bits;
+      Header      : in     Header_Type      := Default)
+   is
+      use type Thin.Int;
+      Win_Bits : Thin.Int := Thin.Int (Window_Bits);
+
+      procedure Check_Version;
+      --  Check the latest header types compatibility.
+
+      procedure Check_Version is
+      begin
+         if Version <= "1.1.4" then
+            Raise_Error
+              ("Inflate header type " & Header_Type'Image (Header)
+               & " incompatible with ZLib version " & Version);
+         end if;
+      end Check_Version;
+
+   begin
+      if Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      case Header is
+         when None =>
+            Check_Version;
+
+            --  Inflate data without headers determined
+            --  by negative Win_Bits.
+
+            Win_Bits := -Win_Bits;
+         when GZip =>
+            Check_Version;
+
+            --  Inflate gzip data defined by flag 16.
+
+            Win_Bits := Win_Bits + 16;
+         when Auto =>
+            Check_Version;
+
+            --  Inflate with automatic detection
+            --  of gzip or native header defined by flag 32.
+
+            Win_Bits := Win_Bits + 32;
+         when Default => null;
+      end case;
+
+      Filter.Strm        := new Z_Stream;
+      Filter.Compression := False;
+      Filter.Stream_End  := False;
+      Filter.Header      := Header;
+
+      if Thin.Inflate_Init
+         (To_Thin_Access (Filter.Strm), Win_Bits) /= Thin.Z_OK
+      then
+         Raise_Error (Filter.Strm.all);
+      end if;
+   end Inflate_Init;
+
+   -------------
+   -- Is_Open --
+   -------------
+
+   function Is_Open (Filter : in Filter_Type) return Boolean is
+   begin
+      return Filter.Strm /= null;
+   end Is_Open;
+
+   -----------------
+   -- Raise_Error --
+   -----------------
+
+   procedure Raise_Error (Message : in String) is
+   begin
+      Ada.Exceptions.Raise_Exception (ZLib_Error'Identity, Message);
+   end Raise_Error;
+
+   procedure Raise_Error (Stream : in Z_Stream) is
+   begin
+      Raise_Error (Last_Error_Message (Stream));
+   end Raise_Error;
+
+   ----------
+   -- Read --
+   ----------
+
+   procedure Read
+     (Filter : in out Filter_Type;
+      Item   :    out Ada.Streams.Stream_Element_Array;
+      Last   :    out Ada.Streams.Stream_Element_Offset;
+      Flush  : in     Flush_Mode := No_Flush)
+   is
+      In_Last    : Stream_Element_Offset;
+      Item_First : Ada.Streams.Stream_Element_Offset := Item'First;
+      V_Flush    : Flush_Mode := Flush;
+
+   begin
+      pragma Assert (Rest_First in Buffer'First .. Buffer'Last + 1);
+      pragma Assert (Rest_Last in Buffer'First - 1 .. Buffer'Last);
+
+      loop
+         if Rest_Last = Buffer'First - 1 then
+            V_Flush := Finish;
+
+         elsif Rest_First > Rest_Last then
+            Read (Buffer, Rest_Last);
+            Rest_First := Buffer'First;
+
+            if Rest_Last < Buffer'First then
+               V_Flush := Finish;
+            end if;
+         end if;
+
+         Translate
+           (Filter   => Filter,
+            In_Data  => Buffer (Rest_First .. Rest_Last),
+            In_Last  => In_Last,
+            Out_Data => Item (Item_First .. Item'Last),
+            Out_Last => Last,
+            Flush    => V_Flush);
+
+         Rest_First := In_Last + 1;
+
+         exit when Stream_End (Filter)
+           or else Last = Item'Last
+           or else (Last >= Item'First and then Allow_Read_Some);
+
+         Item_First := Last + 1;
+      end loop;
+   end Read;
+
+   ----------------
+   -- Stream_End --
+   ----------------
+
+   function Stream_End (Filter : in Filter_Type) return Boolean is
+   begin
+      if Filter.Header = GZip and Filter.Compression then
+         return Filter.Stream_End
+            and then Filter.Offset = Footer_Array'Last + 1;
+      else
+         return Filter.Stream_End;
+      end if;
+   end Stream_End;
+
+   --------------
+   -- Total_In --
+   --------------
+
+   function Total_In (Filter : in Filter_Type) return Count is
+   begin
+      return Count (Thin.Total_In (To_Thin_Access (Filter.Strm).all));
+   end Total_In;
+
+   ---------------
+   -- Total_Out --
+   ---------------
+
+   function Total_Out (Filter : in Filter_Type) return Count is
+   begin
+      return Count (Thin.Total_Out (To_Thin_Access (Filter.Strm).all));
+   end Total_Out;
+
+   ---------------
+   -- Translate --
+   ---------------
+
+   procedure Translate
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode) is
+   begin
+      if Filter.Header = GZip and then Filter.Compression then
+         Translate_GZip
+           (Filter   => Filter,
+            In_Data  => In_Data,
+            In_Last  => In_Last,
+            Out_Data => Out_Data,
+            Out_Last => Out_Last,
+            Flush    => Flush);
+      else
+         Translate_Auto
+           (Filter   => Filter,
+            In_Data  => In_Data,
+            In_Last  => In_Last,
+            Out_Data => Out_Data,
+            Out_Last => Out_Last,
+            Flush    => Flush);
+      end if;
+   end Translate;
+
+   --------------------
+   -- Translate_Auto --
+   --------------------
+
+   procedure Translate_Auto
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode)
+   is
+      use type Thin.Int;
+      Code : Thin.Int;
+
+   begin
+      if not Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      if Out_Data'Length = 0 and then In_Data'Length = 0 then
+         raise Constraint_Error;
+      end if;
+
+      Set_Out (Filter.Strm.all, Out_Data'Address, Out_Data'Length);
+      Set_In  (Filter.Strm.all, In_Data'Address, In_Data'Length);
+
+      Code := Flate (Filter.Compression).Step
+        (To_Thin_Access (Filter.Strm),
+         Thin.Int (Flush));
+
+      if Code = Thin.Z_STREAM_END then
+         Filter.Stream_End := True;
+      else
+         Check_Error (Filter.Strm.all, Code);
+      end if;
+
+      In_Last  := In_Data'Last
+         - Stream_Element_Offset (Avail_In (Filter.Strm.all));
+      Out_Last := Out_Data'Last
+         - Stream_Element_Offset (Avail_Out (Filter.Strm.all));
+   end Translate_Auto;
+
+   --------------------
+   -- Translate_GZip --
+   --------------------
+
+   procedure Translate_GZip
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode)
+   is
+      Out_First : Stream_Element_Offset;
+
+      procedure Add_Data (Data : in Stream_Element_Array);
+      --  Add data to stream from the Filter.Offset till necessary,
+      --  used for add gzip headr/footer.
+
+      procedure Put_32
+        (Item : in out Stream_Element_Array;
+         Data : in     Unsigned_32);
+      pragma Inline (Put_32);
+
+      --------------
+      -- Add_Data --
+      --------------
+
+      procedure Add_Data (Data : in Stream_Element_Array) is
+         Data_First : Stream_Element_Offset renames Filter.Offset;
+         Data_Last  : Stream_Element_Offset;
+         Data_Len   : Stream_Element_Offset; --  -1
+         Out_Len    : Stream_Element_Offset; --  -1
+      begin
+         Out_First := Out_Last + 1;
+
+         if Data_First > Data'Last then
+            return;
+         end if;
+
+         Data_Len  := Data'Last     - Data_First;
+         Out_Len   := Out_Data'Last - Out_First;
+
+         if Data_Len <= Out_Len then
+            Out_Last  := Out_First  + Data_Len;
+            Data_Last := Data'Last;
+         else
+            Out_Last  := Out_Data'Last;
+            Data_Last := Data_First + Out_Len;
+         end if;
+
+         Out_Data (Out_First .. Out_Last) := Data (Data_First .. Data_Last);
+
+         Data_First := Data_Last + 1;
+         Out_First  := Out_Last + 1;
+      end Add_Data;
+
+      ------------
+      -- Put_32 --
+      ------------
+
+      procedure Put_32
+        (Item : in out Stream_Element_Array;
+         Data : in     Unsigned_32)
+      is
+         D : Unsigned_32 := Data;
+      begin
+         for J in Item'First .. Item'First + 3 loop
+            Item (J) := Stream_Element (D and 16#FF#);
+            D := Shift_Right (D, 8);
+         end loop;
+      end Put_32;
+
+   begin
+      Out_Last := Out_Data'First - 1;
+
+      if not Filter.Stream_End then
+         Add_Data (Simple_GZip_Header);
+
+         Translate_Auto
+           (Filter   => Filter,
+            In_Data  => In_Data,
+            In_Last  => In_Last,
+            Out_Data => Out_Data (Out_First .. Out_Data'Last),
+            Out_Last => Out_Last,
+            Flush    => Flush);
+
+         CRC32 (Filter.CRC, In_Data (In_Data'First .. In_Last));
+      end if;
+
+      if Filter.Stream_End and then Out_Last <= Out_Data'Last then
+         --  This detection method would work only when
+         --  Simple_GZip_Header'Last > Footer_Array'Last
+
+         if Filter.Offset = Simple_GZip_Header'Last + 1 then
+            Filter.Offset := Footer_Array'First;
+         end if;
+
+         declare
+            Footer : Footer_Array;
+         begin
+            Put_32 (Footer, Filter.CRC);
+            Put_32 (Footer (Footer'First + 4 .. Footer'Last),
+                    Unsigned_32 (Total_In (Filter)));
+            Add_Data (Footer);
+         end;
+      end if;
+   end Translate_GZip;
+
+   -------------
+   -- Version --
+   -------------
+
+   function Version return String is
+   begin
+      return Interfaces.C.Strings.Value (Thin.zlibVersion);
+   end Version;
+
+   -----------
+   -- Write --
+   -----------
+
+   procedure Write
+     (Filter : in out Filter_Type;
+      Item   : in     Ada.Streams.Stream_Element_Array;
+      Flush  : in     Flush_Mode := No_Flush)
+   is
+      Buffer   : Stream_Element_Array (1 .. Buffer_Size);
+      In_Last  : Stream_Element_Offset;
+      Out_Last : Stream_Element_Offset;
+      In_First : Stream_Element_Offset := Item'First;
+   begin
+      if Item'Length = 0 and Flush = No_Flush then
+         return;
+      end if;
+
+      loop
+         Translate
+           (Filter   => Filter,
+            In_Data  => Item (In_First .. Item'Last),
+            In_Last  => In_Last,
+            Out_Data => Buffer,
+            Out_Last => Out_Last,
+            Flush    => Flush);
+
+         if Out_Last >= Buffer'First then
+            Write (Buffer (1 .. Out_Last));
+         end if;
+
+         exit when In_Last = Item'Last or Stream_End (Filter);
+
+         In_First := In_Last + 1;
+      end loop;
+   end Write;
+
+end ZLib;
diff --git a/xs/src/png/zlib/contrib/ada/zlib.ads b/xs/src/png/zlib/contrib/ada/zlib.ads
new file mode 100644
index 000000000..79ffc4095
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib.ads
@@ -0,0 +1,328 @@
+------------------------------------------------------------------------------
+--                      ZLib for Ada thick binding.                         --
+--                                                                          --
+--              Copyright (C) 2002-2004 Dmitriy Anisimkov                   --
+--                                                                          --
+--  This library is free software; you can redistribute it and/or modify    --
+--  it under the terms of the GNU General Public License as published by    --
+--  the Free Software Foundation; either version 2 of the License, or (at   --
+--  your option) any later version.                                         --
+--                                                                          --
+--  This library is distributed in the hope that it will be useful, but     --
+--  WITHOUT ANY WARRANTY; without even the implied warranty of              --
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU       --
+--  General Public License for more details.                                --
+--                                                                          --
+--  You should have received a copy of the GNU General Public License       --
+--  along with this library; if not, write to the Free Software Foundation, --
+--  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.          --
+--                                                                          --
+--  As a special exception, if other files instantiate generics from this   --
+--  unit, or you link this unit with other files to produce an executable,  --
+--  this  unit  does not  by itself cause  the resulting executable to be   --
+--  covered by the GNU General Public License. This exception does not      --
+--  however invalidate any other reasons why the executable file  might be  --
+--  covered by the  GNU Public License.                                     --
+------------------------------------------------------------------------------
+
+--  $Id: zlib.ads,v 1.26 2004/09/06 06:53:19 vagul Exp $
+
+with Ada.Streams;
+
+with Interfaces;
+
+package ZLib is
+
+   ZLib_Error   : exception;
+   Status_Error : exception;
+
+   type Compression_Level is new Integer range -1 .. 9;
+
+   type Flush_Mode is private;
+
+   type Compression_Method is private;
+
+   type Window_Bits_Type is new Integer range 8 .. 15;
+
+   type Memory_Level_Type is new Integer range 1 .. 9;
+
+   type Unsigned_32 is new Interfaces.Unsigned_32;
+
+   type Strategy_Type is private;
+
+   type Header_Type is (None, Auto, Default, GZip);
+   --  Header type usage have a some limitation for inflate.
+   --  See comment for Inflate_Init.
+
+   subtype Count is Ada.Streams.Stream_Element_Count;
+
+   Default_Memory_Level : constant Memory_Level_Type := 8;
+   Default_Window_Bits  : constant Window_Bits_Type  := 15;
+
+   ----------------------------------
+   -- Compression method constants --
+   ----------------------------------
+
+   Deflated : constant Compression_Method;
+   --  Only one method allowed in this ZLib version
+
+   ---------------------------------
+   -- Compression level constants --
+   ---------------------------------
+
+   No_Compression      : constant Compression_Level := 0;
+   Best_Speed          : constant Compression_Level := 1;
+   Best_Compression    : constant Compression_Level := 9;
+   Default_Compression : constant Compression_Level := -1;
+
+   --------------------------
+   -- Flush mode constants --
+   --------------------------
+
+   No_Flush      : constant Flush_Mode;
+   --  Regular way for compression, no flush
+
+   Partial_Flush : constant Flush_Mode;
+   --  Will be removed, use Z_SYNC_FLUSH instead
+
+   Sync_Flush    : constant Flush_Mode;
+   --  All pending output is flushed to the output buffer and the output
+   --  is aligned on a byte boundary, so that the decompressor can get all
+   --  input data available so far. (In particular avail_in is zero after the
+   --  call if enough output space has been provided  before the call.)
+   --  Flushing may degrade compression for some compression algorithms and so
+   --  it should be used only when necessary.
+
+   Block_Flush   : constant Flush_Mode;
+   --  Z_BLOCK requests that inflate() stop
+   --  if and when it get to the next deflate block boundary. When decoding the
+   --  zlib or gzip format, this will cause inflate() to return immediately
+   --  after the header and before the first block. When doing a raw inflate,
+   --  inflate() will go ahead and process the first block, and will return
+   --  when it gets to the end of that block, or when it runs out of data.
+
+   Full_Flush    : constant Flush_Mode;
+   --  All output is flushed as with SYNC_FLUSH, and the compression state
+   --  is reset so that decompression can restart from this point if previous
+   --  compressed data has been damaged or if random access is desired. Using
+   --  Full_Flush too often can seriously degrade the compression.
+
+   Finish        : constant Flush_Mode;
+   --  Just for tell the compressor that input data is complete.
+
+   ------------------------------------
+   -- Compression strategy constants --
+   ------------------------------------
+
+   --  RLE stategy could be used only in version 1.2.0 and later.
+
+   Filtered         : constant Strategy_Type;
+   Huffman_Only     : constant Strategy_Type;
+   RLE              : constant Strategy_Type;
+   Default_Strategy : constant Strategy_Type;
+
+   Default_Buffer_Size : constant := 4096;
+
+   type Filter_Type is tagged limited private;
+   --  The filter is for compression and for decompression.
+   --  The usage of the type is depend of its initialization.
+
+   function Version return String;
+   pragma Inline (Version);
+   --  Return string representation of the ZLib version.
+
+   procedure Deflate_Init
+     (Filter       : in out Filter_Type;
+      Level        : in     Compression_Level  := Default_Compression;
+      Strategy     : in     Strategy_Type      := Default_Strategy;
+      Method       : in     Compression_Method := Deflated;
+      Window_Bits  : in     Window_Bits_Type   := Default_Window_Bits;
+      Memory_Level : in     Memory_Level_Type  := Default_Memory_Level;
+      Header       : in     Header_Type        := Default);
+   --  Compressor initialization.
+   --  When Header parameter is Auto or Default, then default zlib header
+   --  would be provided for compressed data.
+   --  When Header is GZip, then gzip header would be set instead of
+   --  default header.
+   --  When Header is None, no header would be set for compressed data.
+
+   procedure Inflate_Init
+     (Filter      : in out Filter_Type;
+      Window_Bits : in     Window_Bits_Type := Default_Window_Bits;
+      Header      : in     Header_Type      := Default);
+   --  Decompressor initialization.
+   --  Default header type mean that ZLib default header is expecting in the
+   --  input compressed stream.
+   --  Header type None mean that no header is expecting in the input stream.
+   --  GZip header type mean that GZip header is expecting in the
+   --  input compressed stream.
+   --  Auto header type mean that header type (GZip or Native) would be
+   --  detected automatically in the input stream.
+   --  Note that header types parameter values None, GZip and Auto are
+   --  supported for inflate routine only in ZLib versions 1.2.0.2 and later.
+   --  Deflate_Init is supporting all header types.
+
+   function Is_Open (Filter : in Filter_Type) return Boolean;
+   pragma Inline (Is_Open);
+   --  Is the filter opened for compression or decompression.
+
+   procedure Close
+     (Filter       : in out Filter_Type;
+      Ignore_Error : in     Boolean := False);
+   --  Closing the compression or decompressor.
+   --  If stream is closing before the complete and Ignore_Error is False,
+   --  The exception would be raised.
+
+   generic
+      with procedure Data_In
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset);
+      with procedure Data_Out
+        (Item : in Ada.Streams.Stream_Element_Array);
+   procedure Generic_Translate
+     (Filter          : in out Filter_Type;
+      In_Buffer_Size  : in     Integer := Default_Buffer_Size;
+      Out_Buffer_Size : in     Integer := Default_Buffer_Size);
+   --  Compress/decompress data fetch from Data_In routine and pass the result
+   --  to the Data_Out routine. User should provide Data_In and Data_Out
+   --  for compression/decompression data flow.
+   --  Compression or decompression depend on Filter initialization.
+
+   function Total_In (Filter : in Filter_Type) return Count;
+   pragma Inline (Total_In);
+   --  Returns total number of input bytes read so far
+
+   function Total_Out (Filter : in Filter_Type) return Count;
+   pragma Inline (Total_Out);
+   --  Returns total number of bytes output so far
+
+   function CRC32
+     (CRC    : in Unsigned_32;
+      Data   : in Ada.Streams.Stream_Element_Array)
+      return Unsigned_32;
+   pragma Inline (CRC32);
+   --  Compute CRC32, it could be necessary for make gzip format
+
+   procedure CRC32
+     (CRC  : in out Unsigned_32;
+      Data : in     Ada.Streams.Stream_Element_Array);
+   pragma Inline (CRC32);
+   --  Compute CRC32, it could be necessary for make gzip format
+
+   -------------------------------------------------
+   --  Below is more complex low level routines.  --
+   -------------------------------------------------
+
+   procedure Translate
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   --  Compress/decompress the In_Data buffer and place the result into
+   --  Out_Data. In_Last is the index of last element from In_Data accepted by
+   --  the Filter. Out_Last is the last element of the received data from
+   --  Filter. To tell the filter that incoming data are complete put the
+   --  Flush parameter to Finish.
+
+   function Stream_End (Filter : in Filter_Type) return Boolean;
+   pragma Inline (Stream_End);
+   --  Return the true when the stream is complete.
+
+   procedure Flush
+     (Filter    : in out Filter_Type;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   pragma Inline (Flush);
+   --  Flushing the data from the compressor.
+
+   generic
+      with procedure Write
+        (Item : in Ada.Streams.Stream_Element_Array);
+      --  User should provide this routine for accept
+      --  compressed/decompressed data.
+
+      Buffer_Size : in Ada.Streams.Stream_Element_Offset
+         := Default_Buffer_Size;
+      --  Buffer size for Write user routine.
+
+   procedure Write
+     (Filter  : in out Filter_Type;
+      Item    : in     Ada.Streams.Stream_Element_Array;
+      Flush   : in     Flush_Mode := No_Flush);
+   --  Compress/Decompress data from Item to the generic parameter procedure
+   --  Write. Output buffer size could be set in Buffer_Size generic parameter.
+
+   generic
+      with procedure Read
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset);
+      --  User should provide data for compression/decompression
+      --  thru this routine.
+
+      Buffer : in out Ada.Streams.Stream_Element_Array;
+      --  Buffer for keep remaining data from the previous
+      --  back read.
+
+      Rest_First, Rest_Last : in out Ada.Streams.Stream_Element_Offset;
+      --  Rest_First have to be initialized to Buffer'Last + 1
+      --  Rest_Last have to be initialized to Buffer'Last
+      --  before usage.
+
+      Allow_Read_Some : in Boolean := False;
+      --  Is it allowed to return Last < Item'Last before end of data.
+
+   procedure Read
+     (Filter : in out Filter_Type;
+      Item   :    out Ada.Streams.Stream_Element_Array;
+      Last   :    out Ada.Streams.Stream_Element_Offset;
+      Flush  : in     Flush_Mode := No_Flush);
+   --  Compress/Decompress data from generic parameter procedure Read to the
+   --  Item. User should provide Buffer and initialized Rest_First, Rest_Last
+   --  indicators. If Allow_Read_Some is True, Read routines could return
+   --  Last < Item'Last only at end of stream.
+
+private
+
+   use Ada.Streams;
+
+   pragma Assert (Ada.Streams.Stream_Element'Size    =    8);
+   pragma Assert (Ada.Streams.Stream_Element'Modulus = 2**8);
+
+   type Flush_Mode is new Integer range 0 .. 5;
+
+   type Compression_Method is new Integer range 8 .. 8;
+
+   type Strategy_Type is new Integer range 0 .. 3;
+
+   No_Flush      : constant Flush_Mode := 0;
+   Partial_Flush : constant Flush_Mode := 1;
+   Sync_Flush    : constant Flush_Mode := 2;
+   Full_Flush    : constant Flush_Mode := 3;
+   Finish        : constant Flush_Mode := 4;
+   Block_Flush   : constant Flush_Mode := 5;
+
+   Filtered         : constant Strategy_Type := 1;
+   Huffman_Only     : constant Strategy_Type := 2;
+   RLE              : constant Strategy_Type := 3;
+   Default_Strategy : constant Strategy_Type := 0;
+
+   Deflated : constant Compression_Method := 8;
+
+   type Z_Stream;
+
+   type Z_Stream_Access is access all Z_Stream;
+
+   type Filter_Type is tagged limited record
+      Strm        : Z_Stream_Access;
+      Compression : Boolean;
+      Stream_End  : Boolean;
+      Header      : Header_Type;
+      CRC         : Unsigned_32;
+      Offset      : Stream_Element_Offset;
+      --  Offset for gzip header/footer output.
+   end record;
+
+end ZLib;
diff --git a/xs/src/png/zlib/contrib/ada/zlib.gpr b/xs/src/png/zlib/contrib/ada/zlib.gpr
new file mode 100644
index 000000000..296b22aa9
--- /dev/null
+++ b/xs/src/png/zlib/contrib/ada/zlib.gpr
@@ -0,0 +1,20 @@
+project Zlib is
+
+   for Languages use ("Ada");
+   for Source_Dirs use (".");
+   for Object_Dir use ".";
+   for Main use ("test.adb", "mtest.adb", "read.adb", "buffer_demo");
+
+   package Compiler is
+      for Default_Switches ("ada") use ("-gnatwcfilopru", "-gnatVcdfimorst", "-gnatyabcefhiklmnoprst");
+   end Compiler;
+
+   package Linker is
+      for Default_Switches ("ada") use ("-lz");
+   end Linker;
+
+   package Builder is
+      for Default_Switches ("ada") use ("-s", "-gnatQ");
+   end Builder;
+
+end Zlib;
diff --git a/xs/src/png/zlib/contrib/amd64/amd64-match.S b/xs/src/png/zlib/contrib/amd64/amd64-match.S
new file mode 100644
index 000000000..81d4a1c94
--- /dev/null
+++ b/xs/src/png/zlib/contrib/amd64/amd64-match.S
@@ -0,0 +1,452 @@
+/*
+ * match.S -- optimized version of longest_match()
+ * based on the similar work by Gilles Vollant, and Brian Raiter, written 1998
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the BSD License. Use by owners of Che Guevarra
+ * parafernalia is prohibited, where possible, and highly discouraged
+ * elsewhere.
+ */
+
+#ifndef NO_UNDERLINE
+#	define	match_init	_match_init
+#	define	longest_match	_longest_match
+#endif
+
+#define	scanend		ebx
+#define	scanendw	bx
+#define	chainlenwmask	edx /* high word: current chain len low word: s->wmask */
+#define	curmatch	rsi
+#define	curmatchd	esi
+#define	windowbestlen	r8
+#define	scanalign	r9
+#define	scanalignd	r9d
+#define	window		r10
+#define	bestlen		r11
+#define	bestlend	r11d
+#define	scanstart	r12d
+#define	scanstartw	r12w
+#define scan		r13
+#define nicematch	r14d
+#define	limit		r15
+#define	limitd		r15d
+#define prev		rcx
+
+/*
+ * The 258 is a "magic number, not a parameter -- changing it
+ * breaks the hell loose
+ */
+#define	MAX_MATCH	(258)
+#define	MIN_MATCH	(3)
+#define	MIN_LOOKAHEAD	(MAX_MATCH + MIN_MATCH + 1)
+#define	MAX_MATCH_8	((MAX_MATCH + 7) & ~7)
+
+/* stack frame offsets */
+#define	LocalVarsSize	(112)
+#define _chainlenwmask	( 8-LocalVarsSize)(%rsp)
+#define _windowbestlen	(16-LocalVarsSize)(%rsp)
+#define save_r14        (24-LocalVarsSize)(%rsp)
+#define save_rsi        (32-LocalVarsSize)(%rsp)
+#define save_rbx        (40-LocalVarsSize)(%rsp)
+#define save_r12        (56-LocalVarsSize)(%rsp)
+#define save_r13        (64-LocalVarsSize)(%rsp)
+#define save_r15        (80-LocalVarsSize)(%rsp)
+
+
+.globl	match_init, longest_match
+
+/*
+ * On AMD64 the first argument of a function (in our case -- the pointer to
+ * deflate_state structure) is passed in %rdi, hence our offsets below are
+ * all off of that.
+ */
+
+/* you can check the structure offset by running
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "deflate.h"
+
+void print_depl()
+{
+deflate_state ds;
+deflate_state *s=&ds;
+printf("size pointer=%u\n",(int)sizeof(void*));
+
+printf("#define dsWSize         (%3u)(%%rdi)\n",(int)(((char*)&(s->w_size))-((char*)s)));
+printf("#define dsWMask         (%3u)(%%rdi)\n",(int)(((char*)&(s->w_mask))-((char*)s)));
+printf("#define dsWindow        (%3u)(%%rdi)\n",(int)(((char*)&(s->window))-((char*)s)));
+printf("#define dsPrev          (%3u)(%%rdi)\n",(int)(((char*)&(s->prev))-((char*)s)));
+printf("#define dsMatchLen      (%3u)(%%rdi)\n",(int)(((char*)&(s->match_length))-((char*)s)));
+printf("#define dsPrevMatch     (%3u)(%%rdi)\n",(int)(((char*)&(s->prev_match))-((char*)s)));
+printf("#define dsStrStart      (%3u)(%%rdi)\n",(int)(((char*)&(s->strstart))-((char*)s)));
+printf("#define dsMatchStart    (%3u)(%%rdi)\n",(int)(((char*)&(s->match_start))-((char*)s)));
+printf("#define dsLookahead     (%3u)(%%rdi)\n",(int)(((char*)&(s->lookahead))-((char*)s)));
+printf("#define dsPrevLen       (%3u)(%%rdi)\n",(int)(((char*)&(s->prev_length))-((char*)s)));
+printf("#define dsMaxChainLen   (%3u)(%%rdi)\n",(int)(((char*)&(s->max_chain_length))-((char*)s)));
+printf("#define dsGoodMatch     (%3u)(%%rdi)\n",(int)(((char*)&(s->good_match))-((char*)s)));
+printf("#define dsNiceMatch     (%3u)(%%rdi)\n",(int)(((char*)&(s->nice_match))-((char*)s)));
+}
+
+*/
+
+
+/*
+  to compile for XCode 3.2 on MacOSX x86_64
+  - run "gcc -g -c -DXCODE_MAC_X64_STRUCTURE amd64-match.S"
+ */
+
+
+#ifndef CURRENT_LINX_XCODE_MAC_X64_STRUCTURE
+#define dsWSize		( 68)(%rdi)
+#define dsWMask		( 76)(%rdi)
+#define dsWindow	( 80)(%rdi)
+#define dsPrev		( 96)(%rdi)
+#define dsMatchLen	(144)(%rdi)
+#define dsPrevMatch	(148)(%rdi)
+#define dsStrStart	(156)(%rdi)
+#define dsMatchStart	(160)(%rdi)
+#define dsLookahead	(164)(%rdi)
+#define dsPrevLen	(168)(%rdi)
+#define dsMaxChainLen	(172)(%rdi)
+#define dsGoodMatch	(188)(%rdi)
+#define dsNiceMatch	(192)(%rdi)
+
+#else 
+
+#ifndef STRUCT_OFFSET
+#	define STRUCT_OFFSET	(0)
+#endif
+
+
+#define dsWSize		( 56 + STRUCT_OFFSET)(%rdi)
+#define dsWMask		( 64 + STRUCT_OFFSET)(%rdi)
+#define dsWindow	( 72 + STRUCT_OFFSET)(%rdi)
+#define dsPrev		( 88 + STRUCT_OFFSET)(%rdi)
+#define dsMatchLen	(136 + STRUCT_OFFSET)(%rdi)
+#define dsPrevMatch	(140 + STRUCT_OFFSET)(%rdi)
+#define dsStrStart	(148 + STRUCT_OFFSET)(%rdi)
+#define dsMatchStart	(152 + STRUCT_OFFSET)(%rdi)
+#define dsLookahead	(156 + STRUCT_OFFSET)(%rdi)
+#define dsPrevLen	(160 + STRUCT_OFFSET)(%rdi)
+#define dsMaxChainLen	(164 + STRUCT_OFFSET)(%rdi)
+#define dsGoodMatch	(180 + STRUCT_OFFSET)(%rdi)
+#define dsNiceMatch	(184 + STRUCT_OFFSET)(%rdi)
+
+#endif
+
+
+
+
+.text
+
+/* uInt longest_match(deflate_state *deflatestate, IPos curmatch) */
+
+longest_match:
+/*
+ * Retrieve the function arguments. %curmatch will hold cur_match
+ * throughout the entire function (passed via rsi on amd64).
+ * rdi will hold the pointer to the deflate_state (first arg on amd64)
+ */
+		mov     %rsi, save_rsi
+		mov     %rbx, save_rbx
+		mov	%r12, save_r12
+		mov     %r13, save_r13
+		mov     %r14, save_r14
+		mov     %r15, save_r15
+
+/* uInt wmask = s->w_mask;						*/
+/* unsigned chain_length = s->max_chain_length;				*/
+/* if (s->prev_length >= s->good_match) {				*/
+/*     chain_length >>= 2;						*/
+/* }									*/
+
+		movl	dsPrevLen, %eax
+		movl	dsGoodMatch, %ebx
+		cmpl	%ebx, %eax
+		movl	dsWMask, %eax
+		movl	dsMaxChainLen, %chainlenwmask
+		jl	LastMatchGood
+		shrl	$2, %chainlenwmask
+LastMatchGood:
+
+/* chainlen is decremented once beforehand so that the function can	*/
+/* use the sign flag instead of the zero flag for the exit test.	*/
+/* It is then shifted into the high word, to make room for the wmask	*/
+/* value, which it will always accompany.				*/
+
+		decl	%chainlenwmask
+		shll	$16, %chainlenwmask
+		orl	%eax, %chainlenwmask
+
+/* if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;	*/
+
+		movl	dsNiceMatch, %eax
+		movl	dsLookahead, %ebx
+		cmpl	%eax, %ebx
+		jl	LookaheadLess
+		movl	%eax, %ebx
+LookaheadLess:	movl	%ebx, %nicematch
+
+/* register Bytef *scan = s->window + s->strstart;			*/
+
+		mov	dsWindow, %window
+		movl	dsStrStart, %limitd
+		lea	(%limit, %window), %scan
+
+/* Determine how many bytes the scan ptr is off from being		*/
+/* dword-aligned.							*/
+
+		mov	%scan, %scanalign
+		negl	%scanalignd
+		andl	$3, %scanalignd
+
+/* IPos limit = s->strstart > (IPos)MAX_DIST(s) ?			*/
+/*     s->strstart - (IPos)MAX_DIST(s) : NIL;				*/
+
+		movl	dsWSize, %eax
+		subl	$MIN_LOOKAHEAD, %eax
+		xorl	%ecx, %ecx
+		subl	%eax, %limitd
+		cmovng	%ecx, %limitd
+
+/* int best_len = s->prev_length;					*/
+
+		movl	dsPrevLen, %bestlend
+
+/* Store the sum of s->window + best_len in %windowbestlen locally, and in memory.	*/
+
+		lea	(%window, %bestlen), %windowbestlen
+		mov	%windowbestlen, _windowbestlen
+
+/* register ush scan_start = *(ushf*)scan;				*/
+/* register ush scan_end   = *(ushf*)(scan+best_len-1);			*/
+/* Posf *prev = s->prev;						*/
+
+		movzwl	(%scan), %scanstart
+		movzwl	-1(%scan, %bestlen), %scanend
+		mov	dsPrev, %prev
+
+/* Jump into the main loop.						*/
+
+		movl	%chainlenwmask, _chainlenwmask
+		jmp	LoopEntry
+
+.balign 16
+
+/* do {
+ *     match = s->window + cur_match;
+ *     if (*(ushf*)(match+best_len-1) != scan_end ||
+ *         *(ushf*)match != scan_start) continue;
+ *     [...]
+ * } while ((cur_match = prev[cur_match & wmask]) > limit
+ *          && --chain_length != 0);
+ *
+ * Here is the inner loop of the function. The function will spend the
+ * majority of its time in this loop, and majority of that time will
+ * be spent in the first ten instructions.
+ */
+LookupLoop:
+		andl	%chainlenwmask, %curmatchd
+		movzwl	(%prev, %curmatch, 2), %curmatchd
+		cmpl	%limitd, %curmatchd
+		jbe	LeaveNow
+		subl	$0x00010000, %chainlenwmask
+		js	LeaveNow
+LoopEntry:	cmpw	-1(%windowbestlen, %curmatch), %scanendw
+		jne	LookupLoop
+		cmpw	%scanstartw, (%window, %curmatch)
+		jne	LookupLoop
+
+/* Store the current value of chainlen.					*/
+		movl	%chainlenwmask, _chainlenwmask
+
+/* %scan is the string under scrutiny, and %prev to the string we	*/
+/* are hoping to match it up with. In actuality, %esi and %edi are	*/
+/* both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and %edx is	*/
+/* initialized to -(MAX_MATCH_8 - scanalign).				*/
+
+		mov	$(-MAX_MATCH_8), %rdx
+		lea	(%curmatch, %window), %windowbestlen
+		lea	MAX_MATCH_8(%windowbestlen, %scanalign), %windowbestlen
+		lea	MAX_MATCH_8(%scan, %scanalign), %prev
+
+/* the prefetching below makes very little difference... */
+		prefetcht1	(%windowbestlen, %rdx)
+		prefetcht1	(%prev, %rdx)
+
+/*
+ * Test the strings for equality, 8 bytes at a time. At the end,
+ * adjust %rdx so that it is offset to the exact byte that mismatched.
+ *
+ * It should be confessed that this loop usually does not represent
+ * much of the total running time. Replacing it with a more
+ * straightforward "rep cmpsb" would not drastically degrade
+ * performance -- unrolling it, for example, makes no difference.
+ */
+
+#undef USE_SSE	/* works, but is 6-7% slower, than non-SSE... */
+
+LoopCmps:
+#ifdef USE_SSE
+		/* Preload the SSE registers */
+		movdqu	  (%windowbestlen, %rdx), %xmm1
+		movdqu	  (%prev, %rdx), %xmm2
+		pcmpeqb	%xmm2, %xmm1
+		movdqu	16(%windowbestlen, %rdx), %xmm3
+		movdqu	16(%prev, %rdx), %xmm4
+		pcmpeqb	%xmm4, %xmm3
+		movdqu	32(%windowbestlen, %rdx), %xmm5
+		movdqu	32(%prev, %rdx), %xmm6
+		pcmpeqb	%xmm6, %xmm5
+		movdqu	48(%windowbestlen, %rdx), %xmm7
+		movdqu	48(%prev, %rdx), %xmm8
+		pcmpeqb	%xmm8, %xmm7
+
+		/* Check the comparisions' results */
+		pmovmskb %xmm1, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		/* this is the only iteration of the loop with a possibility of having
+		   incremented rdx by 0x108 (each loop iteration add 16*4 = 0x40 
+		   and (0x40*4)+8=0x108 */
+		add	$8, %rdx
+		jz LenMaximum
+		add	$8, %rdx
+
+		
+		pmovmskb %xmm3, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		
+		add	$16, %rdx
+
+
+		pmovmskb %xmm5, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		add	$16, %rdx
+
+
+		pmovmskb %xmm7, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		add	$16, %rdx
+		
+		jmp	LoopCmps
+LeaveLoopCmps:	add	%rax, %rdx
+#else
+		mov	(%windowbestlen, %rdx), %rax
+		xor	(%prev, %rdx), %rax
+		jnz	LeaveLoopCmps
+		
+		mov	8(%windowbestlen, %rdx), %rax
+		xor	8(%prev, %rdx), %rax
+		jnz	LeaveLoopCmps8
+
+		mov	16(%windowbestlen, %rdx), %rax
+		xor	16(%prev, %rdx), %rax
+		jnz	LeaveLoopCmps16
+				
+		add	$24, %rdx
+		jnz	LoopCmps
+		jmp	LenMaximum
+#	if 0
+/*
+ * This three-liner is tantalizingly simple, but bsf is a slow instruction,
+ * and the complicated alternative down below is quite a bit faster. Sad...
+ */
+
+LeaveLoopCmps:	bsf	%rax, %rax /* find the first non-zero bit */
+		shrl	$3, %eax /* divide by 8 to get the byte */
+		add	%rax, %rdx
+#	else
+LeaveLoopCmps16:
+		add	$8, %rdx
+LeaveLoopCmps8:
+		add	$8, %rdx
+LeaveLoopCmps:	testl   $0xFFFFFFFF, %eax /* Check the first 4 bytes */
+		jnz     Check16
+		add     $4, %rdx
+		shr     $32, %rax
+Check16:        testw   $0xFFFF, %ax
+		jnz     LenLower
+		add	$2, %rdx
+		shrl	$16, %eax
+LenLower:	subb	$1, %al
+		adc	$0, %rdx
+#	endif
+#endif
+
+/* Calculate the length of the match. If it is longer than MAX_MATCH,	*/
+/* then automatically accept it as the best possible match and leave.	*/
+
+		lea	(%prev, %rdx), %rax
+		sub	%scan, %rax
+		cmpl	$MAX_MATCH, %eax
+		jge	LenMaximum
+
+/* If the length of the match is not longer than the best match we	*/
+/* have so far, then forget it and return to the lookup loop.		*/
+
+		cmpl	%bestlend, %eax
+		jg	LongerMatch
+		mov	_windowbestlen, %windowbestlen
+		mov	dsPrev, %prev
+		movl	_chainlenwmask, %edx
+		jmp	LookupLoop
+
+/*         s->match_start = cur_match;					*/
+/*         best_len = len;						*/
+/*         if (len >= nice_match) break;				*/
+/*         scan_end = *(ushf*)(scan+best_len-1);			*/
+
+LongerMatch:
+		movl	%eax, %bestlend
+		movl	%curmatchd, dsMatchStart
+		cmpl	%nicematch, %eax
+		jge	LeaveNow
+
+		lea	(%window, %bestlen), %windowbestlen
+		mov	%windowbestlen, _windowbestlen
+
+		movzwl	-1(%scan, %rax), %scanend
+		mov	dsPrev, %prev
+		movl	_chainlenwmask, %chainlenwmask
+		jmp	LookupLoop
+
+/* Accept the current string, with the maximum possible length.		*/
+
+LenMaximum:
+		movl	$MAX_MATCH, %bestlend
+		movl	%curmatchd, dsMatchStart
+
+/* if ((uInt)best_len <= s->lookahead) return (uInt)best_len;		*/
+/* return s->lookahead;							*/
+
+LeaveNow:
+		movl	dsLookahead, %eax
+		cmpl	%eax, %bestlend
+		cmovngl	%bestlend, %eax
+LookaheadRet:
+
+/* Restore the registers and return from whence we came.			*/
+
+	mov	save_rsi, %rsi
+	mov	save_rbx, %rbx
+	mov	save_r12, %r12
+	mov	save_r13, %r13
+	mov	save_r14, %r14
+	mov	save_r15, %r15
+
+	ret
+
+match_init:	ret
diff --git a/xs/src/png/zlib/contrib/asm686/README.686 b/xs/src/png/zlib/contrib/asm686/README.686
new file mode 100644
index 000000000..a0bf3bea4
--- /dev/null
+++ b/xs/src/png/zlib/contrib/asm686/README.686
@@ -0,0 +1,51 @@
+This is a patched version of zlib, modified to use
+Pentium-Pro-optimized assembly code in the deflation algorithm. The
+files changed/added by this patch are:
+
+README.686
+match.S
+
+The speedup that this patch provides varies, depending on whether the
+compiler used to build the original version of zlib falls afoul of the
+PPro's speed traps. My own tests show a speedup of around 10-20% at
+the default compression level, and 20-30% using -9, against a version
+compiled using gcc 2.7.2.3. Your mileage may vary.
+
+Note that this code has been tailored for the PPro/PII in particular,
+and will not perform particuarly well on a Pentium.
+
+If you are using an assembler other than GNU as, you will have to
+translate match.S to use your assembler's syntax. (Have fun.)
+
+Brian Raiter
+breadbox@muppetlabs.com
+April, 1998
+
+
+Added for zlib 1.1.3:
+
+The patches come from
+http://www.muppetlabs.com/~breadbox/software/assembly.html
+
+To compile zlib with this asm file, copy match.S to the zlib directory
+then do:
+
+CFLAGS="-O3 -DASMV" ./configure
+make OBJA=match.o
+
+
+Update:
+
+I've been ignoring these assembly routines for years, believing that
+gcc's generated code had caught up with it sometime around gcc 2.95
+and the major rearchitecting of the Pentium 4. However, I recently
+learned that, despite what I believed, this code still has some life
+in it. On the Pentium 4 and AMD64 chips, it continues to run about 8%
+faster than the code produced by gcc 4.1.
+
+In acknowledgement of its continuing usefulness, I've altered the
+license to match that of the rest of zlib. Share and Enjoy!
+
+Brian Raiter
+breadbox@muppetlabs.com
+April, 2007
diff --git a/xs/src/png/zlib/contrib/asm686/match.S b/xs/src/png/zlib/contrib/asm686/match.S
new file mode 100644
index 000000000..fa4210927
--- /dev/null
+++ b/xs/src/png/zlib/contrib/asm686/match.S
@@ -0,0 +1,357 @@
+/* match.S -- x86 assembly version of the zlib longest_match() function.
+ * Optimized for the Intel 686 chips (PPro and later).
+ *
+ * Copyright (C) 1998, 2007 Brian Raiter <breadbox@muppetlabs.com>
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the author be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ */
+
+#ifndef NO_UNDERLINE
+#define	match_init	_match_init
+#define	longest_match	_longest_match
+#endif
+
+#define	MAX_MATCH	(258)
+#define	MIN_MATCH	(3)
+#define	MIN_LOOKAHEAD	(MAX_MATCH + MIN_MATCH + 1)
+#define	MAX_MATCH_8	((MAX_MATCH + 7) & ~7)
+
+/* stack frame offsets */
+
+#define	chainlenwmask		0	/* high word: current chain len	*/
+					/* low word: s->wmask		*/
+#define	window			4	/* local copy of s->window	*/
+#define	windowbestlen		8	/* s->window + bestlen		*/
+#define	scanstart		16	/* first two bytes of string	*/
+#define	scanend			12	/* last two bytes of string	*/
+#define	scanalign		20	/* dword-misalignment of string	*/
+#define	nicematch		24	/* a good enough match size	*/
+#define	bestlen			28	/* size of best match so far	*/
+#define	scan			32	/* ptr to string wanting match	*/
+
+#define	LocalVarsSize		(36)
+/*	saved ebx		36 */
+/*	saved edi		40 */
+/*	saved esi		44 */
+/*	saved ebp		48 */
+/*	return address		52 */
+#define	deflatestate		56	/* the function arguments	*/
+#define	curmatch		60
+
+/* All the +zlib1222add offsets are due to the addition of fields
+ *  in zlib in the deflate_state structure since the asm code was first written
+ * (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
+ * (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
+ * if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
+ */
+
+#define zlib1222add		(8)
+
+#define	dsWSize			(36+zlib1222add)
+#define	dsWMask			(44+zlib1222add)
+#define	dsWindow		(48+zlib1222add)
+#define	dsPrev			(56+zlib1222add)
+#define	dsMatchLen		(88+zlib1222add)
+#define	dsPrevMatch		(92+zlib1222add)
+#define	dsStrStart		(100+zlib1222add)
+#define	dsMatchStart		(104+zlib1222add)
+#define	dsLookahead		(108+zlib1222add)
+#define	dsPrevLen		(112+zlib1222add)
+#define	dsMaxChainLen		(116+zlib1222add)
+#define	dsGoodMatch		(132+zlib1222add)
+#define	dsNiceMatch		(136+zlib1222add)
+
+
+.file "match.S"
+
+.globl	match_init, longest_match
+
+.text
+
+/* uInt longest_match(deflate_state *deflatestate, IPos curmatch) */
+.cfi_sections	.debug_frame
+
+longest_match:
+
+.cfi_startproc
+/* Save registers that the compiler may be using, and adjust %esp to	*/
+/* make room for our stack frame.					*/
+
+		pushl	%ebp
+		.cfi_def_cfa_offset 8
+		.cfi_offset ebp, -8
+		pushl	%edi
+		.cfi_def_cfa_offset 12
+		pushl	%esi
+		.cfi_def_cfa_offset 16
+		pushl	%ebx
+		.cfi_def_cfa_offset 20
+		subl	$LocalVarsSize, %esp
+		.cfi_def_cfa_offset LocalVarsSize+20
+
+/* Retrieve the function arguments. %ecx will hold cur_match		*/
+/* throughout the entire function. %edx will hold the pointer to the	*/
+/* deflate_state structure during the function's setup (before		*/
+/* entering the main loop).						*/
+
+		movl	deflatestate(%esp), %edx
+		movl	curmatch(%esp), %ecx
+
+/* uInt wmask = s->w_mask;						*/
+/* unsigned chain_length = s->max_chain_length;				*/
+/* if (s->prev_length >= s->good_match) {				*/
+/*     chain_length >>= 2;						*/
+/* }									*/
+ 
+		movl	dsPrevLen(%edx), %eax
+		movl	dsGoodMatch(%edx), %ebx
+		cmpl	%ebx, %eax
+		movl	dsWMask(%edx), %eax
+		movl	dsMaxChainLen(%edx), %ebx
+		jl	LastMatchGood
+		shrl	$2, %ebx
+LastMatchGood:
+
+/* chainlen is decremented once beforehand so that the function can	*/
+/* use the sign flag instead of the zero flag for the exit test.	*/
+/* It is then shifted into the high word, to make room for the wmask	*/
+/* value, which it will always accompany.				*/
+
+		decl	%ebx
+		shll	$16, %ebx
+		orl	%eax, %ebx
+		movl	%ebx, chainlenwmask(%esp)
+
+/* if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;	*/
+
+		movl	dsNiceMatch(%edx), %eax
+		movl	dsLookahead(%edx), %ebx
+		cmpl	%eax, %ebx
+		jl	LookaheadLess
+		movl	%eax, %ebx
+LookaheadLess:	movl	%ebx, nicematch(%esp)
+
+/* register Bytef *scan = s->window + s->strstart;			*/
+
+		movl	dsWindow(%edx), %esi
+		movl	%esi, window(%esp)
+		movl	dsStrStart(%edx), %ebp
+		lea	(%esi,%ebp), %edi
+		movl	%edi, scan(%esp)
+
+/* Determine how many bytes the scan ptr is off from being		*/
+/* dword-aligned.							*/
+
+		movl	%edi, %eax
+		negl	%eax
+		andl	$3, %eax
+		movl	%eax, scanalign(%esp)
+
+/* IPos limit = s->strstart > (IPos)MAX_DIST(s) ?			*/
+/*     s->strstart - (IPos)MAX_DIST(s) : NIL;				*/
+
+		movl	dsWSize(%edx), %eax
+		subl	$MIN_LOOKAHEAD, %eax
+		subl	%eax, %ebp
+		jg	LimitPositive
+		xorl	%ebp, %ebp
+LimitPositive:
+
+/* int best_len = s->prev_length;					*/
+
+		movl	dsPrevLen(%edx), %eax
+		movl	%eax, bestlen(%esp)
+
+/* Store the sum of s->window + best_len in %esi locally, and in %esi.	*/
+
+		addl	%eax, %esi
+		movl	%esi, windowbestlen(%esp)
+
+/* register ush scan_start = *(ushf*)scan;				*/
+/* register ush scan_end   = *(ushf*)(scan+best_len-1);			*/
+/* Posf *prev = s->prev;						*/
+
+		movzwl	(%edi), %ebx
+		movl	%ebx, scanstart(%esp)
+		movzwl	-1(%edi,%eax), %ebx
+		movl	%ebx, scanend(%esp)
+		movl	dsPrev(%edx), %edi
+
+/* Jump into the main loop.						*/
+
+		movl	chainlenwmask(%esp), %edx
+		jmp	LoopEntry
+
+.balign 16
+
+/* do {
+ *     match = s->window + cur_match;
+ *     if (*(ushf*)(match+best_len-1) != scan_end ||
+ *         *(ushf*)match != scan_start) continue;
+ *     [...]
+ * } while ((cur_match = prev[cur_match & wmask]) > limit
+ *          && --chain_length != 0);
+ *
+ * Here is the inner loop of the function. The function will spend the
+ * majority of its time in this loop, and majority of that time will
+ * be spent in the first ten instructions.
+ *
+ * Within this loop:
+ * %ebx = scanend
+ * %ecx = curmatch
+ * %edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
+ * %esi = windowbestlen - i.e., (window + bestlen)
+ * %edi = prev
+ * %ebp = limit
+ */
+LookupLoop:
+		andl	%edx, %ecx
+		movzwl	(%edi,%ecx,2), %ecx
+		cmpl	%ebp, %ecx
+		jbe	LeaveNow
+		subl	$0x00010000, %edx
+		js	LeaveNow
+LoopEntry:	movzwl	-1(%esi,%ecx), %eax
+		cmpl	%ebx, %eax
+		jnz	LookupLoop
+		movl	window(%esp), %eax
+		movzwl	(%eax,%ecx), %eax
+		cmpl	scanstart(%esp), %eax
+		jnz	LookupLoop
+
+/* Store the current value of chainlen.					*/
+
+		movl	%edx, chainlenwmask(%esp)
+
+/* Point %edi to the string under scrutiny, and %esi to the string we	*/
+/* are hoping to match it up with. In actuality, %esi and %edi are	*/
+/* both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and %edx is	*/
+/* initialized to -(MAX_MATCH_8 - scanalign).				*/
+
+		movl	window(%esp), %esi
+		movl	scan(%esp), %edi
+		addl	%ecx, %esi
+		movl	scanalign(%esp), %eax
+		movl	$(-MAX_MATCH_8), %edx
+		lea	MAX_MATCH_8(%edi,%eax), %edi
+		lea	MAX_MATCH_8(%esi,%eax), %esi
+
+/* Test the strings for equality, 8 bytes at a time. At the end,
+ * adjust %edx so that it is offset to the exact byte that mismatched.
+ *
+ * We already know at this point that the first three bytes of the
+ * strings match each other, and they can be safely passed over before
+ * starting the compare loop. So what this code does is skip over 0-3
+ * bytes, as much as necessary in order to dword-align the %edi
+ * pointer. (%esi will still be misaligned three times out of four.)
+ *
+ * It should be confessed that this loop usually does not represent
+ * much of the total running time. Replacing it with a more
+ * straightforward "rep cmpsb" would not drastically degrade
+ * performance.
+ */
+LoopCmps:
+		movl	(%esi,%edx), %eax
+		xorl	(%edi,%edx), %eax
+		jnz	LeaveLoopCmps
+		movl	4(%esi,%edx), %eax
+		xorl	4(%edi,%edx), %eax
+		jnz	LeaveLoopCmps4
+		addl	$8, %edx
+		jnz	LoopCmps
+		jmp	LenMaximum
+LeaveLoopCmps4:	addl	$4, %edx
+LeaveLoopCmps:	testl	$0x0000FFFF, %eax
+		jnz	LenLower
+		addl	$2, %edx
+		shrl	$16, %eax
+LenLower:	subb	$1, %al
+		adcl	$0, %edx
+
+/* Calculate the length of the match. If it is longer than MAX_MATCH,	*/
+/* then automatically accept it as the best possible match and leave.	*/
+
+		lea	(%edi,%edx), %eax
+		movl	scan(%esp), %edi
+		subl	%edi, %eax
+		cmpl	$MAX_MATCH, %eax
+		jge	LenMaximum
+
+/* If the length of the match is not longer than the best match we	*/
+/* have so far, then forget it and return to the lookup loop.		*/
+
+		movl	deflatestate(%esp), %edx
+		movl	bestlen(%esp), %ebx
+		cmpl	%ebx, %eax
+		jg	LongerMatch
+		movl	windowbestlen(%esp), %esi
+		movl	dsPrev(%edx), %edi
+		movl	scanend(%esp), %ebx
+		movl	chainlenwmask(%esp), %edx
+		jmp	LookupLoop
+
+/*         s->match_start = cur_match;					*/
+/*         best_len = len;						*/
+/*         if (len >= nice_match) break;				*/
+/*         scan_end = *(ushf*)(scan+best_len-1);			*/
+
+LongerMatch:	movl	nicematch(%esp), %ebx
+		movl	%eax, bestlen(%esp)
+		movl	%ecx, dsMatchStart(%edx)
+		cmpl	%ebx, %eax
+		jge	LeaveNow
+		movl	window(%esp), %esi
+		addl	%eax, %esi
+		movl	%esi, windowbestlen(%esp)
+		movzwl	-1(%edi,%eax), %ebx
+		movl	dsPrev(%edx), %edi
+		movl	%ebx, scanend(%esp)
+		movl	chainlenwmask(%esp), %edx
+		jmp	LookupLoop
+
+/* Accept the current string, with the maximum possible length.		*/
+
+LenMaximum:	movl	deflatestate(%esp), %edx
+		movl	$MAX_MATCH, bestlen(%esp)
+		movl	%ecx, dsMatchStart(%edx)
+
+/* if ((uInt)best_len <= s->lookahead) return (uInt)best_len;		*/
+/* return s->lookahead;							*/
+
+LeaveNow:
+		movl	deflatestate(%esp), %edx
+		movl	bestlen(%esp), %ebx
+		movl	dsLookahead(%edx), %eax
+		cmpl	%eax, %ebx
+		jg	LookaheadRet
+		movl	%ebx, %eax
+LookaheadRet:
+
+/* Restore the stack and return from whence we came.			*/
+
+		addl	$LocalVarsSize, %esp
+		.cfi_def_cfa_offset 20
+		popl	%ebx
+		.cfi_def_cfa_offset 16
+		popl	%esi
+		.cfi_def_cfa_offset 12
+		popl	%edi
+		.cfi_def_cfa_offset 8
+		popl	%ebp
+		.cfi_def_cfa_offset 4
+.cfi_endproc
+match_init:	ret
diff --git a/xs/src/png/zlib/contrib/blast/Makefile b/xs/src/png/zlib/contrib/blast/Makefile
new file mode 100644
index 000000000..9be80bafe
--- /dev/null
+++ b/xs/src/png/zlib/contrib/blast/Makefile
@@ -0,0 +1,8 @@
+blast: blast.c blast.h
+	cc -DTEST -o blast blast.c
+
+test: blast
+	blast < test.pk | cmp - test.txt
+
+clean:
+	rm -f blast blast.o
diff --git a/xs/src/png/zlib/contrib/blast/README b/xs/src/png/zlib/contrib/blast/README
new file mode 100644
index 000000000..e3a60b3f5
--- /dev/null
+++ b/xs/src/png/zlib/contrib/blast/README
@@ -0,0 +1,4 @@
+Read blast.h for purpose and usage.
+
+Mark Adler
+madler@alumni.caltech.edu
diff --git a/xs/src/png/zlib/contrib/blast/blast.c b/xs/src/png/zlib/contrib/blast/blast.c
new file mode 100644
index 000000000..e6e659073
--- /dev/null
+++ b/xs/src/png/zlib/contrib/blast/blast.c
@@ -0,0 +1,466 @@
+/* blast.c
+ * Copyright (C) 2003, 2012, 2013 Mark Adler
+ * For conditions of distribution and use, see copyright notice in blast.h
+ * version 1.3, 24 Aug 2013
+ *
+ * blast.c decompresses data compressed by the PKWare Compression Library.
+ * This function provides functionality similar to the explode() function of
+ * the PKWare library, hence the name "blast".
+ *
+ * This decompressor is based on the excellent format description provided by
+ * Ben Rudiak-Gould in comp.compression on August 13, 2001.  Interestingly, the
+ * example Ben provided in the post is incorrect.  The distance 110001 should
+ * instead be 111000.  When corrected, the example byte stream becomes:
+ *
+ *    00 04 82 24 25 8f 80 7f
+ *
+ * which decompresses to "AIAIAIAIAIAIA" (without the quotes).
+ */
+
+/*
+ * Change history:
+ *
+ * 1.0  12 Feb 2003     - First version
+ * 1.1  16 Feb 2003     - Fixed distance check for > 4 GB uncompressed data
+ * 1.2  24 Oct 2012     - Add note about using binary mode in stdio
+ *                      - Fix comparisons of differently signed integers
+ * 1.3  24 Aug 2013     - Return unused input from blast()
+ *                      - Fix test code to correctly report unused input
+ *                      - Enable the provision of initial input to blast()
+ */
+
+#include <stddef.h>             /* for NULL */
+#include <setjmp.h>             /* for setjmp(), longjmp(), and jmp_buf */
+#include "blast.h"              /* prototype for blast() */
+
+#define local static            /* for local function definitions */
+#define MAXBITS 13              /* maximum code length */
+#define MAXWIN 4096             /* maximum window size */
+
+/* input and output state */
+struct state {
+    /* input state */
+    blast_in infun;             /* input function provided by user */
+    void *inhow;                /* opaque information passed to infun() */
+    unsigned char *in;          /* next input location */
+    unsigned left;              /* available input at in */
+    int bitbuf;                 /* bit buffer */
+    int bitcnt;                 /* number of bits in bit buffer */
+
+    /* input limit error return state for bits() and decode() */
+    jmp_buf env;
+
+    /* output state */
+    blast_out outfun;           /* output function provided by user */
+    void *outhow;               /* opaque information passed to outfun() */
+    unsigned next;              /* index of next write location in out[] */
+    int first;                  /* true to check distances (for first 4K) */
+    unsigned char out[MAXWIN];  /* output buffer and sliding window */
+};
+
+/*
+ * Return need bits from the input stream.  This always leaves less than
+ * eight bits in the buffer.  bits() works properly for need == 0.
+ *
+ * Format notes:
+ *
+ * - Bits are stored in bytes from the least significant bit to the most
+ *   significant bit.  Therefore bits are dropped from the bottom of the bit
+ *   buffer, using shift right, and new bytes are appended to the top of the
+ *   bit buffer, using shift left.
+ */
+local int bits(struct state *s, int need)
+{
+    int val;            /* bit accumulator */
+
+    /* load at least need bits into val */
+    val = s->bitbuf;
+    while (s->bitcnt < need) {
+        if (s->left == 0) {
+            s->left = s->infun(s->inhow, &(s->in));
+            if (s->left == 0) longjmp(s->env, 1);       /* out of input */
+        }
+        val |= (int)(*(s->in)++) << s->bitcnt;          /* load eight bits */
+        s->left--;
+        s->bitcnt += 8;
+    }
+
+    /* drop need bits and update buffer, always zero to seven bits left */
+    s->bitbuf = val >> need;
+    s->bitcnt -= need;
+
+    /* return need bits, zeroing the bits above that */
+    return val & ((1 << need) - 1);
+}
+
+/*
+ * Huffman code decoding tables.  count[1..MAXBITS] is the number of symbols of
+ * each length, which for a canonical code are stepped through in order.
+ * symbol[] are the symbol values in canonical order, where the number of
+ * entries is the sum of the counts in count[].  The decoding process can be
+ * seen in the function decode() below.
+ */
+struct huffman {
+    short *count;       /* number of symbols of each length */
+    short *symbol;      /* canonically ordered symbols */
+};
+
+/*
+ * Decode a code from the stream s using huffman table h.  Return the symbol or
+ * a negative value if there is an error.  If all of the lengths are zero, i.e.
+ * an empty code, or if the code is incomplete and an invalid code is received,
+ * then -9 is returned after reading MAXBITS bits.
+ *
+ * Format notes:
+ *
+ * - The codes as stored in the compressed data are bit-reversed relative to
+ *   a simple integer ordering of codes of the same lengths.  Hence below the
+ *   bits are pulled from the compressed data one at a time and used to
+ *   build the code value reversed from what is in the stream in order to
+ *   permit simple integer comparisons for decoding.
+ *
+ * - The first code for the shortest length is all ones.  Subsequent codes of
+ *   the same length are simply integer decrements of the previous code.  When
+ *   moving up a length, a one bit is appended to the code.  For a complete
+ *   code, the last code of the longest length will be all zeros.  To support
+ *   this ordering, the bits pulled during decoding are inverted to apply the
+ *   more "natural" ordering starting with all zeros and incrementing.
+ */
+local int decode(struct state *s, struct huffman *h)
+{
+    int len;            /* current number of bits in code */
+    int code;           /* len bits being decoded */
+    int first;          /* first code of length len */
+    int count;          /* number of codes of length len */
+    int index;          /* index of first code of length len in symbol table */
+    int bitbuf;         /* bits from stream */
+    int left;           /* bits left in next or left to process */
+    short *next;        /* next number of codes */
+
+    bitbuf = s->bitbuf;
+    left = s->bitcnt;
+    code = first = index = 0;
+    len = 1;
+    next = h->count + 1;
+    while (1) {
+        while (left--) {
+            code |= (bitbuf & 1) ^ 1;   /* invert code */
+            bitbuf >>= 1;
+            count = *next++;
+            if (code < first + count) { /* if length len, return symbol */
+                s->bitbuf = bitbuf;
+                s->bitcnt = (s->bitcnt - len) & 7;
+                return h->symbol[index + (code - first)];
+            }
+            index += count;             /* else update for next length */
+            first += count;
+            first <<= 1;
+            code <<= 1;
+            len++;
+        }
+        left = (MAXBITS+1) - len;
+        if (left == 0) break;
+        if (s->left == 0) {
+            s->left = s->infun(s->inhow, &(s->in));
+            if (s->left == 0) longjmp(s->env, 1);       /* out of input */
+        }
+        bitbuf = *(s->in)++;
+        s->left--;
+        if (left > 8) left = 8;
+    }
+    return -9;                          /* ran out of codes */
+}
+
+/*
+ * Given a list of repeated code lengths rep[0..n-1], where each byte is a
+ * count (high four bits + 1) and a code length (low four bits), generate the
+ * list of code lengths.  This compaction reduces the size of the object code.
+ * Then given the list of code lengths length[0..n-1] representing a canonical
+ * Huffman code for n symbols, construct the tables required to decode those
+ * codes.  Those tables are the number of codes of each length, and the symbols
+ * sorted by length, retaining their original order within each length.  The
+ * return value is zero for a complete code set, negative for an over-
+ * subscribed code set, and positive for an incomplete code set.  The tables
+ * can be used if the return value is zero or positive, but they cannot be used
+ * if the return value is negative.  If the return value is zero, it is not
+ * possible for decode() using that table to return an error--any stream of
+ * enough bits will resolve to a symbol.  If the return value is positive, then
+ * it is possible for decode() using that table to return an error for received
+ * codes past the end of the incomplete lengths.
+ */
+local int construct(struct huffman *h, const unsigned char *rep, int n)
+{
+    int symbol;         /* current symbol when stepping through length[] */
+    int len;            /* current length when stepping through h->count[] */
+    int left;           /* number of possible codes left of current length */
+    short offs[MAXBITS+1];      /* offsets in symbol table for each length */
+    short length[256];  /* code lengths */
+
+    /* convert compact repeat counts into symbol bit length list */
+    symbol = 0;
+    do {
+        len = *rep++;
+        left = (len >> 4) + 1;
+        len &= 15;
+        do {
+            length[symbol++] = len;
+        } while (--left);
+    } while (--n);
+    n = symbol;
+
+    /* count number of codes of each length */
+    for (len = 0; len <= MAXBITS; len++)
+        h->count[len] = 0;
+    for (symbol = 0; symbol < n; symbol++)
+        (h->count[length[symbol]])++;   /* assumes lengths are within bounds */
+    if (h->count[0] == n)               /* no codes! */
+        return 0;                       /* complete, but decode() will fail */
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;                           /* one possible code of zero length */
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;                     /* one more bit, double codes left */
+        left -= h->count[len];          /* deduct count from possible codes */
+        if (left < 0) return left;      /* over-subscribed--return negative */
+    }                                   /* left > 0 means incomplete */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + h->count[len];
+
+    /*
+     * put symbols in table sorted by length, by symbol order within each
+     * length
+     */
+    for (symbol = 0; symbol < n; symbol++)
+        if (length[symbol] != 0)
+            h->symbol[offs[length[symbol]]++] = symbol;
+
+    /* return zero for complete set, positive for incomplete set */
+    return left;
+}
+
+/*
+ * Decode PKWare Compression Library stream.
+ *
+ * Format notes:
+ *
+ * - First byte is 0 if literals are uncoded or 1 if they are coded.  Second
+ *   byte is 4, 5, or 6 for the number of extra bits in the distance code.
+ *   This is the base-2 logarithm of the dictionary size minus six.
+ *
+ * - Compressed data is a combination of literals and length/distance pairs
+ *   terminated by an end code.  Literals are either Huffman coded or
+ *   uncoded bytes.  A length/distance pair is a coded length followed by a
+ *   coded distance to represent a string that occurs earlier in the
+ *   uncompressed data that occurs again at the current location.
+ *
+ * - A bit preceding a literal or length/distance pair indicates which comes
+ *   next, 0 for literals, 1 for length/distance.
+ *
+ * - If literals are uncoded, then the next eight bits are the literal, in the
+ *   normal bit order in the stream, i.e. no bit-reversal is needed. Similarly,
+ *   no bit reversal is needed for either the length extra bits or the distance
+ *   extra bits.
+ *
+ * - Literal bytes are simply written to the output.  A length/distance pair is
+ *   an instruction to copy previously uncompressed bytes to the output.  The
+ *   copy is from distance bytes back in the output stream, copying for length
+ *   bytes.
+ *
+ * - Distances pointing before the beginning of the output data are not
+ *   permitted.
+ *
+ * - Overlapped copies, where the length is greater than the distance, are
+ *   allowed and common.  For example, a distance of one and a length of 518
+ *   simply copies the last byte 518 times.  A distance of four and a length of
+ *   twelve copies the last four bytes three times.  A simple forward copy
+ *   ignoring whether the length is greater than the distance or not implements
+ *   this correctly.
+ */
+local int decomp(struct state *s)
+{
+    int lit;            /* true if literals are coded */
+    int dict;           /* log2(dictionary size) - 6 */
+    int symbol;         /* decoded symbol, extra bits for distance */
+    int len;            /* length for copy */
+    unsigned dist;      /* distance for copy */
+    int copy;           /* copy counter */
+    unsigned char *from, *to;   /* copy pointers */
+    static int virgin = 1;                              /* build tables once */
+    static short litcnt[MAXBITS+1], litsym[256];        /* litcode memory */
+    static short lencnt[MAXBITS+1], lensym[16];         /* lencode memory */
+    static short distcnt[MAXBITS+1], distsym[64];       /* distcode memory */
+    static struct huffman litcode = {litcnt, litsym};   /* length code */
+    static struct huffman lencode = {lencnt, lensym};   /* length code */
+    static struct huffman distcode = {distcnt, distsym};/* distance code */
+        /* bit lengths of literal codes */
+    static const unsigned char litlen[] = {
+        11, 124, 8, 7, 28, 7, 188, 13, 76, 4, 10, 8, 12, 10, 12, 10, 8, 23, 8,
+        9, 7, 6, 7, 8, 7, 6, 55, 8, 23, 24, 12, 11, 7, 9, 11, 12, 6, 7, 22, 5,
+        7, 24, 6, 11, 9, 6, 7, 22, 7, 11, 38, 7, 9, 8, 25, 11, 8, 11, 9, 12,
+        8, 12, 5, 38, 5, 38, 5, 11, 7, 5, 6, 21, 6, 10, 53, 8, 7, 24, 10, 27,
+        44, 253, 253, 253, 252, 252, 252, 13, 12, 45, 12, 45, 12, 61, 12, 45,
+        44, 173};
+        /* bit lengths of length codes 0..15 */
+    static const unsigned char lenlen[] = {2, 35, 36, 53, 38, 23};
+        /* bit lengths of distance codes 0..63 */
+    static const unsigned char distlen[] = {2, 20, 53, 230, 247, 151, 248};
+    static const short base[16] = {     /* base for length codes */
+        3, 2, 4, 5, 6, 7, 8, 9, 10, 12, 16, 24, 40, 72, 136, 264};
+    static const char extra[16] = {     /* extra bits for length codes */
+        0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8};
+
+    /* set up decoding tables (once--might not be thread-safe) */
+    if (virgin) {
+        construct(&litcode, litlen, sizeof(litlen));
+        construct(&lencode, lenlen, sizeof(lenlen));
+        construct(&distcode, distlen, sizeof(distlen));
+        virgin = 0;
+    }
+
+    /* read header */
+    lit = bits(s, 8);
+    if (lit > 1) return -1;
+    dict = bits(s, 8);
+    if (dict < 4 || dict > 6) return -2;
+
+    /* decode literals and length/distance pairs */
+    do {
+        if (bits(s, 1)) {
+            /* get length */
+            symbol = decode(s, &lencode);
+            len = base[symbol] + bits(s, extra[symbol]);
+            if (len == 519) break;              /* end code */
+
+            /* get distance */
+            symbol = len == 2 ? 2 : dict;
+            dist = decode(s, &distcode) << symbol;
+            dist += bits(s, symbol);
+            dist++;
+            if (s->first && dist > s->next)
+                return -3;              /* distance too far back */
+
+            /* copy length bytes from distance bytes back */
+            do {
+                to = s->out + s->next;
+                from = to - dist;
+                copy = MAXWIN;
+                if (s->next < dist) {
+                    from += copy;
+                    copy = dist;
+                }
+                copy -= s->next;
+                if (copy > len) copy = len;
+                len -= copy;
+                s->next += copy;
+                do {
+                    *to++ = *from++;
+                } while (--copy);
+                if (s->next == MAXWIN) {
+                    if (s->outfun(s->outhow, s->out, s->next)) return 1;
+                    s->next = 0;
+                    s->first = 0;
+                }
+            } while (len != 0);
+        }
+        else {
+            /* get literal and write it */
+            symbol = lit ? decode(s, &litcode) : bits(s, 8);
+            s->out[s->next++] = symbol;
+            if (s->next == MAXWIN) {
+                if (s->outfun(s->outhow, s->out, s->next)) return 1;
+                s->next = 0;
+                s->first = 0;
+            }
+        }
+    } while (1);
+    return 0;
+}
+
+/* See comments in blast.h */
+int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
+          unsigned *left, unsigned char **in)
+{
+    struct state s;             /* input/output state */
+    int err;                    /* return value */
+
+    /* initialize input state */
+    s.infun = infun;
+    s.inhow = inhow;
+    if (left != NULL && *left) {
+        s.left = *left;
+        s.in = *in;
+    }
+    else
+        s.left = 0;
+    s.bitbuf = 0;
+    s.bitcnt = 0;
+
+    /* initialize output state */
+    s.outfun = outfun;
+    s.outhow = outhow;
+    s.next = 0;
+    s.first = 1;
+
+    /* return if bits() or decode() tries to read past available input */
+    if (setjmp(s.env) != 0)             /* if came back here via longjmp(), */
+        err = 2;                        /*  then skip decomp(), return error */
+    else
+        err = decomp(&s);               /* decompress */
+
+    /* return unused input */
+    if (left != NULL)
+        *left = s.left;
+    if (in != NULL)
+        *in = s.left ? s.in : NULL;
+
+    /* write any leftover output and update the error code if needed */
+    if (err != 1 && s.next && s.outfun(s.outhow, s.out, s.next) && err == 0)
+        err = 1;
+    return err;
+}
+
+#ifdef TEST
+/* Example of how to use blast() */
+#include <stdio.h>
+#include <stdlib.h>
+
+#define CHUNK 16384
+
+local unsigned inf(void *how, unsigned char **buf)
+{
+    static unsigned char hold[CHUNK];
+
+    *buf = hold;
+    return fread(hold, 1, CHUNK, (FILE *)how);
+}
+
+local int outf(void *how, unsigned char *buf, unsigned len)
+{
+    return fwrite(buf, 1, len, (FILE *)how) != len;
+}
+
+/* Decompress a PKWare Compression Library stream from stdin to stdout */
+int main(void)
+{
+    int ret;
+    unsigned left;
+
+    /* decompress to stdout */
+    left = 0;
+    ret = blast(inf, stdin, outf, stdout, &left, NULL);
+    if (ret != 0)
+        fprintf(stderr, "blast error: %d\n", ret);
+
+    /* count any leftover bytes */
+    while (getchar() != EOF)
+        left++;
+    if (left)
+        fprintf(stderr, "blast warning: %u unused bytes of input\n", left);
+
+    /* return blast() error code */
+    return ret;
+}
+#endif
diff --git a/xs/src/png/zlib/contrib/blast/blast.h b/xs/src/png/zlib/contrib/blast/blast.h
new file mode 100644
index 000000000..6cf65eda1
--- /dev/null
+++ b/xs/src/png/zlib/contrib/blast/blast.h
@@ -0,0 +1,83 @@
+/* blast.h -- interface for blast.c
+  Copyright (C) 2003, 2012, 2013 Mark Adler
+  version 1.3, 24 Aug 2013
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+
+/*
+ * blast() decompresses the PKWare Data Compression Library (DCL) compressed
+ * format.  It provides the same functionality as the explode() function in
+ * that library.  (Note: PKWare overused the "implode" verb, and the format
+ * used by their library implode() function is completely different and
+ * incompatible with the implode compression method supported by PKZIP.)
+ *
+ * The binary mode for stdio functions should be used to assure that the
+ * compressed data is not corrupted when read or written.  For example:
+ * fopen(..., "rb") and fopen(..., "wb").
+ */
+
+
+typedef unsigned (*blast_in)(void *how, unsigned char **buf);
+typedef int (*blast_out)(void *how, unsigned char *buf, unsigned len);
+/* Definitions for input/output functions passed to blast().  See below for
+ * what the provided functions need to do.
+ */
+
+
+int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
+          unsigned *left, unsigned char **in);
+/* Decompress input to output using the provided infun() and outfun() calls.
+ * On success, the return value of blast() is zero.  If there is an error in
+ * the source data, i.e. it is not in the proper format, then a negative value
+ * is returned.  If there is not enough input available or there is not enough
+ * output space, then a positive error is returned.
+ *
+ * The input function is invoked: len = infun(how, &buf), where buf is set by
+ * infun() to point to the input buffer, and infun() returns the number of
+ * available bytes there.  If infun() returns zero, then blast() returns with
+ * an input error.  (blast() only asks for input if it needs it.)  inhow is for
+ * use by the application to pass an input descriptor to infun(), if desired.
+ *
+ * If left and in are not NULL and *left is not zero when blast() is called,
+ * then the *left bytes are *in are consumed for input before infun() is used.
+ *
+ * The output function is invoked: err = outfun(how, buf, len), where the bytes
+ * to be written are buf[0..len-1].  If err is not zero, then blast() returns
+ * with an output error.  outfun() is always called with len <= 4096.  outhow
+ * is for use by the application to pass an output descriptor to outfun(), if
+ * desired.
+ *
+ * If there is any unused input, *left is set to the number of bytes that were
+ * read and *in points to them.  Otherwise *left is set to zero and *in is set
+ * to NULL.  If left or in are NULL, then they are not set.
+ *
+ * The return codes are:
+ *
+ *   2:  ran out of input before completing decompression
+ *   1:  output error before completing decompression
+ *   0:  successful decompression
+ *  -1:  literal flag not zero or one
+ *  -2:  dictionary size not in 4..6
+ *  -3:  distance is too far back
+ *
+ * At the bottom of blast.c is an example program that uses blast() that can be
+ * compiled to produce a command-line decompression filter by defining TEST.
+ */
diff --git a/xs/src/png/zlib/contrib/blast/test.pk b/xs/src/png/zlib/contrib/blast/test.pk
new file mode 100644
index 000000000..be10b2bbb
--- /dev/null
+++ b/xs/src/png/zlib/contrib/blast/test.pk
diff --git a/xs/src/png/zlib/contrib/blast/test.txt b/xs/src/png/zlib/contrib/blast/test.txt
new file mode 100644
index 000000000..bfdf1c5dc
--- /dev/null
+++ b/xs/src/png/zlib/contrib/blast/test.txt
@@ -0,0 +1 @@
+AIAIAIAIAIAIA
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/delphi/ZLib.pas b/xs/src/png/zlib/contrib/delphi/ZLib.pas
new file mode 100644
index 000000000..060e19911
--- /dev/null
+++ b/xs/src/png/zlib/contrib/delphi/ZLib.pas
@@ -0,0 +1,557 @@
+{*******************************************************}
+{                                                       }
+{       Borland Delphi Supplemental Components          }
+{       ZLIB Data Compression Interface Unit            }
+{                                                       }
+{       Copyright (c) 1997,99 Borland Corporation       }
+{                                                       }
+{*******************************************************}
+
+{ Updated for zlib 1.2.x by Cosmin Truta <cosmint@cs.ubbcluj.ro> }
+
+unit ZLib;
+
+interface
+
+uses SysUtils, Classes;
+
+type
+  TAlloc = function (AppData: Pointer; Items, Size: Integer): Pointer; cdecl;
+  TFree = procedure (AppData, Block: Pointer); cdecl;
+
+  // Internal structure.  Ignore.
+  TZStreamRec = packed record
+    next_in: PChar;       // next input byte
+    avail_in: Integer;    // number of bytes available at next_in
+    total_in: Longint;    // total nb of input bytes read so far
+
+    next_out: PChar;      // next output byte should be put here
+    avail_out: Integer;   // remaining free space at next_out
+    total_out: Longint;   // total nb of bytes output so far
+
+    msg: PChar;           // last error message, NULL if no error
+    internal: Pointer;    // not visible by applications
+
+    zalloc: TAlloc;       // used to allocate the internal state
+    zfree: TFree;         // used to free the internal state
+    AppData: Pointer;     // private data object passed to zalloc and zfree
+
+    data_type: Integer;   // best guess about the data type: ascii or binary
+    adler: Longint;       // adler32 value of the uncompressed data
+    reserved: Longint;    // reserved for future use
+  end;
+
+  // Abstract ancestor class
+  TCustomZlibStream = class(TStream)
+  private
+    FStrm: TStream;
+    FStrmPos: Integer;
+    FOnProgress: TNotifyEvent;
+    FZRec: TZStreamRec;
+    FBuffer: array [Word] of Char;
+  protected
+    procedure Progress(Sender: TObject); dynamic;
+    property OnProgress: TNotifyEvent read FOnProgress write FOnProgress;
+    constructor Create(Strm: TStream);
+  end;
+
+{ TCompressionStream compresses data on the fly as data is written to it, and
+  stores the compressed data to another stream.
+
+  TCompressionStream is write-only and strictly sequential. Reading from the
+  stream will raise an exception. Using Seek to move the stream pointer
+  will raise an exception.
+
+  Output data is cached internally, written to the output stream only when
+  the internal output buffer is full.  All pending output data is flushed
+  when the stream is destroyed.
+
+  The Position property returns the number of uncompressed bytes of
+  data that have been written to the stream so far.
+
+  CompressionRate returns the on-the-fly percentage by which the original
+  data has been compressed:  (1 - (CompressedBytes / UncompressedBytes)) * 100
+  If raw data size = 100 and compressed data size = 25, the CompressionRate
+  is 75%
+
+  The OnProgress event is called each time the output buffer is filled and
+  written to the output stream.  This is useful for updating a progress
+  indicator when you are writing a large chunk of data to the compression
+  stream in a single call.}
+
+
+  TCompressionLevel = (clNone, clFastest, clDefault, clMax);
+
+  TCompressionStream = class(TCustomZlibStream)
+  private
+    function GetCompressionRate: Single;
+  public
+    constructor Create(CompressionLevel: TCompressionLevel; Dest: TStream);
+    destructor Destroy; override;
+    function Read(var Buffer; Count: Longint): Longint; override;
+    function Write(const Buffer; Count: Longint): Longint; override;
+    function Seek(Offset: Longint; Origin: Word): Longint; override;
+    property CompressionRate: Single read GetCompressionRate;
+    property OnProgress;
+  end;
+
+{ TDecompressionStream decompresses data on the fly as data is read from it.
+
+  Compressed data comes from a separate source stream.  TDecompressionStream
+  is read-only and unidirectional; you can seek forward in the stream, but not
+  backwards.  The special case of setting the stream position to zero is
+  allowed.  Seeking forward decompresses data until the requested position in
+  the uncompressed data has been reached.  Seeking backwards, seeking relative
+  to the end of the stream, requesting the size of the stream, and writing to
+  the stream will raise an exception.
+
+  The Position property returns the number of bytes of uncompressed data that
+  have been read from the stream so far.
+
+  The OnProgress event is called each time the internal input buffer of
+  compressed data is exhausted and the next block is read from the input stream.
+  This is useful for updating a progress indicator when you are reading a
+  large chunk of data from the decompression stream in a single call.}
+
+  TDecompressionStream = class(TCustomZlibStream)
+  public
+    constructor Create(Source: TStream);
+    destructor Destroy; override;
+    function Read(var Buffer; Count: Longint): Longint; override;
+    function Write(const Buffer; Count: Longint): Longint; override;
+    function Seek(Offset: Longint; Origin: Word): Longint; override;
+    property OnProgress;
+  end;
+
+
+
+{ CompressBuf compresses data, buffer to buffer, in one call.
+   In: InBuf = ptr to compressed data
+       InBytes = number of bytes in InBuf
+  Out: OutBuf = ptr to newly allocated buffer containing decompressed data
+       OutBytes = number of bytes in OutBuf   }
+procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
+                      out OutBuf: Pointer; out OutBytes: Integer);
+
+
+{ DecompressBuf decompresses data, buffer to buffer, in one call.
+   In: InBuf = ptr to compressed data
+       InBytes = number of bytes in InBuf
+       OutEstimate = zero, or est. size of the decompressed data
+  Out: OutBuf = ptr to newly allocated buffer containing decompressed data
+       OutBytes = number of bytes in OutBuf   }
+procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
+ OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer);
+
+{ DecompressToUserBuf decompresses data, buffer to buffer, in one call.
+   In: InBuf = ptr to compressed data
+       InBytes = number of bytes in InBuf
+  Out: OutBuf = ptr to user-allocated buffer to contain decompressed data
+       BufSize = number of bytes in OutBuf   }
+procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer;
+  const OutBuf: Pointer; BufSize: Integer);
+
+const
+  zlib_version = '1.2.11';
+
+type
+  EZlibError = class(Exception);
+  ECompressionError = class(EZlibError);
+  EDecompressionError = class(EZlibError);
+
+implementation
+
+uses ZLibConst;
+
+const
+  Z_NO_FLUSH      = 0;
+  Z_PARTIAL_FLUSH = 1;
+  Z_SYNC_FLUSH    = 2;
+  Z_FULL_FLUSH    = 3;
+  Z_FINISH        = 4;
+
+  Z_OK            = 0;
+  Z_STREAM_END    = 1;
+  Z_NEED_DICT     = 2;
+  Z_ERRNO         = (-1);
+  Z_STREAM_ERROR  = (-2);
+  Z_DATA_ERROR    = (-3);
+  Z_MEM_ERROR     = (-4);
+  Z_BUF_ERROR     = (-5);
+  Z_VERSION_ERROR = (-6);
+
+  Z_NO_COMPRESSION       =   0;
+  Z_BEST_SPEED           =   1;
+  Z_BEST_COMPRESSION     =   9;
+  Z_DEFAULT_COMPRESSION  = (-1);
+
+  Z_FILTERED            = 1;
+  Z_HUFFMAN_ONLY        = 2;
+  Z_RLE                 = 3;
+  Z_DEFAULT_STRATEGY    = 0;
+
+  Z_BINARY   = 0;
+  Z_ASCII    = 1;
+  Z_UNKNOWN  = 2;
+
+  Z_DEFLATED = 8;
+
+
+{$L adler32.obj}
+{$L compress.obj}
+{$L crc32.obj}
+{$L deflate.obj}
+{$L infback.obj}
+{$L inffast.obj}
+{$L inflate.obj}
+{$L inftrees.obj}
+{$L trees.obj}
+{$L uncompr.obj}
+{$L zutil.obj}
+
+procedure adler32; external;
+procedure compressBound; external;
+procedure crc32; external;
+procedure deflateInit2_; external;
+procedure deflateParams; external;
+
+function _malloc(Size: Integer): Pointer; cdecl;
+begin
+  Result := AllocMem(Size);
+end;
+
+procedure _free(Block: Pointer); cdecl;
+begin
+  FreeMem(Block);
+end;
+
+procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl;
+begin
+  FillChar(P^, count, B);
+end;
+
+procedure _memcpy(dest, source: Pointer; count: Integer); cdecl;
+begin
+  Move(source^, dest^, count);
+end;
+
+
+
+// deflate compresses data
+function deflateInit_(var strm: TZStreamRec; level: Integer; version: PChar;
+  recsize: Integer): Integer; external;
+function deflate(var strm: TZStreamRec; flush: Integer): Integer; external;
+function deflateEnd(var strm: TZStreamRec): Integer; external;
+
+// inflate decompresses data
+function inflateInit_(var strm: TZStreamRec; version: PChar;
+  recsize: Integer): Integer; external;
+function inflate(var strm: TZStreamRec; flush: Integer): Integer; external;
+function inflateEnd(var strm: TZStreamRec): Integer; external;
+function inflateReset(var strm: TZStreamRec): Integer; external;
+
+
+function zlibAllocMem(AppData: Pointer; Items, Size: Integer): Pointer; cdecl;
+begin
+//  GetMem(Result, Items*Size);
+  Result := AllocMem(Items * Size);
+end;
+
+procedure zlibFreeMem(AppData, Block: Pointer); cdecl;
+begin
+  FreeMem(Block);
+end;
+
+{function zlibCheck(code: Integer): Integer;
+begin
+  Result := code;
+  if code < 0 then
+    raise EZlibError.Create('error');    //!!
+end;}
+
+function CCheck(code: Integer): Integer;
+begin
+  Result := code;
+  if code < 0 then
+    raise ECompressionError.Create('error'); //!!
+end;
+
+function DCheck(code: Integer): Integer;
+begin
+  Result := code;
+  if code < 0 then
+    raise EDecompressionError.Create('error');  //!!
+end;
+
+procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
+                      out OutBuf: Pointer; out OutBytes: Integer);
+var
+  strm: TZStreamRec;
+  P: Pointer;
+begin
+  FillChar(strm, sizeof(strm), 0);
+  strm.zalloc := zlibAllocMem;
+  strm.zfree := zlibFreeMem;
+  OutBytes := ((InBytes + (InBytes div 10) + 12) + 255) and not 255;
+  GetMem(OutBuf, OutBytes);
+  try
+    strm.next_in := InBuf;
+    strm.avail_in := InBytes;
+    strm.next_out := OutBuf;
+    strm.avail_out := OutBytes;
+    CCheck(deflateInit_(strm, Z_BEST_COMPRESSION, zlib_version, sizeof(strm)));
+    try
+      while CCheck(deflate(strm, Z_FINISH)) <> Z_STREAM_END do
+      begin
+        P := OutBuf;
+        Inc(OutBytes, 256);
+        ReallocMem(OutBuf, OutBytes);
+        strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P)));
+        strm.avail_out := 256;
+      end;
+    finally
+      CCheck(deflateEnd(strm));
+    end;
+    ReallocMem(OutBuf, strm.total_out);
+    OutBytes := strm.total_out;
+  except
+    FreeMem(OutBuf);
+    raise
+  end;
+end;
+
+
+procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
+  OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer);
+var
+  strm: TZStreamRec;
+  P: Pointer;
+  BufInc: Integer;
+begin
+  FillChar(strm, sizeof(strm), 0);
+  strm.zalloc := zlibAllocMem;
+  strm.zfree := zlibFreeMem;
+  BufInc := (InBytes + 255) and not 255;
+  if OutEstimate = 0 then
+    OutBytes := BufInc
+  else
+    OutBytes := OutEstimate;
+  GetMem(OutBuf, OutBytes);
+  try
+    strm.next_in := InBuf;
+    strm.avail_in := InBytes;
+    strm.next_out := OutBuf;
+    strm.avail_out := OutBytes;
+    DCheck(inflateInit_(strm, zlib_version, sizeof(strm)));
+    try
+      while DCheck(inflate(strm, Z_NO_FLUSH)) <> Z_STREAM_END do
+      begin
+        P := OutBuf;
+        Inc(OutBytes, BufInc);
+        ReallocMem(OutBuf, OutBytes);
+        strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P)));
+        strm.avail_out := BufInc;
+      end;
+    finally
+      DCheck(inflateEnd(strm));
+    end;
+    ReallocMem(OutBuf, strm.total_out);
+    OutBytes := strm.total_out;
+  except
+    FreeMem(OutBuf);
+    raise
+  end;
+end;
+
+procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer;
+  const OutBuf: Pointer; BufSize: Integer);
+var
+  strm: TZStreamRec;
+begin
+  FillChar(strm, sizeof(strm), 0);
+  strm.zalloc := zlibAllocMem;
+  strm.zfree := zlibFreeMem;
+  strm.next_in := InBuf;
+  strm.avail_in := InBytes;
+  strm.next_out := OutBuf;
+  strm.avail_out := BufSize;
+  DCheck(inflateInit_(strm, zlib_version, sizeof(strm)));
+  try
+    if DCheck(inflate(strm, Z_FINISH)) <> Z_STREAM_END then
+      raise EZlibError.CreateRes(@sTargetBufferTooSmall);
+  finally
+    DCheck(inflateEnd(strm));
+  end;
+end;
+
+// TCustomZlibStream
+
+constructor TCustomZLibStream.Create(Strm: TStream);
+begin
+  inherited Create;
+  FStrm := Strm;
+  FStrmPos := Strm.Position;
+  FZRec.zalloc := zlibAllocMem;
+  FZRec.zfree := zlibFreeMem;
+end;
+
+procedure TCustomZLibStream.Progress(Sender: TObject);
+begin
+  if Assigned(FOnProgress) then FOnProgress(Sender);
+end;
+
+
+// TCompressionStream
+
+constructor TCompressionStream.Create(CompressionLevel: TCompressionLevel;
+  Dest: TStream);
+const
+  Levels: array [TCompressionLevel] of ShortInt =
+    (Z_NO_COMPRESSION, Z_BEST_SPEED, Z_DEFAULT_COMPRESSION, Z_BEST_COMPRESSION);
+begin
+  inherited Create(Dest);
+  FZRec.next_out := FBuffer;
+  FZRec.avail_out := sizeof(FBuffer);
+  CCheck(deflateInit_(FZRec, Levels[CompressionLevel], zlib_version, sizeof(FZRec)));
+end;
+
+destructor TCompressionStream.Destroy;
+begin
+  FZRec.next_in := nil;
+  FZRec.avail_in := 0;
+  try
+    if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
+    while (CCheck(deflate(FZRec, Z_FINISH)) <> Z_STREAM_END)
+      and (FZRec.avail_out = 0) do
+    begin
+      FStrm.WriteBuffer(FBuffer, sizeof(FBuffer));
+      FZRec.next_out := FBuffer;
+      FZRec.avail_out := sizeof(FBuffer);
+    end;
+    if FZRec.avail_out < sizeof(FBuffer) then
+      FStrm.WriteBuffer(FBuffer, sizeof(FBuffer) - FZRec.avail_out);
+  finally
+    deflateEnd(FZRec);
+  end;
+  inherited Destroy;
+end;
+
+function TCompressionStream.Read(var Buffer; Count: Longint): Longint;
+begin
+  raise ECompressionError.CreateRes(@sInvalidStreamOp);
+end;
+
+function TCompressionStream.Write(const Buffer; Count: Longint): Longint;
+begin
+  FZRec.next_in := @Buffer;
+  FZRec.avail_in := Count;
+  if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
+  while (FZRec.avail_in > 0) do
+  begin
+    CCheck(deflate(FZRec, 0));
+    if FZRec.avail_out = 0 then
+    begin
+      FStrm.WriteBuffer(FBuffer, sizeof(FBuffer));
+      FZRec.next_out := FBuffer;
+      FZRec.avail_out := sizeof(FBuffer);
+      FStrmPos := FStrm.Position;
+      Progress(Self);
+    end;
+  end;
+  Result := Count;
+end;
+
+function TCompressionStream.Seek(Offset: Longint; Origin: Word): Longint;
+begin
+  if (Offset = 0) and (Origin = soFromCurrent) then
+    Result := FZRec.total_in
+  else
+    raise ECompressionError.CreateRes(@sInvalidStreamOp);
+end;
+
+function TCompressionStream.GetCompressionRate: Single;
+begin
+  if FZRec.total_in = 0 then
+    Result := 0
+  else
+    Result := (1.0 - (FZRec.total_out / FZRec.total_in)) * 100.0;
+end;
+
+
+// TDecompressionStream
+
+constructor TDecompressionStream.Create(Source: TStream);
+begin
+  inherited Create(Source);
+  FZRec.next_in := FBuffer;
+  FZRec.avail_in := 0;
+  DCheck(inflateInit_(FZRec, zlib_version, sizeof(FZRec)));
+end;
+
+destructor TDecompressionStream.Destroy;
+begin
+  FStrm.Seek(-FZRec.avail_in, 1);
+  inflateEnd(FZRec);
+  inherited Destroy;
+end;
+
+function TDecompressionStream.Read(var Buffer; Count: Longint): Longint;
+begin
+  FZRec.next_out := @Buffer;
+  FZRec.avail_out := Count;
+  if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
+  while (FZRec.avail_out > 0) do
+  begin
+    if FZRec.avail_in = 0 then
+    begin
+      FZRec.avail_in := FStrm.Read(FBuffer, sizeof(FBuffer));
+      if FZRec.avail_in = 0 then
+      begin
+        Result := Count - FZRec.avail_out;
+        Exit;
+      end;
+      FZRec.next_in := FBuffer;
+      FStrmPos := FStrm.Position;
+      Progress(Self);
+    end;
+    CCheck(inflate(FZRec, 0));
+  end;
+  Result := Count;
+end;
+
+function TDecompressionStream.Write(const Buffer; Count: Longint): Longint;
+begin
+  raise EDecompressionError.CreateRes(@sInvalidStreamOp);
+end;
+
+function TDecompressionStream.Seek(Offset: Longint; Origin: Word): Longint;
+var
+  I: Integer;
+  Buf: array [0..4095] of Char;
+begin
+  if (Offset = 0) and (Origin = soFromBeginning) then
+  begin
+    DCheck(inflateReset(FZRec));
+    FZRec.next_in := FBuffer;
+    FZRec.avail_in := 0;
+    FStrm.Position := 0;
+    FStrmPos := 0;
+  end
+  else if ( (Offset >= 0) and (Origin = soFromCurrent)) or
+          ( ((Offset - FZRec.total_out) > 0) and (Origin = soFromBeginning)) then
+  begin
+    if Origin = soFromBeginning then Dec(Offset, FZRec.total_out);
+    if Offset > 0 then
+    begin
+      for I := 1 to Offset div sizeof(Buf) do
+        ReadBuffer(Buf, sizeof(Buf));
+      ReadBuffer(Buf, Offset mod sizeof(Buf));
+    end;
+  end
+  else
+    raise EDecompressionError.CreateRes(@sInvalidStreamOp);
+  Result := FZRec.total_out;
+end;
+
+
+end.
diff --git a/xs/src/png/zlib/contrib/delphi/ZLibConst.pas b/xs/src/png/zlib/contrib/delphi/ZLibConst.pas
new file mode 100644
index 000000000..cdfe13671
--- /dev/null
+++ b/xs/src/png/zlib/contrib/delphi/ZLibConst.pas
@@ -0,0 +1,11 @@
+unit ZLibConst;
+
+interface
+
+resourcestring
+  sTargetBufferTooSmall = 'ZLib error: target buffer may be too small';
+  sInvalidStreamOp = 'Invalid stream operation';
+
+implementation
+
+end.
diff --git a/xs/src/png/zlib/contrib/delphi/readme.txt b/xs/src/png/zlib/contrib/delphi/readme.txt
new file mode 100644
index 000000000..2dc9a8bba
--- /dev/null
+++ b/xs/src/png/zlib/contrib/delphi/readme.txt
@@ -0,0 +1,76 @@
+
+Overview
+========
+
+This directory contains an update to the ZLib interface unit,
+distributed by Borland as a Delphi supplemental component.
+
+The original ZLib unit is Copyright (c) 1997,99 Borland Corp.,
+and is based on zlib version 1.0.4.  There are a series of bugs
+and security problems associated with that old zlib version, and
+we recommend the users to update their ZLib unit.
+
+
+Summary of modifications
+========================
+
+- Improved makefile, adapted to zlib version 1.2.1.
+
+- Some field types from TZStreamRec are changed from Integer to
+  Longint, for consistency with the zlib.h header, and for 64-bit
+  readiness.
+
+- The zlib_version constant is updated.
+
+- The new Z_RLE strategy has its corresponding symbolic constant.
+
+- The allocation and deallocation functions and function types
+  (TAlloc, TFree, zlibAllocMem and zlibFreeMem) are now cdecl,
+  and _malloc and _free are added as C RTL stubs.  As a result,
+  the original C sources of zlib can be compiled out of the box,
+  and linked to the ZLib unit.
+
+
+Suggestions for improvements
+============================
+
+Currently, the ZLib unit provides only a limited wrapper around
+the zlib library, and much of the original zlib functionality is
+missing.  Handling compressed file formats like ZIP/GZIP or PNG
+cannot be implemented without having this functionality.
+Applications that handle these formats are either using their own,
+duplicated code, or not using the ZLib unit at all.
+
+Here are a few suggestions:
+
+- Checksum class wrappers around adler32() and crc32(), similar
+  to the Java classes that implement the java.util.zip.Checksum
+  interface.
+
+- The ability to read and write raw deflate streams, without the
+  zlib stream header and trailer.  Raw deflate streams are used
+  in the ZIP file format.
+
+- The ability to read and write gzip streams, used in the GZIP
+  file format, and normally produced by the gzip program.
+
+- The ability to select a different compression strategy, useful
+  to PNG and MNG image compression, and to multimedia compression
+  in general.  Besides the compression level
+
+    TCompressionLevel = (clNone, clFastest, clDefault, clMax);
+
+  which, in fact, could have used the 'z' prefix and avoided
+  TColor-like symbols
+
+    TCompressionLevel = (zcNone, zcFastest, zcDefault, zcMax);
+
+  there could be a compression strategy
+
+    TCompressionStrategy = (zsDefault, zsFiltered, zsHuffmanOnly, zsRle);
+
+- ZIP and GZIP stream handling via TStreams.
+
+
+--
+Cosmin Truta <cosmint@cs.ubbcluj.ro>
diff --git a/xs/src/png/zlib/contrib/delphi/zlibd32.mak b/xs/src/png/zlib/contrib/delphi/zlibd32.mak
new file mode 100644
index 000000000..9bb00b7cc
--- /dev/null
+++ b/xs/src/png/zlib/contrib/delphi/zlibd32.mak
@@ -0,0 +1,99 @@
+# Makefile for zlib
+# For use with Delphi and C++ Builder under Win32
+# Updated for zlib 1.2.x by Cosmin Truta
+
+# ------------ Borland C++ ------------
+
+# This project uses the Delphi (fastcall/register) calling convention:
+LOC = -DZEXPORT=__fastcall -DZEXPORTVA=__cdecl
+
+CC = bcc32
+LD = bcc32
+AR = tlib
+# do not use "-pr" in CFLAGS
+CFLAGS = -a -d -k- -O2 $(LOC)
+LDFLAGS =
+
+
+# variables
+ZLIB_LIB = zlib.lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# For the sake of the old Borland make,
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+
+
+# testing
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+
+# cleanup
+clean:
+	-del *.obj
+	-del *.exe
+	-del *.lib
+	-del *.tds
+	-del zlib.bak
+	-del foo.gz
+
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib.build b/xs/src/png/zlib/contrib/dotzlib/DotZLib.build
new file mode 100644
index 000000000..e69630cec
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib.build
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<project name="DotZLib" default="build" basedir="./DotZLib">
+	<description>A .Net wrapper library around ZLib1.dll</description>
+
+	<property name="nunit.location" value="c:/program files/NUnit V2.1/bin" />
+	<property name="build.root" value="bin" />
+
+	<property name="debug" value="true" />
+	<property name="nunit" value="true" />
+
+	<property name="build.folder" value="${build.root}/debug/" if="${debug}" />
+	<property name="build.folder" value="${build.root}/release/" unless="${debug}" />
+
+	<target name="clean" description="Remove all generated files">
+		<delete dir="${build.root}" failonerror="false" />
+	</target>
+
+	<target name="build" description="compiles the source code">
+
+		<mkdir dir="${build.folder}" />
+		<csc target="library" output="${build.folder}DotZLib.dll" debug="${debug}">
+			<references basedir="${nunit.location}">
+				<includes if="${nunit}" name="nunit.framework.dll" />
+			</references>
+			<sources>
+				<includes name="*.cs" />
+				<excludes name="UnitTests.cs" unless="${nunit}" />
+			</sources>
+			<arg value="/d:nunit" if="${nunit}" />
+		</csc>
+	</target>
+
+</project>
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib.chm b/xs/src/png/zlib/contrib/dotzlib/DotZLib.chm
new file mode 100644
index 000000000..f214a444a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib.chm
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib.sln b/xs/src/png/zlib/contrib/dotzlib/DotZLib.sln
new file mode 100644
index 000000000..5d533d6bc
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib.sln
@@ -0,0 +1,21 @@
+Microsoft Visual Studio Solution File, Format Version 8.00
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DotZLib", "DotZLib\DotZLib.csproj", "{BB1EE0B1-1808-46CB-B786-949D91117FC5}"
+	ProjectSection(ProjectDependencies) = postProject
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfiguration) = preSolution
+		Debug = Debug
+		Release = Release
+	EndGlobalSection
+	GlobalSection(ProjectConfiguration) = postSolution
+		{BB1EE0B1-1808-46CB-B786-949D91117FC5}.Debug.ActiveCfg = Debug|.NET
+		{BB1EE0B1-1808-46CB-B786-949D91117FC5}.Debug.Build.0 = Debug|.NET
+		{BB1EE0B1-1808-46CB-B786-949D91117FC5}.Release.ActiveCfg = Release|.NET
+		{BB1EE0B1-1808-46CB-B786-949D91117FC5}.Release.Build.0 = Release|.NET
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+	EndGlobalSection
+	GlobalSection(ExtensibilityAddIns) = postSolution
+	EndGlobalSection
+EndGlobal
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/AssemblyInfo.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/AssemblyInfo.cs
new file mode 100644
index 000000000..724c5347f
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/AssemblyInfo.cs
@@ -0,0 +1,58 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+
+//
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+//
+[assembly: AssemblyTitle("DotZLib")]
+[assembly: AssemblyDescription(".Net bindings for ZLib compression dll 1.2.x")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("Henrik Ravn")]
+[assembly: AssemblyProduct("")]
+[assembly: AssemblyCopyright("(c) 2004 by Henrik Ravn")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+//
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Revision and Build Numbers
+// by using the '*' as shown below:
+
+[assembly: AssemblyVersion("1.0.*")]
+
+//
+// In order to sign your assembly you must specify a key to use. Refer to the
+// Microsoft .NET Framework documentation for more information on assembly signing.
+//
+// Use the attributes below to control which key is used for signing.
+//
+// Notes:
+//   (*) If no key is specified, the assembly is not signed.
+//   (*) KeyName refers to a key that has been installed in the Crypto Service
+//       Provider (CSP) on your machine. KeyFile refers to a file which contains
+//       a key.
+//   (*) If the KeyFile and the KeyName values are both specified, the
+//       following processing occurs:
+//       (1) If the KeyName can be found in the CSP, that key is used.
+//       (2) If the KeyName does not exist and the KeyFile does exist, the key
+//           in the KeyFile is installed into the CSP and used.
+//   (*) In order to create a KeyFile, you can use the sn.exe (Strong Name) utility.
+//       When specifying the KeyFile, the location of the KeyFile should be
+//       relative to the project output directory which is
+//       %Project Directory%\obj\<configuration>. For example, if your KeyFile is
+//       located in the project directory, you would specify the AssemblyKeyFile
+//       attribute as [assembly: AssemblyKeyFile("..\\..\\mykey.snk")]
+//   (*) Delay Signing is an advanced option - see the Microsoft .NET Framework
+//       documentation for more information on this.
+//
+[assembly: AssemblyDelaySign(false)]
+[assembly: AssemblyKeyFile("")]
+[assembly: AssemblyKeyName("")]
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs
new file mode 100644
index 000000000..b110dae6a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs
@@ -0,0 +1,202 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+
+
+namespace DotZLib
+{
+    #region ChecksumGeneratorBase
+    /// <summary>
+    /// Implements the common functionality needed for all <see cref="ChecksumGenerator"/>s
+    /// </summary>
+    /// <example></example>
+    public abstract class ChecksumGeneratorBase : ChecksumGenerator
+    {
+        /// <summary>
+        /// The value of the current checksum
+        /// </summary>
+        protected uint _current;
+
+        /// <summary>
+        /// Initializes a new instance of the checksum generator base - the current checksum is
+        /// set to zero
+        /// </summary>
+        public ChecksumGeneratorBase()
+        {
+            _current = 0;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the checksum generator basewith a specified value
+        /// </summary>
+        /// <param name="initialValue">The value to set the current checksum to</param>
+        public ChecksumGeneratorBase(uint initialValue)
+        {
+            _current = initialValue;
+        }
+
+        /// <summary>
+        /// Resets the current checksum to zero
+        /// </summary>
+        public void Reset() { _current = 0; }
+
+        /// <summary>
+        /// Gets the current checksum value
+        /// </summary>
+        public uint Value { get { return _current; } }
+
+        /// <summary>
+        /// Updates the current checksum with part of an array of bytes
+        /// </summary>
+        /// <param name="data">The data to update the checksum with</param>
+        /// <param name="offset">Where in <c>data</c> to start updating</param>
+        /// <param name="count">The number of bytes from <c>data</c> to use</param>
+        /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+        /// <exception cref="NullReferenceException"><c>data</c> is a null reference</exception>
+        /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+        /// <remarks>All the other <c>Update</c> methods are implmeneted in terms of this one.
+        /// This is therefore the only method a derived class has to implement</remarks>
+        public abstract void Update(byte[] data, int offset, int count);
+
+        /// <summary>
+        /// Updates the current checksum with an array of bytes.
+        /// </summary>
+        /// <param name="data">The data to update the checksum with</param>
+        public void Update(byte[] data)
+        {
+            Update(data, 0, data.Length);
+        }
+
+        /// <summary>
+        /// Updates the current checksum with the data from a string
+        /// </summary>
+        /// <param name="data">The string to update the checksum with</param>
+        /// <remarks>The characters in the string are converted by the UTF-8 encoding</remarks>
+        public void Update(string data)
+        {
+			Update(Encoding.UTF8.GetBytes(data));
+        }
+
+        /// <summary>
+        /// Updates the current checksum with the data from a string, using a specific encoding
+        /// </summary>
+        /// <param name="data">The string to update the checksum with</param>
+        /// <param name="encoding">The encoding to use</param>
+        public void Update(string data, Encoding encoding)
+        {
+            Update(encoding.GetBytes(data));
+        }
+
+    }
+    #endregion
+
+    #region CRC32
+    /// <summary>
+    /// Implements a CRC32 checksum generator
+    /// </summary>
+    public sealed class CRC32Checksum : ChecksumGeneratorBase
+    {
+        #region DLL imports
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern uint crc32(uint crc, int data, uint length);
+
+        #endregion
+
+        /// <summary>
+        /// Initializes a new instance of the CRC32 checksum generator
+        /// </summary>
+        public CRC32Checksum() : base() {}
+
+        /// <summary>
+        /// Initializes a new instance of the CRC32 checksum generator with a specified value
+        /// </summary>
+        /// <param name="initialValue">The value to set the current checksum to</param>
+        public CRC32Checksum(uint initialValue) : base(initialValue) {}
+
+        /// <summary>
+        /// Updates the current checksum with part of an array of bytes
+        /// </summary>
+        /// <param name="data">The data to update the checksum with</param>
+        /// <param name="offset">Where in <c>data</c> to start updating</param>
+        /// <param name="count">The number of bytes from <c>data</c> to use</param>
+        /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+        /// <exception cref="NullReferenceException"><c>data</c> is a null reference</exception>
+        /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+        public override void Update(byte[] data, int offset, int count)
+        {
+            if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+            if ((offset+count) > data.Length) throw new ArgumentException();
+            GCHandle hData = GCHandle.Alloc(data, GCHandleType.Pinned);
+            try
+            {
+                _current = crc32(_current, hData.AddrOfPinnedObject().ToInt32()+offset, (uint)count);
+            }
+            finally
+            {
+                hData.Free();
+            }
+        }
+
+    }
+    #endregion
+
+    #region Adler
+    /// <summary>
+    /// Implements a checksum generator that computes the Adler checksum on data
+    /// </summary>
+    public sealed class AdlerChecksum : ChecksumGeneratorBase
+    {
+        #region DLL imports
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern uint adler32(uint adler, int data, uint length);
+
+        #endregion
+
+        /// <summary>
+        /// Initializes a new instance of the Adler checksum generator
+        /// </summary>
+        public AdlerChecksum() : base() {}
+
+        /// <summary>
+        /// Initializes a new instance of the Adler checksum generator with a specified value
+        /// </summary>
+        /// <param name="initialValue">The value to set the current checksum to</param>
+        public AdlerChecksum(uint initialValue) : base(initialValue) {}
+
+        /// <summary>
+        /// Updates the current checksum with part of an array of bytes
+        /// </summary>
+        /// <param name="data">The data to update the checksum with</param>
+        /// <param name="offset">Where in <c>data</c> to start updating</param>
+        /// <param name="count">The number of bytes from <c>data</c> to use</param>
+        /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+        /// <exception cref="NullReferenceException"><c>data</c> is a null reference</exception>
+        /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+        public override void Update(byte[] data, int offset, int count)
+        {
+            if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+            if ((offset+count) > data.Length) throw new ArgumentException();
+            GCHandle hData = GCHandle.Alloc(data, GCHandleType.Pinned);
+            try
+            {
+                _current = adler32(_current, hData.AddrOfPinnedObject().ToInt32()+offset, (uint)count);
+            }
+            finally
+            {
+                hData.Free();
+            }
+        }
+
+    }
+    #endregion
+
+}
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs
new file mode 100644
index 000000000..9c8d60195
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/CircularBuffer.cs
@@ -0,0 +1,83 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Diagnostics;
+
+namespace DotZLib
+{
+
+	/// <summary>
+	/// This class implements a circular buffer
+	/// </summary>
+	internal class CircularBuffer
+	{
+        #region Private data
+        private int _capacity;
+        private int _head;
+        private int _tail;
+        private int _size;
+        private byte[] _buffer;
+        #endregion
+
+        public CircularBuffer(int capacity)
+        {
+            Debug.Assert( capacity > 0 );
+            _buffer = new byte[capacity];
+            _capacity = capacity;
+            _head = 0;
+            _tail = 0;
+            _size = 0;
+        }
+
+        public int Size { get { return _size; } }
+
+        public int Put(byte[] source, int offset, int count)
+        {
+            Debug.Assert( count > 0 );
+            int trueCount = Math.Min(count, _capacity - Size);
+            for (int i = 0; i < trueCount; ++i)
+                _buffer[(_tail+i) % _capacity] = source[offset+i];
+            _tail += trueCount;
+            _tail %= _capacity;
+            _size += trueCount;
+            return trueCount;
+        }
+
+        public bool Put(byte b)
+        {
+            if (Size == _capacity) // no room
+                return false;
+            _buffer[_tail++] = b;
+            _tail %= _capacity;
+            ++_size;
+            return true;
+        }
+
+        public int Get(byte[] destination, int offset, int count)
+        {
+            int trueCount = Math.Min(count,Size);
+            for (int i = 0; i < trueCount; ++i)
+                destination[offset + i] = _buffer[(_head+i) % _capacity];
+            _head += trueCount;
+            _head %= _capacity;
+            _size -= trueCount;
+            return trueCount;
+        }
+
+        public int Get()
+        {
+            if (Size == 0)
+                return -1;
+
+            int result = (int)_buffer[_head++ % _capacity];
+            --_size;
+            return result;
+        }
+
+    }
+}
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/CodecBase.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/CodecBase.cs
new file mode 100644
index 000000000..b0eb78a02
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/CodecBase.cs
@@ -0,0 +1,198 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Runtime.InteropServices;
+
+namespace DotZLib
+{
+	/// <summary>
+	/// Implements the common functionality needed for all <see cref="Codec"/>s
+	/// </summary>
+	public abstract class CodecBase : Codec, IDisposable
+	{
+
+        #region Data members
+
+        /// <summary>
+        /// Instance of the internal zlib buffer structure that is
+        /// passed to all functions in the zlib dll
+        /// </summary>
+        internal ZStream _ztream = new ZStream();
+
+        /// <summary>
+        /// True if the object instance has been disposed, false otherwise
+        /// </summary>
+        protected bool _isDisposed = false;
+
+        /// <summary>
+        /// The size of the internal buffers
+        /// </summary>
+        protected const int kBufferSize = 16384;
+
+        private byte[] _outBuffer = new byte[kBufferSize];
+        private byte[] _inBuffer = new byte[kBufferSize];
+
+        private GCHandle _hInput;
+        private GCHandle _hOutput;
+
+        private uint _checksum = 0;
+
+        #endregion
+
+        /// <summary>
+        /// Initializes a new instance of the <c>CodeBase</c> class.
+        /// </summary>
+		public CodecBase()
+		{
+            try
+            {
+                _hInput = GCHandle.Alloc(_inBuffer, GCHandleType.Pinned);
+                _hOutput = GCHandle.Alloc(_outBuffer, GCHandleType.Pinned);
+            }
+            catch (Exception)
+            {
+                CleanUp(false);
+                throw;
+            }
+        }
+
+
+        #region Codec Members
+
+        /// <summary>
+        /// Occurs when more processed data are available.
+        /// </summary>
+        public event DataAvailableHandler DataAvailable;
+
+        /// <summary>
+        /// Fires the <see cref="DataAvailable"/> event
+        /// </summary>
+        protected void OnDataAvailable()
+        {
+            if (_ztream.total_out > 0)
+            {
+                if (DataAvailable != null)
+                    DataAvailable( _outBuffer, 0, (int)_ztream.total_out);
+                resetOutput();
+            }
+        }
+
+        /// <summary>
+        /// Adds more data to the codec to be processed.
+        /// </summary>
+        /// <param name="data">Byte array containing the data to be added to the codec</param>
+        /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
+        public void Add(byte[] data)
+        {
+            Add(data,0,data.Length);
+        }
+
+        /// <summary>
+        /// Adds more data to the codec to be processed.
+        /// </summary>
+        /// <param name="data">Byte array containing the data to be added to the codec</param>
+        /// <param name="offset">The index of the first byte to add from <c>data</c></param>
+        /// <param name="count">The number of bytes to add</param>
+        /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
+        /// <remarks>This must be implemented by a derived class</remarks>
+        public abstract void Add(byte[] data, int offset, int count);
+
+        /// <summary>
+        /// Finishes up any pending data that needs to be processed and handled.
+        /// </summary>
+        /// <remarks>This must be implemented by a derived class</remarks>
+        public abstract void Finish();
+
+        /// <summary>
+        /// Gets the checksum of the data that has been added so far
+        /// </summary>
+        public uint Checksum { get { return _checksum; } }
+
+        #endregion
+
+        #region Destructor & IDisposable stuff
+
+        /// <summary>
+        /// Destroys this instance
+        /// </summary>
+        ~CodecBase()
+        {
+            CleanUp(false);
+        }
+
+        /// <summary>
+        /// Releases any unmanaged resources and calls the <see cref="CleanUp()"/> method of the derived class
+        /// </summary>
+        public void Dispose()
+        {
+            CleanUp(true);
+        }
+
+        /// <summary>
+        /// Performs any codec specific cleanup
+        /// </summary>
+        /// <remarks>This must be implemented by a derived class</remarks>
+        protected abstract void CleanUp();
+
+        // performs the release of the handles and calls the dereived CleanUp()
+        private void CleanUp(bool isDisposing)
+        {
+            if (!_isDisposed)
+            {
+                CleanUp();
+                if (_hInput.IsAllocated)
+                    _hInput.Free();
+                if (_hOutput.IsAllocated)
+                    _hOutput.Free();
+
+                _isDisposed = true;
+            }
+        }
+
+
+        #endregion
+
+        #region Helper methods
+
+        /// <summary>
+        /// Copies a number of bytes to the internal codec buffer - ready for proccesing
+        /// </summary>
+        /// <param name="data">The byte array that contains the data to copy</param>
+        /// <param name="startIndex">The index of the first byte to copy</param>
+        /// <param name="count">The number of bytes to copy from <c>data</c></param>
+        protected void copyInput(byte[] data, int startIndex, int count)
+        {
+            Array.Copy(data, startIndex, _inBuffer,0, count);
+            _ztream.next_in = _hInput.AddrOfPinnedObject();
+            _ztream.total_in = 0;
+            _ztream.avail_in = (uint)count;
+
+        }
+
+        /// <summary>
+        /// Resets the internal output buffers to a known state - ready for processing
+        /// </summary>
+        protected void resetOutput()
+        {
+            _ztream.total_out = 0;
+            _ztream.avail_out = kBufferSize;
+            _ztream.next_out = _hOutput.AddrOfPinnedObject();
+        }
+
+        /// <summary>
+        /// Updates the running checksum property
+        /// </summary>
+        /// <param name="newSum">The new checksum value</param>
+        protected void setChecksum(uint newSum)
+        {
+            _checksum = newSum;
+        }
+        #endregion
+
+    }
+}
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/Deflater.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/Deflater.cs
new file mode 100644
index 000000000..9039f41f6
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/Deflater.cs
@@ -0,0 +1,106 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace DotZLib
+{
+
+    /// <summary>
+    /// Implements a data compressor, using the deflate algorithm in the ZLib dll
+    /// </summary>
+	public sealed class Deflater : CodecBase
+	{
+        #region Dll imports
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl, CharSet=CharSet.Ansi)]
+        private static extern int deflateInit_(ref ZStream sz, int level, string vs, int size);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int deflate(ref ZStream sz, int flush);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int deflateReset(ref ZStream sz);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int deflateEnd(ref ZStream sz);
+        #endregion
+
+        /// <summary>
+        /// Constructs an new instance of the <c>Deflater</c>
+        /// </summary>
+        /// <param name="level">The compression level to use for this <c>Deflater</c></param>
+		public Deflater(CompressLevel level) : base()
+		{
+            int retval = deflateInit_(ref _ztream, (int)level, Info.Version, Marshal.SizeOf(_ztream));
+            if (retval != 0)
+                throw new ZLibException(retval, "Could not initialize deflater");
+
+            resetOutput();
+		}
+
+        /// <summary>
+        /// Adds more data to the codec to be processed.
+        /// </summary>
+        /// <param name="data">Byte array containing the data to be added to the codec</param>
+        /// <param name="offset">The index of the first byte to add from <c>data</c></param>
+        /// <param name="count">The number of bytes to add</param>
+        /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
+        public override void Add(byte[] data, int offset, int count)
+        {
+            if (data == null) throw new ArgumentNullException();
+            if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+            if ((offset+count) > data.Length) throw new ArgumentException();
+
+            int total = count;
+            int inputIndex = offset;
+            int err = 0;
+
+            while (err >= 0 && inputIndex < total)
+            {
+                copyInput(data, inputIndex, Math.Min(total - inputIndex, kBufferSize));
+                while (err >= 0 && _ztream.avail_in > 0)
+                {
+                    err = deflate(ref _ztream, (int)FlushTypes.None);
+                    if (err == 0)
+                        while (_ztream.avail_out == 0)
+                        {
+                            OnDataAvailable();
+                            err = deflate(ref _ztream, (int)FlushTypes.None);
+                        }
+                    inputIndex += (int)_ztream.total_in;
+                }
+            }
+            setChecksum( _ztream.adler );
+        }
+
+
+        /// <summary>
+        /// Finishes up any pending data that needs to be processed and handled.
+        /// </summary>
+        public override void Finish()
+        {
+            int err;
+            do
+            {
+                err = deflate(ref _ztream, (int)FlushTypes.Finish);
+                OnDataAvailable();
+            }
+            while (err == 0);
+            setChecksum( _ztream.adler );
+            deflateReset(ref _ztream);
+            resetOutput();
+        }
+
+        /// <summary>
+        /// Closes the internal zlib deflate stream
+        /// </summary>
+        protected override void CleanUp() { deflateEnd(ref _ztream); }
+
+    }
+}
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/DotZLib.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/DotZLib.cs
new file mode 100644
index 000000000..90c7c3b38
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/DotZLib.cs
@@ -0,0 +1,288 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Text;
+
+
+namespace DotZLib
+{
+
+    #region Internal types
+
+    /// <summary>
+    /// Defines constants for the various flush types used with zlib
+    /// </summary>
+    internal enum FlushTypes
+    {
+        None,  Partial,  Sync,  Full,  Finish,  Block
+    }
+
+    #region ZStream structure
+    // internal mapping of the zlib zstream structure for marshalling
+    [StructLayoutAttribute(LayoutKind.Sequential, Pack=4, Size=0, CharSet=CharSet.Ansi)]
+    internal struct ZStream
+    {
+        public IntPtr next_in;
+        public uint avail_in;
+        public uint total_in;
+
+        public IntPtr next_out;
+        public uint avail_out;
+        public uint total_out;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        string msg;
+        uint state;
+
+        uint zalloc;
+        uint zfree;
+        uint opaque;
+
+        int data_type;
+        public uint adler;
+        uint reserved;
+    }
+
+    #endregion
+
+    #endregion
+
+    #region Public enums
+    /// <summary>
+    /// Defines constants for the available compression levels in zlib
+    /// </summary>
+    public enum CompressLevel : int
+    {
+        /// <summary>
+        /// The default compression level with a reasonable compromise between compression and speed
+        /// </summary>
+        Default = -1,
+        /// <summary>
+        /// No compression at all. The data are passed straight through.
+        /// </summary>
+        None = 0,
+        /// <summary>
+        /// The maximum compression rate available.
+        /// </summary>
+        Best = 9,
+        /// <summary>
+        /// The fastest available compression level.
+        /// </summary>
+        Fastest = 1
+    }
+    #endregion
+
+    #region Exception classes
+    /// <summary>
+    /// The exception that is thrown when an error occurs on the zlib dll
+    /// </summary>
+    public class ZLibException : ApplicationException
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ZLibException"/> class with a specified
+        /// error message and error code
+        /// </summary>
+        /// <param name="errorCode">The zlib error code that caused the exception</param>
+        /// <param name="msg">A message that (hopefully) describes the error</param>
+        public ZLibException(int errorCode, string msg) : base(String.Format("ZLib error {0} {1}", errorCode, msg))
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ZLibException"/> class with a specified
+        /// error code
+        /// </summary>
+        /// <param name="errorCode">The zlib error code that caused the exception</param>
+        public ZLibException(int errorCode) : base(String.Format("ZLib error {0}", errorCode))
+        {
+        }
+    }
+    #endregion
+
+    #region Interfaces
+
+    /// <summary>
+    /// Declares methods and properties that enables a running checksum to be calculated
+    /// </summary>
+    public interface ChecksumGenerator
+    {
+        /// <summary>
+        /// Gets the current value of the checksum
+        /// </summary>
+        uint Value { get; }
+
+        /// <summary>
+        /// Clears the current checksum to 0
+        /// </summary>
+        void Reset();
+
+        /// <summary>
+        /// Updates the current checksum with an array of bytes
+        /// </summary>
+        /// <param name="data">The data to update the checksum with</param>
+        void Update(byte[] data);
+
+        /// <summary>
+        /// Updates the current checksum with part of an array of bytes
+        /// </summary>
+        /// <param name="data">The data to update the checksum with</param>
+        /// <param name="offset">Where in <c>data</c> to start updating</param>
+        /// <param name="count">The number of bytes from <c>data</c> to use</param>
+        /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+        /// <exception cref="ArgumentNullException"><c>data</c> is a null reference</exception>
+        /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+        void Update(byte[] data, int offset, int count);
+
+        /// <summary>
+        /// Updates the current checksum with the data from a string
+        /// </summary>
+        /// <param name="data">The string to update the checksum with</param>
+        /// <remarks>The characters in the string are converted by the UTF-8 encoding</remarks>
+        void Update(string data);
+
+        /// <summary>
+        /// Updates the current checksum with the data from a string, using a specific encoding
+        /// </summary>
+        /// <param name="data">The string to update the checksum with</param>
+        /// <param name="encoding">The encoding to use</param>
+        void Update(string data, Encoding encoding);
+    }
+
+
+    /// <summary>
+    /// Represents the method that will be called from a codec when new data
+    /// are available.
+    /// </summary>
+    /// <paramref name="data">The byte array containing the processed data</paramref>
+    /// <paramref name="startIndex">The index of the first processed byte in <c>data</c></paramref>
+    /// <paramref name="count">The number of processed bytes available</paramref>
+    /// <remarks>On return from this method, the data may be overwritten, so grab it while you can.
+    /// You cannot assume that startIndex will be zero.
+    /// </remarks>
+    public delegate void DataAvailableHandler(byte[] data, int startIndex, int count);
+
+    /// <summary>
+    /// Declares methods and events for implementing compressors/decompressors
+    /// </summary>
+    public interface Codec
+    {
+        /// <summary>
+        /// Occurs when more processed data are available.
+        /// </summary>
+        event DataAvailableHandler DataAvailable;
+
+        /// <summary>
+        /// Adds more data to the codec to be processed.
+        /// </summary>
+        /// <param name="data">Byte array containing the data to be added to the codec</param>
+        /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
+        void Add(byte[] data);
+
+        /// <summary>
+        /// Adds more data to the codec to be processed.
+        /// </summary>
+        /// <param name="data">Byte array containing the data to be added to the codec</param>
+        /// <param name="offset">The index of the first byte to add from <c>data</c></param>
+        /// <param name="count">The number of bytes to add</param>
+        /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
+        void Add(byte[] data, int offset, int count);
+
+        /// <summary>
+        /// Finishes up any pending data that needs to be processed and handled.
+        /// </summary>
+        void Finish();
+
+        /// <summary>
+        /// Gets the checksum of the data that has been added so far
+        /// </summary>
+        uint Checksum { get; }
+
+
+    }
+
+    #endregion
+
+    #region Classes
+    /// <summary>
+    /// Encapsulates general information about the ZLib library
+    /// </summary>
+    public class Info
+    {
+        #region DLL imports
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern uint zlibCompileFlags();
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern string zlibVersion();
+        #endregion
+
+        #region Private stuff
+        private uint _flags;
+
+        // helper function that unpacks a bitsize mask
+        private static int bitSize(uint bits)
+        {
+            switch (bits)
+            {
+                case 0: return 16;
+                case 1: return 32;
+                case 2: return 64;
+            }
+            return -1;
+        }
+        #endregion
+
+        /// <summary>
+        /// Constructs an instance of the <c>Info</c> class.
+        /// </summary>
+        public Info()
+        {
+            _flags = zlibCompileFlags();
+        }
+
+        /// <summary>
+        /// True if the library is compiled with debug info
+        /// </summary>
+        public bool HasDebugInfo { get { return 0 != (_flags & 0x100); } }
+
+        /// <summary>
+        /// True if the library is compiled with assembly optimizations
+        /// </summary>
+        public bool UsesAssemblyCode { get { return 0 != (_flags & 0x200); } }
+
+        /// <summary>
+        /// Gets the size of the unsigned int that was compiled into Zlib
+        /// </summary>
+        public int SizeOfUInt { get { return bitSize(_flags & 3); } }
+
+        /// <summary>
+        /// Gets the size of the unsigned long that was compiled into Zlib
+        /// </summary>
+        public int SizeOfULong { get { return bitSize((_flags >> 2) & 3); } }
+
+        /// <summary>
+        /// Gets the size of the pointers that were compiled into Zlib
+        /// </summary>
+        public int SizeOfPointer { get { return bitSize((_flags >> 4) & 3); } }
+
+        /// <summary>
+        /// Gets the size of the z_off_t type that was compiled into Zlib
+        /// </summary>
+        public int SizeOfOffset { get { return bitSize((_flags >> 6) & 3); } }
+
+        /// <summary>
+        /// Gets the version of ZLib as a string, e.g. "1.2.1"
+        /// </summary>
+        public static string Version { get { return zlibVersion(); } }
+    }
+
+    #endregion
+
+}
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/DotZLib.csproj b/xs/src/png/zlib/contrib/dotzlib/DotZLib/DotZLib.csproj
new file mode 100644
index 000000000..dea7fb16a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/DotZLib.csproj
@@ -0,0 +1,141 @@
+<VisualStudioProject>
+    <CSHARP
+        ProjectType = "Local"
+        ProductVersion = "7.10.3077"
+        SchemaVersion = "2.0"
+        ProjectGuid = "{BB1EE0B1-1808-46CB-B786-949D91117FC5}"
+    >
+        <Build>
+            <Settings
+                ApplicationIcon = ""
+                AssemblyKeyContainerName = ""
+                AssemblyName = "DotZLib"
+                AssemblyOriginatorKeyFile = ""
+                DefaultClientScript = "JScript"
+                DefaultHTMLPageLayout = "Grid"
+                DefaultTargetSchema = "IE50"
+                DelaySign = "false"
+                OutputType = "Library"
+                PreBuildEvent = ""
+                PostBuildEvent = ""
+                RootNamespace = "DotZLib"
+                RunPostBuildEvent = "OnBuildSuccess"
+                StartupObject = ""
+            >
+                <Config
+                    Name = "Debug"
+                    AllowUnsafeBlocks = "false"
+                    BaseAddress = "285212672"
+                    CheckForOverflowUnderflow = "false"
+                    ConfigurationOverrideFile = ""
+                    DefineConstants = "DEBUG;TRACE"
+                    DocumentationFile = "docs\DotZLib.xml"
+                    DebugSymbols = "true"
+                    FileAlignment = "4096"
+                    IncrementalBuild = "false"
+                    NoStdLib = "false"
+                    NoWarn = "1591"
+                    Optimize = "false"
+                    OutputPath = "bin\Debug\"
+                    RegisterForComInterop = "false"
+                    RemoveIntegerChecks = "false"
+                    TreatWarningsAsErrors = "false"
+                    WarningLevel = "4"
+                />
+                <Config
+                    Name = "Release"
+                    AllowUnsafeBlocks = "false"
+                    BaseAddress = "285212672"
+                    CheckForOverflowUnderflow = "false"
+                    ConfigurationOverrideFile = ""
+                    DefineConstants = "TRACE"
+                    DocumentationFile = "docs\DotZLib.xml"
+                    DebugSymbols = "false"
+                    FileAlignment = "4096"
+                    IncrementalBuild = "false"
+                    NoStdLib = "false"
+                    NoWarn = ""
+                    Optimize = "true"
+                    OutputPath = "bin\Release\"
+                    RegisterForComInterop = "false"
+                    RemoveIntegerChecks = "false"
+                    TreatWarningsAsErrors = "false"
+                    WarningLevel = "4"
+                />
+            </Settings>
+            <References>
+                <Reference
+                    Name = "System"
+                    AssemblyName = "System"
+                    HintPath = "C:\WINNT\Microsoft.NET\Framework\v1.1.4322\System.dll"
+                />
+                <Reference
+                    Name = "System.Data"
+                    AssemblyName = "System.Data"
+                    HintPath = "C:\WINNT\Microsoft.NET\Framework\v1.1.4322\System.Data.dll"
+                />
+                <Reference
+                    Name = "System.XML"
+                    AssemblyName = "System.Xml"
+                    HintPath = "C:\WINNT\Microsoft.NET\Framework\v1.1.4322\System.XML.dll"
+                />
+                <Reference
+                    Name = "nunit.framework"
+                    AssemblyName = "nunit.framework"
+                    HintPath = "E:\apps\NUnit V2.1\\bin\nunit.framework.dll"
+                    AssemblyFolderKey = "hklm\dn\nunit.framework"
+                />
+            </References>
+        </Build>
+        <Files>
+            <Include>
+                <File
+                    RelPath = "AssemblyInfo.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "ChecksumImpl.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "CircularBuffer.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "CodecBase.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "Deflater.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "DotZLib.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "GZipStream.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "Inflater.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "UnitTests.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+            </Include>
+        </Files>
+    </CSHARP>
+</VisualStudioProject>
+
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/GZipStream.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/GZipStream.cs
new file mode 100644
index 000000000..f0eada1d2
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/GZipStream.cs
@@ -0,0 +1,301 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+
+namespace DotZLib
+{
+	/// <summary>
+	/// Implements a compressed <see cref="Stream"/>, in GZip (.gz) format.
+	/// </summary>
+	public class GZipStream : Stream, IDisposable
+	{
+        #region Dll Imports
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl, CharSet=CharSet.Ansi)]
+        private static extern IntPtr gzopen(string name, string mode);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int gzclose(IntPtr gzFile);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int gzwrite(IntPtr gzFile, int data, int length);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int gzread(IntPtr gzFile, int data, int length);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int gzgetc(IntPtr gzFile);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int gzputc(IntPtr gzFile, int c);
+
+        #endregion
+
+        #region Private data
+        private IntPtr _gzFile;
+        private bool _isDisposed = false;
+        private bool _isWriting;
+        #endregion
+
+        #region Constructors
+        /// <summary>
+        /// Creates a new file as a writeable GZipStream
+        /// </summary>
+        /// <param name="fileName">The name of the compressed file to create</param>
+        /// <param name="level">The compression level to use when adding data</param>
+        /// <exception cref="ZLibException">If an error occurred in the internal zlib function</exception>
+		public GZipStream(string fileName, CompressLevel level)
+		{
+            _isWriting = true;
+            _gzFile = gzopen(fileName, String.Format("wb{0}", (int)level));
+            if (_gzFile == IntPtr.Zero)
+                throw new ZLibException(-1, "Could not open " + fileName);
+		}
+
+        /// <summary>
+        /// Opens an existing file as a readable GZipStream
+        /// </summary>
+        /// <param name="fileName">The name of the file to open</param>
+        /// <exception cref="ZLibException">If an error occurred in the internal zlib function</exception>
+        public GZipStream(string fileName)
+        {
+            _isWriting = false;
+            _gzFile = gzopen(fileName, "rb");
+            if (_gzFile == IntPtr.Zero)
+                throw new ZLibException(-1, "Could not open " + fileName);
+
+        }
+        #endregion
+
+        #region Access properties
+        /// <summary>
+        /// Returns true of this stream can be read from, false otherwise
+        /// </summary>
+        public override bool CanRead
+        {
+            get
+            {
+                return !_isWriting;
+            }
+        }
+
+
+        /// <summary>
+        /// Returns false.
+        /// </summary>
+        public override bool CanSeek
+        {
+            get
+            {
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Returns true if this tsream is writeable, false otherwise
+        /// </summary>
+        public override bool CanWrite
+        {
+            get
+            {
+                return _isWriting;
+            }
+        }
+        #endregion
+
+        #region Destructor & IDispose stuff
+
+        /// <summary>
+        /// Destroys this instance
+        /// </summary>
+        ~GZipStream()
+        {
+            cleanUp(false);
+        }
+
+        /// <summary>
+        /// Closes the external file handle
+        /// </summary>
+        public void Dispose()
+        {
+            cleanUp(true);
+        }
+
+        // Does the actual closing of the file handle.
+        private void cleanUp(bool isDisposing)
+        {
+            if (!_isDisposed)
+            {
+                gzclose(_gzFile);
+                _isDisposed = true;
+            }
+        }
+        #endregion
+
+        #region Basic reading and writing
+        /// <summary>
+        /// Attempts to read a number of bytes from the stream.
+        /// </summary>
+        /// <param name="buffer">The destination data buffer</param>
+        /// <param name="offset">The index of the first destination byte in <c>buffer</c></param>
+        /// <param name="count">The number of bytes requested</param>
+        /// <returns>The number of bytes read</returns>
+        /// <exception cref="ArgumentNullException">If <c>buffer</c> is null</exception>
+        /// <exception cref="ArgumentOutOfRangeException">If <c>count</c> or <c>offset</c> are negative</exception>
+        /// <exception cref="ArgumentException">If <c>offset</c>  + <c>count</c> is &gt; buffer.Length</exception>
+        /// <exception cref="NotSupportedException">If this stream is not readable.</exception>
+        /// <exception cref="ObjectDisposedException">If this stream has been disposed.</exception>
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            if (!CanRead) throw new NotSupportedException();
+            if (buffer == null) throw new ArgumentNullException();
+            if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+            if ((offset+count) > buffer.Length) throw new ArgumentException();
+            if (_isDisposed) throw new ObjectDisposedException("GZipStream");
+
+            GCHandle h = GCHandle.Alloc(buffer, GCHandleType.Pinned);
+            int result;
+            try
+            {
+                result = gzread(_gzFile, h.AddrOfPinnedObject().ToInt32() + offset, count);
+                if (result < 0)
+                    throw new IOException();
+            }
+            finally
+            {
+                h.Free();
+            }
+            return result;
+        }
+
+        /// <summary>
+        /// Attempts to read a single byte from the stream.
+        /// </summary>
+        /// <returns>The byte that was read, or -1 in case of error or End-Of-File</returns>
+        public override int ReadByte()
+        {
+            if (!CanRead) throw new NotSupportedException();
+            if (_isDisposed) throw new ObjectDisposedException("GZipStream");
+            return gzgetc(_gzFile);
+        }
+
+        /// <summary>
+        /// Writes a number of bytes to the stream
+        /// </summary>
+        /// <param name="buffer"></param>
+        /// <param name="offset"></param>
+        /// <param name="count"></param>
+        /// <exception cref="ArgumentNullException">If <c>buffer</c> is null</exception>
+        /// <exception cref="ArgumentOutOfRangeException">If <c>count</c> or <c>offset</c> are negative</exception>
+        /// <exception cref="ArgumentException">If <c>offset</c>  + <c>count</c> is &gt; buffer.Length</exception>
+        /// <exception cref="NotSupportedException">If this stream is not writeable.</exception>
+        /// <exception cref="ObjectDisposedException">If this stream has been disposed.</exception>
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            if (!CanWrite) throw new NotSupportedException();
+            if (buffer == null) throw new ArgumentNullException();
+            if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+            if ((offset+count) > buffer.Length) throw new ArgumentException();
+            if (_isDisposed) throw new ObjectDisposedException("GZipStream");
+
+            GCHandle h = GCHandle.Alloc(buffer, GCHandleType.Pinned);
+            try
+            {
+                int result = gzwrite(_gzFile, h.AddrOfPinnedObject().ToInt32() + offset, count);
+                if (result < 0)
+                    throw new IOException();
+            }
+            finally
+            {
+                h.Free();
+            }
+        }
+
+        /// <summary>
+        /// Writes a single byte to the stream
+        /// </summary>
+        /// <param name="value">The byte to add to the stream.</param>
+        /// <exception cref="NotSupportedException">If this stream is not writeable.</exception>
+        /// <exception cref="ObjectDisposedException">If this stream has been disposed.</exception>
+        public override void WriteByte(byte value)
+        {
+            if (!CanWrite) throw new NotSupportedException();
+            if (_isDisposed) throw new ObjectDisposedException("GZipStream");
+
+            int result = gzputc(_gzFile, (int)value);
+            if (result < 0)
+                throw new IOException();
+        }
+        #endregion
+
+        #region Position & length stuff
+        /// <summary>
+        /// Not supported.
+        /// </summary>
+        /// <param name="value"></param>
+        /// <exception cref="NotSupportedException">Always thrown</exception>
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException();
+        }
+
+        /// <summary>
+        ///  Not suppported.
+        /// </summary>
+        /// <param name="offset"></param>
+        /// <param name="origin"></param>
+        /// <returns></returns>
+        /// <exception cref="NotSupportedException">Always thrown</exception>
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new NotSupportedException();
+        }
+
+        /// <summary>
+        /// Flushes the <c>GZipStream</c>.
+        /// </summary>
+        /// <remarks>In this implementation, this method does nothing. This is because excessive
+        /// flushing may degrade the achievable compression rates.</remarks>
+        public override void Flush()
+        {
+            // left empty on purpose
+        }
+
+        /// <summary>
+        /// Gets/sets the current position in the <c>GZipStream</c>. Not suppported.
+        /// </summary>
+        /// <remarks>In this implementation this property is not supported</remarks>
+        /// <exception cref="NotSupportedException">Always thrown</exception>
+        public override long Position
+        {
+            get
+            {
+                throw new NotSupportedException();
+            }
+            set
+            {
+                throw new NotSupportedException();
+            }
+        }
+
+        /// <summary>
+        /// Gets the size of the stream. Not suppported.
+        /// </summary>
+        /// <remarks>In this implementation this property is not supported</remarks>
+        /// <exception cref="NotSupportedException">Always thrown</exception>
+        public override long Length
+        {
+            get
+            {
+                throw new NotSupportedException();
+            }
+        }
+        #endregion
+    }
+}
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/Inflater.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/Inflater.cs
new file mode 100644
index 000000000..d295f2680
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/Inflater.cs
@@ -0,0 +1,105 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace DotZLib
+{
+
+    /// <summary>
+    /// Implements a data decompressor, using the inflate algorithm in the ZLib dll
+    /// </summary>
+    public class Inflater : CodecBase
+	{
+        #region Dll imports
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl, CharSet=CharSet.Ansi)]
+        private static extern int inflateInit_(ref ZStream sz, string vs, int size);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int inflate(ref ZStream sz, int flush);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int inflateReset(ref ZStream sz);
+
+        [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+        private static extern int inflateEnd(ref ZStream sz);
+        #endregion
+
+        /// <summary>
+        /// Constructs an new instance of the <c>Inflater</c>
+        /// </summary>
+        public Inflater() : base()
+		{
+            int retval = inflateInit_(ref _ztream, Info.Version, Marshal.SizeOf(_ztream));
+            if (retval != 0)
+                throw new ZLibException(retval, "Could not initialize inflater");
+
+            resetOutput();
+        }
+
+
+        /// <summary>
+        /// Adds more data to the codec to be processed.
+        /// </summary>
+        /// <param name="data">Byte array containing the data to be added to the codec</param>
+        /// <param name="offset">The index of the first byte to add from <c>data</c></param>
+        /// <param name="count">The number of bytes to add</param>
+        /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>
+        public override void Add(byte[] data, int offset, int count)
+        {
+            if (data == null) throw new ArgumentNullException();
+            if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+            if ((offset+count) > data.Length) throw new ArgumentException();
+
+            int total = count;
+            int inputIndex = offset;
+            int err = 0;
+
+            while (err >= 0 && inputIndex < total)
+            {
+                copyInput(data, inputIndex, Math.Min(total - inputIndex, kBufferSize));
+                err = inflate(ref _ztream, (int)FlushTypes.None);
+                if (err == 0)
+                    while (_ztream.avail_out == 0)
+                    {
+                        OnDataAvailable();
+                        err = inflate(ref _ztream, (int)FlushTypes.None);
+                    }
+
+                inputIndex += (int)_ztream.total_in;
+            }
+            setChecksum( _ztream.adler );
+        }
+
+
+        /// <summary>
+        /// Finishes up any pending data that needs to be processed and handled.
+        /// </summary>
+        public override void Finish()
+        {
+            int err;
+            do
+            {
+                err = inflate(ref _ztream, (int)FlushTypes.Finish);
+                OnDataAvailable();
+            }
+            while (err == 0);
+            setChecksum( _ztream.adler );
+            inflateReset(ref _ztream);
+            resetOutput();
+        }
+
+        /// <summary>
+        /// Closes the internal zlib inflate stream
+        /// </summary>
+        protected override void CleanUp() { inflateEnd(ref _ztream); }
+
+
+	}
+}
diff --git a/xs/src/png/zlib/contrib/dotzlib/DotZLib/UnitTests.cs b/xs/src/png/zlib/contrib/dotzlib/DotZLib/UnitTests.cs
new file mode 100644
index 000000000..6d8aebb79
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/DotZLib/UnitTests.cs
@@ -0,0 +1,274 @@
+//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Collections;
+using System.IO;
+
+// uncomment the define below to include unit tests
+//#define nunit
+#if nunit
+using NUnit.Framework;
+
+// Unit tests for the DotZLib class library
+// ----------------------------------------
+//
+// Use this with NUnit 2 from http://www.nunit.org
+//
+
+namespace DotZLibTests
+{
+    using DotZLib;
+
+    // helper methods
+    internal class Utils
+    {
+        public static bool byteArrEqual( byte[] lhs, byte[] rhs )
+        {
+            if (lhs.Length != rhs.Length)
+                return false;
+            for (int i = lhs.Length-1; i >= 0; --i)
+                if (lhs[i] != rhs[i])
+                    return false;
+            return true;
+        }
+
+    }
+
+
+    [TestFixture]
+    public class CircBufferTests
+    {
+        #region Circular buffer tests
+        [Test]
+        public void SinglePutGet()
+        {
+            CircularBuffer buf = new CircularBuffer(10);
+            Assert.AreEqual( 0, buf.Size );
+            Assert.AreEqual( -1, buf.Get() );
+
+            Assert.IsTrue(buf.Put( 1 ));
+            Assert.AreEqual( 1, buf.Size );
+            Assert.AreEqual( 1, buf.Get() );
+            Assert.AreEqual( 0, buf.Size );
+            Assert.AreEqual( -1, buf.Get() );
+        }
+
+        [Test]
+        public void BlockPutGet()
+        {
+            CircularBuffer buf = new CircularBuffer(10);
+            byte[] arr = {1,2,3,4,5,6,7,8,9,10};
+            Assert.AreEqual( 10, buf.Put(arr,0,10) );
+            Assert.AreEqual( 10, buf.Size );
+            Assert.IsFalse( buf.Put(11) );
+            Assert.AreEqual( 1, buf.Get() );
+            Assert.IsTrue( buf.Put(11) );
+
+            byte[] arr2 = (byte[])arr.Clone();
+            Assert.AreEqual( 9, buf.Get(arr2,1,9) );
+            Assert.IsTrue( Utils.byteArrEqual(arr,arr2) );
+        }
+
+        #endregion
+    }
+
+    [TestFixture]
+    public class ChecksumTests
+    {
+        #region CRC32 Tests
+        [Test]
+        public void CRC32_Null()
+        {
+            CRC32Checksum crc32 = new CRC32Checksum();
+            Assert.AreEqual( 0, crc32.Value );
+
+            crc32 = new CRC32Checksum(1);
+            Assert.AreEqual( 1, crc32.Value );
+
+            crc32 = new CRC32Checksum(556);
+            Assert.AreEqual( 556, crc32.Value );
+        }
+
+        [Test]
+        public void CRC32_Data()
+        {
+            CRC32Checksum crc32 = new CRC32Checksum();
+            byte[] data = { 1,2,3,4,5,6,7 };
+            crc32.Update(data);
+            Assert.AreEqual( 0x70e46888, crc32.Value  );
+
+            crc32 = new CRC32Checksum();
+            crc32.Update("penguin");
+            Assert.AreEqual( 0x0e5c1a120, crc32.Value );
+
+            crc32 = new CRC32Checksum(1);
+            crc32.Update("penguin");
+            Assert.AreEqual(0x43b6aa94, crc32.Value);
+
+        }
+        #endregion
+
+        #region Adler tests
+
+        [Test]
+        public void Adler_Null()
+        {
+            AdlerChecksum adler = new AdlerChecksum();
+            Assert.AreEqual(0, adler.Value);
+
+            adler = new AdlerChecksum(1);
+            Assert.AreEqual( 1, adler.Value );
+
+            adler = new AdlerChecksum(556);
+            Assert.AreEqual( 556, adler.Value );
+        }
+
+        [Test]
+        public void Adler_Data()
+        {
+            AdlerChecksum adler = new AdlerChecksum(1);
+            byte[] data = { 1,2,3,4,5,6,7 };
+            adler.Update(data);
+            Assert.AreEqual( 0x5b001d, adler.Value  );
+
+            adler = new AdlerChecksum();
+            adler.Update("penguin");
+            Assert.AreEqual(0x0bcf02f6, adler.Value );
+
+            adler = new AdlerChecksum(1);
+            adler.Update("penguin");
+            Assert.AreEqual(0x0bd602f7, adler.Value);
+
+        }
+        #endregion
+    }
+
+    [TestFixture]
+    public class InfoTests
+    {
+        #region Info tests
+        [Test]
+        public void Info_Version()
+        {
+            Info info = new Info();
+            Assert.AreEqual("1.2.11", Info.Version);
+            Assert.AreEqual(32, info.SizeOfUInt);
+            Assert.AreEqual(32, info.SizeOfULong);
+            Assert.AreEqual(32, info.SizeOfPointer);
+            Assert.AreEqual(32, info.SizeOfOffset);
+        }
+        #endregion
+    }
+
+    [TestFixture]
+    public class DeflateInflateTests
+    {
+        #region Deflate tests
+        [Test]
+        public void Deflate_Init()
+        {
+            using (Deflater def = new Deflater(CompressLevel.Default))
+            {
+            }
+        }
+
+        private ArrayList compressedData = new ArrayList();
+        private uint adler1;
+
+        private ArrayList uncompressedData = new ArrayList();
+        private uint adler2;
+
+        public void CDataAvail(byte[] data, int startIndex, int count)
+        {
+            for (int i = 0; i < count; ++i)
+                compressedData.Add(data[i+startIndex]);
+        }
+
+        [Test]
+        public void Deflate_Compress()
+        {
+            compressedData.Clear();
+
+            byte[] testData = new byte[35000];
+            for (int i = 0; i < testData.Length; ++i)
+                testData[i] = 5;
+
+            using (Deflater def = new Deflater((CompressLevel)5))
+            {
+                def.DataAvailable += new DataAvailableHandler(CDataAvail);
+                def.Add(testData);
+                def.Finish();
+                adler1 = def.Checksum;
+            }
+        }
+        #endregion
+
+        #region Inflate tests
+        [Test]
+        public void Inflate_Init()
+        {
+            using (Inflater inf = new Inflater())
+            {
+            }
+        }
+
+        private void DDataAvail(byte[] data, int startIndex, int count)
+        {
+            for (int i = 0; i < count; ++i)
+                uncompressedData.Add(data[i+startIndex]);
+        }
+
+        [Test]
+        public void Inflate_Expand()
+        {
+            uncompressedData.Clear();
+
+            using (Inflater inf = new Inflater())
+            {
+                inf.DataAvailable += new DataAvailableHandler(DDataAvail);
+                inf.Add((byte[])compressedData.ToArray(typeof(byte)));
+                inf.Finish();
+                adler2 = inf.Checksum;
+            }
+            Assert.AreEqual( adler1, adler2 );
+        }
+        #endregion
+    }
+
+    [TestFixture]
+    public class GZipStreamTests
+    {
+        #region GZipStream test
+        [Test]
+        public void GZipStream_WriteRead()
+        {
+            using (GZipStream gzOut = new GZipStream("gzstream.gz", CompressLevel.Best))
+            {
+                BinaryWriter writer = new BinaryWriter(gzOut);
+                writer.Write("hi there");
+                writer.Write(Math.PI);
+                writer.Write(42);
+            }
+
+            using (GZipStream gzIn = new GZipStream("gzstream.gz"))
+            {
+                BinaryReader reader = new BinaryReader(gzIn);
+                string s = reader.ReadString();
+                Assert.AreEqual("hi there",s);
+                double d = reader.ReadDouble();
+                Assert.AreEqual(Math.PI, d);
+                int i = reader.ReadInt32();
+                Assert.AreEqual(42,i);
+            }
+
+        }
+        #endregion
+	}
+}
+
+#endif
diff --git a/xs/src/png/zlib/contrib/dotzlib/LICENSE_1_0.txt b/xs/src/png/zlib/contrib/dotzlib/LICENSE_1_0.txt
new file mode 100644
index 000000000..127a5bc39
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/LICENSE_1_0.txt
@@ -0,0 +1,23 @@
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/dotzlib/readme.txt b/xs/src/png/zlib/contrib/dotzlib/readme.txt
new file mode 100644
index 000000000..4d8c2dd93
--- /dev/null
+++ b/xs/src/png/zlib/contrib/dotzlib/readme.txt
@@ -0,0 +1,58 @@
+This directory contains a .Net wrapper class library for the ZLib1.dll
+
+The wrapper includes support for inflating/deflating memory buffers,
+.Net streaming wrappers for the gz streams part of zlib, and wrappers
+for the checksum parts of zlib. See DotZLib/UnitTests.cs for examples.
+
+Directory structure:
+--------------------
+
+LICENSE_1_0.txt       - License file.
+readme.txt            - This file.
+DotZLib.chm           - Class library documentation
+DotZLib.build         - NAnt build file
+DotZLib.sln           - Microsoft Visual Studio 2003 solution file
+
+DotZLib\*.cs          - Source files for the class library
+
+Unit tests:
+-----------
+The file DotZLib/UnitTests.cs contains unit tests for use with NUnit 2.1 or higher.
+To include unit tests in the build, define nunit before building.
+
+
+Build instructions:
+-------------------
+
+1. Using Visual Studio.Net 2003:
+   Open DotZLib.sln in VS.Net and build from there. Output file (DotZLib.dll)
+   will be found ./DotZLib/bin/release or ./DotZLib/bin/debug, depending on
+   you are building the release or debug version of the library. Check
+   DotZLib/UnitTests.cs for instructions on how to include unit tests in the
+   build.
+
+2. Using NAnt:
+   Open a command prompt with access to the build environment and run nant
+   in the same directory as the DotZLib.build file.
+   You can define 2 properties on the nant command-line to control the build:
+   debug={true|false} to toggle between release/debug builds (default=true).
+   nunit={true|false} to include or esclude unit tests (default=true).
+   Also the target clean will remove binaries.
+   Output file (DotZLib.dll) will be found in either ./DotZLib/bin/release
+   or ./DotZLib/bin/debug, depending on whether you are building the release
+   or debug version of the library.
+
+   Examples:
+     nant -D:debug=false -D:nunit=false
+       will build a release mode version of the library without unit tests.
+     nant
+       will build a debug version of the library with unit tests
+     nant clean
+       will remove all previously built files.
+
+
+---------------------------------
+Copyright (c) Henrik Ravn 2004
+
+Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+(See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/xs/src/png/zlib/contrib/gcc_gvmat64/gvmat64.S b/xs/src/png/zlib/contrib/gcc_gvmat64/gvmat64.S
new file mode 100644
index 000000000..23309fa28
--- /dev/null
+++ b/xs/src/png/zlib/contrib/gcc_gvmat64/gvmat64.S
@@ -0,0 +1,574 @@
+/*
+;uInt longest_match_x64(
+;    deflate_state *s,
+;    IPos cur_match);                             // current match 
+
+; gvmat64.S -- Asm portion of the optimized longest_match for 32 bits x86_64
+;  (AMD64 on Athlon 64, Opteron, Phenom
+;     and Intel EM64T on Pentium 4 with EM64T, Pentium D, Core 2 Duo, Core I5/I7)
+; this file is translation from gvmat64.asm to GCC 4.x (for Linux, Mac XCode)
+; Copyright (C) 1995-2010 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
+;
+; File written by Gilles Vollant, by converting to assembly the longest_match
+;  from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
+;  and by taking inspiration on asm686 with masm, optimised assembly code
+;        from Brian Raiter, written 1998
+;
+;  This software is provided 'as-is', without any express or implied
+;  warranty.  In no event will the authors be held liable for any damages
+;  arising from the use of this software.
+;
+;  Permission is granted to anyone to use this software for any purpose,
+;  including commercial applications, and to alter it and redistribute it
+;  freely, subject to the following restrictions:
+;
+;  1. The origin of this software must not be misrepresented; you must not
+;     claim that you wrote the original software. If you use this software
+;     in a product, an acknowledgment in the product documentation would be
+;     appreciated but is not required.
+;  2. Altered source versions must be plainly marked as such, and must not be
+;     misrepresented as being the original software
+;  3. This notice may not be removed or altered from any source distribution.
+;
+;         http://www.zlib.net
+;         http://www.winimage.com/zLibDll
+;         http://www.muppetlabs.com/~breadbox/software/assembly.html
+;
+; to compile this file for zLib, I use option:
+;   gcc -c -arch x86_64 gvmat64.S
+
+
+;uInt longest_match(s, cur_match)
+;    deflate_state *s;
+;    IPos cur_match;                             // current match /
+;
+; with XCode for Mac, I had strange error with some jump on intel syntax
+; this is why BEFORE_JMP and AFTER_JMP are used
+ */
+
+
+#define BEFORE_JMP .att_syntax
+#define AFTER_JMP .intel_syntax noprefix
+
+#ifndef NO_UNDERLINE
+#	define	match_init	_match_init
+#	define	longest_match	_longest_match
+#endif
+
+.intel_syntax noprefix
+
+.globl	match_init, longest_match
+.text
+longest_match:
+
+
+
+#define LocalVarsSize 96
+/*
+; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
+; free register :  r14,r15
+; register can be saved : rsp
+*/
+
+#define chainlenwmask     (rsp + 8 - LocalVarsSize)
+#define nicematch         (rsp + 16 - LocalVarsSize)
+
+#define save_rdi        (rsp + 24 - LocalVarsSize)
+#define save_rsi        (rsp + 32 - LocalVarsSize)
+#define save_rbx        (rsp + 40 - LocalVarsSize)
+#define save_rbp        (rsp + 48 - LocalVarsSize)
+#define save_r12        (rsp + 56 - LocalVarsSize)
+#define save_r13        (rsp + 64 - LocalVarsSize)
+#define save_r14        (rsp + 72 - LocalVarsSize)
+#define save_r15        (rsp + 80 - LocalVarsSize)
+
+
+/*
+;  all the +4 offsets are due to the addition of pending_buf_size (in zlib
+;  in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, remove the +4).
+;  Note : these value are good with a 8 bytes boundary pack structure
+*/
+
+#define    MAX_MATCH              258
+#define    MIN_MATCH              3
+#define    MIN_LOOKAHEAD          (MAX_MATCH+MIN_MATCH+1)
+
+/*
+;;; Offsets for fields in the deflate_state structure. These numbers
+;;; are calculated from the definition of deflate_state, with the
+;;; assumption that the compiler will dword-align the fields. (Thus,
+;;; changing the definition of deflate_state could easily cause this
+;;; program to crash horribly, without so much as a warning at
+;;; compile time. Sigh.)
+
+;  all the +zlib1222add offsets are due to the addition of fields
+;  in zlib in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
+;  (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
+;  if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
+*/
+
+
+
+/* you can check the structure offset by running
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "deflate.h"
+
+void print_depl()
+{
+deflate_state ds;
+deflate_state *s=&ds;
+printf("size pointer=%u\n",(int)sizeof(void*));
+
+printf("#define dsWSize         %u\n",(int)(((char*)&(s->w_size))-((char*)s)));
+printf("#define dsWMask         %u\n",(int)(((char*)&(s->w_mask))-((char*)s)));
+printf("#define dsWindow        %u\n",(int)(((char*)&(s->window))-((char*)s)));
+printf("#define dsPrev          %u\n",(int)(((char*)&(s->prev))-((char*)s)));
+printf("#define dsMatchLen      %u\n",(int)(((char*)&(s->match_length))-((char*)s)));
+printf("#define dsPrevMatch     %u\n",(int)(((char*)&(s->prev_match))-((char*)s)));
+printf("#define dsStrStart      %u\n",(int)(((char*)&(s->strstart))-((char*)s)));
+printf("#define dsMatchStart    %u\n",(int)(((char*)&(s->match_start))-((char*)s)));
+printf("#define dsLookahead     %u\n",(int)(((char*)&(s->lookahead))-((char*)s)));
+printf("#define dsPrevLen       %u\n",(int)(((char*)&(s->prev_length))-((char*)s)));
+printf("#define dsMaxChainLen   %u\n",(int)(((char*)&(s->max_chain_length))-((char*)s)));
+printf("#define dsGoodMatch     %u\n",(int)(((char*)&(s->good_match))-((char*)s)));
+printf("#define dsNiceMatch     %u\n",(int)(((char*)&(s->nice_match))-((char*)s)));
+}
+*/
+
+#define dsWSize          68
+#define dsWMask          76
+#define dsWindow         80
+#define dsPrev           96
+#define dsMatchLen       144
+#define dsPrevMatch      148
+#define dsStrStart       156
+#define dsMatchStart     160
+#define dsLookahead      164
+#define dsPrevLen        168
+#define dsMaxChainLen    172
+#define dsGoodMatch      188
+#define dsNiceMatch      192
+
+#define window_size      [ rcx + dsWSize]
+#define WMask            [ rcx + dsWMask]
+#define window_ad        [ rcx + dsWindow]
+#define prev_ad          [ rcx + dsPrev]
+#define strstart         [ rcx + dsStrStart]
+#define match_start      [ rcx + dsMatchStart]
+#define Lookahead        [ rcx + dsLookahead] //; 0ffffffffh on infozip
+#define prev_length      [ rcx + dsPrevLen]
+#define max_chain_length [ rcx + dsMaxChainLen]
+#define good_match       [ rcx + dsGoodMatch]
+#define nice_match       [ rcx + dsNiceMatch]
+
+/*
+; windows:
+; parameter 1 in rcx(deflate state s), param 2 in rdx (cur match)
+
+; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
+; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
+;
+; All registers must be preserved across the call, except for
+;   rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
+
+;
+; gcc on macosx-linux:
+; see http://www.x86-64.org/documentation/abi-0.99.pdf
+; param 1 in rdi, param 2 in rsi
+; rbx, rsp, rbp, r12 to r15 must be preserved
+
+;;; Save registers that the compiler may be using, and adjust esp to
+;;; make room for our stack frame.
+
+
+;;; Retrieve the function arguments. r8d will hold cur_match
+;;; throughout the entire function. edx will hold the pointer to the
+;;; deflate_state structure during the function's setup (before
+;;; entering the main loop.
+
+; ms: parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
+; mac: param 1 in rdi, param 2 rsi
+; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
+*/
+        mov [save_rbx],rbx
+        mov [save_rbp],rbp
+
+
+        mov rcx,rdi
+
+        mov r8d,esi
+
+
+        mov [save_r12],r12
+        mov [save_r13],r13
+        mov [save_r14],r14
+        mov [save_r15],r15
+
+
+//;;; uInt wmask = s->w_mask;
+//;;; unsigned chain_length = s->max_chain_length;
+//;;; if (s->prev_length >= s->good_match) {
+//;;;     chain_length >>= 2;
+//;;; }
+
+
+        mov edi, prev_length
+        mov esi, good_match
+        mov eax, WMask
+        mov ebx, max_chain_length
+        cmp edi, esi
+        jl  LastMatchGood
+        shr ebx, 2
+LastMatchGood:
+
+//;;; chainlen is decremented once beforehand so that the function can
+//;;; use the sign flag instead of the zero flag for the exit test.
+//;;; It is then shifted into the high word, to make room for the wmask
+//;;; value, which it will always accompany.
+
+        dec ebx
+        shl ebx, 16
+        or  ebx, eax
+
+//;;; on zlib only
+//;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
+
+
+
+        mov eax, nice_match
+        mov [chainlenwmask], ebx
+        mov r10d, Lookahead
+        cmp r10d, eax
+        cmovnl r10d, eax
+        mov [nicematch],r10d
+
+
+
+//;;; register Bytef *scan = s->window + s->strstart;
+        mov r10, window_ad
+        mov ebp, strstart
+        lea r13, [r10 + rbp]
+
+//;;; Determine how many bytes the scan ptr is off from being
+//;;; dword-aligned.
+
+         mov r9,r13
+         neg r13
+         and r13,3
+
+//;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+//;;;     s->strstart - (IPos)MAX_DIST(s) : NIL;
+
+
+        mov eax, window_size
+        sub eax, MIN_LOOKAHEAD
+
+
+        xor edi,edi
+        sub ebp, eax
+
+        mov r11d, prev_length
+
+        cmovng ebp,edi
+
+//;;; int best_len = s->prev_length;
+
+
+//;;; Store the sum of s->window + best_len in esi locally, and in esi.
+
+       lea  rsi,[r10+r11]
+
+//;;; register ush scan_start = *(ushf*)scan;
+//;;; register ush scan_end   = *(ushf*)(scan+best_len-1);
+//;;; Posf *prev = s->prev;
+
+        movzx r12d,word ptr [r9]
+        movzx ebx, word ptr [r9 + r11 - 1]
+
+        mov rdi, prev_ad
+
+//;;; Jump into the main loop.
+
+        mov edx, [chainlenwmask]
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+				
+						
+						
+LookupLoop1:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+		
+		
+		
+        sub edx, 0x00010000
+		BEFORE_JMP
+        js  LeaveNow
+		AFTER_JMP
+
+LoopEntry1:
+        cmp bx,word ptr [rsi + r8 - 1]
+		BEFORE_JMP
+        jz  LookupLoopIsZero
+		AFTER_JMP
+
+LookupLoop2:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+		BEFORE_JMP
+        jbe LeaveNow
+		AFTER_JMP
+        sub edx, 0x00010000
+		BEFORE_JMP
+        js  LeaveNow
+		AFTER_JMP
+
+LoopEntry2:
+        cmp bx,word ptr [rsi + r8 - 1]
+		BEFORE_JMP
+        jz  LookupLoopIsZero
+		AFTER_JMP
+
+LookupLoop4:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+		BEFORE_JMP
+        jbe LeaveNow
+		AFTER_JMP
+        sub edx, 0x00010000
+		BEFORE_JMP
+        js  LeaveNow
+		AFTER_JMP
+
+LoopEntry4:
+
+        cmp bx,word ptr [rsi + r8 - 1]
+		BEFORE_JMP
+        jnz LookupLoop1
+        jmp LookupLoopIsZero
+		AFTER_JMP
+/*
+;;; do {
+;;;     match = s->window + cur_match;
+;;;     if (*(ushf*)(match+best_len-1) != scan_end ||
+;;;         *(ushf*)match != scan_start) continue;
+;;;     [...]
+;;; } while ((cur_match = prev[cur_match & wmask]) > limit
+;;;          && --chain_length != 0);
+;;;
+;;; Here is the inner loop of the function. The function will spend the
+;;; majority of its time in this loop, and majority of that time will
+;;; be spent in the first ten instructions.
+;;;
+;;; Within this loop:
+;;; ebx = scanend
+;;; r8d = curmatch
+;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
+;;; esi = windowbestlen - i.e., (window + bestlen)
+;;; edi = prev
+;;; ebp = limit
+*/
+.balign 16
+LookupLoop:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+		BEFORE_JMP
+        jbe LeaveNow
+		AFTER_JMP
+        sub edx, 0x00010000
+		BEFORE_JMP
+        js  LeaveNow
+		AFTER_JMP
+
+LoopEntry:
+
+        cmp bx,word ptr [rsi + r8 - 1]
+		BEFORE_JMP
+        jnz LookupLoop1
+		AFTER_JMP
+LookupLoopIsZero:
+        cmp     r12w, word ptr [r10 + r8]
+		BEFORE_JMP
+        jnz LookupLoop1
+		AFTER_JMP
+
+
+//;;; Store the current value of chainlen.
+        mov [chainlenwmask], edx
+/*
+;;; Point edi to the string under scrutiny, and esi to the string we
+;;; are hoping to match it up with. In actuality, esi and edi are
+;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
+;;; initialized to -(MAX_MATCH_8 - scanalign).
+*/
+        lea rsi,[r8+r10]
+        mov rdx, 0xfffffffffffffef8 //; -(MAX_MATCH_8)
+        lea rsi, [rsi + r13 + 0x0108] //;MAX_MATCH_8]
+        lea rdi, [r9 + r13 + 0x0108] //;MAX_MATCH_8]
+
+        prefetcht1 [rsi+rdx]
+        prefetcht1 [rdi+rdx]
+
+/*
+;;; Test the strings for equality, 8 bytes at a time. At the end,
+;;; adjust rdx so that it is offset to the exact byte that mismatched.
+;;;
+;;; We already know at this point that the first three bytes of the
+;;; strings match each other, and they can be safely passed over before
+;;; starting the compare loop. So what this code does is skip over 0-3
+;;; bytes, as much as necessary in order to dword-align the edi
+;;; pointer. (rsi will still be misaligned three times out of four.)
+;;;
+;;; It should be confessed that this loop usually does not represent
+;;; much of the total running time. Replacing it with a more
+;;; straightforward "rep cmpsb" would not drastically degrade
+;;; performance.
+*/
+
+LoopCmps:
+        mov rax, [rsi + rdx]
+        xor rax, [rdi + rdx]
+        jnz LeaveLoopCmps
+
+        mov rax, [rsi + rdx + 8]
+        xor rax, [rdi + rdx + 8]
+        jnz LeaveLoopCmps8
+
+
+        mov rax, [rsi + rdx + 8+8]
+        xor rax, [rdi + rdx + 8+8]
+        jnz LeaveLoopCmps16
+
+        add rdx,8+8+8
+
+		BEFORE_JMP
+        jnz  LoopCmps
+        jmp  LenMaximum
+		AFTER_JMP
+		
+LeaveLoopCmps16: add rdx,8
+LeaveLoopCmps8: add rdx,8
+LeaveLoopCmps:
+
+        test    eax, 0x0000FFFF
+        jnz LenLower
+
+        test eax,0xffffffff
+
+        jnz LenLower32
+
+        add rdx,4
+        shr rax,32
+        or ax,ax
+		BEFORE_JMP
+        jnz LenLower
+		AFTER_JMP
+
+LenLower32:
+        shr eax,16
+        add rdx,2
+		
+LenLower:		
+        sub al, 1
+        adc rdx, 0
+//;;; Calculate the length of the match. If it is longer than MAX_MATCH,
+//;;; then automatically accept it as the best possible match and leave.
+
+        lea rax, [rdi + rdx]
+        sub rax, r9
+        cmp eax, MAX_MATCH
+		BEFORE_JMP
+        jge LenMaximum
+		AFTER_JMP
+/*
+;;; If the length of the match is not longer than the best match we
+;;; have so far, then forget it and return to the lookup loop.
+;///////////////////////////////////
+*/
+        cmp eax, r11d
+        jg  LongerMatch
+
+        lea rsi,[r10+r11]
+
+        mov rdi, prev_ad
+        mov edx, [chainlenwmask]
+		BEFORE_JMP
+        jmp LookupLoop
+		AFTER_JMP
+/*
+;;;         s->match_start = cur_match;
+;;;         best_len = len;
+;;;         if (len >= nice_match) break;
+;;;         scan_end = *(ushf*)(scan+best_len-1);
+*/
+LongerMatch:
+        mov r11d, eax
+        mov match_start, r8d
+        cmp eax, [nicematch]
+		BEFORE_JMP
+        jge LeaveNow
+		AFTER_JMP
+
+        lea rsi,[r10+rax]
+
+        movzx   ebx, word ptr [r9 + rax - 1]
+        mov rdi, prev_ad
+        mov edx, [chainlenwmask]
+		BEFORE_JMP
+        jmp LookupLoop
+		AFTER_JMP
+
+//;;; Accept the current string, with the maximum possible length.
+
+LenMaximum:
+        mov r11d,MAX_MATCH
+        mov match_start, r8d
+
+//;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+//;;; return s->lookahead;
+
+LeaveNow:
+        mov eax, Lookahead
+        cmp r11d, eax
+        cmovng eax, r11d
+
+
+
+//;;; Restore the stack and return from whence we came.
+
+
+//        mov rsi,[save_rsi]
+//        mov rdi,[save_rdi]
+        mov rbx,[save_rbx]
+        mov rbp,[save_rbp]
+        mov r12,[save_r12]
+        mov r13,[save_r13]
+        mov r14,[save_r14]
+        mov r15,[save_r15]
+
+
+        ret 0
+//; please don't remove this string !
+//; Your can freely use gvmat64 in any free or commercial app
+//; but it is far better don't remove the string in the binary!
+ //   db     0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998, converted to amd 64 by Gilles Vollant 2005",0dh,0ah,0
+
+
+match_init:
+  ret 0
+
+
diff --git a/xs/src/png/zlib/contrib/infback9/README b/xs/src/png/zlib/contrib/infback9/README
new file mode 100644
index 000000000..e75ed1329
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/README
@@ -0,0 +1 @@
+See infback9.h for what this is and how to use it.
diff --git a/xs/src/png/zlib/contrib/infback9/infback9.c b/xs/src/png/zlib/contrib/infback9/infback9.c
new file mode 100644
index 000000000..05fb3e338
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/infback9.c
@@ -0,0 +1,615 @@
+/* infback9.c -- inflate deflate64 data using a call-back interface
+ * Copyright (C) 1995-2008 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "infback9.h"
+#include "inftree9.h"
+#include "inflate9.h"
+
+#define WSIZE 65536UL
+
+/*
+   strm provides memory allocation functions in zalloc and zfree, or
+   Z_NULL to use the library memory allocation functions.
+
+   window is a user-supplied window and output buffer that is 64K bytes.
+ */
+int ZEXPORT inflateBack9Init_(strm, window, version, stream_size)
+z_stream FAR *strm;
+unsigned char FAR *window;
+const char *version;
+int stream_size;
+{
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL || window == Z_NULL)
+        return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+    }
+    if (strm->zfree == (free_func)0) strm->zfree = zcfree;
+    state = (struct inflate_state FAR *)ZALLOC(strm, 1,
+                                               sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (voidpf)state;
+    state->window = window;
+    return Z_OK;
+}
+
+/*
+   Build and output length and distance decoding tables for fixed code
+   decoding.
+ */
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+void makefixed9(void)
+{
+    unsigned sym, bits, low, size;
+    code *next, *lenfix, *distfix;
+    struct inflate_state state;
+    code fixed[544];
+
+    /* literal/length table */
+    sym = 0;
+    while (sym < 144) state.lens[sym++] = 8;
+    while (sym < 256) state.lens[sym++] = 9;
+    while (sym < 280) state.lens[sym++] = 7;
+    while (sym < 288) state.lens[sym++] = 8;
+    next = fixed;
+    lenfix = next;
+    bits = 9;
+    inflate_table9(LENS, state.lens, 288, &(next), &(bits), state.work);
+
+    /* distance table */
+    sym = 0;
+    while (sym < 32) state.lens[sym++] = 5;
+    distfix = next;
+    bits = 5;
+    inflate_table9(DISTS, state.lens, 32, &(next), &(bits), state.work);
+
+    /* write tables */
+    puts("    /* inffix9.h -- table for decoding deflate64 fixed codes");
+    puts("     * Generated automatically by makefixed9().");
+    puts("     */");
+    puts("");
+    puts("    /* WARNING: this file should *not* be used by applications.");
+    puts("       It is part of the implementation of this library and is");
+    puts("       subject to change. Applications should only use zlib.h.");
+    puts("     */");
+    puts("");
+    size = 1U << 9;
+    printf("    static const code lenfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 6) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", lenfix[low].op, lenfix[low].bits,
+               lenfix[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+    size = 1U << 5;
+    printf("\n    static const code distfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 5) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", distfix[low].op, distfix[low].bits,
+               distfix[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+}
+#endif /* MAKEFIXED */
+
+/* Macros for inflateBack(): */
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Assure that some input is available.  If input is requested, but denied,
+   then return a Z_BUF_ERROR from inflateBack(). */
+#define PULL() \
+    do { \
+        if (have == 0) { \
+            have = in(in_desc, &next); \
+            if (have == 0) { \
+                next = Z_NULL; \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflateBack()
+   with an error if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        PULL(); \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflateBack() with
+   an error. */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n <= 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Assure that some output space is available, by writing out the window
+   if it's full.  If the write fails, return from inflateBack() with a
+   Z_BUF_ERROR. */
+#define ROOM() \
+    do { \
+        if (left == 0) { \
+            put = window; \
+            left = WSIZE; \
+            wrap = 1; \
+            if (out(out_desc, put, (unsigned)left)) { \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/*
+   strm provides the memory allocation functions and window buffer on input,
+   and provides information on the unused input on return.  For Z_DATA_ERROR
+   returns, strm will also provide an error message.
+
+   in() and out() are the call-back input and output functions.  When
+   inflateBack() needs more input, it calls in().  When inflateBack() has
+   filled the window with output, or when it completes with data in the
+   window, it calls out() to write out the data.  The application must not
+   change the provided input until in() is called again or inflateBack()
+   returns.  The application must not change the window/output buffer until
+   inflateBack() returns.
+
+   in() and out() are called with a descriptor parameter provided in the
+   inflateBack() call.  This parameter can be a structure that provides the
+   information required to do the read or write, as well as accumulated
+   information on the input and output such as totals and check values.
+
+   in() should return zero on failure.  out() should return non-zero on
+   failure.  If either in() or out() fails, than inflateBack() returns a
+   Z_BUF_ERROR.  strm->next_in can be checked for Z_NULL to see whether it
+   was in() or out() that caused in the error.  Otherwise,  inflateBack()
+   returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
+   error, or Z_MEM_ERROR if it could not allocate memory for the state.
+   inflateBack() can also return Z_STREAM_ERROR if the input parameters
+   are not correct, i.e. strm is Z_NULL or the state was not initialized.
+ */
+int ZEXPORT inflateBack9(strm, in, in_desc, out, out_desc)
+z_stream FAR *strm;
+in_func in;
+void FAR *in_desc;
+out_func out;
+void FAR *out_desc;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have;              /* available input */
+    unsigned long left;         /* available output */
+    inflate_mode mode;          /* current inflate mode */
+    int lastblock;              /* true if processing last block */
+    int wrap;                   /* true if the window has wrapped */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned extra;             /* extra bits needed */
+    unsigned long length;       /* literal or length of data to copy */
+    unsigned long offset;       /* distance back to copy string from */
+    unsigned long copy;         /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code const FAR *lencode;    /* starting table for length/literal codes */
+    code const FAR *distcode;   /* starting table for distance codes */
+    unsigned lenbits;           /* index bits for lencode */
+    unsigned distbits;          /* index bits for distcode */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+#include "inffix9.h"
+
+    /* Check that the strm exists and that the state was initialized */
+    if (strm == Z_NULL || strm->state == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* Reset the state */
+    strm->msg = Z_NULL;
+    mode = TYPE;
+    lastblock = 0;
+    wrap = 0;
+    window = state->window;
+    next = strm->next_in;
+    have = next != Z_NULL ? strm->avail_in : 0;
+    hold = 0;
+    bits = 0;
+    put = window;
+    left = WSIZE;
+    lencode = Z_NULL;
+    distcode = Z_NULL;
+
+    /* Inflate until end of block marked as last */
+    for (;;)
+        switch (mode) {
+        case TYPE:
+            /* determine and dispatch block type */
+            if (lastblock) {
+                BYTEBITS();
+                mode = DONE;
+                break;
+            }
+            NEEDBITS(3);
+            lastblock = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        lastblock ? " (last)" : ""));
+                mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                lencode = lenfix;
+                lenbits = 9;
+                distcode = distfix;
+                distbits = 5;
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        lastblock ? " (last)" : ""));
+                mode = LEN;                     /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        lastblock ? " (last)" : ""));
+                mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+
+        case STORED:
+            /* get and verify stored block length */
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                mode = BAD;
+                break;
+            }
+            length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %lu\n",
+                    length));
+            INITBITS();
+
+            /* copy stored block from input to output */
+            while (length != 0) {
+                copy = length;
+                PULL();
+                ROOM();
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                length -= copy;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            mode = TYPE;
+            break;
+
+        case TABLE:
+            /* get dynamic table entries descriptor */
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+            if (state->nlen > 286) {
+                strm->msg = (char *)"too many length symbols";
+                mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+
+            /* get code length code lengths (not a typo) */
+            state->have = 0;
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            lencode = (code const FAR *)(state->next);
+            lenbits = 7;
+            ret = inflate_table9(CODES, state->lens, 19, &(state->next),
+                                &(lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+
+            /* get length and distance code code lengths */
+            state->have = 0;
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = lencode[BITS(lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    NEEDBITS(here.bits);
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            mode = BAD;
+                            break;
+                        }
+                        len = (unsigned)(state->lens[state->have - 1]);
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftree9.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            lencode = (code const FAR *)(state->next);
+            lenbits = 9;
+            ret = inflate_table9(LENS, state->lens, state->nlen,
+                            &(state->next), &(lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                mode = BAD;
+                break;
+            }
+            distcode = (code const FAR *)(state->next);
+            distbits = 6;
+            ret = inflate_table9(DISTS, state->lens + state->nlen,
+                            state->ndist, &(state->next), &(distbits),
+                            state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            mode = LEN;
+
+        case LEN:
+            /* get a literal, length, or end-of-block code */
+            for (;;) {
+                here = lencode[BITS(lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            length = (unsigned)here.val;
+
+            /* process literal */
+            if (here.op == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                ROOM();
+                *put++ = (unsigned char)(length);
+                left--;
+                mode = LEN;
+                break;
+            }
+
+            /* process end of block */
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                mode = TYPE;
+                break;
+            }
+
+            /* invalid code */
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                mode = BAD;
+                break;
+            }
+
+            /* length code -- get extra bits, if any */
+            extra = (unsigned)(here.op) & 31;
+            if (extra != 0) {
+                NEEDBITS(extra);
+                length += BITS(extra);
+                DROPBITS(extra);
+            }
+            Tracevv((stderr, "inflate:         length %lu\n", length));
+
+            /* get distance code */
+            for (;;) {
+                here = distcode[BITS(distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                mode = BAD;
+                break;
+            }
+            offset = (unsigned)here.val;
+
+            /* get distance extra bits, if any */
+            extra = (unsigned)(here.op) & 15;
+            if (extra != 0) {
+                NEEDBITS(extra);
+                offset += BITS(extra);
+                DROPBITS(extra);
+            }
+            if (offset > WSIZE - (wrap ? 0: left)) {
+                strm->msg = (char *)"invalid distance too far back";
+                mode = BAD;
+                break;
+            }
+            Tracevv((stderr, "inflate:         distance %lu\n", offset));
+
+            /* copy match from window to output */
+            do {
+                ROOM();
+                copy = WSIZE - offset;
+                if (copy < left) {
+                    from = put + copy;
+                    copy = left - copy;
+                }
+                else {
+                    from = put - offset;
+                    copy = left;
+                }
+                if (copy > length) copy = length;
+                length -= copy;
+                left -= copy;
+                do {
+                    *put++ = *from++;
+                } while (--copy);
+            } while (length != 0);
+            break;
+
+        case DONE:
+            /* inflate stream terminated properly -- write leftover output */
+            ret = Z_STREAM_END;
+            if (left < WSIZE) {
+                if (out(out_desc, window, (unsigned)(WSIZE - left)))
+                    ret = Z_BUF_ERROR;
+            }
+            goto inf_leave;
+
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+
+        default:                /* can't happen, but makes compilers happy */
+            ret = Z_STREAM_ERROR;
+            goto inf_leave;
+        }
+
+    /* Return unused input */
+  inf_leave:
+    strm->next_in = next;
+    strm->avail_in = have;
+    return ret;
+}
+
+int ZEXPORT inflateBack9End(strm)
+z_stream FAR *strm;
+{
+    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+        return Z_STREAM_ERROR;
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
diff --git a/xs/src/png/zlib/contrib/infback9/infback9.h b/xs/src/png/zlib/contrib/infback9/infback9.h
new file mode 100644
index 000000000..1073c0a38
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/infback9.h
@@ -0,0 +1,37 @@
+/* infback9.h -- header for using inflateBack9 functions
+ * Copyright (C) 2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * This header file and associated patches provide a decoder for PKWare's
+ * undocumented deflate64 compression method (method 9).  Use with infback9.c,
+ * inftree9.h, inftree9.c, and inffix9.h.  These patches are not supported.
+ * This should be compiled with zlib, since it uses zutil.h and zutil.o.
+ * This code has not yet been tested on 16-bit architectures.  See the
+ * comments in zlib.h for inflateBack() usage.  These functions are used
+ * identically, except that there is no windowBits parameter, and a 64K
+ * window must be provided.  Also if int's are 16 bits, then a zero for
+ * the third parameter of the "out" function actually means 65536UL.
+ * zlib.h must be included before this header file.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+ZEXTERN int ZEXPORT inflateBack9 OF((z_stream FAR *strm,
+                                    in_func in, void FAR *in_desc,
+                                    out_func out, void FAR *out_desc));
+ZEXTERN int ZEXPORT inflateBack9End OF((z_stream FAR *strm));
+ZEXTERN int ZEXPORT inflateBack9Init_ OF((z_stream FAR *strm,
+                                         unsigned char FAR *window,
+                                         const char *version,
+                                         int stream_size));
+#define inflateBack9Init(strm, window) \
+        inflateBack9Init_((strm), (window), \
+        ZLIB_VERSION, sizeof(z_stream))
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/xs/src/png/zlib/contrib/infback9/inffix9.h b/xs/src/png/zlib/contrib/infback9/inffix9.h
new file mode 100644
index 000000000..ee5671d2d
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/inffix9.h
@@ -0,0 +1,107 @@
+    /* inffix9.h -- table for decoding deflate64 fixed codes
+     * Generated automatically by makefixed9().
+     */
+
+    /* WARNING: this file should *not* be used by applications.
+       It is part of the implementation of this library and is
+       subject to change. Applications should only use zlib.h.
+     */
+
+    static const code lenfix[512] = {
+        {96,7,0},{0,8,80},{0,8,16},{132,8,115},{130,7,31},{0,8,112},
+        {0,8,48},{0,9,192},{128,7,10},{0,8,96},{0,8,32},{0,9,160},
+        {0,8,0},{0,8,128},{0,8,64},{0,9,224},{128,7,6},{0,8,88},
+        {0,8,24},{0,9,144},{131,7,59},{0,8,120},{0,8,56},{0,9,208},
+        {129,7,17},{0,8,104},{0,8,40},{0,9,176},{0,8,8},{0,8,136},
+        {0,8,72},{0,9,240},{128,7,4},{0,8,84},{0,8,20},{133,8,227},
+        {131,7,43},{0,8,116},{0,8,52},{0,9,200},{129,7,13},{0,8,100},
+        {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},
+        {128,7,8},{0,8,92},{0,8,28},{0,9,152},{132,7,83},{0,8,124},
+        {0,8,60},{0,9,216},{130,7,23},{0,8,108},{0,8,44},{0,9,184},
+        {0,8,12},{0,8,140},{0,8,76},{0,9,248},{128,7,3},{0,8,82},
+        {0,8,18},{133,8,163},{131,7,35},{0,8,114},{0,8,50},{0,9,196},
+        {129,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},{0,8,130},
+        {0,8,66},{0,9,228},{128,7,7},{0,8,90},{0,8,26},{0,9,148},
+        {132,7,67},{0,8,122},{0,8,58},{0,9,212},{130,7,19},{0,8,106},
+        {0,8,42},{0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},
+        {128,7,5},{0,8,86},{0,8,22},{65,8,0},{131,7,51},{0,8,118},
+        {0,8,54},{0,9,204},{129,7,15},{0,8,102},{0,8,38},{0,9,172},
+        {0,8,6},{0,8,134},{0,8,70},{0,9,236},{128,7,9},{0,8,94},
+        {0,8,30},{0,9,156},{132,7,99},{0,8,126},{0,8,62},{0,9,220},
+        {130,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
+        {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{133,8,131},
+        {130,7,31},{0,8,113},{0,8,49},{0,9,194},{128,7,10},{0,8,97},
+        {0,8,33},{0,9,162},{0,8,1},{0,8,129},{0,8,65},{0,9,226},
+        {128,7,6},{0,8,89},{0,8,25},{0,9,146},{131,7,59},{0,8,121},
+        {0,8,57},{0,9,210},{129,7,17},{0,8,105},{0,8,41},{0,9,178},
+        {0,8,9},{0,8,137},{0,8,73},{0,9,242},{128,7,4},{0,8,85},
+        {0,8,21},{144,8,3},{131,7,43},{0,8,117},{0,8,53},{0,9,202},
+        {129,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},
+        {0,8,69},{0,9,234},{128,7,8},{0,8,93},{0,8,29},{0,9,154},
+        {132,7,83},{0,8,125},{0,8,61},{0,9,218},{130,7,23},{0,8,109},
+        {0,8,45},{0,9,186},{0,8,13},{0,8,141},{0,8,77},{0,9,250},
+        {128,7,3},{0,8,83},{0,8,19},{133,8,195},{131,7,35},{0,8,115},
+        {0,8,51},{0,9,198},{129,7,11},{0,8,99},{0,8,35},{0,9,166},
+        {0,8,3},{0,8,131},{0,8,67},{0,9,230},{128,7,7},{0,8,91},
+        {0,8,27},{0,9,150},{132,7,67},{0,8,123},{0,8,59},{0,9,214},
+        {130,7,19},{0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},
+        {0,8,75},{0,9,246},{128,7,5},{0,8,87},{0,8,23},{77,8,0},
+        {131,7,51},{0,8,119},{0,8,55},{0,9,206},{129,7,15},{0,8,103},
+        {0,8,39},{0,9,174},{0,8,7},{0,8,135},{0,8,71},{0,9,238},
+        {128,7,9},{0,8,95},{0,8,31},{0,9,158},{132,7,99},{0,8,127},
+        {0,8,63},{0,9,222},{130,7,27},{0,8,111},{0,8,47},{0,9,190},
+        {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},
+        {0,8,16},{132,8,115},{130,7,31},{0,8,112},{0,8,48},{0,9,193},
+        {128,7,10},{0,8,96},{0,8,32},{0,9,161},{0,8,0},{0,8,128},
+        {0,8,64},{0,9,225},{128,7,6},{0,8,88},{0,8,24},{0,9,145},
+        {131,7,59},{0,8,120},{0,8,56},{0,9,209},{129,7,17},{0,8,104},
+        {0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},{0,9,241},
+        {128,7,4},{0,8,84},{0,8,20},{133,8,227},{131,7,43},{0,8,116},
+        {0,8,52},{0,9,201},{129,7,13},{0,8,100},{0,8,36},{0,9,169},
+        {0,8,4},{0,8,132},{0,8,68},{0,9,233},{128,7,8},{0,8,92},
+        {0,8,28},{0,9,153},{132,7,83},{0,8,124},{0,8,60},{0,9,217},
+        {130,7,23},{0,8,108},{0,8,44},{0,9,185},{0,8,12},{0,8,140},
+        {0,8,76},{0,9,249},{128,7,3},{0,8,82},{0,8,18},{133,8,163},
+        {131,7,35},{0,8,114},{0,8,50},{0,9,197},{129,7,11},{0,8,98},
+        {0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
+        {128,7,7},{0,8,90},{0,8,26},{0,9,149},{132,7,67},{0,8,122},
+        {0,8,58},{0,9,213},{130,7,19},{0,8,106},{0,8,42},{0,9,181},
+        {0,8,10},{0,8,138},{0,8,74},{0,9,245},{128,7,5},{0,8,86},
+        {0,8,22},{65,8,0},{131,7,51},{0,8,118},{0,8,54},{0,9,205},
+        {129,7,15},{0,8,102},{0,8,38},{0,9,173},{0,8,6},{0,8,134},
+        {0,8,70},{0,9,237},{128,7,9},{0,8,94},{0,8,30},{0,9,157},
+        {132,7,99},{0,8,126},{0,8,62},{0,9,221},{130,7,27},{0,8,110},
+        {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},
+        {96,7,0},{0,8,81},{0,8,17},{133,8,131},{130,7,31},{0,8,113},
+        {0,8,49},{0,9,195},{128,7,10},{0,8,97},{0,8,33},{0,9,163},
+        {0,8,1},{0,8,129},{0,8,65},{0,9,227},{128,7,6},{0,8,89},
+        {0,8,25},{0,9,147},{131,7,59},{0,8,121},{0,8,57},{0,9,211},
+        {129,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},{0,8,137},
+        {0,8,73},{0,9,243},{128,7,4},{0,8,85},{0,8,21},{144,8,3},
+        {131,7,43},{0,8,117},{0,8,53},{0,9,203},{129,7,13},{0,8,101},
+        {0,8,37},{0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},
+        {128,7,8},{0,8,93},{0,8,29},{0,9,155},{132,7,83},{0,8,125},
+        {0,8,61},{0,9,219},{130,7,23},{0,8,109},{0,8,45},{0,9,187},
+        {0,8,13},{0,8,141},{0,8,77},{0,9,251},{128,7,3},{0,8,83},
+        {0,8,19},{133,8,195},{131,7,35},{0,8,115},{0,8,51},{0,9,199},
+        {129,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
+        {0,8,67},{0,9,231},{128,7,7},{0,8,91},{0,8,27},{0,9,151},
+        {132,7,67},{0,8,123},{0,8,59},{0,9,215},{130,7,19},{0,8,107},
+        {0,8,43},{0,9,183},{0,8,11},{0,8,139},{0,8,75},{0,9,247},
+        {128,7,5},{0,8,87},{0,8,23},{77,8,0},{131,7,51},{0,8,119},
+        {0,8,55},{0,9,207},{129,7,15},{0,8,103},{0,8,39},{0,9,175},
+        {0,8,7},{0,8,135},{0,8,71},{0,9,239},{128,7,9},{0,8,95},
+        {0,8,31},{0,9,159},{132,7,99},{0,8,127},{0,8,63},{0,9,223},
+        {130,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},
+        {0,8,79},{0,9,255}
+    };
+
+    static const code distfix[32] = {
+        {128,5,1},{135,5,257},{131,5,17},{139,5,4097},{129,5,5},
+        {137,5,1025},{133,5,65},{141,5,16385},{128,5,3},{136,5,513},
+        {132,5,33},{140,5,8193},{130,5,9},{138,5,2049},{134,5,129},
+        {142,5,32769},{128,5,2},{135,5,385},{131,5,25},{139,5,6145},
+        {129,5,7},{137,5,1537},{133,5,97},{141,5,24577},{128,5,4},
+        {136,5,769},{132,5,49},{140,5,12289},{130,5,13},{138,5,3073},
+        {134,5,193},{142,5,49153}
+    };
diff --git a/xs/src/png/zlib/contrib/infback9/inflate9.h b/xs/src/png/zlib/contrib/infback9/inflate9.h
new file mode 100644
index 000000000..ee9a79394
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/inflate9.h
@@ -0,0 +1,47 @@
+/* inflate9.h -- internal inflate state definition
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+            LEN,        /* i: waiting for length/lit code */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD         /* got a data error -- remain here until reset */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to the BAD mode -- not shown for clarity)
+
+    Read deflate blocks:
+            TYPE -> STORED or TABLE or LEN or DONE
+            STORED -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN
+    Read deflate codes:
+                LEN -> LEN or TYPE
+ */
+
+/* state maintained between inflate() calls.  Approximately 7K bytes. */
+struct inflate_state {
+        /* sliding window */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code FAR *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+};
diff --git a/xs/src/png/zlib/contrib/infback9/inftree9.c b/xs/src/png/zlib/contrib/infback9/inftree9.c
new file mode 100644
index 000000000..5f4a76798
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/inftree9.c
@@ -0,0 +1,324 @@
+/* inftree9.c -- generate Huffman trees for efficient decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftree9.h"
+
+#define MAXBITS 15
+
+const char inflate9_copyright[] =
+   " inflate9 1.2.11 Copyright 1995-2017 Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/*
+   Build a set of tables to decode the provided canonical Huffman code.
+   The code lengths are lens[0..codes-1].  The result starts at *table,
+   whose indices are 0..2^bits-1.  work is a writable array of at least
+   lens shorts, which is used as a work area.  type is the type of code
+   to be generated, CODES, LENS, or DISTS.  On return, zero is success,
+   -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
+   on return points to the next available entry's address.  bits is the
+   requested root table index bits, and on return it is the actual root
+   table index bits.  It will differ if the request is greater than the
+   longest code or if it is less than the shortest code.
+ */
+int inflate_table9(type, lens, codes, table, bits, work)
+codetype type;
+unsigned short FAR *lens;
+unsigned codes;
+code FAR * FAR *table;
+unsigned FAR *bits;
+unsigned short FAR *work;
+{
+    unsigned len;               /* a code's length in bits */
+    unsigned sym;               /* index of code symbols */
+    unsigned min, max;          /* minimum and maximum code lengths */
+    unsigned root;              /* number of index bits for root table */
+    unsigned curr;              /* number of index bits for current table */
+    unsigned drop;              /* code bits to drop for sub-table */
+    int left;                   /* number of prefix codes available */
+    unsigned used;              /* code entries in table used */
+    unsigned huff;              /* Huffman code */
+    unsigned incr;              /* for incrementing code, index */
+    unsigned fill;              /* index for replicating entries */
+    unsigned low;               /* low bits for current root entry */
+    unsigned mask;              /* mask for low root bits */
+    code this;                  /* table entry for duplication */
+    code FAR *next;             /* next available space in table */
+    const unsigned short FAR *base;     /* base value table to use */
+    const unsigned short FAR *extra;    /* extra bits table to use */
+    int end;                    /* use base and extra for symbol > end */
+    unsigned short count[MAXBITS+1];    /* number of codes of each length */
+    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
+    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17,
+        19, 23, 27, 31, 35, 43, 51, 59, 67, 83, 99, 115,
+        131, 163, 195, 227, 3, 0, 0};
+    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
+        128, 128, 128, 128, 128, 128, 128, 128, 129, 129, 129, 129,
+        130, 130, 130, 130, 131, 131, 131, 131, 132, 132, 132, 132,
+        133, 133, 133, 133, 144, 77, 202};
+    static const unsigned short dbase[32] = { /* Distance codes 0..31 base */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49,
+        65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049, 3073,
+        4097, 6145, 8193, 12289, 16385, 24577, 32769, 49153};
+    static const unsigned short dext[32] = { /* Distance codes 0..31 extra */
+        128, 128, 128, 128, 129, 129, 130, 130, 131, 131, 132, 132,
+        133, 133, 134, 134, 135, 135, 136, 136, 137, 137, 138, 138,
+        139, 139, 140, 140, 141, 141, 142, 142};
+
+    /*
+       Process a set of code lengths to create a canonical Huffman code.  The
+       code lengths are lens[0..codes-1].  Each length corresponds to the
+       symbols 0..codes-1.  The Huffman code is generated by first sorting the
+       symbols by length from short to long, and retaining the symbol order
+       for codes with equal lengths.  Then the code starts with all zero bits
+       for the first code of the shortest length, and the codes are integer
+       increments for the same length, and zeros are appended as the length
+       increases.  For the deflate format, these bits are stored backwards
+       from their more natural integer increment ordering, and so when the
+       decoding tables are built in the large loop below, the integer codes
+       are incremented backwards.
+
+       This routine assumes, but does not check, that all of the entries in
+       lens[] are in the range 0..MAXBITS.  The caller must assure this.
+       1..MAXBITS is interpreted as that code length.  zero means that that
+       symbol does not occur in this code.
+
+       The codes are sorted by computing a count of codes for each length,
+       creating from that a table of starting indices for each length in the
+       sorted table, and then entering the symbols in order in the sorted
+       table.  The sorted table is work[], with that space being provided by
+       the caller.
+
+       The length counts are used for other purposes as well, i.e. finding
+       the minimum and maximum length codes, determining if there are any
+       codes at all, checking for a valid set of lengths, and looking ahead
+       at length counts to determine sub-table sizes when building the
+       decoding tables.
+     */
+
+    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
+    for (len = 0; len <= MAXBITS; len++)
+        count[len] = 0;
+    for (sym = 0; sym < codes; sym++)
+        count[lens[sym]]++;
+
+    /* bound code lengths, force root to be within code lengths */
+    root = *bits;
+    for (max = MAXBITS; max >= 1; max--)
+        if (count[max] != 0) break;
+    if (root > max) root = max;
+    if (max == 0) return -1;            /* no codes! */
+    for (min = 1; min <= MAXBITS; min++)
+        if (count[min] != 0) break;
+    if (root < min) root = min;
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;
+        left -= count[len];
+        if (left < 0) return -1;        /* over-subscribed */
+    }
+    if (left > 0 && (type == CODES || max != 1))
+        return -1;                      /* incomplete set */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + count[len];
+
+    /* sort symbols by length, by symbol order within each length */
+    for (sym = 0; sym < codes; sym++)
+        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;
+
+    /*
+       Create and fill in decoding tables.  In this loop, the table being
+       filled is at next and has curr index bits.  The code being used is huff
+       with length len.  That code is converted to an index by dropping drop
+       bits off of the bottom.  For codes where len is less than drop + curr,
+       those top drop + curr - len bits are incremented through all values to
+       fill the table with replicated entries.
+
+       root is the number of index bits for the root table.  When len exceeds
+       root, sub-tables are created pointed to by the root entry with an index
+       of the low root bits of huff.  This is saved in low to check for when a
+       new sub-table should be started.  drop is zero when the root table is
+       being filled, and drop is root when sub-tables are being filled.
+
+       When a new sub-table is needed, it is necessary to look ahead in the
+       code lengths to determine what size sub-table is needed.  The length
+       counts are used for this, and so count[] is decremented as codes are
+       entered in the tables.
+
+       used keeps track of how many table entries have been allocated from the
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftree9.h
+       for more information.
+
+       sym increments through all symbols, and the loop terminates when
+       all codes of length max, i.e. all codes, have been processed.  This
+       routine permits incomplete codes, so another loop after this one fills
+       in the rest of the decoding tables with invalid code markers.
+     */
+
+    /* set up for code type */
+    switch (type) {
+    case CODES:
+        base = extra = work;    /* dummy value--not used */
+        end = 19;
+        break;
+    case LENS:
+        base = lbase;
+        base -= 257;
+        extra = lext;
+        extra -= 257;
+        end = 256;
+        break;
+    default:            /* DISTS */
+        base = dbase;
+        extra = dext;
+        end = -1;
+    }
+
+    /* initialize state for loop */
+    huff = 0;                   /* starting code */
+    sym = 0;                    /* starting code symbol */
+    len = min;                  /* starting code length */
+    next = *table;              /* current table to fill in */
+    curr = root;                /* current table index bits */
+    drop = 0;                   /* current bits to drop from code for index */
+    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
+    used = 1U << root;          /* use root table entries */
+    mask = used - 1;            /* mask for comparing low */
+
+    /* check available table space */
+    if ((type == LENS && used >= ENOUGH_LENS) ||
+        (type == DISTS && used >= ENOUGH_DISTS))
+        return 1;
+
+    /* process all codes and make table entries */
+    for (;;) {
+        /* create table entry */
+        this.bits = (unsigned char)(len - drop);
+        if ((int)(work[sym]) < end) {
+            this.op = (unsigned char)0;
+            this.val = work[sym];
+        }
+        else if ((int)(work[sym]) > end) {
+            this.op = (unsigned char)(extra[work[sym]]);
+            this.val = base[work[sym]];
+        }
+        else {
+            this.op = (unsigned char)(32 + 64);         /* end of block */
+            this.val = 0;
+        }
+
+        /* replicate for those indices with low len bits equal to huff */
+        incr = 1U << (len - drop);
+        fill = 1U << curr;
+        do {
+            fill -= incr;
+            next[(huff >> drop) + fill] = this;
+        } while (fill != 0);
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+
+        /* go to next symbol, update count, len */
+        sym++;
+        if (--(count[len]) == 0) {
+            if (len == max) break;
+            len = lens[work[sym]];
+        }
+
+        /* create new sub-table if needed */
+        if (len > root && (huff & mask) != low) {
+            /* if first time, transition to sub-tables */
+            if (drop == 0)
+                drop = root;
+
+            /* increment past last table */
+            next += 1U << curr;
+
+            /* determine length of next table */
+            curr = len - drop;
+            left = (int)(1 << curr);
+            while (curr + drop < max) {
+                left -= count[curr + drop];
+                if (left <= 0) break;
+                curr++;
+                left <<= 1;
+            }
+
+            /* check for enough space */
+            used += 1U << curr;
+            if ((type == LENS && used >= ENOUGH_LENS) ||
+                (type == DISTS && used >= ENOUGH_DISTS))
+                return 1;
+
+            /* point entry in root table to sub-table */
+            low = huff & mask;
+            (*table)[low].op = (unsigned char)curr;
+            (*table)[low].bits = (unsigned char)root;
+            (*table)[low].val = (unsigned short)(next - *table);
+        }
+    }
+
+    /*
+       Fill in rest of table for incomplete codes.  This loop is similar to the
+       loop above in incrementing huff for table indices.  It is assumed that
+       len is equal to curr + drop, so there is no loop needed to increment
+       through high index bits.  When the current sub-table is filled, the loop
+       drops back to the root table to fill in any remaining entries there.
+     */
+    this.op = (unsigned char)64;                /* invalid code marker */
+    this.bits = (unsigned char)(len - drop);
+    this.val = (unsigned short)0;
+    while (huff != 0) {
+        /* when done with sub-table, drop back to root table */
+        if (drop != 0 && (huff & mask) != low) {
+            drop = 0;
+            len = root;
+            next = *table;
+            curr = root;
+            this.bits = (unsigned char)len;
+        }
+
+        /* put invalid code marker in table */
+        next[huff >> drop] = this;
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+    }
+
+    /* set return parameters */
+    *table += used;
+    *bits = root;
+    return 0;
+}
diff --git a/xs/src/png/zlib/contrib/infback9/inftree9.h b/xs/src/png/zlib/contrib/infback9/inftree9.h
new file mode 100644
index 000000000..5ab21f0c6
--- /dev/null
+++ b/xs/src/png/zlib/contrib/infback9/inftree9.h
@@ -0,0 +1,61 @@
+/* inftree9.h -- header to use inftree9.c
+ * Copyright (C) 1995-2008 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Structure for decoding tables.  Each entry provides either the
+   information needed to do the operation requested by the code that
+   indexed that table entry, or it provides a pointer to another
+   table that indexes more bits of the code.  op indicates whether
+   the entry is a pointer to another table, a literal, a length or
+   distance, an end-of-block, or an invalid code.  For a table
+   pointer, the low four bits of op is the number of index bits of
+   that table.  For a length or distance, the low four bits of op
+   is the number of extra bits to get after the code.  bits is
+   the number of bits in this code or part of the code to drop off
+   of the bit buffer.  val is the actual byte to output in the case
+   of a literal, the base length or distance, or the offset from
+   the current table to the next table.  Each entry is four bytes. */
+typedef struct {
+    unsigned char op;           /* operation, extra bits, table bits */
+    unsigned char bits;         /* bits in this part of the code */
+    unsigned short val;         /* offset in table or code value */
+} code;
+
+/* op values as set by inflate_table():
+    00000000 - literal
+    0000tttt - table link, tttt != 0 is the number of table index bits
+    100eeeee - length or distance, eeee is the number of extra bits
+    01100000 - end of block
+    01000000 - invalid code
+ */
+
+/* Maximum size of the dynamic table.  The maximum number of code structures is
+   1446, which is the sum of 852 for literal/length codes and 594 for distance
+   codes.  These values were found by exhaustive searches using the program
+   examples/enough.c found in the zlib distribtution.  The arguments to that
+   program are the number of symbols, the initial root table size, and the
+   maximum bit length of a code.  "enough 286 9 15" for literal/length codes
+   returns returns 852, and "enough 32 6 15" for distance codes returns 594.
+   The initial root table size (9 or 6) is found in the fifth argument of the
+   inflate_table() calls in infback9.c.  If the root table size is changed,
+   then these maximum sizes would be need to be recalculated and updated. */
+#define ENOUGH_LENS 852
+#define ENOUGH_DISTS 594
+#define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
+
+/* Type of code to build for inflate_table9() */
+typedef enum {
+    CODES,
+    LENS,
+    DISTS
+} codetype;
+
+extern int inflate_table9 OF((codetype type, unsigned short FAR *lens,
+                             unsigned codes, code FAR * FAR *table,
+                             unsigned FAR *bits, unsigned short FAR *work));
diff --git a/xs/src/png/zlib/contrib/inflate86/inffas86.c b/xs/src/png/zlib/contrib/inflate86/inffas86.c
new file mode 100644
index 000000000..7292f67b7
--- /dev/null
+++ b/xs/src/png/zlib/contrib/inflate86/inffas86.c
@@ -0,0 +1,1157 @@
+/* inffas86.c is a hand tuned assembler version of
+ *
+ * inffast.c -- fast decoding
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Copyright (C) 2003 Chris Anderson <christop@charm.net>
+ * Please use the copyright conditions above.
+ *
+ * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
+ * slightly quicker on x86 systems because, instead of using rep movsb to copy
+ * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
+ * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
+ * from http://fedora.linux.duke.edu/fc1_x86_64
+ * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
+ * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
+ * when decompressing mozilla-source-1.3.tar.gz.
+ *
+ * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
+ * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
+ * the moment.  I have successfully compiled and tested this code with gcc2.96,
+ * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
+ * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
+ * enabled.  I will attempt to merge the MMX code into this version.  Newer
+ * versions of this and inffast.S can be found at
+ * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+/* Mark Adler's comments from inffast.c: */
+
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
+
+   Entry assumptions:
+
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+void inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
+{
+    struct inflate_state FAR *state;
+    struct inffast_ar {
+/* 64   32                               x86  x86_64 */
+/* ar offset                              register */
+/*  0    0 */ void *esp;                /* esp save */
+/*  8    4 */ void *ebp;                /* ebp save */
+/* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
+/* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
+/* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
+/* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
+/* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
+/* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
+/* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
+/* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
+/* 80   40 */ unsigned long hold;       /* edx rdx  local strm->hold */
+/* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
+/* 92   48 */ unsigned wsize;           /*          window size */
+/* 96   52 */ unsigned write;           /*          window write index */
+/*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
+/*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
+/*108   64 */ unsigned len;             /*     r14  match length */
+/*112   68 */ unsigned dist;            /*     r15  match distance */
+/*116   72 */ unsigned status;          /*          set when state chng*/
+    } ar;
+
+#if defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )
+#define PAD_AVAIL_IN 6
+#define PAD_AVAIL_OUT 258
+#else
+#define PAD_AVAIL_IN 5
+#define PAD_AVAIL_OUT 257
+#endif
+
+    /* copy state to local variables */
+    state = (struct inflate_state FAR *)strm->state;
+    ar.in = strm->next_in;
+    ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
+    ar.out = strm->next_out;
+    ar.beg = ar.out - (start - strm->avail_out);
+    ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
+    ar.wsize = state->wsize;
+    ar.write = state->wnext;
+    ar.window = state->window;
+    ar.hold = state->hold;
+    ar.bits = state->bits;
+    ar.lcode = state->lencode;
+    ar.dcode = state->distcode;
+    ar.lmask = (1U << state->lenbits) - 1;
+    ar.dmask = (1U << state->distbits) - 1;
+
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
+
+    /* align in on 1/2 hold size boundary */
+    while (((unsigned long)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
+        ar.hold += (unsigned long)*ar.in++ << ar.bits;
+        ar.bits += 8;
+    }
+
+#if defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )
+    __asm__ __volatile__ (
+"        leaq    %0, %%rax\n"
+"        movq    %%rbp, 8(%%rax)\n"       /* save regs rbp and rsp */
+"        movq    %%rsp, (%%rax)\n"
+"        movq    %%rax, %%rsp\n"          /* make rsp point to &ar */
+"        movq    16(%%rsp), %%rsi\n"      /* rsi  = in */
+"        movq    32(%%rsp), %%rdi\n"      /* rdi  = out */
+"        movq    24(%%rsp), %%r9\n"       /* r9   = last */
+"        movq    48(%%rsp), %%r10\n"      /* r10  = end */
+"        movq    64(%%rsp), %%rbp\n"      /* rbp  = lcode */
+"        movq    72(%%rsp), %%r11\n"      /* r11  = dcode */
+"        movq    80(%%rsp), %%rdx\n"      /* rdx  = hold */
+"        movl    88(%%rsp), %%ebx\n"      /* ebx  = bits */
+"        movl    100(%%rsp), %%r12d\n"    /* r12d = lmask */
+"        movl    104(%%rsp), %%r13d\n"    /* r13d = dmask */
+                                          /* r14d = len */
+                                          /* r15d = dist */
+"        cld\n"
+"        cmpq    %%rdi, %%r10\n"
+"        je      .L_one_time\n"           /* if only one decode left */
+"        cmpq    %%rsi, %%r9\n"
+"        je      .L_one_time\n"
+"        jmp     .L_do_loop\n"
+
+".L_one_time:\n"
+"        movq    %%r12, %%r8\n"           /* r8 = lmask */
+"        cmpb    $32, %%bl\n"
+"        ja      .L_get_length_code_one_time\n"
+
+"        lodsl\n"                         /* eax = *(uint *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $32, %%bl\n"             /* bits += 32 */
+"        shlq    %%cl, %%rax\n"
+"        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
+"        jmp     .L_get_length_code_one_time\n"
+
+".align 32,0x90\n"
+".L_while_test:\n"
+"        cmpq    %%rdi, %%r10\n"
+"        jbe     .L_break_loop\n"
+"        cmpq    %%rsi, %%r9\n"
+"        jbe     .L_break_loop\n"
+
+".L_do_loop:\n"
+"        movq    %%r12, %%r8\n"           /* r8 = lmask */
+"        cmpb    $32, %%bl\n"
+"        ja      .L_get_length_code\n"    /* if (32 < bits) */
+
+"        lodsl\n"                         /* eax = *(uint *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $32, %%bl\n"             /* bits += 32 */
+"        shlq    %%cl, %%rax\n"
+"        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
+
+".L_get_length_code:\n"
+"        andq    %%rdx, %%r8\n"            /* r8 &= hold */
+"        movl    (%%rbp,%%r8,4), %%eax\n"  /* eax = lcode[hold & lmask] */
+
+"        movb    %%ah, %%cl\n"            /* cl = this.bits */
+"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
+"        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
+
+"        testb   %%al, %%al\n"
+"        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */
+
+"        movq    %%r12, %%r8\n"            /* r8 = lmask */
+"        shrl    $16, %%eax\n"            /* output this.val char */
+"        stosb\n"
+
+".L_get_length_code_one_time:\n"
+"        andq    %%rdx, %%r8\n"            /* r8 &= hold */
+"        movl    (%%rbp,%%r8,4), %%eax\n" /* eax = lcode[hold & lmask] */
+
+".L_dolen:\n"
+"        movb    %%ah, %%cl\n"            /* cl = this.bits */
+"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
+"        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
+
+"        testb   %%al, %%al\n"
+"        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */
+
+"        shrl    $16, %%eax\n"            /* output this.val char */
+"        stosb\n"
+"        jmp     .L_while_test\n"
+
+".align 32,0x90\n"
+".L_test_for_length_base:\n"
+"        movl    %%eax, %%r14d\n"         /* len = this */
+"        shrl    $16, %%r14d\n"           /* len = this.val */
+"        movb    %%al, %%cl\n"
+
+"        testb   $16, %%al\n"
+"        jz      .L_test_for_second_level_length\n" /* if ((op & 16) == 0) 8% */
+"        andb    $15, %%cl\n"             /* op &= 15 */
+"        jz      .L_decode_distance\n"    /* if (!op) */
+
+".L_add_bits_to_len:\n"
+"        subb    %%cl, %%bl\n"
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"
+"        andl    %%edx, %%eax\n"          /* eax &= hold */
+"        shrq    %%cl, %%rdx\n"
+"        addl    %%eax, %%r14d\n"         /* len += hold & mask[op] */
+
+".L_decode_distance:\n"
+"        movq    %%r13, %%r8\n"           /* r8 = dmask */
+"        cmpb    $32, %%bl\n"
+"        ja      .L_get_distance_code\n"  /* if (32 < bits) */
+
+"        lodsl\n"                         /* eax = *(uint *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $32, %%bl\n"             /* bits += 32 */
+"        shlq    %%cl, %%rax\n"
+"        orq     %%rax, %%rdx\n"          /* hold |= *((uint *)in)++ << bits */
+
+".L_get_distance_code:\n"
+"        andq    %%rdx, %%r8\n"           /* r8 &= hold */
+"        movl    (%%r11,%%r8,4), %%eax\n" /* eax = dcode[hold & dmask] */
+
+".L_dodist:\n"
+"        movl    %%eax, %%r15d\n"         /* dist = this */
+"        shrl    $16, %%r15d\n"           /* dist = this.val */
+"        movb    %%ah, %%cl\n"
+"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
+"        shrq    %%cl, %%rdx\n"           /* hold >>= this.bits */
+"        movb    %%al, %%cl\n"            /* cl = this.op */
+
+"        testb   $16, %%al\n"             /* if ((op & 16) == 0) */
+"        jz      .L_test_for_second_level_dist\n"
+"        andb    $15, %%cl\n"             /* op &= 15 */
+"        jz      .L_check_dist_one\n"
+
+".L_add_bits_to_dist:\n"
+"        subb    %%cl, %%bl\n"
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"                 /* (1 << op) - 1 */
+"        andl    %%edx, %%eax\n"          /* eax &= hold */
+"        shrq    %%cl, %%rdx\n"
+"        addl    %%eax, %%r15d\n"         /* dist += hold & ((1 << op) - 1) */
+
+".L_check_window:\n"
+"        movq    %%rsi, %%r8\n"           /* save in so from can use it's reg */
+"        movq    %%rdi, %%rax\n"
+"        subq    40(%%rsp), %%rax\n"      /* nbytes = out - beg */
+
+"        cmpl    %%r15d, %%eax\n"
+"        jb      .L_clip_window\n"        /* if (dist > nbytes) 4.2% */
+
+"        movl    %%r14d, %%ecx\n"         /* ecx = len */
+"        movq    %%rdi, %%rsi\n"
+"        subq    %%r15, %%rsi\n"          /* from = out - dist */
+
+"        sarl    %%ecx\n"
+"        jnc     .L_copy_two\n"           /* if len % 2 == 0 */
+
+"        rep     movsw\n"
+"        movb    (%%rsi), %%al\n"
+"        movb    %%al, (%%rdi)\n"
+"        incq    %%rdi\n"
+
+"        movq    %%r8, %%rsi\n"           /* move in back to %rsi, toss from */
+"        jmp     .L_while_test\n"
+
+".L_copy_two:\n"
+"        rep     movsw\n"
+"        movq    %%r8, %%rsi\n"           /* move in back to %rsi, toss from */
+"        jmp     .L_while_test\n"
+
+".align 32,0x90\n"
+".L_check_dist_one:\n"
+"        cmpl    $1, %%r15d\n"            /* if dist 1, is a memset */
+"        jne     .L_check_window\n"
+"        cmpq    %%rdi, 40(%%rsp)\n"      /* if out == beg, outside window */
+"        je      .L_check_window\n"
+
+"        movl    %%r14d, %%ecx\n"         /* ecx = len */
+"        movb    -1(%%rdi), %%al\n"
+"        movb    %%al, %%ah\n"
+
+"        sarl    %%ecx\n"
+"        jnc     .L_set_two\n"
+"        movb    %%al, (%%rdi)\n"
+"        incq    %%rdi\n"
+
+".L_set_two:\n"
+"        rep     stosw\n"
+"        jmp     .L_while_test\n"
+
+".align 32,0x90\n"
+".L_test_for_second_level_length:\n"
+"        testb   $64, %%al\n"
+"        jnz     .L_test_for_end_of_block\n" /* if ((op & 64) != 0) */
+
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"
+"        andl    %%edx, %%eax\n"         /* eax &= hold */
+"        addl    %%r14d, %%eax\n"        /* eax += len */
+"        movl    (%%rbp,%%rax,4), %%eax\n" /* eax = lcode[val+(hold&mask[op])]*/
+"        jmp     .L_dolen\n"
+
+".align 32,0x90\n"
+".L_test_for_second_level_dist:\n"
+"        testb   $64, %%al\n"
+"        jnz     .L_invalid_distance_code\n" /* if ((op & 64) != 0) */
+
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"
+"        andl    %%edx, %%eax\n"         /* eax &= hold */
+"        addl    %%r15d, %%eax\n"        /* eax += dist */
+"        movl    (%%r11,%%rax,4), %%eax\n" /* eax = dcode[val+(hold&mask[op])]*/
+"        jmp     .L_dodist\n"
+
+".align 32,0x90\n"
+".L_clip_window:\n"
+"        movl    %%eax, %%ecx\n"         /* ecx = nbytes */
+"        movl    92(%%rsp), %%eax\n"     /* eax = wsize, prepare for dist cmp */
+"        negl    %%ecx\n"                /* nbytes = -nbytes */
+
+"        cmpl    %%r15d, %%eax\n"
+"        jb      .L_invalid_distance_too_far\n" /* if (dist > wsize) */
+
+"        addl    %%r15d, %%ecx\n"         /* nbytes = dist - nbytes */
+"        cmpl    $0, 96(%%rsp)\n"
+"        jne     .L_wrap_around_window\n" /* if (write != 0) */
+
+"        movq    56(%%rsp), %%rsi\n"     /* from  = window */
+"        subl    %%ecx, %%eax\n"         /* eax  -= nbytes */
+"        addq    %%rax, %%rsi\n"         /* from += wsize - nbytes */
+
+"        movl    %%r14d, %%eax\n"        /* eax = len */
+"        cmpl    %%ecx, %%r14d\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* eax -= nbytes */
+"        rep     movsb\n"
+"        movq    %%rdi, %%rsi\n"
+"        subq    %%r15, %%rsi\n"         /* from = &out[ -dist ] */
+"        jmp     .L_do_copy\n"
+
+".align 32,0x90\n"
+".L_wrap_around_window:\n"
+"        movl    96(%%rsp), %%eax\n"     /* eax = write */
+"        cmpl    %%eax, %%ecx\n"
+"        jbe     .L_contiguous_in_window\n" /* if (write >= nbytes) */
+
+"        movl    92(%%rsp), %%esi\n"     /* from  = wsize */
+"        addq    56(%%rsp), %%rsi\n"     /* from += window */
+"        addq    %%rax, %%rsi\n"         /* from += write */
+"        subq    %%rcx, %%rsi\n"         /* from -= nbytes */
+"        subl    %%eax, %%ecx\n"         /* nbytes -= write */
+
+"        movl    %%r14d, %%eax\n"        /* eax = len */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movq    56(%%rsp), %%rsi\n"     /* from = window */
+"        movl    96(%%rsp), %%ecx\n"     /* nbytes = write */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movq    %%rdi, %%rsi\n"
+"        subq    %%r15, %%rsi\n"         /* from = out - dist */
+"        jmp     .L_do_copy\n"
+
+".align 32,0x90\n"
+".L_contiguous_in_window:\n"
+"        movq    56(%%rsp), %%rsi\n"     /* rsi = window */
+"        addq    %%rax, %%rsi\n"
+"        subq    %%rcx, %%rsi\n"         /* from += write - nbytes */
+
+"        movl    %%r14d, %%eax\n"        /* eax = len */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movq    %%rdi, %%rsi\n"
+"        subq    %%r15, %%rsi\n"         /* from = out - dist */
+"        jmp     .L_do_copy\n"           /* if (nbytes >= len) */
+
+".align 32,0x90\n"
+".L_do_copy:\n"
+"        movl    %%eax, %%ecx\n"         /* ecx = len */
+"        rep     movsb\n"
+
+"        movq    %%r8, %%rsi\n"          /* move in back to %esi, toss from */
+"        jmp     .L_while_test\n"
+
+".L_test_for_end_of_block:\n"
+"        testb   $32, %%al\n"
+"        jz      .L_invalid_literal_length_code\n"
+"        movl    $1, 116(%%rsp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_invalid_literal_length_code:\n"
+"        movl    $2, 116(%%rsp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_invalid_distance_code:\n"
+"        movl    $3, 116(%%rsp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_invalid_distance_too_far:\n"
+"        movl    $4, 116(%%rsp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_break_loop:\n"
+"        movl    $0, 116(%%rsp)\n"
+
+".L_break_loop_with_status:\n"
+/* put in, out, bits, and hold back into ar and pop esp */
+"        movq    %%rsi, 16(%%rsp)\n"     /* in */
+"        movq    %%rdi, 32(%%rsp)\n"     /* out */
+"        movl    %%ebx, 88(%%rsp)\n"     /* bits */
+"        movq    %%rdx, 80(%%rsp)\n"     /* hold */
+"        movq    (%%rsp), %%rax\n"       /* restore rbp and rsp */
+"        movq    8(%%rsp), %%rbp\n"
+"        movq    %%rax, %%rsp\n"
+          :
+          : "m" (ar)
+          : "memory", "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi",
+            "%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
+    );
+#elif ( defined( __GNUC__ ) || defined( __ICC ) ) && defined( __i386 )
+    __asm__ __volatile__ (
+"        leal    %0, %%eax\n"
+"        movl    %%esp, (%%eax)\n"        /* save esp, ebp */
+"        movl    %%ebp, 4(%%eax)\n"
+"        movl    %%eax, %%esp\n"
+"        movl    8(%%esp), %%esi\n"       /* esi = in */
+"        movl    16(%%esp), %%edi\n"      /* edi = out */
+"        movl    40(%%esp), %%edx\n"      /* edx = hold */
+"        movl    44(%%esp), %%ebx\n"      /* ebx = bits */
+"        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
+
+"        cld\n"
+"        jmp     .L_do_loop\n"
+
+".align 32,0x90\n"
+".L_while_test:\n"
+"        cmpl    %%edi, 24(%%esp)\n"      /* out < end */
+"        jbe     .L_break_loop\n"
+"        cmpl    %%esi, 12(%%esp)\n"      /* in < last */
+"        jbe     .L_break_loop\n"
+
+".L_do_loop:\n"
+"        cmpb    $15, %%bl\n"
+"        ja      .L_get_length_code\n"    /* if (15 < bits) */
+
+"        xorl    %%eax, %%eax\n"
+"        lodsw\n"                         /* al = *(ushort *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $16, %%bl\n"             /* bits += 16 */
+"        shll    %%cl, %%eax\n"
+"        orl     %%eax, %%edx\n"        /* hold |= *((ushort *)in)++ << bits */
+
+".L_get_length_code:\n"
+"        movl    56(%%esp), %%eax\n"      /* eax = lmask */
+"        andl    %%edx, %%eax\n"          /* eax &= hold */
+"        movl    (%%ebp,%%eax,4), %%eax\n" /* eax = lcode[hold & lmask] */
+
+".L_dolen:\n"
+"        movb    %%ah, %%cl\n"            /* cl = this.bits */
+"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
+"        shrl    %%cl, %%edx\n"           /* hold >>= this.bits */
+
+"        testb   %%al, %%al\n"
+"        jnz     .L_test_for_length_base\n" /* if (op != 0) 45.7% */
+
+"        shrl    $16, %%eax\n"            /* output this.val char */
+"        stosb\n"
+"        jmp     .L_while_test\n"
+
+".align 32,0x90\n"
+".L_test_for_length_base:\n"
+"        movl    %%eax, %%ecx\n"          /* len = this */
+"        shrl    $16, %%ecx\n"            /* len = this.val */
+"        movl    %%ecx, 64(%%esp)\n"      /* save len */
+"        movb    %%al, %%cl\n"
+
+"        testb   $16, %%al\n"
+"        jz      .L_test_for_second_level_length\n" /* if ((op & 16) == 0) 8% */
+"        andb    $15, %%cl\n"             /* op &= 15 */
+"        jz      .L_decode_distance\n"    /* if (!op) */
+"        cmpb    %%cl, %%bl\n"
+"        jae     .L_add_bits_to_len\n"    /* if (op <= bits) */
+
+"        movb    %%cl, %%ch\n"            /* stash op in ch, freeing cl */
+"        xorl    %%eax, %%eax\n"
+"        lodsw\n"                         /* al = *(ushort *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $16, %%bl\n"             /* bits += 16 */
+"        shll    %%cl, %%eax\n"
+"        orl     %%eax, %%edx\n"         /* hold |= *((ushort *)in)++ << bits */
+"        movb    %%ch, %%cl\n"            /* move op back to ecx */
+
+".L_add_bits_to_len:\n"
+"        subb    %%cl, %%bl\n"
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"
+"        andl    %%edx, %%eax\n"          /* eax &= hold */
+"        shrl    %%cl, %%edx\n"
+"        addl    %%eax, 64(%%esp)\n"      /* len += hold & mask[op] */
+
+".L_decode_distance:\n"
+"        cmpb    $15, %%bl\n"
+"        ja      .L_get_distance_code\n"  /* if (15 < bits) */
+
+"        xorl    %%eax, %%eax\n"
+"        lodsw\n"                         /* al = *(ushort *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $16, %%bl\n"             /* bits += 16 */
+"        shll    %%cl, %%eax\n"
+"        orl     %%eax, %%edx\n"         /* hold |= *((ushort *)in)++ << bits */
+
+".L_get_distance_code:\n"
+"        movl    60(%%esp), %%eax\n"      /* eax = dmask */
+"        movl    36(%%esp), %%ecx\n"      /* ecx = dcode */
+"        andl    %%edx, %%eax\n"          /* eax &= hold */
+"        movl    (%%ecx,%%eax,4), %%eax\n"/* eax = dcode[hold & dmask] */
+
+".L_dodist:\n"
+"        movl    %%eax, %%ebp\n"          /* dist = this */
+"        shrl    $16, %%ebp\n"            /* dist = this.val */
+"        movb    %%ah, %%cl\n"
+"        subb    %%ah, %%bl\n"            /* bits -= this.bits */
+"        shrl    %%cl, %%edx\n"           /* hold >>= this.bits */
+"        movb    %%al, %%cl\n"            /* cl = this.op */
+
+"        testb   $16, %%al\n"             /* if ((op & 16) == 0) */
+"        jz      .L_test_for_second_level_dist\n"
+"        andb    $15, %%cl\n"             /* op &= 15 */
+"        jz      .L_check_dist_one\n"
+"        cmpb    %%cl, %%bl\n"
+"        jae     .L_add_bits_to_dist\n"   /* if (op <= bits) 97.6% */
+
+"        movb    %%cl, %%ch\n"            /* stash op in ch, freeing cl */
+"        xorl    %%eax, %%eax\n"
+"        lodsw\n"                         /* al = *(ushort *)in++ */
+"        movb    %%bl, %%cl\n"            /* cl = bits, needs it for shifting */
+"        addb    $16, %%bl\n"             /* bits += 16 */
+"        shll    %%cl, %%eax\n"
+"        orl     %%eax, %%edx\n"        /* hold |= *((ushort *)in)++ << bits */
+"        movb    %%ch, %%cl\n"            /* move op back to ecx */
+
+".L_add_bits_to_dist:\n"
+"        subb    %%cl, %%bl\n"
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"                 /* (1 << op) - 1 */
+"        andl    %%edx, %%eax\n"          /* eax &= hold */
+"        shrl    %%cl, %%edx\n"
+"        addl    %%eax, %%ebp\n"          /* dist += hold & ((1 << op) - 1) */
+
+".L_check_window:\n"
+"        movl    %%esi, 8(%%esp)\n"       /* save in so from can use it's reg */
+"        movl    %%edi, %%eax\n"
+"        subl    20(%%esp), %%eax\n"      /* nbytes = out - beg */
+
+"        cmpl    %%ebp, %%eax\n"
+"        jb      .L_clip_window\n"        /* if (dist > nbytes) 4.2% */
+
+"        movl    64(%%esp), %%ecx\n"      /* ecx = len */
+"        movl    %%edi, %%esi\n"
+"        subl    %%ebp, %%esi\n"          /* from = out - dist */
+
+"        sarl    %%ecx\n"
+"        jnc     .L_copy_two\n"           /* if len % 2 == 0 */
+
+"        rep     movsw\n"
+"        movb    (%%esi), %%al\n"
+"        movb    %%al, (%%edi)\n"
+"        incl    %%edi\n"
+
+"        movl    8(%%esp), %%esi\n"       /* move in back to %esi, toss from */
+"        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
+"        jmp     .L_while_test\n"
+
+".L_copy_two:\n"
+"        rep     movsw\n"
+"        movl    8(%%esp), %%esi\n"       /* move in back to %esi, toss from */
+"        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
+"        jmp     .L_while_test\n"
+
+".align 32,0x90\n"
+".L_check_dist_one:\n"
+"        cmpl    $1, %%ebp\n"            /* if dist 1, is a memset */
+"        jne     .L_check_window\n"
+"        cmpl    %%edi, 20(%%esp)\n"
+"        je      .L_check_window\n"      /* out == beg, if outside window */
+
+"        movl    64(%%esp), %%ecx\n"      /* ecx = len */
+"        movb    -1(%%edi), %%al\n"
+"        movb    %%al, %%ah\n"
+
+"        sarl    %%ecx\n"
+"        jnc     .L_set_two\n"
+"        movb    %%al, (%%edi)\n"
+"        incl    %%edi\n"
+
+".L_set_two:\n"
+"        rep     stosw\n"
+"        movl    32(%%esp), %%ebp\n"      /* ebp = lcode */
+"        jmp     .L_while_test\n"
+
+".align 32,0x90\n"
+".L_test_for_second_level_length:\n"
+"        testb   $64, %%al\n"
+"        jnz     .L_test_for_end_of_block\n" /* if ((op & 64) != 0) */
+
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"
+"        andl    %%edx, %%eax\n"         /* eax &= hold */
+"        addl    64(%%esp), %%eax\n"     /* eax += len */
+"        movl    (%%ebp,%%eax,4), %%eax\n" /* eax = lcode[val+(hold&mask[op])]*/
+"        jmp     .L_dolen\n"
+
+".align 32,0x90\n"
+".L_test_for_second_level_dist:\n"
+"        testb   $64, %%al\n"
+"        jnz     .L_invalid_distance_code\n" /* if ((op & 64) != 0) */
+
+"        xorl    %%eax, %%eax\n"
+"        incl    %%eax\n"
+"        shll    %%cl, %%eax\n"
+"        decl    %%eax\n"
+"        andl    %%edx, %%eax\n"         /* eax &= hold */
+"        addl    %%ebp, %%eax\n"         /* eax += dist */
+"        movl    36(%%esp), %%ecx\n"     /* ecx = dcode */
+"        movl    (%%ecx,%%eax,4), %%eax\n" /* eax = dcode[val+(hold&mask[op])]*/
+"        jmp     .L_dodist\n"
+
+".align 32,0x90\n"
+".L_clip_window:\n"
+"        movl    %%eax, %%ecx\n"
+"        movl    48(%%esp), %%eax\n"     /* eax = wsize */
+"        negl    %%ecx\n"                /* nbytes = -nbytes */
+"        movl    28(%%esp), %%esi\n"     /* from = window */
+
+"        cmpl    %%ebp, %%eax\n"
+"        jb      .L_invalid_distance_too_far\n" /* if (dist > wsize) */
+
+"        addl    %%ebp, %%ecx\n"         /* nbytes = dist - nbytes */
+"        cmpl    $0, 52(%%esp)\n"
+"        jne     .L_wrap_around_window\n" /* if (write != 0) */
+
+"        subl    %%ecx, %%eax\n"
+"        addl    %%eax, %%esi\n"         /* from += wsize - nbytes */
+
+"        movl    64(%%esp), %%eax\n"     /* eax = len */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movl    %%edi, %%esi\n"
+"        subl    %%ebp, %%esi\n"         /* from = out - dist */
+"        jmp     .L_do_copy\n"
+
+".align 32,0x90\n"
+".L_wrap_around_window:\n"
+"        movl    52(%%esp), %%eax\n"     /* eax = write */
+"        cmpl    %%eax, %%ecx\n"
+"        jbe     .L_contiguous_in_window\n" /* if (write >= nbytes) */
+
+"        addl    48(%%esp), %%esi\n"     /* from += wsize */
+"        addl    %%eax, %%esi\n"         /* from += write */
+"        subl    %%ecx, %%esi\n"         /* from -= nbytes */
+"        subl    %%eax, %%ecx\n"         /* nbytes -= write */
+
+"        movl    64(%%esp), %%eax\n"     /* eax = len */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movl    28(%%esp), %%esi\n"     /* from = window */
+"        movl    52(%%esp), %%ecx\n"     /* nbytes = write */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movl    %%edi, %%esi\n"
+"        subl    %%ebp, %%esi\n"         /* from = out - dist */
+"        jmp     .L_do_copy\n"
+
+".align 32,0x90\n"
+".L_contiguous_in_window:\n"
+"        addl    %%eax, %%esi\n"
+"        subl    %%ecx, %%esi\n"         /* from += write - nbytes */
+
+"        movl    64(%%esp), %%eax\n"     /* eax = len */
+"        cmpl    %%ecx, %%eax\n"
+"        jbe     .L_do_copy\n"           /* if (nbytes >= len) */
+
+"        subl    %%ecx, %%eax\n"         /* len -= nbytes */
+"        rep     movsb\n"
+"        movl    %%edi, %%esi\n"
+"        subl    %%ebp, %%esi\n"         /* from = out - dist */
+"        jmp     .L_do_copy\n"           /* if (nbytes >= len) */
+
+".align 32,0x90\n"
+".L_do_copy:\n"
+"        movl    %%eax, %%ecx\n"
+"        rep     movsb\n"
+
+"        movl    8(%%esp), %%esi\n"      /* move in back to %esi, toss from */
+"        movl    32(%%esp), %%ebp\n"     /* ebp = lcode */
+"        jmp     .L_while_test\n"
+
+".L_test_for_end_of_block:\n"
+"        testb   $32, %%al\n"
+"        jz      .L_invalid_literal_length_code\n"
+"        movl    $1, 72(%%esp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_invalid_literal_length_code:\n"
+"        movl    $2, 72(%%esp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_invalid_distance_code:\n"
+"        movl    $3, 72(%%esp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_invalid_distance_too_far:\n"
+"        movl    8(%%esp), %%esi\n"
+"        movl    $4, 72(%%esp)\n"
+"        jmp     .L_break_loop_with_status\n"
+
+".L_break_loop:\n"
+"        movl    $0, 72(%%esp)\n"
+
+".L_break_loop_with_status:\n"
+/* put in, out, bits, and hold back into ar and pop esp */
+"        movl    %%esi, 8(%%esp)\n"      /* save in */
+"        movl    %%edi, 16(%%esp)\n"     /* save out */
+"        movl    %%ebx, 44(%%esp)\n"     /* save bits */
+"        movl    %%edx, 40(%%esp)\n"     /* save hold */
+"        movl    4(%%esp), %%ebp\n"      /* restore esp, ebp */
+"        movl    (%%esp), %%esp\n"
+          :
+          : "m" (ar)
+          : "memory", "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi"
+    );
+#elif defined( _MSC_VER ) && ! defined( _M_AMD64 )
+    __asm {
+	lea	eax, ar
+	mov	[eax], esp         /* save esp, ebp */
+	mov	[eax+4], ebp
+	mov	esp, eax
+	mov	esi, [esp+8]       /* esi = in */
+	mov	edi, [esp+16]      /* edi = out */
+	mov	edx, [esp+40]      /* edx = hold */
+	mov	ebx, [esp+44]      /* ebx = bits */
+	mov	ebp, [esp+32]      /* ebp = lcode */
+
+	cld
+	jmp	L_do_loop
+
+ALIGN 4
+L_while_test:
+	cmp	[esp+24], edi
+	jbe	L_break_loop
+	cmp	[esp+12], esi
+	jbe	L_break_loop
+
+L_do_loop:
+	cmp	bl, 15
+	ja	L_get_length_code    /* if (15 < bits) */
+
+	xor	eax, eax
+	lodsw                         /* al = *(ushort *)in++ */
+	mov	cl, bl            /* cl = bits, needs it for shifting */
+	add	bl, 16             /* bits += 16 */
+	shl	eax, cl
+	or	edx, eax        /* hold |= *((ushort *)in)++ << bits */
+
+L_get_length_code:
+	mov	eax, [esp+56]      /* eax = lmask */
+	and	eax, edx          /* eax &= hold */
+	mov	eax, [ebp+eax*4] /* eax = lcode[hold & lmask] */
+
+L_dolen:
+	mov	cl, ah            /* cl = this.bits */
+	sub	bl, ah            /* bits -= this.bits */
+	shr	edx, cl           /* hold >>= this.bits */
+
+	test	al, al
+	jnz	L_test_for_length_base /* if (op != 0) 45.7% */
+
+	shr	eax, 16            /* output this.val char */
+	stosb
+	jmp	L_while_test
+
+ALIGN 4
+L_test_for_length_base:
+	mov	ecx, eax          /* len = this */
+	shr	ecx, 16            /* len = this.val */
+	mov	[esp+64], ecx      /* save len */
+	mov	cl, al
+
+	test	al, 16
+	jz	L_test_for_second_level_length /* if ((op & 16) == 0) 8% */
+	and	cl, 15             /* op &= 15 */
+	jz	L_decode_distance    /* if (!op) */
+	cmp	bl, cl
+	jae	L_add_bits_to_len    /* if (op <= bits) */
+
+	mov	ch, cl            /* stash op in ch, freeing cl */
+	xor	eax, eax
+	lodsw                         /* al = *(ushort *)in++ */
+	mov	cl, bl            /* cl = bits, needs it for shifting */
+	add	bl, 16             /* bits += 16 */
+	shl	eax, cl
+	or	edx, eax         /* hold |= *((ushort *)in)++ << bits */
+	mov	cl, ch            /* move op back to ecx */
+
+L_add_bits_to_len:
+	sub	bl, cl
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx          /* eax &= hold */
+	shr	edx, cl
+	add	[esp+64], eax      /* len += hold & mask[op] */
+
+L_decode_distance:
+	cmp	bl, 15
+	ja	L_get_distance_code  /* if (15 < bits) */
+
+	xor	eax, eax
+	lodsw                         /* al = *(ushort *)in++ */
+	mov	cl, bl            /* cl = bits, needs it for shifting */
+	add	bl, 16             /* bits += 16 */
+	shl	eax, cl
+	or	edx, eax         /* hold |= *((ushort *)in)++ << bits */
+
+L_get_distance_code:
+	mov	eax, [esp+60]      /* eax = dmask */
+	mov	ecx, [esp+36]      /* ecx = dcode */
+	and	eax, edx          /* eax &= hold */
+	mov	eax, [ecx+eax*4]/* eax = dcode[hold & dmask] */
+
+L_dodist:
+	mov	ebp, eax          /* dist = this */
+	shr	ebp, 16            /* dist = this.val */
+	mov	cl, ah
+	sub	bl, ah            /* bits -= this.bits */
+	shr	edx, cl           /* hold >>= this.bits */
+	mov	cl, al            /* cl = this.op */
+
+	test	al, 16             /* if ((op & 16) == 0) */
+	jz	L_test_for_second_level_dist
+	and	cl, 15             /* op &= 15 */
+	jz	L_check_dist_one
+	cmp	bl, cl
+	jae	L_add_bits_to_dist   /* if (op <= bits) 97.6% */
+
+	mov	ch, cl            /* stash op in ch, freeing cl */
+	xor	eax, eax
+	lodsw                         /* al = *(ushort *)in++ */
+	mov	cl, bl            /* cl = bits, needs it for shifting */
+	add	bl, 16             /* bits += 16 */
+	shl	eax, cl
+	or	edx, eax        /* hold |= *((ushort *)in)++ << bits */
+	mov	cl, ch            /* move op back to ecx */
+
+L_add_bits_to_dist:
+	sub	bl, cl
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax                 /* (1 << op) - 1 */
+	and	eax, edx          /* eax &= hold */
+	shr	edx, cl
+	add	ebp, eax          /* dist += hold & ((1 << op) - 1) */
+
+L_check_window:
+	mov	[esp+8], esi       /* save in so from can use it's reg */
+	mov	eax, edi
+	sub	eax, [esp+20]      /* nbytes = out - beg */
+
+	cmp	eax, ebp
+	jb	L_clip_window        /* if (dist > nbytes) 4.2% */
+
+	mov	ecx, [esp+64]      /* ecx = len */
+	mov	esi, edi
+	sub	esi, ebp          /* from = out - dist */
+
+	sar	ecx, 1
+	jnc	L_copy_two
+
+	rep     movsw
+	mov	al, [esi]
+	mov	[edi], al
+	inc	edi
+
+	mov	esi, [esp+8]      /* move in back to %esi, toss from */
+	mov	ebp, [esp+32]     /* ebp = lcode */
+	jmp	L_while_test
+
+L_copy_two:
+	rep     movsw
+	mov	esi, [esp+8]      /* move in back to %esi, toss from */
+	mov	ebp, [esp+32]     /* ebp = lcode */
+	jmp	L_while_test
+
+ALIGN 4
+L_check_dist_one:
+	cmp	ebp, 1            /* if dist 1, is a memset */
+	jne	L_check_window
+	cmp	[esp+20], edi
+	je	L_check_window    /* out == beg, if outside window */
+
+	mov	ecx, [esp+64]     /* ecx = len */
+	mov	al, [edi-1]
+	mov	ah, al
+
+	sar	ecx, 1
+	jnc	L_set_two
+	mov	[edi], al         /* memset out with from[-1] */
+	inc	edi
+
+L_set_two:
+	rep     stosw
+	mov	ebp, [esp+32]     /* ebp = lcode */
+	jmp	L_while_test
+
+ALIGN 4
+L_test_for_second_level_length:
+	test	al, 64
+	jnz	L_test_for_end_of_block /* if ((op & 64) != 0) */
+
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx         /* eax &= hold */
+	add	eax, [esp+64]     /* eax += len */
+	mov	eax, [ebp+eax*4] /* eax = lcode[val+(hold&mask[op])]*/
+	jmp	L_dolen
+
+ALIGN 4
+L_test_for_second_level_dist:
+	test	al, 64
+	jnz	L_invalid_distance_code /* if ((op & 64) != 0) */
+
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx         /* eax &= hold */
+	add	eax, ebp         /* eax += dist */
+	mov	ecx, [esp+36]     /* ecx = dcode */
+	mov	eax, [ecx+eax*4] /* eax = dcode[val+(hold&mask[op])]*/
+	jmp	L_dodist
+
+ALIGN 4
+L_clip_window:
+	mov	ecx, eax
+	mov	eax, [esp+48]     /* eax = wsize */
+	neg	ecx                /* nbytes = -nbytes */
+	mov	esi, [esp+28]     /* from = window */
+
+	cmp	eax, ebp
+	jb	L_invalid_distance_too_far /* if (dist > wsize) */
+
+	add	ecx, ebp         /* nbytes = dist - nbytes */
+	cmp	dword ptr [esp+52], 0
+	jne	L_wrap_around_window /* if (write != 0) */
+
+	sub	eax, ecx
+	add	esi, eax         /* from += wsize - nbytes */
+
+	mov	eax, [esp+64]    /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy          /* if (nbytes >= len) */
+
+	sub	eax, ecx         /* len -= nbytes */
+	rep     movsb
+	mov	esi, edi
+	sub	esi, ebp         /* from = out - dist */
+	jmp	L_do_copy
+
+ALIGN 4
+L_wrap_around_window:
+	mov	eax, [esp+52]    /* eax = write */
+	cmp	ecx, eax
+	jbe	L_contiguous_in_window /* if (write >= nbytes) */
+
+	add	esi, [esp+48]    /* from += wsize */
+	add	esi, eax         /* from += write */
+	sub	esi, ecx         /* from -= nbytes */
+	sub	ecx, eax         /* nbytes -= write */
+
+	mov	eax, [esp+64]    /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy          /* if (nbytes >= len) */
+
+	sub	eax, ecx         /* len -= nbytes */
+	rep     movsb
+	mov	esi, [esp+28]     /* from = window */
+	mov	ecx, [esp+52]     /* nbytes = write */
+	cmp	eax, ecx
+	jbe	L_do_copy          /* if (nbytes >= len) */
+
+	sub	eax, ecx         /* len -= nbytes */
+	rep     movsb
+	mov	esi, edi
+	sub	esi, ebp         /* from = out - dist */
+	jmp	L_do_copy
+
+ALIGN 4
+L_contiguous_in_window:
+	add	esi, eax
+	sub	esi, ecx         /* from += write - nbytes */
+
+	mov	eax, [esp+64]    /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy          /* if (nbytes >= len) */
+
+	sub	eax, ecx         /* len -= nbytes */
+	rep     movsb
+	mov	esi, edi
+	sub	esi, ebp         /* from = out - dist */
+	jmp	L_do_copy
+
+ALIGN 4
+L_do_copy:
+	mov	ecx, eax
+	rep     movsb
+
+	mov	esi, [esp+8]      /* move in back to %esi, toss from */
+	mov	ebp, [esp+32]     /* ebp = lcode */
+	jmp	L_while_test
+
+L_test_for_end_of_block:
+	test	al, 32
+	jz	L_invalid_literal_length_code
+	mov	dword ptr [esp+72], 1
+	jmp	L_break_loop_with_status
+
+L_invalid_literal_length_code:
+	mov	dword ptr [esp+72], 2
+	jmp	L_break_loop_with_status
+
+L_invalid_distance_code:
+	mov	dword ptr [esp+72], 3
+	jmp	L_break_loop_with_status
+
+L_invalid_distance_too_far:
+	mov	esi, [esp+4]
+	mov	dword ptr [esp+72], 4
+	jmp	L_break_loop_with_status
+
+L_break_loop:
+	mov	dword ptr [esp+72], 0
+
+L_break_loop_with_status:
+/* put in, out, bits, and hold back into ar and pop esp */
+	mov	[esp+8], esi     /* save in */
+	mov	[esp+16], edi    /* save out */
+	mov	[esp+44], ebx    /* save bits */
+	mov	[esp+40], edx    /* save hold */
+	mov	ebp, [esp+4]     /* restore esp, ebp */
+	mov	esp, [esp]
+    }
+#else
+#error "x86 architecture not defined"
+#endif
+
+    if (ar.status > 1) {
+        if (ar.status == 2)
+            strm->msg = "invalid literal/length code";
+        else if (ar.status == 3)
+            strm->msg = "invalid distance code";
+        else
+            strm->msg = "invalid distance too far back";
+        state->mode = BAD;
+    }
+    else if ( ar.status == 1 ) {
+        state->mode = TYPE;
+    }
+
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    ar.len = ar.bits >> 3;
+    ar.in -= ar.len;
+    ar.bits -= ar.len << 3;
+    ar.hold &= (1U << ar.bits) - 1;
+
+    /* update state and return */
+    strm->next_in = ar.in;
+    strm->next_out = ar.out;
+    strm->avail_in = (unsigned)(ar.in < ar.last ?
+                                PAD_AVAIL_IN + (ar.last - ar.in) :
+                                PAD_AVAIL_IN - (ar.in - ar.last));
+    strm->avail_out = (unsigned)(ar.out < ar.end ?
+                                 PAD_AVAIL_OUT + (ar.end - ar.out) :
+                                 PAD_AVAIL_OUT - (ar.out - ar.end));
+    state->hold = ar.hold;
+    state->bits = ar.bits;
+    return;
+}
+
diff --git a/xs/src/png/zlib/contrib/inflate86/inffast.S b/xs/src/png/zlib/contrib/inflate86/inffast.S
new file mode 100644
index 000000000..2245a2905
--- /dev/null
+++ b/xs/src/png/zlib/contrib/inflate86/inffast.S
@@ -0,0 +1,1368 @@
+/*
+ * inffast.S is a hand tuned assembler version of:
+ *
+ * inffast.c -- fast decoding
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Copyright (C) 2003 Chris Anderson <christop@charm.net>
+ * Please use the copyright conditions above.
+ *
+ * This version (Jan-23-2003) of inflate_fast was coded and tested under
+ * GNU/Linux on a pentium 3, using the gcc-3.2 compiler distribution.  On that
+ * machine, I found that gzip style archives decompressed about 20% faster than
+ * the gcc-3.2 -O3 -fomit-frame-pointer compiled version.  Your results will
+ * depend on how large of a buffer is used for z_stream.next_in & next_out
+ * (8K-32K worked best for my 256K cpu cache) and how much overhead there is in
+ * stream processing I/O and crc32/addler32.  In my case, this routine used
+ * 70% of the cpu time and crc32 used 20%.
+ *
+ * I am confident that this version will work in the general case, but I have
+ * not tested a wide variety of datasets or a wide variety of platforms.
+ *
+ * Jan-24-2003 -- Added -DUSE_MMX define for slightly faster inflating.
+ * It should be a runtime flag instead of compile time flag...
+ *
+ * Jan-26-2003 -- Added runtime check for MMX support with cpuid instruction.
+ * With -DUSE_MMX, only MMX code is compiled.  With -DNO_MMX, only non-MMX code
+ * is compiled.  Without either option, runtime detection is enabled.  Runtime
+ * detection should work on all modern cpus and the recomended algorithm (flip
+ * ID bit on eflags and then use the cpuid instruction) is used in many
+ * multimedia applications.  Tested under win2k with gcc-2.95 and gas-2.12
+ * distributed with cygwin3.  Compiling with gcc-2.95 -c inffast.S -o
+ * inffast.obj generates a COFF object which can then be linked with MSVC++
+ * compiled code.  Tested under FreeBSD 4.7 with gcc-2.95.
+ *
+ * Jan-28-2003 -- Tested Athlon XP... MMX mode is slower than no MMX (and
+ * slower than compiler generated code).  Adjusted cpuid check to use the MMX
+ * code only for Pentiums < P4 until I have more data on the P4.  Speed
+ * improvment is only about 15% on the Athlon when compared with code generated
+ * with MSVC++.  Not sure yet, but I think the P4 will also be slower using the
+ * MMX mode because many of it's x86 ALU instructions execute in .5 cycles and
+ * have less latency than MMX ops.  Added code to buffer the last 11 bytes of
+ * the input stream since the MMX code grabs bits in chunks of 32, which
+ * differs from the inffast.c algorithm.  I don't think there would have been
+ * read overruns where a page boundary was crossed (a segfault), but there
+ * could have been overruns when next_in ends on unaligned memory (unintialized
+ * memory read).
+ *
+ * Mar-13-2003 -- P4 MMX is slightly slower than P4 NO_MMX.  I created a C
+ * version of the non-MMX code so that it doesn't depend on zstrm and zstate
+ * structure offsets which are hard coded in this file.  This was last tested
+ * with zlib-1.2.0 which is currently in beta testing, newer versions of this
+ * and inffas86.c can be found at http://www.eetbeetee.com/zlib/ and
+ * http://www.charm.net/~christop/zlib/
+ */
+
+
+/*
+ * if you have underscore linking problems (_inflate_fast undefined), try
+ * using -DGAS_COFF
+ */
+#if ! defined( GAS_COFF ) && ! defined( GAS_ELF )
+
+#if defined( WIN32 ) || defined( __CYGWIN__ )
+#define GAS_COFF /* windows object format */
+#else
+#define GAS_ELF
+#endif
+
+#endif /* ! GAS_COFF && ! GAS_ELF */
+
+
+#if defined( GAS_COFF )
+
+/* coff externals have underscores */
+#define inflate_fast _inflate_fast
+#define inflate_fast_use_mmx _inflate_fast_use_mmx
+
+#endif /* GAS_COFF */
+
+
+.file "inffast.S"
+
+.globl inflate_fast
+
+.text
+.align 4,0
+.L_invalid_literal_length_code_msg:
+.string "invalid literal/length code"
+
+.align 4,0
+.L_invalid_distance_code_msg:
+.string "invalid distance code"
+
+.align 4,0
+.L_invalid_distance_too_far_msg:
+.string "invalid distance too far back"
+
+#if ! defined( NO_MMX )
+.align 4,0
+.L_mask: /* mask[N] = ( 1 << N ) - 1 */
+.long 0
+.long 1
+.long 3
+.long 7
+.long 15
+.long 31
+.long 63
+.long 127
+.long 255
+.long 511
+.long 1023
+.long 2047
+.long 4095
+.long 8191
+.long 16383
+.long 32767
+.long 65535
+.long 131071
+.long 262143
+.long 524287
+.long 1048575
+.long 2097151
+.long 4194303
+.long 8388607
+.long 16777215
+.long 33554431
+.long 67108863
+.long 134217727
+.long 268435455
+.long 536870911
+.long 1073741823
+.long 2147483647
+.long 4294967295
+#endif /* NO_MMX */
+
+.text
+
+/*
+ * struct z_stream offsets, in zlib.h
+ */
+#define next_in_strm   0   /* strm->next_in */
+#define avail_in_strm  4   /* strm->avail_in */
+#define next_out_strm  12  /* strm->next_out */
+#define avail_out_strm 16  /* strm->avail_out */
+#define msg_strm       24  /* strm->msg */
+#define state_strm     28  /* strm->state */
+
+/*
+ * struct inflate_state offsets, in inflate.h
+ */
+#define mode_state     0   /* state->mode */
+#define wsize_state    32  /* state->wsize */
+#define write_state    40  /* state->write */
+#define window_state   44  /* state->window */
+#define hold_state     48  /* state->hold */
+#define bits_state     52  /* state->bits */
+#define lencode_state  68  /* state->lencode */
+#define distcode_state 72  /* state->distcode */
+#define lenbits_state  76  /* state->lenbits */
+#define distbits_state 80  /* state->distbits */
+
+/*
+ * inflate_fast's activation record
+ */
+#define local_var_size 64 /* how much local space for vars */
+#define strm_sp        88 /* first arg: z_stream * (local_var_size + 24) */
+#define start_sp       92 /* second arg: unsigned int (local_var_size + 28) */
+
+/*
+ * offsets for local vars on stack
+ */
+#define out            60  /* unsigned char* */
+#define window         56  /* unsigned char* */
+#define wsize          52  /* unsigned int */
+#define write          48  /* unsigned int */
+#define in             44  /* unsigned char* */
+#define beg            40  /* unsigned char* */
+#define buf            28  /* char[ 12 ] */
+#define len            24  /* unsigned int */
+#define last           20  /* unsigned char* */
+#define end            16  /* unsigned char* */
+#define dcode          12  /* code* */
+#define lcode           8  /* code* */
+#define dmask           4  /* unsigned int */
+#define lmask           0  /* unsigned int */
+
+/*
+ * typedef enum inflate_mode consts, in inflate.h
+ */
+#define INFLATE_MODE_TYPE 11  /* state->mode flags enum-ed in inflate.h */
+#define INFLATE_MODE_BAD  26
+
+
+#if ! defined( USE_MMX ) && ! defined( NO_MMX )
+
+#define RUN_TIME_MMX
+
+#define CHECK_MMX    1
+#define DO_USE_MMX   2
+#define DONT_USE_MMX 3
+
+.globl inflate_fast_use_mmx
+
+.data
+
+.align 4,0
+inflate_fast_use_mmx: /* integer flag for run time control 1=check,2=mmx,3=no */
+.long CHECK_MMX
+
+#if defined( GAS_ELF )
+/* elf info */
+.type   inflate_fast_use_mmx,@object
+.size   inflate_fast_use_mmx,4
+#endif
+
+#endif /* RUN_TIME_MMX */
+
+#if defined( GAS_COFF )
+/* coff info: scl 2 = extern, type 32 = function */
+.def inflate_fast; .scl 2; .type 32; .endef
+#endif
+
+.text
+
+.align 32,0x90
+inflate_fast:
+        pushl   %edi
+        pushl   %esi
+        pushl   %ebp
+        pushl   %ebx
+        pushf   /* save eflags (strm_sp, state_sp assumes this is 32 bits) */
+        subl    $local_var_size, %esp
+        cld
+
+#define strm_r  %esi
+#define state_r %edi
+
+        movl    strm_sp(%esp), strm_r
+        movl    state_strm(strm_r), state_r
+
+        /* in = strm->next_in;
+         * out = strm->next_out;
+         * last = in + strm->avail_in - 11;
+         * beg = out - (start - strm->avail_out);
+         * end = out + (strm->avail_out - 257);
+         */
+        movl    avail_in_strm(strm_r), %edx
+        movl    next_in_strm(strm_r), %eax
+
+        addl    %eax, %edx      /* avail_in += next_in */
+        subl    $11, %edx       /* avail_in -= 11 */
+
+        movl    %eax, in(%esp)
+        movl    %edx, last(%esp)
+
+        movl    start_sp(%esp), %ebp
+        movl    avail_out_strm(strm_r), %ecx
+        movl    next_out_strm(strm_r), %ebx
+
+        subl    %ecx, %ebp      /* start -= avail_out */
+        negl    %ebp            /* start = -start */
+        addl    %ebx, %ebp      /* start += next_out */
+
+        subl    $257, %ecx      /* avail_out -= 257 */
+        addl    %ebx, %ecx      /* avail_out += out */
+
+        movl    %ebx, out(%esp)
+        movl    %ebp, beg(%esp)
+        movl    %ecx, end(%esp)
+
+        /* wsize = state->wsize;
+         * write = state->write;
+         * window = state->window;
+         * hold = state->hold;
+         * bits = state->bits;
+         * lcode = state->lencode;
+         * dcode = state->distcode;
+         * lmask = ( 1 << state->lenbits ) - 1;
+         * dmask = ( 1 << state->distbits ) - 1;
+         */
+
+        movl    lencode_state(state_r), %eax
+        movl    distcode_state(state_r), %ecx
+
+        movl    %eax, lcode(%esp)
+        movl    %ecx, dcode(%esp)
+
+        movl    $1, %eax
+        movl    lenbits_state(state_r), %ecx
+        shll    %cl, %eax
+        decl    %eax
+        movl    %eax, lmask(%esp)
+
+        movl    $1, %eax
+        movl    distbits_state(state_r), %ecx
+        shll    %cl, %eax
+        decl    %eax
+        movl    %eax, dmask(%esp)
+
+        movl    wsize_state(state_r), %eax
+        movl    write_state(state_r), %ecx
+        movl    window_state(state_r), %edx
+
+        movl    %eax, wsize(%esp)
+        movl    %ecx, write(%esp)
+        movl    %edx, window(%esp)
+
+        movl    hold_state(state_r), %ebp
+        movl    bits_state(state_r), %ebx
+
+#undef strm_r
+#undef state_r
+
+#define in_r       %esi
+#define from_r     %esi
+#define out_r      %edi
+
+        movl    in(%esp), in_r
+        movl    last(%esp), %ecx
+        cmpl    in_r, %ecx
+        ja      .L_align_long           /* if in < last */
+
+        addl    $11, %ecx               /* ecx = &in[ avail_in ] */
+        subl    in_r, %ecx              /* ecx = avail_in */
+        movl    $12, %eax
+        subl    %ecx, %eax              /* eax = 12 - avail_in */
+        leal    buf(%esp), %edi
+        rep     movsb                   /* memcpy( buf, in, avail_in ) */
+        movl    %eax, %ecx
+        xorl    %eax, %eax
+        rep     stosb         /* memset( &buf[ avail_in ], 0, 12 - avail_in ) */
+        leal    buf(%esp), in_r         /* in = buf */
+        movl    in_r, last(%esp)        /* last = in, do just one iteration */
+        jmp     .L_is_aligned
+
+        /* align in_r on long boundary */
+.L_align_long:
+        testl   $3, in_r
+        jz      .L_is_aligned
+        xorl    %eax, %eax
+        movb    (in_r), %al
+        incl    in_r
+        movl    %ebx, %ecx
+        addl    $8, %ebx
+        shll    %cl, %eax
+        orl     %eax, %ebp
+        jmp     .L_align_long
+
+.L_is_aligned:
+        movl    out(%esp), out_r
+
+#if defined( NO_MMX )
+        jmp     .L_do_loop
+#endif
+
+#if defined( USE_MMX )
+        jmp     .L_init_mmx
+#endif
+
+/*** Runtime MMX check ***/
+
+#if defined( RUN_TIME_MMX )
+.L_check_mmx:
+        cmpl    $DO_USE_MMX, inflate_fast_use_mmx
+        je      .L_init_mmx
+        ja      .L_do_loop /* > 2 */
+
+        pushl   %eax
+        pushl   %ebx
+        pushl   %ecx
+        pushl   %edx
+        pushf
+        movl    (%esp), %eax      /* copy eflags to eax */
+        xorl    $0x200000, (%esp) /* try toggling ID bit of eflags (bit 21)
+                                   * to see if cpu supports cpuid...
+                                   * ID bit method not supported by NexGen but
+                                   * bios may load a cpuid instruction and
+                                   * cpuid may be disabled on Cyrix 5-6x86 */
+        popf
+        pushf
+        popl    %edx              /* copy new eflags to edx */
+        xorl    %eax, %edx        /* test if ID bit is flipped */
+        jz      .L_dont_use_mmx   /* not flipped if zero */
+        xorl    %eax, %eax
+        cpuid
+        cmpl    $0x756e6547, %ebx /* check for GenuineIntel in ebx,ecx,edx */
+        jne     .L_dont_use_mmx
+        cmpl    $0x6c65746e, %ecx
+        jne     .L_dont_use_mmx
+        cmpl    $0x49656e69, %edx
+        jne     .L_dont_use_mmx
+        movl    $1, %eax
+        cpuid                     /* get cpu features */
+        shrl    $8, %eax
+        andl    $15, %eax
+        cmpl    $6, %eax          /* check for Pentium family, is 0xf for P4 */
+        jne     .L_dont_use_mmx
+        testl   $0x800000, %edx   /* test if MMX feature is set (bit 23) */
+        jnz     .L_use_mmx
+        jmp     .L_dont_use_mmx
+.L_use_mmx:
+        movl    $DO_USE_MMX, inflate_fast_use_mmx
+        jmp     .L_check_mmx_pop
+.L_dont_use_mmx:
+        movl    $DONT_USE_MMX, inflate_fast_use_mmx
+.L_check_mmx_pop:
+        popl    %edx
+        popl    %ecx
+        popl    %ebx
+        popl    %eax
+        jmp     .L_check_mmx
+#endif
+
+
+/*** Non-MMX code ***/
+
+#if defined ( NO_MMX ) || defined( RUN_TIME_MMX )
+
+#define hold_r     %ebp
+#define bits_r     %bl
+#define bitslong_r %ebx
+
+.align 32,0x90
+.L_while_test:
+        /* while (in < last && out < end)
+         */
+        cmpl    out_r, end(%esp)
+        jbe     .L_break_loop           /* if (out >= end) */
+
+        cmpl    in_r, last(%esp)
+        jbe     .L_break_loop
+
+.L_do_loop:
+        /* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out
+         *
+         * do {
+         *   if (bits < 15) {
+         *     hold |= *((unsigned short *)in)++ << bits;
+         *     bits += 16
+         *   }
+         *   this = lcode[hold & lmask]
+         */
+        cmpb    $15, bits_r
+        ja      .L_get_length_code      /* if (15 < bits) */
+
+        xorl    %eax, %eax
+        lodsw                           /* al = *(ushort *)in++ */
+        movb    bits_r, %cl             /* cl = bits, needs it for shifting */
+        addb    $16, bits_r             /* bits += 16 */
+        shll    %cl, %eax
+        orl     %eax, hold_r            /* hold |= *((ushort *)in)++ << bits */
+
+.L_get_length_code:
+        movl    lmask(%esp), %edx       /* edx = lmask */
+        movl    lcode(%esp), %ecx       /* ecx = lcode */
+        andl    hold_r, %edx            /* edx &= hold */
+        movl    (%ecx,%edx,4), %eax     /* eax = lcode[hold & lmask] */
+
+.L_dolen:
+        /* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out
+         *
+         * dolen:
+         *    bits -= this.bits;
+         *    hold >>= this.bits
+         */
+        movb    %ah, %cl                /* cl = this.bits */
+        subb    %ah, bits_r             /* bits -= this.bits */
+        shrl    %cl, hold_r             /* hold >>= this.bits */
+
+        /* check if op is a literal
+         * if (op == 0) {
+         *    PUP(out) = this.val;
+         *  }
+         */
+        testb   %al, %al
+        jnz     .L_test_for_length_base /* if (op != 0) 45.7% */
+
+        shrl    $16, %eax               /* output this.val char */
+        stosb
+        jmp     .L_while_test
+
+.L_test_for_length_base:
+        /* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out, %edx = len
+         *
+         * else if (op & 16) {
+         *   len = this.val
+         *   op &= 15
+         *   if (op) {
+         *     if (op > bits) {
+         *       hold |= *((unsigned short *)in)++ << bits;
+         *       bits += 16
+         *     }
+         *     len += hold & mask[op];
+         *     bits -= op;
+         *     hold >>= op;
+         *   }
+         */
+#define len_r %edx
+        movl    %eax, len_r             /* len = this */
+        shrl    $16, len_r              /* len = this.val */
+        movb    %al, %cl
+
+        testb   $16, %al
+        jz      .L_test_for_second_level_length /* if ((op & 16) == 0) 8% */
+        andb    $15, %cl                /* op &= 15 */
+        jz      .L_save_len             /* if (!op) */
+        cmpb    %cl, bits_r
+        jae     .L_add_bits_to_len      /* if (op <= bits) */
+
+        movb    %cl, %ch                /* stash op in ch, freeing cl */
+        xorl    %eax, %eax
+        lodsw                           /* al = *(ushort *)in++ */
+        movb    bits_r, %cl             /* cl = bits, needs it for shifting */
+        addb    $16, bits_r             /* bits += 16 */
+        shll    %cl, %eax
+        orl     %eax, hold_r            /* hold |= *((ushort *)in)++ << bits */
+        movb    %ch, %cl                /* move op back to ecx */
+
+.L_add_bits_to_len:
+        movl    $1, %eax
+        shll    %cl, %eax
+        decl    %eax
+        subb    %cl, bits_r
+        andl    hold_r, %eax            /* eax &= hold */
+        shrl    %cl, hold_r
+        addl    %eax, len_r             /* len += hold & mask[op] */
+
+.L_save_len:
+        movl    len_r, len(%esp)        /* save len */
+#undef  len_r
+
+.L_decode_distance:
+        /* regs: %esi = in, %ebp = hold, %bl = bits, %edi = out, %edx = dist
+         *
+         *   if (bits < 15) {
+         *     hold |= *((unsigned short *)in)++ << bits;
+         *     bits += 16
+         *   }
+         *   this = dcode[hold & dmask];
+         * dodist:
+         *   bits -= this.bits;
+         *   hold >>= this.bits;
+         *   op = this.op;
+         */
+
+        cmpb    $15, bits_r
+        ja      .L_get_distance_code    /* if (15 < bits) */
+
+        xorl    %eax, %eax
+        lodsw                           /* al = *(ushort *)in++ */
+        movb    bits_r, %cl             /* cl = bits, needs it for shifting */
+        addb    $16, bits_r             /* bits += 16 */
+        shll    %cl, %eax
+        orl     %eax, hold_r            /* hold |= *((ushort *)in)++ << bits */
+
+.L_get_distance_code:
+        movl    dmask(%esp), %edx       /* edx = dmask */
+        movl    dcode(%esp), %ecx       /* ecx = dcode */
+        andl    hold_r, %edx            /* edx &= hold */
+        movl    (%ecx,%edx,4), %eax     /* eax = dcode[hold & dmask] */
+
+#define dist_r %edx
+.L_dodist:
+        movl    %eax, dist_r            /* dist = this */
+        shrl    $16, dist_r             /* dist = this.val */
+        movb    %ah, %cl
+        subb    %ah, bits_r             /* bits -= this.bits */
+        shrl    %cl, hold_r             /* hold >>= this.bits */
+
+        /* if (op & 16) {
+         *   dist = this.val
+         *   op &= 15
+         *   if (op > bits) {
+         *     hold |= *((unsigned short *)in)++ << bits;
+         *     bits += 16
+         *   }
+         *   dist += hold & mask[op];
+         *   bits -= op;
+         *   hold >>= op;
+         */
+        movb    %al, %cl                /* cl = this.op */
+
+        testb   $16, %al                /* if ((op & 16) == 0) */
+        jz      .L_test_for_second_level_dist
+        andb    $15, %cl                /* op &= 15 */
+        jz      .L_check_dist_one
+        cmpb    %cl, bits_r
+        jae     .L_add_bits_to_dist     /* if (op <= bits) 97.6% */
+
+        movb    %cl, %ch                /* stash op in ch, freeing cl */
+        xorl    %eax, %eax
+        lodsw                           /* al = *(ushort *)in++ */
+        movb    bits_r, %cl             /* cl = bits, needs it for shifting */
+        addb    $16, bits_r             /* bits += 16 */
+        shll    %cl, %eax
+        orl     %eax, hold_r            /* hold |= *((ushort *)in)++ << bits */
+        movb    %ch, %cl                /* move op back to ecx */
+
+.L_add_bits_to_dist:
+        movl    $1, %eax
+        shll    %cl, %eax
+        decl    %eax                    /* (1 << op) - 1 */
+        subb    %cl, bits_r
+        andl    hold_r, %eax            /* eax &= hold */
+        shrl    %cl, hold_r
+        addl    %eax, dist_r            /* dist += hold & ((1 << op) - 1) */
+        jmp     .L_check_window
+
+.L_check_window:
+        /* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist
+         *       %ecx = nbytes
+         *
+         * nbytes = out - beg;
+         * if (dist <= nbytes) {
+         *   from = out - dist;
+         *   do {
+         *     PUP(out) = PUP(from);
+         *   } while (--len > 0) {
+         * }
+         */
+
+        movl    in_r, in(%esp)          /* save in so from can use it's reg */
+        movl    out_r, %eax
+        subl    beg(%esp), %eax         /* nbytes = out - beg */
+
+        cmpl    dist_r, %eax
+        jb      .L_clip_window          /* if (dist > nbytes) 4.2% */
+
+        movl    len(%esp), %ecx
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+
+        subl    $3, %ecx
+        movb    (from_r), %al
+        movb    %al, (out_r)
+        movb    1(from_r), %al
+        movb    2(from_r), %dl
+        addl    $3, from_r
+        movb    %al, 1(out_r)
+        movb    %dl, 2(out_r)
+        addl    $3, out_r
+        rep     movsb
+
+        movl    in(%esp), in_r          /* move in back to %esi, toss from */
+        jmp     .L_while_test
+
+.align 16,0x90
+.L_check_dist_one:
+        cmpl    $1, dist_r
+        jne     .L_check_window
+        cmpl    out_r, beg(%esp)
+        je      .L_check_window
+
+        decl    out_r
+        movl    len(%esp), %ecx
+        movb    (out_r), %al
+        subl    $3, %ecx
+
+        movb    %al, 1(out_r)
+        movb    %al, 2(out_r)
+        movb    %al, 3(out_r)
+        addl    $4, out_r
+        rep     stosb
+
+        jmp     .L_while_test
+
+.align 16,0x90
+.L_test_for_second_level_length:
+        /* else if ((op & 64) == 0) {
+         *   this = lcode[this.val + (hold & mask[op])];
+         * }
+         */
+        testb   $64, %al
+        jnz     .L_test_for_end_of_block  /* if ((op & 64) != 0) */
+
+        movl    $1, %eax
+        shll    %cl, %eax
+        decl    %eax
+        andl    hold_r, %eax            /* eax &= hold */
+        addl    %edx, %eax              /* eax += this.val */
+        movl    lcode(%esp), %edx       /* edx = lcode */
+        movl    (%edx,%eax,4), %eax     /* eax = lcode[val + (hold&mask[op])] */
+        jmp     .L_dolen
+
+.align 16,0x90
+.L_test_for_second_level_dist:
+        /* else if ((op & 64) == 0) {
+         *   this = dcode[this.val + (hold & mask[op])];
+         * }
+         */
+        testb   $64, %al
+        jnz     .L_invalid_distance_code  /* if ((op & 64) != 0) */
+
+        movl    $1, %eax
+        shll    %cl, %eax
+        decl    %eax
+        andl    hold_r, %eax            /* eax &= hold */
+        addl    %edx, %eax              /* eax += this.val */
+        movl    dcode(%esp), %edx       /* edx = dcode */
+        movl    (%edx,%eax,4), %eax     /* eax = dcode[val + (hold&mask[op])] */
+        jmp     .L_dodist
+
+.align 16,0x90
+.L_clip_window:
+        /* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist
+         *       %ecx = nbytes
+         *
+         * else {
+         *   if (dist > wsize) {
+         *     invalid distance
+         *   }
+         *   from = window;
+         *   nbytes = dist - nbytes;
+         *   if (write == 0) {
+         *     from += wsize - nbytes;
+         */
+#define nbytes_r %ecx
+        movl    %eax, nbytes_r
+        movl    wsize(%esp), %eax       /* prepare for dist compare */
+        negl    nbytes_r                /* nbytes = -nbytes */
+        movl    window(%esp), from_r    /* from = window */
+
+        cmpl    dist_r, %eax
+        jb      .L_invalid_distance_too_far /* if (dist > wsize) */
+
+        addl    dist_r, nbytes_r        /* nbytes = dist - nbytes */
+        cmpl    $0, write(%esp)
+        jne     .L_wrap_around_window   /* if (write != 0) */
+
+        subl    nbytes_r, %eax
+        addl    %eax, from_r            /* from += wsize - nbytes */
+
+        /* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist
+         *       %ecx = nbytes, %eax = len
+         *
+         *     if (nbytes < len) {
+         *       len -= nbytes;
+         *       do {
+         *         PUP(out) = PUP(from);
+         *       } while (--nbytes);
+         *       from = out - dist;
+         *     }
+         *   }
+         */
+#define len_r %eax
+        movl    len(%esp), len_r
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1             /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+        jmp     .L_do_copy1
+
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1             /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+        jmp     .L_do_copy1
+
+.L_wrap_around_window:
+        /* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist
+         *       %ecx = nbytes, %eax = write, %eax = len
+         *
+         *   else if (write < nbytes) {
+         *     from += wsize + write - nbytes;
+         *     nbytes -= write;
+         *     if (nbytes < len) {
+         *       len -= nbytes;
+         *       do {
+         *         PUP(out) = PUP(from);
+         *       } while (--nbytes);
+         *       from = window;
+         *       nbytes = write;
+         *       if (nbytes < len) {
+         *         len -= nbytes;
+         *         do {
+         *           PUP(out) = PUP(from);
+         *         } while(--nbytes);
+         *         from = out - dist;
+         *       }
+         *     }
+         *   }
+         */
+#define write_r %eax
+        movl    write(%esp), write_r
+        cmpl    write_r, nbytes_r
+        jbe     .L_contiguous_in_window /* if (write >= nbytes) */
+
+        addl    wsize(%esp), from_r
+        addl    write_r, from_r
+        subl    nbytes_r, from_r        /* from += wsize + write - nbytes */
+        subl    write_r, nbytes_r       /* nbytes -= write */
+#undef write_r
+
+        movl    len(%esp), len_r
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1             /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    window(%esp), from_r    /* from = window */
+        movl    write(%esp), nbytes_r   /* nbytes = write */
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1             /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+        jmp     .L_do_copy1
+
+.L_contiguous_in_window:
+        /* regs: %esi = from, %ebp = hold, %bl = bits, %edi = out, %edx = dist
+         *       %ecx = nbytes, %eax = write, %eax = len
+         *
+         *   else {
+         *     from += write - nbytes;
+         *     if (nbytes < len) {
+         *       len -= nbytes;
+         *       do {
+         *         PUP(out) = PUP(from);
+         *       } while (--nbytes);
+         *       from = out - dist;
+         *     }
+         *   }
+         */
+#define write_r %eax
+        addl    write_r, from_r
+        subl    nbytes_r, from_r        /* from += write - nbytes */
+#undef write_r
+
+        movl    len(%esp), len_r
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1             /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+
+.L_do_copy1:
+        /* regs: %esi = from, %esi = in, %ebp = hold, %bl = bits, %edi = out
+         *       %eax = len
+         *
+         *     while (len > 0) {
+         *       PUP(out) = PUP(from);
+         *       len--;
+         *     }
+         *   }
+         * } while (in < last && out < end);
+         */
+#undef nbytes_r
+#define in_r %esi
+        movl    len_r, %ecx
+        rep     movsb
+
+        movl    in(%esp), in_r          /* move in back to %esi, toss from */
+        jmp     .L_while_test
+
+#undef len_r
+#undef dist_r
+
+#endif /* NO_MMX || RUN_TIME_MMX */
+
+
+/*** MMX code ***/
+
+#if defined( USE_MMX ) || defined( RUN_TIME_MMX )
+
+.align 32,0x90
+.L_init_mmx:
+        emms
+
+#undef  bits_r
+#undef  bitslong_r
+#define bitslong_r %ebp
+#define hold_mm    %mm0
+        movd    %ebp, hold_mm
+        movl    %ebx, bitslong_r
+
+#define used_mm   %mm1
+#define dmask2_mm %mm2
+#define lmask2_mm %mm3
+#define lmask_mm  %mm4
+#define dmask_mm  %mm5
+#define tmp_mm    %mm6
+
+        movd    lmask(%esp), lmask_mm
+        movq    lmask_mm, lmask2_mm
+        movd    dmask(%esp), dmask_mm
+        movq    dmask_mm, dmask2_mm
+        pxor    used_mm, used_mm
+        movl    lcode(%esp), %ebx       /* ebx = lcode */
+        jmp     .L_do_loop_mmx
+
+.align 32,0x90
+.L_while_test_mmx:
+        /* while (in < last && out < end)
+         */
+        cmpl    out_r, end(%esp)
+        jbe     .L_break_loop           /* if (out >= end) */
+
+        cmpl    in_r, last(%esp)
+        jbe     .L_break_loop
+
+.L_do_loop_mmx:
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+
+        cmpl    $32, bitslong_r
+        ja      .L_get_length_code_mmx  /* if (32 < bits) */
+
+        movd    bitslong_r, tmp_mm
+        movd    (in_r), %mm7
+        addl    $4, in_r
+        psllq   tmp_mm, %mm7
+        addl    $32, bitslong_r
+        por     %mm7, hold_mm           /* hold_mm |= *((uint *)in)++ << bits */
+
+.L_get_length_code_mmx:
+        pand    hold_mm, lmask_mm
+        movd    lmask_mm, %eax
+        movq    lmask2_mm, lmask_mm
+        movl    (%ebx,%eax,4), %eax     /* eax = lcode[hold & lmask] */
+
+.L_dolen_mmx:
+        movzbl  %ah, %ecx               /* ecx = this.bits */
+        movd    %ecx, used_mm
+        subl    %ecx, bitslong_r        /* bits -= this.bits */
+
+        testb   %al, %al
+        jnz     .L_test_for_length_base_mmx /* if (op != 0) 45.7% */
+
+        shrl    $16, %eax               /* output this.val char */
+        stosb
+        jmp     .L_while_test_mmx
+
+.L_test_for_length_base_mmx:
+#define len_r  %edx
+        movl    %eax, len_r             /* len = this */
+        shrl    $16, len_r              /* len = this.val */
+
+        testb   $16, %al
+        jz      .L_test_for_second_level_length_mmx /* if ((op & 16) == 0) 8% */
+        andl    $15, %eax               /* op &= 15 */
+        jz      .L_decode_distance_mmx  /* if (!op) */
+
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+        movd    %eax, used_mm
+        movd    hold_mm, %ecx
+        subl    %eax, bitslong_r
+        andl    .L_mask(,%eax,4), %ecx
+        addl    %ecx, len_r             /* len += hold & mask[op] */
+
+.L_decode_distance_mmx:
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+
+        cmpl    $32, bitslong_r
+        ja      .L_get_dist_code_mmx    /* if (32 < bits) */
+
+        movd    bitslong_r, tmp_mm
+        movd    (in_r), %mm7
+        addl    $4, in_r
+        psllq   tmp_mm, %mm7
+        addl    $32, bitslong_r
+        por     %mm7, hold_mm           /* hold_mm |= *((uint *)in)++ << bits */
+
+.L_get_dist_code_mmx:
+        movl    dcode(%esp), %ebx       /* ebx = dcode */
+        pand    hold_mm, dmask_mm
+        movd    dmask_mm, %eax
+        movq    dmask2_mm, dmask_mm
+        movl    (%ebx,%eax,4), %eax     /* eax = dcode[hold & lmask] */
+
+.L_dodist_mmx:
+#define dist_r %ebx
+        movzbl  %ah, %ecx               /* ecx = this.bits */
+        movl    %eax, dist_r
+        shrl    $16, dist_r             /* dist  = this.val */
+        subl    %ecx, bitslong_r        /* bits -= this.bits */
+        movd    %ecx, used_mm
+
+        testb   $16, %al                /* if ((op & 16) == 0) */
+        jz      .L_test_for_second_level_dist_mmx
+        andl    $15, %eax               /* op &= 15 */
+        jz      .L_check_dist_one_mmx
+
+.L_add_bits_to_dist_mmx:
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+        movd    %eax, used_mm           /* save bit length of current op */
+        movd    hold_mm, %ecx           /* get the next bits on input stream */
+        subl    %eax, bitslong_r        /* bits -= op bits */
+        andl    .L_mask(,%eax,4), %ecx  /* ecx   = hold & mask[op] */
+        addl    %ecx, dist_r            /* dist += hold & mask[op] */
+
+.L_check_window_mmx:
+        movl    in_r, in(%esp)          /* save in so from can use it's reg */
+        movl    out_r, %eax
+        subl    beg(%esp), %eax         /* nbytes = out - beg */
+
+        cmpl    dist_r, %eax
+        jb      .L_clip_window_mmx      /* if (dist > nbytes) 4.2% */
+
+        movl    len_r, %ecx
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+
+        subl    $3, %ecx
+        movb    (from_r), %al
+        movb    %al, (out_r)
+        movb    1(from_r), %al
+        movb    2(from_r), %dl
+        addl    $3, from_r
+        movb    %al, 1(out_r)
+        movb    %dl, 2(out_r)
+        addl    $3, out_r
+        rep     movsb
+
+        movl    in(%esp), in_r          /* move in back to %esi, toss from */
+        movl    lcode(%esp), %ebx       /* move lcode back to %ebx, toss dist */
+        jmp     .L_while_test_mmx
+
+.align 16,0x90
+.L_check_dist_one_mmx:
+        cmpl    $1, dist_r
+        jne     .L_check_window_mmx
+        cmpl    out_r, beg(%esp)
+        je      .L_check_window_mmx
+
+        decl    out_r
+        movl    len_r, %ecx
+        movb    (out_r), %al
+        subl    $3, %ecx
+
+        movb    %al, 1(out_r)
+        movb    %al, 2(out_r)
+        movb    %al, 3(out_r)
+        addl    $4, out_r
+        rep     stosb
+
+        movl    lcode(%esp), %ebx       /* move lcode back to %ebx, toss dist */
+        jmp     .L_while_test_mmx
+
+.align 16,0x90
+.L_test_for_second_level_length_mmx:
+        testb   $64, %al
+        jnz     .L_test_for_end_of_block  /* if ((op & 64) != 0) */
+
+        andl    $15, %eax
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+        movd    hold_mm, %ecx
+        andl    .L_mask(,%eax,4), %ecx
+        addl    len_r, %ecx
+        movl    (%ebx,%ecx,4), %eax     /* eax = lcode[hold & lmask] */
+        jmp     .L_dolen_mmx
+
+.align 16,0x90
+.L_test_for_second_level_dist_mmx:
+        testb   $64, %al
+        jnz     .L_invalid_distance_code  /* if ((op & 64) != 0) */
+
+        andl    $15, %eax
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+        movd    hold_mm, %ecx
+        andl    .L_mask(,%eax,4), %ecx
+        movl    dcode(%esp), %eax       /* ecx = dcode */
+        addl    dist_r, %ecx
+        movl    (%eax,%ecx,4), %eax     /* eax = lcode[hold & lmask] */
+        jmp     .L_dodist_mmx
+
+.align 16,0x90
+.L_clip_window_mmx:
+#define nbytes_r %ecx
+        movl    %eax, nbytes_r
+        movl    wsize(%esp), %eax       /* prepare for dist compare */
+        negl    nbytes_r                /* nbytes = -nbytes */
+        movl    window(%esp), from_r    /* from = window */
+
+        cmpl    dist_r, %eax
+        jb      .L_invalid_distance_too_far /* if (dist > wsize) */
+
+        addl    dist_r, nbytes_r        /* nbytes = dist - nbytes */
+        cmpl    $0, write(%esp)
+        jne     .L_wrap_around_window_mmx /* if (write != 0) */
+
+        subl    nbytes_r, %eax
+        addl    %eax, from_r            /* from += wsize - nbytes */
+
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1_mmx         /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+        jmp     .L_do_copy1_mmx
+
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1_mmx         /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+        jmp     .L_do_copy1_mmx
+
+.L_wrap_around_window_mmx:
+#define write_r %eax
+        movl    write(%esp), write_r
+        cmpl    write_r, nbytes_r
+        jbe     .L_contiguous_in_window_mmx /* if (write >= nbytes) */
+
+        addl    wsize(%esp), from_r
+        addl    write_r, from_r
+        subl    nbytes_r, from_r        /* from += wsize + write - nbytes */
+        subl    write_r, nbytes_r       /* nbytes -= write */
+#undef write_r
+
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1_mmx         /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    window(%esp), from_r    /* from = window */
+        movl    write(%esp), nbytes_r   /* nbytes = write */
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1_mmx         /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+        jmp     .L_do_copy1_mmx
+
+.L_contiguous_in_window_mmx:
+#define write_r %eax
+        addl    write_r, from_r
+        subl    nbytes_r, from_r        /* from += write - nbytes */
+#undef write_r
+
+        cmpl    nbytes_r, len_r
+        jbe     .L_do_copy1_mmx         /* if (nbytes >= len) */
+
+        subl    nbytes_r, len_r         /* len -= nbytes */
+        rep     movsb
+        movl    out_r, from_r
+        subl    dist_r, from_r          /* from = out - dist */
+
+.L_do_copy1_mmx:
+#undef nbytes_r
+#define in_r %esi
+        movl    len_r, %ecx
+        rep     movsb
+
+        movl    in(%esp), in_r          /* move in back to %esi, toss from */
+        movl    lcode(%esp), %ebx       /* move lcode back to %ebx, toss dist */
+        jmp     .L_while_test_mmx
+
+#undef hold_r
+#undef bitslong_r
+
+#endif /* USE_MMX || RUN_TIME_MMX */
+
+
+/*** USE_MMX, NO_MMX, and RUNTIME_MMX from here on ***/
+
+.L_invalid_distance_code:
+        /* else {
+         *   strm->msg = "invalid distance code";
+         *   state->mode = BAD;
+         * }
+         */
+        movl    $.L_invalid_distance_code_msg, %ecx
+        movl    $INFLATE_MODE_BAD, %edx
+        jmp     .L_update_stream_state
+
+.L_test_for_end_of_block:
+        /* else if (op & 32) {
+         *   state->mode = TYPE;
+         *   break;
+         * }
+         */
+        testb   $32, %al
+        jz      .L_invalid_literal_length_code  /* if ((op & 32) == 0) */
+
+        movl    $0, %ecx
+        movl    $INFLATE_MODE_TYPE, %edx
+        jmp     .L_update_stream_state
+
+.L_invalid_literal_length_code:
+        /* else {
+         *   strm->msg = "invalid literal/length code";
+         *   state->mode = BAD;
+         * }
+         */
+        movl    $.L_invalid_literal_length_code_msg, %ecx
+        movl    $INFLATE_MODE_BAD, %edx
+        jmp     .L_update_stream_state
+
+.L_invalid_distance_too_far:
+        /* strm->msg = "invalid distance too far back";
+         * state->mode = BAD;
+         */
+        movl    in(%esp), in_r          /* from_r has in's reg, put in back */
+        movl    $.L_invalid_distance_too_far_msg, %ecx
+        movl    $INFLATE_MODE_BAD, %edx
+        jmp     .L_update_stream_state
+
+.L_update_stream_state:
+        /* set strm->msg = %ecx, strm->state->mode = %edx */
+        movl    strm_sp(%esp), %eax
+        testl   %ecx, %ecx              /* if (msg != NULL) */
+        jz      .L_skip_msg
+        movl    %ecx, msg_strm(%eax)    /* strm->msg = msg */
+.L_skip_msg:
+        movl    state_strm(%eax), %eax  /* state = strm->state */
+        movl    %edx, mode_state(%eax)  /* state->mode = edx (BAD | TYPE) */
+        jmp     .L_break_loop
+
+.align 32,0x90
+.L_break_loop:
+
+/*
+ * Regs:
+ *
+ * bits = %ebp when mmx, and in %ebx when non-mmx
+ * hold = %hold_mm when mmx, and in %ebp when non-mmx
+ * in   = %esi
+ * out  = %edi
+ */
+
+#if defined( USE_MMX ) || defined( RUN_TIME_MMX )
+
+#if defined( RUN_TIME_MMX )
+
+        cmpl    $DO_USE_MMX, inflate_fast_use_mmx
+        jne     .L_update_next_in
+
+#endif /* RUN_TIME_MMX */
+
+        movl    %ebp, %ebx
+
+.L_update_next_in:
+
+#endif
+
+#define strm_r  %eax
+#define state_r %edx
+
+        /* len = bits >> 3;
+         * in -= len;
+         * bits -= len << 3;
+         * hold &= (1U << bits) - 1;
+         * state->hold = hold;
+         * state->bits = bits;
+         * strm->next_in = in;
+         * strm->next_out = out;
+         */
+        movl    strm_sp(%esp), strm_r
+        movl    %ebx, %ecx
+        movl    state_strm(strm_r), state_r
+        shrl    $3, %ecx
+        subl    %ecx, in_r
+        shll    $3, %ecx
+        subl    %ecx, %ebx
+        movl    out_r, next_out_strm(strm_r)
+        movl    %ebx, bits_state(state_r)
+        movl    %ebx, %ecx
+
+        leal    buf(%esp), %ebx
+        cmpl    %ebx, last(%esp)
+        jne     .L_buf_not_used         /* if buf != last */
+
+        subl    %ebx, in_r              /* in -= buf */
+        movl    next_in_strm(strm_r), %ebx
+        movl    %ebx, last(%esp)        /* last = strm->next_in */
+        addl    %ebx, in_r              /* in += strm->next_in */
+        movl    avail_in_strm(strm_r), %ebx
+        subl    $11, %ebx
+        addl    %ebx, last(%esp)    /* last = &strm->next_in[ avail_in - 11 ] */
+
+.L_buf_not_used:
+        movl    in_r, next_in_strm(strm_r)
+
+        movl    $1, %ebx
+        shll    %cl, %ebx
+        decl    %ebx
+
+#if defined( USE_MMX ) || defined( RUN_TIME_MMX )
+
+#if defined( RUN_TIME_MMX )
+
+        cmpl    $DO_USE_MMX, inflate_fast_use_mmx
+        jne     .L_update_hold
+
+#endif /* RUN_TIME_MMX */
+
+        psrlq   used_mm, hold_mm        /* hold_mm >>= last bit length */
+        movd    hold_mm, %ebp
+
+        emms
+
+.L_update_hold:
+
+#endif /* USE_MMX || RUN_TIME_MMX */
+
+        andl    %ebx, %ebp
+        movl    %ebp, hold_state(state_r)
+
+#define last_r %ebx
+
+        /* strm->avail_in = in < last ? 11 + (last - in) : 11 - (in - last) */
+        movl    last(%esp), last_r
+        cmpl    in_r, last_r
+        jbe     .L_last_is_smaller     /* if (in >= last) */
+
+        subl    in_r, last_r           /* last -= in */
+        addl    $11, last_r            /* last += 11 */
+        movl    last_r, avail_in_strm(strm_r)
+        jmp     .L_fixup_out
+.L_last_is_smaller:
+        subl    last_r, in_r           /* in -= last */
+        negl    in_r                   /* in = -in */
+        addl    $11, in_r              /* in += 11 */
+        movl    in_r, avail_in_strm(strm_r)
+
+#undef last_r
+#define end_r %ebx
+
+.L_fixup_out:
+        /* strm->avail_out = out < end ? 257 + (end - out) : 257 - (out - end)*/
+        movl    end(%esp), end_r
+        cmpl    out_r, end_r
+        jbe     .L_end_is_smaller      /* if (out >= end) */
+
+        subl    out_r, end_r           /* end -= out */
+        addl    $257, end_r            /* end += 257 */
+        movl    end_r, avail_out_strm(strm_r)
+        jmp     .L_done
+.L_end_is_smaller:
+        subl    end_r, out_r           /* out -= end */
+        negl    out_r                  /* out = -out */
+        addl    $257, out_r            /* out += 257 */
+        movl    out_r, avail_out_strm(strm_r)
+
+#undef end_r
+#undef strm_r
+#undef state_r
+
+.L_done:
+        addl    $local_var_size, %esp
+        popf
+        popl    %ebx
+        popl    %ebp
+        popl    %esi
+        popl    %edi
+        ret
+
+#if defined( GAS_ELF )
+/* elf info */
+.type inflate_fast,@function
+.size inflate_fast,.-inflate_fast
+#endif
diff --git a/xs/src/png/zlib/contrib/iostream/test.cpp b/xs/src/png/zlib/contrib/iostream/test.cpp
new file mode 100644
index 000000000..7d265b3b5
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream/test.cpp
@@ -0,0 +1,24 @@
+
+#include "zfstream.h"
+
+int main() {
+
+  // Construct a stream object with this filebuffer.  Anything sent
+  // to this stream will go to standard out.
+  gzofstream os( 1, ios::out );
+
+  // This text is getting compressed and sent to stdout.
+  // To prove this, run 'test | zcat'.
+  os << "Hello, Mommy" << endl;
+
+  os << setcompressionlevel( Z_NO_COMPRESSION );
+  os << "hello, hello, hi, ho!" << endl;
+
+  setcompressionlevel( os, Z_DEFAULT_COMPRESSION )
+    << "I'm compressing again" << endl;
+
+  os.close();
+
+  return 0;
+
+}
diff --git a/xs/src/png/zlib/contrib/iostream/zfstream.cpp b/xs/src/png/zlib/contrib/iostream/zfstream.cpp
new file mode 100644
index 000000000..d0cd85faa
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream/zfstream.cpp
@@ -0,0 +1,329 @@
+
+#include "zfstream.h"
+
+gzfilebuf::gzfilebuf() :
+  file(NULL),
+  mode(0),
+  own_file_descriptor(0)
+{ }
+
+gzfilebuf::~gzfilebuf() {
+
+  sync();
+  if ( own_file_descriptor )
+    close();
+
+}
+
+gzfilebuf *gzfilebuf::open( const char *name,
+                            int io_mode ) {
+
+  if ( is_open() )
+    return NULL;
+
+  char char_mode[10];
+  char *p = char_mode;
+
+  if ( io_mode & ios::in ) {
+    mode = ios::in;
+    *p++ = 'r';
+  } else if ( io_mode & ios::app ) {
+    mode = ios::app;
+    *p++ = 'a';
+  } else {
+    mode = ios::out;
+    *p++ = 'w';
+  }
+
+  if ( io_mode & ios::binary ) {
+    mode |= ios::binary;
+    *p++ = 'b';
+  }
+
+  // Hard code the compression level
+  if ( io_mode & (ios::out|ios::app )) {
+    *p++ = '9';
+  }
+
+  // Put the end-of-string indicator
+  *p = '\0';
+
+  if ( (file = gzopen(name, char_mode)) == NULL )
+    return NULL;
+
+  own_file_descriptor = 1;
+
+  return this;
+
+}
+
+gzfilebuf *gzfilebuf::attach( int file_descriptor,
+                              int io_mode ) {
+
+  if ( is_open() )
+    return NULL;
+
+  char char_mode[10];
+  char *p = char_mode;
+
+  if ( io_mode & ios::in ) {
+    mode = ios::in;
+    *p++ = 'r';
+  } else if ( io_mode & ios::app ) {
+    mode = ios::app;
+    *p++ = 'a';
+  } else {
+    mode = ios::out;
+    *p++ = 'w';
+  }
+
+  if ( io_mode & ios::binary ) {
+    mode |= ios::binary;
+    *p++ = 'b';
+  }
+
+  // Hard code the compression level
+  if ( io_mode & (ios::out|ios::app )) {
+    *p++ = '9';
+  }
+
+  // Put the end-of-string indicator
+  *p = '\0';
+
+  if ( (file = gzdopen(file_descriptor, char_mode)) == NULL )
+    return NULL;
+
+  own_file_descriptor = 0;
+
+  return this;
+
+}
+
+gzfilebuf *gzfilebuf::close() {
+
+  if ( is_open() ) {
+
+    sync();
+    gzclose( file );
+    file = NULL;
+
+  }
+
+  return this;
+
+}
+
+int gzfilebuf::setcompressionlevel( int comp_level ) {
+
+  return gzsetparams(file, comp_level, -2);
+
+}
+
+int gzfilebuf::setcompressionstrategy( int comp_strategy ) {
+
+  return gzsetparams(file, -2, comp_strategy);
+
+}
+
+
+streampos gzfilebuf::seekoff( streamoff off, ios::seek_dir dir, int which ) {
+
+  return streampos(EOF);
+
+}
+
+int gzfilebuf::underflow() {
+
+  // If the file hasn't been opened for reading, error.
+  if ( !is_open() || !(mode & ios::in) )
+    return EOF;
+
+  // if a buffer doesn't exists, allocate one.
+  if ( !base() ) {
+
+    if ( (allocate()) == EOF )
+      return EOF;
+    setp(0,0);
+
+  } else {
+
+    if ( in_avail() )
+      return (unsigned char) *gptr();
+
+    if ( out_waiting() ) {
+      if ( flushbuf() == EOF )
+        return EOF;
+    }
+
+  }
+
+  // Attempt to fill the buffer.
+
+  int result = fillbuf();
+  if ( result == EOF ) {
+    // disable get area
+    setg(0,0,0);
+    return EOF;
+  }
+
+  return (unsigned char) *gptr();
+
+}
+
+int gzfilebuf::overflow( int c ) {
+
+  if ( !is_open() || !(mode & ios::out) )
+    return EOF;
+
+  if ( !base() ) {
+    if ( allocate() == EOF )
+      return EOF;
+    setg(0,0,0);
+  } else {
+    if (in_avail()) {
+        return EOF;
+    }
+    if (out_waiting()) {
+      if (flushbuf() == EOF)
+        return EOF;
+    }
+  }
+
+  int bl = blen();
+  setp( base(), base() + bl);
+
+  if ( c != EOF ) {
+
+    *pptr() = c;
+    pbump(1);
+
+  }
+
+  return 0;
+
+}
+
+int gzfilebuf::sync() {
+
+  if ( !is_open() )
+    return EOF;
+
+  if ( out_waiting() )
+    return flushbuf();
+
+  return 0;
+
+}
+
+int gzfilebuf::flushbuf() {
+
+  int n;
+  char *q;
+
+  q = pbase();
+  n = pptr() - q;
+
+  if ( gzwrite( file, q, n) < n )
+    return EOF;
+
+  setp(0,0);
+
+  return 0;
+
+}
+
+int gzfilebuf::fillbuf() {
+
+  int required;
+  char *p;
+
+  p = base();
+
+  required = blen();
+
+  int t = gzread( file, p, required );
+
+  if ( t <= 0) return EOF;
+
+  setg( base(), base(), base()+t);
+
+  return t;
+
+}
+
+gzfilestream_common::gzfilestream_common() :
+  ios( gzfilestream_common::rdbuf() )
+{ }
+
+gzfilestream_common::~gzfilestream_common()
+{ }
+
+void gzfilestream_common::attach( int fd, int io_mode ) {
+
+  if ( !buffer.attach( fd, io_mode) )
+    clear( ios::failbit | ios::badbit );
+  else
+    clear();
+
+}
+
+void gzfilestream_common::open( const char *name, int io_mode ) {
+
+  if ( !buffer.open( name, io_mode ) )
+    clear( ios::failbit | ios::badbit );
+  else
+    clear();
+
+}
+
+void gzfilestream_common::close() {
+
+  if ( !buffer.close() )
+    clear( ios::failbit | ios::badbit );
+
+}
+
+gzfilebuf *gzfilestream_common::rdbuf()
+{
+  return &buffer;
+}
+
+gzifstream::gzifstream() :
+  ios( gzfilestream_common::rdbuf() )
+{
+  clear( ios::badbit );
+}
+
+gzifstream::gzifstream( const char *name, int io_mode ) :
+  ios( gzfilestream_common::rdbuf() )
+{
+  gzfilestream_common::open( name, io_mode );
+}
+
+gzifstream::gzifstream( int fd, int io_mode ) :
+  ios( gzfilestream_common::rdbuf() )
+{
+  gzfilestream_common::attach( fd, io_mode );
+}
+
+gzifstream::~gzifstream() { }
+
+gzofstream::gzofstream() :
+  ios( gzfilestream_common::rdbuf() )
+{
+  clear( ios::badbit );
+}
+
+gzofstream::gzofstream( const char *name, int io_mode ) :
+  ios( gzfilestream_common::rdbuf() )
+{
+  gzfilestream_common::open( name, io_mode );
+}
+
+gzofstream::gzofstream( int fd, int io_mode ) :
+  ios( gzfilestream_common::rdbuf() )
+{
+  gzfilestream_common::attach( fd, io_mode );
+}
+
+gzofstream::~gzofstream() { }
diff --git a/xs/src/png/zlib/contrib/iostream/zfstream.h b/xs/src/png/zlib/contrib/iostream/zfstream.h
new file mode 100644
index 000000000..ed79098a3
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream/zfstream.h
@@ -0,0 +1,128 @@
+
+#ifndef zfstream_h
+#define zfstream_h
+
+#include <fstream.h>
+#include "zlib.h"
+
+class gzfilebuf : public streambuf {
+
+public:
+
+  gzfilebuf( );
+  virtual ~gzfilebuf();
+
+  gzfilebuf *open( const char *name, int io_mode );
+  gzfilebuf *attach( int file_descriptor, int io_mode );
+  gzfilebuf *close();
+
+  int setcompressionlevel( int comp_level );
+  int setcompressionstrategy( int comp_strategy );
+
+  inline int is_open() const { return (file !=NULL); }
+
+  virtual streampos seekoff( streamoff, ios::seek_dir, int );
+
+  virtual int sync();
+
+protected:
+
+  virtual int underflow();
+  virtual int overflow( int = EOF );
+
+private:
+
+  gzFile file;
+  short mode;
+  short own_file_descriptor;
+
+  int flushbuf();
+  int fillbuf();
+
+};
+
+class gzfilestream_common : virtual public ios {
+
+  friend class gzifstream;
+  friend class gzofstream;
+  friend gzofstream &setcompressionlevel( gzofstream &, int );
+  friend gzofstream &setcompressionstrategy( gzofstream &, int );
+
+public:
+  virtual ~gzfilestream_common();
+
+  void attach( int fd, int io_mode );
+  void open( const char *name, int io_mode );
+  void close();
+
+protected:
+  gzfilestream_common();
+
+private:
+  gzfilebuf *rdbuf();
+
+  gzfilebuf buffer;
+
+};
+
+class gzifstream : public gzfilestream_common, public istream {
+
+public:
+
+  gzifstream();
+  gzifstream( const char *name, int io_mode = ios::in );
+  gzifstream( int fd, int io_mode = ios::in );
+
+  virtual ~gzifstream();
+
+};
+
+class gzofstream : public gzfilestream_common, public ostream {
+
+public:
+
+  gzofstream();
+  gzofstream( const char *name, int io_mode = ios::out );
+  gzofstream( int fd, int io_mode = ios::out );
+
+  virtual ~gzofstream();
+
+};
+
+template<class T> class gzomanip {
+  friend gzofstream &operator<<(gzofstream &, const gzomanip<T> &);
+public:
+  gzomanip(gzofstream &(*f)(gzofstream &, T), T v) : func(f), val(v) { }
+private:
+  gzofstream &(*func)(gzofstream &, T);
+  T val;
+};
+
+template<class T> gzofstream &operator<<(gzofstream &s, const gzomanip<T> &m)
+{
+  return (*m.func)(s, m.val);
+}
+
+inline gzofstream &setcompressionlevel( gzofstream &s, int l )
+{
+  (s.rdbuf())->setcompressionlevel(l);
+  return s;
+}
+
+inline gzofstream &setcompressionstrategy( gzofstream &s, int l )
+{
+  (s.rdbuf())->setcompressionstrategy(l);
+  return s;
+}
+
+inline gzomanip<int> setcompressionlevel(int l)
+{
+  return gzomanip<int>(&setcompressionlevel,l);
+}
+
+inline gzomanip<int> setcompressionstrategy(int l)
+{
+  return gzomanip<int>(&setcompressionstrategy,l);
+}
+
+#endif
diff --git a/xs/src/png/zlib/contrib/iostream2/zstream.h b/xs/src/png/zlib/contrib/iostream2/zstream.h
new file mode 100644
index 000000000..43d2332b7
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream2/zstream.h
@@ -0,0 +1,307 @@
+/*
+ *
+ * Copyright (c) 1997
+ * Christian Michelsen Research AS
+ * Advanced Computing
+ * Fantoftvegen 38, 5036 BERGEN, Norway
+ * http://www.cmr.no
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation.  Christian Michelsen Research AS makes no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ */
+
+#ifndef ZSTREAM__H
+#define ZSTREAM__H
+
+/*
+ * zstream.h - C++ interface to the 'zlib' general purpose compression library
+ * $Id: zstream.h 1.1 1997-06-25 12:00:56+02 tyge Exp tyge $
+ */
+
+#include <strstream.h>
+#include <string.h>
+#include <stdio.h>
+#include "zlib.h"
+
+#if defined(_WIN32)
+#   include <fcntl.h>
+#   include <io.h>
+#   define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+#   define SET_BINARY_MODE(file)
+#endif
+
+class zstringlen {
+public:
+    zstringlen(class izstream&);
+    zstringlen(class ozstream&, const char*);
+    size_t value() const { return val.word; }
+private:
+    struct Val { unsigned char byte; size_t word; } val;
+};
+
+//  ----------------------------- izstream -----------------------------
+
+class izstream
+{
+    public:
+        izstream() : m_fp(0) {}
+        izstream(FILE* fp) : m_fp(0) { open(fp); }
+        izstream(const char* name) : m_fp(0) { open(name); }
+        ~izstream() { close(); }
+
+        /* Opens a gzip (.gz) file for reading.
+         * open() can be used to read a file which is not in gzip format;
+         * in this case read() will directly read from the file without
+         * decompression. errno can be checked to distinguish two error
+         * cases (if errno is zero, the zlib error is Z_MEM_ERROR).
+         */
+        void open(const char* name) {
+            if (m_fp) close();
+            m_fp = ::gzopen(name, "rb");
+        }
+
+        void open(FILE* fp) {
+            SET_BINARY_MODE(fp);
+            if (m_fp) close();
+            m_fp = ::gzdopen(fileno(fp), "rb");
+        }
+
+        /* Flushes all pending input if necessary, closes the compressed file
+         * and deallocates all the (de)compression state. The return value is
+         * the zlib error number (see function error() below).
+         */
+        int close() {
+            int r = ::gzclose(m_fp);
+            m_fp = 0; return r;
+        }
+
+        /* Binary read the given number of bytes from the compressed file.
+         */
+        int read(void* buf, size_t len) {
+            return ::gzread(m_fp, buf, len);
+        }
+
+        /* Returns the error message for the last error which occurred on the
+         * given compressed file. errnum is set to zlib error number. If an
+         * error occurred in the file system and not in the compression library,
+         * errnum is set to Z_ERRNO and the application may consult errno
+         * to get the exact error code.
+         */
+        const char* error(int* errnum) {
+            return ::gzerror(m_fp, errnum);
+        }
+
+        gzFile fp() { return m_fp; }
+
+    private:
+        gzFile m_fp;
+};
+
+/*
+ * Binary read the given (array of) object(s) from the compressed file.
+ * If the input file was not in gzip format, read() copies the objects number
+ * of bytes into the buffer.
+ * returns the number of uncompressed bytes actually read
+ * (0 for end of file, -1 for error).
+ */
+template <class T, class Items>
+inline int read(izstream& zs, T* x, Items items) {
+    return ::gzread(zs.fp(), x, items*sizeof(T));
+}
+
+/*
+ * Binary input with the '>' operator.
+ */
+template <class T>
+inline izstream& operator>(izstream& zs, T& x) {
+    ::gzread(zs.fp(), &x, sizeof(T));
+    return zs;
+}
+
+
+inline zstringlen::zstringlen(izstream& zs) {
+    zs > val.byte;
+    if (val.byte == 255) zs > val.word;
+    else val.word = val.byte;
+}
+
+/*
+ * Read length of string + the string with the '>' operator.
+ */
+inline izstream& operator>(izstream& zs, char* x) {
+    zstringlen len(zs);
+    ::gzread(zs.fp(), x, len.value());
+    x[len.value()] = '\0';
+    return zs;
+}
+
+inline char* read_string(izstream& zs) {
+    zstringlen len(zs);
+    char* x = new char[len.value()+1];
+    ::gzread(zs.fp(), x, len.value());
+    x[len.value()] = '\0';
+    return x;
+}
+
+// ----------------------------- ozstream -----------------------------
+
+class ozstream
+{
+    public:
+        ozstream() : m_fp(0), m_os(0) {
+        }
+        ozstream(FILE* fp, int level = Z_DEFAULT_COMPRESSION)
+            : m_fp(0), m_os(0) {
+            open(fp, level);
+        }
+        ozstream(const char* name, int level = Z_DEFAULT_COMPRESSION)
+            : m_fp(0), m_os(0) {
+            open(name, level);
+        }
+        ~ozstream() {
+            close();
+        }
+
+        /* Opens a gzip (.gz) file for writing.
+         * The compression level parameter should be in 0..9
+         * errno can be checked to distinguish two error cases
+         * (if errno is zero, the zlib error is Z_MEM_ERROR).
+         */
+        void open(const char* name, int level = Z_DEFAULT_COMPRESSION) {
+            char mode[4] = "wb\0";
+            if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level;
+            if (m_fp) close();
+            m_fp = ::gzopen(name, mode);
+        }
+
+        /* open from a FILE pointer.
+         */
+        void open(FILE* fp, int level = Z_DEFAULT_COMPRESSION) {
+            SET_BINARY_MODE(fp);
+            char mode[4] = "wb\0";
+            if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level;
+            if (m_fp) close();
+            m_fp = ::gzdopen(fileno(fp), mode);
+        }
+
+        /* Flushes all pending output if necessary, closes the compressed file
+         * and deallocates all the (de)compression state. The return value is
+         * the zlib error number (see function error() below).
+         */
+        int close() {
+            if (m_os) {
+                ::gzwrite(m_fp, m_os->str(), m_os->pcount());
+                delete[] m_os->str(); delete m_os; m_os = 0;
+            }
+            int r = ::gzclose(m_fp); m_fp = 0; return r;
+        }
+
+        /* Binary write the given number of bytes into the compressed file.
+         */
+        int write(const void* buf, size_t len) {
+            return ::gzwrite(m_fp, (voidp) buf, len);
+        }
+
+        /* Flushes all pending output into the compressed file. The parameter
+         * _flush is as in the deflate() function. The return value is the zlib
+         * error number (see function gzerror below). flush() returns Z_OK if
+         * the flush_ parameter is Z_FINISH and all output could be flushed.
+         * flush() should be called only when strictly necessary because it can
+         * degrade compression.
+         */
+        int flush(int _flush) {
+            os_flush();
+            return ::gzflush(m_fp, _flush);
+        }
+
+        /* Returns the error message for the last error which occurred on the
+         * given compressed file. errnum is set to zlib error number. If an
+         * error occurred in the file system and not in the compression library,
+         * errnum is set to Z_ERRNO and the application may consult errno
+         * to get the exact error code.
+         */
+        const char* error(int* errnum) {
+            return ::gzerror(m_fp, errnum);
+        }
+
+        gzFile fp() { return m_fp; }
+
+        ostream& os() {
+            if (m_os == 0) m_os = new ostrstream;
+            return *m_os;
+        }
+
+        void os_flush() {
+            if (m_os && m_os->pcount()>0) {
+                ostrstream* oss = new ostrstream;
+                oss->fill(m_os->fill());
+                oss->flags(m_os->flags());
+                oss->precision(m_os->precision());
+                oss->width(m_os->width());
+                ::gzwrite(m_fp, m_os->str(), m_os->pcount());
+                delete[] m_os->str(); delete m_os; m_os = oss;
+            }
+        }
+
+    private:
+        gzFile m_fp;
+        ostrstream* m_os;
+};
+
+/*
+ * Binary write the given (array of) object(s) into the compressed file.
+ * returns the number of uncompressed bytes actually written
+ * (0 in case of error).
+ */
+template <class T, class Items>
+inline int write(ozstream& zs, const T* x, Items items) {
+    return ::gzwrite(zs.fp(), (voidp) x, items*sizeof(T));
+}
+
+/*
+ * Binary output with the '<' operator.
+ */
+template <class T>
+inline ozstream& operator<(ozstream& zs, const T& x) {
+    ::gzwrite(zs.fp(), (voidp) &x, sizeof(T));
+    return zs;
+}
+
+inline zstringlen::zstringlen(ozstream& zs, const char* x) {
+    val.byte = 255;  val.word = ::strlen(x);
+    if (val.word < 255) zs < (val.byte = val.word);
+    else zs < val;
+}
+
+/*
+ * Write length of string + the string with the '<' operator.
+ */
+inline ozstream& operator<(ozstream& zs, const char* x) {
+    zstringlen len(zs, x);
+    ::gzwrite(zs.fp(), (voidp) x, len.value());
+    return zs;
+}
+
+#ifdef _MSC_VER
+inline ozstream& operator<(ozstream& zs, char* const& x) {
+    return zs < (const char*) x;
+}
+#endif
+
+/*
+ * Ascii write with the << operator;
+ */
+template <class T>
+inline ostream& operator<<(ozstream& zs, const T& x) {
+    zs.os_flush();
+    return zs.os() << x;
+}
+
+#endif
diff --git a/xs/src/png/zlib/contrib/iostream2/zstream_test.cpp b/xs/src/png/zlib/contrib/iostream2/zstream_test.cpp
new file mode 100644
index 000000000..6273f62d6
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream2/zstream_test.cpp
@@ -0,0 +1,25 @@
+#include "zstream.h"
+#include <math.h>
+#include <stdlib.h>
+#include <iomanip.h>
+
+void main() {
+    char h[256] = "Hello";
+    char* g = "Goodbye";
+    ozstream out("temp.gz");
+    out < "This works well" < h < g;
+    out.close();
+
+    izstream in("temp.gz"); // read it back
+    char *x = read_string(in), *y = new char[256], z[256];
+    in > y > z;
+    in.close();
+    cout << x << endl << y << endl << z << endl;
+
+    out.open("temp.gz"); // try ascii output; zcat temp.gz to see the results
+    out << setw(50) << setfill('#') << setprecision(20) << x << endl << y << endl << z << endl;
+    out << z << endl << y << endl << x << endl;
+    out << 1.1234567890123456789 << endl;
+
+    delete[] x; delete[] y;
+}
diff --git a/xs/src/png/zlib/contrib/iostream3/README b/xs/src/png/zlib/contrib/iostream3/README
new file mode 100644
index 000000000..f7b319ab9
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream3/README
@@ -0,0 +1,35 @@
+These classes provide a C++ stream interface to the zlib library. It allows you
+to do things like:
+
+  gzofstream outf("blah.gz");
+  outf << "These go into the gzip file " << 123 << endl;
+
+It does this by deriving a specialized stream buffer for gzipped files, which is
+the way Stroustrup would have done it. :->
+
+The gzifstream and gzofstream classes were originally written by Kevin Ruland
+and made available in the zlib contrib/iostream directory. The older version still
+compiles under gcc 2.xx, but not under gcc 3.xx, which sparked the development of
+this version.
+
+The new classes are as standard-compliant as possible, closely following the
+approach of the standard library's fstream classes. It compiles under gcc versions
+3.2 and 3.3, but not under gcc 2.xx. This is mainly due to changes in the standard
+library naming scheme. The new version of gzifstream/gzofstream/gzfilebuf differs
+from the previous one in the following respects:
+- added showmanyc
+- added setbuf, with support for unbuffered output via setbuf(0,0)
+- a few bug fixes of stream behavior
+- gzipped output file opened with default compression level instead of maximum level
+- setcompressionlevel()/strategy() members replaced by single setcompression()
+
+The code is provided "as is", with the permission to use, copy, modify, distribute
+and sell it for any purpose without fee.
+
+Ludwig Schwardt
+<schwardt@sun.ac.za>
+
+DSP Lab
+Electrical & Electronic Engineering Department
+University of Stellenbosch
+South Africa
diff --git a/xs/src/png/zlib/contrib/iostream3/TODO b/xs/src/png/zlib/contrib/iostream3/TODO
new file mode 100644
index 000000000..7032f97be
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream3/TODO
@@ -0,0 +1,17 @@
+Possible upgrades to gzfilebuf:
+
+- The ability to do putback (e.g. putbackfail)
+
+- The ability to seek (zlib supports this, but could be slow/tricky)
+
+- Simultaneous read/write access (does it make sense?)
+
+- Support for ios_base::ate open mode
+
+- Locale support?
+
+- Check public interface to see which calls give problems
+  (due to dependence on library internals)
+
+- Override operator<<(ostream&, gzfilebuf*) to allow direct copying
+  of stream buffer to stream ( i.e. os << is.rdbuf(); )
diff --git a/xs/src/png/zlib/contrib/iostream3/test.cc b/xs/src/png/zlib/contrib/iostream3/test.cc
new file mode 100644
index 000000000..94235334f
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream3/test.cc
@@ -0,0 +1,50 @@
+/*
+ * Test program for gzifstream and gzofstream
+ *
+ * by Ludwig Schwardt <schwardt@sun.ac.za>
+ * original version by Kevin Ruland <kevin@rodin.wustl.edu>
+ */
+
+#include "zfstream.h"
+#include <iostream>      // for cout
+
+int main() {
+
+  gzofstream outf;
+  gzifstream inf;
+  char buf[80];
+
+  outf.open("test1.txt.gz");
+  outf << "The quick brown fox sidestepped the lazy canine\n"
+       << 1.3 << "\nPlan " << 9 << std::endl;
+  outf.close();
+  std::cout << "Wrote the following message to 'test1.txt.gz' (check with zcat or zless):\n"
+            << "The quick brown fox sidestepped the lazy canine\n"
+            << 1.3 << "\nPlan " << 9 << std::endl;
+
+  std::cout << "\nReading 'test1.txt.gz' (buffered) produces:\n";
+  inf.open("test1.txt.gz");
+  while (inf.getline(buf,80,'\n')) {
+    std::cout << buf << "\t(" << inf.rdbuf()->in_avail() << " chars left in buffer)\n";
+  }
+  inf.close();
+
+  outf.rdbuf()->pubsetbuf(0,0);
+  outf.open("test2.txt.gz");
+  outf << setcompression(Z_NO_COMPRESSION)
+       << "The quick brown fox sidestepped the lazy canine\n"
+       << 1.3 << "\nPlan " << 9 << std::endl;
+  outf.close();
+  std::cout << "\nWrote the same message to 'test2.txt.gz' in uncompressed form";
+
+  std::cout << "\nReading 'test2.txt.gz' (unbuffered) produces:\n";
+  inf.rdbuf()->pubsetbuf(0,0);
+  inf.open("test2.txt.gz");
+  while (inf.getline(buf,80,'\n')) {
+    std::cout << buf << "\t(" << inf.rdbuf()->in_avail() << " chars left in buffer)\n";
+  }
+  inf.close();
+
+  return 0;
+
+}
diff --git a/xs/src/png/zlib/contrib/iostream3/zfstream.cc b/xs/src/png/zlib/contrib/iostream3/zfstream.cc
new file mode 100644
index 000000000..94eb93344
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream3/zfstream.cc
@@ -0,0 +1,479 @@
+/*
+ * A C++ I/O streams interface to the zlib gz* functions
+ *
+ * by Ludwig Schwardt <schwardt@sun.ac.za>
+ * original version by Kevin Ruland <kevin@rodin.wustl.edu>
+ *
+ * This version is standard-compliant and compatible with gcc 3.x.
+ */
+
+#include "zfstream.h"
+#include <cstring>          // for strcpy, strcat, strlen (mode strings)
+#include <cstdio>           // for BUFSIZ
+
+// Internal buffer sizes (default and "unbuffered" versions)
+#define BIGBUFSIZE BUFSIZ
+#define SMALLBUFSIZE 1
+
+/*****************************************************************************/
+
+// Default constructor
+gzfilebuf::gzfilebuf()
+: file(NULL), io_mode(std::ios_base::openmode(0)), own_fd(false),
+  buffer(NULL), buffer_size(BIGBUFSIZE), own_buffer(true)
+{
+  // No buffers to start with
+  this->disable_buffer();
+}
+
+// Destructor
+gzfilebuf::~gzfilebuf()
+{
+  // Sync output buffer and close only if responsible for file
+  // (i.e. attached streams should be left open at this stage)
+  this->sync();
+  if (own_fd)
+    this->close();
+  // Make sure internal buffer is deallocated
+  this->disable_buffer();
+}
+
+// Set compression level and strategy
+int
+gzfilebuf::setcompression(int comp_level,
+                          int comp_strategy)
+{
+  return gzsetparams(file, comp_level, comp_strategy);
+}
+
+// Open gzipped file
+gzfilebuf*
+gzfilebuf::open(const char *name,
+                std::ios_base::openmode mode)
+{
+  // Fail if file already open
+  if (this->is_open())
+    return NULL;
+  // Don't support simultaneous read/write access (yet)
+  if ((mode & std::ios_base::in) && (mode & std::ios_base::out))
+    return NULL;
+
+  // Build mode string for gzopen and check it [27.8.1.3.2]
+  char char_mode[6] = "\0\0\0\0\0";
+  if (!this->open_mode(mode, char_mode))
+    return NULL;
+
+  // Attempt to open file
+  if ((file = gzopen(name, char_mode)) == NULL)
+    return NULL;
+
+  // On success, allocate internal buffer and set flags
+  this->enable_buffer();
+  io_mode = mode;
+  own_fd = true;
+  return this;
+}
+
+// Attach to gzipped file
+gzfilebuf*
+gzfilebuf::attach(int fd,
+                  std::ios_base::openmode mode)
+{
+  // Fail if file already open
+  if (this->is_open())
+    return NULL;
+  // Don't support simultaneous read/write access (yet)
+  if ((mode & std::ios_base::in) && (mode & std::ios_base::out))
+    return NULL;
+
+  // Build mode string for gzdopen and check it [27.8.1.3.2]
+  char char_mode[6] = "\0\0\0\0\0";
+  if (!this->open_mode(mode, char_mode))
+    return NULL;
+
+  // Attempt to attach to file
+  if ((file = gzdopen(fd, char_mode)) == NULL)
+    return NULL;
+
+  // On success, allocate internal buffer and set flags
+  this->enable_buffer();
+  io_mode = mode;
+  own_fd = false;
+  return this;
+}
+
+// Close gzipped file
+gzfilebuf*
+gzfilebuf::close()
+{
+  // Fail immediately if no file is open
+  if (!this->is_open())
+    return NULL;
+  // Assume success
+  gzfilebuf* retval = this;
+  // Attempt to sync and close gzipped file
+  if (this->sync() == -1)
+    retval = NULL;
+  if (gzclose(file) < 0)
+    retval = NULL;
+  // File is now gone anyway (postcondition [27.8.1.3.8])
+  file = NULL;
+  own_fd = false;
+  // Destroy internal buffer if it exists
+  this->disable_buffer();
+  return retval;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+// Convert int open mode to mode string
+bool
+gzfilebuf::open_mode(std::ios_base::openmode mode,
+                     char* c_mode) const
+{
+  bool testb = mode & std::ios_base::binary;
+  bool testi = mode & std::ios_base::in;
+  bool testo = mode & std::ios_base::out;
+  bool testt = mode & std::ios_base::trunc;
+  bool testa = mode & std::ios_base::app;
+
+  // Check for valid flag combinations - see [27.8.1.3.2] (Table 92)
+  // Original zfstream hardcoded the compression level to maximum here...
+  // Double the time for less than 1% size improvement seems
+  // excessive though - keeping it at the default level
+  // To change back, just append "9" to the next three mode strings
+  if (!testi && testo && !testt && !testa)
+    strcpy(c_mode, "w");
+  if (!testi && testo && !testt && testa)
+    strcpy(c_mode, "a");
+  if (!testi && testo && testt && !testa)
+    strcpy(c_mode, "w");
+  if (testi && !testo && !testt && !testa)
+    strcpy(c_mode, "r");
+  // No read/write mode yet
+//  if (testi && testo && !testt && !testa)
+//    strcpy(c_mode, "r+");
+//  if (testi && testo && testt && !testa)
+//    strcpy(c_mode, "w+");
+
+  // Mode string should be empty for invalid combination of flags
+  if (strlen(c_mode) == 0)
+    return false;
+  if (testb)
+    strcat(c_mode, "b");
+  return true;
+}
+
+// Determine number of characters in internal get buffer
+std::streamsize
+gzfilebuf::showmanyc()
+{
+  // Calls to underflow will fail if file not opened for reading
+  if (!this->is_open() || !(io_mode & std::ios_base::in))
+    return -1;
+  // Make sure get area is in use
+  if (this->gptr() && (this->gptr() < this->egptr()))
+    return std::streamsize(this->egptr() - this->gptr());
+  else
+    return 0;
+}
+
+// Fill get area from gzipped file
+gzfilebuf::int_type
+gzfilebuf::underflow()
+{
+  // If something is left in the get area by chance, return it
+  // (this shouldn't normally happen, as underflow is only supposed
+  // to be called when gptr >= egptr, but it serves as error check)
+  if (this->gptr() && (this->gptr() < this->egptr()))
+    return traits_type::to_int_type(*(this->gptr()));
+
+  // If the file hasn't been opened for reading, produce error
+  if (!this->is_open() || !(io_mode & std::ios_base::in))
+    return traits_type::eof();
+
+  // Attempt to fill internal buffer from gzipped file
+  // (buffer must be guaranteed to exist...)
+  int bytes_read = gzread(file, buffer, buffer_size);
+  // Indicates error or EOF
+  if (bytes_read <= 0)
+  {
+    // Reset get area
+    this->setg(buffer, buffer, buffer);
+    return traits_type::eof();
+  }
+  // Make all bytes read from file available as get area
+  this->setg(buffer, buffer, buffer + bytes_read);
+
+  // Return next character in get area
+  return traits_type::to_int_type(*(this->gptr()));
+}
+
+// Write put area to gzipped file
+gzfilebuf::int_type
+gzfilebuf::overflow(int_type c)
+{
+  // Determine whether put area is in use
+  if (this->pbase())
+  {
+    // Double-check pointer range
+    if (this->pptr() > this->epptr() || this->pptr() < this->pbase())
+      return traits_type::eof();
+    // Add extra character to buffer if not EOF
+    if (!traits_type::eq_int_type(c, traits_type::eof()))
+    {
+      *(this->pptr()) = traits_type::to_char_type(c);
+      this->pbump(1);
+    }
+    // Number of characters to write to file
+    int bytes_to_write = this->pptr() - this->pbase();
+    // Overflow doesn't fail if nothing is to be written
+    if (bytes_to_write > 0)
+    {
+      // If the file hasn't been opened for writing, produce error
+      if (!this->is_open() || !(io_mode & std::ios_base::out))
+        return traits_type::eof();
+      // If gzipped file won't accept all bytes written to it, fail
+      if (gzwrite(file, this->pbase(), bytes_to_write) != bytes_to_write)
+        return traits_type::eof();
+      // Reset next pointer to point to pbase on success
+      this->pbump(-bytes_to_write);
+    }
+  }
+  // Write extra character to file if not EOF
+  else if (!traits_type::eq_int_type(c, traits_type::eof()))
+  {
+    // If the file hasn't been opened for writing, produce error
+    if (!this->is_open() || !(io_mode & std::ios_base::out))
+      return traits_type::eof();
+    // Impromptu char buffer (allows "unbuffered" output)
+    char_type last_char = traits_type::to_char_type(c);
+    // If gzipped file won't accept this character, fail
+    if (gzwrite(file, &last_char, 1) != 1)
+      return traits_type::eof();
+  }
+
+  // If you got here, you have succeeded (even if c was EOF)
+  // The return value should therefore be non-EOF
+  if (traits_type::eq_int_type(c, traits_type::eof()))
+    return traits_type::not_eof(c);
+  else
+    return c;
+}
+
+// Assign new buffer
+std::streambuf*
+gzfilebuf::setbuf(char_type* p,
+                  std::streamsize n)
+{
+  // First make sure stuff is sync'ed, for safety
+  if (this->sync() == -1)
+    return NULL;
+  // If buffering is turned off on purpose via setbuf(0,0), still allocate one...
+  // "Unbuffered" only really refers to put [27.8.1.4.10], while get needs at
+  // least a buffer of size 1 (very inefficient though, therefore make it bigger?)
+  // This follows from [27.5.2.4.3]/12 (gptr needs to point at something, it seems)
+  if (!p || !n)
+  {
+    // Replace existing buffer (if any) with small internal buffer
+    this->disable_buffer();
+    buffer = NULL;
+    buffer_size = 0;
+    own_buffer = true;
+    this->enable_buffer();
+  }
+  else
+  {
+    // Replace existing buffer (if any) with external buffer
+    this->disable_buffer();
+    buffer = p;
+    buffer_size = n;
+    own_buffer = false;
+    this->enable_buffer();
+  }
+  return this;
+}
+
+// Write put area to gzipped file (i.e. ensures that put area is empty)
+int
+gzfilebuf::sync()
+{
+  return traits_type::eq_int_type(this->overflow(), traits_type::eof()) ? -1 : 0;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+// Allocate internal buffer
+void
+gzfilebuf::enable_buffer()
+{
+  // If internal buffer required, allocate one
+  if (own_buffer && !buffer)
+  {
+    // Check for buffered vs. "unbuffered"
+    if (buffer_size > 0)
+    {
+      // Allocate internal buffer
+      buffer = new char_type[buffer_size];
+      // Get area starts empty and will be expanded by underflow as need arises
+      this->setg(buffer, buffer, buffer);
+      // Setup entire internal buffer as put area.
+      // The one-past-end pointer actually points to the last element of the buffer,
+      // so that overflow(c) can safely add the extra character c to the sequence.
+      // These pointers remain in place for the duration of the buffer
+      this->setp(buffer, buffer + buffer_size - 1);
+    }
+    else
+    {
+      // Even in "unbuffered" case, (small?) get buffer is still required
+      buffer_size = SMALLBUFSIZE;
+      buffer = new char_type[buffer_size];
+      this->setg(buffer, buffer, buffer);
+      // "Unbuffered" means no put buffer
+      this->setp(0, 0);
+    }
+  }
+  else
+  {
+    // If buffer already allocated, reset buffer pointers just to make sure no
+    // stale chars are lying around
+    this->setg(buffer, buffer, buffer);
+    this->setp(buffer, buffer + buffer_size - 1);
+  }
+}
+
+// Destroy internal buffer
+void
+gzfilebuf::disable_buffer()
+{
+  // If internal buffer exists, deallocate it
+  if (own_buffer && buffer)
+  {
+    // Preserve unbuffered status by zeroing size
+    if (!this->pbase())
+      buffer_size = 0;
+    delete[] buffer;
+    buffer = NULL;
+    this->setg(0, 0, 0);
+    this->setp(0, 0);
+  }
+  else
+  {
+    // Reset buffer pointers to initial state if external buffer exists
+    this->setg(buffer, buffer, buffer);
+    if (buffer)
+      this->setp(buffer, buffer + buffer_size - 1);
+    else
+      this->setp(0, 0);
+  }
+}
+
+/*****************************************************************************/
+
+// Default constructor initializes stream buffer
+gzifstream::gzifstream()
+: std::istream(NULL), sb()
+{ this->init(&sb); }
+
+// Initialize stream buffer and open file
+gzifstream::gzifstream(const char* name,
+                       std::ios_base::openmode mode)
+: std::istream(NULL), sb()
+{
+  this->init(&sb);
+  this->open(name, mode);
+}
+
+// Initialize stream buffer and attach to file
+gzifstream::gzifstream(int fd,
+                       std::ios_base::openmode mode)
+: std::istream(NULL), sb()
+{
+  this->init(&sb);
+  this->attach(fd, mode);
+}
+
+// Open file and go into fail() state if unsuccessful
+void
+gzifstream::open(const char* name,
+                 std::ios_base::openmode mode)
+{
+  if (!sb.open(name, mode | std::ios_base::in))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Attach to file and go into fail() state if unsuccessful
+void
+gzifstream::attach(int fd,
+                   std::ios_base::openmode mode)
+{
+  if (!sb.attach(fd, mode | std::ios_base::in))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Close file
+void
+gzifstream::close()
+{
+  if (!sb.close())
+    this->setstate(std::ios_base::failbit);
+}
+
+/*****************************************************************************/
+
+// Default constructor initializes stream buffer
+gzofstream::gzofstream()
+: std::ostream(NULL), sb()
+{ this->init(&sb); }
+
+// Initialize stream buffer and open file
+gzofstream::gzofstream(const char* name,
+                       std::ios_base::openmode mode)
+: std::ostream(NULL), sb()
+{
+  this->init(&sb);
+  this->open(name, mode);
+}
+
+// Initialize stream buffer and attach to file
+gzofstream::gzofstream(int fd,
+                       std::ios_base::openmode mode)
+: std::ostream(NULL), sb()
+{
+  this->init(&sb);
+  this->attach(fd, mode);
+}
+
+// Open file and go into fail() state if unsuccessful
+void
+gzofstream::open(const char* name,
+                 std::ios_base::openmode mode)
+{
+  if (!sb.open(name, mode | std::ios_base::out))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Attach to file and go into fail() state if unsuccessful
+void
+gzofstream::attach(int fd,
+                   std::ios_base::openmode mode)
+{
+  if (!sb.attach(fd, mode | std::ios_base::out))
+    this->setstate(std::ios_base::failbit);
+  else
+    this->clear();
+}
+
+// Close file
+void
+gzofstream::close()
+{
+  if (!sb.close())
+    this->setstate(std::ios_base::failbit);
+}
diff --git a/xs/src/png/zlib/contrib/iostream3/zfstream.h b/xs/src/png/zlib/contrib/iostream3/zfstream.h
new file mode 100644
index 000000000..8574479ae
--- /dev/null
+++ b/xs/src/png/zlib/contrib/iostream3/zfstream.h
@@ -0,0 +1,466 @@
+/*
+ * A C++ I/O streams interface to the zlib gz* functions
+ *
+ * by Ludwig Schwardt <schwardt@sun.ac.za>
+ * original version by Kevin Ruland <kevin@rodin.wustl.edu>
+ *
+ * This version is standard-compliant and compatible with gcc 3.x.
+ */
+
+#ifndef ZFSTREAM_H
+#define ZFSTREAM_H
+
+#include <istream>  // not iostream, since we don't need cin/cout
+#include <ostream>
+#include "zlib.h"
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file stream buffer class.
+ *
+ *  This class implements basic_filebuf for gzipped files. It doesn't yet support
+ *  seeking (allowed by zlib but slow/limited), putback and read/write access
+ *  (tricky). Otherwise, it attempts to be a drop-in replacement for the standard
+ *  file streambuf.
+*/
+class gzfilebuf : public std::streambuf
+{
+public:
+  //  Default constructor.
+  gzfilebuf();
+
+  //  Destructor.
+  virtual
+  ~gzfilebuf();
+
+  /**
+   *  @brief  Set compression level and strategy on the fly.
+   *  @param  comp_level  Compression level (see zlib.h for allowed values)
+   *  @param  comp_strategy  Compression strategy (see zlib.h for allowed values)
+   *  @return  Z_OK on success, Z_STREAM_ERROR otherwise.
+   *
+   *  Unfortunately, these parameters cannot be modified separately, as the
+   *  previous zfstream version assumed. Since the strategy is seldom changed,
+   *  it can default and setcompression(level) then becomes like the old
+   *  setcompressionlevel(level).
+  */
+  int
+  setcompression(int comp_level,
+                 int comp_strategy = Z_DEFAULT_STRATEGY);
+
+  /**
+   *  @brief  Check if file is open.
+   *  @return  True if file is open.
+  */
+  bool
+  is_open() const { return (file != NULL); }
+
+  /**
+   *  @brief  Open gzipped file.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags.
+   *  @return  @c this on success, NULL on failure.
+  */
+  gzfilebuf*
+  open(const char* name,
+       std::ios_base::openmode mode);
+
+  /**
+   *  @brief  Attach to already open gzipped file.
+   *  @param  fd  File descriptor.
+   *  @param  mode  Open mode flags.
+   *  @return  @c this on success, NULL on failure.
+  */
+  gzfilebuf*
+  attach(int fd,
+         std::ios_base::openmode mode);
+
+  /**
+   *  @brief  Close gzipped file.
+   *  @return  @c this on success, NULL on failure.
+  */
+  gzfilebuf*
+  close();
+
+protected:
+  /**
+   *  @brief  Convert ios open mode int to mode string used by zlib.
+   *  @return  True if valid mode flag combination.
+  */
+  bool
+  open_mode(std::ios_base::openmode mode,
+            char* c_mode) const;
+
+  /**
+   *  @brief  Number of characters available in stream buffer.
+   *  @return  Number of characters.
+   *
+   *  This indicates number of characters in get area of stream buffer.
+   *  These characters can be read without accessing the gzipped file.
+  */
+  virtual std::streamsize
+  showmanyc();
+
+  /**
+   *  @brief  Fill get area from gzipped file.
+   *  @return  First character in get area on success, EOF on error.
+   *
+   *  This actually reads characters from gzipped file to stream
+   *  buffer. Always buffered.
+  */
+  virtual int_type
+  underflow();
+
+  /**
+   *  @brief  Write put area to gzipped file.
+   *  @param  c  Extra character to add to buffer contents.
+   *  @return  Non-EOF on success, EOF on error.
+   *
+   *  This actually writes characters in stream buffer to
+   *  gzipped file. With unbuffered output this is done one
+   *  character at a time.
+  */
+  virtual int_type
+  overflow(int_type c = traits_type::eof());
+
+  /**
+   *  @brief  Installs external stream buffer.
+   *  @param  p  Pointer to char buffer.
+   *  @param  n  Size of external buffer.
+   *  @return  @c this on success, NULL on failure.
+   *
+   *  Call setbuf(0,0) to enable unbuffered output.
+  */
+  virtual std::streambuf*
+  setbuf(char_type* p,
+         std::streamsize n);
+
+  /**
+   *  @brief  Flush stream buffer to file.
+   *  @return  0 on success, -1 on error.
+   *
+   *  This calls underflow(EOF) to do the job.
+  */
+  virtual int
+  sync();
+
+//
+// Some future enhancements
+//
+//  virtual int_type uflow();
+//  virtual int_type pbackfail(int_type c = traits_type::eof());
+//  virtual pos_type
+//  seekoff(off_type off,
+//          std::ios_base::seekdir way,
+//          std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out);
+//  virtual pos_type
+//  seekpos(pos_type sp,
+//          std::ios_base::openmode mode = std::ios_base::in|std::ios_base::out);
+
+private:
+  /**
+   *  @brief  Allocate internal buffer.
+   *
+   *  This function is safe to call multiple times. It will ensure
+   *  that a proper internal buffer exists if it is required. If the
+   *  buffer already exists or is external, the buffer pointers will be
+   *  reset to their original state.
+  */
+  void
+  enable_buffer();
+
+  /**
+   *  @brief  Destroy internal buffer.
+   *
+   *  This function is safe to call multiple times. It will ensure
+   *  that the internal buffer is deallocated if it exists. In any
+   *  case, it will also reset the buffer pointers.
+  */
+  void
+  disable_buffer();
+
+  /**
+   *  Underlying file pointer.
+  */
+  gzFile file;
+
+  /**
+   *  Mode in which file was opened.
+  */
+  std::ios_base::openmode io_mode;
+
+  /**
+   *  @brief  True if this object owns file descriptor.
+   *
+   *  This makes the class responsible for closing the file
+   *  upon destruction.
+  */
+  bool own_fd;
+
+  /**
+   *  @brief  Stream buffer.
+   *
+   *  For simplicity this remains allocated on the free store for the
+   *  entire life span of the gzfilebuf object, unless replaced by setbuf.
+  */
+  char_type* buffer;
+
+  /**
+   *  @brief  Stream buffer size.
+   *
+   *  Defaults to system default buffer size (typically 8192 bytes).
+   *  Modified by setbuf.
+  */
+  std::streamsize buffer_size;
+
+  /**
+   *  @brief  True if this object owns stream buffer.
+   *
+   *  This makes the class responsible for deleting the buffer
+   *  upon destruction.
+  */
+  bool own_buffer;
+};
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file input stream class.
+ *
+ *  This class implements ifstream for gzipped files. Seeking and putback
+ *  is not supported yet.
+*/
+class gzifstream : public std::istream
+{
+public:
+  //  Default constructor
+  gzifstream();
+
+  /**
+   *  @brief  Construct stream on gzipped file to be opened.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+  */
+  explicit
+  gzifstream(const char* name,
+             std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  @brief  Construct stream on already open gzipped file.
+   *  @param  fd    File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+  */
+  explicit
+  gzifstream(int fd,
+             std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  Obtain underlying stream buffer.
+  */
+  gzfilebuf*
+  rdbuf() const
+  { return const_cast<gzfilebuf*>(&sb); }
+
+  /**
+   *  @brief  Check if file is open.
+   *  @return  True if file is open.
+  */
+  bool
+  is_open() { return sb.is_open(); }
+
+  /**
+   *  @brief  Open gzipped file.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+   *
+   *  Stream will be in state good() if file opens successfully;
+   *  otherwise in state fail(). This differs from the behavior of
+   *  ifstream, which never sets the state to good() and therefore
+   *  won't allow you to reuse the stream for a second file unless
+   *  you manually clear() the state. The choice is a matter of
+   *  convenience.
+  */
+  void
+  open(const char* name,
+       std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  @brief  Attach to already open gzipped file.
+   *  @param  fd  File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::in).
+   *
+   *  Stream will be in state good() if attach succeeded; otherwise
+   *  in state fail().
+  */
+  void
+  attach(int fd,
+         std::ios_base::openmode mode = std::ios_base::in);
+
+  /**
+   *  @brief  Close gzipped file.
+   *
+   *  Stream will be in state fail() if close failed.
+  */
+  void
+  close();
+
+private:
+  /**
+   *  Underlying stream buffer.
+  */
+  gzfilebuf sb;
+};
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file output stream class.
+ *
+ *  This class implements ofstream for gzipped files. Seeking and putback
+ *  is not supported yet.
+*/
+class gzofstream : public std::ostream
+{
+public:
+  //  Default constructor
+  gzofstream();
+
+  /**
+   *  @brief  Construct stream on gzipped file to be opened.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+  */
+  explicit
+  gzofstream(const char* name,
+             std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  @brief  Construct stream on already open gzipped file.
+   *  @param  fd    File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+  */
+  explicit
+  gzofstream(int fd,
+             std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  Obtain underlying stream buffer.
+  */
+  gzfilebuf*
+  rdbuf() const
+  { return const_cast<gzfilebuf*>(&sb); }
+
+  /**
+   *  @brief  Check if file is open.
+   *  @return  True if file is open.
+  */
+  bool
+  is_open() { return sb.is_open(); }
+
+  /**
+   *  @brief  Open gzipped file.
+   *  @param  name  File name.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+   *
+   *  Stream will be in state good() if file opens successfully;
+   *  otherwise in state fail(). This differs from the behavior of
+   *  ofstream, which never sets the state to good() and therefore
+   *  won't allow you to reuse the stream for a second file unless
+   *  you manually clear() the state. The choice is a matter of
+   *  convenience.
+  */
+  void
+  open(const char* name,
+       std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  @brief  Attach to already open gzipped file.
+   *  @param  fd  File descriptor.
+   *  @param  mode  Open mode flags (forced to contain ios::out).
+   *
+   *  Stream will be in state good() if attach succeeded; otherwise
+   *  in state fail().
+  */
+  void
+  attach(int fd,
+         std::ios_base::openmode mode = std::ios_base::out);
+
+  /**
+   *  @brief  Close gzipped file.
+   *
+   *  Stream will be in state fail() if close failed.
+  */
+  void
+  close();
+
+private:
+  /**
+   *  Underlying stream buffer.
+  */
+  gzfilebuf sb;
+};
+
+/*****************************************************************************/
+
+/**
+ *  @brief  Gzipped file output stream manipulator class.
+ *
+ *  This class defines a two-argument manipulator for gzofstream. It is used
+ *  as base for the setcompression(int,int) manipulator.
+*/
+template<typename T1, typename T2>
+  class gzomanip2
+  {
+  public:
+    // Allows insertor to peek at internals
+    template <typename Ta, typename Tb>
+      friend gzofstream&
+      operator<<(gzofstream&,
+                 const gzomanip2<Ta,Tb>&);
+
+    // Constructor
+    gzomanip2(gzofstream& (*f)(gzofstream&, T1, T2),
+              T1 v1,
+              T2 v2);
+  private:
+    // Underlying manipulator function
+    gzofstream&
+    (*func)(gzofstream&, T1, T2);
+
+    // Arguments for manipulator function
+    T1 val1;
+    T2 val2;
+  };
+
+/*****************************************************************************/
+
+// Manipulator function thunks through to stream buffer
+inline gzofstream&
+setcompression(gzofstream &gzs, int l, int s = Z_DEFAULT_STRATEGY)
+{
+  (gzs.rdbuf())->setcompression(l, s);
+  return gzs;
+}
+
+// Manipulator constructor stores arguments
+template<typename T1, typename T2>
+  inline
+  gzomanip2<T1,T2>::gzomanip2(gzofstream &(*f)(gzofstream &, T1, T2),
+                              T1 v1,
+                              T2 v2)
+  : func(f), val1(v1), val2(v2)
+  { }
+
+// Insertor applies underlying manipulator function to stream
+template<typename T1, typename T2>
+  inline gzofstream&
+  operator<<(gzofstream& s, const gzomanip2<T1,T2>& m)
+  { return (*m.func)(s, m.val1, m.val2); }
+
+// Insert this onto stream to simplify setting of compression level
+inline gzomanip2<int,int>
+setcompression(int l, int s = Z_DEFAULT_STRATEGY)
+{ return gzomanip2<int,int>(&setcompression, l, s); }
+
+#endif // ZFSTREAM_H
diff --git a/xs/src/png/zlib/contrib/masmx64/bld_ml64.bat b/xs/src/png/zlib/contrib/masmx64/bld_ml64.bat
new file mode 100644
index 000000000..f74bcef5b
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx64/bld_ml64.bat
@@ -0,0 +1,2 @@
+ml64.exe /Flinffasx64 /c /Zi inffasx64.asm
+ml64.exe /Flgvmat64   /c /Zi gvmat64.asm
diff --git a/xs/src/png/zlib/contrib/masmx64/gvmat64.asm b/xs/src/png/zlib/contrib/masmx64/gvmat64.asm
new file mode 100644
index 000000000..c1817f1be
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx64/gvmat64.asm
@@ -0,0 +1,553 @@
+;uInt longest_match_x64(
+;    deflate_state *s,
+;    IPos cur_match);                             /* current match */
+
+; gvmat64.asm -- Asm portion of the optimized longest_match for 32 bits x86_64
+;  (AMD64 on Athlon 64, Opteron, Phenom
+;     and Intel EM64T on Pentium 4 with EM64T, Pentium D, Core 2 Duo, Core I5/I7)
+; Copyright (C) 1995-2010 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
+;
+; File written by Gilles Vollant, by converting to assembly the longest_match
+;  from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
+;
+;  and by taking inspiration on asm686 with masm, optimised assembly code
+;        from Brian Raiter, written 1998
+;
+;  This software is provided 'as-is', without any express or implied
+;  warranty.  In no event will the authors be held liable for any damages
+;  arising from the use of this software.
+;
+;  Permission is granted to anyone to use this software for any purpose,
+;  including commercial applications, and to alter it and redistribute it
+;  freely, subject to the following restrictions:
+;
+;  1. The origin of this software must not be misrepresented; you must not
+;     claim that you wrote the original software. If you use this software
+;     in a product, an acknowledgment in the product documentation would be
+;     appreciated but is not required.
+;  2. Altered source versions must be plainly marked as such, and must not be
+;     misrepresented as being the original software
+;  3. This notice may not be removed or altered from any source distribution.
+;
+;
+;
+;         http://www.zlib.net
+;         http://www.winimage.com/zLibDll
+;         http://www.muppetlabs.com/~breadbox/software/assembly.html
+;
+; to compile this file for infozip Zip, I use option:
+;   ml64.exe /Flgvmat64 /c /Zi /DINFOZIP gvmat64.asm
+;
+; to compile this file for zLib, I use option:
+;   ml64.exe /Flgvmat64 /c /Zi gvmat64.asm
+; Be carrefull to adapt zlib1222add below to your version of zLib
+;   (if you use a version of zLib before 1.0.4 or after 1.2.2.2, change
+;    value of zlib1222add later)
+;
+; This file compile with Microsoft Macro Assembler (x64) for AMD64
+;
+;   ml64.exe is given with Visual Studio 2005/2008/2010 and Windows WDK
+;
+;   (you can get Windows WDK with ml64 for AMD64 from
+;      http://www.microsoft.com/whdc/Devtools/wdk/default.mspx for low price)
+;
+
+
+;uInt longest_match(s, cur_match)
+;    deflate_state *s;
+;    IPos cur_match;                             /* current match */
+.code
+longest_match PROC
+
+
+;LocalVarsSize   equ 88
+ LocalVarsSize   equ 72
+
+; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
+; free register :  r14,r15
+; register can be saved : rsp
+
+ chainlenwmask   equ  rsp + 8 - LocalVarsSize    ; high word: current chain len
+                                                 ; low word: s->wmask
+;window          equ  rsp + xx - LocalVarsSize   ; local copy of s->window ; stored in r10
+;windowbestlen   equ  rsp + xx - LocalVarsSize   ; s->window + bestlen , use r10+r11
+;scanstart       equ  rsp + xx - LocalVarsSize   ; first two bytes of string ; stored in r12w
+;scanend         equ  rsp + xx - LocalVarsSize   ; last two bytes of string use ebx
+;scanalign       equ  rsp + xx - LocalVarsSize   ; dword-misalignment of string r13
+;bestlen         equ  rsp + xx - LocalVarsSize   ; size of best match so far -> r11d
+;scan            equ  rsp + xx - LocalVarsSize   ; ptr to string wanting match -> r9
+IFDEF INFOZIP
+ELSE
+ nicematch       equ  (rsp + 16 - LocalVarsSize) ; a good enough match size
+ENDIF
+
+save_rdi        equ  rsp + 24 - LocalVarsSize
+save_rsi        equ  rsp + 32 - LocalVarsSize
+save_rbx        equ  rsp + 40 - LocalVarsSize
+save_rbp        equ  rsp + 48 - LocalVarsSize
+save_r12        equ  rsp + 56 - LocalVarsSize
+save_r13        equ  rsp + 64 - LocalVarsSize
+;save_r14        equ  rsp + 72 - LocalVarsSize
+;save_r15        equ  rsp + 80 - LocalVarsSize
+
+
+; summary of register usage
+; scanend     ebx
+; scanendw    bx
+; chainlenwmask   edx
+; curmatch    rsi
+; curmatchd   esi
+; windowbestlen   r8
+; scanalign   r9
+; scanalignd  r9d
+; window      r10
+; bestlen     r11
+; bestlend    r11d
+; scanstart   r12d
+; scanstartw  r12w
+; scan        r13
+; nicematch   r14d
+; limit       r15
+; limitd      r15d
+; prev        rcx
+
+;  all the +4 offsets are due to the addition of pending_buf_size (in zlib
+;  in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, remove the +4).
+;  Note : these value are good with a 8 bytes boundary pack structure
+
+
+    MAX_MATCH           equ     258
+    MIN_MATCH           equ     3
+    MIN_LOOKAHEAD       equ     (MAX_MATCH+MIN_MATCH+1)
+
+
+;;; Offsets for fields in the deflate_state structure. These numbers
+;;; are calculated from the definition of deflate_state, with the
+;;; assumption that the compiler will dword-align the fields. (Thus,
+;;; changing the definition of deflate_state could easily cause this
+;;; program to crash horribly, without so much as a warning at
+;;; compile time. Sigh.)
+
+;  all the +zlib1222add offsets are due to the addition of fields
+;  in zlib in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
+;  (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
+;  if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
+
+
+IFDEF INFOZIP
+
+_DATA   SEGMENT
+COMM    window_size:DWORD
+; WMask ; 7fff
+COMM    window:BYTE:010040H
+COMM    prev:WORD:08000H
+; MatchLen : unused
+; PrevMatch : unused
+COMM    strstart:DWORD
+COMM    match_start:DWORD
+; Lookahead : ignore
+COMM    prev_length:DWORD ; PrevLen
+COMM    max_chain_length:DWORD
+COMM    good_match:DWORD
+COMM    nice_match:DWORD
+prev_ad equ OFFSET prev
+window_ad equ OFFSET window
+nicematch equ nice_match
+_DATA ENDS
+WMask equ 07fffh
+
+ELSE
+
+  IFNDEF zlib1222add
+    zlib1222add equ 8
+  ENDIF
+dsWSize         equ 56+zlib1222add+(zlib1222add/2)
+dsWMask         equ 64+zlib1222add+(zlib1222add/2)
+dsWindow        equ 72+zlib1222add
+dsPrev          equ 88+zlib1222add
+dsMatchLen      equ 128+zlib1222add
+dsPrevMatch     equ 132+zlib1222add
+dsStrStart      equ 140+zlib1222add
+dsMatchStart    equ 144+zlib1222add
+dsLookahead     equ 148+zlib1222add
+dsPrevLen       equ 152+zlib1222add
+dsMaxChainLen   equ 156+zlib1222add
+dsGoodMatch     equ 172+zlib1222add
+dsNiceMatch     equ 176+zlib1222add
+
+window_size     equ [ rcx + dsWSize]
+WMask           equ [ rcx + dsWMask]
+window_ad       equ [ rcx + dsWindow]
+prev_ad         equ [ rcx + dsPrev]
+strstart        equ [ rcx + dsStrStart]
+match_start     equ [ rcx + dsMatchStart]
+Lookahead       equ [ rcx + dsLookahead] ; 0ffffffffh on infozip
+prev_length     equ [ rcx + dsPrevLen]
+max_chain_length equ [ rcx + dsMaxChainLen]
+good_match      equ [ rcx + dsGoodMatch]
+nice_match      equ [ rcx + dsNiceMatch]
+ENDIF
+
+; parameter 1 in r8(deflate state s), param 2 in rdx (cur match)
+
+; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
+; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
+;
+; All registers must be preserved across the call, except for
+;   rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
+
+
+
+;;; Save registers that the compiler may be using, and adjust esp to
+;;; make room for our stack frame.
+
+
+;;; Retrieve the function arguments. r8d will hold cur_match
+;;; throughout the entire function. edx will hold the pointer to the
+;;; deflate_state structure during the function's setup (before
+;;; entering the main loop.
+
+; parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
+
+; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
+
+        mov [save_rdi],rdi
+        mov [save_rsi],rsi
+        mov [save_rbx],rbx
+        mov [save_rbp],rbp
+IFDEF INFOZIP
+        mov r8d,ecx
+ELSE
+        mov r8d,edx
+ENDIF
+        mov [save_r12],r12
+        mov [save_r13],r13
+;        mov [save_r14],r14
+;        mov [save_r15],r15
+
+
+;;; uInt wmask = s->w_mask;
+;;; unsigned chain_length = s->max_chain_length;
+;;; if (s->prev_length >= s->good_match) {
+;;;     chain_length >>= 2;
+;;; }
+
+        mov edi, prev_length
+        mov esi, good_match
+        mov eax, WMask
+        mov ebx, max_chain_length
+        cmp edi, esi
+        jl  LastMatchGood
+        shr ebx, 2
+LastMatchGood:
+
+;;; chainlen is decremented once beforehand so that the function can
+;;; use the sign flag instead of the zero flag for the exit test.
+;;; It is then shifted into the high word, to make room for the wmask
+;;; value, which it will always accompany.
+
+        dec ebx
+        shl ebx, 16
+        or  ebx, eax
+
+;;; on zlib only
+;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
+
+IFDEF INFOZIP
+        mov [chainlenwmask], ebx
+; on infozip nice_match = [nice_match]
+ELSE
+        mov eax, nice_match
+        mov [chainlenwmask], ebx
+        mov r10d, Lookahead
+        cmp r10d, eax
+        cmovnl r10d, eax
+        mov [nicematch],r10d
+ENDIF
+
+;;; register Bytef *scan = s->window + s->strstart;
+        mov r10, window_ad
+        mov ebp, strstart
+        lea r13, [r10 + rbp]
+
+;;; Determine how many bytes the scan ptr is off from being
+;;; dword-aligned.
+
+         mov r9,r13
+         neg r13
+         and r13,3
+
+;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+;;;     s->strstart - (IPos)MAX_DIST(s) : NIL;
+IFDEF INFOZIP
+        mov eax,07efah ; MAX_DIST = (WSIZE-MIN_LOOKAHEAD) (0x8000-(3+8+1))
+ELSE
+        mov eax, window_size
+        sub eax, MIN_LOOKAHEAD
+ENDIF
+        xor edi,edi
+        sub ebp, eax
+
+        mov r11d, prev_length
+
+        cmovng ebp,edi
+
+;;; int best_len = s->prev_length;
+
+
+;;; Store the sum of s->window + best_len in esi locally, and in esi.
+
+       lea  rsi,[r10+r11]
+
+;;; register ush scan_start = *(ushf*)scan;
+;;; register ush scan_end   = *(ushf*)(scan+best_len-1);
+;;; Posf *prev = s->prev;
+
+        movzx r12d,word ptr [r9]
+        movzx ebx, word ptr [r9 + r11 - 1]
+
+        mov rdi, prev_ad
+
+;;; Jump into the main loop.
+
+        mov edx, [chainlenwmask]
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+
+LookupLoop1:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry1:
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+
+LookupLoop2:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry2:
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+
+LookupLoop4:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry4:
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jnz LookupLoop1
+        jmp LookupLoopIsZero
+
+
+;;; do {
+;;;     match = s->window + cur_match;
+;;;     if (*(ushf*)(match+best_len-1) != scan_end ||
+;;;         *(ushf*)match != scan_start) continue;
+;;;     [...]
+;;; } while ((cur_match = prev[cur_match & wmask]) > limit
+;;;          && --chain_length != 0);
+;;;
+;;; Here is the inner loop of the function. The function will spend the
+;;; majority of its time in this loop, and majority of that time will
+;;; be spent in the first ten instructions.
+;;;
+;;; Within this loop:
+;;; ebx = scanend
+;;; r8d = curmatch
+;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
+;;; esi = windowbestlen - i.e., (window + bestlen)
+;;; edi = prev
+;;; ebp = limit
+
+LookupLoop:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry:
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jnz LookupLoop1
+LookupLoopIsZero:
+        cmp     r12w, word ptr [r10 + r8]
+        jnz LookupLoop1
+
+
+;;; Store the current value of chainlen.
+        mov [chainlenwmask], edx
+
+;;; Point edi to the string under scrutiny, and esi to the string we
+;;; are hoping to match it up with. In actuality, esi and edi are
+;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
+;;; initialized to -(MAX_MATCH_8 - scanalign).
+
+        lea rsi,[r8+r10]
+        mov rdx, 0fffffffffffffef8h; -(MAX_MATCH_8)
+        lea rsi, [rsi + r13 + 0108h] ;MAX_MATCH_8]
+        lea rdi, [r9 + r13 + 0108h] ;MAX_MATCH_8]
+
+        prefetcht1 [rsi+rdx]
+        prefetcht1 [rdi+rdx]
+
+
+;;; Test the strings for equality, 8 bytes at a time. At the end,
+;;; adjust rdx so that it is offset to the exact byte that mismatched.
+;;;
+;;; We already know at this point that the first three bytes of the
+;;; strings match each other, and they can be safely passed over before
+;;; starting the compare loop. So what this code does is skip over 0-3
+;;; bytes, as much as necessary in order to dword-align the edi
+;;; pointer. (rsi will still be misaligned three times out of four.)
+;;;
+;;; It should be confessed that this loop usually does not represent
+;;; much of the total running time. Replacing it with a more
+;;; straightforward "rep cmpsb" would not drastically degrade
+;;; performance.
+
+
+LoopCmps:
+        mov rax, [rsi + rdx]
+        xor rax, [rdi + rdx]
+        jnz LeaveLoopCmps
+
+        mov rax, [rsi + rdx + 8]
+        xor rax, [rdi + rdx + 8]
+        jnz LeaveLoopCmps8
+
+
+        mov rax, [rsi + rdx + 8+8]
+        xor rax, [rdi + rdx + 8+8]
+        jnz LeaveLoopCmps16
+
+        add rdx,8+8+8
+
+        jnz short LoopCmps
+        jmp short LenMaximum
+LeaveLoopCmps16: add rdx,8
+LeaveLoopCmps8: add rdx,8
+LeaveLoopCmps:
+
+        test    eax, 0000FFFFh
+        jnz LenLower
+
+        test eax,0ffffffffh
+
+        jnz LenLower32
+
+        add rdx,4
+        shr rax,32
+        or ax,ax
+        jnz LenLower
+
+LenLower32:
+        shr eax,16
+        add rdx,2
+LenLower:   sub al, 1
+        adc rdx, 0
+;;; Calculate the length of the match. If it is longer than MAX_MATCH,
+;;; then automatically accept it as the best possible match and leave.
+
+        lea rax, [rdi + rdx]
+        sub rax, r9
+        cmp eax, MAX_MATCH
+        jge LenMaximum
+
+;;; If the length of the match is not longer than the best match we
+;;; have so far, then forget it and return to the lookup loop.
+;///////////////////////////////////
+
+        cmp eax, r11d
+        jg  LongerMatch
+
+        lea rsi,[r10+r11]
+
+        mov rdi, prev_ad
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;;         s->match_start = cur_match;
+;;;         best_len = len;
+;;;         if (len >= nice_match) break;
+;;;         scan_end = *(ushf*)(scan+best_len-1);
+
+LongerMatch:
+        mov r11d, eax
+        mov match_start, r8d
+        cmp eax, [nicematch]
+        jge LeaveNow
+
+        lea rsi,[r10+rax]
+
+        movzx   ebx, word ptr [r9 + rax - 1]
+        mov rdi, prev_ad
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;; Accept the current string, with the maximum possible length.
+
+LenMaximum:
+        mov r11d,MAX_MATCH
+        mov match_start, r8d
+
+;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+;;; return s->lookahead;
+
+LeaveNow:
+IFDEF INFOZIP
+        mov eax,r11d
+ELSE
+        mov eax, Lookahead
+        cmp r11d, eax
+        cmovng eax, r11d
+ENDIF
+
+;;; Restore the stack and return from whence we came.
+
+
+        mov rsi,[save_rsi]
+        mov rdi,[save_rdi]
+        mov rbx,[save_rbx]
+        mov rbp,[save_rbp]
+        mov r12,[save_r12]
+        mov r13,[save_r13]
+;        mov r14,[save_r14]
+;        mov r15,[save_r15]
+
+
+        ret 0
+; please don't remove this string !
+; Your can freely use gvmat64 in any free or commercial app
+; but it is far better don't remove the string in the binary!
+    db     0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998, converted to amd 64 by Gilles Vollant 2005",0dh,0ah,0
+longest_match   ENDP
+
+match_init PROC
+  ret 0
+match_init ENDP
+
+
+END
diff --git a/xs/src/png/zlib/contrib/masmx64/inffas8664.c b/xs/src/png/zlib/contrib/masmx64/inffas8664.c
new file mode 100644
index 000000000..aa861a333
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx64/inffas8664.c
@@ -0,0 +1,186 @@
+/* inffas8664.c is a hand tuned assembler version of inffast.c - fast decoding
+ * version for AMD64 on Windows using Microsoft C compiler
+ *
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Copyright (C) 2003 Chris Anderson <christop@charm.net>
+ * Please use the copyright conditions above.
+ *
+ * 2005 - Adaptation to Microsoft C Compiler for AMD64 by Gilles Vollant
+ *
+ * inffas8664.c call function inffas8664fnc in inffasx64.asm
+ *  inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
+ *
+ * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
+ * slightly quicker on x86 systems because, instead of using rep movsb to copy
+ * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
+ * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
+ * from http://fedora.linux.duke.edu/fc1_x86_64
+ * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
+ * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
+ * when decompressing mozilla-source-1.3.tar.gz.
+ *
+ * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
+ * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
+ * the moment.  I have successfully compiled and tested this code with gcc2.96,
+ * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
+ * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
+ * enabled.  I will attempt to merge the MMX code into this version.  Newer
+ * versions of this and inffast.S can be found at
+ * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
+ *
+ */
+
+#include <stdio.h>
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+/* Mark Adler's comments from inffast.c: */
+
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
+
+   Entry assumptions:
+
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+
+
+
+    typedef struct inffast_ar {
+/* 64   32                               x86  x86_64 */
+/* ar offset                              register */
+/*  0    0 */ void *esp;                /* esp save */
+/*  8    4 */ void *ebp;                /* ebp save */
+/* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
+/* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
+/* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
+/* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
+/* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
+/* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
+/* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
+/* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
+/* 80   40 */ size_t /*unsigned long */hold;       /* edx rdx  local strm->hold */
+/* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
+/* 92   48 */ unsigned wsize;           /*          window size */
+/* 96   52 */ unsigned write;           /*          window write index */
+/*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
+/*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
+/*108   64 */ unsigned len;             /*     r14  match length */
+/*112   68 */ unsigned dist;            /*     r15  match distance */
+/*116   72 */ unsigned status;          /*          set when state chng*/
+    } type_ar;
+#ifdef ASMINF
+
+void inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
+{
+    struct inflate_state FAR *state;
+    type_ar ar;
+    void inffas8664fnc(struct inffast_ar * par);
+
+
+
+#if (defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )) || (defined(_MSC_VER) && defined(_M_AMD64))
+#define PAD_AVAIL_IN 6
+#define PAD_AVAIL_OUT 258
+#else
+#define PAD_AVAIL_IN 5
+#define PAD_AVAIL_OUT 257
+#endif
+
+    /* copy state to local variables */
+    state = (struct inflate_state FAR *)strm->state;
+
+    ar.in = strm->next_in;
+    ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
+    ar.out = strm->next_out;
+    ar.beg = ar.out - (start - strm->avail_out);
+    ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
+    ar.wsize = state->wsize;
+    ar.write = state->wnext;
+    ar.window = state->window;
+    ar.hold = state->hold;
+    ar.bits = state->bits;
+    ar.lcode = state->lencode;
+    ar.dcode = state->distcode;
+    ar.lmask = (1U << state->lenbits) - 1;
+    ar.dmask = (1U << state->distbits) - 1;
+
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
+
+    /* align in on 1/2 hold size boundary */
+    while (((size_t)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
+        ar.hold += (unsigned long)*ar.in++ << ar.bits;
+        ar.bits += 8;
+    }
+
+    inffas8664fnc(&ar);
+
+    if (ar.status > 1) {
+        if (ar.status == 2)
+            strm->msg = "invalid literal/length code";
+        else if (ar.status == 3)
+            strm->msg = "invalid distance code";
+        else
+            strm->msg = "invalid distance too far back";
+        state->mode = BAD;
+    }
+    else if ( ar.status == 1 ) {
+        state->mode = TYPE;
+    }
+
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    ar.len = ar.bits >> 3;
+    ar.in -= ar.len;
+    ar.bits -= ar.len << 3;
+    ar.hold &= (1U << ar.bits) - 1;
+
+    /* update state and return */
+    strm->next_in = ar.in;
+    strm->next_out = ar.out;
+    strm->avail_in = (unsigned)(ar.in < ar.last ?
+                                PAD_AVAIL_IN + (ar.last - ar.in) :
+                                PAD_AVAIL_IN - (ar.in - ar.last));
+    strm->avail_out = (unsigned)(ar.out < ar.end ?
+                                 PAD_AVAIL_OUT + (ar.end - ar.out) :
+                                 PAD_AVAIL_OUT - (ar.out - ar.end));
+    state->hold = (unsigned long)ar.hold;
+    state->bits = ar.bits;
+    return;
+}
+
+#endif
diff --git a/xs/src/png/zlib/contrib/masmx64/inffasx64.asm b/xs/src/png/zlib/contrib/masmx64/inffasx64.asm
new file mode 100644
index 000000000..41ec82392
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx64/inffasx64.asm
@@ -0,0 +1,396 @@
+; inffasx64.asm is a hand tuned assembler version of inffast.c - fast decoding
+; version for AMD64 on Windows using Microsoft C compiler
+;
+; inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
+; inffasx64.asm is called by inffas8664.c, which contain more info.
+
+
+; to compile this file, I use option
+;   ml64.exe /Flinffasx64 /c /Zi inffasx64.asm
+;   with Microsoft Macro Assembler (x64) for AMD64
+;
+
+; This file compile with Microsoft Macro Assembler (x64) for AMD64
+;
+;   ml64.exe is given with Visual Studio 2005/2008/2010 and Windows WDK
+;
+;   (you can get Windows WDK with ml64 for AMD64 from
+;      http://www.microsoft.com/whdc/Devtools/wdk/default.mspx for low price)
+;
+
+
+.code
+inffas8664fnc PROC
+
+; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
+; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
+;
+; All registers must be preserved across the call, except for
+;   rax, rcx, rdx, r8, r-9, r10, and r11, which are scratch.
+
+
+	mov [rsp-8],rsi
+	mov [rsp-16],rdi
+	mov [rsp-24],r12
+	mov [rsp-32],r13
+	mov [rsp-40],r14
+	mov [rsp-48],r15
+	mov [rsp-56],rbx
+
+	mov rax,rcx
+
+	mov	[rax+8], rbp       ; /* save regs rbp and rsp */
+	mov	[rax], rsp
+
+	mov	rsp, rax          ; /* make rsp point to &ar */
+
+	mov	rsi, [rsp+16]      ; /* rsi  = in */
+	mov	rdi, [rsp+32]      ; /* rdi  = out */
+	mov	r9, [rsp+24]       ; /* r9   = last */
+	mov	r10, [rsp+48]      ; /* r10  = end */
+	mov	rbp, [rsp+64]      ; /* rbp  = lcode */
+	mov	r11, [rsp+72]      ; /* r11  = dcode */
+	mov	rdx, [rsp+80]      ; /* rdx  = hold */
+	mov	ebx, [rsp+88]      ; /* ebx  = bits */
+	mov	r12d, [rsp+100]    ; /* r12d = lmask */
+	mov	r13d, [rsp+104]    ; /* r13d = dmask */
+                                          ; /* r14d = len */
+                                          ; /* r15d = dist */
+
+
+	cld
+	cmp	r10, rdi
+	je	L_one_time           ; /* if only one decode left */
+	cmp	r9, rsi
+
+    jne L_do_loop
+
+
+L_one_time:
+	mov	r8, r12           ; /* r8 = lmask */
+	cmp	bl, 32
+	ja	L_get_length_code_one_time
+
+	lodsd                         ; /* eax = *(uint *)in++ */
+	mov	cl, bl            ; /* cl = bits, needs it for shifting */
+	add	bl, 32             ; /* bits += 32 */
+	shl	rax, cl
+	or	rdx, rax          ; /* hold |= *((uint *)in)++ << bits */
+	jmp	L_get_length_code_one_time
+
+ALIGN 4
+L_while_test:
+	cmp	r10, rdi
+	jbe	L_break_loop
+	cmp	r9, rsi
+	jbe	L_break_loop
+
+L_do_loop:
+	mov	r8, r12           ; /* r8 = lmask */
+	cmp	bl, 32
+	ja	L_get_length_code    ; /* if (32 < bits) */
+
+	lodsd                         ; /* eax = *(uint *)in++ */
+	mov	cl, bl            ; /* cl = bits, needs it for shifting */
+	add	bl, 32             ; /* bits += 32 */
+	shl	rax, cl
+	or	rdx, rax          ; /* hold |= *((uint *)in)++ << bits */
+
+L_get_length_code:
+	and	r8, rdx            ; /* r8 &= hold */
+	mov	eax, [rbp+r8*4]  ; /* eax = lcode[hold & lmask] */
+
+	mov	cl, ah            ; /* cl = this.bits */
+	sub	bl, ah            ; /* bits -= this.bits */
+	shr	rdx, cl           ; /* hold >>= this.bits */
+
+	test	al, al
+	jnz	L_test_for_length_base ; /* if (op != 0) 45.7% */
+
+	mov	r8, r12            ; /* r8 = lmask */
+	shr	eax, 16            ; /* output this.val char */
+	stosb
+
+L_get_length_code_one_time:
+	and	r8, rdx            ; /* r8 &= hold */
+	mov	eax, [rbp+r8*4] ; /* eax = lcode[hold & lmask] */
+
+L_dolen:
+	mov	cl, ah            ; /* cl = this.bits */
+	sub	bl, ah            ; /* bits -= this.bits */
+	shr	rdx, cl           ; /* hold >>= this.bits */
+
+	test	al, al
+	jnz	L_test_for_length_base ; /* if (op != 0) 45.7% */
+
+	shr	eax, 16            ; /* output this.val char */
+	stosb
+	jmp	L_while_test
+
+ALIGN 4
+L_test_for_length_base:
+	mov	r14d, eax         ; /* len = this */
+	shr	r14d, 16           ; /* len = this.val */
+	mov	cl, al
+
+	test	al, 16
+	jz	L_test_for_second_level_length ; /* if ((op & 16) == 0) 8% */
+	and	cl, 15             ; /* op &= 15 */
+	jz	L_decode_distance    ; /* if (!op) */
+
+L_add_bits_to_len:
+	sub	bl, cl
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx          ; /* eax &= hold */
+	shr	rdx, cl
+	add	r14d, eax         ; /* len += hold & mask[op] */
+
+L_decode_distance:
+	mov	r8, r13           ; /* r8 = dmask */
+	cmp	bl, 32
+	ja	L_get_distance_code  ; /* if (32 < bits) */
+
+	lodsd                         ; /* eax = *(uint *)in++ */
+	mov	cl, bl            ; /* cl = bits, needs it for shifting */
+	add	bl, 32             ; /* bits += 32 */
+	shl	rax, cl
+	or	rdx, rax          ; /* hold |= *((uint *)in)++ << bits */
+
+L_get_distance_code:
+	and	r8, rdx           ; /* r8 &= hold */
+	mov	eax, [r11+r8*4] ; /* eax = dcode[hold & dmask] */
+
+L_dodist:
+	mov	r15d, eax         ; /* dist = this */
+	shr	r15d, 16           ; /* dist = this.val */
+	mov	cl, ah
+	sub	bl, ah            ; /* bits -= this.bits */
+	shr	rdx, cl           ; /* hold >>= this.bits */
+	mov	cl, al            ; /* cl = this.op */
+
+	test	al, 16             ; /* if ((op & 16) == 0) */
+	jz	L_test_for_second_level_dist
+	and	cl, 15             ; /* op &= 15 */
+	jz	L_check_dist_one
+
+L_add_bits_to_dist:
+	sub	bl, cl
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax                 ; /* (1 << op) - 1 */
+	and	eax, edx          ; /* eax &= hold */
+	shr	rdx, cl
+	add	r15d, eax         ; /* dist += hold & ((1 << op) - 1) */
+
+L_check_window:
+	mov	r8, rsi           ; /* save in so from can use it's reg */
+	mov	rax, rdi
+	sub	rax, [rsp+40]      ; /* nbytes = out - beg */
+
+	cmp	eax, r15d
+	jb	L_clip_window        ; /* if (dist > nbytes) 4.2% */
+
+	mov	ecx, r14d         ; /* ecx = len */
+	mov	rsi, rdi
+	sub	rsi, r15          ; /* from = out - dist */
+
+	sar	ecx, 1
+	jnc	L_copy_two           ; /* if len % 2 == 0 */
+
+	rep     movsw
+	mov	al, [rsi]
+	mov	[rdi], al
+	inc	rdi
+
+	mov	rsi, r8           ; /* move in back to %rsi, toss from */
+	jmp	L_while_test
+
+L_copy_two:
+	rep     movsw
+	mov	rsi, r8           ; /* move in back to %rsi, toss from */
+	jmp	L_while_test
+
+ALIGN 4
+L_check_dist_one:
+	cmp	r15d, 1            ; /* if dist 1, is a memset */
+	jne	L_check_window
+	cmp	[rsp+40], rdi      ; /* if out == beg, outside window */
+	je	L_check_window
+
+	mov	ecx, r14d         ; /* ecx = len */
+	mov	al, [rdi-1]
+	mov	ah, al
+
+	sar	ecx, 1
+	jnc	L_set_two
+	mov	[rdi], al
+	inc	rdi
+
+L_set_two:
+	rep     stosw
+	jmp	L_while_test
+
+ALIGN 4
+L_test_for_second_level_length:
+	test	al, 64
+	jnz	L_test_for_end_of_block ; /* if ((op & 64) != 0) */
+
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx         ; /* eax &= hold */
+	add	eax, r14d        ; /* eax += len */
+	mov	eax, [rbp+rax*4] ; /* eax = lcode[val+(hold&mask[op])]*/
+	jmp	L_dolen
+
+ALIGN 4
+L_test_for_second_level_dist:
+	test	al, 64
+	jnz	L_invalid_distance_code ; /* if ((op & 64) != 0) */
+
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx         ; /* eax &= hold */
+	add	eax, r15d        ; /* eax += dist */
+	mov	eax, [r11+rax*4] ; /* eax = dcode[val+(hold&mask[op])]*/
+	jmp	L_dodist
+
+ALIGN 4
+L_clip_window:
+	mov	ecx, eax         ; /* ecx = nbytes */
+	mov	eax, [rsp+92]     ; /* eax = wsize, prepare for dist cmp */
+	neg	ecx                ; /* nbytes = -nbytes */
+
+	cmp	eax, r15d
+	jb	L_invalid_distance_too_far ; /* if (dist > wsize) */
+
+	add	ecx, r15d         ; /* nbytes = dist - nbytes */
+	cmp	dword ptr [rsp+96], 0
+	jne	L_wrap_around_window ; /* if (write != 0) */
+
+	mov	rsi, [rsp+56]     ; /* from  = window */
+	sub	eax, ecx         ; /* eax  -= nbytes */
+	add	rsi, rax         ; /* from += wsize - nbytes */
+
+	mov	eax, r14d        ; /* eax = len */
+	cmp	r14d, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* eax -= nbytes */
+	rep     movsb
+	mov	rsi, rdi
+	sub	rsi, r15         ; /* from = &out[ -dist ] */
+	jmp	L_do_copy
+
+ALIGN 4
+L_wrap_around_window:
+	mov	eax, [rsp+96]     ; /* eax = write */
+	cmp	ecx, eax
+	jbe	L_contiguous_in_window ; /* if (write >= nbytes) */
+
+	mov	esi, [rsp+92]     ; /* from  = wsize */
+	add	rsi, [rsp+56]     ; /* from += window */
+	add	rsi, rax         ; /* from += write */
+	sub	rsi, rcx         ; /* from -= nbytes */
+	sub	ecx, eax         ; /* nbytes -= write */
+
+	mov	eax, r14d        ; /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* len -= nbytes */
+	rep     movsb
+	mov	rsi, [rsp+56]     ; /* from = window */
+	mov	ecx, [rsp+96]     ; /* nbytes = write */
+	cmp	eax, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* len -= nbytes */
+	rep     movsb
+	mov	rsi, rdi
+	sub	rsi, r15         ; /* from = out - dist */
+	jmp	L_do_copy
+
+ALIGN 4
+L_contiguous_in_window:
+	mov	rsi, [rsp+56]     ; /* rsi = window */
+	add	rsi, rax
+	sub	rsi, rcx         ; /* from += write - nbytes */
+
+	mov	eax, r14d        ; /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* len -= nbytes */
+	rep     movsb
+	mov	rsi, rdi
+	sub	rsi, r15         ; /* from = out - dist */
+	jmp	L_do_copy           ; /* if (nbytes >= len) */
+
+ALIGN 4
+L_do_copy:
+	mov	ecx, eax         ; /* ecx = len */
+	rep     movsb
+
+	mov	rsi, r8          ; /* move in back to %esi, toss from */
+	jmp	L_while_test
+
+L_test_for_end_of_block:
+	test	al, 32
+	jz	L_invalid_literal_length_code
+	mov	dword ptr [rsp+116], 1
+	jmp	L_break_loop_with_status
+
+L_invalid_literal_length_code:
+	mov	dword ptr [rsp+116], 2
+	jmp	L_break_loop_with_status
+
+L_invalid_distance_code:
+	mov	dword ptr [rsp+116], 3
+	jmp	L_break_loop_with_status
+
+L_invalid_distance_too_far:
+	mov	dword ptr [rsp+116], 4
+	jmp	L_break_loop_with_status
+
+L_break_loop:
+	mov	dword ptr [rsp+116], 0
+
+L_break_loop_with_status:
+; /* put in, out, bits, and hold back into ar and pop esp */
+	mov	[rsp+16], rsi     ; /* in */
+	mov	[rsp+32], rdi     ; /* out */
+	mov	[rsp+88], ebx     ; /* bits */
+	mov	[rsp+80], rdx     ; /* hold */
+
+	mov	rax, [rsp]       ; /* restore rbp and rsp */
+	mov	rbp, [rsp+8]
+	mov	rsp, rax
+
+
+
+	mov rsi,[rsp-8]
+	mov rdi,[rsp-16]
+	mov r12,[rsp-24]
+	mov r13,[rsp-32]
+	mov r14,[rsp-40]
+	mov r15,[rsp-48]
+	mov rbx,[rsp-56]
+
+    ret 0
+;          :
+;          : "m" (ar)
+;          : "memory", "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi",
+;            "%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
+;    );
+
+inffas8664fnc 	ENDP
+;_TEXT	ENDS
+END
diff --git a/xs/src/png/zlib/contrib/masmx64/readme.txt b/xs/src/png/zlib/contrib/masmx64/readme.txt
new file mode 100644
index 000000000..652571c7a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx64/readme.txt
@@ -0,0 +1,31 @@
+Summary
+-------
+This directory contains ASM implementations of the functions
+longest_match() and inflate_fast(), for 64 bits x86 (both AMD64 and Intel EM64t),
+for use with Microsoft Macro Assembler (x64) for AMD64 and Microsoft C++ 64 bits.
+
+gvmat64.asm is written by Gilles Vollant (2005), by using Brian Raiter 686/32 bits
+   assembly optimized version from Jean-loup Gailly original longest_match function
+
+inffasx64.asm and inffas8664.c were written by Chris Anderson, by optimizing
+   original function from Mark Adler
+
+Use instructions
+----------------
+Assemble the .asm files using MASM and put the object files into the zlib source
+directory.  You can also get object files here:
+
+     http://www.winimage.com/zLibDll/zlib124_masm_obj.zip
+
+define ASMV and ASMINF in your project. Include inffas8664.c in your source tree,
+and inffasx64.obj and gvmat64.obj as object to link.
+
+
+Build instructions
+------------------
+run bld_64.bat with Microsoft Macro Assembler (x64) for AMD64 (ml64.exe)
+
+ml64.exe is given with Visual Studio 2005, Windows 2003 server DDK
+
+You can get Windows 2003 server DDK with ml64 and cl for AMD64 from
+  http://www.microsoft.com/whdc/devtools/ddk/default.mspx for low price)
diff --git a/xs/src/png/zlib/contrib/masmx86/bld_ml32.bat b/xs/src/png/zlib/contrib/masmx86/bld_ml32.bat
new file mode 100644
index 000000000..fcf5755e4
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx86/bld_ml32.bat
@@ -0,0 +1,2 @@
+ml /coff /Zi /c /Flmatch686.lst match686.asm
+ml /coff /Zi /c /Flinffas32.lst inffas32.asm
diff --git a/xs/src/png/zlib/contrib/masmx86/inffas32.asm b/xs/src/png/zlib/contrib/masmx86/inffas32.asm
new file mode 100644
index 000000000..cb37a81e4
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx86/inffas32.asm
@@ -0,0 +1,1080 @@
+;/* inffas32.asm is a hand tuned assembler version of inffast.c -- fast decoding
+; *
+; * inffas32.asm is derivated from inffas86.c, with translation of assembly code
+; *
+; * Copyright (C) 1995-2003 Mark Adler
+; * For conditions of distribution and use, see copyright notice in zlib.h
+; *
+; * Copyright (C) 2003 Chris Anderson <christop@charm.net>
+; * Please use the copyright conditions above.
+; *
+; * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
+; * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
+; * the moment.  I have successfully compiled and tested this code with gcc2.96,
+; * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
+; * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
+; * enabled.  I will attempt to merge the MMX code into this version.  Newer
+; * versions of this and inffast.S can be found at
+; * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
+; *
+; * 2005 : modification by Gilles Vollant
+; */
+; For Visual C++ 4.x and higher and ML 6.x and higher
+;   ml.exe is in directory \MASM611C of Win95 DDK
+;   ml.exe is also distributed in http://www.masm32.com/masmdl.htm
+;    and in VC++2003 toolkit at http://msdn.microsoft.com/visualc/vctoolkit2003/
+;
+;
+;   compile with command line option
+;   ml  /coff /Zi /c /Flinffas32.lst inffas32.asm
+
+;   if you define NO_GZIP (see inflate.h), compile with
+;   ml  /coff /Zi /c /Flinffas32.lst /DNO_GUNZIP inffas32.asm
+
+
+; zlib122sup is 0 fort zlib 1.2.2.1 and lower
+; zlib122sup is 8 fort zlib 1.2.2.2 and more (with addition of dmax and head
+;        in inflate_state in inflate.h)
+zlib1222sup      equ    8
+
+
+IFDEF GUNZIP
+  INFLATE_MODE_TYPE    equ 11
+  INFLATE_MODE_BAD     equ 26
+ELSE
+  IFNDEF NO_GUNZIP
+    INFLATE_MODE_TYPE    equ 11
+    INFLATE_MODE_BAD     equ 26
+  ELSE
+    INFLATE_MODE_TYPE    equ 3
+    INFLATE_MODE_BAD     equ 17
+  ENDIF
+ENDIF
+
+
+; 75 "inffast.S"
+;FILE "inffast.S"
+
+;;;GLOBAL _inflate_fast
+
+;;;SECTION .text
+
+
+
+	.586p
+	.mmx
+
+	name	inflate_fast_x86
+	.MODEL	FLAT
+
+_DATA			segment
+inflate_fast_use_mmx:
+	dd	1
+
+
+_TEXT			segment
+
+
+
+ALIGN 4
+	db	'Fast decoding Code from Chris Anderson'
+	db	0
+
+ALIGN 4
+invalid_literal_length_code_msg:
+	db	'invalid literal/length code'
+	db	0
+
+ALIGN 4
+invalid_distance_code_msg:
+	db	'invalid distance code'
+	db	0
+
+ALIGN 4
+invalid_distance_too_far_msg:
+	db	'invalid distance too far back'
+	db	0
+
+
+ALIGN 4
+inflate_fast_mask:
+dd	0
+dd	1
+dd	3
+dd	7
+dd	15
+dd	31
+dd	63
+dd	127
+dd	255
+dd	511
+dd	1023
+dd	2047
+dd	4095
+dd	8191
+dd	16383
+dd	32767
+dd	65535
+dd	131071
+dd	262143
+dd	524287
+dd	1048575
+dd	2097151
+dd	4194303
+dd	8388607
+dd	16777215
+dd	33554431
+dd	67108863
+dd	134217727
+dd	268435455
+dd	536870911
+dd	1073741823
+dd	2147483647
+dd	4294967295
+
+
+mode_state	 equ	0	;/* state->mode	*/
+wsize_state	 equ	(32+zlib1222sup)	;/* state->wsize */
+write_state	 equ	(36+4+zlib1222sup)	;/* state->write */
+window_state	 equ	(40+4+zlib1222sup)	;/* state->window */
+hold_state	 equ	(44+4+zlib1222sup)	;/* state->hold	*/
+bits_state	 equ	(48+4+zlib1222sup)	;/* state->bits	*/
+lencode_state	 equ	(64+4+zlib1222sup)	;/* state->lencode */
+distcode_state	 equ	(68+4+zlib1222sup)	;/* state->distcode */
+lenbits_state	 equ	(72+4+zlib1222sup)	;/* state->lenbits */
+distbits_state	 equ	(76+4+zlib1222sup)	;/* state->distbits */
+
+
+;;SECTION .text
+; 205 "inffast.S"
+;GLOBAL	inflate_fast_use_mmx
+
+;SECTION .data
+
+
+; GLOBAL inflate_fast_use_mmx:object
+;.size inflate_fast_use_mmx, 4
+; 226 "inffast.S"
+;SECTION .text
+
+ALIGN 4
+_inflate_fast proc near
+.FPO (16, 4, 0, 0, 1, 0)
+	push  edi
+	push  esi
+	push  ebp
+	push  ebx
+	pushfd
+	sub  esp,64
+	cld
+
+
+
+
+	mov  esi, [esp+88]
+	mov  edi, [esi+28]
+
+
+
+
+
+
+
+	mov  edx, [esi+4]
+	mov  eax, [esi+0]
+
+	add  edx,eax
+	sub  edx,11
+
+	mov  [esp+44],eax
+	mov  [esp+20],edx
+
+	mov  ebp, [esp+92]
+	mov  ecx, [esi+16]
+	mov  ebx, [esi+12]
+
+	sub  ebp,ecx
+	neg  ebp
+	add  ebp,ebx
+
+	sub  ecx,257
+	add  ecx,ebx
+
+	mov  [esp+60],ebx
+	mov  [esp+40],ebp
+	mov  [esp+16],ecx
+; 285 "inffast.S"
+	mov  eax, [edi+lencode_state]
+	mov  ecx, [edi+distcode_state]
+
+	mov  [esp+8],eax
+	mov  [esp+12],ecx
+
+	mov  eax,1
+	mov  ecx, [edi+lenbits_state]
+	shl  eax,cl
+	dec  eax
+	mov  [esp+0],eax
+
+	mov  eax,1
+	mov  ecx, [edi+distbits_state]
+	shl  eax,cl
+	dec  eax
+	mov  [esp+4],eax
+
+	mov  eax, [edi+wsize_state]
+	mov  ecx, [edi+write_state]
+	mov  edx, [edi+window_state]
+
+	mov  [esp+52],eax
+	mov  [esp+48],ecx
+	mov  [esp+56],edx
+
+	mov  ebp, [edi+hold_state]
+	mov  ebx, [edi+bits_state]
+; 321 "inffast.S"
+	mov  esi, [esp+44]
+	mov  ecx, [esp+20]
+	cmp  ecx,esi
+	ja   L_align_long
+
+	add  ecx,11
+	sub  ecx,esi
+	mov  eax,12
+	sub  eax,ecx
+	lea  edi, [esp+28]
+	rep movsb
+	mov  ecx,eax
+	xor  eax,eax
+	rep stosb
+	lea  esi, [esp+28]
+	mov  [esp+20],esi
+	jmp  L_is_aligned
+
+
+L_align_long:
+	test  esi,3
+	jz   L_is_aligned
+	xor  eax,eax
+	mov  al, [esi]
+	inc  esi
+	mov  ecx,ebx
+	add  ebx,8
+	shl  eax,cl
+	or  ebp,eax
+	jmp L_align_long
+
+L_is_aligned:
+	mov  edi, [esp+60]
+; 366 "inffast.S"
+L_check_mmx:
+	cmp  dword ptr [inflate_fast_use_mmx],2
+	je   L_init_mmx
+	ja   L_do_loop
+
+	push  eax
+	push  ebx
+	push  ecx
+	push  edx
+	pushfd
+	mov  eax, [esp]
+	xor  dword ptr [esp],0200000h
+
+
+
+
+	popfd
+	pushfd
+	pop  edx
+	xor  edx,eax
+	jz   L_dont_use_mmx
+	xor  eax,eax
+	cpuid
+	cmp  ebx,0756e6547h
+	jne  L_dont_use_mmx
+	cmp  ecx,06c65746eh
+	jne  L_dont_use_mmx
+	cmp  edx,049656e69h
+	jne  L_dont_use_mmx
+	mov  eax,1
+	cpuid
+	shr  eax,8
+	and  eax,15
+	cmp  eax,6
+	jne  L_dont_use_mmx
+	test  edx,0800000h
+	jnz  L_use_mmx
+	jmp  L_dont_use_mmx
+L_use_mmx:
+	mov  dword ptr [inflate_fast_use_mmx],2
+	jmp  L_check_mmx_pop
+L_dont_use_mmx:
+	mov  dword ptr [inflate_fast_use_mmx],3
+L_check_mmx_pop:
+	pop  edx
+	pop  ecx
+	pop  ebx
+	pop  eax
+	jmp  L_check_mmx
+; 426 "inffast.S"
+ALIGN 4
+L_do_loop:
+; 437 "inffast.S"
+	cmp  bl,15
+	ja   L_get_length_code
+
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+
+L_get_length_code:
+	mov  edx, [esp+0]
+	mov  ecx, [esp+8]
+	and  edx,ebp
+	mov  eax, [ecx+edx*4]
+
+L_dolen:
+
+
+
+
+
+
+	mov  cl,ah
+	sub  bl,ah
+	shr  ebp,cl
+
+
+
+
+
+
+	test  al,al
+	jnz   L_test_for_length_base
+
+	shr  eax,16
+	stosb
+
+L_while_test:
+
+
+	cmp  [esp+16],edi
+	jbe  L_break_loop
+
+	cmp  [esp+20],esi
+	ja   L_do_loop
+	jmp  L_break_loop
+
+L_test_for_length_base:
+; 502 "inffast.S"
+	mov  edx,eax
+	shr  edx,16
+	mov  cl,al
+
+	test  al,16
+	jz   L_test_for_second_level_length
+	and  cl,15
+	jz   L_save_len
+	cmp  bl,cl
+	jae  L_add_bits_to_len
+
+	mov  ch,cl
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+	mov  cl,ch
+
+L_add_bits_to_len:
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	sub  bl,cl
+	and  eax,ebp
+	shr  ebp,cl
+	add  edx,eax
+
+L_save_len:
+	mov  [esp+24],edx
+
+
+L_decode_distance:
+; 549 "inffast.S"
+	cmp  bl,15
+	ja   L_get_distance_code
+
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+
+L_get_distance_code:
+	mov  edx, [esp+4]
+	mov  ecx, [esp+12]
+	and  edx,ebp
+	mov  eax, [ecx+edx*4]
+
+
+L_dodist:
+	mov  edx,eax
+	shr  edx,16
+	mov  cl,ah
+	sub  bl,ah
+	shr  ebp,cl
+; 584 "inffast.S"
+	mov  cl,al
+
+	test  al,16
+	jz  L_test_for_second_level_dist
+	and  cl,15
+	jz  L_check_dist_one
+	cmp  bl,cl
+	jae  L_add_bits_to_dist
+
+	mov  ch,cl
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+	mov  cl,ch
+
+L_add_bits_to_dist:
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	sub  bl,cl
+	and  eax,ebp
+	shr  ebp,cl
+	add  edx,eax
+	jmp  L_check_window
+
+L_check_window:
+; 625 "inffast.S"
+	mov  [esp+44],esi
+	mov  eax,edi
+	sub  eax, [esp+40]
+
+	cmp  eax,edx
+	jb   L_clip_window
+
+	mov  ecx, [esp+24]
+	mov  esi,edi
+	sub  esi,edx
+
+	sub  ecx,3
+	mov  al, [esi]
+	mov  [edi],al
+	mov  al, [esi+1]
+	mov  dl, [esi+2]
+	add  esi,3
+	mov  [edi+1],al
+	mov  [edi+2],dl
+	add  edi,3
+	rep movsb
+
+	mov  esi, [esp+44]
+	jmp  L_while_test
+
+ALIGN 4
+L_check_dist_one:
+	cmp  edx,1
+	jne  L_check_window
+	cmp  [esp+40],edi
+	je  L_check_window
+
+	dec  edi
+	mov  ecx, [esp+24]
+	mov  al, [edi]
+	sub  ecx,3
+
+	mov  [edi+1],al
+	mov  [edi+2],al
+	mov  [edi+3],al
+	add  edi,4
+	rep stosb
+
+	jmp  L_while_test
+
+ALIGN 4
+L_test_for_second_level_length:
+
+
+
+
+	test  al,64
+	jnz   L_test_for_end_of_block
+
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	and  eax,ebp
+	add  eax,edx
+	mov  edx, [esp+8]
+	mov  eax, [edx+eax*4]
+	jmp  L_dolen
+
+ALIGN 4
+L_test_for_second_level_dist:
+
+
+
+
+	test  al,64
+	jnz   L_invalid_distance_code
+
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	and  eax,ebp
+	add  eax,edx
+	mov  edx, [esp+12]
+	mov  eax, [edx+eax*4]
+	jmp  L_dodist
+
+ALIGN 4
+L_clip_window:
+; 721 "inffast.S"
+	mov  ecx,eax
+	mov  eax, [esp+52]
+	neg  ecx
+	mov  esi, [esp+56]
+
+	cmp  eax,edx
+	jb   L_invalid_distance_too_far
+
+	add  ecx,edx
+	cmp  dword ptr [esp+48],0
+	jne  L_wrap_around_window
+
+	sub  eax,ecx
+	add  esi,eax
+; 749 "inffast.S"
+	mov  eax, [esp+24]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+	jmp  L_do_copy1
+
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+	jmp  L_do_copy1
+
+L_wrap_around_window:
+; 793 "inffast.S"
+	mov  eax, [esp+48]
+	cmp  ecx,eax
+	jbe  L_contiguous_in_window
+
+	add  esi, [esp+52]
+	add  esi,eax
+	sub  esi,ecx
+	sub  ecx,eax
+
+
+	mov  eax, [esp+24]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi, [esp+56]
+	mov  ecx, [esp+48]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+	jmp  L_do_copy1
+
+L_contiguous_in_window:
+; 836 "inffast.S"
+	add  esi,eax
+	sub  esi,ecx
+
+
+	mov  eax, [esp+24]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+
+L_do_copy1:
+; 862 "inffast.S"
+	mov  ecx,eax
+	rep movsb
+
+	mov  esi, [esp+44]
+	jmp  L_while_test
+; 878 "inffast.S"
+ALIGN 4
+L_init_mmx:
+	emms
+
+
+
+
+
+	movd mm0,ebp
+	mov  ebp,ebx
+; 896 "inffast.S"
+	movd mm4,dword ptr [esp+0]
+	movq mm3,mm4
+	movd mm5,dword ptr [esp+4]
+	movq mm2,mm5
+	pxor mm1,mm1
+	mov  ebx, [esp+8]
+	jmp  L_do_loop_mmx
+
+ALIGN 4
+L_do_loop_mmx:
+	psrlq mm0,mm1
+
+	cmp  ebp,32
+	ja  L_get_length_code_mmx
+
+	movd mm6,ebp
+	movd mm7,dword ptr [esi]
+	add  esi,4
+	psllq mm7,mm6
+	add  ebp,32
+	por mm0,mm7
+
+L_get_length_code_mmx:
+	pand mm4,mm0
+	movd eax,mm4
+	movq mm4,mm3
+	mov  eax, [ebx+eax*4]
+
+L_dolen_mmx:
+	movzx  ecx,ah
+	movd mm1,ecx
+	sub  ebp,ecx
+
+	test  al,al
+	jnz L_test_for_length_base_mmx
+
+	shr  eax,16
+	stosb
+
+L_while_test_mmx:
+
+
+	cmp  [esp+16],edi
+	jbe L_break_loop
+
+	cmp  [esp+20],esi
+	ja L_do_loop_mmx
+	jmp L_break_loop
+
+L_test_for_length_base_mmx:
+
+	mov  edx,eax
+	shr  edx,16
+
+	test  al,16
+	jz  L_test_for_second_level_length_mmx
+	and  eax,15
+	jz L_decode_distance_mmx
+
+	psrlq mm0,mm1
+	movd mm1,eax
+	movd ecx,mm0
+	sub  ebp,eax
+	and  ecx, [inflate_fast_mask+eax*4]
+	add  edx,ecx
+
+L_decode_distance_mmx:
+	psrlq mm0,mm1
+
+	cmp  ebp,32
+	ja L_get_dist_code_mmx
+
+	movd mm6,ebp
+	movd mm7,dword ptr [esi]
+	add  esi,4
+	psllq mm7,mm6
+	add  ebp,32
+	por mm0,mm7
+
+L_get_dist_code_mmx:
+	mov  ebx, [esp+12]
+	pand mm5,mm0
+	movd eax,mm5
+	movq mm5,mm2
+	mov  eax, [ebx+eax*4]
+
+L_dodist_mmx:
+
+	movzx  ecx,ah
+	mov  ebx,eax
+	shr  ebx,16
+	sub  ebp,ecx
+	movd mm1,ecx
+
+	test  al,16
+	jz L_test_for_second_level_dist_mmx
+	and  eax,15
+	jz L_check_dist_one_mmx
+
+L_add_bits_to_dist_mmx:
+	psrlq mm0,mm1
+	movd mm1,eax
+	movd ecx,mm0
+	sub  ebp,eax
+	and  ecx, [inflate_fast_mask+eax*4]
+	add  ebx,ecx
+
+L_check_window_mmx:
+	mov  [esp+44],esi
+	mov  eax,edi
+	sub  eax, [esp+40]
+
+	cmp  eax,ebx
+	jb L_clip_window_mmx
+
+	mov  ecx,edx
+	mov  esi,edi
+	sub  esi,ebx
+
+	sub  ecx,3
+	mov  al, [esi]
+	mov  [edi],al
+	mov  al, [esi+1]
+	mov  dl, [esi+2]
+	add  esi,3
+	mov  [edi+1],al
+	mov  [edi+2],dl
+	add  edi,3
+	rep movsb
+
+	mov  esi, [esp+44]
+	mov  ebx, [esp+8]
+	jmp  L_while_test_mmx
+
+ALIGN 4
+L_check_dist_one_mmx:
+	cmp  ebx,1
+	jne  L_check_window_mmx
+	cmp  [esp+40],edi
+	je   L_check_window_mmx
+
+	dec  edi
+	mov  ecx,edx
+	mov  al, [edi]
+	sub  ecx,3
+
+	mov  [edi+1],al
+	mov  [edi+2],al
+	mov  [edi+3],al
+	add  edi,4
+	rep stosb
+
+	mov  ebx, [esp+8]
+	jmp  L_while_test_mmx
+
+ALIGN 4
+L_test_for_second_level_length_mmx:
+	test  al,64
+	jnz L_test_for_end_of_block
+
+	and  eax,15
+	psrlq mm0,mm1
+	movd ecx,mm0
+	and  ecx, [inflate_fast_mask+eax*4]
+	add  ecx,edx
+	mov  eax, [ebx+ecx*4]
+	jmp L_dolen_mmx
+
+ALIGN 4
+L_test_for_second_level_dist_mmx:
+	test  al,64
+	jnz L_invalid_distance_code
+
+	and  eax,15
+	psrlq mm0,mm1
+	movd ecx,mm0
+	and  ecx, [inflate_fast_mask+eax*4]
+	mov  eax, [esp+12]
+	add  ecx,ebx
+	mov  eax, [eax+ecx*4]
+	jmp  L_dodist_mmx
+
+ALIGN 4
+L_clip_window_mmx:
+
+	mov  ecx,eax
+	mov  eax, [esp+52]
+	neg  ecx
+	mov  esi, [esp+56]
+
+	cmp  eax,ebx
+	jb  L_invalid_distance_too_far
+
+	add  ecx,ebx
+	cmp  dword ptr [esp+48],0
+	jne  L_wrap_around_window_mmx
+
+	sub  eax,ecx
+	add  esi,eax
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+	jmp  L_do_copy1_mmx
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+	jmp  L_do_copy1_mmx
+
+L_wrap_around_window_mmx:
+
+	mov  eax, [esp+48]
+	cmp  ecx,eax
+	jbe  L_contiguous_in_window_mmx
+
+	add  esi, [esp+52]
+	add  esi,eax
+	sub  esi,ecx
+	sub  ecx,eax
+
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi, [esp+56]
+	mov  ecx, [esp+48]
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+	jmp  L_do_copy1_mmx
+
+L_contiguous_in_window_mmx:
+
+	add  esi,eax
+	sub  esi,ecx
+
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+
+L_do_copy1_mmx:
+
+
+	mov  ecx,edx
+	rep movsb
+
+	mov  esi, [esp+44]
+	mov  ebx, [esp+8]
+	jmp  L_while_test_mmx
+; 1174 "inffast.S"
+L_invalid_distance_code:
+
+
+
+
+
+	mov  ecx, invalid_distance_code_msg
+	mov  edx,INFLATE_MODE_BAD
+	jmp  L_update_stream_state
+
+L_test_for_end_of_block:
+
+
+
+
+
+	test  al,32
+	jz  L_invalid_literal_length_code
+
+	mov  ecx,0
+	mov  edx,INFLATE_MODE_TYPE
+	jmp  L_update_stream_state
+
+L_invalid_literal_length_code:
+
+
+
+
+
+	mov  ecx, invalid_literal_length_code_msg
+	mov  edx,INFLATE_MODE_BAD
+	jmp  L_update_stream_state
+
+L_invalid_distance_too_far:
+
+
+
+	mov  esi, [esp+44]
+	mov  ecx, invalid_distance_too_far_msg
+	mov  edx,INFLATE_MODE_BAD
+	jmp  L_update_stream_state
+
+L_update_stream_state:
+
+	mov  eax, [esp+88]
+	test  ecx,ecx
+	jz  L_skip_msg
+	mov  [eax+24],ecx
+L_skip_msg:
+	mov  eax, [eax+28]
+	mov  [eax+mode_state],edx
+	jmp  L_break_loop
+
+ALIGN 4
+L_break_loop:
+; 1243 "inffast.S"
+	cmp  dword ptr [inflate_fast_use_mmx],2
+	jne  L_update_next_in
+
+
+
+	mov  ebx,ebp
+
+L_update_next_in:
+; 1266 "inffast.S"
+	mov  eax, [esp+88]
+	mov  ecx,ebx
+	mov  edx, [eax+28]
+	shr  ecx,3
+	sub  esi,ecx
+	shl  ecx,3
+	sub  ebx,ecx
+	mov  [eax+12],edi
+	mov  [edx+bits_state],ebx
+	mov  ecx,ebx
+
+	lea  ebx, [esp+28]
+	cmp  [esp+20],ebx
+	jne  L_buf_not_used
+
+	sub  esi,ebx
+	mov  ebx, [eax+0]
+	mov  [esp+20],ebx
+	add  esi,ebx
+	mov  ebx, [eax+4]
+	sub  ebx,11
+	add  [esp+20],ebx
+
+L_buf_not_used:
+	mov  [eax+0],esi
+
+	mov  ebx,1
+	shl  ebx,cl
+	dec  ebx
+
+
+
+
+
+	cmp  dword ptr [inflate_fast_use_mmx],2
+	jne  L_update_hold
+
+
+
+	psrlq mm0,mm1
+	movd ebp,mm0
+
+	emms
+
+L_update_hold:
+
+
+
+	and  ebp,ebx
+	mov  [edx+hold_state],ebp
+
+
+
+
+	mov  ebx, [esp+20]
+	cmp  ebx,esi
+	jbe  L_last_is_smaller
+
+	sub  ebx,esi
+	add  ebx,11
+	mov  [eax+4],ebx
+	jmp  L_fixup_out
+L_last_is_smaller:
+	sub  esi,ebx
+	neg  esi
+	add  esi,11
+	mov  [eax+4],esi
+
+
+
+
+L_fixup_out:
+
+	mov  ebx, [esp+16]
+	cmp  ebx,edi
+	jbe  L_end_is_smaller
+
+	sub  ebx,edi
+	add  ebx,257
+	mov  [eax+16],ebx
+	jmp  L_done
+L_end_is_smaller:
+	sub  edi,ebx
+	neg  edi
+	add  edi,257
+	mov  [eax+16],edi
+
+
+
+
+
+L_done:
+	add  esp,64
+	popfd
+	pop  ebx
+	pop  ebp
+	pop  esi
+	pop  edi
+	ret
+_inflate_fast endp
+
+_TEXT	ends
+end
diff --git a/xs/src/png/zlib/contrib/masmx86/match686.asm b/xs/src/png/zlib/contrib/masmx86/match686.asm
new file mode 100644
index 000000000..69e0eed01
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx86/match686.asm
@@ -0,0 +1,479 @@
+; match686.asm -- Asm portion of the optimized longest_match for 32 bits x86
+; Copyright (C) 1995-1996 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
+; File written by Gilles Vollant, by converting match686.S from Brian Raiter
+; for MASM. This is as assembly version of longest_match
+;  from Jean-loup Gailly in deflate.c
+;
+;         http://www.zlib.net
+;         http://www.winimage.com/zLibDll
+;         http://www.muppetlabs.com/~breadbox/software/assembly.html
+;
+; For Visual C++ 4.x and higher and ML 6.x and higher
+;   ml.exe is distributed in
+;  http://www.microsoft.com/downloads/details.aspx?FamilyID=7a1c9da0-0510-44a2-b042-7ef370530c64
+;
+; this file contain two implementation of longest_match
+;
+;  this longest_match was written by Brian raiter (1998), optimized for Pentium Pro
+;   (and the faster known version of match_init on modern Core 2 Duo and AMD Phenom)
+;
+;  for using an assembly version of longest_match, you need define ASMV in project
+;
+;    compile the asm file running
+;           ml /coff /Zi /c /Flmatch686.lst match686.asm
+;    and do not include match686.obj in your project
+;
+; note: contrib of zLib 1.2.3 and earlier contained both a deprecated version for
+;  Pentium (prior Pentium Pro) and this version for Pentium Pro and modern processor
+;  with autoselect (with cpu detection code)
+;  if you want support the old pentium optimization, you can still use these version
+;
+; this file is not optimized for old pentium, but it compatible with all x86 32 bits
+; processor (starting 80386)
+;
+;
+; see below : zlib1222add must be adjuster if you use a zlib version < 1.2.2.2
+
+;uInt longest_match(s, cur_match)
+;    deflate_state *s;
+;    IPos cur_match;                             /* current match */
+
+    NbStack         equ     76
+    cur_match       equ     dword ptr[esp+NbStack-0]
+    str_s           equ     dword ptr[esp+NbStack-4]
+; 5 dword on top (ret,ebp,esi,edi,ebx)
+    adrret          equ     dword ptr[esp+NbStack-8]
+    pushebp         equ     dword ptr[esp+NbStack-12]
+    pushedi         equ     dword ptr[esp+NbStack-16]
+    pushesi         equ     dword ptr[esp+NbStack-20]
+    pushebx         equ     dword ptr[esp+NbStack-24]
+
+    chain_length    equ     dword ptr [esp+NbStack-28]
+    limit           equ     dword ptr [esp+NbStack-32]
+    best_len        equ     dword ptr [esp+NbStack-36]
+    window          equ     dword ptr [esp+NbStack-40]
+    prev            equ     dword ptr [esp+NbStack-44]
+    scan_start      equ      word ptr [esp+NbStack-48]
+    wmask           equ     dword ptr [esp+NbStack-52]
+    match_start_ptr equ     dword ptr [esp+NbStack-56]
+    nice_match      equ     dword ptr [esp+NbStack-60]
+    scan            equ     dword ptr [esp+NbStack-64]
+
+    windowlen       equ     dword ptr [esp+NbStack-68]
+    match_start     equ     dword ptr [esp+NbStack-72]
+    strend          equ     dword ptr [esp+NbStack-76]
+    NbStackAdd      equ     (NbStack-24)
+
+    .386p
+
+    name    gvmatch
+    .MODEL  FLAT
+
+
+
+;  all the +zlib1222add offsets are due to the addition of fields
+;  in zlib in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
+;  (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
+;  if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
+
+    zlib1222add         equ     8
+
+;  Note : these value are good with a 8 bytes boundary pack structure
+    dep_chain_length    equ     74h+zlib1222add
+    dep_window          equ     30h+zlib1222add
+    dep_strstart        equ     64h+zlib1222add
+    dep_prev_length     equ     70h+zlib1222add
+    dep_nice_match      equ     88h+zlib1222add
+    dep_w_size          equ     24h+zlib1222add
+    dep_prev            equ     38h+zlib1222add
+    dep_w_mask          equ     2ch+zlib1222add
+    dep_good_match      equ     84h+zlib1222add
+    dep_match_start     equ     68h+zlib1222add
+    dep_lookahead       equ     6ch+zlib1222add
+
+
+_TEXT                   segment
+
+IFDEF NOUNDERLINE
+            public  longest_match
+            public  match_init
+ELSE
+            public  _longest_match
+            public  _match_init
+ENDIF
+
+    MAX_MATCH           equ     258
+    MIN_MATCH           equ     3
+    MIN_LOOKAHEAD       equ     (MAX_MATCH+MIN_MATCH+1)
+
+
+
+MAX_MATCH       equ     258
+MIN_MATCH       equ     3
+MIN_LOOKAHEAD   equ     (MAX_MATCH + MIN_MATCH + 1)
+MAX_MATCH_8_     equ     ((MAX_MATCH + 7) AND 0FFF0h)
+
+
+;;; stack frame offsets
+
+chainlenwmask   equ  esp + 0    ; high word: current chain len
+                    ; low word: s->wmask
+window      equ  esp + 4    ; local copy of s->window
+windowbestlen   equ  esp + 8    ; s->window + bestlen
+scanstart   equ  esp + 16   ; first two bytes of string
+scanend     equ  esp + 12   ; last two bytes of string
+scanalign   equ  esp + 20   ; dword-misalignment of string
+nicematch   equ  esp + 24   ; a good enough match size
+bestlen     equ  esp + 28   ; size of best match so far
+scan        equ  esp + 32   ; ptr to string wanting match
+
+LocalVarsSize   equ 36
+;   saved ebx   byte esp + 36
+;   saved edi   byte esp + 40
+;   saved esi   byte esp + 44
+;   saved ebp   byte esp + 48
+;   return address  byte esp + 52
+deflatestate    equ  esp + 56   ; the function arguments
+curmatch    equ  esp + 60
+
+;;; Offsets for fields in the deflate_state structure. These numbers
+;;; are calculated from the definition of deflate_state, with the
+;;; assumption that the compiler will dword-align the fields. (Thus,
+;;; changing the definition of deflate_state could easily cause this
+;;; program to crash horribly, without so much as a warning at
+;;; compile time. Sigh.)
+
+dsWSize     equ 36+zlib1222add
+dsWMask     equ 44+zlib1222add
+dsWindow    equ 48+zlib1222add
+dsPrev      equ 56+zlib1222add
+dsMatchLen  equ 88+zlib1222add
+dsPrevMatch equ 92+zlib1222add
+dsStrStart  equ 100+zlib1222add
+dsMatchStart    equ 104+zlib1222add
+dsLookahead equ 108+zlib1222add
+dsPrevLen   equ 112+zlib1222add
+dsMaxChainLen   equ 116+zlib1222add
+dsGoodMatch equ 132+zlib1222add
+dsNiceMatch equ 136+zlib1222add
+
+
+;;; match686.asm -- Pentium-Pro-optimized version of longest_match()
+;;; Written for zlib 1.1.2
+;;; Copyright (C) 1998 Brian Raiter <breadbox@muppetlabs.com>
+;;; You can look at http://www.muppetlabs.com/~breadbox/software/assembly.html
+;;;
+;;
+;;  This software is provided 'as-is', without any express or implied
+;;  warranty.  In no event will the authors be held liable for any damages
+;;  arising from the use of this software.
+;;
+;;  Permission is granted to anyone to use this software for any purpose,
+;;  including commercial applications, and to alter it and redistribute it
+;;  freely, subject to the following restrictions:
+;;
+;;  1. The origin of this software must not be misrepresented; you must not
+;;     claim that you wrote the original software. If you use this software
+;;     in a product, an acknowledgment in the product documentation would be
+;;     appreciated but is not required.
+;;  2. Altered source versions must be plainly marked as such, and must not be
+;;     misrepresented as being the original software
+;;  3. This notice may not be removed or altered from any source distribution.
+;;
+
+;GLOBAL _longest_match, _match_init
+
+
+;SECTION    .text
+
+;;; uInt longest_match(deflate_state *deflatestate, IPos curmatch)
+
+;_longest_match:
+    IFDEF NOUNDERLINE
+    longest_match       proc near
+    ELSE
+    _longest_match      proc near
+    ENDIF
+.FPO (9, 4, 0, 0, 1, 0)
+
+;;; Save registers that the compiler may be using, and adjust esp to
+;;; make room for our stack frame.
+
+        push    ebp
+        push    edi
+        push    esi
+        push    ebx
+        sub esp, LocalVarsSize
+
+;;; Retrieve the function arguments. ecx will hold cur_match
+;;; throughout the entire function. edx will hold the pointer to the
+;;; deflate_state structure during the function's setup (before
+;;; entering the main loop.
+
+        mov edx, [deflatestate]
+        mov ecx, [curmatch]
+
+;;; uInt wmask = s->w_mask;
+;;; unsigned chain_length = s->max_chain_length;
+;;; if (s->prev_length >= s->good_match) {
+;;;     chain_length >>= 2;
+;;; }
+
+        mov eax, [edx + dsPrevLen]
+        mov ebx, [edx + dsGoodMatch]
+        cmp eax, ebx
+        mov eax, [edx + dsWMask]
+        mov ebx, [edx + dsMaxChainLen]
+        jl  LastMatchGood
+        shr ebx, 2
+LastMatchGood:
+
+;;; chainlen is decremented once beforehand so that the function can
+;;; use the sign flag instead of the zero flag for the exit test.
+;;; It is then shifted into the high word, to make room for the wmask
+;;; value, which it will always accompany.
+
+        dec ebx
+        shl ebx, 16
+        or  ebx, eax
+        mov [chainlenwmask], ebx
+
+;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
+
+        mov eax, [edx + dsNiceMatch]
+        mov ebx, [edx + dsLookahead]
+        cmp ebx, eax
+        jl  LookaheadLess
+        mov ebx, eax
+LookaheadLess:  mov [nicematch], ebx
+
+;;; register Bytef *scan = s->window + s->strstart;
+
+        mov esi, [edx + dsWindow]
+        mov [window], esi
+        mov ebp, [edx + dsStrStart]
+        lea edi, [esi + ebp]
+        mov [scan], edi
+
+;;; Determine how many bytes the scan ptr is off from being
+;;; dword-aligned.
+
+        mov eax, edi
+        neg eax
+        and eax, 3
+        mov [scanalign], eax
+
+;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+;;;     s->strstart - (IPos)MAX_DIST(s) : NIL;
+
+        mov eax, [edx + dsWSize]
+        sub eax, MIN_LOOKAHEAD
+        sub ebp, eax
+        jg  LimitPositive
+        xor ebp, ebp
+LimitPositive:
+
+;;; int best_len = s->prev_length;
+
+        mov eax, [edx + dsPrevLen]
+        mov [bestlen], eax
+
+;;; Store the sum of s->window + best_len in esi locally, and in esi.
+
+        add esi, eax
+        mov [windowbestlen], esi
+
+;;; register ush scan_start = *(ushf*)scan;
+;;; register ush scan_end   = *(ushf*)(scan+best_len-1);
+;;; Posf *prev = s->prev;
+
+        movzx   ebx, word ptr [edi]
+        mov [scanstart], ebx
+        movzx   ebx, word ptr [edi + eax - 1]
+        mov [scanend], ebx
+        mov edi, [edx + dsPrev]
+
+;;; Jump into the main loop.
+
+        mov edx, [chainlenwmask]
+        jmp short LoopEntry
+
+align 4
+
+;;; do {
+;;;     match = s->window + cur_match;
+;;;     if (*(ushf*)(match+best_len-1) != scan_end ||
+;;;         *(ushf*)match != scan_start) continue;
+;;;     [...]
+;;; } while ((cur_match = prev[cur_match & wmask]) > limit
+;;;          && --chain_length != 0);
+;;;
+;;; Here is the inner loop of the function. The function will spend the
+;;; majority of its time in this loop, and majority of that time will
+;;; be spent in the first ten instructions.
+;;;
+;;; Within this loop:
+;;; ebx = scanend
+;;; ecx = curmatch
+;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
+;;; esi = windowbestlen - i.e., (window + bestlen)
+;;; edi = prev
+;;; ebp = limit
+
+LookupLoop:
+        and ecx, edx
+        movzx   ecx, word ptr [edi + ecx*2]
+        cmp ecx, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+LoopEntry:  movzx   eax, word ptr [esi + ecx - 1]
+        cmp eax, ebx
+        jnz LookupLoop
+        mov eax, [window]
+        movzx   eax, word ptr [eax + ecx]
+        cmp eax, [scanstart]
+        jnz LookupLoop
+
+;;; Store the current value of chainlen.
+
+        mov [chainlenwmask], edx
+
+;;; Point edi to the string under scrutiny, and esi to the string we
+;;; are hoping to match it up with. In actuality, esi and edi are
+;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
+;;; initialized to -(MAX_MATCH_8 - scanalign).
+
+        mov esi, [window]
+        mov edi, [scan]
+        add esi, ecx
+        mov eax, [scanalign]
+        mov edx, 0fffffef8h; -(MAX_MATCH_8)
+        lea edi, [edi + eax + 0108h] ;MAX_MATCH_8]
+        lea esi, [esi + eax + 0108h] ;MAX_MATCH_8]
+
+;;; Test the strings for equality, 8 bytes at a time. At the end,
+;;; adjust edx so that it is offset to the exact byte that mismatched.
+;;;
+;;; We already know at this point that the first three bytes of the
+;;; strings match each other, and they can be safely passed over before
+;;; starting the compare loop. So what this code does is skip over 0-3
+;;; bytes, as much as necessary in order to dword-align the edi
+;;; pointer. (esi will still be misaligned three times out of four.)
+;;;
+;;; It should be confessed that this loop usually does not represent
+;;; much of the total running time. Replacing it with a more
+;;; straightforward "rep cmpsb" would not drastically degrade
+;;; performance.
+
+LoopCmps:
+        mov eax, [esi + edx]
+        xor eax, [edi + edx]
+        jnz LeaveLoopCmps
+        mov eax, [esi + edx + 4]
+        xor eax, [edi + edx + 4]
+        jnz LeaveLoopCmps4
+        add edx, 8
+        jnz LoopCmps
+        jmp short LenMaximum
+LeaveLoopCmps4: add edx, 4
+LeaveLoopCmps:  test    eax, 0000FFFFh
+        jnz LenLower
+        add edx,  2
+        shr eax, 16
+LenLower:   sub al, 1
+        adc edx, 0
+
+;;; Calculate the length of the match. If it is longer than MAX_MATCH,
+;;; then automatically accept it as the best possible match and leave.
+
+        lea eax, [edi + edx]
+        mov edi, [scan]
+        sub eax, edi
+        cmp eax, MAX_MATCH
+        jge LenMaximum
+
+;;; If the length of the match is not longer than the best match we
+;;; have so far, then forget it and return to the lookup loop.
+
+        mov edx, [deflatestate]
+        mov ebx, [bestlen]
+        cmp eax, ebx
+        jg  LongerMatch
+        mov esi, [windowbestlen]
+        mov edi, [edx + dsPrev]
+        mov ebx, [scanend]
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;;         s->match_start = cur_match;
+;;;         best_len = len;
+;;;         if (len >= nice_match) break;
+;;;         scan_end = *(ushf*)(scan+best_len-1);
+
+LongerMatch:    mov ebx, [nicematch]
+        mov [bestlen], eax
+        mov [edx + dsMatchStart], ecx
+        cmp eax, ebx
+        jge LeaveNow
+        mov esi, [window]
+        add esi, eax
+        mov [windowbestlen], esi
+        movzx   ebx, word ptr [edi + eax - 1]
+        mov edi, [edx + dsPrev]
+        mov [scanend], ebx
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;; Accept the current string, with the maximum possible length.
+
+LenMaximum: mov edx, [deflatestate]
+        mov dword ptr [bestlen], MAX_MATCH
+        mov [edx + dsMatchStart], ecx
+
+;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+;;; return s->lookahead;
+
+LeaveNow:
+        mov edx, [deflatestate]
+        mov ebx, [bestlen]
+        mov eax, [edx + dsLookahead]
+        cmp ebx, eax
+        jg  LookaheadRet
+        mov eax, ebx
+LookaheadRet:
+
+;;; Restore the stack and return from whence we came.
+
+        add esp, LocalVarsSize
+        pop ebx
+        pop esi
+        pop edi
+        pop ebp
+
+        ret
+; please don't remove this string !
+; Your can freely use match686 in any free or commercial app if you don't remove the string in the binary!
+    db     0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998",0dh,0ah
+
+
+    IFDEF NOUNDERLINE
+    longest_match       endp
+    ELSE
+    _longest_match      endp
+    ENDIF
+
+    IFDEF NOUNDERLINE
+    match_init      proc near
+                    ret
+    match_init      endp
+    ELSE
+    _match_init     proc near
+                    ret
+    _match_init     endp
+    ENDIF
+
+
+_TEXT   ends
+end
diff --git a/xs/src/png/zlib/contrib/masmx86/readme.txt b/xs/src/png/zlib/contrib/masmx86/readme.txt
new file mode 100644
index 000000000..3f8888679
--- /dev/null
+++ b/xs/src/png/zlib/contrib/masmx86/readme.txt
@@ -0,0 +1,27 @@
+
+Summary
+-------
+This directory contains ASM implementations of the functions
+longest_match() and inflate_fast().
+
+
+Use instructions
+----------------
+Assemble using MASM, and copy the object files into the zlib source
+directory, then run the appropriate makefile, as suggested below.  You can
+donwload MASM from here:
+
+    http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=7a1c9da0-0510-44a2-b042-7ef370530c64
+
+You can also get objects files here:
+
+    http://www.winimage.com/zLibDll/zlib124_masm_obj.zip
+
+Build instructions
+------------------
+* With Microsoft C and MASM:
+nmake -f win32/Makefile.msc LOC="-DASMV -DASMINF" OBJA="match686.obj inffas32.obj"
+
+* With Borland C and TASM:
+make -f win32/Makefile.bor LOCAL_ZLIB="-DASMV -DASMINF" OBJA="match686.obj inffas32.obj" OBJPA="+match686c.obj+match686.obj+inffas32.obj"
+
diff --git a/xs/src/png/zlib/contrib/minizip/Makefile b/xs/src/png/zlib/contrib/minizip/Makefile
new file mode 100644
index 000000000..84eaad20d
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/Makefile
@@ -0,0 +1,25 @@
+CC=cc
+CFLAGS=-O -I../..
+
+UNZ_OBJS = miniunz.o unzip.o ioapi.o ../../libz.a
+ZIP_OBJS = minizip.o zip.o   ioapi.o ../../libz.a
+
+.c.o:
+	$(CC) -c $(CFLAGS) $*.c
+
+all: miniunz minizip
+
+miniunz:  $(UNZ_OBJS)
+	$(CC) $(CFLAGS) -o $@ $(UNZ_OBJS)
+
+minizip:  $(ZIP_OBJS)
+	$(CC) $(CFLAGS) -o $@ $(ZIP_OBJS)
+
+test:	miniunz minizip
+	./minizip test readme.txt
+	./miniunz -l test.zip
+	mv readme.txt readme.old
+	./miniunz test.zip
+
+clean:
+	/bin/rm -f *.o *~ minizip miniunz
diff --git a/xs/src/png/zlib/contrib/minizip/Makefile.am b/xs/src/png/zlib/contrib/minizip/Makefile.am
new file mode 100644
index 000000000..d343011eb
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/Makefile.am
@@ -0,0 +1,45 @@
+lib_LTLIBRARIES = libminizip.la
+
+if COND_DEMOS
+bin_PROGRAMS = miniunzip minizip
+endif
+
+zlib_top_srcdir = $(top_srcdir)/../..
+zlib_top_builddir = $(top_builddir)/../..
+
+AM_CPPFLAGS = -I$(zlib_top_srcdir)
+AM_LDFLAGS = -L$(zlib_top_builddir)
+
+if WIN32
+iowin32_src = iowin32.c
+iowin32_h = iowin32.h
+endif
+
+libminizip_la_SOURCES = \
+	ioapi.c \
+	mztools.c \
+	unzip.c \
+	zip.c \
+	${iowin32_src}
+
+libminizip_la_LDFLAGS = $(AM_LDFLAGS) -version-info 1:0:0 -lz
+
+minizip_includedir = $(includedir)/minizip
+minizip_include_HEADERS = \
+	crypt.h \
+	ioapi.h \
+	mztools.h \
+	unzip.h \
+	zip.h \
+	${iowin32_h}
+
+pkgconfigdir = $(libdir)/pkgconfig
+pkgconfig_DATA = minizip.pc
+
+EXTRA_PROGRAMS = miniunzip minizip
+
+miniunzip_SOURCES = miniunz.c
+miniunzip_LDADD = libminizip.la
+
+minizip_SOURCES = minizip.c
+minizip_LDADD = libminizip.la -lz
diff --git a/xs/src/png/zlib/contrib/minizip/MiniZip64_Changes.txt b/xs/src/png/zlib/contrib/minizip/MiniZip64_Changes.txt
new file mode 100644
index 000000000..13a1bd91a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/MiniZip64_Changes.txt
@@ -0,0 +1,6 @@
+
+MiniZip 1.1 was derrived from MiniZip at version 1.01f
+
+Change in 1.0 (Okt 2009)
+ - **TODO - Add history**
+
diff --git a/xs/src/png/zlib/contrib/minizip/MiniZip64_info.txt b/xs/src/png/zlib/contrib/minizip/MiniZip64_info.txt
new file mode 100644
index 000000000..57d715242
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/MiniZip64_info.txt
@@ -0,0 +1,74 @@
+MiniZip - Copyright (c) 1998-2010 - by Gilles Vollant - version 1.1 64 bits from Mathias Svensson
+
+Introduction
+---------------------
+MiniZip 1.1 is built from MiniZip 1.0 by Gilles Vollant ( http://www.winimage.com/zLibDll/minizip.html )
+
+When adding ZIP64 support into minizip it would result into risk of breaking compatibility with minizip 1.0.
+All possible work was done for compatibility.
+
+
+Background
+---------------------
+When adding ZIP64 support Mathias Svensson found that Even Rouault have added ZIP64 
+support for unzip.c into minizip for a open source project called gdal ( http://www.gdal.org/ )
+
+That was used as a starting point. And after that ZIP64 support was added to zip.c
+some refactoring and code cleanup was also done.
+
+
+Changed from MiniZip 1.0 to MiniZip 1.1
+---------------------------------------
+* Added ZIP64 support for unzip ( by Even Rouault )
+* Added ZIP64 support for zip ( by Mathias Svensson )
+* Reverted some changed that Even Rouault did.
+* Bunch of patches received from Gulles Vollant that he received for MiniZip from various users.
+* Added unzip patch for BZIP Compression method (patch create by Daniel Borca)
+* Added BZIP Compress method for zip
+* Did some refactoring and code cleanup
+
+
+Credits
+
+ Gilles Vollant    - Original MiniZip author
+ Even Rouault      - ZIP64 unzip Support
+ Daniel Borca      - BZip Compression method support in unzip
+ Mathias Svensson  - ZIP64 zip support
+ Mathias Svensson  - BZip Compression method support in zip
+
+ Resources
+
+ ZipLayout   http://result42.com/projects/ZipFileLayout
+             Command line tool for Windows that shows the layout and information of the headers in a zip archive.
+             Used when debugging and validating the creation of zip files using MiniZip64
+
+
+ ZIP App Note  http://www.pkware.com/documents/casestudies/APPNOTE.TXT
+               Zip File specification
+
+
+Notes.
+ * To be able to use BZip compression method in zip64.c or unzip64.c the BZIP2 lib is needed and HAVE_BZIP2 need to be defined.
+
+License
+----------------------------------------------------------
+   Condition of use and distribution are the same than zlib :
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+----------------------------------------------------------
+
diff --git a/xs/src/png/zlib/contrib/minizip/configure.ac b/xs/src/png/zlib/contrib/minizip/configure.ac
new file mode 100644
index 000000000..5b1197097
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/configure.ac
@@ -0,0 +1,32 @@
+#                                               -*- Autoconf -*-
+# Process this file with autoconf to produce a configure script.
+
+AC_INIT([minizip], [1.2.11], [bugzilla.redhat.com])
+AC_CONFIG_SRCDIR([minizip.c])
+AM_INIT_AUTOMAKE([foreign])
+LT_INIT
+
+AC_MSG_CHECKING([whether to build example programs])
+AC_ARG_ENABLE([demos], AC_HELP_STRING([--enable-demos], [build example programs]))
+AM_CONDITIONAL([COND_DEMOS], [test "$enable_demos" = yes])
+if test "$enable_demos" = yes
+then
+	AC_MSG_RESULT([yes])
+else
+	AC_MSG_RESULT([no])
+fi
+
+case "${host}" in
+	*-mingw* | mingw*)
+		WIN32="yes"
+		;;
+	*)
+		;;
+esac
+AM_CONDITIONAL([WIN32], [test "${WIN32}" = "yes"])
+
+
+AC_SUBST([HAVE_UNISTD_H], [0])
+AC_CHECK_HEADER([unistd.h], [HAVE_UNISTD_H=1], [])
+AC_CONFIG_FILES([Makefile minizip.pc])
+AC_OUTPUT
diff --git a/xs/src/png/zlib/contrib/minizip/crypt.h b/xs/src/png/zlib/contrib/minizip/crypt.h
new file mode 100644
index 000000000..1e9e8200b
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/crypt.h
@@ -0,0 +1,131 @@
+/* crypt.h -- base code for crypt/uncrypt ZIPfile
+
+
+   Version 1.01e, February 12th, 2005
+
+   Copyright (C) 1998-2005 Gilles Vollant
+
+   This code is a modified version of crypting code in Infozip distribution
+
+   The encryption/decryption parts of this source code (as opposed to the
+   non-echoing password parts) were originally written in Europe.  The
+   whole source package can be freely distributed, including from the USA.
+   (Prior to January 2000, re-export from the US was a violation of US law.)
+
+   This encryption code is a direct transcription of the algorithm from
+   Roger Schlafly, described by Phil Katz in the file appnote.txt.  This
+   file (appnote.txt) is distributed with the PKZIP program (even in the
+   version without encryption capabilities).
+
+   If you don't need crypting in your application, just define symbols
+   NOCRYPT and NOUNCRYPT.
+
+   This code support the "Traditional PKWARE Encryption".
+
+   The new AES encryption added on Zip format by Winzip (see the page
+   http://www.winzip.com/aes_info.htm ) and PKWare PKZip 5.x Strong
+   Encryption is not supported.
+*/
+
+#define CRC32(c, b) ((*(pcrc_32_tab+(((int)(c) ^ (b)) & 0xff))) ^ ((c) >> 8))
+
+/***********************************************************************
+ * Return the next byte in the pseudo-random sequence
+ */
+static int decrypt_byte(unsigned long* pkeys, const z_crc_t* pcrc_32_tab)
+{
+    unsigned temp;  /* POTENTIAL BUG:  temp*(temp^1) may overflow in an
+                     * unpredictable manner on 16-bit systems; not a problem
+                     * with any known compiler so far, though */
+
+    temp = ((unsigned)(*(pkeys+2)) & 0xffff) | 2;
+    return (int)(((temp * (temp ^ 1)) >> 8) & 0xff);
+}
+
+/***********************************************************************
+ * Update the encryption keys with the next byte of plain text
+ */
+static int update_keys(unsigned long* pkeys,const z_crc_t* pcrc_32_tab,int c)
+{
+    (*(pkeys+0)) = CRC32((*(pkeys+0)), c);
+    (*(pkeys+1)) += (*(pkeys+0)) & 0xff;
+    (*(pkeys+1)) = (*(pkeys+1)) * 134775813L + 1;
+    {
+      register int keyshift = (int)((*(pkeys+1)) >> 24);
+      (*(pkeys+2)) = CRC32((*(pkeys+2)), keyshift);
+    }
+    return c;
+}
+
+
+/***********************************************************************
+ * Initialize the encryption keys and the random header according to
+ * the given password.
+ */
+static void init_keys(const char* passwd,unsigned long* pkeys,const z_crc_t* pcrc_32_tab)
+{
+    *(pkeys+0) = 305419896L;
+    *(pkeys+1) = 591751049L;
+    *(pkeys+2) = 878082192L;
+    while (*passwd != '\0') {
+        update_keys(pkeys,pcrc_32_tab,(int)*passwd);
+        passwd++;
+    }
+}
+
+#define zdecode(pkeys,pcrc_32_tab,c) \
+    (update_keys(pkeys,pcrc_32_tab,c ^= decrypt_byte(pkeys,pcrc_32_tab)))
+
+#define zencode(pkeys,pcrc_32_tab,c,t) \
+    (t=decrypt_byte(pkeys,pcrc_32_tab), update_keys(pkeys,pcrc_32_tab,c), t^(c))
+
+#ifdef INCLUDECRYPTINGCODE_IFCRYPTALLOWED
+
+#define RAND_HEAD_LEN  12
+   /* "last resort" source for second part of crypt seed pattern */
+#  ifndef ZCR_SEED2
+#    define ZCR_SEED2 3141592654UL     /* use PI as default pattern */
+#  endif
+
+static int crypthead(const char* passwd,      /* password string */
+                     unsigned char* buf,      /* where to write header */
+                     int bufSize,
+                     unsigned long* pkeys,
+                     const z_crc_t* pcrc_32_tab,
+                     unsigned long crcForCrypting)
+{
+    int n;                       /* index in random header */
+    int t;                       /* temporary */
+    int c;                       /* random byte */
+    unsigned char header[RAND_HEAD_LEN-2]; /* random header */
+    static unsigned calls = 0;   /* ensure different random header each time */
+
+    if (bufSize<RAND_HEAD_LEN)
+      return 0;
+
+    /* First generate RAND_HEAD_LEN-2 random bytes. We encrypt the
+     * output of rand() to get less predictability, since rand() is
+     * often poorly implemented.
+     */
+    if (++calls == 1)
+    {
+        srand((unsigned)(time(NULL) ^ ZCR_SEED2));
+    }
+    init_keys(passwd, pkeys, pcrc_32_tab);
+    for (n = 0; n < RAND_HEAD_LEN-2; n++)
+    {
+        c = (rand() >> 7) & 0xff;
+        header[n] = (unsigned char)zencode(pkeys, pcrc_32_tab, c, t);
+    }
+    /* Encrypt random header (last two bytes is high word of crc) */
+    init_keys(passwd, pkeys, pcrc_32_tab);
+    for (n = 0; n < RAND_HEAD_LEN-2; n++)
+    {
+        buf[n] = (unsigned char)zencode(pkeys, pcrc_32_tab, header[n], t);
+    }
+    buf[n++] = (unsigned char)zencode(pkeys, pcrc_32_tab, (int)(crcForCrypting >> 16) & 0xff, t);
+    buf[n++] = (unsigned char)zencode(pkeys, pcrc_32_tab, (int)(crcForCrypting >> 24) & 0xff, t);
+    return n;
+}
+
+#endif
diff --git a/xs/src/png/zlib/contrib/minizip/ioapi.c b/xs/src/png/zlib/contrib/minizip/ioapi.c
new file mode 100644
index 000000000..7f5c191b2
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/ioapi.c
@@ -0,0 +1,247 @@
+/* ioapi.h -- IO base function header for compress/uncompress .zip
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+*/
+
+#if defined(_WIN32) && (!(defined(_CRT_SECURE_NO_WARNINGS)))
+        #define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#if defined(__APPLE__) || defined(IOAPI_NO_64)
+// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
+#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
+#define FTELLO_FUNC(stream) ftello(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
+#else
+#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
+#define FTELLO_FUNC(stream) ftello64(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
+#endif
+
+
+#include "ioapi.h"
+
+voidpf call_zopen64 (const zlib_filefunc64_32_def* pfilefunc,const void*filename,int mode)
+{
+    if (pfilefunc->zfile_func64.zopen64_file != NULL)
+        return (*(pfilefunc->zfile_func64.zopen64_file)) (pfilefunc->zfile_func64.opaque,filename,mode);
+    else
+    {
+        return (*(pfilefunc->zopen32_file))(pfilefunc->zfile_func64.opaque,(const char*)filename,mode);
+    }
+}
+
+long call_zseek64 (const zlib_filefunc64_32_def* pfilefunc,voidpf filestream, ZPOS64_T offset, int origin)
+{
+    if (pfilefunc->zfile_func64.zseek64_file != NULL)
+        return (*(pfilefunc->zfile_func64.zseek64_file)) (pfilefunc->zfile_func64.opaque,filestream,offset,origin);
+    else
+    {
+        uLong offsetTruncated = (uLong)offset;
+        if (offsetTruncated != offset)
+            return -1;
+        else
+            return (*(pfilefunc->zseek32_file))(pfilefunc->zfile_func64.opaque,filestream,offsetTruncated,origin);
+    }
+}
+
+ZPOS64_T call_ztell64 (const zlib_filefunc64_32_def* pfilefunc,voidpf filestream)
+{
+    if (pfilefunc->zfile_func64.zseek64_file != NULL)
+        return (*(pfilefunc->zfile_func64.ztell64_file)) (pfilefunc->zfile_func64.opaque,filestream);
+    else
+    {
+        uLong tell_uLong = (*(pfilefunc->ztell32_file))(pfilefunc->zfile_func64.opaque,filestream);
+        if ((tell_uLong) == MAXU32)
+            return (ZPOS64_T)-1;
+        else
+            return tell_uLong;
+    }
+}
+
+void fill_zlib_filefunc64_32_def_from_filefunc32(zlib_filefunc64_32_def* p_filefunc64_32,const zlib_filefunc_def* p_filefunc32)
+{
+    p_filefunc64_32->zfile_func64.zopen64_file = NULL;
+    p_filefunc64_32->zopen32_file = p_filefunc32->zopen_file;
+    p_filefunc64_32->zfile_func64.zerror_file = p_filefunc32->zerror_file;
+    p_filefunc64_32->zfile_func64.zread_file = p_filefunc32->zread_file;
+    p_filefunc64_32->zfile_func64.zwrite_file = p_filefunc32->zwrite_file;
+    p_filefunc64_32->zfile_func64.ztell64_file = NULL;
+    p_filefunc64_32->zfile_func64.zseek64_file = NULL;
+    p_filefunc64_32->zfile_func64.zclose_file = p_filefunc32->zclose_file;
+    p_filefunc64_32->zfile_func64.zerror_file = p_filefunc32->zerror_file;
+    p_filefunc64_32->zfile_func64.opaque = p_filefunc32->opaque;
+    p_filefunc64_32->zseek32_file = p_filefunc32->zseek_file;
+    p_filefunc64_32->ztell32_file = p_filefunc32->ztell_file;
+}
+
+
+
+static voidpf  ZCALLBACK fopen_file_func OF((voidpf opaque, const char* filename, int mode));
+static uLong   ZCALLBACK fread_file_func OF((voidpf opaque, voidpf stream, void* buf, uLong size));
+static uLong   ZCALLBACK fwrite_file_func OF((voidpf opaque, voidpf stream, const void* buf,uLong size));
+static ZPOS64_T ZCALLBACK ftell64_file_func OF((voidpf opaque, voidpf stream));
+static long    ZCALLBACK fseek64_file_func OF((voidpf opaque, voidpf stream, ZPOS64_T offset, int origin));
+static int     ZCALLBACK fclose_file_func OF((voidpf opaque, voidpf stream));
+static int     ZCALLBACK ferror_file_func OF((voidpf opaque, voidpf stream));
+
+static voidpf ZCALLBACK fopen_file_func (voidpf opaque, const char* filename, int mode)
+{
+    FILE* file = NULL;
+    const char* mode_fopen = NULL;
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
+        mode_fopen = "rb";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+        mode_fopen = "r+b";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+        mode_fopen = "wb";
+
+    if ((filename!=NULL) && (mode_fopen != NULL))
+        file = fopen(filename, mode_fopen);
+    return file;
+}
+
+static voidpf ZCALLBACK fopen64_file_func (voidpf opaque, const void* filename, int mode)
+{
+    FILE* file = NULL;
+    const char* mode_fopen = NULL;
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
+        mode_fopen = "rb";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+        mode_fopen = "r+b";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+        mode_fopen = "wb";
+
+    if ((filename!=NULL) && (mode_fopen != NULL))
+        file = FOPEN_FUNC((const char*)filename, mode_fopen);
+    return file;
+}
+
+
+static uLong ZCALLBACK fread_file_func (voidpf opaque, voidpf stream, void* buf, uLong size)
+{
+    uLong ret;
+    ret = (uLong)fread(buf, 1, (size_t)size, (FILE *)stream);
+    return ret;
+}
+
+static uLong ZCALLBACK fwrite_file_func (voidpf opaque, voidpf stream, const void* buf, uLong size)
+{
+    uLong ret;
+    ret = (uLong)fwrite(buf, 1, (size_t)size, (FILE *)stream);
+    return ret;
+}
+
+static long ZCALLBACK ftell_file_func (voidpf opaque, voidpf stream)
+{
+    long ret;
+    ret = ftell((FILE *)stream);
+    return ret;
+}
+
+
+static ZPOS64_T ZCALLBACK ftell64_file_func (voidpf opaque, voidpf stream)
+{
+    ZPOS64_T ret;
+    ret = FTELLO_FUNC((FILE *)stream);
+    return ret;
+}
+
+static long ZCALLBACK fseek_file_func (voidpf  opaque, voidpf stream, uLong offset, int origin)
+{
+    int fseek_origin=0;
+    long ret;
+    switch (origin)
+    {
+    case ZLIB_FILEFUNC_SEEK_CUR :
+        fseek_origin = SEEK_CUR;
+        break;
+    case ZLIB_FILEFUNC_SEEK_END :
+        fseek_origin = SEEK_END;
+        break;
+    case ZLIB_FILEFUNC_SEEK_SET :
+        fseek_origin = SEEK_SET;
+        break;
+    default: return -1;
+    }
+    ret = 0;
+    if (fseek((FILE *)stream, offset, fseek_origin) != 0)
+        ret = -1;
+    return ret;
+}
+
+static long ZCALLBACK fseek64_file_func (voidpf  opaque, voidpf stream, ZPOS64_T offset, int origin)
+{
+    int fseek_origin=0;
+    long ret;
+    switch (origin)
+    {
+    case ZLIB_FILEFUNC_SEEK_CUR :
+        fseek_origin = SEEK_CUR;
+        break;
+    case ZLIB_FILEFUNC_SEEK_END :
+        fseek_origin = SEEK_END;
+        break;
+    case ZLIB_FILEFUNC_SEEK_SET :
+        fseek_origin = SEEK_SET;
+        break;
+    default: return -1;
+    }
+    ret = 0;
+
+    if(FSEEKO_FUNC((FILE *)stream, offset, fseek_origin) != 0)
+                        ret = -1;
+
+    return ret;
+}
+
+
+static int ZCALLBACK fclose_file_func (voidpf opaque, voidpf stream)
+{
+    int ret;
+    ret = fclose((FILE *)stream);
+    return ret;
+}
+
+static int ZCALLBACK ferror_file_func (voidpf opaque, voidpf stream)
+{
+    int ret;
+    ret = ferror((FILE *)stream);
+    return ret;
+}
+
+void fill_fopen_filefunc (pzlib_filefunc_def)
+  zlib_filefunc_def* pzlib_filefunc_def;
+{
+    pzlib_filefunc_def->zopen_file = fopen_file_func;
+    pzlib_filefunc_def->zread_file = fread_file_func;
+    pzlib_filefunc_def->zwrite_file = fwrite_file_func;
+    pzlib_filefunc_def->ztell_file = ftell_file_func;
+    pzlib_filefunc_def->zseek_file = fseek_file_func;
+    pzlib_filefunc_def->zclose_file = fclose_file_func;
+    pzlib_filefunc_def->zerror_file = ferror_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+void fill_fopen64_filefunc (zlib_filefunc64_def*  pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = fopen64_file_func;
+    pzlib_filefunc_def->zread_file = fread_file_func;
+    pzlib_filefunc_def->zwrite_file = fwrite_file_func;
+    pzlib_filefunc_def->ztell64_file = ftell64_file_func;
+    pzlib_filefunc_def->zseek64_file = fseek64_file_func;
+    pzlib_filefunc_def->zclose_file = fclose_file_func;
+    pzlib_filefunc_def->zerror_file = ferror_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
diff --git a/xs/src/png/zlib/contrib/minizip/ioapi.h b/xs/src/png/zlib/contrib/minizip/ioapi.h
new file mode 100644
index 000000000..8dcbdb06e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/ioapi.h
@@ -0,0 +1,208 @@
+/* ioapi.h -- IO base function header for compress/uncompress .zip
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         Changes
+
+    Oct-2009 - Defined ZPOS64_T to fpos_t on windows and u_int64_t on linux. (might need to find a better why for this)
+    Oct-2009 - Change to fseeko64, ftello64 and fopen64 so large files would work on linux.
+               More if/def section may be needed to support other platforms
+    Oct-2009 - Defined fxxxx64 calls to normal fopen/ftell/fseek so they would compile on windows.
+                          (but you should use iowin32.c for windows instead)
+
+*/
+
+#ifndef _ZLIBIOAPI64_H
+#define _ZLIBIOAPI64_H
+
+#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
+
+  // Linux needs this to support file operation on files larger then 4+GB
+  // But might need better if/def to select just the platforms that needs them.
+
+        #ifndef __USE_FILE_OFFSET64
+                #define __USE_FILE_OFFSET64
+        #endif
+        #ifndef __USE_LARGEFILE64
+                #define __USE_LARGEFILE64
+        #endif
+        #ifndef _LARGEFILE64_SOURCE
+                #define _LARGEFILE64_SOURCE
+        #endif
+        #ifndef _FILE_OFFSET_BIT
+                #define _FILE_OFFSET_BIT 64
+        #endif
+
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "zlib.h"
+
+#if defined(USE_FILE32API)
+#define fopen64 fopen
+#define ftello64 ftell
+#define fseeko64 fseek
+#else
+#ifdef __FreeBSD__
+#define fopen64 fopen
+#define ftello64 ftello
+#define fseeko64 fseeko
+#endif
+#ifdef _MSC_VER
+ #define fopen64 fopen
+ #if (_MSC_VER >= 1400) && (!(defined(NO_MSCVER_FILE64_FUNC)))
+  #define ftello64 _ftelli64
+  #define fseeko64 _fseeki64
+ #else // old MSC
+  #define ftello64 ftell
+  #define fseeko64 fseek
+ #endif
+#endif
+#endif
+
+/*
+#ifndef ZPOS64_T
+  #ifdef _WIN32
+                #define ZPOS64_T fpos_t
+  #else
+    #include <stdint.h>
+    #define ZPOS64_T uint64_t
+  #endif
+#endif
+*/
+
+#ifdef HAVE_MINIZIP64_CONF_H
+#include "mz64conf.h"
+#endif
+
+/* a type choosen by DEFINE */
+#ifdef HAVE_64BIT_INT_CUSTOM
+typedef  64BIT_INT_CUSTOM_TYPE ZPOS64_T;
+#else
+#ifdef HAS_STDINT_H
+#include "stdint.h"
+typedef uint64_t ZPOS64_T;
+#else
+
+/* Maximum unsigned 32-bit value used as placeholder for zip64 */
+#define MAXU32 0xffffffff
+
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+typedef unsigned __int64 ZPOS64_T;
+#else
+typedef unsigned long long int ZPOS64_T;
+#endif
+#endif
+#endif
+
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+#define ZLIB_FILEFUNC_SEEK_CUR (1)
+#define ZLIB_FILEFUNC_SEEK_END (2)
+#define ZLIB_FILEFUNC_SEEK_SET (0)
+
+#define ZLIB_FILEFUNC_MODE_READ      (1)
+#define ZLIB_FILEFUNC_MODE_WRITE     (2)
+#define ZLIB_FILEFUNC_MODE_READWRITEFILTER (3)
+
+#define ZLIB_FILEFUNC_MODE_EXISTING (4)
+#define ZLIB_FILEFUNC_MODE_CREATE   (8)
+
+
+#ifndef ZCALLBACK
+ #if (defined(WIN32) || defined(_WIN32) || defined (WINDOWS) || defined (_WINDOWS)) && defined(CALLBACK) && defined (USEWINDOWS_CALLBACK)
+   #define ZCALLBACK CALLBACK
+ #else
+   #define ZCALLBACK
+ #endif
+#endif
+
+
+
+
+typedef voidpf   (ZCALLBACK *open_file_func)      OF((voidpf opaque, const char* filename, int mode));
+typedef uLong    (ZCALLBACK *read_file_func)      OF((voidpf opaque, voidpf stream, void* buf, uLong size));
+typedef uLong    (ZCALLBACK *write_file_func)     OF((voidpf opaque, voidpf stream, const void* buf, uLong size));
+typedef int      (ZCALLBACK *close_file_func)     OF((voidpf opaque, voidpf stream));
+typedef int      (ZCALLBACK *testerror_file_func) OF((voidpf opaque, voidpf stream));
+
+typedef long     (ZCALLBACK *tell_file_func)      OF((voidpf opaque, voidpf stream));
+typedef long     (ZCALLBACK *seek_file_func)      OF((voidpf opaque, voidpf stream, uLong offset, int origin));
+
+
+/* here is the "old" 32 bits structure structure */
+typedef struct zlib_filefunc_def_s
+{
+    open_file_func      zopen_file;
+    read_file_func      zread_file;
+    write_file_func     zwrite_file;
+    tell_file_func      ztell_file;
+    seek_file_func      zseek_file;
+    close_file_func     zclose_file;
+    testerror_file_func zerror_file;
+    voidpf              opaque;
+} zlib_filefunc_def;
+
+typedef ZPOS64_T (ZCALLBACK *tell64_file_func)    OF((voidpf opaque, voidpf stream));
+typedef long     (ZCALLBACK *seek64_file_func)    OF((voidpf opaque, voidpf stream, ZPOS64_T offset, int origin));
+typedef voidpf   (ZCALLBACK *open64_file_func)    OF((voidpf opaque, const void* filename, int mode));
+
+typedef struct zlib_filefunc64_def_s
+{
+    open64_file_func    zopen64_file;
+    read_file_func      zread_file;
+    write_file_func     zwrite_file;
+    tell64_file_func    ztell64_file;
+    seek64_file_func    zseek64_file;
+    close_file_func     zclose_file;
+    testerror_file_func zerror_file;
+    voidpf              opaque;
+} zlib_filefunc64_def;
+
+void fill_fopen64_filefunc OF((zlib_filefunc64_def* pzlib_filefunc_def));
+void fill_fopen_filefunc OF((zlib_filefunc_def* pzlib_filefunc_def));
+
+/* now internal definition, only for zip.c and unzip.h */
+typedef struct zlib_filefunc64_32_def_s
+{
+    zlib_filefunc64_def zfile_func64;
+    open_file_func      zopen32_file;
+    tell_file_func      ztell32_file;
+    seek_file_func      zseek32_file;
+} zlib_filefunc64_32_def;
+
+
+#define ZREAD64(filefunc,filestream,buf,size)     ((*((filefunc).zfile_func64.zread_file))   ((filefunc).zfile_func64.opaque,filestream,buf,size))
+#define ZWRITE64(filefunc,filestream,buf,size)    ((*((filefunc).zfile_func64.zwrite_file))  ((filefunc).zfile_func64.opaque,filestream,buf,size))
+//#define ZTELL64(filefunc,filestream)            ((*((filefunc).ztell64_file)) ((filefunc).opaque,filestream))
+//#define ZSEEK64(filefunc,filestream,pos,mode)   ((*((filefunc).zseek64_file)) ((filefunc).opaque,filestream,pos,mode))
+#define ZCLOSE64(filefunc,filestream)             ((*((filefunc).zfile_func64.zclose_file))  ((filefunc).zfile_func64.opaque,filestream))
+#define ZERROR64(filefunc,filestream)             ((*((filefunc).zfile_func64.zerror_file))  ((filefunc).zfile_func64.opaque,filestream))
+
+voidpf call_zopen64 OF((const zlib_filefunc64_32_def* pfilefunc,const void*filename,int mode));
+long    call_zseek64 OF((const zlib_filefunc64_32_def* pfilefunc,voidpf filestream, ZPOS64_T offset, int origin));
+ZPOS64_T call_ztell64 OF((const zlib_filefunc64_32_def* pfilefunc,voidpf filestream));
+
+void    fill_zlib_filefunc64_32_def_from_filefunc32(zlib_filefunc64_32_def* p_filefunc64_32,const zlib_filefunc_def* p_filefunc32);
+
+#define ZOPEN64(filefunc,filename,mode)         (call_zopen64((&(filefunc)),(filename),(mode)))
+#define ZTELL64(filefunc,filestream)            (call_ztell64((&(filefunc)),(filestream)))
+#define ZSEEK64(filefunc,filestream,pos,mode)   (call_zseek64((&(filefunc)),(filestream),(pos),(mode)))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/xs/src/png/zlib/contrib/minizip/iowin32.c b/xs/src/png/zlib/contrib/minizip/iowin32.c
new file mode 100644
index 000000000..274f39eb1
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/iowin32.c
@@ -0,0 +1,462 @@
+/* iowin32.c -- IO base function header for compress/uncompress .zip
+     Version 1.1, February 14h, 2010
+     part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+     For more info read MiniZip_info.txt
+
+*/
+
+#include <stdlib.h>
+
+#include "zlib.h"
+#include "ioapi.h"
+#include "iowin32.h"
+
+#ifndef INVALID_HANDLE_VALUE
+#define INVALID_HANDLE_VALUE (0xFFFFFFFF)
+#endif
+
+#ifndef INVALID_SET_FILE_POINTER
+#define INVALID_SET_FILE_POINTER ((DWORD)-1)
+#endif
+
+
+// see Include/shared/winapifamily.h in the Windows Kit
+#if defined(WINAPI_FAMILY_PARTITION) && (!(defined(IOWIN32_USING_WINRT_API)))
+#if WINAPI_FAMILY_ONE_PARTITION(WINAPI_FAMILY, WINAPI_PARTITION_APP)
+#define IOWIN32_USING_WINRT_API 1
+#endif
+#endif
+
+voidpf  ZCALLBACK win32_open_file_func  OF((voidpf opaque, const char* filename, int mode));
+uLong   ZCALLBACK win32_read_file_func  OF((voidpf opaque, voidpf stream, void* buf, uLong size));
+uLong   ZCALLBACK win32_write_file_func OF((voidpf opaque, voidpf stream, const void* buf, uLong size));
+ZPOS64_T ZCALLBACK win32_tell64_file_func  OF((voidpf opaque, voidpf stream));
+long    ZCALLBACK win32_seek64_file_func  OF((voidpf opaque, voidpf stream, ZPOS64_T offset, int origin));
+int     ZCALLBACK win32_close_file_func OF((voidpf opaque, voidpf stream));
+int     ZCALLBACK win32_error_file_func OF((voidpf opaque, voidpf stream));
+
+typedef struct
+{
+    HANDLE hf;
+    int error;
+} WIN32FILE_IOWIN;
+
+
+static void win32_translate_open_mode(int mode,
+                                      DWORD* lpdwDesiredAccess,
+                                      DWORD* lpdwCreationDisposition,
+                                      DWORD* lpdwShareMode,
+                                      DWORD* lpdwFlagsAndAttributes)
+{
+    *lpdwDesiredAccess = *lpdwShareMode = *lpdwFlagsAndAttributes = *lpdwCreationDisposition = 0;
+
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
+    {
+        *lpdwDesiredAccess = GENERIC_READ;
+        *lpdwCreationDisposition = OPEN_EXISTING;
+        *lpdwShareMode = FILE_SHARE_READ;
+    }
+    else if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+    {
+        *lpdwDesiredAccess = GENERIC_WRITE | GENERIC_READ;
+        *lpdwCreationDisposition = OPEN_EXISTING;
+    }
+    else if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+    {
+        *lpdwDesiredAccess = GENERIC_WRITE | GENERIC_READ;
+        *lpdwCreationDisposition = CREATE_ALWAYS;
+    }
+}
+
+static voidpf win32_build_iowin(HANDLE hFile)
+{
+    voidpf ret=NULL;
+
+    if ((hFile != NULL) && (hFile != INVALID_HANDLE_VALUE))
+    {
+        WIN32FILE_IOWIN w32fiow;
+        w32fiow.hf = hFile;
+        w32fiow.error = 0;
+        ret = malloc(sizeof(WIN32FILE_IOWIN));
+
+        if (ret==NULL)
+            CloseHandle(hFile);
+        else
+            *((WIN32FILE_IOWIN*)ret) = w32fiow;
+    }
+    return ret;
+}
+
+voidpf ZCALLBACK win32_open64_file_func (voidpf opaque,const void* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+#ifdef UNICODE
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile2((LPCTSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+    {
+        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
+        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
+        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+    }
+#endif
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile((LPCTSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+voidpf ZCALLBACK win32_open64_file_funcA (voidpf opaque,const void* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+    {
+        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
+        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
+        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+    }
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFileA((LPCSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+voidpf ZCALLBACK win32_open64_file_funcW (voidpf opaque,const void* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile2((LPCWSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition,NULL);
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFileW((LPCWSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+voidpf ZCALLBACK win32_open_file_func (voidpf opaque,const char* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+#ifdef UNICODE
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile2((LPCTSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+    {
+        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
+        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
+        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+    }
+#endif
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile((LPCTSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+uLong ZCALLBACK win32_read_file_func (voidpf opaque, voidpf stream, void* buf,uLong size)
+{
+    uLong ret=0;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+
+    if (hFile != NULL)
+    {
+        if (!ReadFile(hFile, buf, size, &ret, NULL))
+        {
+            DWORD dwErr = GetLastError();
+            if (dwErr == ERROR_HANDLE_EOF)
+                dwErr = 0;
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+        }
+    }
+
+    return ret;
+}
+
+
+uLong ZCALLBACK win32_write_file_func (voidpf opaque,voidpf stream,const void* buf,uLong size)
+{
+    uLong ret=0;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+
+    if (hFile != NULL)
+    {
+        if (!WriteFile(hFile, buf, size, &ret, NULL))
+        {
+            DWORD dwErr = GetLastError();
+            if (dwErr == ERROR_HANDLE_EOF)
+                dwErr = 0;
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+        }
+    }
+
+    return ret;
+}
+
+static BOOL MySetFilePointerEx(HANDLE hFile, LARGE_INTEGER pos, LARGE_INTEGER *newPos,  DWORD dwMoveMethod)
+{
+#ifdef IOWIN32_USING_WINRT_API
+    return SetFilePointerEx(hFile, pos, newPos, dwMoveMethod);
+#else
+    LONG lHigh = pos.HighPart;
+    DWORD dwNewPos = SetFilePointer(hFile, pos.LowPart, &lHigh, dwMoveMethod);
+    BOOL fOk = TRUE;
+    if (dwNewPos == 0xFFFFFFFF)
+        if (GetLastError() != NO_ERROR)
+            fOk = FALSE;
+    if ((newPos != NULL) && (fOk))
+    {
+        newPos->LowPart = dwNewPos;
+        newPos->HighPart = lHigh;
+    }
+    return fOk;
+#endif
+}
+
+long ZCALLBACK win32_tell_file_func (voidpf opaque,voidpf stream)
+{
+    long ret=-1;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+    if (hFile != NULL)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = 0;
+
+        if (!MySetFilePointerEx(hFile, pos, &pos, FILE_CURRENT))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = -1;
+        }
+        else
+            ret=(long)pos.LowPart;
+    }
+    return ret;
+}
+
+ZPOS64_T ZCALLBACK win32_tell64_file_func (voidpf opaque, voidpf stream)
+{
+    ZPOS64_T ret= (ZPOS64_T)-1;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream)->hf;
+
+    if (hFile)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = 0;
+
+        if (!MySetFilePointerEx(hFile, pos, &pos, FILE_CURRENT))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = (ZPOS64_T)-1;
+        }
+        else
+            ret=pos.QuadPart;
+    }
+    return ret;
+}
+
+
+long ZCALLBACK win32_seek_file_func (voidpf opaque,voidpf stream,uLong offset,int origin)
+{
+    DWORD dwMoveMethod=0xFFFFFFFF;
+    HANDLE hFile = NULL;
+
+    long ret=-1;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+    switch (origin)
+    {
+    case ZLIB_FILEFUNC_SEEK_CUR :
+        dwMoveMethod = FILE_CURRENT;
+        break;
+    case ZLIB_FILEFUNC_SEEK_END :
+        dwMoveMethod = FILE_END;
+        break;
+    case ZLIB_FILEFUNC_SEEK_SET :
+        dwMoveMethod = FILE_BEGIN;
+        break;
+    default: return -1;
+    }
+
+    if (hFile != NULL)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = offset;
+        if (!MySetFilePointerEx(hFile, pos, NULL, dwMoveMethod))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = -1;
+        }
+        else
+            ret=0;
+    }
+    return ret;
+}
+
+long ZCALLBACK win32_seek64_file_func (voidpf opaque, voidpf stream,ZPOS64_T offset,int origin)
+{
+    DWORD dwMoveMethod=0xFFFFFFFF;
+    HANDLE hFile = NULL;
+    long ret=-1;
+
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream)->hf;
+
+    switch (origin)
+    {
+        case ZLIB_FILEFUNC_SEEK_CUR :
+            dwMoveMethod = FILE_CURRENT;
+            break;
+        case ZLIB_FILEFUNC_SEEK_END :
+            dwMoveMethod = FILE_END;
+            break;
+        case ZLIB_FILEFUNC_SEEK_SET :
+            dwMoveMethod = FILE_BEGIN;
+            break;
+        default: return -1;
+    }
+
+    if (hFile)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = offset;
+        if (!MySetFilePointerEx(hFile, pos, NULL, dwMoveMethod))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = -1;
+        }
+        else
+            ret=0;
+    }
+    return ret;
+}
+
+int ZCALLBACK win32_close_file_func (voidpf opaque, voidpf stream)
+{
+    int ret=-1;
+
+    if (stream!=NULL)
+    {
+        HANDLE hFile;
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+        if (hFile != NULL)
+        {
+            CloseHandle(hFile);
+            ret=0;
+        }
+        free(stream);
+    }
+    return ret;
+}
+
+int ZCALLBACK win32_error_file_func (voidpf opaque,voidpf stream)
+{
+    int ret=-1;
+    if (stream!=NULL)
+    {
+        ret = ((WIN32FILE_IOWIN*)stream) -> error;
+    }
+    return ret;
+}
+
+void fill_win32_filefunc (zlib_filefunc_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen_file = win32_open_file_func;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell_file = win32_tell_file_func;
+    pzlib_filefunc_def->zseek_file = win32_seek_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+void fill_win32_filefunc64(zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = win32_open64_file_func;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell64_file = win32_tell64_file_func;
+    pzlib_filefunc_def->zseek64_file = win32_seek64_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+
+void fill_win32_filefunc64A(zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = win32_open64_file_funcA;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell64_file = win32_tell64_file_func;
+    pzlib_filefunc_def->zseek64_file = win32_seek64_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+
+void fill_win32_filefunc64W(zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = win32_open64_file_funcW;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell64_file = win32_tell64_file_func;
+    pzlib_filefunc_def->zseek64_file = win32_seek64_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
diff --git a/xs/src/png/zlib/contrib/minizip/iowin32.h b/xs/src/png/zlib/contrib/minizip/iowin32.h
new file mode 100644
index 000000000..0ca0969a7
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/iowin32.h
@@ -0,0 +1,28 @@
+/* iowin32.h -- IO base function header for compress/uncompress .zip
+     Version 1.1, February 14h, 2010
+     part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+*/
+
+#include <windows.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void fill_win32_filefunc OF((zlib_filefunc_def* pzlib_filefunc_def));
+void fill_win32_filefunc64 OF((zlib_filefunc64_def* pzlib_filefunc_def));
+void fill_win32_filefunc64A OF((zlib_filefunc64_def* pzlib_filefunc_def));
+void fill_win32_filefunc64W OF((zlib_filefunc64_def* pzlib_filefunc_def));
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/xs/src/png/zlib/contrib/minizip/make_vms.com b/xs/src/png/zlib/contrib/minizip/make_vms.com
new file mode 100644
index 000000000..9ac13a98f
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/make_vms.com
@@ -0,0 +1,25 @@
+$ if f$search("ioapi.h_orig") .eqs. "" then copy ioapi.h ioapi.h_orig
+$ open/write zdef vmsdefs.h
+$ copy sys$input: zdef
+$ deck
+#define unix
+#define fill_zlib_filefunc64_32_def_from_filefunc32 fillzffunc64from
+#define Write_Zip64EndOfCentralDirectoryLocator Write_Zip64EoDLocator
+#define Write_Zip64EndOfCentralDirectoryRecord Write_Zip64EoDRecord
+#define Write_EndOfCentralDirectoryRecord Write_EoDRecord
+$ eod
+$ close zdef
+$ copy vmsdefs.h,ioapi.h_orig ioapi.h
+$ cc/include=[--]/prefix=all ioapi.c
+$ cc/include=[--]/prefix=all miniunz.c
+$ cc/include=[--]/prefix=all unzip.c
+$ cc/include=[--]/prefix=all minizip.c
+$ cc/include=[--]/prefix=all zip.c
+$ link miniunz,unzip,ioapi,[--]libz.olb/lib
+$ link minizip,zip,ioapi,[--]libz.olb/lib
+$ mcr []minizip test minizip_info.txt
+$ mcr []miniunz -l test.zip
+$ rename minizip_info.txt; minizip_info.txt_old
+$ mcr []miniunz test.zip
+$ delete test.zip;*
+$exit
diff --git a/xs/src/png/zlib/contrib/minizip/miniunz.c b/xs/src/png/zlib/contrib/minizip/miniunz.c
new file mode 100644
index 000000000..3d65401be
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/miniunz.c
@@ -0,0 +1,660 @@
+/*
+   miniunz.c
+   Version 1.1, February 14h, 2010
+   sample part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+*/
+
+#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
+        #ifndef __USE_FILE_OFFSET64
+                #define __USE_FILE_OFFSET64
+        #endif
+        #ifndef __USE_LARGEFILE64
+                #define __USE_LARGEFILE64
+        #endif
+        #ifndef _LARGEFILE64_SOURCE
+                #define _LARGEFILE64_SOURCE
+        #endif
+        #ifndef _FILE_OFFSET_BIT
+                #define _FILE_OFFSET_BIT 64
+        #endif
+#endif
+
+#ifdef __APPLE__
+// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
+#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
+#define FTELLO_FUNC(stream) ftello(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
+#else
+#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
+#define FTELLO_FUNC(stream) ftello64(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
+#endif
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#ifdef _WIN32
+# include <direct.h>
+# include <io.h>
+#else
+# include <unistd.h>
+# include <utime.h>
+#endif
+
+
+#include "unzip.h"
+
+#define CASESENSITIVITY (0)
+#define WRITEBUFFERSIZE (8192)
+#define MAXFILENAME (256)
+
+#ifdef _WIN32
+#define USEWIN32IOAPI
+#include "iowin32.h"
+#endif
+/*
+  mini unzip, demo of unzip package
+
+  usage :
+  Usage : miniunz [-exvlo] file.zip [file_to_extract] [-d extractdir]
+
+  list the file in the zipfile, and print the content of FILE_ID.ZIP or README.TXT
+    if it exists
+*/
+
+
+/* change_file_date : change the date/time of a file
+    filename : the filename of the file where date/time must be modified
+    dosdate : the new date at the MSDos format (4 bytes)
+    tmu_date : the SAME new date at the tm_unz format */
+void change_file_date(filename,dosdate,tmu_date)
+    const char *filename;
+    uLong dosdate;
+    tm_unz tmu_date;
+{
+#ifdef _WIN32
+  HANDLE hFile;
+  FILETIME ftm,ftLocal,ftCreate,ftLastAcc,ftLastWrite;
+
+  hFile = CreateFileA(filename,GENERIC_READ | GENERIC_WRITE,
+                      0,NULL,OPEN_EXISTING,0,NULL);
+  GetFileTime(hFile,&ftCreate,&ftLastAcc,&ftLastWrite);
+  DosDateTimeToFileTime((WORD)(dosdate>>16),(WORD)dosdate,&ftLocal);
+  LocalFileTimeToFileTime(&ftLocal,&ftm);
+  SetFileTime(hFile,&ftm,&ftLastAcc,&ftm);
+  CloseHandle(hFile);
+#else
+#ifdef unix || __APPLE__
+  struct utimbuf ut;
+  struct tm newdate;
+  newdate.tm_sec = tmu_date.tm_sec;
+  newdate.tm_min=tmu_date.tm_min;
+  newdate.tm_hour=tmu_date.tm_hour;
+  newdate.tm_mday=tmu_date.tm_mday;
+  newdate.tm_mon=tmu_date.tm_mon;
+  if (tmu_date.tm_year > 1900)
+      newdate.tm_year=tmu_date.tm_year - 1900;
+  else
+      newdate.tm_year=tmu_date.tm_year ;
+  newdate.tm_isdst=-1;
+
+  ut.actime=ut.modtime=mktime(&newdate);
+  utime(filename,&ut);
+#endif
+#endif
+}
+
+
+/* mymkdir and change_file_date are not 100 % portable
+   As I don't know well Unix, I wait feedback for the unix portion */
+
+int mymkdir(dirname)
+    const char* dirname;
+{
+    int ret=0;
+#ifdef _WIN32
+    ret = _mkdir(dirname);
+#elif unix
+    ret = mkdir (dirname,0775);
+#elif __APPLE__
+    ret = mkdir (dirname,0775);
+#endif
+    return ret;
+}
+
+int makedir (newdir)
+    char *newdir;
+{
+  char *buffer ;
+  char *p;
+  int  len = (int)strlen(newdir);
+
+  if (len <= 0)
+    return 0;
+
+  buffer = (char*)malloc(len+1);
+        if (buffer==NULL)
+        {
+                printf("Error allocating memory\n");
+                return UNZ_INTERNALERROR;
+        }
+  strcpy(buffer,newdir);
+
+  if (buffer[len-1] == '/') {
+    buffer[len-1] = '\0';
+  }
+  if (mymkdir(buffer) == 0)
+    {
+      free(buffer);
+      return 1;
+    }
+
+  p = buffer+1;
+  while (1)
+    {
+      char hold;
+
+      while(*p && *p != '\\' && *p != '/')
+        p++;
+      hold = *p;
+      *p = 0;
+      if ((mymkdir(buffer) == -1) && (errno == ENOENT))
+        {
+          printf("couldn't create directory %s\n",buffer);
+          free(buffer);
+          return 0;
+        }
+      if (hold == 0)
+        break;
+      *p++ = hold;
+    }
+  free(buffer);
+  return 1;
+}
+
+void do_banner()
+{
+    printf("MiniUnz 1.01b, demo of zLib + Unz package written by Gilles Vollant\n");
+    printf("more info at http://www.winimage.com/zLibDll/unzip.html\n\n");
+}
+
+void do_help()
+{
+    printf("Usage : miniunz [-e] [-x] [-v] [-l] [-o] [-p password] file.zip [file_to_extr.] [-d extractdir]\n\n" \
+           "  -e  Extract without pathname (junk paths)\n" \
+           "  -x  Extract with pathname\n" \
+           "  -v  list files\n" \
+           "  -l  list files\n" \
+           "  -d  directory to extract into\n" \
+           "  -o  overwrite files without prompting\n" \
+           "  -p  extract crypted file using password\n\n");
+}
+
+void Display64BitsSize(ZPOS64_T n, int size_char)
+{
+  /* to avoid compatibility problem , we do here the conversion */
+  char number[21];
+  int offset=19;
+  int pos_string = 19;
+  number[20]=0;
+  for (;;) {
+      number[offset]=(char)((n%10)+'0');
+      if (number[offset] != '0')
+          pos_string=offset;
+      n/=10;
+      if (offset==0)
+          break;
+      offset--;
+  }
+  {
+      int size_display_string = 19-pos_string;
+      while (size_char > size_display_string)
+      {
+          size_char--;
+          printf(" ");
+      }
+  }
+
+  printf("%s",&number[pos_string]);
+}
+
+int do_list(uf)
+    unzFile uf;
+{
+    uLong i;
+    unz_global_info64 gi;
+    int err;
+
+    err = unzGetGlobalInfo64(uf,&gi);
+    if (err!=UNZ_OK)
+        printf("error %d with zipfile in unzGetGlobalInfo \n",err);
+    printf("  Length  Method     Size Ratio   Date    Time   CRC-32     Name\n");
+    printf("  ------  ------     ---- -----   ----    ----   ------     ----\n");
+    for (i=0;i<gi.number_entry;i++)
+    {
+        char filename_inzip[256];
+        unz_file_info64 file_info;
+        uLong ratio=0;
+        const char *string_method;
+        char charCrypt=' ';
+        err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);
+        if (err!=UNZ_OK)
+        {
+            printf("error %d with zipfile in unzGetCurrentFileInfo\n",err);
+            break;
+        }
+        if (file_info.uncompressed_size>0)
+            ratio = (uLong)((file_info.compressed_size*100)/file_info.uncompressed_size);
+
+        /* display a '*' if the file is crypted */
+        if ((file_info.flag & 1) != 0)
+            charCrypt='*';
+
+        if (file_info.compression_method==0)
+            string_method="Stored";
+        else
+        if (file_info.compression_method==Z_DEFLATED)
+        {
+            uInt iLevel=(uInt)((file_info.flag & 0x6)/2);
+            if (iLevel==0)
+              string_method="Defl:N";
+            else if (iLevel==1)
+              string_method="Defl:X";
+            else if ((iLevel==2) || (iLevel==3))
+              string_method="Defl:F"; /* 2:fast , 3 : extra fast*/
+        }
+        else
+        if (file_info.compression_method==Z_BZIP2ED)
+        {
+              string_method="BZip2 ";
+        }
+        else
+            string_method="Unkn. ";
+
+        Display64BitsSize(file_info.uncompressed_size,7);
+        printf("  %6s%c",string_method,charCrypt);
+        Display64BitsSize(file_info.compressed_size,7);
+        printf(" %3lu%%  %2.2lu-%2.2lu-%2.2lu  %2.2lu:%2.2lu  %8.8lx   %s\n",
+                ratio,
+                (uLong)file_info.tmu_date.tm_mon + 1,
+                (uLong)file_info.tmu_date.tm_mday,
+                (uLong)file_info.tmu_date.tm_year % 100,
+                (uLong)file_info.tmu_date.tm_hour,(uLong)file_info.tmu_date.tm_min,
+                (uLong)file_info.crc,filename_inzip);
+        if ((i+1)<gi.number_entry)
+        {
+            err = unzGoToNextFile(uf);
+            if (err!=UNZ_OK)
+            {
+                printf("error %d with zipfile in unzGoToNextFile\n",err);
+                break;
+            }
+        }
+    }
+
+    return 0;
+}
+
+
+int do_extract_currentfile(uf,popt_extract_without_path,popt_overwrite,password)
+    unzFile uf;
+    const int* popt_extract_without_path;
+    int* popt_overwrite;
+    const char* password;
+{
+    char filename_inzip[256];
+    char* filename_withoutpath;
+    char* p;
+    int err=UNZ_OK;
+    FILE *fout=NULL;
+    void* buf;
+    uInt size_buf;
+
+    unz_file_info64 file_info;
+    uLong ratio=0;
+    err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);
+
+    if (err!=UNZ_OK)
+    {
+        printf("error %d with zipfile in unzGetCurrentFileInfo\n",err);
+        return err;
+    }
+
+    size_buf = WRITEBUFFERSIZE;
+    buf = (void*)malloc(size_buf);
+    if (buf==NULL)
+    {
+        printf("Error allocating memory\n");
+        return UNZ_INTERNALERROR;
+    }
+
+    p = filename_withoutpath = filename_inzip;
+    while ((*p) != '\0')
+    {
+        if (((*p)=='/') || ((*p)=='\\'))
+            filename_withoutpath = p+1;
+        p++;
+    }
+
+    if ((*filename_withoutpath)=='\0')
+    {
+        if ((*popt_extract_without_path)==0)
+        {
+            printf("creating directory: %s\n",filename_inzip);
+            mymkdir(filename_inzip);
+        }
+    }
+    else
+    {
+        const char* write_filename;
+        int skip=0;
+
+        if ((*popt_extract_without_path)==0)
+            write_filename = filename_inzip;
+        else
+            write_filename = filename_withoutpath;
+
+        err = unzOpenCurrentFilePassword(uf,password);
+        if (err!=UNZ_OK)
+        {
+            printf("error %d with zipfile in unzOpenCurrentFilePassword\n",err);
+        }
+
+        if (((*popt_overwrite)==0) && (err==UNZ_OK))
+        {
+            char rep=0;
+            FILE* ftestexist;
+            ftestexist = FOPEN_FUNC(write_filename,"rb");
+            if (ftestexist!=NULL)
+            {
+                fclose(ftestexist);
+                do
+                {
+                    char answer[128];
+                    int ret;
+
+                    printf("The file %s exists. Overwrite ? [y]es, [n]o, [A]ll: ",write_filename);
+                    ret = scanf("%1s",answer);
+                    if (ret != 1)
+                    {
+                       exit(EXIT_FAILURE);
+                    }
+                    rep = answer[0] ;
+                    if ((rep>='a') && (rep<='z'))
+                        rep -= 0x20;
+                }
+                while ((rep!='Y') && (rep!='N') && (rep!='A'));
+            }
+
+            if (rep == 'N')
+                skip = 1;
+
+            if (rep == 'A')
+                *popt_overwrite=1;
+        }
+
+        if ((skip==0) && (err==UNZ_OK))
+        {
+            fout=FOPEN_FUNC(write_filename,"wb");
+            /* some zipfile don't contain directory alone before file */
+            if ((fout==NULL) && ((*popt_extract_without_path)==0) &&
+                                (filename_withoutpath!=(char*)filename_inzip))
+            {
+                char c=*(filename_withoutpath-1);
+                *(filename_withoutpath-1)='\0';
+                makedir(write_filename);
+                *(filename_withoutpath-1)=c;
+                fout=FOPEN_FUNC(write_filename,"wb");
+            }
+
+            if (fout==NULL)
+            {
+                printf("error opening %s\n",write_filename);
+            }
+        }
+
+        if (fout!=NULL)
+        {
+            printf(" extracting: %s\n",write_filename);
+
+            do
+            {
+                err = unzReadCurrentFile(uf,buf,size_buf);
+                if (err<0)
+                {
+                    printf("error %d with zipfile in unzReadCurrentFile\n",err);
+                    break;
+                }
+                if (err>0)
+                    if (fwrite(buf,err,1,fout)!=1)
+                    {
+                        printf("error in writing extracted file\n");
+                        err=UNZ_ERRNO;
+                        break;
+                    }
+            }
+            while (err>0);
+            if (fout)
+                    fclose(fout);
+
+            if (err==0)
+                change_file_date(write_filename,file_info.dosDate,
+                                 file_info.tmu_date);
+        }
+
+        if (err==UNZ_OK)
+        {
+            err = unzCloseCurrentFile (uf);
+            if (err!=UNZ_OK)
+            {
+                printf("error %d with zipfile in unzCloseCurrentFile\n",err);
+            }
+        }
+        else
+            unzCloseCurrentFile(uf); /* don't lose the error */
+    }
+
+    free(buf);
+    return err;
+}
+
+
+int do_extract(uf,opt_extract_without_path,opt_overwrite,password)
+    unzFile uf;
+    int opt_extract_without_path;
+    int opt_overwrite;
+    const char* password;
+{
+    uLong i;
+    unz_global_info64 gi;
+    int err;
+    FILE* fout=NULL;
+
+    err = unzGetGlobalInfo64(uf,&gi);
+    if (err!=UNZ_OK)
+        printf("error %d with zipfile in unzGetGlobalInfo \n",err);
+
+    for (i=0;i<gi.number_entry;i++)
+    {
+        if (do_extract_currentfile(uf,&opt_extract_without_path,
+                                      &opt_overwrite,
+                                      password) != UNZ_OK)
+            break;
+
+        if ((i+1)<gi.number_entry)
+        {
+            err = unzGoToNextFile(uf);
+            if (err!=UNZ_OK)
+            {
+                printf("error %d with zipfile in unzGoToNextFile\n",err);
+                break;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int do_extract_onefile(uf,filename,opt_extract_without_path,opt_overwrite,password)
+    unzFile uf;
+    const char* filename;
+    int opt_extract_without_path;
+    int opt_overwrite;
+    const char* password;
+{
+    int err = UNZ_OK;
+    if (unzLocateFile(uf,filename,CASESENSITIVITY)!=UNZ_OK)
+    {
+        printf("file %s not found in the zipfile\n",filename);
+        return 2;
+    }
+
+    if (do_extract_currentfile(uf,&opt_extract_without_path,
+                                      &opt_overwrite,
+                                      password) == UNZ_OK)
+        return 0;
+    else
+        return 1;
+}
+
+
+int main(argc,argv)
+    int argc;
+    char *argv[];
+{
+    const char *zipfilename=NULL;
+    const char *filename_to_extract=NULL;
+    const char *password=NULL;
+    char filename_try[MAXFILENAME+16] = "";
+    int i;
+    int ret_value=0;
+    int opt_do_list=0;
+    int opt_do_extract=1;
+    int opt_do_extract_withoutpath=0;
+    int opt_overwrite=0;
+    int opt_extractdir=0;
+    const char *dirname=NULL;
+    unzFile uf=NULL;
+
+    do_banner();
+    if (argc==1)
+    {
+        do_help();
+        return 0;
+    }
+    else
+    {
+        for (i=1;i<argc;i++)
+        {
+            if ((*argv[i])=='-')
+            {
+                const char *p=argv[i]+1;
+
+                while ((*p)!='\0')
+                {
+                    char c=*(p++);;
+                    if ((c=='l') || (c=='L'))
+                        opt_do_list = 1;
+                    if ((c=='v') || (c=='V'))
+                        opt_do_list = 1;
+                    if ((c=='x') || (c=='X'))
+                        opt_do_extract = 1;
+                    if ((c=='e') || (c=='E'))
+                        opt_do_extract = opt_do_extract_withoutpath = 1;
+                    if ((c=='o') || (c=='O'))
+                        opt_overwrite=1;
+                    if ((c=='d') || (c=='D'))
+                    {
+                        opt_extractdir=1;
+                        dirname=argv[i+1];
+                    }
+
+                    if (((c=='p') || (c=='P')) && (i+1<argc))
+                    {
+                        password=argv[i+1];
+                        i++;
+                    }
+                }
+            }
+            else
+            {
+                if (zipfilename == NULL)
+                    zipfilename = argv[i];
+                else if ((filename_to_extract==NULL) && (!opt_extractdir))
+                        filename_to_extract = argv[i] ;
+            }
+        }
+    }
+
+    if (zipfilename!=NULL)
+    {
+
+#        ifdef USEWIN32IOAPI
+        zlib_filefunc64_def ffunc;
+#        endif
+
+        strncpy(filename_try, zipfilename,MAXFILENAME-1);
+        /* strncpy doesnt append the trailing NULL, of the string is too long. */
+        filename_try[ MAXFILENAME ] = '\0';
+
+#        ifdef USEWIN32IOAPI
+        fill_win32_filefunc64A(&ffunc);
+        uf = unzOpen2_64(zipfilename,&ffunc);
+#        else
+        uf = unzOpen64(zipfilename);
+#        endif
+        if (uf==NULL)
+        {
+            strcat(filename_try,".zip");
+#            ifdef USEWIN32IOAPI
+            uf = unzOpen2_64(filename_try,&ffunc);
+#            else
+            uf = unzOpen64(filename_try);
+#            endif
+        }
+    }
+
+    if (uf==NULL)
+    {
+        printf("Cannot open %s or %s.zip\n",zipfilename,zipfilename);
+        return 1;
+    }
+    printf("%s opened\n",filename_try);
+
+    if (opt_do_list==1)
+        ret_value = do_list(uf);
+    else if (opt_do_extract==1)
+    {
+#ifdef _WIN32
+        if (opt_extractdir && _chdir(dirname))
+#else
+        if (opt_extractdir && chdir(dirname))
+#endif
+        {
+          printf("Error changing into %s, aborting\n", dirname);
+          exit(-1);
+        }
+
+        if (filename_to_extract == NULL)
+            ret_value = do_extract(uf, opt_do_extract_withoutpath, opt_overwrite, password);
+        else
+            ret_value = do_extract_onefile(uf, filename_to_extract, opt_do_extract_withoutpath, opt_overwrite, password);
+    }
+
+    unzClose(uf);
+
+    return ret_value;
+}
diff --git a/xs/src/png/zlib/contrib/minizip/miniunzip.1 b/xs/src/png/zlib/contrib/minizip/miniunzip.1
new file mode 100644
index 000000000..111ac6919
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/miniunzip.1
@@ -0,0 +1,63 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.TH miniunzip 1 "Nov 7, 2001"
+.\" Please adjust this date whenever revising the manpage.
+.\"
+.\" Some roff macros, for reference:
+.\" .nh        disable hyphenation
+.\" .hy        enable hyphenation
+.\" .ad l      left justify
+.\" .ad b      justify to both left and right margins
+.\" .nf        disable filling
+.\" .fi        enable filling
+.\" .br        insert line break
+.\" .sp <n>    insert n+1 empty lines
+.\" for manpage-specific macros, see man(7)
+.SH NAME
+miniunzip - uncompress and examine ZIP archives
+.SH SYNOPSIS
+.B miniunzip
+.RI [ -exvlo ]
+zipfile [ files_to_extract ] [-d tempdir]
+.SH DESCRIPTION
+.B minizip
+is a simple tool which allows the extraction of compressed file
+archives in the ZIP format used by the MS-DOS utility PKZIP.  It was
+written as a demonstration of the
+.IR zlib (3)
+library and therefore lack many of the features of the
+.IR unzip (1)
+program.
+.SH OPTIONS
+A number of options are supported.  With the exception of
+.BI \-d\  tempdir
+these must be supplied before any
+other arguments and are:
+.TP
+.BI \-l\ ,\ \-\-v
+List the files in the archive without extracting them.
+.TP
+.B \-o
+Overwrite files without prompting for confirmation.
+.TP
+.B \-x
+Extract files (default).
+.PP
+The
+.I zipfile
+argument is the name of the archive to process. The next argument can be used
+to specify a single file to extract from the archive.
+
+Lastly, the following option can be specified at the end of the command-line:
+.TP
+.BI \-d\  tempdir
+Extract the archive in the directory
+.I tempdir
+rather than the current directory.
+.SH SEE ALSO
+.BR minizip (1),
+.BR zlib (3),
+.BR unzip (1).
+.SH AUTHOR
+This program was written by Gilles Vollant.  This manual page was
+written by Mark Brown <broonie@sirena.org.uk>. The -d tempdir option
+was added by Dirk Eddelbuettel <edd@debian.org>.
diff --git a/xs/src/png/zlib/contrib/minizip/minizip.1 b/xs/src/png/zlib/contrib/minizip/minizip.1
new file mode 100644
index 000000000..1154484c1
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/minizip.1
@@ -0,0 +1,46 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.TH minizip 1 "May 2, 2001"
+.\" Please adjust this date whenever revising the manpage.
+.\"
+.\" Some roff macros, for reference:
+.\" .nh        disable hyphenation
+.\" .hy        enable hyphenation
+.\" .ad l      left justify
+.\" .ad b      justify to both left and right margins
+.\" .nf        disable filling
+.\" .fi        enable filling
+.\" .br        insert line break
+.\" .sp <n>    insert n+1 empty lines
+.\" for manpage-specific macros, see man(7)
+.SH NAME
+minizip - create ZIP archives
+.SH SYNOPSIS
+.B minizip
+.RI [ -o ]
+zipfile [ " files" ... ]
+.SH DESCRIPTION
+.B minizip
+is a simple tool which allows the creation of compressed file archives
+in the ZIP format used by the MS-DOS utility PKZIP.  It was written as
+a demonstration of the
+.IR zlib (3)
+library and therefore lack many of the features of the
+.IR zip (1)
+program.
+.SH OPTIONS
+The first argument supplied is the name of the ZIP archive to create or
+.RI -o
+in which case it is ignored and the second argument treated as the
+name of the ZIP file.  If the ZIP file already exists it will be
+overwritten.
+.PP
+Subsequent arguments specify a list of files to place in the ZIP
+archive.  If none are specified then an empty archive will be created.
+.SH SEE ALSO
+.BR miniunzip (1),
+.BR zlib (3),
+.BR zip (1).
+.SH AUTHOR
+This program was written by Gilles Vollant.  This manual page was
+written by Mark Brown <broonie@sirena.org.uk>.
+
diff --git a/xs/src/png/zlib/contrib/minizip/minizip.c b/xs/src/png/zlib/contrib/minizip/minizip.c
new file mode 100644
index 000000000..4288962ec
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/minizip.c
@@ -0,0 +1,520 @@
+/*
+   minizip.c
+   Version 1.1, February 14h, 2010
+   sample part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+*/
+
+
+#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
+        #ifndef __USE_FILE_OFFSET64
+                #define __USE_FILE_OFFSET64
+        #endif
+        #ifndef __USE_LARGEFILE64
+                #define __USE_LARGEFILE64
+        #endif
+        #ifndef _LARGEFILE64_SOURCE
+                #define _LARGEFILE64_SOURCE
+        #endif
+        #ifndef _FILE_OFFSET_BIT
+                #define _FILE_OFFSET_BIT 64
+        #endif
+#endif
+
+#ifdef __APPLE__
+// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
+#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
+#define FTELLO_FUNC(stream) ftello(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
+#else
+#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
+#define FTELLO_FUNC(stream) ftello64(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
+#endif
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#ifdef _WIN32
+# include <direct.h>
+# include <io.h>
+#else
+# include <unistd.h>
+# include <utime.h>
+# include <sys/types.h>
+# include <sys/stat.h>
+#endif
+
+#include "zip.h"
+
+#ifdef _WIN32
+        #define USEWIN32IOAPI
+        #include "iowin32.h"
+#endif
+
+
+
+#define WRITEBUFFERSIZE (16384)
+#define MAXFILENAME (256)
+
+#ifdef _WIN32
+uLong filetime(f, tmzip, dt)
+    char *f;                /* name of file to get info on */
+    tm_zip *tmzip;             /* return value: access, modific. and creation times */
+    uLong *dt;             /* dostime */
+{
+  int ret = 0;
+  {
+      FILETIME ftLocal;
+      HANDLE hFind;
+      WIN32_FIND_DATAA ff32;
+
+      hFind = FindFirstFileA(f,&ff32);
+      if (hFind != INVALID_HANDLE_VALUE)
+      {
+        FileTimeToLocalFileTime(&(ff32.ftLastWriteTime),&ftLocal);
+        FileTimeToDosDateTime(&ftLocal,((LPWORD)dt)+1,((LPWORD)dt)+0);
+        FindClose(hFind);
+        ret = 1;
+      }
+  }
+  return ret;
+}
+#else
+#ifdef unix || __APPLE__
+uLong filetime(f, tmzip, dt)
+    char *f;               /* name of file to get info on */
+    tm_zip *tmzip;         /* return value: access, modific. and creation times */
+    uLong *dt;             /* dostime */
+{
+  int ret=0;
+  struct stat s;        /* results of stat() */
+  struct tm* filedate;
+  time_t tm_t=0;
+
+  if (strcmp(f,"-")!=0)
+  {
+    char name[MAXFILENAME+1];
+    int len = strlen(f);
+    if (len > MAXFILENAME)
+      len = MAXFILENAME;
+
+    strncpy(name, f,MAXFILENAME-1);
+    /* strncpy doesnt append the trailing NULL, of the string is too long. */
+    name[ MAXFILENAME ] = '\0';
+
+    if (name[len - 1] == '/')
+      name[len - 1] = '\0';
+    /* not all systems allow stat'ing a file with / appended */
+    if (stat(name,&s)==0)
+    {
+      tm_t = s.st_mtime;
+      ret = 1;
+    }
+  }
+  filedate = localtime(&tm_t);
+
+  tmzip->tm_sec  = filedate->tm_sec;
+  tmzip->tm_min  = filedate->tm_min;
+  tmzip->tm_hour = filedate->tm_hour;
+  tmzip->tm_mday = filedate->tm_mday;
+  tmzip->tm_mon  = filedate->tm_mon ;
+  tmzip->tm_year = filedate->tm_year;
+
+  return ret;
+}
+#else
+uLong filetime(f, tmzip, dt)
+    char *f;                /* name of file to get info on */
+    tm_zip *tmzip;             /* return value: access, modific. and creation times */
+    uLong *dt;             /* dostime */
+{
+    return 0;
+}
+#endif
+#endif
+
+
+
+
+int check_exist_file(filename)
+    const char* filename;
+{
+    FILE* ftestexist;
+    int ret = 1;
+    ftestexist = FOPEN_FUNC(filename,"rb");
+    if (ftestexist==NULL)
+        ret = 0;
+    else
+        fclose(ftestexist);
+    return ret;
+}
+
+void do_banner()
+{
+    printf("MiniZip 1.1, demo of zLib + MiniZip64 package, written by Gilles Vollant\n");
+    printf("more info on MiniZip at http://www.winimage.com/zLibDll/minizip.html\n\n");
+}
+
+void do_help()
+{
+    printf("Usage : minizip [-o] [-a] [-0 to -9] [-p password] [-j] file.zip [files_to_add]\n\n" \
+           "  -o  Overwrite existing file.zip\n" \
+           "  -a  Append to existing file.zip\n" \
+           "  -0  Store only\n" \
+           "  -1  Compress faster\n" \
+           "  -9  Compress better\n\n" \
+           "  -j  exclude path. store only the file name.\n\n");
+}
+
+/* calculate the CRC32 of a file,
+   because to encrypt a file, we need known the CRC32 of the file before */
+int getFileCrc(const char* filenameinzip,void*buf,unsigned long size_buf,unsigned long* result_crc)
+{
+   unsigned long calculate_crc=0;
+   int err=ZIP_OK;
+   FILE * fin = FOPEN_FUNC(filenameinzip,"rb");
+
+   unsigned long size_read = 0;
+   unsigned long total_read = 0;
+   if (fin==NULL)
+   {
+       err = ZIP_ERRNO;
+   }
+
+    if (err == ZIP_OK)
+        do
+        {
+            err = ZIP_OK;
+            size_read = (int)fread(buf,1,size_buf,fin);
+            if (size_read < size_buf)
+                if (feof(fin)==0)
+            {
+                printf("error in reading %s\n",filenameinzip);
+                err = ZIP_ERRNO;
+            }
+
+            if (size_read>0)
+                calculate_crc = crc32(calculate_crc,buf,size_read);
+            total_read += size_read;
+
+        } while ((err == ZIP_OK) && (size_read>0));
+
+    if (fin)
+        fclose(fin);
+
+    *result_crc=calculate_crc;
+    printf("file %s crc %lx\n", filenameinzip, calculate_crc);
+    return err;
+}
+
+int isLargeFile(const char* filename)
+{
+  int largeFile = 0;
+  ZPOS64_T pos = 0;
+  FILE* pFile = FOPEN_FUNC(filename, "rb");
+
+  if(pFile != NULL)
+  {
+    int n = FSEEKO_FUNC(pFile, 0, SEEK_END);
+    pos = FTELLO_FUNC(pFile);
+
+                printf("File : %s is %lld bytes\n", filename, pos);
+
+    if(pos >= 0xffffffff)
+     largeFile = 1;
+
+                fclose(pFile);
+  }
+
+ return largeFile;
+}
+
+int main(argc,argv)
+    int argc;
+    char *argv[];
+{
+    int i;
+    int opt_overwrite=0;
+    int opt_compress_level=Z_DEFAULT_COMPRESSION;
+    int opt_exclude_path=0;
+    int zipfilenamearg = 0;
+    char filename_try[MAXFILENAME+16];
+    int zipok;
+    int err=0;
+    int size_buf=0;
+    void* buf=NULL;
+    const char* password=NULL;
+
+
+    do_banner();
+    if (argc==1)
+    {
+        do_help();
+        return 0;
+    }
+    else
+    {
+        for (i=1;i<argc;i++)
+        {
+            if ((*argv[i])=='-')
+            {
+                const char *p=argv[i]+1;
+
+                while ((*p)!='\0')
+                {
+                    char c=*(p++);;
+                    if ((c=='o') || (c=='O'))
+                        opt_overwrite = 1;
+                    if ((c=='a') || (c=='A'))
+                        opt_overwrite = 2;
+                    if ((c>='0') && (c<='9'))
+                        opt_compress_level = c-'0';
+                    if ((c=='j') || (c=='J'))
+                        opt_exclude_path = 1;
+
+                    if (((c=='p') || (c=='P')) && (i+1<argc))
+                    {
+                        password=argv[i+1];
+                        i++;
+                    }
+                }
+            }
+            else
+            {
+                if (zipfilenamearg == 0)
+                {
+                    zipfilenamearg = i ;
+                }
+            }
+        }
+    }
+
+    size_buf = WRITEBUFFERSIZE;
+    buf = (void*)malloc(size_buf);
+    if (buf==NULL)
+    {
+        printf("Error allocating memory\n");
+        return ZIP_INTERNALERROR;
+    }
+
+    if (zipfilenamearg==0)
+    {
+        zipok=0;
+    }
+    else
+    {
+        int i,len;
+        int dot_found=0;
+
+        zipok = 1 ;
+        strncpy(filename_try, argv[zipfilenamearg],MAXFILENAME-1);
+        /* strncpy doesnt append the trailing NULL, of the string is too long. */
+        filename_try[ MAXFILENAME ] = '\0';
+
+        len=(int)strlen(filename_try);
+        for (i=0;i<len;i++)
+            if (filename_try[i]=='.')
+                dot_found=1;
+
+        if (dot_found==0)
+            strcat(filename_try,".zip");
+
+        if (opt_overwrite==2)
+        {
+            /* if the file don't exist, we not append file */
+            if (check_exist_file(filename_try)==0)
+                opt_overwrite=1;
+        }
+        else
+        if (opt_overwrite==0)
+            if (check_exist_file(filename_try)!=0)
+            {
+                char rep=0;
+                do
+                {
+                    char answer[128];
+                    int ret;
+                    printf("The file %s exists. Overwrite ? [y]es, [n]o, [a]ppend : ",filename_try);
+                    ret = scanf("%1s",answer);
+                    if (ret != 1)
+                    {
+                       exit(EXIT_FAILURE);
+                    }
+                    rep = answer[0] ;
+                    if ((rep>='a') && (rep<='z'))
+                        rep -= 0x20;
+                }
+                while ((rep!='Y') && (rep!='N') && (rep!='A'));
+                if (rep=='N')
+                    zipok = 0;
+                if (rep=='A')
+                    opt_overwrite = 2;
+            }
+    }
+
+    if (zipok==1)
+    {
+        zipFile zf;
+        int errclose;
+#        ifdef USEWIN32IOAPI
+        zlib_filefunc64_def ffunc;
+        fill_win32_filefunc64A(&ffunc);
+        zf = zipOpen2_64(filename_try,(opt_overwrite==2) ? 2 : 0,NULL,&ffunc);
+#        else
+        zf = zipOpen64(filename_try,(opt_overwrite==2) ? 2 : 0);
+#        endif
+
+        if (zf == NULL)
+        {
+            printf("error opening %s\n",filename_try);
+            err= ZIP_ERRNO;
+        }
+        else
+            printf("creating %s\n",filename_try);
+
+        for (i=zipfilenamearg+1;(i<argc) && (err==ZIP_OK);i++)
+        {
+            if (!((((*(argv[i]))=='-') || ((*(argv[i]))=='/')) &&
+                  ((argv[i][1]=='o') || (argv[i][1]=='O') ||
+                   (argv[i][1]=='a') || (argv[i][1]=='A') ||
+                   (argv[i][1]=='p') || (argv[i][1]=='P') ||
+                   ((argv[i][1]>='0') || (argv[i][1]<='9'))) &&
+                  (strlen(argv[i]) == 2)))
+            {
+                FILE * fin;
+                int size_read;
+                const char* filenameinzip = argv[i];
+                const char *savefilenameinzip;
+                zip_fileinfo zi;
+                unsigned long crcFile=0;
+                int zip64 = 0;
+
+                zi.tmz_date.tm_sec = zi.tmz_date.tm_min = zi.tmz_date.tm_hour =
+                zi.tmz_date.tm_mday = zi.tmz_date.tm_mon = zi.tmz_date.tm_year = 0;
+                zi.dosDate = 0;
+                zi.internal_fa = 0;
+                zi.external_fa = 0;
+                filetime(filenameinzip,&zi.tmz_date,&zi.dosDate);
+
+/*
+                err = zipOpenNewFileInZip(zf,filenameinzip,&zi,
+                                 NULL,0,NULL,0,NULL / * comment * /,
+                                 (opt_compress_level != 0) ? Z_DEFLATED : 0,
+                                 opt_compress_level);
+*/
+                if ((password != NULL) && (err==ZIP_OK))
+                    err = getFileCrc(filenameinzip,buf,size_buf,&crcFile);
+
+                zip64 = isLargeFile(filenameinzip);
+
+                                                         /* The path name saved, should not include a leading slash. */
+               /*if it did, windows/xp and dynazip couldn't read the zip file. */
+                 savefilenameinzip = filenameinzip;
+                 while( savefilenameinzip[0] == '\\' || savefilenameinzip[0] == '/' )
+                 {
+                     savefilenameinzip++;
+                 }
+
+                 /*should the zip file contain any path at all?*/
+                 if( opt_exclude_path )
+                 {
+                     const char *tmpptr;
+                     const char *lastslash = 0;
+                     for( tmpptr = savefilenameinzip; *tmpptr; tmpptr++)
+                     {
+                         if( *tmpptr == '\\' || *tmpptr == '/')
+                         {
+                             lastslash = tmpptr;
+                         }
+                     }
+                     if( lastslash != NULL )
+                     {
+                         savefilenameinzip = lastslash+1; // base filename follows last slash.
+                     }
+                 }
+
+                 /**/
+                err = zipOpenNewFileInZip3_64(zf,savefilenameinzip,&zi,
+                                 NULL,0,NULL,0,NULL /* comment*/,
+                                 (opt_compress_level != 0) ? Z_DEFLATED : 0,
+                                 opt_compress_level,0,
+                                 /* -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, */
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 password,crcFile, zip64);
+
+                if (err != ZIP_OK)
+                    printf("error in opening %s in zipfile\n",filenameinzip);
+                else
+                {
+                    fin = FOPEN_FUNC(filenameinzip,"rb");
+                    if (fin==NULL)
+                    {
+                        err=ZIP_ERRNO;
+                        printf("error in opening %s for reading\n",filenameinzip);
+                    }
+                }
+
+                if (err == ZIP_OK)
+                    do
+                    {
+                        err = ZIP_OK;
+                        size_read = (int)fread(buf,1,size_buf,fin);
+                        if (size_read < size_buf)
+                            if (feof(fin)==0)
+                        {
+                            printf("error in reading %s\n",filenameinzip);
+                            err = ZIP_ERRNO;
+                        }
+
+                        if (size_read>0)
+                        {
+                            err = zipWriteInFileInZip (zf,buf,size_read);
+                            if (err<0)
+                            {
+                                printf("error in writing %s in the zipfile\n",
+                                                 filenameinzip);
+                            }
+
+                        }
+                    } while ((err == ZIP_OK) && (size_read>0));
+
+                if (fin)
+                    fclose(fin);
+
+                if (err<0)
+                    err=ZIP_ERRNO;
+                else
+                {
+                    err = zipCloseFileInZip(zf);
+                    if (err!=ZIP_OK)
+                        printf("error in closing %s in the zipfile\n",
+                                    filenameinzip);
+                }
+            }
+        }
+        errclose = zipClose(zf,NULL);
+        if (errclose != ZIP_OK)
+            printf("error in closing %s\n",filename_try);
+    }
+    else
+    {
+       do_help();
+    }
+
+    free(buf);
+    return 0;
+}
diff --git a/xs/src/png/zlib/contrib/minizip/minizip.pc.in b/xs/src/png/zlib/contrib/minizip/minizip.pc.in
new file mode 100644
index 000000000..69b5b7fdc
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/minizip.pc.in
@@ -0,0 +1,12 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/minizip
+
+Name: minizip
+Description: Minizip zip file manipulation library
+Requires:
+Version: @PACKAGE_VERSION@
+Libs: -L${libdir} -lminizip
+Libs.private: -lz
+Cflags: -I${includedir}
diff --git a/xs/src/png/zlib/contrib/minizip/mztools.c b/xs/src/png/zlib/contrib/minizip/mztools.c
new file mode 100644
index 000000000..96891c2e0
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/mztools.c
@@ -0,0 +1,291 @@
+/*
+  Additional tools for Minizip
+  Code: Xavier Roche '2004
+  License: Same as ZLIB (www.gzip.org)
+*/
+
+/* Code */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "zlib.h"
+#include "unzip.h"
+
+#define READ_8(adr)  ((unsigned char)*(adr))
+#define READ_16(adr) ( READ_8(adr) | (READ_8(adr+1) << 8) )
+#define READ_32(adr) ( READ_16(adr) | (READ_16((adr)+2) << 16) )
+
+#define WRITE_8(buff, n) do { \
+  *((unsigned char*)(buff)) = (unsigned char) ((n) & 0xff); \
+} while(0)
+#define WRITE_16(buff, n) do { \
+  WRITE_8((unsigned char*)(buff), n); \
+  WRITE_8(((unsigned char*)(buff)) + 1, (n) >> 8); \
+} while(0)
+#define WRITE_32(buff, n) do { \
+  WRITE_16((unsigned char*)(buff), (n) & 0xffff); \
+  WRITE_16((unsigned char*)(buff) + 2, (n) >> 16); \
+} while(0)
+
+extern int ZEXPORT unzRepair(file, fileOut, fileOutTmp, nRecovered, bytesRecovered)
+const char* file;
+const char* fileOut;
+const char* fileOutTmp;
+uLong* nRecovered;
+uLong* bytesRecovered;
+{
+  int err = Z_OK;
+  FILE* fpZip = fopen(file, "rb");
+  FILE* fpOut = fopen(fileOut, "wb");
+  FILE* fpOutCD = fopen(fileOutTmp, "wb");
+  if (fpZip != NULL &&  fpOut != NULL) {
+    int entries = 0;
+    uLong totalBytes = 0;
+    char header[30];
+    char filename[1024];
+    char extra[1024];
+    int offset = 0;
+    int offsetCD = 0;
+    while ( fread(header, 1, 30, fpZip) == 30 ) {
+      int currentOffset = offset;
+
+      /* File entry */
+      if (READ_32(header) == 0x04034b50) {
+        unsigned int version = READ_16(header + 4);
+        unsigned int gpflag = READ_16(header + 6);
+        unsigned int method = READ_16(header + 8);
+        unsigned int filetime = READ_16(header + 10);
+        unsigned int filedate = READ_16(header + 12);
+        unsigned int crc = READ_32(header + 14); /* crc */
+        unsigned int cpsize = READ_32(header + 18); /* compressed size */
+        unsigned int uncpsize = READ_32(header + 22); /* uncompressed sz */
+        unsigned int fnsize = READ_16(header + 26); /* file name length */
+        unsigned int extsize = READ_16(header + 28); /* extra field length */
+        filename[0] = extra[0] = '\0';
+
+        /* Header */
+        if (fwrite(header, 1, 30, fpOut) == 30) {
+          offset += 30;
+        } else {
+          err = Z_ERRNO;
+          break;
+        }
+
+        /* Filename */
+        if (fnsize > 0) {
+          if (fnsize < sizeof(filename)) {
+            if (fread(filename, 1, fnsize, fpZip) == fnsize) {
+                if (fwrite(filename, 1, fnsize, fpOut) == fnsize) {
+                offset += fnsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            } else {
+              err = Z_ERRNO;
+              break;
+            }
+          } else {
+            err = Z_ERRNO;
+            break;
+          }
+        } else {
+          err = Z_STREAM_ERROR;
+          break;
+        }
+
+        /* Extra field */
+        if (extsize > 0) {
+          if (extsize < sizeof(extra)) {
+            if (fread(extra, 1, extsize, fpZip) == extsize) {
+              if (fwrite(extra, 1, extsize, fpOut) == extsize) {
+                offset += extsize;
+                } else {
+                err = Z_ERRNO;
+                break;
+              }
+            } else {
+              err = Z_ERRNO;
+              break;
+            }
+          } else {
+            err = Z_ERRNO;
+            break;
+          }
+        }
+
+        /* Data */
+        {
+          int dataSize = cpsize;
+          if (dataSize == 0) {
+            dataSize = uncpsize;
+          }
+          if (dataSize > 0) {
+            char* data = malloc(dataSize);
+            if (data != NULL) {
+              if ((int)fread(data, 1, dataSize, fpZip) == dataSize) {
+                if ((int)fwrite(data, 1, dataSize, fpOut) == dataSize) {
+                  offset += dataSize;
+                  totalBytes += dataSize;
+                } else {
+                  err = Z_ERRNO;
+                }
+              } else {
+                err = Z_ERRNO;
+              }
+              free(data);
+              if (err != Z_OK) {
+                break;
+              }
+            } else {
+              err = Z_MEM_ERROR;
+              break;
+            }
+          }
+        }
+
+        /* Central directory entry */
+        {
+          char header[46];
+          char* comment = "";
+          int comsize = (int) strlen(comment);
+          WRITE_32(header, 0x02014b50);
+          WRITE_16(header + 4, version);
+          WRITE_16(header + 6, version);
+          WRITE_16(header + 8, gpflag);
+          WRITE_16(header + 10, method);
+          WRITE_16(header + 12, filetime);
+          WRITE_16(header + 14, filedate);
+          WRITE_32(header + 16, crc);
+          WRITE_32(header + 20, cpsize);
+          WRITE_32(header + 24, uncpsize);
+          WRITE_16(header + 28, fnsize);
+          WRITE_16(header + 30, extsize);
+          WRITE_16(header + 32, comsize);
+          WRITE_16(header + 34, 0);     /* disk # */
+          WRITE_16(header + 36, 0);     /* int attrb */
+          WRITE_32(header + 38, 0);     /* ext attrb */
+          WRITE_32(header + 42, currentOffset);
+          /* Header */
+          if (fwrite(header, 1, 46, fpOutCD) == 46) {
+            offsetCD += 46;
+
+            /* Filename */
+            if (fnsize > 0) {
+              if (fwrite(filename, 1, fnsize, fpOutCD) == fnsize) {
+                offsetCD += fnsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            } else {
+              err = Z_STREAM_ERROR;
+              break;
+            }
+
+            /* Extra field */
+            if (extsize > 0) {
+              if (fwrite(extra, 1, extsize, fpOutCD) == extsize) {
+                offsetCD += extsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            }
+
+            /* Comment field */
+            if (comsize > 0) {
+              if ((int)fwrite(comment, 1, comsize, fpOutCD) == comsize) {
+                offsetCD += comsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            }
+
+
+          } else {
+            err = Z_ERRNO;
+            break;
+          }
+        }
+
+        /* Success */
+        entries++;
+
+      } else {
+        break;
+      }
+    }
+
+    /* Final central directory  */
+    {
+      int entriesZip = entries;
+      char header[22];
+      char* comment = ""; // "ZIP File recovered by zlib/minizip/mztools";
+      int comsize = (int) strlen(comment);
+      if (entriesZip > 0xffff) {
+        entriesZip = 0xffff;
+      }
+      WRITE_32(header, 0x06054b50);
+      WRITE_16(header + 4, 0);    /* disk # */
+      WRITE_16(header + 6, 0);    /* disk # */
+      WRITE_16(header + 8, entriesZip);   /* hack */
+      WRITE_16(header + 10, entriesZip);  /* hack */
+      WRITE_32(header + 12, offsetCD);    /* size of CD */
+      WRITE_32(header + 16, offset);      /* offset to CD */
+      WRITE_16(header + 20, comsize);     /* comment */
+
+      /* Header */
+      if (fwrite(header, 1, 22, fpOutCD) == 22) {
+
+        /* Comment field */
+        if (comsize > 0) {
+          if ((int)fwrite(comment, 1, comsize, fpOutCD) != comsize) {
+            err = Z_ERRNO;
+          }
+        }
+
+      } else {
+        err = Z_ERRNO;
+      }
+    }
+
+    /* Final merge (file + central directory) */
+    fclose(fpOutCD);
+    if (err == Z_OK) {
+      fpOutCD = fopen(fileOutTmp, "rb");
+      if (fpOutCD != NULL) {
+        int nRead;
+        char buffer[8192];
+        while ( (nRead = (int)fread(buffer, 1, sizeof(buffer), fpOutCD)) > 0) {
+          if ((int)fwrite(buffer, 1, nRead, fpOut) != nRead) {
+            err = Z_ERRNO;
+            break;
+          }
+        }
+        fclose(fpOutCD);
+      }
+    }
+
+    /* Close */
+    fclose(fpZip);
+    fclose(fpOut);
+
+    /* Wipe temporary file */
+    (void)remove(fileOutTmp);
+
+    /* Number of recovered entries */
+    if (err == Z_OK) {
+      if (nRecovered != NULL) {
+        *nRecovered = entries;
+      }
+      if (bytesRecovered != NULL) {
+        *bytesRecovered = totalBytes;
+      }
+    }
+  } else {
+    err = Z_STREAM_ERROR;
+  }
+  return err;
+}
diff --git a/xs/src/png/zlib/contrib/minizip/mztools.h b/xs/src/png/zlib/contrib/minizip/mztools.h
new file mode 100644
index 000000000..a49a426ec
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/mztools.h
@@ -0,0 +1,37 @@
+/*
+  Additional tools for Minizip
+  Code: Xavier Roche '2004
+  License: Same as ZLIB (www.gzip.org)
+*/
+
+#ifndef _zip_tools_H
+#define _zip_tools_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef _ZLIB_H
+#include "zlib.h"
+#endif
+
+#include "unzip.h"
+
+/* Repair a ZIP file (missing central directory)
+   file: file to recover
+   fileOut: output file after recovery
+   fileOutTmp: temporary file name used for recovery
+*/
+extern int ZEXPORT unzRepair(const char* file,
+                             const char* fileOut,
+                             const char* fileOutTmp,
+                             uLong* nRecovered,
+                             uLong* bytesRecovered);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
diff --git a/xs/src/png/zlib/contrib/minizip/unzip.c b/xs/src/png/zlib/contrib/minizip/unzip.c
new file mode 100644
index 000000000..bcfb9416e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/unzip.c
@@ -0,0 +1,2125 @@
+/* unzip.c -- IO for uncompress .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+
+  ------------------------------------------------------------------------------------
+  Decryption code comes from crypt.c by Info-ZIP but has been greatly reduced in terms of
+  compatibility with older software. The following is from the original crypt.c.
+  Code woven in by Terry Thorsen 1/2003.
+
+  Copyright (c) 1990-2000 Info-ZIP.  All rights reserved.
+
+  See the accompanying file LICENSE, version 2000-Apr-09 or later
+  (the contents of which are also included in zip.h) for terms of use.
+  If, for some reason, all these files are missing, the Info-ZIP license
+  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
+
+        crypt.c (full version) by Info-ZIP.      Last revised:  [see crypt.h]
+
+  The encryption/decryption parts of this source code (as opposed to the
+  non-echoing password parts) were originally written in Europe.  The
+  whole source package can be freely distributed, including from the USA.
+  (Prior to January 2000, re-export from the US was a violation of US law.)
+
+        This encryption code is a direct transcription of the algorithm from
+  Roger Schlafly, described by Phil Katz in the file appnote.txt.  This
+  file (appnote.txt) is distributed with the PKZIP program (even in the
+  version without encryption capabilities).
+
+        ------------------------------------------------------------------------------------
+
+        Changes in unzip.c
+
+        2007-2008 - Even Rouault - Addition of cpl_unzGetCurrentFileZStreamPos
+  2007-2008 - Even Rouault - Decoration of symbol names unz* -> cpl_unz*
+  2007-2008 - Even Rouault - Remove old C style function prototypes
+  2007-2008 - Even Rouault - Add unzip support for ZIP64
+
+        Copyright (C) 2007-2008 Even Rouault
+
+
+        Oct-2009 - Mathias Svensson - Removed cpl_* from symbol names (Even Rouault added them but since this is now moved to a new project (minizip64) I renamed them again).
+  Oct-2009 - Mathias Svensson - Fixed problem if uncompressed size was > 4G and compressed size was <4G
+                                should only read the compressed/uncompressed size from the Zip64 format if
+                                the size from normal header was 0xFFFFFFFF
+  Oct-2009 - Mathias Svensson - Applied some bug fixes from paches recived from Gilles Vollant
+        Oct-2009 - Mathias Svensson - Applied support to unzip files with compression mathod BZIP2 (bzip2 lib is required)
+                                Patch created by Daniel Borca
+
+  Jan-2010 - back to unzip and minizip 1.0 name scheme, with compatibility layer
+
+  Copyright (C) 1998 - 2010 Gilles Vollant, Even Rouault, Mathias Svensson
+
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef NOUNCRYPT
+        #define NOUNCRYPT
+#endif
+
+#include "zlib.h"
+#include "unzip.h"
+
+#ifdef STDC
+#  include <stddef.h>
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+#ifdef NO_ERRNO_H
+    extern int errno;
+#else
+#   include <errno.h>
+#endif
+
+
+#ifndef local
+#  define local static
+#endif
+/* compile with -Dlocal if your debugger can't find static symbols */
+
+
+#ifndef CASESENSITIVITYDEFAULT_NO
+#  if !defined(unix) && !defined(CASESENSITIVITYDEFAULT_YES)
+#    define CASESENSITIVITYDEFAULT_NO
+#  endif
+#endif
+
+
+#ifndef UNZ_BUFSIZE
+#define UNZ_BUFSIZE (16384)
+#endif
+
+#ifndef UNZ_MAXFILENAMEINZIP
+#define UNZ_MAXFILENAMEINZIP (256)
+#endif
+
+#ifndef ALLOC
+# define ALLOC(size) (malloc(size))
+#endif
+#ifndef TRYFREE
+# define TRYFREE(p) {if (p) free(p);}
+#endif
+
+#define SIZECENTRALDIRITEM (0x2e)
+#define SIZEZIPLOCALHEADER (0x1e)
+
+
+const char unz_copyright[] =
+   " unzip 1.01 Copyright 1998-2004 Gilles Vollant - http://www.winimage.com/zLibDll";
+
+/* unz_file_info_interntal contain internal info about a file in zipfile*/
+typedef struct unz_file_info64_internal_s
+{
+    ZPOS64_T offset_curfile;/* relative offset of local header 8 bytes */
+} unz_file_info64_internal;
+
+
+/* file_in_zip_read_info_s contain internal information about a file in zipfile,
+    when reading and decompress it */
+typedef struct
+{
+    char  *read_buffer;         /* internal buffer for compressed data */
+    z_stream stream;            /* zLib stream structure for inflate */
+
+#ifdef HAVE_BZIP2
+    bz_stream bstream;          /* bzLib stream structure for bziped */
+#endif
+
+    ZPOS64_T pos_in_zipfile;       /* position in byte on the zipfile, for fseek*/
+    uLong stream_initialised;   /* flag set if stream structure is initialised*/
+
+    ZPOS64_T offset_local_extrafield;/* offset of the local extra field */
+    uInt  size_local_extrafield;/* size of the local extra field */
+    ZPOS64_T pos_local_extrafield;   /* position in the local extra field in read*/
+    ZPOS64_T total_out_64;
+
+    uLong crc32;                /* crc32 of all data uncompressed */
+    uLong crc32_wait;           /* crc32 we must obtain after decompress all */
+    ZPOS64_T rest_read_compressed; /* number of byte to be decompressed */
+    ZPOS64_T rest_read_uncompressed;/*number of byte to be obtained after decomp*/
+    zlib_filefunc64_32_def z_filefunc;
+    voidpf filestream;        /* io structore of the zipfile */
+    uLong compression_method;   /* compression method (0==store) */
+    ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
+    int   raw;
+} file_in_zip64_read_info_s;
+
+
+/* unz64_s contain internal information about the zipfile
+*/
+typedef struct
+{
+    zlib_filefunc64_32_def z_filefunc;
+    int is64bitOpenFunction;
+    voidpf filestream;        /* io structore of the zipfile */
+    unz_global_info64 gi;       /* public global information */
+    ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
+    ZPOS64_T num_file;             /* number of the current file in the zipfile*/
+    ZPOS64_T pos_in_central_dir;   /* pos of the current file in the central dir*/
+    ZPOS64_T current_file_ok;      /* flag about the usability of the current file*/
+    ZPOS64_T central_pos;          /* position of the beginning of the central dir*/
+
+    ZPOS64_T size_central_dir;     /* size of the central directory  */
+    ZPOS64_T offset_central_dir;   /* offset of start of central directory with
+                                   respect to the starting disk number */
+
+    unz_file_info64 cur_file_info; /* public info about the current file in zip*/
+    unz_file_info64_internal cur_file_info_internal; /* private info about it*/
+    file_in_zip64_read_info_s* pfile_in_zip_read; /* structure about the current
+                                        file if we are decompressing it */
+    int encrypted;
+
+    int isZip64;
+
+#    ifndef NOUNCRYPT
+    unsigned long keys[3];     /* keys defining the pseudo-random sequence */
+    const z_crc_t* pcrc_32_tab;
+#    endif
+} unz64_s;
+
+
+#ifndef NOUNCRYPT
+#include "crypt.h"
+#endif
+
+/* ===========================================================================
+     Read a byte from a gz_stream; update next_in and avail_in. Return EOF
+   for end of file.
+   IN assertion: the stream s has been successfully opened for reading.
+*/
+
+
+local int unz64local_getByte OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    int *pi));
+
+local int unz64local_getByte(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, int *pi)
+{
+    unsigned char c;
+    int err = (int)ZREAD64(*pzlib_filefunc_def,filestream,&c,1);
+    if (err==1)
+    {
+        *pi = (int)c;
+        return UNZ_OK;
+    }
+    else
+    {
+        if (ZERROR64(*pzlib_filefunc_def,filestream))
+            return UNZ_ERRNO;
+        else
+            return UNZ_EOF;
+    }
+}
+
+
+/* ===========================================================================
+   Reads a long in LSB order from the given gz_stream. Sets
+*/
+local int unz64local_getShort OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    uLong *pX));
+
+local int unz64local_getShort (const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                             voidpf filestream,
+                             uLong *pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((uLong)i)<<8;
+
+    if (err==UNZ_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int unz64local_getLong OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    uLong *pX));
+
+local int unz64local_getLong (const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                            voidpf filestream,
+                            uLong *pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((uLong)i)<<8;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((uLong)i)<<16;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<24;
+
+    if (err==UNZ_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int unz64local_getLong64 OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    ZPOS64_T *pX));
+
+
+local int unz64local_getLong64 (const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                            voidpf filestream,
+                            ZPOS64_T *pX)
+{
+    ZPOS64_T x ;
+    int i = 0;
+    int err;
+
+    err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (ZPOS64_T)i;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<8;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<16;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<24;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<32;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<40;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<48;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<56;
+
+    if (err==UNZ_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+/* My own strcmpi / strcasecmp */
+local int strcmpcasenosensitive_internal (const char* fileName1, const char* fileName2)
+{
+    for (;;)
+    {
+        char c1=*(fileName1++);
+        char c2=*(fileName2++);
+        if ((c1>='a') && (c1<='z'))
+            c1 -= 0x20;
+        if ((c2>='a') && (c2<='z'))
+            c2 -= 0x20;
+        if (c1=='\0')
+            return ((c2=='\0') ? 0 : -1);
+        if (c2=='\0')
+            return 1;
+        if (c1<c2)
+            return -1;
+        if (c1>c2)
+            return 1;
+    }
+}
+
+
+#ifdef  CASESENSITIVITYDEFAULT_NO
+#define CASESENSITIVITYDEFAULTVALUE 2
+#else
+#define CASESENSITIVITYDEFAULTVALUE 1
+#endif
+
+#ifndef STRCMPCASENOSENTIVEFUNCTION
+#define STRCMPCASENOSENTIVEFUNCTION strcmpcasenosensitive_internal
+#endif
+
+/*
+   Compare two filename (fileName1,fileName2).
+   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
+   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
+                                                                or strcasecmp)
+   If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
+        (like 1 on Unix, 2 on Windows)
+
+*/
+extern int ZEXPORT unzStringFileNameCompare (const char*  fileName1,
+                                                 const char*  fileName2,
+                                                 int iCaseSensitivity)
+
+{
+    if (iCaseSensitivity==0)
+        iCaseSensitivity=CASESENSITIVITYDEFAULTVALUE;
+
+    if (iCaseSensitivity==1)
+        return strcmp(fileName1,fileName2);
+
+    return STRCMPCASENOSENTIVEFUNCTION(fileName1,fileName2);
+}
+
+#ifndef BUFREADCOMMENT
+#define BUFREADCOMMENT (0x400)
+#endif
+
+/*
+  Locate the Central directory of a zipfile (at the end, just before
+    the global comment)
+*/
+local ZPOS64_T unz64local_SearchCentralDir OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream));
+local ZPOS64_T unz64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream)
+{
+    unsigned char* buf;
+    ZPOS64_T uSizeFile;
+    ZPOS64_T uBackRead;
+    ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+    ZPOS64_T uPosFound=0;
+
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+        return 0;
+
+
+    uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+    if (uMaxBack>uSizeFile)
+        uMaxBack = uSizeFile;
+
+    buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+    if (buf==NULL)
+        return 0;
+
+    uBackRead = 4;
+    while (uBackRead<uMaxBack)
+    {
+        uLong uReadSize;
+        ZPOS64_T uReadPos ;
+        int i;
+        if (uBackRead+BUFREADCOMMENT>uMaxBack)
+            uBackRead = uMaxBack;
+        else
+            uBackRead+=BUFREADCOMMENT;
+        uReadPos = uSizeFile-uBackRead ;
+
+        uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+                     (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+        if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            break;
+
+        if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+            break;
+
+        for (i=(int)uReadSize-3; (i--)>0;)
+            if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) &&
+                ((*(buf+i+2))==0x05) && ((*(buf+i+3))==0x06))
+            {
+                uPosFound = uReadPos+i;
+                break;
+            }
+
+        if (uPosFound!=0)
+            break;
+    }
+    TRYFREE(buf);
+    return uPosFound;
+}
+
+
+/*
+  Locate the Central directory 64 of a zipfile (at the end, just before
+    the global comment)
+*/
+local ZPOS64_T unz64local_SearchCentralDir64 OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream));
+
+local ZPOS64_T unz64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                                      voidpf filestream)
+{
+    unsigned char* buf;
+    ZPOS64_T uSizeFile;
+    ZPOS64_T uBackRead;
+    ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+    ZPOS64_T uPosFound=0;
+    uLong uL;
+                ZPOS64_T relativeOffset;
+
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+        return 0;
+
+
+    uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+    if (uMaxBack>uSizeFile)
+        uMaxBack = uSizeFile;
+
+    buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+    if (buf==NULL)
+        return 0;
+
+    uBackRead = 4;
+    while (uBackRead<uMaxBack)
+    {
+        uLong uReadSize;
+        ZPOS64_T uReadPos;
+        int i;
+        if (uBackRead+BUFREADCOMMENT>uMaxBack)
+            uBackRead = uMaxBack;
+        else
+            uBackRead+=BUFREADCOMMENT;
+        uReadPos = uSizeFile-uBackRead ;
+
+        uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+                     (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+        if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            break;
+
+        if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+            break;
+
+        for (i=(int)uReadSize-3; (i--)>0;)
+            if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) &&
+                ((*(buf+i+2))==0x06) && ((*(buf+i+3))==0x07))
+            {
+                uPosFound = uReadPos+i;
+                break;
+            }
+
+        if (uPosFound!=0)
+            break;
+    }
+    TRYFREE(buf);
+    if (uPosFound == 0)
+        return 0;
+
+    /* Zip64 end of central directory locator */
+    if (ZSEEK64(*pzlib_filefunc_def,filestream, uPosFound,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return 0;
+
+    /* the signature, already checked */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+
+    /* number of the disk with the start of the zip64 end of  central directory */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+    if (uL != 0)
+        return 0;
+
+    /* relative offset of the zip64 end of central directory record */
+    if (unz64local_getLong64(pzlib_filefunc_def,filestream,&relativeOffset)!=UNZ_OK)
+        return 0;
+
+    /* total number of disks */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+    if (uL != 1)
+        return 0;
+
+    /* Goto end of central directory record */
+    if (ZSEEK64(*pzlib_filefunc_def,filestream, relativeOffset,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return 0;
+
+     /* the signature */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+
+    if (uL != 0x06064b50)
+        return 0;
+
+    return relativeOffset;
+}
+
+/*
+  Open a Zip file. path contain the full pathname (by example,
+     on a Windows NT computer "c:\\test\\zlib114.zip" or on an Unix computer
+     "zlib/zlib114.zip".
+     If the zipfile cannot be opened (file doesn't exist or in not valid), the
+       return value is NULL.
+     Else, the return value is a unzFile Handle, usable with other function
+       of this unzip package.
+*/
+local unzFile unzOpenInternal (const void *path,
+                               zlib_filefunc64_32_def* pzlib_filefunc64_32_def,
+                               int is64bitOpenFunction)
+{
+    unz64_s us;
+    unz64_s *s;
+    ZPOS64_T central_pos;
+    uLong   uL;
+
+    uLong number_disk;          /* number of the current dist, used for
+                                   spaning ZIP, unsupported, always 0*/
+    uLong number_disk_with_CD;  /* number the the disk with central dir, used
+                                   for spaning ZIP, unsupported, always 0*/
+    ZPOS64_T number_entry_CD;      /* total number of entries in
+                                   the central dir
+                                   (same than number_entry on nospan) */
+
+    int err=UNZ_OK;
+
+    if (unz_copyright[0]!=' ')
+        return NULL;
+
+    us.z_filefunc.zseek32_file = NULL;
+    us.z_filefunc.ztell32_file = NULL;
+    if (pzlib_filefunc64_32_def==NULL)
+        fill_fopen64_filefunc(&us.z_filefunc.zfile_func64);
+    else
+        us.z_filefunc = *pzlib_filefunc64_32_def;
+    us.is64bitOpenFunction = is64bitOpenFunction;
+
+
+
+    us.filestream = ZOPEN64(us.z_filefunc,
+                                                 path,
+                                                 ZLIB_FILEFUNC_MODE_READ |
+                                                 ZLIB_FILEFUNC_MODE_EXISTING);
+    if (us.filestream==NULL)
+        return NULL;
+
+    central_pos = unz64local_SearchCentralDir64(&us.z_filefunc,us.filestream);
+    if (central_pos)
+    {
+        uLong uS;
+        ZPOS64_T uL64;
+
+        us.isZip64 = 1;
+
+        if (ZSEEK64(us.z_filefunc, us.filestream,
+                                      central_pos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        err=UNZ_ERRNO;
+
+        /* the signature, already checked */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* size of zip64 end of central directory record */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&uL64)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* version made by */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uS)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* version needed to extract */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uS)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of this disk */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&number_disk)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of the disk with the start of the central directory */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&number_disk_with_CD)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* total number of entries in the central directory on this disk */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&us.gi.number_entry)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* total number of entries in the central directory */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&number_entry_CD)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        if ((number_entry_CD!=us.gi.number_entry) ||
+            (number_disk_with_CD!=0) ||
+            (number_disk!=0))
+            err=UNZ_BADZIPFILE;
+
+        /* size of the central directory */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&us.size_central_dir)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* offset of start of central directory with respect to the
+          starting disk number */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&us.offset_central_dir)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        us.gi.size_comment = 0;
+    }
+    else
+    {
+        central_pos = unz64local_SearchCentralDir(&us.z_filefunc,us.filestream);
+        if (central_pos==0)
+            err=UNZ_ERRNO;
+
+        us.isZip64 = 0;
+
+        if (ZSEEK64(us.z_filefunc, us.filestream,
+                                        central_pos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            err=UNZ_ERRNO;
+
+        /* the signature, already checked */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of this disk */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&number_disk)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of the disk with the start of the central directory */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&number_disk_with_CD)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* total number of entries in the central dir on this disk */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        us.gi.number_entry = uL;
+
+        /* total number of entries in the central dir */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        number_entry_CD = uL;
+
+        if ((number_entry_CD!=us.gi.number_entry) ||
+            (number_disk_with_CD!=0) ||
+            (number_disk!=0))
+            err=UNZ_BADZIPFILE;
+
+        /* size of the central directory */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        us.size_central_dir = uL;
+
+        /* offset of start of central directory with respect to the
+            starting disk number */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        us.offset_central_dir = uL;
+
+        /* zipfile comment length */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&us.gi.size_comment)!=UNZ_OK)
+            err=UNZ_ERRNO;
+    }
+
+    if ((central_pos<us.offset_central_dir+us.size_central_dir) &&
+        (err==UNZ_OK))
+        err=UNZ_BADZIPFILE;
+
+    if (err!=UNZ_OK)
+    {
+        ZCLOSE64(us.z_filefunc, us.filestream);
+        return NULL;
+    }
+
+    us.byte_before_the_zipfile = central_pos -
+                            (us.offset_central_dir+us.size_central_dir);
+    us.central_pos = central_pos;
+    us.pfile_in_zip_read = NULL;
+    us.encrypted = 0;
+
+
+    s=(unz64_s*)ALLOC(sizeof(unz64_s));
+    if( s != NULL)
+    {
+        *s=us;
+        unzGoToFirstFile((unzFile)s);
+    }
+    return (unzFile)s;
+}
+
+
+extern unzFile ZEXPORT unzOpen2 (const char *path,
+                                        zlib_filefunc_def* pzlib_filefunc32_def)
+{
+    if (pzlib_filefunc32_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        fill_zlib_filefunc64_32_def_from_filefunc32(&zlib_filefunc64_32_def_fill,pzlib_filefunc32_def);
+        return unzOpenInternal(path, &zlib_filefunc64_32_def_fill, 0);
+    }
+    else
+        return unzOpenInternal(path, NULL, 0);
+}
+
+extern unzFile ZEXPORT unzOpen2_64 (const void *path,
+                                     zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    if (pzlib_filefunc_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        zlib_filefunc64_32_def_fill.zfile_func64 = *pzlib_filefunc_def;
+        zlib_filefunc64_32_def_fill.ztell32_file = NULL;
+        zlib_filefunc64_32_def_fill.zseek32_file = NULL;
+        return unzOpenInternal(path, &zlib_filefunc64_32_def_fill, 1);
+    }
+    else
+        return unzOpenInternal(path, NULL, 1);
+}
+
+extern unzFile ZEXPORT unzOpen (const char *path)
+{
+    return unzOpenInternal(path, NULL, 0);
+}
+
+extern unzFile ZEXPORT unzOpen64 (const void *path)
+{
+    return unzOpenInternal(path, NULL, 1);
+}
+
+/*
+  Close a ZipFile opened with unzOpen.
+  If there is files inside the .Zip opened with unzOpenCurrentFile (see later),
+    these files MUST be closed with unzCloseCurrentFile before call unzClose.
+  return UNZ_OK if there is no problem. */
+extern int ZEXPORT unzClose (unzFile file)
+{
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    if (s->pfile_in_zip_read!=NULL)
+        unzCloseCurrentFile(file);
+
+    ZCLOSE64(s->z_filefunc, s->filestream);
+    TRYFREE(s);
+    return UNZ_OK;
+}
+
+
+/*
+  Write info about the ZipFile in the *pglobal_info structure.
+  No preparation of the structure is needed
+  return UNZ_OK if there is no problem. */
+extern int ZEXPORT unzGetGlobalInfo64 (unzFile file, unz_global_info64* pglobal_info)
+{
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    *pglobal_info=s->gi;
+    return UNZ_OK;
+}
+
+extern int ZEXPORT unzGetGlobalInfo (unzFile file, unz_global_info* pglobal_info32)
+{
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    /* to do : check if number_entry is not truncated */
+    pglobal_info32->number_entry = (uLong)s->gi.number_entry;
+    pglobal_info32->size_comment = s->gi.size_comment;
+    return UNZ_OK;
+}
+/*
+   Translate date/time from Dos format to tm_unz (readable more easilty)
+*/
+local void unz64local_DosDateToTmuDate (ZPOS64_T ulDosDate, tm_unz* ptm)
+{
+    ZPOS64_T uDate;
+    uDate = (ZPOS64_T)(ulDosDate>>16);
+    ptm->tm_mday = (uInt)(uDate&0x1f) ;
+    ptm->tm_mon =  (uInt)((((uDate)&0x1E0)/0x20)-1) ;
+    ptm->tm_year = (uInt)(((uDate&0x0FE00)/0x0200)+1980) ;
+
+    ptm->tm_hour = (uInt) ((ulDosDate &0xF800)/0x800);
+    ptm->tm_min =  (uInt) ((ulDosDate&0x7E0)/0x20) ;
+    ptm->tm_sec =  (uInt) (2*(ulDosDate&0x1f)) ;
+}
+
+/*
+  Get Info about the current file in the zipfile, with internal only info
+*/
+local int unz64local_GetCurrentFileInfoInternal OF((unzFile file,
+                                                  unz_file_info64 *pfile_info,
+                                                  unz_file_info64_internal
+                                                  *pfile_info_internal,
+                                                  char *szFileName,
+                                                  uLong fileNameBufferSize,
+                                                  void *extraField,
+                                                  uLong extraFieldBufferSize,
+                                                  char *szComment,
+                                                  uLong commentBufferSize));
+
+local int unz64local_GetCurrentFileInfoInternal (unzFile file,
+                                                  unz_file_info64 *pfile_info,
+                                                  unz_file_info64_internal
+                                                  *pfile_info_internal,
+                                                  char *szFileName,
+                                                  uLong fileNameBufferSize,
+                                                  void *extraField,
+                                                  uLong extraFieldBufferSize,
+                                                  char *szComment,
+                                                  uLong commentBufferSize)
+{
+    unz64_s* s;
+    unz_file_info64 file_info;
+    unz_file_info64_internal file_info_internal;
+    int err=UNZ_OK;
+    uLong uMagic;
+    long lSeek=0;
+    uLong uL;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (ZSEEK64(s->z_filefunc, s->filestream,
+              s->pos_in_central_dir+s->byte_before_the_zipfile,
+              ZLIB_FILEFUNC_SEEK_SET)!=0)
+        err=UNZ_ERRNO;
+
+
+    /* we check the magic */
+    if (err==UNZ_OK)
+    {
+        if (unz64local_getLong(&s->z_filefunc, s->filestream,&uMagic) != UNZ_OK)
+            err=UNZ_ERRNO;
+        else if (uMagic!=0x02014b50)
+            err=UNZ_BADZIPFILE;
+    }
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.version) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.version_needed) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.flag) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.compression_method) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&file_info.dosDate) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    unz64local_DosDateToTmuDate(file_info.dosDate,&file_info.tmu_date);
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&file_info.crc) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+        err=UNZ_ERRNO;
+    file_info.compressed_size = uL;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+        err=UNZ_ERRNO;
+    file_info.uncompressed_size = uL;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.size_filename) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.size_file_extra) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.size_file_comment) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.disk_num_start) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.internal_fa) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&file_info.external_fa) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+                // relative offset of local header
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+        err=UNZ_ERRNO;
+    file_info_internal.offset_curfile = uL;
+
+    lSeek+=file_info.size_filename;
+    if ((err==UNZ_OK) && (szFileName!=NULL))
+    {
+        uLong uSizeRead ;
+        if (file_info.size_filename<fileNameBufferSize)
+        {
+            *(szFileName+file_info.size_filename)='\0';
+            uSizeRead = file_info.size_filename;
+        }
+        else
+            uSizeRead = fileNameBufferSize;
+
+        if ((file_info.size_filename>0) && (fileNameBufferSize>0))
+            if (ZREAD64(s->z_filefunc, s->filestream,szFileName,uSizeRead)!=uSizeRead)
+                err=UNZ_ERRNO;
+        lSeek -= uSizeRead;
+    }
+
+    // Read extrafield
+    if ((err==UNZ_OK) && (extraField!=NULL))
+    {
+        ZPOS64_T uSizeRead ;
+        if (file_info.size_file_extra<extraFieldBufferSize)
+            uSizeRead = file_info.size_file_extra;
+        else
+            uSizeRead = extraFieldBufferSize;
+
+        if (lSeek!=0)
+        {
+            if (ZSEEK64(s->z_filefunc, s->filestream,lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                lSeek=0;
+            else
+                err=UNZ_ERRNO;
+        }
+
+        if ((file_info.size_file_extra>0) && (extraFieldBufferSize>0))
+            if (ZREAD64(s->z_filefunc, s->filestream,extraField,(uLong)uSizeRead)!=uSizeRead)
+                err=UNZ_ERRNO;
+
+        lSeek += file_info.size_file_extra - (uLong)uSizeRead;
+    }
+    else
+        lSeek += file_info.size_file_extra;
+
+
+    if ((err==UNZ_OK) && (file_info.size_file_extra != 0))
+    {
+                                uLong acc = 0;
+
+        // since lSeek now points to after the extra field we need to move back
+        lSeek -= file_info.size_file_extra;
+
+        if (lSeek!=0)
+        {
+            if (ZSEEK64(s->z_filefunc, s->filestream,lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                lSeek=0;
+            else
+                err=UNZ_ERRNO;
+        }
+
+        while(acc < file_info.size_file_extra)
+        {
+            uLong headerId;
+                                                uLong dataSize;
+
+            if (unz64local_getShort(&s->z_filefunc, s->filestream,&headerId) != UNZ_OK)
+                err=UNZ_ERRNO;
+
+            if (unz64local_getShort(&s->z_filefunc, s->filestream,&dataSize) != UNZ_OK)
+                err=UNZ_ERRNO;
+
+            /* ZIP64 extra fields */
+            if (headerId == 0x0001)
+            {
+                                                        uLong uL;
+
+                                                                if(file_info.uncompressed_size == MAXU32)
+                                                                {
+                                                                        if (unz64local_getLong64(&s->z_filefunc, s->filestream,&file_info.uncompressed_size) != UNZ_OK)
+                                                                                        err=UNZ_ERRNO;
+                                                                }
+
+                                                                if(file_info.compressed_size == MAXU32)
+                                                                {
+                                                                        if (unz64local_getLong64(&s->z_filefunc, s->filestream,&file_info.compressed_size) != UNZ_OK)
+                                                                                  err=UNZ_ERRNO;
+                                                                }
+
+                                                                if(file_info_internal.offset_curfile == MAXU32)
+                                                                {
+                                                                        /* Relative Header offset */
+                                                                        if (unz64local_getLong64(&s->z_filefunc, s->filestream,&file_info_internal.offset_curfile) != UNZ_OK)
+                                                                                err=UNZ_ERRNO;
+                                                                }
+
+                                                                if(file_info.disk_num_start == MAXU32)
+                                                                {
+                                                                        /* Disk Start Number */
+                                                                        if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+                                                                                err=UNZ_ERRNO;
+                                                                }
+
+            }
+            else
+            {
+                if (ZSEEK64(s->z_filefunc, s->filestream,dataSize,ZLIB_FILEFUNC_SEEK_CUR)!=0)
+                    err=UNZ_ERRNO;
+            }
+
+            acc += 2 + 2 + dataSize;
+        }
+    }
+
+    if ((err==UNZ_OK) && (szComment!=NULL))
+    {
+        uLong uSizeRead ;
+        if (file_info.size_file_comment<commentBufferSize)
+        {
+            *(szComment+file_info.size_file_comment)='\0';
+            uSizeRead = file_info.size_file_comment;
+        }
+        else
+            uSizeRead = commentBufferSize;
+
+        if (lSeek!=0)
+        {
+            if (ZSEEK64(s->z_filefunc, s->filestream,lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                lSeek=0;
+            else
+                err=UNZ_ERRNO;
+        }
+
+        if ((file_info.size_file_comment>0) && (commentBufferSize>0))
+            if (ZREAD64(s->z_filefunc, s->filestream,szComment,uSizeRead)!=uSizeRead)
+                err=UNZ_ERRNO;
+        lSeek+=file_info.size_file_comment - uSizeRead;
+    }
+    else
+        lSeek+=file_info.size_file_comment;
+
+
+    if ((err==UNZ_OK) && (pfile_info!=NULL))
+        *pfile_info=file_info;
+
+    if ((err==UNZ_OK) && (pfile_info_internal!=NULL))
+        *pfile_info_internal=file_info_internal;
+
+    return err;
+}
+
+
+
+/*
+  Write info about the ZipFile in the *pglobal_info structure.
+  No preparation of the structure is needed
+  return UNZ_OK if there is no problem.
+*/
+extern int ZEXPORT unzGetCurrentFileInfo64 (unzFile file,
+                                          unz_file_info64 * pfile_info,
+                                          char * szFileName, uLong fileNameBufferSize,
+                                          void *extraField, uLong extraFieldBufferSize,
+                                          char* szComment,  uLong commentBufferSize)
+{
+    return unz64local_GetCurrentFileInfoInternal(file,pfile_info,NULL,
+                                                szFileName,fileNameBufferSize,
+                                                extraField,extraFieldBufferSize,
+                                                szComment,commentBufferSize);
+}
+
+extern int ZEXPORT unzGetCurrentFileInfo (unzFile file,
+                                          unz_file_info * pfile_info,
+                                          char * szFileName, uLong fileNameBufferSize,
+                                          void *extraField, uLong extraFieldBufferSize,
+                                          char* szComment,  uLong commentBufferSize)
+{
+    int err;
+    unz_file_info64 file_info64;
+    err = unz64local_GetCurrentFileInfoInternal(file,&file_info64,NULL,
+                                                szFileName,fileNameBufferSize,
+                                                extraField,extraFieldBufferSize,
+                                                szComment,commentBufferSize);
+    if ((err==UNZ_OK) && (pfile_info != NULL))
+    {
+        pfile_info->version = file_info64.version;
+        pfile_info->version_needed = file_info64.version_needed;
+        pfile_info->flag = file_info64.flag;
+        pfile_info->compression_method = file_info64.compression_method;
+        pfile_info->dosDate = file_info64.dosDate;
+        pfile_info->crc = file_info64.crc;
+
+        pfile_info->size_filename = file_info64.size_filename;
+        pfile_info->size_file_extra = file_info64.size_file_extra;
+        pfile_info->size_file_comment = file_info64.size_file_comment;
+
+        pfile_info->disk_num_start = file_info64.disk_num_start;
+        pfile_info->internal_fa = file_info64.internal_fa;
+        pfile_info->external_fa = file_info64.external_fa;
+
+        pfile_info->tmu_date = file_info64.tmu_date,
+
+
+        pfile_info->compressed_size = (uLong)file_info64.compressed_size;
+        pfile_info->uncompressed_size = (uLong)file_info64.uncompressed_size;
+
+    }
+    return err;
+}
+/*
+  Set the current file of the zipfile to the first file.
+  return UNZ_OK if there is no problem
+*/
+extern int ZEXPORT unzGoToFirstFile (unzFile file)
+{
+    int err=UNZ_OK;
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    s->pos_in_central_dir=s->offset_central_dir;
+    s->num_file=0;
+    err=unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                             &s->cur_file_info_internal,
+                                             NULL,0,NULL,0,NULL,0);
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+/*
+  Set the current file of the zipfile to the next file.
+  return UNZ_OK if there is no problem
+  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
+*/
+extern int ZEXPORT unzGoToNextFile (unzFile  file)
+{
+    unz64_s* s;
+    int err;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_END_OF_LIST_OF_FILE;
+    if (s->gi.number_entry != 0xffff)    /* 2^16 files overflow hack */
+      if (s->num_file+1==s->gi.number_entry)
+        return UNZ_END_OF_LIST_OF_FILE;
+
+    s->pos_in_central_dir += SIZECENTRALDIRITEM + s->cur_file_info.size_filename +
+            s->cur_file_info.size_file_extra + s->cur_file_info.size_file_comment ;
+    s->num_file++;
+    err = unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                               &s->cur_file_info_internal,
+                                               NULL,0,NULL,0,NULL,0);
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+
+/*
+  Try locate the file szFileName in the zipfile.
+  For the iCaseSensitivity signification, see unzStringFileNameCompare
+
+  return value :
+  UNZ_OK if the file is found. It becomes the current file.
+  UNZ_END_OF_LIST_OF_FILE if the file is not found
+*/
+extern int ZEXPORT unzLocateFile (unzFile file, const char *szFileName, int iCaseSensitivity)
+{
+    unz64_s* s;
+    int err;
+
+    /* We remember the 'current' position in the file so that we can jump
+     * back there if we fail.
+     */
+    unz_file_info64 cur_file_infoSaved;
+    unz_file_info64_internal cur_file_info_internalSaved;
+    ZPOS64_T num_fileSaved;
+    ZPOS64_T pos_in_central_dirSaved;
+
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+
+    if (strlen(szFileName)>=UNZ_MAXFILENAMEINZIP)
+        return UNZ_PARAMERROR;
+
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_END_OF_LIST_OF_FILE;
+
+    /* Save the current state */
+    num_fileSaved = s->num_file;
+    pos_in_central_dirSaved = s->pos_in_central_dir;
+    cur_file_infoSaved = s->cur_file_info;
+    cur_file_info_internalSaved = s->cur_file_info_internal;
+
+    err = unzGoToFirstFile(file);
+
+    while (err == UNZ_OK)
+    {
+        char szCurrentFileName[UNZ_MAXFILENAMEINZIP+1];
+        err = unzGetCurrentFileInfo64(file,NULL,
+                                    szCurrentFileName,sizeof(szCurrentFileName)-1,
+                                    NULL,0,NULL,0);
+        if (err == UNZ_OK)
+        {
+            if (unzStringFileNameCompare(szCurrentFileName,
+                                            szFileName,iCaseSensitivity)==0)
+                return UNZ_OK;
+            err = unzGoToNextFile(file);
+        }
+    }
+
+    /* We failed, so restore the state of the 'current file' to where we
+     * were.
+     */
+    s->num_file = num_fileSaved ;
+    s->pos_in_central_dir = pos_in_central_dirSaved ;
+    s->cur_file_info = cur_file_infoSaved;
+    s->cur_file_info_internal = cur_file_info_internalSaved;
+    return err;
+}
+
+
+/*
+///////////////////////////////////////////
+// Contributed by Ryan Haksi (mailto://cryogen@infoserve.net)
+// I need random access
+//
+// Further optimization could be realized by adding an ability
+// to cache the directory in memory. The goal being a single
+// comprehensive file read to put the file I need in a memory.
+*/
+
+/*
+typedef struct unz_file_pos_s
+{
+    ZPOS64_T pos_in_zip_directory;   // offset in file
+    ZPOS64_T num_of_file;            // # of file
+} unz_file_pos;
+*/
+
+extern int ZEXPORT unzGetFilePos64(unzFile file, unz64_file_pos*  file_pos)
+{
+    unz64_s* s;
+
+    if (file==NULL || file_pos==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_END_OF_LIST_OF_FILE;
+
+    file_pos->pos_in_zip_directory  = s->pos_in_central_dir;
+    file_pos->num_of_file           = s->num_file;
+
+    return UNZ_OK;
+}
+
+extern int ZEXPORT unzGetFilePos(
+    unzFile file,
+    unz_file_pos* file_pos)
+{
+    unz64_file_pos file_pos64;
+    int err = unzGetFilePos64(file,&file_pos64);
+    if (err==UNZ_OK)
+    {
+        file_pos->pos_in_zip_directory = (uLong)file_pos64.pos_in_zip_directory;
+        file_pos->num_of_file = (uLong)file_pos64.num_of_file;
+    }
+    return err;
+}
+
+extern int ZEXPORT unzGoToFilePos64(unzFile file, const unz64_file_pos* file_pos)
+{
+    unz64_s* s;
+    int err;
+
+    if (file==NULL || file_pos==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    /* jump to the right spot */
+    s->pos_in_central_dir = file_pos->pos_in_zip_directory;
+    s->num_file           = file_pos->num_of_file;
+
+    /* set the current file */
+    err = unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                               &s->cur_file_info_internal,
+                                               NULL,0,NULL,0,NULL,0);
+    /* return results */
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+extern int ZEXPORT unzGoToFilePos(
+    unzFile file,
+    unz_file_pos* file_pos)
+{
+    unz64_file_pos file_pos64;
+    if (file_pos == NULL)
+        return UNZ_PARAMERROR;
+
+    file_pos64.pos_in_zip_directory = file_pos->pos_in_zip_directory;
+    file_pos64.num_of_file = file_pos->num_of_file;
+    return unzGoToFilePos64(file,&file_pos64);
+}
+
+/*
+// Unzip Helper Functions - should be here?
+///////////////////////////////////////////
+*/
+
+/*
+  Read the local header of the current zipfile
+  Check the coherency of the local header and info in the end of central
+        directory about this file
+  store in *piSizeVar the size of extra info in local header
+        (filename and size of extra field data)
+*/
+local int unz64local_CheckCurrentFileCoherencyHeader (unz64_s* s, uInt* piSizeVar,
+                                                    ZPOS64_T * poffset_local_extrafield,
+                                                    uInt  * psize_local_extrafield)
+{
+    uLong uMagic,uData,uFlags;
+    uLong size_filename;
+    uLong size_extra_field;
+    int err=UNZ_OK;
+
+    *piSizeVar = 0;
+    *poffset_local_extrafield = 0;
+    *psize_local_extrafield = 0;
+
+    if (ZSEEK64(s->z_filefunc, s->filestream,s->cur_file_info_internal.offset_curfile +
+                                s->byte_before_the_zipfile,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return UNZ_ERRNO;
+
+
+    if (err==UNZ_OK)
+    {
+        if (unz64local_getLong(&s->z_filefunc, s->filestream,&uMagic) != UNZ_OK)
+            err=UNZ_ERRNO;
+        else if (uMagic!=0x04034b50)
+            err=UNZ_BADZIPFILE;
+    }
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&uData) != UNZ_OK)
+        err=UNZ_ERRNO;
+/*
+    else if ((err==UNZ_OK) && (uData!=s->cur_file_info.wVersion))
+        err=UNZ_BADZIPFILE;
+*/
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&uFlags) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&uData) != UNZ_OK)
+        err=UNZ_ERRNO;
+    else if ((err==UNZ_OK) && (uData!=s->cur_file_info.compression_method))
+        err=UNZ_BADZIPFILE;
+
+    if ((err==UNZ_OK) && (s->cur_file_info.compression_method!=0) &&
+/* #ifdef HAVE_BZIP2 */
+                         (s->cur_file_info.compression_method!=Z_BZIP2ED) &&
+/* #endif */
+                         (s->cur_file_info.compression_method!=Z_DEFLATED))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* date/time */
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* crc */
+        err=UNZ_ERRNO;
+    else if ((err==UNZ_OK) && (uData!=s->cur_file_info.crc) && ((uFlags & 8)==0))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* size compr */
+        err=UNZ_ERRNO;
+    else if (uData != 0xFFFFFFFF && (err==UNZ_OK) && (uData!=s->cur_file_info.compressed_size) && ((uFlags & 8)==0))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* size uncompr */
+        err=UNZ_ERRNO;
+    else if (uData != 0xFFFFFFFF && (err==UNZ_OK) && (uData!=s->cur_file_info.uncompressed_size) && ((uFlags & 8)==0))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&size_filename) != UNZ_OK)
+        err=UNZ_ERRNO;
+    else if ((err==UNZ_OK) && (size_filename!=s->cur_file_info.size_filename))
+        err=UNZ_BADZIPFILE;
+
+    *piSizeVar += (uInt)size_filename;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&size_extra_field) != UNZ_OK)
+        err=UNZ_ERRNO;
+    *poffset_local_extrafield= s->cur_file_info_internal.offset_curfile +
+                                    SIZEZIPLOCALHEADER + size_filename;
+    *psize_local_extrafield = (uInt)size_extra_field;
+
+    *piSizeVar += (uInt)size_extra_field;
+
+    return err;
+}
+
+/*
+  Open for reading data the current file in the zipfile.
+  If there is no error and the file is opened, the return value is UNZ_OK.
+*/
+extern int ZEXPORT unzOpenCurrentFile3 (unzFile file, int* method,
+                                            int* level, int raw, const char* password)
+{
+    int err=UNZ_OK;
+    uInt iSizeVar;
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    ZPOS64_T offset_local_extrafield;  /* offset of the local extra field */
+    uInt  size_local_extrafield;    /* size of the local extra field */
+#    ifndef NOUNCRYPT
+    char source[12];
+#    else
+    if (password != NULL)
+        return UNZ_PARAMERROR;
+#    endif
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_PARAMERROR;
+
+    if (s->pfile_in_zip_read != NULL)
+        unzCloseCurrentFile(file);
+
+    if (unz64local_CheckCurrentFileCoherencyHeader(s,&iSizeVar, &offset_local_extrafield,&size_local_extrafield)!=UNZ_OK)
+        return UNZ_BADZIPFILE;
+
+    pfile_in_zip_read_info = (file_in_zip64_read_info_s*)ALLOC(sizeof(file_in_zip64_read_info_s));
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_INTERNALERROR;
+
+    pfile_in_zip_read_info->read_buffer=(char*)ALLOC(UNZ_BUFSIZE);
+    pfile_in_zip_read_info->offset_local_extrafield = offset_local_extrafield;
+    pfile_in_zip_read_info->size_local_extrafield = size_local_extrafield;
+    pfile_in_zip_read_info->pos_local_extrafield=0;
+    pfile_in_zip_read_info->raw=raw;
+
+    if (pfile_in_zip_read_info->read_buffer==NULL)
+    {
+        TRYFREE(pfile_in_zip_read_info);
+        return UNZ_INTERNALERROR;
+    }
+
+    pfile_in_zip_read_info->stream_initialised=0;
+
+    if (method!=NULL)
+        *method = (int)s->cur_file_info.compression_method;
+
+    if (level!=NULL)
+    {
+        *level = 6;
+        switch (s->cur_file_info.flag & 0x06)
+        {
+          case 6 : *level = 1; break;
+          case 4 : *level = 2; break;
+          case 2 : *level = 9; break;
+        }
+    }
+
+    if ((s->cur_file_info.compression_method!=0) &&
+/* #ifdef HAVE_BZIP2 */
+        (s->cur_file_info.compression_method!=Z_BZIP2ED) &&
+/* #endif */
+        (s->cur_file_info.compression_method!=Z_DEFLATED))
+
+        err=UNZ_BADZIPFILE;
+
+    pfile_in_zip_read_info->crc32_wait=s->cur_file_info.crc;
+    pfile_in_zip_read_info->crc32=0;
+    pfile_in_zip_read_info->total_out_64=0;
+    pfile_in_zip_read_info->compression_method = s->cur_file_info.compression_method;
+    pfile_in_zip_read_info->filestream=s->filestream;
+    pfile_in_zip_read_info->z_filefunc=s->z_filefunc;
+    pfile_in_zip_read_info->byte_before_the_zipfile=s->byte_before_the_zipfile;
+
+    pfile_in_zip_read_info->stream.total_out = 0;
+
+    if ((s->cur_file_info.compression_method==Z_BZIP2ED) && (!raw))
+    {
+#ifdef HAVE_BZIP2
+      pfile_in_zip_read_info->bstream.bzalloc = (void *(*) (void *, int, int))0;
+      pfile_in_zip_read_info->bstream.bzfree = (free_func)0;
+      pfile_in_zip_read_info->bstream.opaque = (voidpf)0;
+      pfile_in_zip_read_info->bstream.state = (voidpf)0;
+
+      pfile_in_zip_read_info->stream.zalloc = (alloc_func)0;
+      pfile_in_zip_read_info->stream.zfree = (free_func)0;
+      pfile_in_zip_read_info->stream.opaque = (voidpf)0;
+      pfile_in_zip_read_info->stream.next_in = (voidpf)0;
+      pfile_in_zip_read_info->stream.avail_in = 0;
+
+      err=BZ2_bzDecompressInit(&pfile_in_zip_read_info->bstream, 0, 0);
+      if (err == Z_OK)
+        pfile_in_zip_read_info->stream_initialised=Z_BZIP2ED;
+      else
+      {
+        TRYFREE(pfile_in_zip_read_info);
+        return err;
+      }
+#else
+      pfile_in_zip_read_info->raw=1;
+#endif
+    }
+    else if ((s->cur_file_info.compression_method==Z_DEFLATED) && (!raw))
+    {
+      pfile_in_zip_read_info->stream.zalloc = (alloc_func)0;
+      pfile_in_zip_read_info->stream.zfree = (free_func)0;
+      pfile_in_zip_read_info->stream.opaque = (voidpf)0;
+      pfile_in_zip_read_info->stream.next_in = 0;
+      pfile_in_zip_read_info->stream.avail_in = 0;
+
+      err=inflateInit2(&pfile_in_zip_read_info->stream, -MAX_WBITS);
+      if (err == Z_OK)
+        pfile_in_zip_read_info->stream_initialised=Z_DEFLATED;
+      else
+      {
+        TRYFREE(pfile_in_zip_read_info);
+        return err;
+      }
+        /* windowBits is passed < 0 to tell that there is no zlib header.
+         * Note that in this case inflate *requires* an extra "dummy" byte
+         * after the compressed stream in order to complete decompression and
+         * return Z_STREAM_END.
+         * In unzip, i don't wait absolutely Z_STREAM_END because I known the
+         * size of both compressed and uncompressed data
+         */
+    }
+    pfile_in_zip_read_info->rest_read_compressed =
+            s->cur_file_info.compressed_size ;
+    pfile_in_zip_read_info->rest_read_uncompressed =
+            s->cur_file_info.uncompressed_size ;
+
+
+    pfile_in_zip_read_info->pos_in_zipfile =
+            s->cur_file_info_internal.offset_curfile + SIZEZIPLOCALHEADER +
+              iSizeVar;
+
+    pfile_in_zip_read_info->stream.avail_in = (uInt)0;
+
+    s->pfile_in_zip_read = pfile_in_zip_read_info;
+                s->encrypted = 0;
+
+#    ifndef NOUNCRYPT
+    if (password != NULL)
+    {
+        int i;
+        s->pcrc_32_tab = get_crc_table();
+        init_keys(password,s->keys,s->pcrc_32_tab);
+        if (ZSEEK64(s->z_filefunc, s->filestream,
+                  s->pfile_in_zip_read->pos_in_zipfile +
+                     s->pfile_in_zip_read->byte_before_the_zipfile,
+                  SEEK_SET)!=0)
+            return UNZ_INTERNALERROR;
+        if(ZREAD64(s->z_filefunc, s->filestream,source, 12)<12)
+            return UNZ_INTERNALERROR;
+
+        for (i = 0; i<12; i++)
+            zdecode(s->keys,s->pcrc_32_tab,source[i]);
+
+        s->pfile_in_zip_read->pos_in_zipfile+=12;
+        s->encrypted=1;
+    }
+#    endif
+
+
+    return UNZ_OK;
+}
+
+extern int ZEXPORT unzOpenCurrentFile (unzFile file)
+{
+    return unzOpenCurrentFile3(file, NULL, NULL, 0, NULL);
+}
+
+extern int ZEXPORT unzOpenCurrentFilePassword (unzFile file, const char*  password)
+{
+    return unzOpenCurrentFile3(file, NULL, NULL, 0, password);
+}
+
+extern int ZEXPORT unzOpenCurrentFile2 (unzFile file, int* method, int* level, int raw)
+{
+    return unzOpenCurrentFile3(file, method, level, raw, NULL);
+}
+
+/** Addition for GDAL : START */
+
+extern ZPOS64_T ZEXPORT unzGetCurrentFileZStreamPos64( unzFile file)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    s=(unz64_s*)file;
+    if (file==NULL)
+        return 0; //UNZ_PARAMERROR;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+    if (pfile_in_zip_read_info==NULL)
+        return 0; //UNZ_PARAMERROR;
+    return pfile_in_zip_read_info->pos_in_zipfile +
+                         pfile_in_zip_read_info->byte_before_the_zipfile;
+}
+
+/** Addition for GDAL : END */
+
+/*
+  Read bytes from the current file.
+  buf contain buffer where data must be copied
+  len the size of buf.
+
+  return the number of byte copied if somes bytes are copied
+  return 0 if the end of file was reached
+  return <0 with error code if there is an error
+    (UNZ_ERRNO for IO error, or zLib error for uncompress error)
+*/
+extern int ZEXPORT unzReadCurrentFile  (unzFile file, voidp buf, unsigned len)
+{
+    int err=UNZ_OK;
+    uInt iRead = 0;
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+
+    if (pfile_in_zip_read_info->read_buffer == NULL)
+        return UNZ_END_OF_LIST_OF_FILE;
+    if (len==0)
+        return 0;
+
+    pfile_in_zip_read_info->stream.next_out = (Bytef*)buf;
+
+    pfile_in_zip_read_info->stream.avail_out = (uInt)len;
+
+    if ((len>pfile_in_zip_read_info->rest_read_uncompressed) &&
+        (!(pfile_in_zip_read_info->raw)))
+        pfile_in_zip_read_info->stream.avail_out =
+            (uInt)pfile_in_zip_read_info->rest_read_uncompressed;
+
+    if ((len>pfile_in_zip_read_info->rest_read_compressed+
+           pfile_in_zip_read_info->stream.avail_in) &&
+         (pfile_in_zip_read_info->raw))
+        pfile_in_zip_read_info->stream.avail_out =
+            (uInt)pfile_in_zip_read_info->rest_read_compressed+
+            pfile_in_zip_read_info->stream.avail_in;
+
+    while (pfile_in_zip_read_info->stream.avail_out>0)
+    {
+        if ((pfile_in_zip_read_info->stream.avail_in==0) &&
+            (pfile_in_zip_read_info->rest_read_compressed>0))
+        {
+            uInt uReadThis = UNZ_BUFSIZE;
+            if (pfile_in_zip_read_info->rest_read_compressed<uReadThis)
+                uReadThis = (uInt)pfile_in_zip_read_info->rest_read_compressed;
+            if (uReadThis == 0)
+                return UNZ_EOF;
+            if (ZSEEK64(pfile_in_zip_read_info->z_filefunc,
+                      pfile_in_zip_read_info->filestream,
+                      pfile_in_zip_read_info->pos_in_zipfile +
+                         pfile_in_zip_read_info->byte_before_the_zipfile,
+                         ZLIB_FILEFUNC_SEEK_SET)!=0)
+                return UNZ_ERRNO;
+            if (ZREAD64(pfile_in_zip_read_info->z_filefunc,
+                      pfile_in_zip_read_info->filestream,
+                      pfile_in_zip_read_info->read_buffer,
+                      uReadThis)!=uReadThis)
+                return UNZ_ERRNO;
+
+
+#            ifndef NOUNCRYPT
+            if(s->encrypted)
+            {
+                uInt i;
+                for(i=0;i<uReadThis;i++)
+                  pfile_in_zip_read_info->read_buffer[i] =
+                      zdecode(s->keys,s->pcrc_32_tab,
+                              pfile_in_zip_read_info->read_buffer[i]);
+            }
+#            endif
+
+
+            pfile_in_zip_read_info->pos_in_zipfile += uReadThis;
+
+            pfile_in_zip_read_info->rest_read_compressed-=uReadThis;
+
+            pfile_in_zip_read_info->stream.next_in =
+                (Bytef*)pfile_in_zip_read_info->read_buffer;
+            pfile_in_zip_read_info->stream.avail_in = (uInt)uReadThis;
+        }
+
+        if ((pfile_in_zip_read_info->compression_method==0) || (pfile_in_zip_read_info->raw))
+        {
+            uInt uDoCopy,i ;
+
+            if ((pfile_in_zip_read_info->stream.avail_in == 0) &&
+                (pfile_in_zip_read_info->rest_read_compressed == 0))
+                return (iRead==0) ? UNZ_EOF : iRead;
+
+            if (pfile_in_zip_read_info->stream.avail_out <
+                            pfile_in_zip_read_info->stream.avail_in)
+                uDoCopy = pfile_in_zip_read_info->stream.avail_out ;
+            else
+                uDoCopy = pfile_in_zip_read_info->stream.avail_in ;
+
+            for (i=0;i<uDoCopy;i++)
+                *(pfile_in_zip_read_info->stream.next_out+i) =
+                        *(pfile_in_zip_read_info->stream.next_in+i);
+
+            pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uDoCopy;
+
+            pfile_in_zip_read_info->crc32 = crc32(pfile_in_zip_read_info->crc32,
+                                pfile_in_zip_read_info->stream.next_out,
+                                uDoCopy);
+            pfile_in_zip_read_info->rest_read_uncompressed-=uDoCopy;
+            pfile_in_zip_read_info->stream.avail_in -= uDoCopy;
+            pfile_in_zip_read_info->stream.avail_out -= uDoCopy;
+            pfile_in_zip_read_info->stream.next_out += uDoCopy;
+            pfile_in_zip_read_info->stream.next_in += uDoCopy;
+            pfile_in_zip_read_info->stream.total_out += uDoCopy;
+            iRead += uDoCopy;
+        }
+        else if (pfile_in_zip_read_info->compression_method==Z_BZIP2ED)
+        {
+#ifdef HAVE_BZIP2
+            uLong uTotalOutBefore,uTotalOutAfter;
+            const Bytef *bufBefore;
+            uLong uOutThis;
+
+            pfile_in_zip_read_info->bstream.next_in        = (char*)pfile_in_zip_read_info->stream.next_in;
+            pfile_in_zip_read_info->bstream.avail_in       = pfile_in_zip_read_info->stream.avail_in;
+            pfile_in_zip_read_info->bstream.total_in_lo32  = pfile_in_zip_read_info->stream.total_in;
+            pfile_in_zip_read_info->bstream.total_in_hi32  = 0;
+            pfile_in_zip_read_info->bstream.next_out       = (char*)pfile_in_zip_read_info->stream.next_out;
+            pfile_in_zip_read_info->bstream.avail_out      = pfile_in_zip_read_info->stream.avail_out;
+            pfile_in_zip_read_info->bstream.total_out_lo32 = pfile_in_zip_read_info->stream.total_out;
+            pfile_in_zip_read_info->bstream.total_out_hi32 = 0;
+
+            uTotalOutBefore = pfile_in_zip_read_info->bstream.total_out_lo32;
+            bufBefore = (const Bytef *)pfile_in_zip_read_info->bstream.next_out;
+
+            err=BZ2_bzDecompress(&pfile_in_zip_read_info->bstream);
+
+            uTotalOutAfter = pfile_in_zip_read_info->bstream.total_out_lo32;
+            uOutThis = uTotalOutAfter-uTotalOutBefore;
+
+            pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uOutThis;
+
+            pfile_in_zip_read_info->crc32 = crc32(pfile_in_zip_read_info->crc32,bufBefore, (uInt)(uOutThis));
+            pfile_in_zip_read_info->rest_read_uncompressed -= uOutThis;
+            iRead += (uInt)(uTotalOutAfter - uTotalOutBefore);
+
+            pfile_in_zip_read_info->stream.next_in   = (Bytef*)pfile_in_zip_read_info->bstream.next_in;
+            pfile_in_zip_read_info->stream.avail_in  = pfile_in_zip_read_info->bstream.avail_in;
+            pfile_in_zip_read_info->stream.total_in  = pfile_in_zip_read_info->bstream.total_in_lo32;
+            pfile_in_zip_read_info->stream.next_out  = (Bytef*)pfile_in_zip_read_info->bstream.next_out;
+            pfile_in_zip_read_info->stream.avail_out = pfile_in_zip_read_info->bstream.avail_out;
+            pfile_in_zip_read_info->stream.total_out = pfile_in_zip_read_info->bstream.total_out_lo32;
+
+            if (err==BZ_STREAM_END)
+              return (iRead==0) ? UNZ_EOF : iRead;
+            if (err!=BZ_OK)
+              break;
+#endif
+        } // end Z_BZIP2ED
+        else
+        {
+            ZPOS64_T uTotalOutBefore,uTotalOutAfter;
+            const Bytef *bufBefore;
+            ZPOS64_T uOutThis;
+            int flush=Z_SYNC_FLUSH;
+
+            uTotalOutBefore = pfile_in_zip_read_info->stream.total_out;
+            bufBefore = pfile_in_zip_read_info->stream.next_out;
+
+            /*
+            if ((pfile_in_zip_read_info->rest_read_uncompressed ==
+                     pfile_in_zip_read_info->stream.avail_out) &&
+                (pfile_in_zip_read_info->rest_read_compressed == 0))
+                flush = Z_FINISH;
+            */
+            err=inflate(&pfile_in_zip_read_info->stream,flush);
+
+            if ((err>=0) && (pfile_in_zip_read_info->stream.msg!=NULL))
+              err = Z_DATA_ERROR;
+
+            uTotalOutAfter = pfile_in_zip_read_info->stream.total_out;
+            uOutThis = uTotalOutAfter-uTotalOutBefore;
+
+            pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uOutThis;
+
+            pfile_in_zip_read_info->crc32 =
+                crc32(pfile_in_zip_read_info->crc32,bufBefore,
+                        (uInt)(uOutThis));
+
+            pfile_in_zip_read_info->rest_read_uncompressed -=
+                uOutThis;
+
+            iRead += (uInt)(uTotalOutAfter - uTotalOutBefore);
+
+            if (err==Z_STREAM_END)
+                return (iRead==0) ? UNZ_EOF : iRead;
+            if (err!=Z_OK)
+                break;
+        }
+    }
+
+    if (err==Z_OK)
+        return iRead;
+    return err;
+}
+
+
+/*
+  Give the current position in uncompressed data
+*/
+extern z_off_t ZEXPORT unztell (unzFile file)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    return (z_off_t)pfile_in_zip_read_info->stream.total_out;
+}
+
+extern ZPOS64_T ZEXPORT unztell64 (unzFile file)
+{
+
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return (ZPOS64_T)-1;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return (ZPOS64_T)-1;
+
+    return pfile_in_zip_read_info->total_out_64;
+}
+
+
+/*
+  return 1 if the end of file was reached, 0 elsewhere
+*/
+extern int ZEXPORT unzeof (unzFile file)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    if (pfile_in_zip_read_info->rest_read_uncompressed == 0)
+        return 1;
+    else
+        return 0;
+}
+
+
+
+/*
+Read extra field from the current file (opened by unzOpenCurrentFile)
+This is the local-header version of the extra field (sometimes, there is
+more info in the local-header version than in the central-header)
+
+  if buf==NULL, it return the size of the local extra field that can be read
+
+  if buf!=NULL, len is the size of the buffer, the extra header is copied in
+    buf.
+  the return value is the number of bytes copied in buf, or (if <0)
+    the error code
+*/
+extern int ZEXPORT unzGetLocalExtrafield (unzFile file, voidp buf, unsigned len)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    uInt read_now;
+    ZPOS64_T size_to_read;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    size_to_read = (pfile_in_zip_read_info->size_local_extrafield -
+                pfile_in_zip_read_info->pos_local_extrafield);
+
+    if (buf==NULL)
+        return (int)size_to_read;
+
+    if (len>size_to_read)
+        read_now = (uInt)size_to_read;
+    else
+        read_now = (uInt)len ;
+
+    if (read_now==0)
+        return 0;
+
+    if (ZSEEK64(pfile_in_zip_read_info->z_filefunc,
+              pfile_in_zip_read_info->filestream,
+              pfile_in_zip_read_info->offset_local_extrafield +
+              pfile_in_zip_read_info->pos_local_extrafield,
+              ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return UNZ_ERRNO;
+
+    if (ZREAD64(pfile_in_zip_read_info->z_filefunc,
+              pfile_in_zip_read_info->filestream,
+              buf,read_now)!=read_now)
+        return UNZ_ERRNO;
+
+    return (int)read_now;
+}
+
+/*
+  Close the file in zip opened with unzOpenCurrentFile
+  Return UNZ_CRCERROR if all the file was read but the CRC is not good
+*/
+extern int ZEXPORT unzCloseCurrentFile (unzFile file)
+{
+    int err=UNZ_OK;
+
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+
+    if ((pfile_in_zip_read_info->rest_read_uncompressed == 0) &&
+        (!pfile_in_zip_read_info->raw))
+    {
+        if (pfile_in_zip_read_info->crc32 != pfile_in_zip_read_info->crc32_wait)
+            err=UNZ_CRCERROR;
+    }
+
+
+    TRYFREE(pfile_in_zip_read_info->read_buffer);
+    pfile_in_zip_read_info->read_buffer = NULL;
+    if (pfile_in_zip_read_info->stream_initialised == Z_DEFLATED)
+        inflateEnd(&pfile_in_zip_read_info->stream);
+#ifdef HAVE_BZIP2
+    else if (pfile_in_zip_read_info->stream_initialised == Z_BZIP2ED)
+        BZ2_bzDecompressEnd(&pfile_in_zip_read_info->bstream);
+#endif
+
+
+    pfile_in_zip_read_info->stream_initialised = 0;
+    TRYFREE(pfile_in_zip_read_info);
+
+    s->pfile_in_zip_read=NULL;
+
+    return err;
+}
+
+
+/*
+  Get the global comment string of the ZipFile, in the szComment buffer.
+  uSizeBuf is the size of the szComment buffer.
+  return the number of byte copied or an error code <0
+*/
+extern int ZEXPORT unzGetGlobalComment (unzFile file, char * szComment, uLong uSizeBuf)
+{
+    unz64_s* s;
+    uLong uReadThis ;
+    if (file==NULL)
+        return (int)UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    uReadThis = uSizeBuf;
+    if (uReadThis>s->gi.size_comment)
+        uReadThis = s->gi.size_comment;
+
+    if (ZSEEK64(s->z_filefunc,s->filestream,s->central_pos+22,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return UNZ_ERRNO;
+
+    if (uReadThis>0)
+    {
+      *szComment='\0';
+      if (ZREAD64(s->z_filefunc,s->filestream,szComment,uReadThis)!=uReadThis)
+        return UNZ_ERRNO;
+    }
+
+    if ((szComment != NULL) && (uSizeBuf > s->gi.size_comment))
+        *(szComment+s->gi.size_comment)='\0';
+    return (int)uReadThis;
+}
+
+/* Additions by RX '2004 */
+extern ZPOS64_T ZEXPORT unzGetOffset64(unzFile file)
+{
+    unz64_s* s;
+
+    if (file==NULL)
+          return 0; //UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+      return 0;
+    if (s->gi.number_entry != 0 && s->gi.number_entry != 0xffff)
+      if (s->num_file==s->gi.number_entry)
+         return 0;
+    return s->pos_in_central_dir;
+}
+
+extern uLong ZEXPORT unzGetOffset (unzFile file)
+{
+    ZPOS64_T offset64;
+
+    if (file==NULL)
+          return 0; //UNZ_PARAMERROR;
+    offset64 = unzGetOffset64(file);
+    return (uLong)offset64;
+}
+
+extern int ZEXPORT unzSetOffset64(unzFile file, ZPOS64_T pos)
+{
+    unz64_s* s;
+    int err;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    s->pos_in_central_dir = pos;
+    s->num_file = s->gi.number_entry;      /* hack */
+    err = unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                              &s->cur_file_info_internal,
+                                              NULL,0,NULL,0,NULL,0);
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+extern int ZEXPORT unzSetOffset (unzFile file, uLong pos)
+{
+    return unzSetOffset64(file,pos);
+}
diff --git a/xs/src/png/zlib/contrib/minizip/unzip.h b/xs/src/png/zlib/contrib/minizip/unzip.h
new file mode 100644
index 000000000..2104e3915
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/unzip.h
@@ -0,0 +1,437 @@
+/* unzip.h -- IO for uncompress .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         ---------------------------------------------------------------------------------
+
+        Condition of use and distribution are the same than zlib :
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  ---------------------------------------------------------------------------------
+
+        Changes
+
+        See header of unzip64.c
+
+*/
+
+#ifndef _unz64_H
+#define _unz64_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef _ZLIB_H
+#include "zlib.h"
+#endif
+
+#ifndef  _ZLIBIOAPI_H
+#include "ioapi.h"
+#endif
+
+#ifdef HAVE_BZIP2
+#include "bzlib.h"
+#endif
+
+#define Z_BZIP2ED 12
+
+#if defined(STRICTUNZIP) || defined(STRICTZIPUNZIP)
+/* like the STRICT of WIN32, we define a pointer that cannot be converted
+    from (void*) without cast */
+typedef struct TagunzFile__ { int unused; } unzFile__;
+typedef unzFile__ *unzFile;
+#else
+typedef voidp unzFile;
+#endif
+
+
+#define UNZ_OK                          (0)
+#define UNZ_END_OF_LIST_OF_FILE         (-100)
+#define UNZ_ERRNO                       (Z_ERRNO)
+#define UNZ_EOF                         (0)
+#define UNZ_PARAMERROR                  (-102)
+#define UNZ_BADZIPFILE                  (-103)
+#define UNZ_INTERNALERROR               (-104)
+#define UNZ_CRCERROR                    (-105)
+
+/* tm_unz contain date/time info */
+typedef struct tm_unz_s
+{
+    uInt tm_sec;            /* seconds after the minute - [0,59] */
+    uInt tm_min;            /* minutes after the hour - [0,59] */
+    uInt tm_hour;           /* hours since midnight - [0,23] */
+    uInt tm_mday;           /* day of the month - [1,31] */
+    uInt tm_mon;            /* months since January - [0,11] */
+    uInt tm_year;           /* years - [1980..2044] */
+} tm_unz;
+
+/* unz_global_info structure contain global data about the ZIPfile
+   These data comes from the end of central dir */
+typedef struct unz_global_info64_s
+{
+    ZPOS64_T number_entry;         /* total number of entries in
+                                     the central dir on this disk */
+    uLong size_comment;         /* size of the global comment of the zipfile */
+} unz_global_info64;
+
+typedef struct unz_global_info_s
+{
+    uLong number_entry;         /* total number of entries in
+                                     the central dir on this disk */
+    uLong size_comment;         /* size of the global comment of the zipfile */
+} unz_global_info;
+
+/* unz_file_info contain information about a file in the zipfile */
+typedef struct unz_file_info64_s
+{
+    uLong version;              /* version made by                 2 bytes */
+    uLong version_needed;       /* version needed to extract       2 bytes */
+    uLong flag;                 /* general purpose bit flag        2 bytes */
+    uLong compression_method;   /* compression method              2 bytes */
+    uLong dosDate;              /* last mod file date in Dos fmt   4 bytes */
+    uLong crc;                  /* crc-32                          4 bytes */
+    ZPOS64_T compressed_size;   /* compressed size                 8 bytes */
+    ZPOS64_T uncompressed_size; /* uncompressed size               8 bytes */
+    uLong size_filename;        /* filename length                 2 bytes */
+    uLong size_file_extra;      /* extra field length              2 bytes */
+    uLong size_file_comment;    /* file comment length             2 bytes */
+
+    uLong disk_num_start;       /* disk number start               2 bytes */
+    uLong internal_fa;          /* internal file attributes        2 bytes */
+    uLong external_fa;          /* external file attributes        4 bytes */
+
+    tm_unz tmu_date;
+} unz_file_info64;
+
+typedef struct unz_file_info_s
+{
+    uLong version;              /* version made by                 2 bytes */
+    uLong version_needed;       /* version needed to extract       2 bytes */
+    uLong flag;                 /* general purpose bit flag        2 bytes */
+    uLong compression_method;   /* compression method              2 bytes */
+    uLong dosDate;              /* last mod file date in Dos fmt   4 bytes */
+    uLong crc;                  /* crc-32                          4 bytes */
+    uLong compressed_size;      /* compressed size                 4 bytes */
+    uLong uncompressed_size;    /* uncompressed size               4 bytes */
+    uLong size_filename;        /* filename length                 2 bytes */
+    uLong size_file_extra;      /* extra field length              2 bytes */
+    uLong size_file_comment;    /* file comment length             2 bytes */
+
+    uLong disk_num_start;       /* disk number start               2 bytes */
+    uLong internal_fa;          /* internal file attributes        2 bytes */
+    uLong external_fa;          /* external file attributes        4 bytes */
+
+    tm_unz tmu_date;
+} unz_file_info;
+
+extern int ZEXPORT unzStringFileNameCompare OF ((const char* fileName1,
+                                                 const char* fileName2,
+                                                 int iCaseSensitivity));
+/*
+   Compare two filename (fileName1,fileName2).
+   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
+   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
+                                or strcasecmp)
+   If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
+    (like 1 on Unix, 2 on Windows)
+*/
+
+
+extern unzFile ZEXPORT unzOpen OF((const char *path));
+extern unzFile ZEXPORT unzOpen64 OF((const void *path));
+/*
+  Open a Zip file. path contain the full pathname (by example,
+     on a Windows XP computer "c:\\zlib\\zlib113.zip" or on an Unix computer
+     "zlib/zlib113.zip".
+     If the zipfile cannot be opened (file don't exist or in not valid), the
+       return value is NULL.
+     Else, the return value is a unzFile Handle, usable with other function
+       of this unzip package.
+     the "64" function take a const void* pointer, because the path is just the
+       value passed to the open64_file_func callback.
+     Under Windows, if UNICODE is defined, using fill_fopen64_filefunc, the path
+       is a pointer to a wide unicode string (LPCTSTR is LPCWSTR), so const char*
+       does not describe the reality
+*/
+
+
+extern unzFile ZEXPORT unzOpen2 OF((const char *path,
+                                    zlib_filefunc_def* pzlib_filefunc_def));
+/*
+   Open a Zip file, like unzOpen, but provide a set of file low level API
+      for read/write the zip file (see ioapi.h)
+*/
+
+extern unzFile ZEXPORT unzOpen2_64 OF((const void *path,
+                                    zlib_filefunc64_def* pzlib_filefunc_def));
+/*
+   Open a Zip file, like unz64Open, but provide a set of file low level API
+      for read/write the zip file (see ioapi.h)
+*/
+
+extern int ZEXPORT unzClose OF((unzFile file));
+/*
+  Close a ZipFile opened with unzOpen.
+  If there is files inside the .Zip opened with unzOpenCurrentFile (see later),
+    these files MUST be closed with unzCloseCurrentFile before call unzClose.
+  return UNZ_OK if there is no problem. */
+
+extern int ZEXPORT unzGetGlobalInfo OF((unzFile file,
+                                        unz_global_info *pglobal_info));
+
+extern int ZEXPORT unzGetGlobalInfo64 OF((unzFile file,
+                                        unz_global_info64 *pglobal_info));
+/*
+  Write info about the ZipFile in the *pglobal_info structure.
+  No preparation of the structure is needed
+  return UNZ_OK if there is no problem. */
+
+
+extern int ZEXPORT unzGetGlobalComment OF((unzFile file,
+                                           char *szComment,
+                                           uLong uSizeBuf));
+/*
+  Get the global comment string of the ZipFile, in the szComment buffer.
+  uSizeBuf is the size of the szComment buffer.
+  return the number of byte copied or an error code <0
+*/
+
+
+/***************************************************************************/
+/* Unzip package allow you browse the directory of the zipfile */
+
+extern int ZEXPORT unzGoToFirstFile OF((unzFile file));
+/*
+  Set the current file of the zipfile to the first file.
+  return UNZ_OK if there is no problem
+*/
+
+extern int ZEXPORT unzGoToNextFile OF((unzFile file));
+/*
+  Set the current file of the zipfile to the next file.
+  return UNZ_OK if there is no problem
+  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
+*/
+
+extern int ZEXPORT unzLocateFile OF((unzFile file,
+                     const char *szFileName,
+                     int iCaseSensitivity));
+/*
+  Try locate the file szFileName in the zipfile.
+  For the iCaseSensitivity signification, see unzStringFileNameCompare
+
+  return value :
+  UNZ_OK if the file is found. It becomes the current file.
+  UNZ_END_OF_LIST_OF_FILE if the file is not found
+*/
+
+
+/* ****************************************** */
+/* Ryan supplied functions */
+/* unz_file_info contain information about a file in the zipfile */
+typedef struct unz_file_pos_s
+{
+    uLong pos_in_zip_directory;   /* offset in zip file directory */
+    uLong num_of_file;            /* # of file */
+} unz_file_pos;
+
+extern int ZEXPORT unzGetFilePos(
+    unzFile file,
+    unz_file_pos* file_pos);
+
+extern int ZEXPORT unzGoToFilePos(
+    unzFile file,
+    unz_file_pos* file_pos);
+
+typedef struct unz64_file_pos_s
+{
+    ZPOS64_T pos_in_zip_directory;   /* offset in zip file directory */
+    ZPOS64_T num_of_file;            /* # of file */
+} unz64_file_pos;
+
+extern int ZEXPORT unzGetFilePos64(
+    unzFile file,
+    unz64_file_pos* file_pos);
+
+extern int ZEXPORT unzGoToFilePos64(
+    unzFile file,
+    const unz64_file_pos* file_pos);
+
+/* ****************************************** */
+
+extern int ZEXPORT unzGetCurrentFileInfo64 OF((unzFile file,
+                         unz_file_info64 *pfile_info,
+                         char *szFileName,
+                         uLong fileNameBufferSize,
+                         void *extraField,
+                         uLong extraFieldBufferSize,
+                         char *szComment,
+                         uLong commentBufferSize));
+
+extern int ZEXPORT unzGetCurrentFileInfo OF((unzFile file,
+                         unz_file_info *pfile_info,
+                         char *szFileName,
+                         uLong fileNameBufferSize,
+                         void *extraField,
+                         uLong extraFieldBufferSize,
+                         char *szComment,
+                         uLong commentBufferSize));
+/*
+  Get Info about the current file
+  if pfile_info!=NULL, the *pfile_info structure will contain somes info about
+        the current file
+  if szFileName!=NULL, the filemane string will be copied in szFileName
+            (fileNameBufferSize is the size of the buffer)
+  if extraField!=NULL, the extra field information will be copied in extraField
+            (extraFieldBufferSize is the size of the buffer).
+            This is the Central-header version of the extra field
+  if szComment!=NULL, the comment string of the file will be copied in szComment
+            (commentBufferSize is the size of the buffer)
+*/
+
+
+/** Addition for GDAL : START */
+
+extern ZPOS64_T ZEXPORT unzGetCurrentFileZStreamPos64 OF((unzFile file));
+
+/** Addition for GDAL : END */
+
+
+/***************************************************************************/
+/* for reading the content of the current zipfile, you can open it, read data
+   from it, and close it (you can close it before reading all the file)
+   */
+
+extern int ZEXPORT unzOpenCurrentFile OF((unzFile file));
+/*
+  Open for reading data the current file in the zipfile.
+  If there is no error, the return value is UNZ_OK.
+*/
+
+extern int ZEXPORT unzOpenCurrentFilePassword OF((unzFile file,
+                                                  const char* password));
+/*
+  Open for reading data the current file in the zipfile.
+  password is a crypting password
+  If there is no error, the return value is UNZ_OK.
+*/
+
+extern int ZEXPORT unzOpenCurrentFile2 OF((unzFile file,
+                                           int* method,
+                                           int* level,
+                                           int raw));
+/*
+  Same than unzOpenCurrentFile, but open for read raw the file (not uncompress)
+    if raw==1
+  *method will receive method of compression, *level will receive level of
+     compression
+  note : you can set level parameter as NULL (if you did not want known level,
+         but you CANNOT set method parameter as NULL
+*/
+
+extern int ZEXPORT unzOpenCurrentFile3 OF((unzFile file,
+                                           int* method,
+                                           int* level,
+                                           int raw,
+                                           const char* password));
+/*
+  Same than unzOpenCurrentFile, but open for read raw the file (not uncompress)
+    if raw==1
+  *method will receive method of compression, *level will receive level of
+     compression
+  note : you can set level parameter as NULL (if you did not want known level,
+         but you CANNOT set method parameter as NULL
+*/
+
+
+extern int ZEXPORT unzCloseCurrentFile OF((unzFile file));
+/*
+  Close the file in zip opened with unzOpenCurrentFile
+  Return UNZ_CRCERROR if all the file was read but the CRC is not good
+*/
+
+extern int ZEXPORT unzReadCurrentFile OF((unzFile file,
+                      voidp buf,
+                      unsigned len));
+/*
+  Read bytes from the current file (opened by unzOpenCurrentFile)
+  buf contain buffer where data must be copied
+  len the size of buf.
+
+  return the number of byte copied if somes bytes are copied
+  return 0 if the end of file was reached
+  return <0 with error code if there is an error
+    (UNZ_ERRNO for IO error, or zLib error for uncompress error)
+*/
+
+extern z_off_t ZEXPORT unztell OF((unzFile file));
+
+extern ZPOS64_T ZEXPORT unztell64 OF((unzFile file));
+/*
+  Give the current position in uncompressed data
+*/
+
+extern int ZEXPORT unzeof OF((unzFile file));
+/*
+  return 1 if the end of file was reached, 0 elsewhere
+*/
+
+extern int ZEXPORT unzGetLocalExtrafield OF((unzFile file,
+                                             voidp buf,
+                                             unsigned len));
+/*
+  Read extra field from the current file (opened by unzOpenCurrentFile)
+  This is the local-header version of the extra field (sometimes, there is
+    more info in the local-header version than in the central-header)
+
+  if buf==NULL, it return the size of the local extra field
+
+  if buf!=NULL, len is the size of the buffer, the extra header is copied in
+    buf.
+  the return value is the number of bytes copied in buf, or (if <0)
+    the error code
+*/
+
+/***************************************************************************/
+
+/* Get the current file offset */
+extern ZPOS64_T ZEXPORT unzGetOffset64 (unzFile file);
+extern uLong ZEXPORT unzGetOffset (unzFile file);
+
+/* Set the current file offset */
+extern int ZEXPORT unzSetOffset64 (unzFile file, ZPOS64_T pos);
+extern int ZEXPORT unzSetOffset (unzFile file, uLong pos);
+
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _unz64_H */
diff --git a/xs/src/png/zlib/contrib/minizip/zip.c b/xs/src/png/zlib/contrib/minizip/zip.c
new file mode 100644
index 000000000..44e88a9cb
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/zip.c
@@ -0,0 +1,2007 @@
+/* zip.c -- IO on .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         Changes
+   Oct-2009 - Mathias Svensson - Remove old C style function prototypes
+   Oct-2009 - Mathias Svensson - Added Zip64 Support when creating new file archives
+   Oct-2009 - Mathias Svensson - Did some code cleanup and refactoring to get better overview of some functions.
+   Oct-2009 - Mathias Svensson - Added zipRemoveExtraInfoBlock to strip extra field data from its ZIP64 data
+                                 It is used when recreting zip archive with RAW when deleting items from a zip.
+                                 ZIP64 data is automatically added to items that needs it, and existing ZIP64 data need to be removed.
+   Oct-2009 - Mathias Svensson - Added support for BZIP2 as compression mode (bzip2 lib is required)
+   Jan-2010 - back to unzip and minizip 1.0 name scheme, with compatibility layer
+
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "zlib.h"
+#include "zip.h"
+
+#ifdef STDC
+#  include <stddef.h>
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+#ifdef NO_ERRNO_H
+    extern int errno;
+#else
+#   include <errno.h>
+#endif
+
+
+#ifndef local
+#  define local static
+#endif
+/* compile with -Dlocal if your debugger can't find static symbols */
+
+#ifndef VERSIONMADEBY
+# define VERSIONMADEBY   (0x0) /* platform depedent */
+#endif
+
+#ifndef Z_BUFSIZE
+#define Z_BUFSIZE (64*1024) //(16384)
+#endif
+
+#ifndef Z_MAXFILENAMEINZIP
+#define Z_MAXFILENAMEINZIP (256)
+#endif
+
+#ifndef ALLOC
+# define ALLOC(size) (malloc(size))
+#endif
+#ifndef TRYFREE
+# define TRYFREE(p) {if (p) free(p);}
+#endif
+
+/*
+#define SIZECENTRALDIRITEM (0x2e)
+#define SIZEZIPLOCALHEADER (0x1e)
+*/
+
+/* I've found an old Unix (a SunOS 4.1.3_U1) without all SEEK_* defined.... */
+
+
+// NOT sure that this work on ALL platform
+#define MAKEULONG64(a, b) ((ZPOS64_T)(((unsigned long)(a)) | ((ZPOS64_T)((unsigned long)(b))) << 32))
+
+#ifndef SEEK_CUR
+#define SEEK_CUR    1
+#endif
+
+#ifndef SEEK_END
+#define SEEK_END    2
+#endif
+
+#ifndef SEEK_SET
+#define SEEK_SET    0
+#endif
+
+#ifndef DEF_MEM_LEVEL
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+#endif
+const char zip_copyright[] =" zip 1.01 Copyright 1998-2004 Gilles Vollant - http://www.winimage.com/zLibDll";
+
+
+#define SIZEDATA_INDATABLOCK (4096-(4*4))
+
+#define LOCALHEADERMAGIC    (0x04034b50)
+#define CENTRALHEADERMAGIC  (0x02014b50)
+#define ENDHEADERMAGIC      (0x06054b50)
+#define ZIP64ENDHEADERMAGIC      (0x6064b50)
+#define ZIP64ENDLOCHEADERMAGIC   (0x7064b50)
+
+#define FLAG_LOCALHEADER_OFFSET (0x06)
+#define CRC_LOCALHEADER_OFFSET  (0x0e)
+
+#define SIZECENTRALHEADER (0x2e) /* 46 */
+
+typedef struct linkedlist_datablock_internal_s
+{
+  struct linkedlist_datablock_internal_s* next_datablock;
+  uLong  avail_in_this_block;
+  uLong  filled_in_this_block;
+  uLong  unused; /* for future use and alignment */
+  unsigned char data[SIZEDATA_INDATABLOCK];
+} linkedlist_datablock_internal;
+
+typedef struct linkedlist_data_s
+{
+    linkedlist_datablock_internal* first_block;
+    linkedlist_datablock_internal* last_block;
+} linkedlist_data;
+
+
+typedef struct
+{
+    z_stream stream;            /* zLib stream structure for inflate */
+#ifdef HAVE_BZIP2
+    bz_stream bstream;          /* bzLib stream structure for bziped */
+#endif
+
+    int  stream_initialised;    /* 1 is stream is initialised */
+    uInt pos_in_buffered_data;  /* last written byte in buffered_data */
+
+    ZPOS64_T pos_local_header;     /* offset of the local header of the file
+                                     currenty writing */
+    char* central_header;       /* central header data for the current file */
+    uLong size_centralExtra;
+    uLong size_centralheader;   /* size of the central header for cur file */
+    uLong size_centralExtraFree; /* Extra bytes allocated to the centralheader but that are not used */
+    uLong flag;                 /* flag of the file currently writing */
+
+    int  method;                /* compression method of file currenty wr.*/
+    int  raw;                   /* 1 for directly writing raw data */
+    Byte buffered_data[Z_BUFSIZE];/* buffer contain compressed data to be writ*/
+    uLong dosDate;
+    uLong crc32;
+    int  encrypt;
+    int  zip64;               /* Add ZIP64 extened information in the extra field */
+    ZPOS64_T pos_zip64extrainfo;
+    ZPOS64_T totalCompressedData;
+    ZPOS64_T totalUncompressedData;
+#ifndef NOCRYPT
+    unsigned long keys[3];     /* keys defining the pseudo-random sequence */
+    const z_crc_t* pcrc_32_tab;
+    int crypt_header_size;
+#endif
+} curfile64_info;
+
+typedef struct
+{
+    zlib_filefunc64_32_def z_filefunc;
+    voidpf filestream;        /* io structore of the zipfile */
+    linkedlist_data central_dir;/* datablock with central dir in construction*/
+    int  in_opened_file_inzip;  /* 1 if a file in the zip is currently writ.*/
+    curfile64_info ci;            /* info on the file curretly writing */
+
+    ZPOS64_T begin_pos;            /* position of the beginning of the zipfile */
+    ZPOS64_T add_position_when_writing_offset;
+    ZPOS64_T number_entry;
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+    char *globalcomment;
+#endif
+
+} zip64_internal;
+
+
+#ifndef NOCRYPT
+#define INCLUDECRYPTINGCODE_IFCRYPTALLOWED
+#include "crypt.h"
+#endif
+
+local linkedlist_datablock_internal* allocate_new_datablock()
+{
+    linkedlist_datablock_internal* ldi;
+    ldi = (linkedlist_datablock_internal*)
+                 ALLOC(sizeof(linkedlist_datablock_internal));
+    if (ldi!=NULL)
+    {
+        ldi->next_datablock = NULL ;
+        ldi->filled_in_this_block = 0 ;
+        ldi->avail_in_this_block = SIZEDATA_INDATABLOCK ;
+    }
+    return ldi;
+}
+
+local void free_datablock(linkedlist_datablock_internal* ldi)
+{
+    while (ldi!=NULL)
+    {
+        linkedlist_datablock_internal* ldinext = ldi->next_datablock;
+        TRYFREE(ldi);
+        ldi = ldinext;
+    }
+}
+
+local void init_linkedlist(linkedlist_data* ll)
+{
+    ll->first_block = ll->last_block = NULL;
+}
+
+local void free_linkedlist(linkedlist_data* ll)
+{
+    free_datablock(ll->first_block);
+    ll->first_block = ll->last_block = NULL;
+}
+
+
+local int add_data_in_datablock(linkedlist_data* ll, const void* buf, uLong len)
+{
+    linkedlist_datablock_internal* ldi;
+    const unsigned char* from_copy;
+
+    if (ll==NULL)
+        return ZIP_INTERNALERROR;
+
+    if (ll->last_block == NULL)
+    {
+        ll->first_block = ll->last_block = allocate_new_datablock();
+        if (ll->first_block == NULL)
+            return ZIP_INTERNALERROR;
+    }
+
+    ldi = ll->last_block;
+    from_copy = (unsigned char*)buf;
+
+    while (len>0)
+    {
+        uInt copy_this;
+        uInt i;
+        unsigned char* to_copy;
+
+        if (ldi->avail_in_this_block==0)
+        {
+            ldi->next_datablock = allocate_new_datablock();
+            if (ldi->next_datablock == NULL)
+                return ZIP_INTERNALERROR;
+            ldi = ldi->next_datablock ;
+            ll->last_block = ldi;
+        }
+
+        if (ldi->avail_in_this_block < len)
+            copy_this = (uInt)ldi->avail_in_this_block;
+        else
+            copy_this = (uInt)len;
+
+        to_copy = &(ldi->data[ldi->filled_in_this_block]);
+
+        for (i=0;i<copy_this;i++)
+            *(to_copy+i)=*(from_copy+i);
+
+        ldi->filled_in_this_block += copy_this;
+        ldi->avail_in_this_block -= copy_this;
+        from_copy += copy_this ;
+        len -= copy_this;
+    }
+    return ZIP_OK;
+}
+
+
+
+/****************************************************************************/
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+/* ===========================================================================
+   Inputs a long in LSB order to the given file
+   nbByte == 1, 2 ,4 or 8 (byte, short or long, ZPOS64_T)
+*/
+
+local int zip64local_putValue OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T x, int nbByte));
+local int zip64local_putValue (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T x, int nbByte)
+{
+    unsigned char buf[8];
+    int n;
+    for (n = 0; n < nbByte; n++)
+    {
+        buf[n] = (unsigned char)(x & 0xff);
+        x >>= 8;
+    }
+    if (x != 0)
+      {     /* data overflow - hack for ZIP64 (X Roche) */
+      for (n = 0; n < nbByte; n++)
+        {
+          buf[n] = 0xff;
+        }
+      }
+
+    if (ZWRITE64(*pzlib_filefunc_def,filestream,buf,nbByte)!=(uLong)nbByte)
+        return ZIP_ERRNO;
+    else
+        return ZIP_OK;
+}
+
+local void zip64local_putValue_inmemory OF((void* dest, ZPOS64_T x, int nbByte));
+local void zip64local_putValue_inmemory (void* dest, ZPOS64_T x, int nbByte)
+{
+    unsigned char* buf=(unsigned char*)dest;
+    int n;
+    for (n = 0; n < nbByte; n++) {
+        buf[n] = (unsigned char)(x & 0xff);
+        x >>= 8;
+    }
+
+    if (x != 0)
+    {     /* data overflow - hack for ZIP64 */
+       for (n = 0; n < nbByte; n++)
+       {
+          buf[n] = 0xff;
+       }
+    }
+}
+
+/****************************************************************************/
+
+
+local uLong zip64local_TmzDateToDosDate(const tm_zip* ptm)
+{
+    uLong year = (uLong)ptm->tm_year;
+    if (year>=1980)
+        year-=1980;
+    else if (year>=80)
+        year-=80;
+    return
+      (uLong) (((ptm->tm_mday) + (32 * (ptm->tm_mon+1)) + (512 * year)) << 16) |
+        ((ptm->tm_sec/2) + (32* ptm->tm_min) + (2048 * (uLong)ptm->tm_hour));
+}
+
+
+/****************************************************************************/
+
+local int zip64local_getByte OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, int *pi));
+
+local int zip64local_getByte(const zlib_filefunc64_32_def* pzlib_filefunc_def,voidpf filestream,int* pi)
+{
+    unsigned char c;
+    int err = (int)ZREAD64(*pzlib_filefunc_def,filestream,&c,1);
+    if (err==1)
+    {
+        *pi = (int)c;
+        return ZIP_OK;
+    }
+    else
+    {
+        if (ZERROR64(*pzlib_filefunc_def,filestream))
+            return ZIP_ERRNO;
+        else
+            return ZIP_EOF;
+    }
+}
+
+
+/* ===========================================================================
+   Reads a long in LSB order from the given gz_stream. Sets
+*/
+local int zip64local_getShort OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong *pX));
+
+local int zip64local_getShort (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong* pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<8;
+
+    if (err==ZIP_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int zip64local_getLong OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong *pX));
+
+local int zip64local_getLong (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong* pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<8;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<16;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<24;
+
+    if (err==ZIP_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int zip64local_getLong64 OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T *pX));
+
+
+local int zip64local_getLong64 (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T *pX)
+{
+  ZPOS64_T x;
+  int i = 0;
+  int err;
+
+  err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x = (ZPOS64_T)i;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<8;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<16;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<24;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<32;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<40;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<48;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<56;
+
+  if (err==ZIP_OK)
+    *pX = x;
+  else
+    *pX = 0;
+
+  return err;
+}
+
+#ifndef BUFREADCOMMENT
+#define BUFREADCOMMENT (0x400)
+#endif
+/*
+  Locate the Central directory of a zipfile (at the end, just before
+    the global comment)
+*/
+local ZPOS64_T zip64local_SearchCentralDir OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream));
+
+local ZPOS64_T zip64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream)
+{
+  unsigned char* buf;
+  ZPOS64_T uSizeFile;
+  ZPOS64_T uBackRead;
+  ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+  ZPOS64_T uPosFound=0;
+
+  if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+    return 0;
+
+
+  uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+  if (uMaxBack>uSizeFile)
+    uMaxBack = uSizeFile;
+
+  buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+  if (buf==NULL)
+    return 0;
+
+  uBackRead = 4;
+  while (uBackRead<uMaxBack)
+  {
+    uLong uReadSize;
+    ZPOS64_T uReadPos ;
+    int i;
+    if (uBackRead+BUFREADCOMMENT>uMaxBack)
+      uBackRead = uMaxBack;
+    else
+      uBackRead+=BUFREADCOMMENT;
+    uReadPos = uSizeFile-uBackRead ;
+
+    uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+      (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+      break;
+
+    if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+      break;
+
+    for (i=(int)uReadSize-3; (i--)>0;)
+      if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) &&
+        ((*(buf+i+2))==0x05) && ((*(buf+i+3))==0x06))
+      {
+        uPosFound = uReadPos+i;
+        break;
+      }
+
+      if (uPosFound!=0)
+        break;
+  }
+  TRYFREE(buf);
+  return uPosFound;
+}
+
+/*
+Locate the End of Zip64 Central directory locator and from there find the CD of a zipfile (at the end, just before
+the global comment)
+*/
+local ZPOS64_T zip64local_SearchCentralDir64 OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream));
+
+local ZPOS64_T zip64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream)
+{
+  unsigned char* buf;
+  ZPOS64_T uSizeFile;
+  ZPOS64_T uBackRead;
+  ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+  ZPOS64_T uPosFound=0;
+  uLong uL;
+  ZPOS64_T relativeOffset;
+
+  if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+    return 0;
+
+  uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+  if (uMaxBack>uSizeFile)
+    uMaxBack = uSizeFile;
+
+  buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+  if (buf==NULL)
+    return 0;
+
+  uBackRead = 4;
+  while (uBackRead<uMaxBack)
+  {
+    uLong uReadSize;
+    ZPOS64_T uReadPos;
+    int i;
+    if (uBackRead+BUFREADCOMMENT>uMaxBack)
+      uBackRead = uMaxBack;
+    else
+      uBackRead+=BUFREADCOMMENT;
+    uReadPos = uSizeFile-uBackRead ;
+
+    uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+      (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+      break;
+
+    if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+      break;
+
+    for (i=(int)uReadSize-3; (i--)>0;)
+    {
+      // Signature "0x07064b50" Zip64 end of central directory locater
+      if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) && ((*(buf+i+2))==0x06) && ((*(buf+i+3))==0x07))
+      {
+        uPosFound = uReadPos+i;
+        break;
+      }
+    }
+
+      if (uPosFound!=0)
+        break;
+  }
+
+  TRYFREE(buf);
+  if (uPosFound == 0)
+    return 0;
+
+  /* Zip64 end of central directory locator */
+  if (ZSEEK64(*pzlib_filefunc_def,filestream, uPosFound,ZLIB_FILEFUNC_SEEK_SET)!=0)
+    return 0;
+
+  /* the signature, already checked */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+
+  /* number of the disk with the start of the zip64 end of  central directory */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+  if (uL != 0)
+    return 0;
+
+  /* relative offset of the zip64 end of central directory record */
+  if (zip64local_getLong64(pzlib_filefunc_def,filestream,&relativeOffset)!=ZIP_OK)
+    return 0;
+
+  /* total number of disks */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+  if (uL != 1)
+    return 0;
+
+  /* Goto Zip64 end of central directory record */
+  if (ZSEEK64(*pzlib_filefunc_def,filestream, relativeOffset,ZLIB_FILEFUNC_SEEK_SET)!=0)
+    return 0;
+
+  /* the signature */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+
+  if (uL != 0x06064b50) // signature of 'Zip64 end of central directory'
+    return 0;
+
+  return relativeOffset;
+}
+
+int LoadCentralDirectoryRecord(zip64_internal* pziinit)
+{
+  int err=ZIP_OK;
+  ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
+
+  ZPOS64_T size_central_dir;     /* size of the central directory  */
+  ZPOS64_T offset_central_dir;   /* offset of start of central directory */
+  ZPOS64_T central_pos;
+  uLong uL;
+
+  uLong number_disk;          /* number of the current dist, used for
+                              spaning ZIP, unsupported, always 0*/
+  uLong number_disk_with_CD;  /* number the the disk with central dir, used
+                              for spaning ZIP, unsupported, always 0*/
+  ZPOS64_T number_entry;
+  ZPOS64_T number_entry_CD;      /* total number of entries in
+                                the central dir
+                                (same than number_entry on nospan) */
+  uLong VersionMadeBy;
+  uLong VersionNeeded;
+  uLong size_comment;
+
+  int hasZIP64Record = 0;
+
+  // check first if we find a ZIP64 record
+  central_pos = zip64local_SearchCentralDir64(&pziinit->z_filefunc,pziinit->filestream);
+  if(central_pos > 0)
+  {
+    hasZIP64Record = 1;
+  }
+  else if(central_pos == 0)
+  {
+    central_pos = zip64local_SearchCentralDir(&pziinit->z_filefunc,pziinit->filestream);
+  }
+
+/* disable to allow appending to empty ZIP archive
+        if (central_pos==0)
+            err=ZIP_ERRNO;
+*/
+
+  if(hasZIP64Record)
+  {
+    ZPOS64_T sizeEndOfCentralDirectory;
+    if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, central_pos, ZLIB_FILEFUNC_SEEK_SET) != 0)
+      err=ZIP_ERRNO;
+
+    /* the signature, already checked */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* size of zip64 end of central directory record */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream, &sizeEndOfCentralDirectory)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* version made by */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &VersionMadeBy)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* version needed to extract */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &VersionNeeded)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of this disk */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&number_disk)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of the disk with the start of the central directory */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&number_disk_with_CD)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* total number of entries in the central directory on this disk */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream, &number_entry)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* total number of entries in the central directory */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream,&number_entry_CD)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    if ((number_entry_CD!=number_entry) || (number_disk_with_CD!=0) || (number_disk!=0))
+      err=ZIP_BADZIPFILE;
+
+    /* size of the central directory */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream,&size_central_dir)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* offset of start of central directory with respect to the
+    starting disk number */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream,&offset_central_dir)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    // TODO..
+    // read the comment from the standard central header.
+    size_comment = 0;
+  }
+  else
+  {
+    // Read End of central Directory info
+    if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, central_pos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+      err=ZIP_ERRNO;
+
+    /* the signature, already checked */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of this disk */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream,&number_disk)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of the disk with the start of the central directory */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream,&number_disk_with_CD)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* total number of entries in the central dir on this disk */
+    number_entry = 0;
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      number_entry = uL;
+
+    /* total number of entries in the central dir */
+    number_entry_CD = 0;
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      number_entry_CD = uL;
+
+    if ((number_entry_CD!=number_entry) || (number_disk_with_CD!=0) || (number_disk!=0))
+      err=ZIP_BADZIPFILE;
+
+    /* size of the central directory */
+    size_central_dir = 0;
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      size_central_dir = uL;
+
+    /* offset of start of central directory with respect to the starting disk number */
+    offset_central_dir = 0;
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      offset_central_dir = uL;
+
+
+    /* zipfile global comment length */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &size_comment)!=ZIP_OK)
+      err=ZIP_ERRNO;
+  }
+
+  if ((central_pos<offset_central_dir+size_central_dir) &&
+    (err==ZIP_OK))
+    err=ZIP_BADZIPFILE;
+
+  if (err!=ZIP_OK)
+  {
+    ZCLOSE64(pziinit->z_filefunc, pziinit->filestream);
+    return ZIP_ERRNO;
+  }
+
+  if (size_comment>0)
+  {
+    pziinit->globalcomment = (char*)ALLOC(size_comment+1);
+    if (pziinit->globalcomment)
+    {
+      size_comment = ZREAD64(pziinit->z_filefunc, pziinit->filestream, pziinit->globalcomment,size_comment);
+      pziinit->globalcomment[size_comment]=0;
+    }
+  }
+
+  byte_before_the_zipfile = central_pos - (offset_central_dir+size_central_dir);
+  pziinit->add_position_when_writing_offset = byte_before_the_zipfile;
+
+  {
+    ZPOS64_T size_central_dir_to_read = size_central_dir;
+    size_t buf_size = SIZEDATA_INDATABLOCK;
+    void* buf_read = (void*)ALLOC(buf_size);
+    if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, offset_central_dir + byte_before_the_zipfile, ZLIB_FILEFUNC_SEEK_SET) != 0)
+      err=ZIP_ERRNO;
+
+    while ((size_central_dir_to_read>0) && (err==ZIP_OK))
+    {
+      ZPOS64_T read_this = SIZEDATA_INDATABLOCK;
+      if (read_this > size_central_dir_to_read)
+        read_this = size_central_dir_to_read;
+
+      if (ZREAD64(pziinit->z_filefunc, pziinit->filestream,buf_read,(uLong)read_this) != read_this)
+        err=ZIP_ERRNO;
+
+      if (err==ZIP_OK)
+        err = add_data_in_datablock(&pziinit->central_dir,buf_read, (uLong)read_this);
+
+      size_central_dir_to_read-=read_this;
+    }
+    TRYFREE(buf_read);
+  }
+  pziinit->begin_pos = byte_before_the_zipfile;
+  pziinit->number_entry = number_entry_CD;
+
+  if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, offset_central_dir+byte_before_the_zipfile,ZLIB_FILEFUNC_SEEK_SET) != 0)
+    err=ZIP_ERRNO;
+
+  return err;
+}
+
+
+#endif /* !NO_ADDFILEINEXISTINGZIP*/
+
+
+/************************************************************/
+extern zipFile ZEXPORT zipOpen3 (const void *pathname, int append, zipcharpc* globalcomment, zlib_filefunc64_32_def* pzlib_filefunc64_32_def)
+{
+    zip64_internal ziinit;
+    zip64_internal* zi;
+    int err=ZIP_OK;
+
+    ziinit.z_filefunc.zseek32_file = NULL;
+    ziinit.z_filefunc.ztell32_file = NULL;
+    if (pzlib_filefunc64_32_def==NULL)
+        fill_fopen64_filefunc(&ziinit.z_filefunc.zfile_func64);
+    else
+        ziinit.z_filefunc = *pzlib_filefunc64_32_def;
+
+    ziinit.filestream = ZOPEN64(ziinit.z_filefunc,
+                  pathname,
+                  (append == APPEND_STATUS_CREATE) ?
+                  (ZLIB_FILEFUNC_MODE_READ | ZLIB_FILEFUNC_MODE_WRITE | ZLIB_FILEFUNC_MODE_CREATE) :
+                    (ZLIB_FILEFUNC_MODE_READ | ZLIB_FILEFUNC_MODE_WRITE | ZLIB_FILEFUNC_MODE_EXISTING));
+
+    if (ziinit.filestream == NULL)
+        return NULL;
+
+    if (append == APPEND_STATUS_CREATEAFTER)
+        ZSEEK64(ziinit.z_filefunc,ziinit.filestream,0,SEEK_END);
+
+    ziinit.begin_pos = ZTELL64(ziinit.z_filefunc,ziinit.filestream);
+    ziinit.in_opened_file_inzip = 0;
+    ziinit.ci.stream_initialised = 0;
+    ziinit.number_entry = 0;
+    ziinit.add_position_when_writing_offset = 0;
+    init_linkedlist(&(ziinit.central_dir));
+
+
+
+    zi = (zip64_internal*)ALLOC(sizeof(zip64_internal));
+    if (zi==NULL)
+    {
+        ZCLOSE64(ziinit.z_filefunc,ziinit.filestream);
+        return NULL;
+    }
+
+    /* now we add file in a zipfile */
+#    ifndef NO_ADDFILEINEXISTINGZIP
+    ziinit.globalcomment = NULL;
+    if (append == APPEND_STATUS_ADDINZIP)
+    {
+      // Read and Cache Central Directory Records
+      err = LoadCentralDirectoryRecord(&ziinit);
+    }
+
+    if (globalcomment)
+    {
+      *globalcomment = ziinit.globalcomment;
+    }
+#    endif /* !NO_ADDFILEINEXISTINGZIP*/
+
+    if (err != ZIP_OK)
+    {
+#    ifndef NO_ADDFILEINEXISTINGZIP
+        TRYFREE(ziinit.globalcomment);
+#    endif /* !NO_ADDFILEINEXISTINGZIP*/
+        TRYFREE(zi);
+        return NULL;
+    }
+    else
+    {
+        *zi = ziinit;
+        return (zipFile)zi;
+    }
+}
+
+extern zipFile ZEXPORT zipOpen2 (const char *pathname, int append, zipcharpc* globalcomment, zlib_filefunc_def* pzlib_filefunc32_def)
+{
+    if (pzlib_filefunc32_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        fill_zlib_filefunc64_32_def_from_filefunc32(&zlib_filefunc64_32_def_fill,pzlib_filefunc32_def);
+        return zipOpen3(pathname, append, globalcomment, &zlib_filefunc64_32_def_fill);
+    }
+    else
+        return zipOpen3(pathname, append, globalcomment, NULL);
+}
+
+extern zipFile ZEXPORT zipOpen2_64 (const void *pathname, int append, zipcharpc* globalcomment, zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    if (pzlib_filefunc_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        zlib_filefunc64_32_def_fill.zfile_func64 = *pzlib_filefunc_def;
+        zlib_filefunc64_32_def_fill.ztell32_file = NULL;
+        zlib_filefunc64_32_def_fill.zseek32_file = NULL;
+        return zipOpen3(pathname, append, globalcomment, &zlib_filefunc64_32_def_fill);
+    }
+    else
+        return zipOpen3(pathname, append, globalcomment, NULL);
+}
+
+
+
+extern zipFile ZEXPORT zipOpen (const char* pathname, int append)
+{
+    return zipOpen3((const void*)pathname,append,NULL,NULL);
+}
+
+extern zipFile ZEXPORT zipOpen64 (const void* pathname, int append)
+{
+    return zipOpen3(pathname,append,NULL,NULL);
+}
+
+int Write_LocalFileHeader(zip64_internal* zi, const char* filename, uInt size_extrafield_local, const void* extrafield_local)
+{
+  /* write the local header */
+  int err;
+  uInt size_filename = (uInt)strlen(filename);
+  uInt size_extrafield = size_extrafield_local;
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)LOCALHEADERMAGIC, 4);
+
+  if (err==ZIP_OK)
+  {
+    if(zi->ci.zip64)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)45,2);/* version needed to extract */
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)20,2);/* version needed to extract */
+  }
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->ci.flag,2);
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->ci.method,2);
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->ci.dosDate,4);
+
+  // CRC / Compressed size / Uncompressed size will be filled in later and rewritten later
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4); /* crc 32, unknown */
+  if (err==ZIP_OK)
+  {
+    if(zi->ci.zip64)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xFFFFFFFF,4); /* compressed size, unknown */
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4); /* compressed size, unknown */
+  }
+  if (err==ZIP_OK)
+  {
+    if(zi->ci.zip64)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xFFFFFFFF,4); /* uncompressed size, unknown */
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4); /* uncompressed size, unknown */
+  }
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_filename,2);
+
+  if(zi->ci.zip64)
+  {
+    size_extrafield += 20;
+  }
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_extrafield,2);
+
+  if ((err==ZIP_OK) && (size_filename > 0))
+  {
+    if (ZWRITE64(zi->z_filefunc,zi->filestream,filename,size_filename)!=size_filename)
+      err = ZIP_ERRNO;
+  }
+
+  if ((err==ZIP_OK) && (size_extrafield_local > 0))
+  {
+    if (ZWRITE64(zi->z_filefunc, zi->filestream, extrafield_local, size_extrafield_local) != size_extrafield_local)
+      err = ZIP_ERRNO;
+  }
+
+
+  if ((err==ZIP_OK) && (zi->ci.zip64))
+  {
+      // write the Zip64 extended info
+      short HeaderID = 1;
+      short DataSize = 16;
+      ZPOS64_T CompressedSize = 0;
+      ZPOS64_T UncompressedSize = 0;
+
+      // Remember position of Zip64 extended info for the local file header. (needed when we update size after done with file)
+      zi->ci.pos_zip64extrainfo = ZTELL64(zi->z_filefunc,zi->filestream);
+
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (short)HeaderID,2);
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (short)DataSize,2);
+
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (ZPOS64_T)UncompressedSize,8);
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (ZPOS64_T)CompressedSize,8);
+  }
+
+  return err;
+}
+
+/*
+ NOTE.
+ When writing RAW the ZIP64 extended information in extrafield_local and extrafield_global needs to be stripped
+ before calling this function it can be done with zipRemoveExtraInfoBlock
+
+ It is not done here because then we need to realloc a new buffer since parameters are 'const' and I want to minimize
+ unnecessary allocations.
+ */
+extern int ZEXPORT zipOpenNewFileInZip4_64 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting,
+                                         uLong versionMadeBy, uLong flagBase, int zip64)
+{
+    zip64_internal* zi;
+    uInt size_filename;
+    uInt size_comment;
+    uInt i;
+    int err = ZIP_OK;
+
+#    ifdef NOCRYPT
+    (crcForCrypting);
+    if (password != NULL)
+        return ZIP_PARAMERROR;
+#    endif
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+
+#ifdef HAVE_BZIP2
+    if ((method!=0) && (method!=Z_DEFLATED) && (method!=Z_BZIP2ED))
+      return ZIP_PARAMERROR;
+#else
+    if ((method!=0) && (method!=Z_DEFLATED))
+      return ZIP_PARAMERROR;
+#endif
+
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 1)
+    {
+        err = zipCloseFileInZip (file);
+        if (err != ZIP_OK)
+            return err;
+    }
+
+    if (filename==NULL)
+        filename="-";
+
+    if (comment==NULL)
+        size_comment = 0;
+    else
+        size_comment = (uInt)strlen(comment);
+
+    size_filename = (uInt)strlen(filename);
+
+    if (zipfi == NULL)
+        zi->ci.dosDate = 0;
+    else
+    {
+        if (zipfi->dosDate != 0)
+            zi->ci.dosDate = zipfi->dosDate;
+        else
+          zi->ci.dosDate = zip64local_TmzDateToDosDate(&zipfi->tmz_date);
+    }
+
+    zi->ci.flag = flagBase;
+    if ((level==8) || (level==9))
+      zi->ci.flag |= 2;
+    if (level==2)
+      zi->ci.flag |= 4;
+    if (level==1)
+      zi->ci.flag |= 6;
+    if (password != NULL)
+      zi->ci.flag |= 1;
+
+    zi->ci.crc32 = 0;
+    zi->ci.method = method;
+    zi->ci.encrypt = 0;
+    zi->ci.stream_initialised = 0;
+    zi->ci.pos_in_buffered_data = 0;
+    zi->ci.raw = raw;
+    zi->ci.pos_local_header = ZTELL64(zi->z_filefunc,zi->filestream);
+
+    zi->ci.size_centralheader = SIZECENTRALHEADER + size_filename + size_extrafield_global + size_comment;
+    zi->ci.size_centralExtraFree = 32; // Extra space we have reserved in case we need to add ZIP64 extra info data
+
+    zi->ci.central_header = (char*)ALLOC((uInt)zi->ci.size_centralheader + zi->ci.size_centralExtraFree);
+
+    zi->ci.size_centralExtra = size_extrafield_global;
+    zip64local_putValue_inmemory(zi->ci.central_header,(uLong)CENTRALHEADERMAGIC,4);
+    /* version info */
+    zip64local_putValue_inmemory(zi->ci.central_header+4,(uLong)versionMadeBy,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+6,(uLong)20,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+8,(uLong)zi->ci.flag,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+10,(uLong)zi->ci.method,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+12,(uLong)zi->ci.dosDate,4);
+    zip64local_putValue_inmemory(zi->ci.central_header+16,(uLong)0,4); /*crc*/
+    zip64local_putValue_inmemory(zi->ci.central_header+20,(uLong)0,4); /*compr size*/
+    zip64local_putValue_inmemory(zi->ci.central_header+24,(uLong)0,4); /*uncompr size*/
+    zip64local_putValue_inmemory(zi->ci.central_header+28,(uLong)size_filename,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+30,(uLong)size_extrafield_global,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+32,(uLong)size_comment,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+34,(uLong)0,2); /*disk nm start*/
+
+    if (zipfi==NULL)
+        zip64local_putValue_inmemory(zi->ci.central_header+36,(uLong)0,2);
+    else
+        zip64local_putValue_inmemory(zi->ci.central_header+36,(uLong)zipfi->internal_fa,2);
+
+    if (zipfi==NULL)
+        zip64local_putValue_inmemory(zi->ci.central_header+38,(uLong)0,4);
+    else
+        zip64local_putValue_inmemory(zi->ci.central_header+38,(uLong)zipfi->external_fa,4);
+
+    if(zi->ci.pos_local_header >= 0xffffffff)
+      zip64local_putValue_inmemory(zi->ci.central_header+42,(uLong)0xffffffff,4);
+    else
+      zip64local_putValue_inmemory(zi->ci.central_header+42,(uLong)zi->ci.pos_local_header - zi->add_position_when_writing_offset,4);
+
+    for (i=0;i<size_filename;i++)
+        *(zi->ci.central_header+SIZECENTRALHEADER+i) = *(filename+i);
+
+    for (i=0;i<size_extrafield_global;i++)
+        *(zi->ci.central_header+SIZECENTRALHEADER+size_filename+i) =
+              *(((const char*)extrafield_global)+i);
+
+    for (i=0;i<size_comment;i++)
+        *(zi->ci.central_header+SIZECENTRALHEADER+size_filename+
+              size_extrafield_global+i) = *(comment+i);
+    if (zi->ci.central_header == NULL)
+        return ZIP_INTERNALERROR;
+
+    zi->ci.zip64 = zip64;
+    zi->ci.totalCompressedData = 0;
+    zi->ci.totalUncompressedData = 0;
+    zi->ci.pos_zip64extrainfo = 0;
+
+    err = Write_LocalFileHeader(zi, filename, size_extrafield_local, extrafield_local);
+
+#ifdef HAVE_BZIP2
+    zi->ci.bstream.avail_in = (uInt)0;
+    zi->ci.bstream.avail_out = (uInt)Z_BUFSIZE;
+    zi->ci.bstream.next_out = (char*)zi->ci.buffered_data;
+    zi->ci.bstream.total_in_hi32 = 0;
+    zi->ci.bstream.total_in_lo32 = 0;
+    zi->ci.bstream.total_out_hi32 = 0;
+    zi->ci.bstream.total_out_lo32 = 0;
+#endif
+
+    zi->ci.stream.avail_in = (uInt)0;
+    zi->ci.stream.avail_out = (uInt)Z_BUFSIZE;
+    zi->ci.stream.next_out = zi->ci.buffered_data;
+    zi->ci.stream.total_in = 0;
+    zi->ci.stream.total_out = 0;
+    zi->ci.stream.data_type = Z_BINARY;
+
+#ifdef HAVE_BZIP2
+    if ((err==ZIP_OK) && (zi->ci.method == Z_DEFLATED || zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+#else
+    if ((err==ZIP_OK) && (zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+#endif
+    {
+        if(zi->ci.method == Z_DEFLATED)
+        {
+          zi->ci.stream.zalloc = (alloc_func)0;
+          zi->ci.stream.zfree = (free_func)0;
+          zi->ci.stream.opaque = (voidpf)0;
+
+          if (windowBits>0)
+              windowBits = -windowBits;
+
+          err = deflateInit2(&zi->ci.stream, level, Z_DEFLATED, windowBits, memLevel, strategy);
+
+          if (err==Z_OK)
+              zi->ci.stream_initialised = Z_DEFLATED;
+        }
+        else if(zi->ci.method == Z_BZIP2ED)
+        {
+#ifdef HAVE_BZIP2
+            // Init BZip stuff here
+          zi->ci.bstream.bzalloc = 0;
+          zi->ci.bstream.bzfree = 0;
+          zi->ci.bstream.opaque = (voidpf)0;
+
+          err = BZ2_bzCompressInit(&zi->ci.bstream, level, 0,35);
+          if(err == BZ_OK)
+            zi->ci.stream_initialised = Z_BZIP2ED;
+#endif
+        }
+
+    }
+
+#    ifndef NOCRYPT
+    zi->ci.crypt_header_size = 0;
+    if ((err==Z_OK) && (password != NULL))
+    {
+        unsigned char bufHead[RAND_HEAD_LEN];
+        unsigned int sizeHead;
+        zi->ci.encrypt = 1;
+        zi->ci.pcrc_32_tab = get_crc_table();
+        /*init_keys(password,zi->ci.keys,zi->ci.pcrc_32_tab);*/
+
+        sizeHead=crypthead(password,bufHead,RAND_HEAD_LEN,zi->ci.keys,zi->ci.pcrc_32_tab,crcForCrypting);
+        zi->ci.crypt_header_size = sizeHead;
+
+        if (ZWRITE64(zi->z_filefunc,zi->filestream,bufHead,sizeHead) != sizeHead)
+                err = ZIP_ERRNO;
+    }
+#    endif
+
+    if (err==Z_OK)
+        zi->in_opened_file_inzip = 1;
+    return err;
+}
+
+extern int ZEXPORT zipOpenNewFileInZip4 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting,
+                                         uLong versionMadeBy, uLong flagBase)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 windowBits, memLevel, strategy,
+                                 password, crcForCrypting, versionMadeBy, flagBase, 0);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip3 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 windowBits, memLevel, strategy,
+                                 password, crcForCrypting, VERSIONMADEBY, 0, 0);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip3_64(zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting, int zip64)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 windowBits, memLevel, strategy,
+                                 password, crcForCrypting, VERSIONMADEBY, 0, zip64);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip2(zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void* extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level, int raw)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, 0);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip2_64(zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void* extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level, int raw, int zip64)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, zip64);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip64 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void*extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level, int zip64)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, 0,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, zip64);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void*extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, 0,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, 0);
+}
+
+local int zip64FlushWriteBuffer(zip64_internal* zi)
+{
+    int err=ZIP_OK;
+
+    if (zi->ci.encrypt != 0)
+    {
+#ifndef NOCRYPT
+        uInt i;
+        int t;
+        for (i=0;i<zi->ci.pos_in_buffered_data;i++)
+            zi->ci.buffered_data[i] = zencode(zi->ci.keys, zi->ci.pcrc_32_tab, zi->ci.buffered_data[i],t);
+#endif
+    }
+
+    if (ZWRITE64(zi->z_filefunc,zi->filestream,zi->ci.buffered_data,zi->ci.pos_in_buffered_data) != zi->ci.pos_in_buffered_data)
+      err = ZIP_ERRNO;
+
+    zi->ci.totalCompressedData += zi->ci.pos_in_buffered_data;
+
+#ifdef HAVE_BZIP2
+    if(zi->ci.method == Z_BZIP2ED)
+    {
+      zi->ci.totalUncompressedData += zi->ci.bstream.total_in_lo32;
+      zi->ci.bstream.total_in_lo32 = 0;
+      zi->ci.bstream.total_in_hi32 = 0;
+    }
+    else
+#endif
+    {
+      zi->ci.totalUncompressedData += zi->ci.stream.total_in;
+      zi->ci.stream.total_in = 0;
+    }
+
+
+    zi->ci.pos_in_buffered_data = 0;
+
+    return err;
+}
+
+extern int ZEXPORT zipWriteInFileInZip (zipFile file,const void* buf,unsigned int len)
+{
+    zip64_internal* zi;
+    int err=ZIP_OK;
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 0)
+        return ZIP_PARAMERROR;
+
+    zi->ci.crc32 = crc32(zi->ci.crc32,buf,(uInt)len);
+
+#ifdef HAVE_BZIP2
+    if(zi->ci.method == Z_BZIP2ED && (!zi->ci.raw))
+    {
+      zi->ci.bstream.next_in = (void*)buf;
+      zi->ci.bstream.avail_in = len;
+      err = BZ_RUN_OK;
+
+      while ((err==BZ_RUN_OK) && (zi->ci.bstream.avail_in>0))
+      {
+        if (zi->ci.bstream.avail_out == 0)
+        {
+          if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+            err = ZIP_ERRNO;
+          zi->ci.bstream.avail_out = (uInt)Z_BUFSIZE;
+          zi->ci.bstream.next_out = (char*)zi->ci.buffered_data;
+        }
+
+
+        if(err != BZ_RUN_OK)
+          break;
+
+        if ((zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+        {
+          uLong uTotalOutBefore_lo = zi->ci.bstream.total_out_lo32;
+//          uLong uTotalOutBefore_hi = zi->ci.bstream.total_out_hi32;
+          err=BZ2_bzCompress(&zi->ci.bstream,  BZ_RUN);
+
+          zi->ci.pos_in_buffered_data += (uInt)(zi->ci.bstream.total_out_lo32 - uTotalOutBefore_lo) ;
+        }
+      }
+
+      if(err == BZ_RUN_OK)
+        err = ZIP_OK;
+    }
+    else
+#endif
+    {
+      zi->ci.stream.next_in = (Bytef*)buf;
+      zi->ci.stream.avail_in = len;
+
+      while ((err==ZIP_OK) && (zi->ci.stream.avail_in>0))
+      {
+          if (zi->ci.stream.avail_out == 0)
+          {
+              if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+                  err = ZIP_ERRNO;
+              zi->ci.stream.avail_out = (uInt)Z_BUFSIZE;
+              zi->ci.stream.next_out = zi->ci.buffered_data;
+          }
+
+
+          if(err != ZIP_OK)
+              break;
+
+          if ((zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+          {
+              uLong uTotalOutBefore = zi->ci.stream.total_out;
+              err=deflate(&zi->ci.stream,  Z_NO_FLUSH);
+              if(uTotalOutBefore > zi->ci.stream.total_out)
+              {
+                int bBreak = 0;
+                bBreak++;
+              }
+
+              zi->ci.pos_in_buffered_data += (uInt)(zi->ci.stream.total_out - uTotalOutBefore) ;
+          }
+          else
+          {
+              uInt copy_this,i;
+              if (zi->ci.stream.avail_in < zi->ci.stream.avail_out)
+                  copy_this = zi->ci.stream.avail_in;
+              else
+                  copy_this = zi->ci.stream.avail_out;
+
+              for (i = 0; i < copy_this; i++)
+                  *(((char*)zi->ci.stream.next_out)+i) =
+                      *(((const char*)zi->ci.stream.next_in)+i);
+              {
+                  zi->ci.stream.avail_in -= copy_this;
+                  zi->ci.stream.avail_out-= copy_this;
+                  zi->ci.stream.next_in+= copy_this;
+                  zi->ci.stream.next_out+= copy_this;
+                  zi->ci.stream.total_in+= copy_this;
+                  zi->ci.stream.total_out+= copy_this;
+                  zi->ci.pos_in_buffered_data += copy_this;
+              }
+          }
+      }// while(...)
+    }
+
+    return err;
+}
+
+extern int ZEXPORT zipCloseFileInZipRaw (zipFile file, uLong uncompressed_size, uLong crc32)
+{
+    return zipCloseFileInZipRaw64 (file, uncompressed_size, crc32);
+}
+
+extern int ZEXPORT zipCloseFileInZipRaw64 (zipFile file, ZPOS64_T uncompressed_size, uLong crc32)
+{
+    zip64_internal* zi;
+    ZPOS64_T compressed_size;
+    uLong invalidValue = 0xffffffff;
+    short datasize = 0;
+    int err=ZIP_OK;
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 0)
+        return ZIP_PARAMERROR;
+    zi->ci.stream.avail_in = 0;
+
+    if ((zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+                {
+                        while (err==ZIP_OK)
+                        {
+                                uLong uTotalOutBefore;
+                                if (zi->ci.stream.avail_out == 0)
+                                {
+                                        if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+                                                err = ZIP_ERRNO;
+                                        zi->ci.stream.avail_out = (uInt)Z_BUFSIZE;
+                                        zi->ci.stream.next_out = zi->ci.buffered_data;
+                                }
+                                uTotalOutBefore = zi->ci.stream.total_out;
+                                err=deflate(&zi->ci.stream,  Z_FINISH);
+                                zi->ci.pos_in_buffered_data += (uInt)(zi->ci.stream.total_out - uTotalOutBefore) ;
+                        }
+                }
+    else if ((zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+    {
+#ifdef HAVE_BZIP2
+      err = BZ_FINISH_OK;
+      while (err==BZ_FINISH_OK)
+      {
+        uLong uTotalOutBefore;
+        if (zi->ci.bstream.avail_out == 0)
+        {
+          if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+            err = ZIP_ERRNO;
+          zi->ci.bstream.avail_out = (uInt)Z_BUFSIZE;
+          zi->ci.bstream.next_out = (char*)zi->ci.buffered_data;
+        }
+        uTotalOutBefore = zi->ci.bstream.total_out_lo32;
+        err=BZ2_bzCompress(&zi->ci.bstream,  BZ_FINISH);
+        if(err == BZ_STREAM_END)
+          err = Z_STREAM_END;
+
+        zi->ci.pos_in_buffered_data += (uInt)(zi->ci.bstream.total_out_lo32 - uTotalOutBefore);
+      }
+
+      if(err == BZ_FINISH_OK)
+        err = ZIP_OK;
+#endif
+    }
+
+    if (err==Z_STREAM_END)
+        err=ZIP_OK; /* this is normal */
+
+    if ((zi->ci.pos_in_buffered_data>0) && (err==ZIP_OK))
+                {
+        if (zip64FlushWriteBuffer(zi)==ZIP_ERRNO)
+            err = ZIP_ERRNO;
+                }
+
+    if ((zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+    {
+        int tmp_err = deflateEnd(&zi->ci.stream);
+        if (err == ZIP_OK)
+            err = tmp_err;
+        zi->ci.stream_initialised = 0;
+    }
+#ifdef HAVE_BZIP2
+    else if((zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+    {
+      int tmperr = BZ2_bzCompressEnd(&zi->ci.bstream);
+                        if (err==ZIP_OK)
+                                err = tmperr;
+                        zi->ci.stream_initialised = 0;
+    }
+#endif
+
+    if (!zi->ci.raw)
+    {
+        crc32 = (uLong)zi->ci.crc32;
+        uncompressed_size = zi->ci.totalUncompressedData;
+    }
+    compressed_size = zi->ci.totalCompressedData;
+
+#    ifndef NOCRYPT
+    compressed_size += zi->ci.crypt_header_size;
+#    endif
+
+    // update Current Item crc and sizes,
+    if(compressed_size >= 0xffffffff || uncompressed_size >= 0xffffffff || zi->ci.pos_local_header >= 0xffffffff)
+    {
+      /*version Made by*/
+      zip64local_putValue_inmemory(zi->ci.central_header+4,(uLong)45,2);
+      /*version needed*/
+      zip64local_putValue_inmemory(zi->ci.central_header+6,(uLong)45,2);
+
+    }
+
+    zip64local_putValue_inmemory(zi->ci.central_header+16,crc32,4); /*crc*/
+
+
+    if(compressed_size >= 0xffffffff)
+      zip64local_putValue_inmemory(zi->ci.central_header+20, invalidValue,4); /*compr size*/
+    else
+      zip64local_putValue_inmemory(zi->ci.central_header+20, compressed_size,4); /*compr size*/
+
+    /// set internal file attributes field
+    if (zi->ci.stream.data_type == Z_ASCII)
+        zip64local_putValue_inmemory(zi->ci.central_header+36,(uLong)Z_ASCII,2);
+
+    if(uncompressed_size >= 0xffffffff)
+      zip64local_putValue_inmemory(zi->ci.central_header+24, invalidValue,4); /*uncompr size*/
+    else
+      zip64local_putValue_inmemory(zi->ci.central_header+24, uncompressed_size,4); /*uncompr size*/
+
+    // Add ZIP64 extra info field for uncompressed size
+    if(uncompressed_size >= 0xffffffff)
+      datasize += 8;
+
+    // Add ZIP64 extra info field for compressed size
+    if(compressed_size >= 0xffffffff)
+      datasize += 8;
+
+    // Add ZIP64 extra info field for relative offset to local file header of current file
+    if(zi->ci.pos_local_header >= 0xffffffff)
+      datasize += 8;
+
+    if(datasize > 0)
+    {
+      char* p = NULL;
+
+      if((uLong)(datasize + 4) > zi->ci.size_centralExtraFree)
+      {
+        // we can not write more data to the buffer that we have room for.
+        return ZIP_BADZIPFILE;
+      }
+
+      p = zi->ci.central_header + zi->ci.size_centralheader;
+
+      // Add Extra Information Header for 'ZIP64 information'
+      zip64local_putValue_inmemory(p, 0x0001, 2); // HeaderID
+      p += 2;
+      zip64local_putValue_inmemory(p, datasize, 2); // DataSize
+      p += 2;
+
+      if(uncompressed_size >= 0xffffffff)
+      {
+        zip64local_putValue_inmemory(p, uncompressed_size, 8);
+        p += 8;
+      }
+
+      if(compressed_size >= 0xffffffff)
+      {
+        zip64local_putValue_inmemory(p, compressed_size, 8);
+        p += 8;
+      }
+
+      if(zi->ci.pos_local_header >= 0xffffffff)
+      {
+        zip64local_putValue_inmemory(p, zi->ci.pos_local_header, 8);
+        p += 8;
+      }
+
+      // Update how much extra free space we got in the memory buffer
+      // and increase the centralheader size so the new ZIP64 fields are included
+      // ( 4 below is the size of HeaderID and DataSize field )
+      zi->ci.size_centralExtraFree -= datasize + 4;
+      zi->ci.size_centralheader += datasize + 4;
+
+      // Update the extra info size field
+      zi->ci.size_centralExtra += datasize + 4;
+      zip64local_putValue_inmemory(zi->ci.central_header+30,(uLong)zi->ci.size_centralExtra,2);
+    }
+
+    if (err==ZIP_OK)
+        err = add_data_in_datablock(&zi->central_dir, zi->ci.central_header, (uLong)zi->ci.size_centralheader);
+
+    free(zi->ci.central_header);
+
+    if (err==ZIP_OK)
+    {
+        // Update the LocalFileHeader with the new values.
+
+        ZPOS64_T cur_pos_inzip = ZTELL64(zi->z_filefunc,zi->filestream);
+
+        if (ZSEEK64(zi->z_filefunc,zi->filestream, zi->ci.pos_local_header + 14,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            err = ZIP_ERRNO;
+
+        if (err==ZIP_OK)
+            err = zip64local_putValue(&zi->z_filefunc,zi->filestream,crc32,4); /* crc 32, unknown */
+
+        if(uncompressed_size >= 0xffffffff || compressed_size >= 0xffffffff )
+        {
+          if(zi->ci.pos_zip64extrainfo > 0)
+          {
+            // Update the size in the ZIP64 extended field.
+            if (ZSEEK64(zi->z_filefunc,zi->filestream, zi->ci.pos_zip64extrainfo + 4,ZLIB_FILEFUNC_SEEK_SET)!=0)
+              err = ZIP_ERRNO;
+
+            if (err==ZIP_OK) /* compressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc, zi->filestream, uncompressed_size, 8);
+
+            if (err==ZIP_OK) /* uncompressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc, zi->filestream, compressed_size, 8);
+          }
+          else
+              err = ZIP_BADZIPFILE; // Caller passed zip64 = 0, so no room for zip64 info -> fatal
+        }
+        else
+        {
+          if (err==ZIP_OK) /* compressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc,zi->filestream,compressed_size,4);
+
+          if (err==ZIP_OK) /* uncompressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc,zi->filestream,uncompressed_size,4);
+        }
+
+        if (ZSEEK64(zi->z_filefunc,zi->filestream, cur_pos_inzip,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            err = ZIP_ERRNO;
+    }
+
+    zi->number_entry ++;
+    zi->in_opened_file_inzip = 0;
+
+    return err;
+}
+
+extern int ZEXPORT zipCloseFileInZip (zipFile file)
+{
+    return zipCloseFileInZipRaw (file,0,0);
+}
+
+int Write_Zip64EndOfCentralDirectoryLocator(zip64_internal* zi, ZPOS64_T zip64eocd_pos_inzip)
+{
+  int err = ZIP_OK;
+  ZPOS64_T pos = zip64eocd_pos_inzip - zi->add_position_when_writing_offset;
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)ZIP64ENDLOCHEADERMAGIC,4);
+
+  /*num disks*/
+    if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4);
+
+  /*relative offset*/
+    if (err==ZIP_OK) /* Relative offset to the Zip64EndOfCentralDirectory */
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream, pos,8);
+
+  /*total disks*/ /* Do not support spawning of disk so always say 1 here*/
+    if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)1,4);
+
+    return err;
+}
+
+int Write_Zip64EndOfCentralDirectoryRecord(zip64_internal* zi, uLong size_centraldir, ZPOS64_T centraldir_pos_inzip)
+{
+  int err = ZIP_OK;
+
+  uLong Zip64DataSize = 44;
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)ZIP64ENDHEADERMAGIC,4);
+
+  if (err==ZIP_OK) /* size of this 'zip64 end of central directory' */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(ZPOS64_T)Zip64DataSize,8); // why ZPOS64_T of this ?
+
+  if (err==ZIP_OK) /* version made by */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)45,2);
+
+  if (err==ZIP_OK) /* version needed */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)45,2);
+
+  if (err==ZIP_OK) /* number of this disk */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4);
+
+  if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4);
+
+  if (err==ZIP_OK) /* total number of entries in the central dir on this disk */
+    err = zip64local_putValue(&zi->z_filefunc, zi->filestream, zi->number_entry, 8);
+
+  if (err==ZIP_OK) /* total number of entries in the central dir */
+    err = zip64local_putValue(&zi->z_filefunc, zi->filestream, zi->number_entry, 8);
+
+  if (err==ZIP_OK) /* size of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(ZPOS64_T)size_centraldir,8);
+
+  if (err==ZIP_OK) /* offset of start of central directory with respect to the starting disk number */
+  {
+    ZPOS64_T pos = centraldir_pos_inzip - zi->add_position_when_writing_offset;
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream, (ZPOS64_T)pos,8);
+  }
+  return err;
+}
+int Write_EndOfCentralDirectoryRecord(zip64_internal* zi, uLong size_centraldir, ZPOS64_T centraldir_pos_inzip)
+{
+  int err = ZIP_OK;
+
+  /*signature*/
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)ENDHEADERMAGIC,4);
+
+  if (err==ZIP_OK) /* number of this disk */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,2);
+
+  if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,2);
+
+  if (err==ZIP_OK) /* total number of entries in the central dir on this disk */
+  {
+    {
+      if(zi->number_entry >= 0xFFFF)
+        err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xffff,2); // use value in ZIP64 record
+      else
+        err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->number_entry,2);
+    }
+  }
+
+  if (err==ZIP_OK) /* total number of entries in the central dir */
+  {
+    if(zi->number_entry >= 0xFFFF)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xffff,2); // use value in ZIP64 record
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->number_entry,2);
+  }
+
+  if (err==ZIP_OK) /* size of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_centraldir,4);
+
+  if (err==ZIP_OK) /* offset of start of central directory with respect to the starting disk number */
+  {
+    ZPOS64_T pos = centraldir_pos_inzip - zi->add_position_when_writing_offset;
+    if(pos >= 0xffffffff)
+    {
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream, (uLong)0xffffffff,4);
+    }
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream, (uLong)(centraldir_pos_inzip - zi->add_position_when_writing_offset),4);
+  }
+
+   return err;
+}
+
+int Write_GlobalComment(zip64_internal* zi, const char* global_comment)
+{
+  int err = ZIP_OK;
+  uInt size_global_comment = 0;
+
+  if(global_comment != NULL)
+    size_global_comment = (uInt)strlen(global_comment);
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_global_comment,2);
+
+  if (err == ZIP_OK && size_global_comment > 0)
+  {
+    if (ZWRITE64(zi->z_filefunc,zi->filestream, global_comment, size_global_comment) != size_global_comment)
+      err = ZIP_ERRNO;
+  }
+  return err;
+}
+
+extern int ZEXPORT zipClose (zipFile file, const char* global_comment)
+{
+    zip64_internal* zi;
+    int err = 0;
+    uLong size_centraldir = 0;
+    ZPOS64_T centraldir_pos_inzip;
+    ZPOS64_T pos;
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 1)
+    {
+        err = zipCloseFileInZip (file);
+    }
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+    if (global_comment==NULL)
+        global_comment = zi->globalcomment;
+#endif
+
+    centraldir_pos_inzip = ZTELL64(zi->z_filefunc,zi->filestream);
+
+    if (err==ZIP_OK)
+    {
+        linkedlist_datablock_internal* ldi = zi->central_dir.first_block;
+        while (ldi!=NULL)
+        {
+            if ((err==ZIP_OK) && (ldi->filled_in_this_block>0))
+            {
+                if (ZWRITE64(zi->z_filefunc,zi->filestream, ldi->data, ldi->filled_in_this_block) != ldi->filled_in_this_block)
+                    err = ZIP_ERRNO;
+            }
+
+            size_centraldir += ldi->filled_in_this_block;
+            ldi = ldi->next_datablock;
+        }
+    }
+    free_linkedlist(&(zi->central_dir));
+
+    pos = centraldir_pos_inzip - zi->add_position_when_writing_offset;
+    if(pos >= 0xffffffff || zi->number_entry > 0xFFFF)
+    {
+      ZPOS64_T Zip64EOCDpos = ZTELL64(zi->z_filefunc,zi->filestream);
+      Write_Zip64EndOfCentralDirectoryRecord(zi, size_centraldir, centraldir_pos_inzip);
+
+      Write_Zip64EndOfCentralDirectoryLocator(zi, Zip64EOCDpos);
+    }
+
+    if (err==ZIP_OK)
+      err = Write_EndOfCentralDirectoryRecord(zi, size_centraldir, centraldir_pos_inzip);
+
+    if(err == ZIP_OK)
+      err = Write_GlobalComment(zi, global_comment);
+
+    if (ZCLOSE64(zi->z_filefunc,zi->filestream) != 0)
+        if (err == ZIP_OK)
+            err = ZIP_ERRNO;
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+    TRYFREE(zi->globalcomment);
+#endif
+    TRYFREE(zi);
+
+    return err;
+}
+
+extern int ZEXPORT zipRemoveExtraInfoBlock (char* pData, int* dataLen, short sHeader)
+{
+  char* p = pData;
+  int size = 0;
+  char* pNewHeader;
+  char* pTmp;
+  short header;
+  short dataSize;
+
+  int retVal = ZIP_OK;
+
+  if(pData == NULL || *dataLen < 4)
+    return ZIP_PARAMERROR;
+
+  pNewHeader = (char*)ALLOC(*dataLen);
+  pTmp = pNewHeader;
+
+  while(p < (pData + *dataLen))
+  {
+    header = *(short*)p;
+    dataSize = *(((short*)p)+1);
+
+    if( header == sHeader ) // Header found.
+    {
+      p += dataSize + 4; // skip it. do not copy to temp buffer
+    }
+    else
+    {
+      // Extra Info block should not be removed, So copy it to the temp buffer.
+      memcpy(pTmp, p, dataSize + 4);
+      p += dataSize + 4;
+      size += dataSize + 4;
+    }
+
+  }
+
+  if(size < *dataLen)
+  {
+    // clean old extra info block.
+    memset(pData,0, *dataLen);
+
+    // copy the new extra info block over the old
+    if(size > 0)
+      memcpy(pData, pNewHeader, size);
+
+    // set the new extra info size
+    *dataLen = size;
+
+    retVal = ZIP_OK;
+  }
+  else
+    retVal = ZIP_ERRNO;
+
+  TRYFREE(pNewHeader);
+
+  return retVal;
+}
diff --git a/xs/src/png/zlib/contrib/minizip/zip.h b/xs/src/png/zlib/contrib/minizip/zip.h
new file mode 100644
index 000000000..8aaebb623
--- /dev/null
+++ b/xs/src/png/zlib/contrib/minizip/zip.h
@@ -0,0 +1,362 @@
+/* zip.h -- IO on .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         ---------------------------------------------------------------------------
+
+   Condition of use and distribution are the same than zlib :
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+        ---------------------------------------------------------------------------
+
+        Changes
+
+        See header of zip.h
+
+*/
+
+#ifndef _zip12_H
+#define _zip12_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//#define HAVE_BZIP2
+
+#ifndef _ZLIB_H
+#include "zlib.h"
+#endif
+
+#ifndef _ZLIBIOAPI_H
+#include "ioapi.h"
+#endif
+
+#ifdef HAVE_BZIP2
+#include "bzlib.h"
+#endif
+
+#define Z_BZIP2ED 12
+
+#if defined(STRICTZIP) || defined(STRICTZIPUNZIP)
+/* like the STRICT of WIN32, we define a pointer that cannot be converted
+    from (void*) without cast */
+typedef struct TagzipFile__ { int unused; } zipFile__;
+typedef zipFile__ *zipFile;
+#else
+typedef voidp zipFile;
+#endif
+
+#define ZIP_OK                          (0)
+#define ZIP_EOF                         (0)
+#define ZIP_ERRNO                       (Z_ERRNO)
+#define ZIP_PARAMERROR                  (-102)
+#define ZIP_BADZIPFILE                  (-103)
+#define ZIP_INTERNALERROR               (-104)
+
+#ifndef DEF_MEM_LEVEL
+#  if MAX_MEM_LEVEL >= 8
+#    define DEF_MEM_LEVEL 8
+#  else
+#    define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#  endif
+#endif
+/* default memLevel */
+
+/* tm_zip contain date/time info */
+typedef struct tm_zip_s
+{
+    uInt tm_sec;            /* seconds after the minute - [0,59] */
+    uInt tm_min;            /* minutes after the hour - [0,59] */
+    uInt tm_hour;           /* hours since midnight - [0,23] */
+    uInt tm_mday;           /* day of the month - [1,31] */
+    uInt tm_mon;            /* months since January - [0,11] */
+    uInt tm_year;           /* years - [1980..2044] */
+} tm_zip;
+
+typedef struct
+{
+    tm_zip      tmz_date;       /* date in understandable format           */
+    uLong       dosDate;       /* if dos_date == 0, tmu_date is used      */
+/*    uLong       flag;        */   /* general purpose bit flag        2 bytes */
+
+    uLong       internal_fa;    /* internal file attributes        2 bytes */
+    uLong       external_fa;    /* external file attributes        4 bytes */
+} zip_fileinfo;
+
+typedef const char* zipcharpc;
+
+
+#define APPEND_STATUS_CREATE        (0)
+#define APPEND_STATUS_CREATEAFTER   (1)
+#define APPEND_STATUS_ADDINZIP      (2)
+
+extern zipFile ZEXPORT zipOpen OF((const char *pathname, int append));
+extern zipFile ZEXPORT zipOpen64 OF((const void *pathname, int append));
+/*
+  Create a zipfile.
+     pathname contain on Windows XP a filename like "c:\\zlib\\zlib113.zip" or on
+       an Unix computer "zlib/zlib113.zip".
+     if the file pathname exist and append==APPEND_STATUS_CREATEAFTER, the zip
+       will be created at the end of the file.
+         (useful if the file contain a self extractor code)
+     if the file pathname exist and append==APPEND_STATUS_ADDINZIP, we will
+       add files in existing zip (be sure you don't add file that doesn't exist)
+     If the zipfile cannot be opened, the return value is NULL.
+     Else, the return value is a zipFile Handle, usable with other function
+       of this zip package.
+*/
+
+/* Note : there is no delete function into a zipfile.
+   If you want delete file into a zipfile, you must open a zipfile, and create another
+   Of couse, you can use RAW reading and writing to copy the file you did not want delte
+*/
+
+extern zipFile ZEXPORT zipOpen2 OF((const char *pathname,
+                                   int append,
+                                   zipcharpc* globalcomment,
+                                   zlib_filefunc_def* pzlib_filefunc_def));
+
+extern zipFile ZEXPORT zipOpen2_64 OF((const void *pathname,
+                                   int append,
+                                   zipcharpc* globalcomment,
+                                   zlib_filefunc64_def* pzlib_filefunc_def));
+
+extern int ZEXPORT zipOpenNewFileInZip OF((zipFile file,
+                       const char* filename,
+                       const zip_fileinfo* zipfi,
+                       const void* extrafield_local,
+                       uInt size_extrafield_local,
+                       const void* extrafield_global,
+                       uInt size_extrafield_global,
+                       const char* comment,
+                       int method,
+                       int level));
+
+extern int ZEXPORT zipOpenNewFileInZip64 OF((zipFile file,
+                       const char* filename,
+                       const zip_fileinfo* zipfi,
+                       const void* extrafield_local,
+                       uInt size_extrafield_local,
+                       const void* extrafield_global,
+                       uInt size_extrafield_global,
+                       const char* comment,
+                       int method,
+                       int level,
+                       int zip64));
+
+/*
+  Open a file in the ZIP for writing.
+  filename : the filename in zip (if NULL, '-' without quote will be used
+  *zipfi contain supplemental information
+  if extrafield_local!=NULL and size_extrafield_local>0, extrafield_local
+    contains the extrafield data the the local header
+  if extrafield_global!=NULL and size_extrafield_global>0, extrafield_global
+    contains the extrafield data the the local header
+  if comment != NULL, comment contain the comment string
+  method contain the compression method (0 for store, Z_DEFLATED for deflate)
+  level contain the level of compression (can be Z_DEFAULT_COMPRESSION)
+  zip64 is set to 1 if a zip64 extended information block should be added to the local file header.
+                    this MUST be '1' if the uncompressed size is >= 0xffffffff.
+
+*/
+
+
+extern int ZEXPORT zipOpenNewFileInZip2 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw));
+
+
+extern int ZEXPORT zipOpenNewFileInZip2_64 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int zip64));
+/*
+  Same than zipOpenNewFileInZip, except if raw=1, we write raw file
+ */
+
+extern int ZEXPORT zipOpenNewFileInZip3 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting));
+
+extern int ZEXPORT zipOpenNewFileInZip3_64 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting,
+                                            int zip64
+                                            ));
+
+/*
+  Same than zipOpenNewFileInZip2, except
+    windowBits,memLevel,,strategy : see parameter strategy in deflateInit2
+    password : crypting password (NULL for no crypting)
+    crcForCrypting : crc of file to compress (needed for crypting)
+ */
+
+extern int ZEXPORT zipOpenNewFileInZip4 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting,
+                                            uLong versionMadeBy,
+                                            uLong flagBase
+                                            ));
+
+
+extern int ZEXPORT zipOpenNewFileInZip4_64 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting,
+                                            uLong versionMadeBy,
+                                            uLong flagBase,
+                                            int zip64
+                                            ));
+/*
+  Same than zipOpenNewFileInZip4, except
+    versionMadeBy : value for Version made by field
+    flag : value for flag field (compression level info will be added)
+ */
+
+
+extern int ZEXPORT zipWriteInFileInZip OF((zipFile file,
+                       const void* buf,
+                       unsigned len));
+/*
+  Write data in the zipfile
+*/
+
+extern int ZEXPORT zipCloseFileInZip OF((zipFile file));
+/*
+  Close the current file in the zipfile
+*/
+
+extern int ZEXPORT zipCloseFileInZipRaw OF((zipFile file,
+                                            uLong uncompressed_size,
+                                            uLong crc32));
+
+extern int ZEXPORT zipCloseFileInZipRaw64 OF((zipFile file,
+                                            ZPOS64_T uncompressed_size,
+                                            uLong crc32));
+
+/*
+  Close the current file in the zipfile, for file opened with
+    parameter raw=1 in zipOpenNewFileInZip2
+  uncompressed_size and crc32 are value for the uncompressed size
+*/
+
+extern int ZEXPORT zipClose OF((zipFile file,
+                const char* global_comment));
+/*
+  Close the zipfile
+*/
+
+
+extern int ZEXPORT zipRemoveExtraInfoBlock OF((char* pData, int* dataLen, short sHeader));
+/*
+  zipRemoveExtraInfoBlock -  Added by Mathias Svensson
+
+  Remove extra information block from a extra information data for the local file header or central directory header
+
+  It is needed to remove ZIP64 extra information blocks when before data is written if using RAW mode.
+
+  0x0001 is the signature header for the ZIP64 extra information blocks
+
+  usage.
+                        Remove ZIP64 Extra information from a central director extra field data
+              zipRemoveExtraInfoBlock(pCenDirExtraFieldData, &nCenDirExtraFieldDataLen, 0x0001);
+
+                        Remove ZIP64 Extra information from a Local File Header extra field data
+        zipRemoveExtraInfoBlock(pLocalHeaderExtraFieldData, &nLocalHeaderExtraFieldDataLen, 0x0001);
+*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _zip64_H */
diff --git a/xs/src/png/zlib/contrib/pascal/example.pas b/xs/src/png/zlib/contrib/pascal/example.pas
new file mode 100644
index 000000000..5518b36a7
--- /dev/null
+++ b/xs/src/png/zlib/contrib/pascal/example.pas
@@ -0,0 +1,599 @@
+(* example.c -- usage example of the zlib compression library
+ * Copyright (C) 1995-2003 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Pascal translation
+ * Copyright (C) 1998 by Jacques Nomssi Nzali.
+ * For conditions of distribution and use, see copyright notice in readme.txt
+ *
+ * Adaptation to the zlibpas interface
+ * Copyright (C) 2003 by Cosmin Truta.
+ * For conditions of distribution and use, see copyright notice in readme.txt
+ *)
+
+program example;
+
+{$DEFINE TEST_COMPRESS}
+{DO NOT $DEFINE TEST_GZIO}
+{$DEFINE TEST_DEFLATE}
+{$DEFINE TEST_INFLATE}
+{$DEFINE TEST_FLUSH}
+{$DEFINE TEST_SYNC}
+{$DEFINE TEST_DICT}
+
+uses SysUtils, zlibpas;
+
+const TESTFILE = 'foo.gz';
+
+(* "hello world" would be more standard, but the repeated "hello"
+ * stresses the compression code better, sorry...
+ *)
+const hello: PChar = 'hello, hello!';
+
+const dictionary: PChar = 'hello';
+
+var dictId: LongInt; (* Adler32 value of the dictionary *)
+
+procedure CHECK_ERR(err: Integer; msg: String);
+begin
+  if err <> Z_OK then
+  begin
+    WriteLn(msg, ' error: ', err);
+    Halt(1);
+  end;
+end;
+
+procedure EXIT_ERR(const msg: String);
+begin
+  WriteLn('Error: ', msg);
+  Halt(1);
+end;
+
+(* ===========================================================================
+ * Test compress and uncompress
+ *)
+{$IFDEF TEST_COMPRESS}
+procedure test_compress(compr: Pointer; comprLen: LongInt;
+                        uncompr: Pointer; uncomprLen: LongInt);
+var err: Integer;
+    len: LongInt;
+begin
+  len := StrLen(hello)+1;
+
+  err := compress(compr, comprLen, hello, len);
+  CHECK_ERR(err, 'compress');
+
+  StrCopy(PChar(uncompr), 'garbage');
+
+  err := uncompress(uncompr, uncomprLen, compr, comprLen);
+  CHECK_ERR(err, 'uncompress');
+
+  if StrComp(PChar(uncompr), hello) <> 0 then
+    EXIT_ERR('bad uncompress')
+  else
+    WriteLn('uncompress(): ', PChar(uncompr));
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test read/write of .gz files
+ *)
+{$IFDEF TEST_GZIO}
+procedure test_gzio(const fname: PChar; (* compressed file name *)
+                    uncompr: Pointer;
+                    uncomprLen: LongInt);
+var err: Integer;
+    len: Integer;
+    zfile: gzFile;
+    pos: LongInt;
+begin
+  len := StrLen(hello)+1;
+
+  zfile := gzopen(fname, 'wb');
+  if zfile = NIL then
+  begin
+    WriteLn('gzopen error');
+    Halt(1);
+  end;
+  gzputc(zfile, 'h');
+  if gzputs(zfile, 'ello') <> 4 then
+  begin
+    WriteLn('gzputs err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  {$IFDEF GZ_FORMAT_STRING}
+  if gzprintf(zfile, ', %s!', 'hello') <> 8 then
+  begin
+    WriteLn('gzprintf err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  {$ELSE}
+  if gzputs(zfile, ', hello!') <> 8 then
+  begin
+    WriteLn('gzputs err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  {$ENDIF}
+  gzseek(zfile, 1, SEEK_CUR); (* add one zero byte *)
+  gzclose(zfile);
+
+  zfile := gzopen(fname, 'rb');
+  if zfile = NIL then
+  begin
+    WriteLn('gzopen error');
+    Halt(1);
+  end;
+
+  StrCopy(PChar(uncompr), 'garbage');
+
+  if gzread(zfile, uncompr, uncomprLen) <> len then
+  begin
+    WriteLn('gzread err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  if StrComp(PChar(uncompr), hello) <> 0 then
+  begin
+    WriteLn('bad gzread: ', PChar(uncompr));
+    Halt(1);
+  end
+  else
+    WriteLn('gzread(): ', PChar(uncompr));
+
+  pos := gzseek(zfile, -8, SEEK_CUR);
+  if (pos <> 6) or (gztell(zfile) <> pos) then
+  begin
+    WriteLn('gzseek error, pos=', pos, ', gztell=', gztell(zfile));
+    Halt(1);
+  end;
+
+  if gzgetc(zfile) <> ' ' then
+  begin
+    WriteLn('gzgetc error');
+    Halt(1);
+  end;
+
+  if gzungetc(' ', zfile) <> ' ' then
+  begin
+    WriteLn('gzungetc error');
+    Halt(1);
+  end;
+
+  gzgets(zfile, PChar(uncompr), uncomprLen);
+  uncomprLen := StrLen(PChar(uncompr));
+  if uncomprLen <> 7 then (* " hello!" *)
+  begin
+    WriteLn('gzgets err after gzseek: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  if StrComp(PChar(uncompr), hello + 6) <> 0 then
+  begin
+    WriteLn('bad gzgets after gzseek');
+    Halt(1);
+  end
+  else
+    WriteLn('gzgets() after gzseek: ', PChar(uncompr));
+
+  gzclose(zfile);
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with small buffers
+ *)
+{$IFDEF TEST_DEFLATE}
+procedure test_deflate(compr: Pointer; comprLen: LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+    len: LongInt;
+begin
+  len := StrLen(hello)+1;
+
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_DEFAULT_COMPRESSION);
+  CHECK_ERR(err, 'deflateInit');
+
+  c_stream.next_in := hello;
+  c_stream.next_out := compr;
+
+  while (c_stream.total_in <> len) and
+        (c_stream.total_out < comprLen) do
+  begin
+    c_stream.avail_out := 1; { force small buffers }
+    c_stream.avail_in := 1;
+    err := deflate(c_stream, Z_NO_FLUSH);
+    CHECK_ERR(err, 'deflate');
+  end;
+
+  (* Finish the stream, still forcing small buffers: *)
+  while TRUE do
+  begin
+    c_stream.avail_out := 1;
+    err := deflate(c_stream, Z_FINISH);
+    if err = Z_STREAM_END then
+      break;
+    CHECK_ERR(err, 'deflate');
+  end;
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflate with small buffers
+ *)
+{$IFDEF TEST_INFLATE}
+procedure test_inflate(compr: Pointer; comprLen : LongInt;
+                       uncompr: Pointer; uncomprLen : LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := 0;
+  d_stream.next_out := uncompr;
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  while (d_stream.total_out < uncomprLen) and
+        (d_stream.total_in < comprLen) do
+  begin
+    d_stream.avail_out := 1; (* force small buffers *)
+    d_stream.avail_in := 1;
+    err := inflate(d_stream, Z_NO_FLUSH);
+    if err = Z_STREAM_END then
+      break;
+    CHECK_ERR(err, 'inflate');
+  end;
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  if StrComp(PChar(uncompr), hello) <> 0 then
+    EXIT_ERR('bad inflate')
+  else
+    WriteLn('inflate(): ', PChar(uncompr));
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with large buffers and dynamic change of compression level
+ *)
+{$IFDEF TEST_DEFLATE}
+procedure test_large_deflate(compr: Pointer; comprLen: LongInt;
+                             uncompr: Pointer; uncomprLen: LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+begin
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_BEST_SPEED);
+  CHECK_ERR(err, 'deflateInit');
+
+  c_stream.next_out := compr;
+  c_stream.avail_out := Integer(comprLen);
+
+  (* At this point, uncompr is still mostly zeroes, so it should compress
+   * very well:
+   *)
+  c_stream.next_in := uncompr;
+  c_stream.avail_in := Integer(uncomprLen);
+  err := deflate(c_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'deflate');
+  if c_stream.avail_in <> 0 then
+    EXIT_ERR('deflate not greedy');
+
+  (* Feed in already compressed data and switch to no compression: *)
+  deflateParams(c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);
+  c_stream.next_in := compr;
+  c_stream.avail_in := Integer(comprLen div 2);
+  err := deflate(c_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'deflate');
+
+  (* Switch back to compressing mode: *)
+  deflateParams(c_stream, Z_BEST_COMPRESSION, Z_FILTERED);
+  c_stream.next_in := uncompr;
+  c_stream.avail_in := Integer(uncomprLen);
+  err := deflate(c_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'deflate');
+
+  err := deflate(c_stream, Z_FINISH);
+  if err <> Z_STREAM_END then
+    EXIT_ERR('deflate should report Z_STREAM_END');
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflate with large buffers
+ *)
+{$IFDEF TEST_INFLATE}
+procedure test_large_inflate(compr: Pointer; comprLen: LongInt;
+                             uncompr: Pointer; uncomprLen: LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := Integer(comprLen);
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  while TRUE do
+  begin
+    d_stream.next_out := uncompr;            (* discard the output *)
+    d_stream.avail_out := Integer(uncomprLen);
+    err := inflate(d_stream, Z_NO_FLUSH);
+    if err = Z_STREAM_END then
+      break;
+    CHECK_ERR(err, 'large inflate');
+  end;
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  if d_stream.total_out <> 2 * uncomprLen + comprLen div 2 then
+  begin
+    WriteLn('bad large inflate: ', d_stream.total_out);
+    Halt(1);
+  end
+  else
+    WriteLn('large_inflate(): OK');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with full flush
+ *)
+{$IFDEF TEST_FLUSH}
+procedure test_flush(compr: Pointer; var comprLen : LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+    len: Integer;
+begin
+  len := StrLen(hello)+1;
+
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_DEFAULT_COMPRESSION);
+  CHECK_ERR(err, 'deflateInit');
+
+  c_stream.next_in := hello;
+  c_stream.next_out := compr;
+  c_stream.avail_in := 3;
+  c_stream.avail_out := Integer(comprLen);
+  err := deflate(c_stream, Z_FULL_FLUSH);
+  CHECK_ERR(err, 'deflate');
+
+  Inc(PByteArray(compr)^[3]); (* force an error in first compressed block *)
+  c_stream.avail_in := len - 3;
+
+  err := deflate(c_stream, Z_FINISH);
+  if err <> Z_STREAM_END then
+    CHECK_ERR(err, 'deflate');
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+
+  comprLen := c_stream.total_out;
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflateSync()
+ *)
+{$IFDEF TEST_SYNC}
+procedure test_sync(compr: Pointer; comprLen: LongInt;
+                    uncompr: Pointer; uncomprLen : LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := 2; (* just read the zlib header *)
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  d_stream.next_out := uncompr;
+  d_stream.avail_out := Integer(uncomprLen);
+
+  inflate(d_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'inflate');
+
+  d_stream.avail_in := Integer(comprLen-2);   (* read all compressed data *)
+  err := inflateSync(d_stream);               (* but skip the damaged part *)
+  CHECK_ERR(err, 'inflateSync');
+
+  err := inflate(d_stream, Z_FINISH);
+  if err <> Z_DATA_ERROR then
+    EXIT_ERR('inflate should report DATA_ERROR');
+    (* Because of incorrect adler32 *)
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  WriteLn('after inflateSync(): hel', PChar(uncompr));
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with preset dictionary
+ *)
+{$IFDEF TEST_DICT}
+procedure test_dict_deflate(compr: Pointer; comprLen: LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+begin
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_BEST_COMPRESSION);
+  CHECK_ERR(err, 'deflateInit');
+
+  err := deflateSetDictionary(c_stream, dictionary, StrLen(dictionary));
+  CHECK_ERR(err, 'deflateSetDictionary');
+
+  dictId := c_stream.adler;
+  c_stream.next_out := compr;
+  c_stream.avail_out := Integer(comprLen);
+
+  c_stream.next_in := hello;
+  c_stream.avail_in := StrLen(hello)+1;
+
+  err := deflate(c_stream, Z_FINISH);
+  if err <> Z_STREAM_END then
+    EXIT_ERR('deflate should report Z_STREAM_END');
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflate with a preset dictionary
+ *)
+{$IFDEF TEST_DICT}
+procedure test_dict_inflate(compr: Pointer; comprLen: LongInt;
+                            uncompr: Pointer; uncomprLen: LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := Integer(comprLen);
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  d_stream.next_out := uncompr;
+  d_stream.avail_out := Integer(uncomprLen);
+
+  while TRUE do
+  begin
+    err := inflate(d_stream, Z_NO_FLUSH);
+    if err = Z_STREAM_END then
+      break;
+    if err = Z_NEED_DICT then
+    begin
+      if d_stream.adler <> dictId then
+        EXIT_ERR('unexpected dictionary');
+      err := inflateSetDictionary(d_stream, dictionary, StrLen(dictionary));
+    end;
+    CHECK_ERR(err, 'inflate with dict');
+  end;
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  if StrComp(PChar(uncompr), hello) <> 0 then
+    EXIT_ERR('bad inflate with dict')
+  else
+    WriteLn('inflate with dictionary: ', PChar(uncompr));
+end;
+{$ENDIF}
+
+var compr, uncompr: Pointer;
+    comprLen, uncomprLen: LongInt;
+
+begin
+  if zlibVersion^ <> ZLIB_VERSION[1] then
+    EXIT_ERR('Incompatible zlib version');
+
+  WriteLn('zlib version: ', zlibVersion);
+  WriteLn('zlib compile flags: ', Format('0x%x', [zlibCompileFlags]));
+
+  comprLen := 10000 * SizeOf(Integer); (* don't overflow on MSDOS *)
+  uncomprLen := comprLen;
+  GetMem(compr, comprLen);
+  GetMem(uncompr, uncomprLen);
+  if (compr = NIL) or (uncompr = NIL) then
+    EXIT_ERR('Out of memory');
+  (* compr and uncompr are cleared to avoid reading uninitialized
+   * data and to ensure that uncompr compresses well.
+   *)
+  FillChar(compr^, comprLen, 0);
+  FillChar(uncompr^, uncomprLen, 0);
+
+  {$IFDEF TEST_COMPRESS}
+  WriteLn('** Testing compress');
+  test_compress(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_GZIO}
+  WriteLn('** Testing gzio');
+  if ParamCount >= 1 then
+    test_gzio(ParamStr(1), uncompr, uncomprLen)
+  else
+    test_gzio(TESTFILE, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_DEFLATE}
+  WriteLn('** Testing deflate with small buffers');
+  test_deflate(compr, comprLen);
+  {$ENDIF}
+  {$IFDEF TEST_INFLATE}
+  WriteLn('** Testing inflate with small buffers');
+  test_inflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_DEFLATE}
+  WriteLn('** Testing deflate with large buffers');
+  test_large_deflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+  {$IFDEF TEST_INFLATE}
+  WriteLn('** Testing inflate with large buffers');
+  test_large_inflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_FLUSH}
+  WriteLn('** Testing deflate with full flush');
+  test_flush(compr, comprLen);
+  {$ENDIF}
+  {$IFDEF TEST_SYNC}
+  WriteLn('** Testing inflateSync');
+  test_sync(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+  comprLen := uncomprLen;
+
+  {$IFDEF TEST_DICT}
+  WriteLn('** Testing deflate and inflate with preset dictionary');
+  test_dict_deflate(compr, comprLen);
+  test_dict_inflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  FreeMem(compr, comprLen);
+  FreeMem(uncompr, uncomprLen);
+end.
diff --git a/xs/src/png/zlib/contrib/pascal/readme.txt b/xs/src/png/zlib/contrib/pascal/readme.txt
new file mode 100644
index 000000000..60e87c8a3
--- /dev/null
+++ b/xs/src/png/zlib/contrib/pascal/readme.txt
@@ -0,0 +1,76 @@
+
+This directory contains a Pascal (Delphi, Kylix) interface to the
+zlib data compression library.
+
+
+Directory listing
+=================
+
+zlibd32.mak     makefile for Borland C++
+example.pas     usage example of zlib
+zlibpas.pas     the Pascal interface to zlib
+readme.txt      this file
+
+
+Compatibility notes
+===================
+
+- Although the name "zlib" would have been more normal for the
+  zlibpas unit, this name is already taken by Borland's ZLib unit.
+  This is somehow unfortunate, because that unit is not a genuine
+  interface to the full-fledged zlib functionality, but a suite of
+  class wrappers around zlib streams.  Other essential features,
+  such as checksums, are missing.
+  It would have been more appropriate for that unit to have a name
+  like "ZStreams", or something similar.
+
+- The C and zlib-supplied types int, uInt, long, uLong, etc. are
+  translated directly into Pascal types of similar sizes (Integer,
+  LongInt, etc.), to avoid namespace pollution.  In particular,
+  there is no conversion of unsigned int into a Pascal unsigned
+  integer.  The Word type is non-portable and has the same size
+  (16 bits) both in a 16-bit and in a 32-bit environment, unlike
+  Integer.  Even if there is a 32-bit Cardinal type, there is no
+  real need for unsigned int in zlib under a 32-bit environment.
+
+- Except for the callbacks, the zlib function interfaces are
+  assuming the calling convention normally used in Pascal
+  (__pascal for DOS and Windows16, __fastcall for Windows32).
+  Since the cdecl keyword is used, the old Turbo Pascal does
+  not work with this interface.
+
+- The gz* function interfaces are not translated, to avoid
+  interfacing problems with the C runtime library.  Besides,
+    gzprintf(gzFile file, const char *format, ...)
+  cannot be translated into Pascal.
+
+
+Legal issues
+============
+
+The zlibpas interface is:
+  Copyright (C) 1995-2003 Jean-loup Gailly and Mark Adler.
+  Copyright (C) 1998 by Bob Dellaca.
+  Copyright (C) 2003 by Cosmin Truta.
+
+The example program is:
+  Copyright (C) 1995-2003 by Jean-loup Gailly.
+  Copyright (C) 1998,1999,2000 by Jacques Nomssi Nzali.
+  Copyright (C) 2003 by Cosmin Truta.
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
diff --git a/xs/src/png/zlib/contrib/pascal/zlibd32.mak b/xs/src/png/zlib/contrib/pascal/zlibd32.mak
new file mode 100644
index 000000000..9bb00b7cc
--- /dev/null
+++ b/xs/src/png/zlib/contrib/pascal/zlibd32.mak
@@ -0,0 +1,99 @@
+# Makefile for zlib
+# For use with Delphi and C++ Builder under Win32
+# Updated for zlib 1.2.x by Cosmin Truta
+
+# ------------ Borland C++ ------------
+
+# This project uses the Delphi (fastcall/register) calling convention:
+LOC = -DZEXPORT=__fastcall -DZEXPORTVA=__cdecl
+
+CC = bcc32
+LD = bcc32
+AR = tlib
+# do not use "-pr" in CFLAGS
+CFLAGS = -a -d -k- -O2 $(LOC)
+LDFLAGS =
+
+
+# variables
+ZLIB_LIB = zlib.lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# For the sake of the old Borland make,
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+
+
+# testing
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+
+# cleanup
+clean:
+	-del *.obj
+	-del *.exe
+	-del *.lib
+	-del *.tds
+	-del zlib.bak
+	-del foo.gz
+
diff --git a/xs/src/png/zlib/contrib/pascal/zlibpas.pas b/xs/src/png/zlib/contrib/pascal/zlibpas.pas
new file mode 100644
index 000000000..a0dff11b5
--- /dev/null
+++ b/xs/src/png/zlib/contrib/pascal/zlibpas.pas
@@ -0,0 +1,276 @@
+(* zlibpas -- Pascal interface to the zlib data compression library
+ *
+ * Copyright (C) 2003 Cosmin Truta.
+ * Derived from original sources by Bob Dellaca.
+ * For conditions of distribution and use, see copyright notice in readme.txt
+ *)
+
+unit zlibpas;
+
+interface
+
+const
+  ZLIB_VERSION = '1.2.11';
+  ZLIB_VERNUM  = $12a0;
+
+type
+  alloc_func = function(opaque: Pointer; items, size: Integer): Pointer;
+                 cdecl;
+  free_func  = procedure(opaque, address: Pointer);
+                 cdecl;
+
+  in_func    = function(opaque: Pointer; var buf: PByte): Integer;
+                 cdecl;
+  out_func   = function(opaque: Pointer; buf: PByte; size: Integer): Integer;
+                 cdecl;
+
+  z_streamp = ^z_stream;
+  z_stream = packed record
+    next_in: PChar;       (* next input byte *)
+    avail_in: Integer;    (* number of bytes available at next_in *)
+    total_in: LongInt;    (* total nb of input bytes read so far *)
+
+    next_out: PChar;      (* next output byte should be put there *)
+    avail_out: Integer;   (* remaining free space at next_out *)
+    total_out: LongInt;   (* total nb of bytes output so far *)
+
+    msg: PChar;           (* last error message, NULL if no error *)
+    state: Pointer;       (* not visible by applications *)
+
+    zalloc: alloc_func;   (* used to allocate the internal state *)
+    zfree: free_func;     (* used to free the internal state *)
+    opaque: Pointer;      (* private data object passed to zalloc and zfree *)
+
+    data_type: Integer;   (* best guess about the data type: ascii or binary *)
+    adler: LongInt;       (* adler32 value of the uncompressed data *)
+    reserved: LongInt;    (* reserved for future use *)
+  end;
+
+  gz_headerp = ^gz_header;
+  gz_header = packed record
+    text: Integer;        (* true if compressed data believed to be text *)
+    time: LongInt;        (* modification time *)
+    xflags: Integer;      (* extra flags (not used when writing a gzip file) *)
+    os: Integer;          (* operating system *)
+    extra: PChar;         (* pointer to extra field or Z_NULL if none *)
+    extra_len: Integer;   (* extra field length (valid if extra != Z_NULL) *)
+    extra_max: Integer;   (* space at extra (only when reading header) *)
+    name: PChar;          (* pointer to zero-terminated file name or Z_NULL *)
+    name_max: Integer;    (* space at name (only when reading header) *)
+    comment: PChar;       (* pointer to zero-terminated comment or Z_NULL *)
+    comm_max: Integer;    (* space at comment (only when reading header) *)
+    hcrc: Integer;        (* true if there was or will be a header crc *)
+    done: Integer;        (* true when done reading gzip header *)
+  end;
+
+(* constants *)
+const
+  Z_NO_FLUSH      = 0;
+  Z_PARTIAL_FLUSH = 1;
+  Z_SYNC_FLUSH    = 2;
+  Z_FULL_FLUSH    = 3;
+  Z_FINISH        = 4;
+  Z_BLOCK         = 5;
+  Z_TREES         = 6;
+
+  Z_OK            =  0;
+  Z_STREAM_END    =  1;
+  Z_NEED_DICT     =  2;
+  Z_ERRNO         = -1;
+  Z_STREAM_ERROR  = -2;
+  Z_DATA_ERROR    = -3;
+  Z_MEM_ERROR     = -4;
+  Z_BUF_ERROR     = -5;
+  Z_VERSION_ERROR = -6;
+
+  Z_NO_COMPRESSION       =  0;
+  Z_BEST_SPEED           =  1;
+  Z_BEST_COMPRESSION     =  9;
+  Z_DEFAULT_COMPRESSION  = -1;
+
+  Z_FILTERED            = 1;
+  Z_HUFFMAN_ONLY        = 2;
+  Z_RLE                 = 3;
+  Z_FIXED               = 4;
+  Z_DEFAULT_STRATEGY    = 0;
+
+  Z_BINARY   = 0;
+  Z_TEXT     = 1;
+  Z_ASCII    = 1;
+  Z_UNKNOWN  = 2;
+
+  Z_DEFLATED = 8;
+
+(* basic functions *)
+function zlibVersion: PChar;
+function deflateInit(var strm: z_stream; level: Integer): Integer;
+function deflate(var strm: z_stream; flush: Integer): Integer;
+function deflateEnd(var strm: z_stream): Integer;
+function inflateInit(var strm: z_stream): Integer;
+function inflate(var strm: z_stream; flush: Integer): Integer;
+function inflateEnd(var strm: z_stream): Integer;
+
+(* advanced functions *)
+function deflateInit2(var strm: z_stream; level, method, windowBits,
+                      memLevel, strategy: Integer): Integer;
+function deflateSetDictionary(var strm: z_stream; const dictionary: PChar;
+                              dictLength: Integer): Integer;
+function deflateCopy(var dest, source: z_stream): Integer;
+function deflateReset(var strm: z_stream): Integer;
+function deflateParams(var strm: z_stream; level, strategy: Integer): Integer;
+function deflateTune(var strm: z_stream; good_length, max_lazy, nice_length, max_chain: Integer): Integer;
+function deflateBound(var strm: z_stream; sourceLen: LongInt): LongInt;
+function deflatePending(var strm: z_stream; var pending: Integer; var bits: Integer): Integer;
+function deflatePrime(var strm: z_stream; bits, value: Integer): Integer;
+function deflateSetHeader(var strm: z_stream; head: gz_header): Integer;
+function inflateInit2(var strm: z_stream; windowBits: Integer): Integer;
+function inflateSetDictionary(var strm: z_stream; const dictionary: PChar;
+                              dictLength: Integer): Integer;
+function inflateSync(var strm: z_stream): Integer;
+function inflateCopy(var dest, source: z_stream): Integer;
+function inflateReset(var strm: z_stream): Integer;
+function inflateReset2(var strm: z_stream; windowBits: Integer): Integer;
+function inflatePrime(var strm: z_stream; bits, value: Integer): Integer;
+function inflateMark(var strm: z_stream): LongInt;
+function inflateGetHeader(var strm: z_stream; var head: gz_header): Integer;
+function inflateBackInit(var strm: z_stream;
+                         windowBits: Integer; window: PChar): Integer;
+function inflateBack(var strm: z_stream; in_fn: in_func; in_desc: Pointer;
+                     out_fn: out_func; out_desc: Pointer): Integer;
+function inflateBackEnd(var strm: z_stream): Integer;
+function zlibCompileFlags: LongInt;
+
+(* utility functions *)
+function compress(dest: PChar; var destLen: LongInt;
+                  const source: PChar; sourceLen: LongInt): Integer;
+function compress2(dest: PChar; var destLen: LongInt;
+                  const source: PChar; sourceLen: LongInt;
+                  level: Integer): Integer;
+function compressBound(sourceLen: LongInt): LongInt;
+function uncompress(dest: PChar; var destLen: LongInt;
+                    const source: PChar; sourceLen: LongInt): Integer;
+
+(* checksum functions *)
+function adler32(adler: LongInt; const buf: PChar; len: Integer): LongInt;
+function adler32_combine(adler1, adler2, len2: LongInt): LongInt;
+function crc32(crc: LongInt; const buf: PChar; len: Integer): LongInt;
+function crc32_combine(crc1, crc2, len2: LongInt): LongInt;
+
+(* various hacks, don't look :) *)
+function deflateInit_(var strm: z_stream; level: Integer;
+                      const version: PChar; stream_size: Integer): Integer;
+function inflateInit_(var strm: z_stream; const version: PChar;
+                      stream_size: Integer): Integer;
+function deflateInit2_(var strm: z_stream;
+                       level, method, windowBits, memLevel, strategy: Integer;
+                       const version: PChar; stream_size: Integer): Integer;
+function inflateInit2_(var strm: z_stream; windowBits: Integer;
+                       const version: PChar; stream_size: Integer): Integer;
+function inflateBackInit_(var strm: z_stream;
+                          windowBits: Integer; window: PChar;
+                          const version: PChar; stream_size: Integer): Integer;
+
+
+implementation
+
+{$L adler32.obj}
+{$L compress.obj}
+{$L crc32.obj}
+{$L deflate.obj}
+{$L infback.obj}
+{$L inffast.obj}
+{$L inflate.obj}
+{$L inftrees.obj}
+{$L trees.obj}
+{$L uncompr.obj}
+{$L zutil.obj}
+
+function adler32; external;
+function adler32_combine; external;
+function compress; external;
+function compress2; external;
+function compressBound; external;
+function crc32; external;
+function crc32_combine; external;
+function deflate; external;
+function deflateBound; external;
+function deflateCopy; external;
+function deflateEnd; external;
+function deflateInit_; external;
+function deflateInit2_; external;
+function deflateParams; external;
+function deflatePending; external;
+function deflatePrime; external;
+function deflateReset; external;
+function deflateSetDictionary; external;
+function deflateSetHeader; external;
+function deflateTune; external;
+function inflate; external;
+function inflateBack; external;
+function inflateBackEnd; external;
+function inflateBackInit_; external;
+function inflateCopy; external;
+function inflateEnd; external;
+function inflateGetHeader; external;
+function inflateInit_; external;
+function inflateInit2_; external;
+function inflateMark; external;
+function inflatePrime; external;
+function inflateReset; external;
+function inflateReset2; external;
+function inflateSetDictionary; external;
+function inflateSync; external;
+function uncompress; external;
+function zlibCompileFlags; external;
+function zlibVersion; external;
+
+function deflateInit(var strm: z_stream; level: Integer): Integer;
+begin
+  Result := deflateInit_(strm, level, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function deflateInit2(var strm: z_stream; level, method, windowBits, memLevel,
+                      strategy: Integer): Integer;
+begin
+  Result := deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
+                          ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateInit(var strm: z_stream): Integer;
+begin
+  Result := inflateInit_(strm, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateInit2(var strm: z_stream; windowBits: Integer): Integer;
+begin
+  Result := inflateInit2_(strm, windowBits, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateBackInit(var strm: z_stream;
+                         windowBits: Integer; window: PChar): Integer;
+begin
+  Result := inflateBackInit_(strm, windowBits, window,
+                             ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function _malloc(Size: Integer): Pointer; cdecl;
+begin
+  GetMem(Result, Size);
+end;
+
+procedure _free(Block: Pointer); cdecl;
+begin
+  FreeMem(Block);
+end;
+
+procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl;
+begin
+  FillChar(P^, count, B);
+end;
+
+procedure _memcpy(dest, source: Pointer; count: Integer); cdecl;
+begin
+  Move(source^, dest^, count);
+end;
+
+end.
diff --git a/xs/src/png/zlib/contrib/puff/Makefile b/xs/src/png/zlib/contrib/puff/Makefile
new file mode 100644
index 000000000..0e2594c80
--- /dev/null
+++ b/xs/src/png/zlib/contrib/puff/Makefile
@@ -0,0 +1,42 @@
+CFLAGS=-O
+
+puff: puff.o pufftest.o
+
+puff.o: puff.h
+
+pufftest.o: puff.h
+
+test: puff
+	puff zeros.raw
+
+puft: puff.c puff.h pufftest.o
+	cc -fprofile-arcs -ftest-coverage -o puft puff.c pufftest.o
+
+# puff full coverage test (should say 100%)
+cov: puft
+	@rm -f *.gcov *.gcda
+	@puft -w zeros.raw 2>&1 | cat > /dev/null
+	@echo '04' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '00 00 00 00 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 254
+	@echo '00 01 00 fe ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '01 01 00 fe ff 0a' | xxd -r -p | puft -f 2>&1 | cat > /dev/null
+	@echo '02 7e ff ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 246
+	@echo '02' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '04 80 49 92 24 49 92 24 0f b4 ff ff c3 04' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '04 80 49 92 24 49 92 24 71 ff ff 93 11 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 249
+	@echo '04 c0 81 08 00 00 00 00 20 7f eb 0b 00 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 246
+	@echo '0b 00 00' | xxd -r -p | puft -f 2>&1 | cat > /dev/null
+	@echo '1a 07' | xxd -r -p | puft 2> /dev/null || test $$? -eq 246
+	@echo '0c c0 81 00 00 00 00 00 90 ff 6b 04' | xxd -r -p | puft 2> /dev/null || test $$? -eq 245
+	@puft -f zeros.raw 2>&1 | cat > /dev/null
+	@echo 'fc 00 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 253
+	@echo '04 00 fe ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 252
+	@echo '04 00 24 49' | xxd -r -p | puft 2> /dev/null || test $$? -eq 251
+	@echo '04 80 49 92 24 49 92 24 0f b4 ff ff c3 84' | xxd -r -p | puft 2> /dev/null || test $$? -eq 248
+	@echo '04 00 24 e9 ff ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 250
+	@echo '04 00 24 e9 ff 6d' | xxd -r -p | puft 2> /dev/null || test $$? -eq 247
+	@gcov -n puff.c
+
+clean:
+	rm -f puff puft *.o *.gc*
diff --git a/xs/src/png/zlib/contrib/puff/README b/xs/src/png/zlib/contrib/puff/README
new file mode 100644
index 000000000..bbc4cb595
--- /dev/null
+++ b/xs/src/png/zlib/contrib/puff/README
@@ -0,0 +1,63 @@
+Puff -- A Simple Inflate
+3 Mar 2003
+Mark Adler
+madler@alumni.caltech.edu
+
+What this is --
+
+puff.c provides the routine puff() to decompress the deflate data format.  It
+does so more slowly than zlib, but the code is about one-fifth the size of the
+inflate code in zlib, and written to be very easy to read.
+
+Why I wrote this --
+
+puff.c was written to document the deflate format unambiguously, by virtue of
+being working C code.  It is meant to supplement RFC 1951, which formally
+describes the deflate format.  I have received many questions on details of the
+deflate format, and I hope that reading this code will answer those questions.
+puff.c is heavily commented with details of the deflate format, especially
+those little nooks and cranies of the format that might not be obvious from a
+specification.
+
+puff.c may also be useful in applications where code size or memory usage is a
+very limited resource, and speed is not as important.
+
+How to use it --
+
+Well, most likely you should just be reading puff.c and using zlib for actual
+applications, but if you must ...
+
+Include puff.h in your code, which provides this prototype:
+
+int puff(unsigned char *dest,           /* pointer to destination pointer */
+         unsigned long *destlen,        /* amount of output space */
+         unsigned char *source,         /* pointer to source data pointer */
+         unsigned long *sourcelen);     /* amount of input available */
+
+Then you can call puff() to decompress a deflate stream that is in memory in
+its entirety at source, to a sufficiently sized block of memory for the
+decompressed data at dest.  puff() is the only external symbol in puff.c  The
+only C library functions that puff.c needs are setjmp() and longjmp(), which
+are used to simplify error checking in the code to improve readabilty.  puff.c
+does no memory allocation, and uses less than 2K bytes off of the stack.
+
+If destlen is not enough space for the uncompressed data, then inflate will
+return an error without writing more than destlen bytes.  Note that this means
+that in order to decompress the deflate data successfully, you need to know
+the size of the uncompressed data ahead of time.
+
+If needed, puff() can determine the size of the uncompressed data with no
+output space.  This is done by passing dest equal to (unsigned char *)0.  Then
+the initial value of *destlen is ignored and *destlen is set to the length of
+the uncompressed data.  So if the size of the uncompressed data is not known,
+then two passes of puff() can be used--first to determine the size, and second
+to do the actual inflation after allocating the appropriate memory.  Not
+pretty, but it works.  (This is one of the reasons you should be using zlib.)
+
+The deflate format is self-terminating.  If the deflate stream does not end
+in *sourcelen bytes, puff() will return an error without reading at or past
+endsource.
+
+On return, *sourcelen is updated to the amount of input data consumed, and
+*destlen is updated to the size of the uncompressed data.  See the comments
+in puff.c for the possible return codes for puff().
diff --git a/xs/src/png/zlib/contrib/puff/puff.c b/xs/src/png/zlib/contrib/puff/puff.c
new file mode 100644
index 000000000..c6c90d714
--- /dev/null
+++ b/xs/src/png/zlib/contrib/puff/puff.c
@@ -0,0 +1,840 @@
+/*
+ * puff.c
+ * Copyright (C) 2002-2013 Mark Adler
+ * For conditions of distribution and use, see copyright notice in puff.h
+ * version 2.3, 21 Jan 2013
+ *
+ * puff.c is a simple inflate written to be an unambiguous way to specify the
+ * deflate format.  It is not written for speed but rather simplicity.  As a
+ * side benefit, this code might actually be useful when small code is more
+ * important than speed, such as bootstrap applications.  For typical deflate
+ * data, zlib's inflate() is about four times as fast as puff().  zlib's
+ * inflate compiles to around 20K on my machine, whereas puff.c compiles to
+ * around 4K on my machine (a PowerPC using GNU cc).  If the faster decode()
+ * function here is used, then puff() is only twice as slow as zlib's
+ * inflate().
+ *
+ * All dynamically allocated memory comes from the stack.  The stack required
+ * is less than 2K bytes.  This code is compatible with 16-bit int's and
+ * assumes that long's are at least 32 bits.  puff.c uses the short data type,
+ * assumed to be 16 bits, for arrays in order to conserve memory.  The code
+ * works whether integers are stored big endian or little endian.
+ *
+ * In the comments below are "Format notes" that describe the inflate process
+ * and document some of the less obvious aspects of the format.  This source
+ * code is meant to supplement RFC 1951, which formally describes the deflate
+ * format:
+ *
+ *    http://www.zlib.org/rfc-deflate.html
+ */
+
+/*
+ * Change history:
+ *
+ * 1.0  10 Feb 2002     - First version
+ * 1.1  17 Feb 2002     - Clarifications of some comments and notes
+ *                      - Update puff() dest and source pointers on negative
+ *                        errors to facilitate debugging deflators
+ *                      - Remove longest from struct huffman -- not needed
+ *                      - Simplify offs[] index in construct()
+ *                      - Add input size and checking, using longjmp() to
+ *                        maintain easy readability
+ *                      - Use short data type for large arrays
+ *                      - Use pointers instead of long to specify source and
+ *                        destination sizes to avoid arbitrary 4 GB limits
+ * 1.2  17 Mar 2002     - Add faster version of decode(), doubles speed (!),
+ *                        but leave simple version for readabilty
+ *                      - Make sure invalid distances detected if pointers
+ *                        are 16 bits
+ *                      - Fix fixed codes table error
+ *                      - Provide a scanning mode for determining size of
+ *                        uncompressed data
+ * 1.3  20 Mar 2002     - Go back to lengths for puff() parameters [Gailly]
+ *                      - Add a puff.h file for the interface
+ *                      - Add braces in puff() for else do [Gailly]
+ *                      - Use indexes instead of pointers for readability
+ * 1.4  31 Mar 2002     - Simplify construct() code set check
+ *                      - Fix some comments
+ *                      - Add FIXLCODES #define
+ * 1.5   6 Apr 2002     - Minor comment fixes
+ * 1.6   7 Aug 2002     - Minor format changes
+ * 1.7   3 Mar 2003     - Added test code for distribution
+ *                      - Added zlib-like license
+ * 1.8   9 Jan 2004     - Added some comments on no distance codes case
+ * 1.9  21 Feb 2008     - Fix bug on 16-bit integer architectures [Pohland]
+ *                      - Catch missing end-of-block symbol error
+ * 2.0  25 Jul 2008     - Add #define to permit distance too far back
+ *                      - Add option in TEST code for puff to write the data
+ *                      - Add option in TEST code to skip input bytes
+ *                      - Allow TEST code to read from piped stdin
+ * 2.1   4 Apr 2010     - Avoid variable initialization for happier compilers
+ *                      - Avoid unsigned comparisons for even happier compilers
+ * 2.2  25 Apr 2010     - Fix bug in variable initializations [Oberhumer]
+ *                      - Add const where appropriate [Oberhumer]
+ *                      - Split if's and ?'s for coverage testing
+ *                      - Break out test code to separate file
+ *                      - Move NIL to puff.h
+ *                      - Allow incomplete code only if single code length is 1
+ *                      - Add full code coverage test to Makefile
+ * 2.3  21 Jan 2013     - Check for invalid code length codes in dynamic blocks
+ */
+
+#include <setjmp.h>             /* for setjmp(), longjmp(), and jmp_buf */
+#include "puff.h"               /* prototype for puff() */
+
+#define local static            /* for local function definitions */
+
+/*
+ * Maximums for allocations and loops.  It is not useful to change these --
+ * they are fixed by the deflate format.
+ */
+#define MAXBITS 15              /* maximum bits in a code */
+#define MAXLCODES 286           /* maximum number of literal/length codes */
+#define MAXDCODES 30            /* maximum number of distance codes */
+#define MAXCODES (MAXLCODES+MAXDCODES)  /* maximum codes lengths to read */
+#define FIXLCODES 288           /* number of fixed literal/length codes */
+
+/* input and output state */
+struct state {
+    /* output state */
+    unsigned char *out;         /* output buffer */
+    unsigned long outlen;       /* available space at out */
+    unsigned long outcnt;       /* bytes written to out so far */
+
+    /* input state */
+    const unsigned char *in;    /* input buffer */
+    unsigned long inlen;        /* available input at in */
+    unsigned long incnt;        /* bytes read so far */
+    int bitbuf;                 /* bit buffer */
+    int bitcnt;                 /* number of bits in bit buffer */
+
+    /* input limit error return state for bits() and decode() */
+    jmp_buf env;
+};
+
+/*
+ * Return need bits from the input stream.  This always leaves less than
+ * eight bits in the buffer.  bits() works properly for need == 0.
+ *
+ * Format notes:
+ *
+ * - Bits are stored in bytes from the least significant bit to the most
+ *   significant bit.  Therefore bits are dropped from the bottom of the bit
+ *   buffer, using shift right, and new bytes are appended to the top of the
+ *   bit buffer, using shift left.
+ */
+local int bits(struct state *s, int need)
+{
+    long val;           /* bit accumulator (can use up to 20 bits) */
+
+    /* load at least need bits into val */
+    val = s->bitbuf;
+    while (s->bitcnt < need) {
+        if (s->incnt == s->inlen)
+            longjmp(s->env, 1);         /* out of input */
+        val |= (long)(s->in[s->incnt++]) << s->bitcnt;  /* load eight bits */
+        s->bitcnt += 8;
+    }
+
+    /* drop need bits and update buffer, always zero to seven bits left */
+    s->bitbuf = (int)(val >> need);
+    s->bitcnt -= need;
+
+    /* return need bits, zeroing the bits above that */
+    return (int)(val & ((1L << need) - 1));
+}
+
+/*
+ * Process a stored block.
+ *
+ * Format notes:
+ *
+ * - After the two-bit stored block type (00), the stored block length and
+ *   stored bytes are byte-aligned for fast copying.  Therefore any leftover
+ *   bits in the byte that has the last bit of the type, as many as seven, are
+ *   discarded.  The value of the discarded bits are not defined and should not
+ *   be checked against any expectation.
+ *
+ * - The second inverted copy of the stored block length does not have to be
+ *   checked, but it's probably a good idea to do so anyway.
+ *
+ * - A stored block can have zero length.  This is sometimes used to byte-align
+ *   subsets of the compressed data for random access or partial recovery.
+ */
+local int stored(struct state *s)
+{
+    unsigned len;       /* length of stored block */
+
+    /* discard leftover bits from current byte (assumes s->bitcnt < 8) */
+    s->bitbuf = 0;
+    s->bitcnt = 0;
+
+    /* get length and check against its one's complement */
+    if (s->incnt + 4 > s->inlen)
+        return 2;                               /* not enough input */
+    len = s->in[s->incnt++];
+    len |= s->in[s->incnt++] << 8;
+    if (s->in[s->incnt++] != (~len & 0xff) ||
+        s->in[s->incnt++] != ((~len >> 8) & 0xff))
+        return -2;                              /* didn't match complement! */
+
+    /* copy len bytes from in to out */
+    if (s->incnt + len > s->inlen)
+        return 2;                               /* not enough input */
+    if (s->out != NIL) {
+        if (s->outcnt + len > s->outlen)
+            return 1;                           /* not enough output space */
+        while (len--)
+            s->out[s->outcnt++] = s->in[s->incnt++];
+    }
+    else {                                      /* just scanning */
+        s->outcnt += len;
+        s->incnt += len;
+    }
+
+    /* done with a valid stored block */
+    return 0;
+}
+
+/*
+ * Huffman code decoding tables.  count[1..MAXBITS] is the number of symbols of
+ * each length, which for a canonical code are stepped through in order.
+ * symbol[] are the symbol values in canonical order, where the number of
+ * entries is the sum of the counts in count[].  The decoding process can be
+ * seen in the function decode() below.
+ */
+struct huffman {
+    short *count;       /* number of symbols of each length */
+    short *symbol;      /* canonically ordered symbols */
+};
+
+/*
+ * Decode a code from the stream s using huffman table h.  Return the symbol or
+ * a negative value if there is an error.  If all of the lengths are zero, i.e.
+ * an empty code, or if the code is incomplete and an invalid code is received,
+ * then -10 is returned after reading MAXBITS bits.
+ *
+ * Format notes:
+ *
+ * - The codes as stored in the compressed data are bit-reversed relative to
+ *   a simple integer ordering of codes of the same lengths.  Hence below the
+ *   bits are pulled from the compressed data one at a time and used to
+ *   build the code value reversed from what is in the stream in order to
+ *   permit simple integer comparisons for decoding.  A table-based decoding
+ *   scheme (as used in zlib) does not need to do this reversal.
+ *
+ * - The first code for the shortest length is all zeros.  Subsequent codes of
+ *   the same length are simply integer increments of the previous code.  When
+ *   moving up a length, a zero bit is appended to the code.  For a complete
+ *   code, the last code of the longest length will be all ones.
+ *
+ * - Incomplete codes are handled by this decoder, since they are permitted
+ *   in the deflate format.  See the format notes for fixed() and dynamic().
+ */
+#ifdef SLOW
+local int decode(struct state *s, const struct huffman *h)
+{
+    int len;            /* current number of bits in code */
+    int code;           /* len bits being decoded */
+    int first;          /* first code of length len */
+    int count;          /* number of codes of length len */
+    int index;          /* index of first code of length len in symbol table */
+
+    code = first = index = 0;
+    for (len = 1; len <= MAXBITS; len++) {
+        code |= bits(s, 1);             /* get next bit */
+        count = h->count[len];
+        if (code - count < first)       /* if length len, return symbol */
+            return h->symbol[index + (code - first)];
+        index += count;                 /* else update for next length */
+        first += count;
+        first <<= 1;
+        code <<= 1;
+    }
+    return -10;                         /* ran out of codes */
+}
+
+/*
+ * A faster version of decode() for real applications of this code.   It's not
+ * as readable, but it makes puff() twice as fast.  And it only makes the code
+ * a few percent larger.
+ */
+#else /* !SLOW */
+local int decode(struct state *s, const struct huffman *h)
+{
+    int len;            /* current number of bits in code */
+    int code;           /* len bits being decoded */
+    int first;          /* first code of length len */
+    int count;          /* number of codes of length len */
+    int index;          /* index of first code of length len in symbol table */
+    int bitbuf;         /* bits from stream */
+    int left;           /* bits left in next or left to process */
+    short *next;        /* next number of codes */
+
+    bitbuf = s->bitbuf;
+    left = s->bitcnt;
+    code = first = index = 0;
+    len = 1;
+    next = h->count + 1;
+    while (1) {
+        while (left--) {
+            code |= bitbuf & 1;
+            bitbuf >>= 1;
+            count = *next++;
+            if (code - count < first) { /* if length len, return symbol */
+                s->bitbuf = bitbuf;
+                s->bitcnt = (s->bitcnt - len) & 7;
+                return h->symbol[index + (code - first)];
+            }
+            index += count;             /* else update for next length */
+            first += count;
+            first <<= 1;
+            code <<= 1;
+            len++;
+        }
+        left = (MAXBITS+1) - len;
+        if (left == 0)
+            break;
+        if (s->incnt == s->inlen)
+            longjmp(s->env, 1);         /* out of input */
+        bitbuf = s->in[s->incnt++];
+        if (left > 8)
+            left = 8;
+    }
+    return -10;                         /* ran out of codes */
+}
+#endif /* SLOW */
+
+/*
+ * Given the list of code lengths length[0..n-1] representing a canonical
+ * Huffman code for n symbols, construct the tables required to decode those
+ * codes.  Those tables are the number of codes of each length, and the symbols
+ * sorted by length, retaining their original order within each length.  The
+ * return value is zero for a complete code set, negative for an over-
+ * subscribed code set, and positive for an incomplete code set.  The tables
+ * can be used if the return value is zero or positive, but they cannot be used
+ * if the return value is negative.  If the return value is zero, it is not
+ * possible for decode() using that table to return an error--any stream of
+ * enough bits will resolve to a symbol.  If the return value is positive, then
+ * it is possible for decode() using that table to return an error for received
+ * codes past the end of the incomplete lengths.
+ *
+ * Not used by decode(), but used for error checking, h->count[0] is the number
+ * of the n symbols not in the code.  So n - h->count[0] is the number of
+ * codes.  This is useful for checking for incomplete codes that have more than
+ * one symbol, which is an error in a dynamic block.
+ *
+ * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS
+ * This is assured by the construction of the length arrays in dynamic() and
+ * fixed() and is not verified by construct().
+ *
+ * Format notes:
+ *
+ * - Permitted and expected examples of incomplete codes are one of the fixed
+ *   codes and any code with a single symbol which in deflate is coded as one
+ *   bit instead of zero bits.  See the format notes for fixed() and dynamic().
+ *
+ * - Within a given code length, the symbols are kept in ascending order for
+ *   the code bits definition.
+ */
+local int construct(struct huffman *h, const short *length, int n)
+{
+    int symbol;         /* current symbol when stepping through length[] */
+    int len;            /* current length when stepping through h->count[] */
+    int left;           /* number of possible codes left of current length */
+    short offs[MAXBITS+1];      /* offsets in symbol table for each length */
+
+    /* count number of codes of each length */
+    for (len = 0; len <= MAXBITS; len++)
+        h->count[len] = 0;
+    for (symbol = 0; symbol < n; symbol++)
+        (h->count[length[symbol]])++;   /* assumes lengths are within bounds */
+    if (h->count[0] == n)               /* no codes! */
+        return 0;                       /* complete, but decode() will fail */
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;                           /* one possible code of zero length */
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;                     /* one more bit, double codes left */
+        left -= h->count[len];          /* deduct count from possible codes */
+        if (left < 0)
+            return left;                /* over-subscribed--return negative */
+    }                                   /* left > 0 means incomplete */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + h->count[len];
+
+    /*
+     * put symbols in table sorted by length, by symbol order within each
+     * length
+     */
+    for (symbol = 0; symbol < n; symbol++)
+        if (length[symbol] != 0)
+            h->symbol[offs[length[symbol]]++] = symbol;
+
+    /* return zero for complete set, positive for incomplete set */
+    return left;
+}
+
+/*
+ * Decode literal/length and distance codes until an end-of-block code.
+ *
+ * Format notes:
+ *
+ * - Compressed data that is after the block type if fixed or after the code
+ *   description if dynamic is a combination of literals and length/distance
+ *   pairs terminated by and end-of-block code.  Literals are simply Huffman
+ *   coded bytes.  A length/distance pair is a coded length followed by a
+ *   coded distance to represent a string that occurs earlier in the
+ *   uncompressed data that occurs again at the current location.
+ *
+ * - Literals, lengths, and the end-of-block code are combined into a single
+ *   code of up to 286 symbols.  They are 256 literals (0..255), 29 length
+ *   symbols (257..285), and the end-of-block symbol (256).
+ *
+ * - There are 256 possible lengths (3..258), and so 29 symbols are not enough
+ *   to represent all of those.  Lengths 3..10 and 258 are in fact represented
+ *   by just a length symbol.  Lengths 11..257 are represented as a symbol and
+ *   some number of extra bits that are added as an integer to the base length
+ *   of the length symbol.  The number of extra bits is determined by the base
+ *   length symbol.  These are in the static arrays below, lens[] for the base
+ *   lengths and lext[] for the corresponding number of extra bits.
+ *
+ * - The reason that 258 gets its own symbol is that the longest length is used
+ *   often in highly redundant files.  Note that 258 can also be coded as the
+ *   base value 227 plus the maximum extra value of 31.  While a good deflate
+ *   should never do this, it is not an error, and should be decoded properly.
+ *
+ * - If a length is decoded, including its extra bits if any, then it is
+ *   followed a distance code.  There are up to 30 distance symbols.  Again
+ *   there are many more possible distances (1..32768), so extra bits are added
+ *   to a base value represented by the symbol.  The distances 1..4 get their
+ *   own symbol, but the rest require extra bits.  The base distances and
+ *   corresponding number of extra bits are below in the static arrays dist[]
+ *   and dext[].
+ *
+ * - Literal bytes are simply written to the output.  A length/distance pair is
+ *   an instruction to copy previously uncompressed bytes to the output.  The
+ *   copy is from distance bytes back in the output stream, copying for length
+ *   bytes.
+ *
+ * - Distances pointing before the beginning of the output data are not
+ *   permitted.
+ *
+ * - Overlapped copies, where the length is greater than the distance, are
+ *   allowed and common.  For example, a distance of one and a length of 258
+ *   simply copies the last byte 258 times.  A distance of four and a length of
+ *   twelve copies the last four bytes three times.  A simple forward copy
+ *   ignoring whether the length is greater than the distance or not implements
+ *   this correctly.  You should not use memcpy() since its behavior is not
+ *   defined for overlapped arrays.  You should not use memmove() or bcopy()
+ *   since though their behavior -is- defined for overlapping arrays, it is
+ *   defined to do the wrong thing in this case.
+ */
+local int codes(struct state *s,
+                const struct huffman *lencode,
+                const struct huffman *distcode)
+{
+    int symbol;         /* decoded symbol */
+    int len;            /* length for copy */
+    unsigned dist;      /* distance for copy */
+    static const short lens[29] = { /* Size base for length codes 257..285 */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258};
+    static const short lext[29] = { /* Extra bits for length codes 257..285 */
+        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0};
+    static const short dists[30] = { /* Offset base for distance codes 0..29 */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577};
+    static const short dext[30] = { /* Extra bits for distance codes 0..29 */
+        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+        12, 12, 13, 13};
+
+    /* decode literals and length/distance pairs */
+    do {
+        symbol = decode(s, lencode);
+        if (symbol < 0)
+            return symbol;              /* invalid symbol */
+        if (symbol < 256) {             /* literal: symbol is the byte */
+            /* write out the literal */
+            if (s->out != NIL) {
+                if (s->outcnt == s->outlen)
+                    return 1;
+                s->out[s->outcnt] = symbol;
+            }
+            s->outcnt++;
+        }
+        else if (symbol > 256) {        /* length */
+            /* get and compute length */
+            symbol -= 257;
+            if (symbol >= 29)
+                return -10;             /* invalid fixed code */
+            len = lens[symbol] + bits(s, lext[symbol]);
+
+            /* get and check distance */
+            symbol = decode(s, distcode);
+            if (symbol < 0)
+                return symbol;          /* invalid symbol */
+            dist = dists[symbol] + bits(s, dext[symbol]);
+#ifndef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+            if (dist > s->outcnt)
+                return -11;     /* distance too far back */
+#endif
+
+            /* copy length bytes from distance bytes back */
+            if (s->out != NIL) {
+                if (s->outcnt + len > s->outlen)
+                    return 1;
+                while (len--) {
+                    s->out[s->outcnt] =
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                        dist > s->outcnt ?
+                            0 :
+#endif
+                            s->out[s->outcnt - dist];
+                    s->outcnt++;
+                }
+            }
+            else
+                s->outcnt += len;
+        }
+    } while (symbol != 256);            /* end of block symbol */
+
+    /* done with a valid fixed or dynamic block */
+    return 0;
+}
+
+/*
+ * Process a fixed codes block.
+ *
+ * Format notes:
+ *
+ * - This block type can be useful for compressing small amounts of data for
+ *   which the size of the code descriptions in a dynamic block exceeds the
+ *   benefit of custom codes for that block.  For fixed codes, no bits are
+ *   spent on code descriptions.  Instead the code lengths for literal/length
+ *   codes and distance codes are fixed.  The specific lengths for each symbol
+ *   can be seen in the "for" loops below.
+ *
+ * - The literal/length code is complete, but has two symbols that are invalid
+ *   and should result in an error if received.  This cannot be implemented
+ *   simply as an incomplete code since those two symbols are in the "middle"
+ *   of the code.  They are eight bits long and the longest literal/length\
+ *   code is nine bits.  Therefore the code must be constructed with those
+ *   symbols, and the invalid symbols must be detected after decoding.
+ *
+ * - The fixed distance codes also have two invalid symbols that should result
+ *   in an error if received.  Since all of the distance codes are the same
+ *   length, this can be implemented as an incomplete code.  Then the invalid
+ *   codes are detected while decoding.
+ */
+local int fixed(struct state *s)
+{
+    static int virgin = 1;
+    static short lencnt[MAXBITS+1], lensym[FIXLCODES];
+    static short distcnt[MAXBITS+1], distsym[MAXDCODES];
+    static struct huffman lencode, distcode;
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        int symbol;
+        short lengths[FIXLCODES];
+
+        /* construct lencode and distcode */
+        lencode.count = lencnt;
+        lencode.symbol = lensym;
+        distcode.count = distcnt;
+        distcode.symbol = distsym;
+
+        /* literal/length table */
+        for (symbol = 0; symbol < 144; symbol++)
+            lengths[symbol] = 8;
+        for (; symbol < 256; symbol++)
+            lengths[symbol] = 9;
+        for (; symbol < 280; symbol++)
+            lengths[symbol] = 7;
+        for (; symbol < FIXLCODES; symbol++)
+            lengths[symbol] = 8;
+        construct(&lencode, lengths, FIXLCODES);
+
+        /* distance table */
+        for (symbol = 0; symbol < MAXDCODES; symbol++)
+            lengths[symbol] = 5;
+        construct(&distcode, lengths, MAXDCODES);
+
+        /* do this just once */
+        virgin = 0;
+    }
+
+    /* decode data until end-of-block code */
+    return codes(s, &lencode, &distcode);
+}
+
+/*
+ * Process a dynamic codes block.
+ *
+ * Format notes:
+ *
+ * - A dynamic block starts with a description of the literal/length and
+ *   distance codes for that block.  New dynamic blocks allow the compressor to
+ *   rapidly adapt to changing data with new codes optimized for that data.
+ *
+ * - The codes used by the deflate format are "canonical", which means that
+ *   the actual bits of the codes are generated in an unambiguous way simply
+ *   from the number of bits in each code.  Therefore the code descriptions
+ *   are simply a list of code lengths for each symbol.
+ *
+ * - The code lengths are stored in order for the symbols, so lengths are
+ *   provided for each of the literal/length symbols, and for each of the
+ *   distance symbols.
+ *
+ * - If a symbol is not used in the block, this is represented by a zero as
+ *   as the code length.  This does not mean a zero-length code, but rather
+ *   that no code should be created for this symbol.  There is no way in the
+ *   deflate format to represent a zero-length code.
+ *
+ * - The maximum number of bits in a code is 15, so the possible lengths for
+ *   any code are 1..15.
+ *
+ * - The fact that a length of zero is not permitted for a code has an
+ *   interesting consequence.  Normally if only one symbol is used for a given
+ *   code, then in fact that code could be represented with zero bits.  However
+ *   in deflate, that code has to be at least one bit.  So for example, if
+ *   only a single distance base symbol appears in a block, then it will be
+ *   represented by a single code of length one, in particular one 0 bit.  This
+ *   is an incomplete code, since if a 1 bit is received, it has no meaning,
+ *   and should result in an error.  So incomplete distance codes of one symbol
+ *   should be permitted, and the receipt of invalid codes should be handled.
+ *
+ * - It is also possible to have a single literal/length code, but that code
+ *   must be the end-of-block code, since every dynamic block has one.  This
+ *   is not the most efficient way to create an empty block (an empty fixed
+ *   block is fewer bits), but it is allowed by the format.  So incomplete
+ *   literal/length codes of one symbol should also be permitted.
+ *
+ * - If there are only literal codes and no lengths, then there are no distance
+ *   codes.  This is represented by one distance code with zero bits.
+ *
+ * - The list of up to 286 length/literal lengths and up to 30 distance lengths
+ *   are themselves compressed using Huffman codes and run-length encoding.  In
+ *   the list of code lengths, a 0 symbol means no code, a 1..15 symbol means
+ *   that length, and the symbols 16, 17, and 18 are run-length instructions.
+ *   Each of 16, 17, and 18 are follwed by extra bits to define the length of
+ *   the run.  16 copies the last length 3 to 6 times.  17 represents 3 to 10
+ *   zero lengths, and 18 represents 11 to 138 zero lengths.  Unused symbols
+ *   are common, hence the special coding for zero lengths.
+ *
+ * - The symbols for 0..18 are Huffman coded, and so that code must be
+ *   described first.  This is simply a sequence of up to 19 three-bit values
+ *   representing no code (0) or the code length for that symbol (1..7).
+ *
+ * - A dynamic block starts with three fixed-size counts from which is computed
+ *   the number of literal/length code lengths, the number of distance code
+ *   lengths, and the number of code length code lengths (ok, you come up with
+ *   a better name!) in the code descriptions.  For the literal/length and
+ *   distance codes, lengths after those provided are considered zero, i.e. no
+ *   code.  The code length code lengths are received in a permuted order (see
+ *   the order[] array below) to make a short code length code length list more
+ *   likely.  As it turns out, very short and very long codes are less likely
+ *   to be seen in a dynamic code description, hence what may appear initially
+ *   to be a peculiar ordering.
+ *
+ * - Given the number of literal/length code lengths (nlen) and distance code
+ *   lengths (ndist), then they are treated as one long list of nlen + ndist
+ *   code lengths.  Therefore run-length coding can and often does cross the
+ *   boundary between the two sets of lengths.
+ *
+ * - So to summarize, the code description at the start of a dynamic block is
+ *   three counts for the number of code lengths for the literal/length codes,
+ *   the distance codes, and the code length codes.  This is followed by the
+ *   code length code lengths, three bits each.  This is used to construct the
+ *   code length code which is used to read the remainder of the lengths.  Then
+ *   the literal/length code lengths and distance lengths are read as a single
+ *   set of lengths using the code length codes.  Codes are constructed from
+ *   the resulting two sets of lengths, and then finally you can start
+ *   decoding actual compressed data in the block.
+ *
+ * - For reference, a "typical" size for the code description in a dynamic
+ *   block is around 80 bytes.
+ */
+local int dynamic(struct state *s)
+{
+    int nlen, ndist, ncode;             /* number of lengths in descriptor */
+    int index;                          /* index of lengths[] */
+    int err;                            /* construct() return value */
+    short lengths[MAXCODES];            /* descriptor code lengths */
+    short lencnt[MAXBITS+1], lensym[MAXLCODES];         /* lencode memory */
+    short distcnt[MAXBITS+1], distsym[MAXDCODES];       /* distcode memory */
+    struct huffman lencode, distcode;   /* length and distance codes */
+    static const short order[19] =      /* permutation of code length codes */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    /* construct lencode and distcode */
+    lencode.count = lencnt;
+    lencode.symbol = lensym;
+    distcode.count = distcnt;
+    distcode.symbol = distsym;
+
+    /* get number of lengths in each table, check lengths */
+    nlen = bits(s, 5) + 257;
+    ndist = bits(s, 5) + 1;
+    ncode = bits(s, 4) + 4;
+    if (nlen > MAXLCODES || ndist > MAXDCODES)
+        return -3;                      /* bad counts */
+
+    /* read code length code lengths (really), missing lengths are zero */
+    for (index = 0; index < ncode; index++)
+        lengths[order[index]] = bits(s, 3);
+    for (; index < 19; index++)
+        lengths[order[index]] = 0;
+
+    /* build huffman table for code lengths codes (use lencode temporarily) */
+    err = construct(&lencode, lengths, 19);
+    if (err != 0)               /* require complete code set here */
+        return -4;
+
+    /* read length/literal and distance code length tables */
+    index = 0;
+    while (index < nlen + ndist) {
+        int symbol;             /* decoded value */
+        int len;                /* last length to repeat */
+
+        symbol = decode(s, &lencode);
+        if (symbol < 0)
+            return symbol;          /* invalid symbol */
+        if (symbol < 16)                /* length in 0..15 */
+            lengths[index++] = symbol;
+        else {                          /* repeat instruction */
+            len = 0;                    /* assume repeating zeros */
+            if (symbol == 16) {         /* repeat last length 3..6 times */
+                if (index == 0)
+                    return -5;          /* no last length! */
+                len = lengths[index - 1];       /* last length */
+                symbol = 3 + bits(s, 2);
+            }
+            else if (symbol == 17)      /* repeat zero 3..10 times */
+                symbol = 3 + bits(s, 3);
+            else                        /* == 18, repeat zero 11..138 times */
+                symbol = 11 + bits(s, 7);
+            if (index + symbol > nlen + ndist)
+                return -6;              /* too many lengths! */
+            while (symbol--)            /* repeat last or zero symbol times */
+                lengths[index++] = len;
+        }
+    }
+
+    /* check for end-of-block code -- there better be one! */
+    if (lengths[256] == 0)
+        return -9;
+
+    /* build huffman table for literal/length codes */
+    err = construct(&lencode, lengths, nlen);
+    if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1]))
+        return -7;      /* incomplete code ok only for single length 1 code */
+
+    /* build huffman table for distance codes */
+    err = construct(&distcode, lengths + nlen, ndist);
+    if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1]))
+        return -8;      /* incomplete code ok only for single length 1 code */
+
+    /* decode data until end-of-block code */
+    return codes(s, &lencode, &distcode);
+}
+
+/*
+ * Inflate source to dest.  On return, destlen and sourcelen are updated to the
+ * size of the uncompressed data and the size of the deflate data respectively.
+ * On success, the return value of puff() is zero.  If there is an error in the
+ * source data, i.e. it is not in the deflate format, then a negative value is
+ * returned.  If there is not enough input available or there is not enough
+ * output space, then a positive error is returned.  In that case, destlen and
+ * sourcelen are not updated to facilitate retrying from the beginning with the
+ * provision of more input data or more output space.  In the case of invalid
+ * inflate data (a negative error), the dest and source pointers are updated to
+ * facilitate the debugging of deflators.
+ *
+ * puff() also has a mode to determine the size of the uncompressed output with
+ * no output written.  For this dest must be (unsigned char *)0.  In this case,
+ * the input value of *destlen is ignored, and on return *destlen is set to the
+ * size of the uncompressed output.
+ *
+ * The return codes are:
+ *
+ *   2:  available inflate data did not terminate
+ *   1:  output space exhausted before completing inflate
+ *   0:  successful inflate
+ *  -1:  invalid block type (type == 3)
+ *  -2:  stored block length did not match one's complement
+ *  -3:  dynamic block code description: too many length or distance codes
+ *  -4:  dynamic block code description: code lengths codes incomplete
+ *  -5:  dynamic block code description: repeat lengths with no first length
+ *  -6:  dynamic block code description: repeat more than specified lengths
+ *  -7:  dynamic block code description: invalid literal/length code lengths
+ *  -8:  dynamic block code description: invalid distance code lengths
+ *  -9:  dynamic block code description: missing end-of-block code
+ * -10:  invalid literal/length or distance code in fixed or dynamic block
+ * -11:  distance is too far back in fixed or dynamic block
+ *
+ * Format notes:
+ *
+ * - Three bits are read for each block to determine the kind of block and
+ *   whether or not it is the last block.  Then the block is decoded and the
+ *   process repeated if it was not the last block.
+ *
+ * - The leftover bits in the last byte of the deflate data after the last
+ *   block (if it was a fixed or dynamic block) are undefined and have no
+ *   expected values to check.
+ */
+int puff(unsigned char *dest,           /* pointer to destination pointer */
+         unsigned long *destlen,        /* amount of output space */
+         const unsigned char *source,   /* pointer to source data pointer */
+         unsigned long *sourcelen)      /* amount of input available */
+{
+    struct state s;             /* input/output state */
+    int last, type;             /* block information */
+    int err;                    /* return value */
+
+    /* initialize output state */
+    s.out = dest;
+    s.outlen = *destlen;                /* ignored if dest is NIL */
+    s.outcnt = 0;
+
+    /* initialize input state */
+    s.in = source;
+    s.inlen = *sourcelen;
+    s.incnt = 0;
+    s.bitbuf = 0;
+    s.bitcnt = 0;
+
+    /* return if bits() or decode() tries to read past available input */
+    if (setjmp(s.env) != 0)             /* if came back here via longjmp() */
+        err = 2;                        /* then skip do-loop, return error */
+    else {
+        /* process blocks until last block or error */
+        do {
+            last = bits(&s, 1);         /* one if last block */
+            type = bits(&s, 2);         /* block type 0..3 */
+            err = type == 0 ?
+                    stored(&s) :
+                    (type == 1 ?
+                        fixed(&s) :
+                        (type == 2 ?
+                            dynamic(&s) :
+                            -1));       /* type == 3, invalid */
+            if (err != 0)
+                break;                  /* return with error */
+        } while (!last);
+    }
+
+    /* update the lengths and return */
+    if (err <= 0) {
+        *destlen = s.outcnt;
+        *sourcelen = s.incnt;
+    }
+    return err;
+}
diff --git a/xs/src/png/zlib/contrib/puff/puff.h b/xs/src/png/zlib/contrib/puff/puff.h
new file mode 100644
index 000000000..e23a24543
--- /dev/null
+++ b/xs/src/png/zlib/contrib/puff/puff.h
@@ -0,0 +1,35 @@
+/* puff.h
+  Copyright (C) 2002-2013 Mark Adler, all rights reserved
+  version 2.3, 21 Jan 2013
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+
+/*
+ * See puff.c for purpose and usage.
+ */
+#ifndef NIL
+#  define NIL ((unsigned char *)0)      /* for no output option */
+#endif
+
+int puff(unsigned char *dest,           /* pointer to destination pointer */
+         unsigned long *destlen,        /* amount of output space */
+         const unsigned char *source,   /* pointer to source data pointer */
+         unsigned long *sourcelen);     /* amount of input available */
diff --git a/xs/src/png/zlib/contrib/puff/pufftest.c b/xs/src/png/zlib/contrib/puff/pufftest.c
new file mode 100644
index 000000000..776481488
--- /dev/null
+++ b/xs/src/png/zlib/contrib/puff/pufftest.c
@@ -0,0 +1,165 @@
+/*
+ * pufftest.c
+ * Copyright (C) 2002-2013 Mark Adler
+ * For conditions of distribution and use, see copyright notice in puff.h
+ * version 2.3, 21 Jan 2013
+ */
+
+/* Example of how to use puff().
+
+   Usage: puff [-w] [-f] [-nnn] file
+          ... | puff [-w] [-f] [-nnn]
+
+   where file is the input file with deflate data, nnn is the number of bytes
+   of input to skip before inflating (e.g. to skip a zlib or gzip header), and
+   -w is used to write the decompressed data to stdout.  -f is for coverage
+   testing, and causes pufftest to fail with not enough output space (-f does
+   a write like -w, so -w is not required). */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "puff.h"
+
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
+#  include <fcntl.h>
+#  include <io.h>
+#  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+#  define SET_BINARY_MODE(file)
+#endif
+
+#define local static
+
+/* Return size times approximately the cube root of 2, keeping the result as 1,
+   3, or 5 times a power of 2 -- the result is always > size, until the result
+   is the maximum value of an unsigned long, where it remains.  This is useful
+   to keep reallocations less than ~33% over the actual data. */
+local size_t bythirds(size_t size)
+{
+    int n;
+    size_t m;
+
+    m = size;
+    for (n = 0; m; n++)
+        m >>= 1;
+    if (n < 3)
+        return size + 1;
+    n -= 3;
+    m = size >> n;
+    m += m == 6 ? 2 : 1;
+    m <<= n;
+    return m > size ? m : (size_t)(-1);
+}
+
+/* Read the input file *name, or stdin if name is NULL, into allocated memory.
+   Reallocate to larger buffers until the entire file is read in.  Return a
+   pointer to the allocated data, or NULL if there was a memory allocation
+   failure.  *len is the number of bytes of data read from the input file (even
+   if load() returns NULL).  If the input file was empty or could not be opened
+   or read, *len is zero. */
+local void *load(const char *name, size_t *len)
+{
+    size_t size;
+    void *buf, *swap;
+    FILE *in;
+
+    *len = 0;
+    buf = malloc(size = 4096);
+    if (buf == NULL)
+        return NULL;
+    in = name == NULL ? stdin : fopen(name, "rb");
+    if (in != NULL) {
+        for (;;) {
+            *len += fread((char *)buf + *len, 1, size - *len, in);
+            if (*len < size) break;
+            size = bythirds(size);
+            if (size == *len || (swap = realloc(buf, size)) == NULL) {
+                free(buf);
+                buf = NULL;
+                break;
+            }
+            buf = swap;
+        }
+        fclose(in);
+    }
+    return buf;
+}
+
+int main(int argc, char **argv)
+{
+    int ret, put = 0, fail = 0;
+    unsigned skip = 0;
+    char *arg, *name = NULL;
+    unsigned char *source = NULL, *dest;
+    size_t len = 0;
+    unsigned long sourcelen, destlen;
+
+    /* process arguments */
+    while (arg = *++argv, --argc)
+        if (arg[0] == '-') {
+            if (arg[1] == 'w' && arg[2] == 0)
+                put = 1;
+            else if (arg[1] == 'f' && arg[2] == 0)
+                fail = 1, put = 1;
+            else if (arg[1] >= '0' && arg[1] <= '9')
+                skip = (unsigned)atoi(arg + 1);
+            else {
+                fprintf(stderr, "invalid option %s\n", arg);
+                return 3;
+            }
+        }
+        else if (name != NULL) {
+            fprintf(stderr, "only one file name allowed\n");
+            return 3;
+        }
+        else
+            name = arg;
+    source = load(name, &len);
+    if (source == NULL) {
+        fprintf(stderr, "memory allocation failure\n");
+        return 4;
+    }
+    if (len == 0) {
+        fprintf(stderr, "could not read %s, or it was empty\n",
+                name == NULL ? "<stdin>" : name);
+        free(source);
+        return 3;
+    }
+    if (skip >= len) {
+        fprintf(stderr, "skip request of %d leaves no input\n", skip);
+        free(source);
+        return 3;
+    }
+
+    /* test inflate data with offset skip */
+    len -= skip;
+    sourcelen = (unsigned long)len;
+    ret = puff(NIL, &destlen, source + skip, &sourcelen);
+    if (ret)
+        fprintf(stderr, "puff() failed with return code %d\n", ret);
+    else {
+        fprintf(stderr, "puff() succeeded uncompressing %lu bytes\n", destlen);
+        if (sourcelen < len) fprintf(stderr, "%lu compressed bytes unused\n",
+                                     len - sourcelen);
+    }
+
+    /* if requested, inflate again and write decompressd data to stdout */
+    if (put && ret == 0) {
+        if (fail)
+            destlen >>= 1;
+        dest = malloc(destlen);
+        if (dest == NULL) {
+            fprintf(stderr, "memory allocation failure\n");
+            free(source);
+            return 4;
+        }
+        puff(dest, &destlen, source + skip, &sourcelen);
+        SET_BINARY_MODE(stdout);
+        fwrite(dest, 1, destlen, stdout);
+        free(dest);
+    }
+
+    /* clean up */
+    free(source);
+    return ret;
+}
diff --git a/xs/src/png/zlib/contrib/puff/zeros.raw b/xs/src/png/zlib/contrib/puff/zeros.raw
new file mode 100644
index 000000000..0a90e76b3
--- /dev/null
+++ b/xs/src/png/zlib/contrib/puff/zeros.raw
diff --git a/xs/src/png/zlib/contrib/testzlib/testzlib.c b/xs/src/png/zlib/contrib/testzlib/testzlib.c
new file mode 100644
index 000000000..8626c92ad
--- /dev/null
+++ b/xs/src/png/zlib/contrib/testzlib/testzlib.c
@@ -0,0 +1,275 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <windows.h>
+
+#include "zlib.h"
+
+
+void MyDoMinus64(LARGE_INTEGER *R,LARGE_INTEGER A,LARGE_INTEGER B)
+{
+    R->HighPart = A.HighPart - B.HighPart;
+    if (A.LowPart >= B.LowPart)
+        R->LowPart = A.LowPart - B.LowPart;
+    else
+    {
+        R->LowPart = A.LowPart - B.LowPart;
+        R->HighPart --;
+    }
+}
+
+#ifdef _M_X64
+// see http://msdn2.microsoft.com/library/twchhe95(en-us,vs.80).aspx for __rdtsc
+unsigned __int64 __rdtsc(void);
+void BeginCountRdtsc(LARGE_INTEGER * pbeginTime64)
+{
+ //   printf("rdtsc = %I64x\n",__rdtsc());
+   pbeginTime64->QuadPart=__rdtsc();
+}
+
+LARGE_INTEGER GetResRdtsc(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER LIres;
+    unsigned _int64 res=__rdtsc()-((unsigned _int64)(beginTime64.QuadPart));
+    LIres.QuadPart=res;
+   // printf("rdtsc = %I64x\n",__rdtsc());
+    return LIres;
+}
+#else
+#ifdef _M_IX86
+void myGetRDTSC32(LARGE_INTEGER * pbeginTime64)
+{
+    DWORD dwEdx,dwEax;
+    _asm
+    {
+        rdtsc
+        mov dwEax,eax
+        mov dwEdx,edx
+    }
+    pbeginTime64->LowPart=dwEax;
+    pbeginTime64->HighPart=dwEdx;
+}
+
+void BeginCountRdtsc(LARGE_INTEGER * pbeginTime64)
+{
+    myGetRDTSC32(pbeginTime64);
+}
+
+LARGE_INTEGER GetResRdtsc(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER LIres,endTime64;
+    myGetRDTSC32(&endTime64);
+
+    LIres.LowPart=LIres.HighPart=0;
+    MyDoMinus64(&LIres,endTime64,beginTime64);
+    return LIres;
+}
+#else
+void myGetRDTSC32(LARGE_INTEGER * pbeginTime64)
+{
+}
+
+void BeginCountRdtsc(LARGE_INTEGER * pbeginTime64)
+{
+}
+
+LARGE_INTEGER GetResRdtsc(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER lr;
+    lr.QuadPart=0;
+    return lr;
+}
+#endif
+#endif
+
+void BeginCountPerfCounter(LARGE_INTEGER * pbeginTime64,BOOL fComputeTimeQueryPerf)
+{
+    if ((!fComputeTimeQueryPerf) || (!QueryPerformanceCounter(pbeginTime64)))
+    {
+        pbeginTime64->LowPart = GetTickCount();
+        pbeginTime64->HighPart = 0;
+    }
+}
+
+DWORD GetMsecSincePerfCounter(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER endTime64,ticksPerSecond,ticks;
+    DWORDLONG ticksShifted,tickSecShifted;
+    DWORD dwLog=16+0;
+    DWORD dwRet;
+    if ((!fComputeTimeQueryPerf) || (!QueryPerformanceCounter(&endTime64)))
+        dwRet = (GetTickCount() - beginTime64.LowPart)*1;
+    else
+    {
+        MyDoMinus64(&ticks,endTime64,beginTime64);
+        QueryPerformanceFrequency(&ticksPerSecond);
+
+
+        {
+            ticksShifted = Int64ShrlMod32(*(DWORDLONG*)&ticks,dwLog);
+            tickSecShifted = Int64ShrlMod32(*(DWORDLONG*)&ticksPerSecond,dwLog);
+
+        }
+
+        dwRet = (DWORD)((((DWORD)ticksShifted)*1000)/(DWORD)(tickSecShifted));
+        dwRet *=1;
+    }
+    return dwRet;
+}
+
+int ReadFileMemory(const char* filename,long* plFileSize,unsigned char** pFilePtr)
+{
+    FILE* stream;
+    unsigned char* ptr;
+    int retVal=1;
+    stream=fopen(filename, "rb");
+    if (stream==NULL)
+        return 0;
+
+    fseek(stream,0,SEEK_END);
+
+    *plFileSize=ftell(stream);
+    fseek(stream,0,SEEK_SET);
+    ptr=malloc((*plFileSize)+1);
+    if (ptr==NULL)
+        retVal=0;
+    else
+    {
+        if (fread(ptr, 1, *plFileSize,stream) != (*plFileSize))
+            retVal=0;
+    }
+    fclose(stream);
+    *pFilePtr=ptr;
+    return retVal;
+}
+
+int main(int argc, char *argv[])
+{
+    int BlockSizeCompress=0x8000;
+    int BlockSizeUncompress=0x8000;
+    int cprLevel=Z_DEFAULT_COMPRESSION ;
+    long lFileSize;
+    unsigned char* FilePtr;
+    long lBufferSizeCpr;
+    long lBufferSizeUncpr;
+    long lCompressedSize=0;
+    unsigned char* CprPtr;
+    unsigned char* UncprPtr;
+    long lSizeCpr,lSizeUncpr;
+    DWORD dwGetTick,dwMsecQP;
+    LARGE_INTEGER li_qp,li_rdtsc,dwResRdtsc;
+
+    if (argc<=1)
+    {
+        printf("run TestZlib <File> [BlockSizeCompress] [BlockSizeUncompress] [compres. level]\n");
+        return 0;
+    }
+
+    if (ReadFileMemory(argv[1],&lFileSize,&FilePtr)==0)
+    {
+        printf("error reading %s\n",argv[1]);
+        return 1;
+    }
+    else printf("file %s read, %u bytes\n",argv[1],lFileSize);
+
+    if (argc>=3)
+        BlockSizeCompress=atol(argv[2]);
+
+    if (argc>=4)
+        BlockSizeUncompress=atol(argv[3]);
+
+    if (argc>=5)
+        cprLevel=(int)atol(argv[4]);
+
+    lBufferSizeCpr = lFileSize + (lFileSize/0x10) + 0x200;
+    lBufferSizeUncpr = lBufferSizeCpr;
+
+    CprPtr=(unsigned char*)malloc(lBufferSizeCpr + BlockSizeCompress);
+
+    BeginCountPerfCounter(&li_qp,TRUE);
+    dwGetTick=GetTickCount();
+    BeginCountRdtsc(&li_rdtsc);
+    {
+        z_stream zcpr;
+        int ret=Z_OK;
+        long lOrigToDo = lFileSize;
+        long lOrigDone = 0;
+        int step=0;
+        memset(&zcpr,0,sizeof(z_stream));
+        deflateInit(&zcpr,cprLevel);
+
+        zcpr.next_in = FilePtr;
+        zcpr.next_out = CprPtr;
+
+
+        do
+        {
+            long all_read_before = zcpr.total_in;
+            zcpr.avail_in = min(lOrigToDo,BlockSizeCompress);
+            zcpr.avail_out = BlockSizeCompress;
+            ret=deflate(&zcpr,(zcpr.avail_in==lOrigToDo) ? Z_FINISH : Z_SYNC_FLUSH);
+            lOrigDone += (zcpr.total_in-all_read_before);
+            lOrigToDo -= (zcpr.total_in-all_read_before);
+            step++;
+        } while (ret==Z_OK);
+
+        lSizeCpr=zcpr.total_out;
+        deflateEnd(&zcpr);
+        dwGetTick=GetTickCount()-dwGetTick;
+        dwMsecQP=GetMsecSincePerfCounter(li_qp,TRUE);
+        dwResRdtsc=GetResRdtsc(li_rdtsc,TRUE);
+        printf("total compress size = %u, in %u step\n",lSizeCpr,step);
+        printf("time = %u msec = %f sec\n",dwGetTick,dwGetTick/(double)1000.);
+        printf("defcpr time QP = %u msec = %f sec\n",dwMsecQP,dwMsecQP/(double)1000.);
+        printf("defcpr result rdtsc = %I64x\n\n",dwResRdtsc.QuadPart);
+    }
+
+    CprPtr=(unsigned char*)realloc(CprPtr,lSizeCpr);
+    UncprPtr=(unsigned char*)malloc(lBufferSizeUncpr + BlockSizeUncompress);
+
+    BeginCountPerfCounter(&li_qp,TRUE);
+    dwGetTick=GetTickCount();
+    BeginCountRdtsc(&li_rdtsc);
+    {
+        z_stream zcpr;
+        int ret=Z_OK;
+        long lOrigToDo = lSizeCpr;
+        long lOrigDone = 0;
+        int step=0;
+        memset(&zcpr,0,sizeof(z_stream));
+        inflateInit(&zcpr);
+
+        zcpr.next_in = CprPtr;
+        zcpr.next_out = UncprPtr;
+
+
+        do
+        {
+            long all_read_before = zcpr.total_in;
+            zcpr.avail_in = min(lOrigToDo,BlockSizeUncompress);
+            zcpr.avail_out = BlockSizeUncompress;
+            ret=inflate(&zcpr,Z_SYNC_FLUSH);
+            lOrigDone += (zcpr.total_in-all_read_before);
+            lOrigToDo -= (zcpr.total_in-all_read_before);
+            step++;
+        } while (ret==Z_OK);
+
+        lSizeUncpr=zcpr.total_out;
+        inflateEnd(&zcpr);
+        dwGetTick=GetTickCount()-dwGetTick;
+        dwMsecQP=GetMsecSincePerfCounter(li_qp,TRUE);
+        dwResRdtsc=GetResRdtsc(li_rdtsc,TRUE);
+        printf("total uncompress size = %u, in %u step\n",lSizeUncpr,step);
+        printf("time = %u msec = %f sec\n",dwGetTick,dwGetTick/(double)1000.);
+        printf("uncpr  time QP = %u msec = %f sec\n",dwMsecQP,dwMsecQP/(double)1000.);
+        printf("uncpr  result rdtsc = %I64x\n\n",dwResRdtsc.QuadPart);
+    }
+
+    if (lSizeUncpr==lFileSize)
+    {
+        if (memcmp(FilePtr,UncprPtr,lFileSize)==0)
+            printf("compare ok\n");
+
+    }
+
+    return 0;
+}
diff --git a/xs/src/png/zlib/contrib/testzlib/testzlib.txt b/xs/src/png/zlib/contrib/testzlib/testzlib.txt
new file mode 100644
index 000000000..e508bb22f
--- /dev/null
+++ b/xs/src/png/zlib/contrib/testzlib/testzlib.txt
@@ -0,0 +1,10 @@
+To build testzLib with Visual Studio 2005:
+
+copy to a directory file from :
+- root of zLib tree
+- contrib/testzlib
+- contrib/masmx86
+- contrib/masmx64
+- contrib/vstudio/vc7
+
+and open testzlib8.sln
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/untgz/Makefile b/xs/src/png/zlib/contrib/untgz/Makefile
new file mode 100644
index 000000000..b54266fba
--- /dev/null
+++ b/xs/src/png/zlib/contrib/untgz/Makefile
@@ -0,0 +1,14 @@
+CC=cc
+CFLAGS=-g
+
+untgz: untgz.o ../../libz.a
+	$(CC) $(CFLAGS) -o untgz untgz.o -L../.. -lz
+
+untgz.o: untgz.c ../../zlib.h
+	$(CC) $(CFLAGS) -c -I../.. untgz.c
+
+../../libz.a:
+	cd ../..; ./configure; make
+
+clean:
+	rm -f untgz untgz.o *~
diff --git a/xs/src/png/zlib/contrib/untgz/Makefile.msc b/xs/src/png/zlib/contrib/untgz/Makefile.msc
new file mode 100644
index 000000000..77b860221
--- /dev/null
+++ b/xs/src/png/zlib/contrib/untgz/Makefile.msc
@@ -0,0 +1,17 @@
+CC=cl
+CFLAGS=-MD
+
+untgz.exe: untgz.obj ..\..\zlib.lib
+	$(CC) $(CFLAGS) untgz.obj ..\..\zlib.lib
+
+untgz.obj: untgz.c ..\..\zlib.h
+	$(CC) $(CFLAGS) -c -I..\.. untgz.c
+
+..\..\zlib.lib:
+	cd ..\..
+	$(MAKE) -f win32\makefile.msc
+	cd contrib\untgz
+
+clean:
+	-del untgz.obj
+	-del untgz.exe
diff --git a/xs/src/png/zlib/contrib/untgz/untgz.c b/xs/src/png/zlib/contrib/untgz/untgz.c
new file mode 100644
index 000000000..2c391e598
--- /dev/null
+++ b/xs/src/png/zlib/contrib/untgz/untgz.c
@@ -0,0 +1,674 @@
+/*
+ * untgz.c -- Display contents and extract files from a gzip'd TAR file
+ *
+ * written by Pedro A. Aranda Gutierrez <paag@tid.es>
+ * adaptation to Unix by Jean-loup Gailly <jloup@gzip.org>
+ * various fixes by Cosmin Truta <cosmint@cs.ubbcluj.ro>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+
+#include "zlib.h"
+
+#ifdef unix
+#  include <unistd.h>
+#else
+#  include <direct.h>
+#  include <io.h>
+#endif
+
+#ifdef WIN32
+#include <windows.h>
+#  ifndef F_OK
+#    define F_OK  0
+#  endif
+#  define mkdir(dirname,mode)   _mkdir(dirname)
+#  ifdef _MSC_VER
+#    define access(path,mode)   _access(path,mode)
+#    define chmod(path,mode)    _chmod(path,mode)
+#    define strdup(str)         _strdup(str)
+#  endif
+#else
+#  include <utime.h>
+#endif
+
+
+/* values used in typeflag field */
+
+#define REGTYPE  '0'            /* regular file */
+#define AREGTYPE '\0'           /* regular file */
+#define LNKTYPE  '1'            /* link */
+#define SYMTYPE  '2'            /* reserved */
+#define CHRTYPE  '3'            /* character special */
+#define BLKTYPE  '4'            /* block special */
+#define DIRTYPE  '5'            /* directory */
+#define FIFOTYPE '6'            /* FIFO special */
+#define CONTTYPE '7'            /* reserved */
+
+/* GNU tar extensions */
+
+#define GNUTYPE_DUMPDIR  'D'    /* file names from dumped directory */
+#define GNUTYPE_LONGLINK 'K'    /* long link name */
+#define GNUTYPE_LONGNAME 'L'    /* long file name */
+#define GNUTYPE_MULTIVOL 'M'    /* continuation of file from another volume */
+#define GNUTYPE_NAMES    'N'    /* file name that does not fit into main hdr */
+#define GNUTYPE_SPARSE   'S'    /* sparse file */
+#define GNUTYPE_VOLHDR   'V'    /* tape/volume header */
+
+
+/* tar header */
+
+#define BLOCKSIZE     512
+#define SHORTNAMESIZE 100
+
+struct tar_header
+{                               /* byte offset */
+  char name[100];               /*   0 */
+  char mode[8];                 /* 100 */
+  char uid[8];                  /* 108 */
+  char gid[8];                  /* 116 */
+  char size[12];                /* 124 */
+  char mtime[12];               /* 136 */
+  char chksum[8];               /* 148 */
+  char typeflag;                /* 156 */
+  char linkname[100];           /* 157 */
+  char magic[6];                /* 257 */
+  char version[2];              /* 263 */
+  char uname[32];               /* 265 */
+  char gname[32];               /* 297 */
+  char devmajor[8];             /* 329 */
+  char devminor[8];             /* 337 */
+  char prefix[155];             /* 345 */
+                                /* 500 */
+};
+
+union tar_buffer
+{
+  char               buffer[BLOCKSIZE];
+  struct tar_header  header;
+};
+
+struct attr_item
+{
+  struct attr_item  *next;
+  char              *fname;
+  int                mode;
+  time_t             time;
+};
+
+enum { TGZ_EXTRACT, TGZ_LIST, TGZ_INVALID };
+
+char *TGZfname          OF((const char *));
+void TGZnotfound        OF((const char *));
+
+int getoct              OF((char *, int));
+char *strtime           OF((time_t *));
+int setfiletime         OF((char *, time_t));
+void push_attr          OF((struct attr_item **, char *, int, time_t));
+void restore_attr       OF((struct attr_item **));
+
+int ExprMatch           OF((char *, char *));
+
+int makedir             OF((char *));
+int matchname           OF((int, int, char **, char *));
+
+void error              OF((const char *));
+int tar                 OF((gzFile, int, int, int, char **));
+
+void help               OF((int));
+int main                OF((int, char **));
+
+char *prog;
+
+const char *TGZsuffix[] = { "\0", ".tar", ".tar.gz", ".taz", ".tgz", NULL };
+
+/* return the file name of the TGZ archive */
+/* or NULL if it does not exist */
+
+char *TGZfname (const char *arcname)
+{
+  static char buffer[1024];
+  int origlen,i;
+
+  strcpy(buffer,arcname);
+  origlen = strlen(buffer);
+
+  for (i=0; TGZsuffix[i]; i++)
+    {
+       strcpy(buffer+origlen,TGZsuffix[i]);
+       if (access(buffer,F_OK) == 0)
+         return buffer;
+    }
+  return NULL;
+}
+
+
+/* error message for the filename */
+
+void TGZnotfound (const char *arcname)
+{
+  int i;
+
+  fprintf(stderr,"%s: Couldn't find ",prog);
+  for (i=0;TGZsuffix[i];i++)
+    fprintf(stderr,(TGZsuffix[i+1]) ? "%s%s, " : "or %s%s\n",
+            arcname,
+            TGZsuffix[i]);
+  exit(1);
+}
+
+
+/* convert octal digits to int */
+/* on error return -1 */
+
+int getoct (char *p,int width)
+{
+  int result = 0;
+  char c;
+
+  while (width--)
+    {
+      c = *p++;
+      if (c == 0)
+        break;
+      if (c == ' ')
+        continue;
+      if (c < '0' || c > '7')
+        return -1;
+      result = result * 8 + (c - '0');
+    }
+  return result;
+}
+
+
+/* convert time_t to string */
+/* use the "YYYY/MM/DD hh:mm:ss" format */
+
+char *strtime (time_t *t)
+{
+  struct tm   *local;
+  static char result[32];
+
+  local = localtime(t);
+  sprintf(result,"%4d/%02d/%02d %02d:%02d:%02d",
+          local->tm_year+1900, local->tm_mon+1, local->tm_mday,
+          local->tm_hour, local->tm_min, local->tm_sec);
+  return result;
+}
+
+
+/* set file time */
+
+int setfiletime (char *fname,time_t ftime)
+{
+#ifdef WIN32
+  static int isWinNT = -1;
+  SYSTEMTIME st;
+  FILETIME locft, modft;
+  struct tm *loctm;
+  HANDLE hFile;
+  int result;
+
+  loctm = localtime(&ftime);
+  if (loctm == NULL)
+    return -1;
+
+  st.wYear         = (WORD)loctm->tm_year + 1900;
+  st.wMonth        = (WORD)loctm->tm_mon + 1;
+  st.wDayOfWeek    = (WORD)loctm->tm_wday;
+  st.wDay          = (WORD)loctm->tm_mday;
+  st.wHour         = (WORD)loctm->tm_hour;
+  st.wMinute       = (WORD)loctm->tm_min;
+  st.wSecond       = (WORD)loctm->tm_sec;
+  st.wMilliseconds = 0;
+  if (!SystemTimeToFileTime(&st, &locft) ||
+      !LocalFileTimeToFileTime(&locft, &modft))
+    return -1;
+
+  if (isWinNT < 0)
+    isWinNT = (GetVersion() < 0x80000000) ? 1 : 0;
+  hFile = CreateFile(fname, GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
+                     (isWinNT ? FILE_FLAG_BACKUP_SEMANTICS : 0),
+                     NULL);
+  if (hFile == INVALID_HANDLE_VALUE)
+    return -1;
+  result = SetFileTime(hFile, NULL, NULL, &modft) ? 0 : -1;
+  CloseHandle(hFile);
+  return result;
+#else
+  struct utimbuf settime;
+
+  settime.actime = settime.modtime = ftime;
+  return utime(fname,&settime);
+#endif
+}
+
+
+/* push file attributes */
+
+void push_attr(struct attr_item **list,char *fname,int mode,time_t time)
+{
+  struct attr_item *item;
+
+  item = (struct attr_item *)malloc(sizeof(struct attr_item));
+  if (item == NULL)
+    error("Out of memory");
+  item->fname = strdup(fname);
+  item->mode  = mode;
+  item->time  = time;
+  item->next  = *list;
+  *list       = item;
+}
+
+
+/* restore file attributes */
+
+void restore_attr(struct attr_item **list)
+{
+  struct attr_item *item, *prev;
+
+  for (item = *list; item != NULL; )
+    {
+      setfiletime(item->fname,item->time);
+      chmod(item->fname,item->mode);
+      prev = item;
+      item = item->next;
+      free(prev);
+    }
+  *list = NULL;
+}
+
+
+/* match regular expression */
+
+#define ISSPECIAL(c) (((c) == '*') || ((c) == '/'))
+
+int ExprMatch (char *string,char *expr)
+{
+  while (1)
+    {
+      if (ISSPECIAL(*expr))
+        {
+          if (*expr == '/')
+            {
+              if (*string != '\\' && *string != '/')
+                return 0;
+              string ++; expr++;
+            }
+          else if (*expr == '*')
+            {
+              if (*expr ++ == 0)
+                return 1;
+              while (*++string != *expr)
+                if (*string == 0)
+                  return 0;
+            }
+        }
+      else
+        {
+          if (*string != *expr)
+            return 0;
+          if (*expr++ == 0)
+            return 1;
+          string++;
+        }
+    }
+}
+
+
+/* recursive mkdir */
+/* abort on ENOENT; ignore other errors like "directory already exists" */
+/* return 1 if OK */
+/*        0 on error */
+
+int makedir (char *newdir)
+{
+  char *buffer = strdup(newdir);
+  char *p;
+  int  len = strlen(buffer);
+
+  if (len <= 0) {
+    free(buffer);
+    return 0;
+  }
+  if (buffer[len-1] == '/') {
+    buffer[len-1] = '\0';
+  }
+  if (mkdir(buffer, 0755) == 0)
+    {
+      free(buffer);
+      return 1;
+    }
+
+  p = buffer+1;
+  while (1)
+    {
+      char hold;
+
+      while(*p && *p != '\\' && *p != '/')
+        p++;
+      hold = *p;
+      *p = 0;
+      if ((mkdir(buffer, 0755) == -1) && (errno == ENOENT))
+        {
+          fprintf(stderr,"%s: Couldn't create directory %s\n",prog,buffer);
+          free(buffer);
+          return 0;
+        }
+      if (hold == 0)
+        break;
+      *p++ = hold;
+    }
+  free(buffer);
+  return 1;
+}
+
+
+int matchname (int arg,int argc,char **argv,char *fname)
+{
+  if (arg == argc)      /* no arguments given (untgz tgzarchive) */
+    return 1;
+
+  while (arg < argc)
+    if (ExprMatch(fname,argv[arg++]))
+      return 1;
+
+  return 0; /* ignore this for the moment being */
+}
+
+
+/* tar file list or extract */
+
+int tar (gzFile in,int action,int arg,int argc,char **argv)
+{
+  union  tar_buffer buffer;
+  int    len;
+  int    err;
+  int    getheader = 1;
+  int    remaining = 0;
+  FILE   *outfile = NULL;
+  char   fname[BLOCKSIZE];
+  int    tarmode;
+  time_t tartime;
+  struct attr_item *attributes = NULL;
+
+  if (action == TGZ_LIST)
+    printf("    date      time     size                       file\n"
+           " ---------- -------- --------- -------------------------------------\n");
+  while (1)
+    {
+      len = gzread(in, &buffer, BLOCKSIZE);
+      if (len < 0)
+        error(gzerror(in, &err));
+      /*
+       * Always expect complete blocks to process
+       * the tar information.
+       */
+      if (len != BLOCKSIZE)
+        {
+          action = TGZ_INVALID; /* force error exit */
+          remaining = 0;        /* force I/O cleanup */
+        }
+
+      /*
+       * If we have to get a tar header
+       */
+      if (getheader >= 1)
+        {
+          /*
+           * if we met the end of the tar
+           * or the end-of-tar block,
+           * we are done
+           */
+          if (len == 0 || buffer.header.name[0] == 0)
+            break;
+
+          tarmode = getoct(buffer.header.mode,8);
+          tartime = (time_t)getoct(buffer.header.mtime,12);
+          if (tarmode == -1 || tartime == (time_t)-1)
+            {
+              buffer.header.name[0] = 0;
+              action = TGZ_INVALID;
+            }
+
+          if (getheader == 1)
+            {
+              strncpy(fname,buffer.header.name,SHORTNAMESIZE);
+              if (fname[SHORTNAMESIZE-1] != 0)
+                  fname[SHORTNAMESIZE] = 0;
+            }
+          else
+            {
+              /*
+               * The file name is longer than SHORTNAMESIZE
+               */
+              if (strncmp(fname,buffer.header.name,SHORTNAMESIZE-1) != 0)
+                  error("bad long name");
+              getheader = 1;
+            }
+
+          /*
+           * Act according to the type flag
+           */
+          switch (buffer.header.typeflag)
+            {
+            case DIRTYPE:
+              if (action == TGZ_LIST)
+                printf(" %s     <dir> %s\n",strtime(&tartime),fname);
+              if (action == TGZ_EXTRACT)
+                {
+                  makedir(fname);
+                  push_attr(&attributes,fname,tarmode,tartime);
+                }
+              break;
+            case REGTYPE:
+            case AREGTYPE:
+              remaining = getoct(buffer.header.size,12);
+              if (remaining == -1)
+                {
+                  action = TGZ_INVALID;
+                  break;
+                }
+              if (action == TGZ_LIST)
+                printf(" %s %9d %s\n",strtime(&tartime),remaining,fname);
+              else if (action == TGZ_EXTRACT)
+                {
+                  if (matchname(arg,argc,argv,fname))
+                    {
+                      outfile = fopen(fname,"wb");
+                      if (outfile == NULL) {
+                        /* try creating directory */
+                        char *p = strrchr(fname, '/');
+                        if (p != NULL) {
+                          *p = '\0';
+                          makedir(fname);
+                          *p = '/';
+                          outfile = fopen(fname,"wb");
+                        }
+                      }
+                      if (outfile != NULL)
+                        printf("Extracting %s\n",fname);
+                      else
+                        fprintf(stderr, "%s: Couldn't create %s",prog,fname);
+                    }
+                  else
+                    outfile = NULL;
+                }
+              getheader = 0;
+              break;
+            case GNUTYPE_LONGLINK:
+            case GNUTYPE_LONGNAME:
+              remaining = getoct(buffer.header.size,12);
+              if (remaining < 0 || remaining >= BLOCKSIZE)
+                {
+                  action = TGZ_INVALID;
+                  break;
+                }
+              len = gzread(in, fname, BLOCKSIZE);
+              if (len < 0)
+                error(gzerror(in, &err));
+              if (fname[BLOCKSIZE-1] != 0 || (int)strlen(fname) > remaining)
+                {
+                  action = TGZ_INVALID;
+                  break;
+                }
+              getheader = 2;
+              break;
+            default:
+              if (action == TGZ_LIST)
+                printf(" %s     <---> %s\n",strtime(&tartime),fname);
+              break;
+            }
+        }
+      else
+        {
+          unsigned int bytes = (remaining > BLOCKSIZE) ? BLOCKSIZE : remaining;
+
+          if (outfile != NULL)
+            {
+              if (fwrite(&buffer,sizeof(char),bytes,outfile) != bytes)
+                {
+                  fprintf(stderr,
+                    "%s: Error writing %s -- skipping\n",prog,fname);
+                  fclose(outfile);
+                  outfile = NULL;
+                  remove(fname);
+                }
+            }
+          remaining -= bytes;
+        }
+
+      if (remaining == 0)
+        {
+          getheader = 1;
+          if (outfile != NULL)
+            {
+              fclose(outfile);
+              outfile = NULL;
+              if (action != TGZ_INVALID)
+                push_attr(&attributes,fname,tarmode,tartime);
+            }
+        }
+
+      /*
+       * Abandon if errors are found
+       */
+      if (action == TGZ_INVALID)
+        {
+          error("broken archive");
+          break;
+        }
+    }
+
+  /*
+   * Restore file modes and time stamps
+   */
+  restore_attr(&attributes);
+
+  if (gzclose(in) != Z_OK)
+    error("failed gzclose");
+
+  return 0;
+}
+
+
+/* ============================================================ */
+
+void help(int exitval)
+{
+  printf("untgz version 0.2.1\n"
+         "  using zlib version %s\n\n",
+         zlibVersion());
+  printf("Usage: untgz file.tgz            extract all files\n"
+         "       untgz file.tgz fname ...  extract selected files\n"
+         "       untgz -l file.tgz         list archive contents\n"
+         "       untgz -h                  display this help\n");
+  exit(exitval);
+}
+
+void error(const char *msg)
+{
+  fprintf(stderr, "%s: %s\n", prog, msg);
+  exit(1);
+}
+
+
+/* ============================================================ */
+
+#if defined(WIN32) && defined(__GNUC__)
+int _CRT_glob = 0;      /* disable argument globbing in MinGW */
+#endif
+
+int main(int argc,char **argv)
+{
+    int         action = TGZ_EXTRACT;
+    int         arg = 1;
+    char        *TGZfile;
+    gzFile      *f;
+
+    prog = strrchr(argv[0],'\\');
+    if (prog == NULL)
+      {
+        prog = strrchr(argv[0],'/');
+        if (prog == NULL)
+          {
+            prog = strrchr(argv[0],':');
+            if (prog == NULL)
+              prog = argv[0];
+            else
+              prog++;
+          }
+        else
+          prog++;
+      }
+    else
+      prog++;
+
+    if (argc == 1)
+      help(0);
+
+    if (strcmp(argv[arg],"-l") == 0)
+      {
+        action = TGZ_LIST;
+        if (argc == ++arg)
+          help(0);
+      }
+    else if (strcmp(argv[arg],"-h") == 0)
+      {
+        help(0);
+      }
+
+    if ((TGZfile = TGZfname(argv[arg])) == NULL)
+      TGZnotfound(argv[arg]);
+
+    ++arg;
+    if ((action == TGZ_LIST) && (arg != argc))
+      help(1);
+
+/*
+ *  Process the TGZ file
+ */
+    switch(action)
+      {
+      case TGZ_LIST:
+      case TGZ_EXTRACT:
+        f = gzopen(TGZfile,"rb");
+        if (f == NULL)
+          {
+            fprintf(stderr,"%s: Couldn't gzopen %s\n",prog,TGZfile);
+            return 1;
+          }
+        exit(tar(f, action, arg, argc, argv));
+      break;
+
+      default:
+        error("Unknown option");
+        exit(1);
+      }
+
+    return 0;
+}
diff --git a/xs/src/png/zlib/contrib/vstudio/readme.txt b/xs/src/png/zlib/contrib/vstudio/readme.txt
new file mode 100644
index 000000000..48cccc0d2
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/readme.txt
@@ -0,0 +1,78 @@
+Building instructions for the DLL versions of Zlib 1.2.11
+========================================================
+
+This directory contains projects that build zlib and minizip using
+Microsoft Visual C++ 9.0/10.0.
+
+You don't need to build these projects yourself. You can download the
+binaries from:
+  http://www.winimage.com/zLibDll
+
+More information can be found at this site.
+
+
+
+
+
+Build instructions for Visual Studio 2008 (32 bits or 64 bits)
+--------------------------------------------------------------
+- Decompress current zlib, including all contrib/* files
+- Compile assembly code (with Visual Studio Command Prompt) by running:
+   bld_ml64.bat (in contrib\masmx64)
+   bld_ml32.bat (in contrib\masmx86)
+- Open contrib\vstudio\vc9\zlibvc.sln with Microsoft Visual C++ 2008
+- Or run: vcbuild /rebuild contrib\vstudio\vc9\zlibvc.sln "Release|Win32"
+
+Build instructions for Visual Studio 2010 (32 bits or 64 bits)
+--------------------------------------------------------------
+- Decompress current zlib, including all contrib/* files
+- Open contrib\vstudio\vc10\zlibvc.sln with Microsoft Visual C++ 2010
+
+Build instructions for Visual Studio 2012 (32 bits or 64 bits)
+--------------------------------------------------------------
+- Decompress current zlib, including all contrib/* files
+- Open contrib\vstudio\vc11\zlibvc.sln with Microsoft Visual C++ 2012
+
+Build instructions for Visual Studio 2013 (32 bits or 64 bits)
+--------------------------------------------------------------
+- Decompress current zlib, including all contrib/* files
+- Open contrib\vstudio\vc12\zlibvc.sln with Microsoft Visual C++ 2013
+
+Build instructions for Visual Studio 2015 (32 bits or 64 bits)
+--------------------------------------------------------------
+- Decompress current zlib, including all contrib/* files
+- Open contrib\vstudio\vc14\zlibvc.sln with Microsoft Visual C++ 2015
+
+
+Important
+---------
+- To use zlibwapi.dll in your application, you must define the
+  macro ZLIB_WINAPI when compiling your application's source files.
+
+
+Additional notes
+----------------
+- This DLL, named zlibwapi.dll, is compatible to the old zlib.dll built
+  by Gilles Vollant from the zlib 1.1.x sources, and distributed at
+    http://www.winimage.com/zLibDll
+  It uses the WINAPI calling convention for the exported functions, and
+  includes the minizip functionality. If your application needs that
+  particular build of zlib.dll, you can rename zlibwapi.dll to zlib.dll.
+
+- The new DLL was renamed because there exist several incompatible
+  versions of zlib.dll on the Internet.
+
+- There is also an official DLL build of zlib, named zlib1.dll. This one
+  is exporting the functions using the CDECL convention. See the file
+  win32\DLL_FAQ.txt found in this zlib distribution.
+
+- There used to be a ZLIB_DLL macro in zlib 1.1.x, but now this symbol
+  has a slightly different effect. To avoid compatibility problems, do
+  not define it here.
+
+
+Gilles Vollant
+info@winimage.com
+
+Visual Studio 2013 and 2015 Projects from Sean Hunt
+seandhunt_7@yahoo.com
diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/miniunz.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc10/miniunz.vcxproj
new file mode 100644
index 000000000..1b3624215
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/miniunz.vcxproj
@@ -0,0 +1,310 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Itanium">
+      <Configuration>Debug</Configuration>
+      <Platform>Itanium</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
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+      <RandomizedBaseAddress>false</RandomizedBaseAddress>
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/testzlibdll.vcxproj.filters b/xs/src/png/zlib/contrib/vstudio/vc10/testzlibdll.vcxproj.filters
new file mode 100644
index 000000000..ab87f09f4
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/testzlibdll.vcxproj.filters
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="Source Files">
+      <UniqueIdentifier>{fa61a89f-93fc-4c89-b29e-36224b7592f4}</UniqueIdentifier>
+      <Extensions>cpp;c;cxx;def;odl;idl;hpj;bat;asm</Extensions>
+    </Filter>
+    <Filter Include="Header Files">
+      <UniqueIdentifier>{d4b85da0-2ba2-4934-b57f-e2584e3848ee}</UniqueIdentifier>
+      <Extensions>h;hpp;hxx;hm;inl;inc</Extensions>
+    </Filter>
+    <Filter Include="Resource Files">
+      <UniqueIdentifier>{e573e075-00bd-4a7d-bd67-a8cc9bfc5aca}</UniqueIdentifier>
+      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe</Extensions>
+    </Filter>
+  </ItemGroup>
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+    <ClCompile Include="..\..\testzlib\testzlib.c">
+      <Filter>Source Files</Filter>
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+  </ItemGroup>
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/zlib.rc b/xs/src/png/zlib/contrib/vstudio/vc10/zlib.rc
new file mode 100644
index 000000000..c4e4b016e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/zlib.rc
@@ -0,0 +1,32 @@
+#include <windows.h>
+
+#define IDR_VERSION1  1
+IDR_VERSION1	VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+  FILEVERSION	 1, 2, 11, 0
+  PRODUCTVERSION 1, 2, 11, 0
+  FILEFLAGSMASK	VS_FFI_FILEFLAGSMASK
+  FILEFLAGS	0
+  FILEOS	VOS_DOS_WINDOWS32
+  FILETYPE	VFT_DLL
+  FILESUBTYPE	0	// not used
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+
+    BEGIN
+      VALUE "FileDescription", "zlib data compression and ZIP file I/O library\0"
+      VALUE "FileVersion",	"1.2.11\0"
+      VALUE "InternalName",	"zlib\0"
+      VALUE "OriginalFilename",	"zlibwapi.dll\0"
+      VALUE "ProductName",	"ZLib.DLL\0"
+      VALUE "Comments","DLL support by Alessandro Iacopetti & Gilles Vollant\0"
+      VALUE "LegalCopyright", "(C) 1995-2017 Jean-loup Gailly & Mark Adler\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END
diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/zlibstat.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc10/zlibstat.vcxproj
new file mode 100644
index 000000000..45389a352
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/zlibstat.vcxproj
@@ -0,0 +1,473 @@
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+  <PropertyGroup>
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+    <CodeAnalysisRuleAssemblies Condition="'$(Configuration)|$(Platform)'=='Release|x64'" />
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+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
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+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>WIN32;ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:X86 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>OldStyle</DebugInformationFormat>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+    <PreBuildEvent>
+      <Command>cd ..\..\masmx64
+bld_ml64.bat</Command>
+    </PreBuildEvent>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>OldStyle</DebugInformationFormat>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ASMV;ASMINF;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalDependencies>..\..\masmx64\gvmat64.obj;..\..\masmx64\inffasx64.obj;%(AdditionalDependencies)</AdditionalDependencies>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+    <PreBuildEvent>
+      <Command>cd ..\..\masmx64
+bld_ml64.bat</Command>
+    </PreBuildEvent>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\adler32.c" />
+    <ClCompile Include="..\..\..\compress.c" />
+    <ClCompile Include="..\..\..\crc32.c" />
+    <ClCompile Include="..\..\..\deflate.c" />
+    <ClCompile Include="..\..\..\gzclose.c" />
+    <ClCompile Include="..\..\..\gzlib.c" />
+    <ClCompile Include="..\..\..\gzread.c" />
+    <ClCompile Include="..\..\..\gzwrite.c" />
+    <ClCompile Include="..\..\..\infback.c" />
+    <ClCompile Include="..\..\masmx64\inffas8664.c">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inffast.c" />
+    <ClCompile Include="..\..\..\inflate.c" />
+    <ClCompile Include="..\..\..\inftrees.c" />
+    <ClCompile Include="..\..\minizip\ioapi.c" />
+    <ClCompile Include="..\..\..\trees.c" />
+    <ClCompile Include="..\..\..\uncompr.c" />
+    <ClCompile Include="..\..\minizip\unzip.c" />
+    <ClCompile Include="..\..\minizip\zip.c" />
+    <ClCompile Include="..\..\..\zutil.c" />
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="zlib.rc" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="zlibvc.def" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/zlibstat.vcxproj.filters b/xs/src/png/zlib/contrib/vstudio/vc10/zlibstat.vcxproj.filters
new file mode 100644
index 000000000..0c8b2501c
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/zlibstat.vcxproj.filters
@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="Source Files">
+      <UniqueIdentifier>{174213f6-7f66-4ae8-a3a8-a1e0a1e6ffdd}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\adler32.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\compress.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\crc32.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\deflate.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\gzclose.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\gzlib.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\gzread.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\gzwrite.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\infback.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\masmx64\inffas8664.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inffast.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inflate.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inftrees.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\minizip\ioapi.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\trees.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\uncompr.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\minizip\unzip.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\minizip\zip.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\zutil.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="zlib.rc">
+      <Filter>Source Files</Filter>
+    </ResourceCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="zlibvc.def">
+      <Filter>Source Files</Filter>
+    </None>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.def b/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.def
new file mode 100644
index 000000000..f876c3bca
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.def
@@ -0,0 +1,153 @@
+LIBRARY
+; zlib data compression and ZIP file I/O library
+
+VERSION		1.2
+
+EXPORTS
+        adler32                                  @1
+        compress                                 @2
+        crc32                                    @3
+        deflate                                  @4
+        deflateCopy                              @5
+        deflateEnd                               @6
+        deflateInit2_                            @7
+        deflateInit_                             @8
+        deflateParams                            @9
+        deflateReset                             @10
+        deflateSetDictionary                     @11
+        gzclose                                  @12
+        gzdopen                                  @13
+        gzerror                                  @14
+        gzflush                                  @15
+        gzopen                                   @16
+        gzread                                   @17
+        gzwrite                                  @18
+        inflate                                  @19
+        inflateEnd                               @20
+        inflateInit2_                            @21
+        inflateInit_                             @22
+        inflateReset                             @23
+        inflateSetDictionary                     @24
+        inflateSync                              @25
+        uncompress                               @26
+        zlibVersion                              @27
+        gzprintf                                 @28
+        gzputc                                   @29
+        gzgetc                                   @30
+        gzseek                                   @31
+        gzrewind                                 @32
+        gztell                                   @33
+        gzeof                                    @34
+        gzsetparams                              @35
+        zError                                   @36
+        inflateSyncPoint                         @37
+        get_crc_table                            @38
+        compress2                                @39
+        gzputs                                   @40
+        gzgets                                   @41
+        inflateCopy                              @42
+        inflateBackInit_                         @43
+        inflateBack                              @44
+        inflateBackEnd                           @45
+        compressBound                            @46
+        deflateBound                             @47
+        gzclearerr                               @48
+        gzungetc                                 @49
+        zlibCompileFlags                         @50
+        deflatePrime                             @51
+        deflatePending                           @52
+
+        unzOpen                                  @61
+        unzClose                                 @62
+        unzGetGlobalInfo                         @63
+        unzGetCurrentFileInfo                    @64
+        unzGoToFirstFile                         @65
+        unzGoToNextFile                          @66
+        unzOpenCurrentFile                       @67
+        unzReadCurrentFile                       @68
+        unzOpenCurrentFile3                      @69
+        unztell                                  @70
+        unzeof                                   @71
+        unzCloseCurrentFile                      @72
+        unzGetGlobalComment                      @73
+        unzStringFileNameCompare                 @74
+        unzLocateFile                            @75
+        unzGetLocalExtrafield                    @76
+        unzOpen2                                 @77
+        unzOpenCurrentFile2                      @78
+        unzOpenCurrentFilePassword               @79
+
+        zipOpen                                  @80
+        zipOpenNewFileInZip                      @81
+        zipWriteInFileInZip                      @82
+        zipCloseFileInZip                        @83
+        zipClose                                 @84
+        zipOpenNewFileInZip2                     @86
+        zipCloseFileInZipRaw                     @87
+        zipOpen2                                 @88
+        zipOpenNewFileInZip3                     @89
+
+        unzGetFilePos                            @100
+        unzGoToFilePos                           @101
+
+        fill_win32_filefunc                      @110
+
+; zlibwapi v1.2.4 added:
+        fill_win32_filefunc64                   @111
+        fill_win32_filefunc64A                  @112
+        fill_win32_filefunc64W                  @113
+
+        unzOpen64                               @120
+        unzOpen2_64                             @121
+        unzGetGlobalInfo64                      @122
+        unzGetCurrentFileInfo64                 @124
+        unzGetCurrentFileZStreamPos64           @125
+        unztell64                               @126
+        unzGetFilePos64                         @127
+        unzGoToFilePos64                        @128
+
+        zipOpen64                               @130
+        zipOpen2_64                             @131
+        zipOpenNewFileInZip64                   @132
+        zipOpenNewFileInZip2_64                 @133
+        zipOpenNewFileInZip3_64                 @134
+        zipOpenNewFileInZip4_64                 @135
+        zipCloseFileInZipRaw64                  @136
+
+; zlib1 v1.2.4 added:
+        adler32_combine                         @140
+        crc32_combine                           @142
+        deflateSetHeader                        @144
+        deflateTune                             @145
+        gzbuffer                                @146
+        gzclose_r                               @147
+        gzclose_w                               @148
+        gzdirect                                @149
+        gzoffset                                @150
+        inflateGetHeader                        @156
+        inflateMark                             @157
+        inflatePrime                            @158
+        inflateReset2                           @159
+        inflateUndermine                        @160
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @161
+        inflateResetKeep                        @163
+        deflateResetKeep                        @164
+
+; zlib1 v1.2.7 added:
+        gzopen_w                                @165
+
+; zlib1 v1.2.8 added:
+        inflateGetDictionary                    @166
+        gzvprintf                               @167
+
+; zlib1 v1.2.9 added:
+        inflateCodesUsed                        @168
+        inflateValidate                         @169
+        uncompress2                             @170
+        gzfread                                 @171
+        gzfwrite                                @172
+        deflateGetDictionary                    @173
+        adler32_z                               @174
+        crc32_z                                 @175
diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.sln b/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.sln
new file mode 100644
index 000000000..649f40c7e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.sln
@@ -0,0 +1,135 @@
+
+Microsoft Visual Studio Solution File, Format Version 11.00
+# Visual Studio 2010
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibvc", "zlibvc.vcxproj", "{8FD826F8-3739-44E6-8CC8-997122E53B8D}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibstat", "zlibstat.vcxproj", "{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlib", "testzlib.vcxproj", "{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlibdll", "testzlibdll.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694366A}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "minizip", "minizip.vcxproj", "{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "miniunz", "miniunz.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694382A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Itanium = Debug|Itanium
+		Debug|Win32 = Debug|Win32
+		Debug|x64 = Debug|x64
+		Release|Itanium = Release|Itanium
+		Release|Win32 = Release|Win32
+		Release|x64 = Release|x64
+		ReleaseWithoutAsm|Itanium = ReleaseWithoutAsm|Itanium
+		ReleaseWithoutAsm|Win32 = ReleaseWithoutAsm|Win32
+		ReleaseWithoutAsm|x64 = ReleaseWithoutAsm|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.Build.0 = Debug|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.Build.0 = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.ActiveCfg = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.Build.0 = Debug|x64
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.vcxproj
new file mode 100644
index 000000000..7d7c49a6d
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc10/zlibvc.vcxproj
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new file mode 100644
index 000000000..0115dd17b
--- /dev/null
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc11/testzlibdll.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc11/testzlibdll.vcxproj
new file mode 100644
index 000000000..9d36336eb
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc11/zlib.rc b/xs/src/png/zlib/contrib/vstudio/vc11/zlib.rc
new file mode 100644
index 000000000..c4e4b016e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc11/zlib.rc
@@ -0,0 +1,32 @@
+#include <windows.h>
+
+#define IDR_VERSION1  1
+IDR_VERSION1	VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+  FILEVERSION	 1, 2, 11, 0
+  PRODUCTVERSION 1, 2, 11, 0
+  FILEFLAGSMASK	VS_FFI_FILEFLAGSMASK
+  FILEFLAGS	0
+  FILEOS	VOS_DOS_WINDOWS32
+  FILETYPE	VFT_DLL
+  FILESUBTYPE	0	// not used
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+
+    BEGIN
+      VALUE "FileDescription", "zlib data compression and ZIP file I/O library\0"
+      VALUE "FileVersion",	"1.2.11\0"
+      VALUE "InternalName",	"zlib\0"
+      VALUE "OriginalFilename",	"zlibwapi.dll\0"
+      VALUE "ProductName",	"ZLib.DLL\0"
+      VALUE "Comments","DLL support by Alessandro Iacopetti & Gilles Vollant\0"
+      VALUE "LegalCopyright", "(C) 1995-2017 Jean-loup Gailly & Mark Adler\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END
diff --git a/xs/src/png/zlib/contrib/vstudio/vc11/zlibstat.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc11/zlibstat.vcxproj
new file mode 100644
index 000000000..64b4d869d
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc11/zlibstat.vcxproj
@@ -0,0 +1,464 @@
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+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:X86 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalDependencies>..\..\masmx86\match686.obj;..\..\masmx86\inffas32.obj;%(AdditionalDependencies)</AdditionalDependencies>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Win32'">
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>WIN32;ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:X86 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>OldStyle</DebugInformationFormat>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>OldStyle</DebugInformationFormat>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ASMV;ASMINF;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalDependencies>..\..\masmx64\gvmat64.obj;..\..\masmx64\inffasx64.obj;%(AdditionalDependencies)</AdditionalDependencies>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\adler32.c" />
+    <ClCompile Include="..\..\..\compress.c" />
+    <ClCompile Include="..\..\..\crc32.c" />
+    <ClCompile Include="..\..\..\deflate.c" />
+    <ClCompile Include="..\..\..\gzclose.c" />
+    <ClCompile Include="..\..\..\gzlib.c" />
+    <ClCompile Include="..\..\..\gzread.c" />
+    <ClCompile Include="..\..\..\gzwrite.c" />
+    <ClCompile Include="..\..\..\infback.c" />
+    <ClCompile Include="..\..\masmx64\inffas8664.c">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inffast.c" />
+    <ClCompile Include="..\..\..\inflate.c" />
+    <ClCompile Include="..\..\..\inftrees.c" />
+    <ClCompile Include="..\..\minizip\ioapi.c" />
+    <ClCompile Include="..\..\..\trees.c" />
+    <ClCompile Include="..\..\..\uncompr.c" />
+    <ClCompile Include="..\..\minizip\unzip.c" />
+    <ClCompile Include="..\..\minizip\zip.c" />
+    <ClCompile Include="..\..\..\zutil.c" />
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="zlib.rc" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="zlibvc.def" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.def b/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.def
new file mode 100644
index 000000000..f876c3bca
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.def
@@ -0,0 +1,153 @@
+LIBRARY
+; zlib data compression and ZIP file I/O library
+
+VERSION		1.2
+
+EXPORTS
+        adler32                                  @1
+        compress                                 @2
+        crc32                                    @3
+        deflate                                  @4
+        deflateCopy                              @5
+        deflateEnd                               @6
+        deflateInit2_                            @7
+        deflateInit_                             @8
+        deflateParams                            @9
+        deflateReset                             @10
+        deflateSetDictionary                     @11
+        gzclose                                  @12
+        gzdopen                                  @13
+        gzerror                                  @14
+        gzflush                                  @15
+        gzopen                                   @16
+        gzread                                   @17
+        gzwrite                                  @18
+        inflate                                  @19
+        inflateEnd                               @20
+        inflateInit2_                            @21
+        inflateInit_                             @22
+        inflateReset                             @23
+        inflateSetDictionary                     @24
+        inflateSync                              @25
+        uncompress                               @26
+        zlibVersion                              @27
+        gzprintf                                 @28
+        gzputc                                   @29
+        gzgetc                                   @30
+        gzseek                                   @31
+        gzrewind                                 @32
+        gztell                                   @33
+        gzeof                                    @34
+        gzsetparams                              @35
+        zError                                   @36
+        inflateSyncPoint                         @37
+        get_crc_table                            @38
+        compress2                                @39
+        gzputs                                   @40
+        gzgets                                   @41
+        inflateCopy                              @42
+        inflateBackInit_                         @43
+        inflateBack                              @44
+        inflateBackEnd                           @45
+        compressBound                            @46
+        deflateBound                             @47
+        gzclearerr                               @48
+        gzungetc                                 @49
+        zlibCompileFlags                         @50
+        deflatePrime                             @51
+        deflatePending                           @52
+
+        unzOpen                                  @61
+        unzClose                                 @62
+        unzGetGlobalInfo                         @63
+        unzGetCurrentFileInfo                    @64
+        unzGoToFirstFile                         @65
+        unzGoToNextFile                          @66
+        unzOpenCurrentFile                       @67
+        unzReadCurrentFile                       @68
+        unzOpenCurrentFile3                      @69
+        unztell                                  @70
+        unzeof                                   @71
+        unzCloseCurrentFile                      @72
+        unzGetGlobalComment                      @73
+        unzStringFileNameCompare                 @74
+        unzLocateFile                            @75
+        unzGetLocalExtrafield                    @76
+        unzOpen2                                 @77
+        unzOpenCurrentFile2                      @78
+        unzOpenCurrentFilePassword               @79
+
+        zipOpen                                  @80
+        zipOpenNewFileInZip                      @81
+        zipWriteInFileInZip                      @82
+        zipCloseFileInZip                        @83
+        zipClose                                 @84
+        zipOpenNewFileInZip2                     @86
+        zipCloseFileInZipRaw                     @87
+        zipOpen2                                 @88
+        zipOpenNewFileInZip3                     @89
+
+        unzGetFilePos                            @100
+        unzGoToFilePos                           @101
+
+        fill_win32_filefunc                      @110
+
+; zlibwapi v1.2.4 added:
+        fill_win32_filefunc64                   @111
+        fill_win32_filefunc64A                  @112
+        fill_win32_filefunc64W                  @113
+
+        unzOpen64                               @120
+        unzOpen2_64                             @121
+        unzGetGlobalInfo64                      @122
+        unzGetCurrentFileInfo64                 @124
+        unzGetCurrentFileZStreamPos64           @125
+        unztell64                               @126
+        unzGetFilePos64                         @127
+        unzGoToFilePos64                        @128
+
+        zipOpen64                               @130
+        zipOpen2_64                             @131
+        zipOpenNewFileInZip64                   @132
+        zipOpenNewFileInZip2_64                 @133
+        zipOpenNewFileInZip3_64                 @134
+        zipOpenNewFileInZip4_64                 @135
+        zipCloseFileInZipRaw64                  @136
+
+; zlib1 v1.2.4 added:
+        adler32_combine                         @140
+        crc32_combine                           @142
+        deflateSetHeader                        @144
+        deflateTune                             @145
+        gzbuffer                                @146
+        gzclose_r                               @147
+        gzclose_w                               @148
+        gzdirect                                @149
+        gzoffset                                @150
+        inflateGetHeader                        @156
+        inflateMark                             @157
+        inflatePrime                            @158
+        inflateReset2                           @159
+        inflateUndermine                        @160
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @161
+        inflateResetKeep                        @163
+        deflateResetKeep                        @164
+
+; zlib1 v1.2.7 added:
+        gzopen_w                                @165
+
+; zlib1 v1.2.8 added:
+        inflateGetDictionary                    @166
+        gzvprintf                               @167
+
+; zlib1 v1.2.9 added:
+        inflateCodesUsed                        @168
+        inflateValidate                         @169
+        uncompress2                             @170
+        gzfread                                 @171
+        gzfwrite                                @172
+        deflateGetDictionary                    @173
+        adler32_z                               @174
+        crc32_z                                 @175
diff --git a/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.sln b/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.sln
new file mode 100644
index 000000000..b7e381266
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.sln
@@ -0,0 +1,117 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2012
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibvc", "zlibvc.vcxproj", "{8FD826F8-3739-44E6-8CC8-997122E53B8D}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibstat", "zlibstat.vcxproj", "{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlib", "testzlib.vcxproj", "{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlibdll", "testzlibdll.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694366A}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "minizip", "minizip.vcxproj", "{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "miniunz", "miniunz.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694382A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Itanium = Debug|Itanium
+		Debug|Win32 = Debug|Win32
+		Debug|x64 = Debug|x64
+		Release|Itanium = Release|Itanium
+		Release|Win32 = Release|Win32
+		Release|x64 = Release|x64
+		ReleaseWithoutAsm|Itanium = ReleaseWithoutAsm|Itanium
+		ReleaseWithoutAsm|Win32 = ReleaseWithoutAsm|Win32
+		ReleaseWithoutAsm|x64 = ReleaseWithoutAsm|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.Build.0 = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.ActiveCfg = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.Build.0 = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Itanium.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.Build.0 = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.ActiveCfg = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.Build.0 = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.Build.0 = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.ActiveCfg = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.Build.0 = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Itanium.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.Build.0 = Release|Win32
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.vcxproj
new file mode 100644
index 000000000..c4cffccf1
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc11/zlibvc.vcxproj
@@ -0,0 +1,688 @@
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/miniunz.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc12/miniunz.vcxproj
new file mode 100644
index 000000000..d88ac7fc7
--- /dev/null
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@@ -0,0 +1,316 @@
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index 000000000..f1f239c9e
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new file mode 100644
index 000000000..64b2cbe34
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/testzlibdll.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc12/testzlibdll.vcxproj
new file mode 100644
index 000000000..c66573a8b
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+    <ClCompile>
+      <Optimization>MaxSpeed</Optimization>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <OmitFramePointers>true</OmitFramePointers>
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+      <PreprocessorDefinitions>_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <BasicRuntimeChecks>Default</BasicRuntimeChecks>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <WarningLevel>Level3</WarningLevel>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+    </ClCompile>
+    <Link>
+      <AdditionalDependencies>ia64\ZlibDllRelease\zlibwapi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <OutputFile>$(OutDir)testzlibdll.exe</OutputFile>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <SubSystem>Console</SubSystem>
+      <OptimizeReferences>true</OptimizeReferences>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <TargetMachine>MachineIA64</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\testzlib\testzlib.c" />
+  </ItemGroup>
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+    <ProjectReference Include="zlibvc.vcxproj">
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+    </ProjectReference>
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+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/zlib.rc b/xs/src/png/zlib/contrib/vstudio/vc12/zlib.rc
new file mode 100644
index 000000000..c4e4b016e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc12/zlib.rc
@@ -0,0 +1,32 @@
+#include <windows.h>
+
+#define IDR_VERSION1  1
+IDR_VERSION1	VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+  FILEVERSION	 1, 2, 11, 0
+  PRODUCTVERSION 1, 2, 11, 0
+  FILEFLAGSMASK	VS_FFI_FILEFLAGSMASK
+  FILEFLAGS	0
+  FILEOS	VOS_DOS_WINDOWS32
+  FILETYPE	VFT_DLL
+  FILESUBTYPE	0	// not used
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+
+    BEGIN
+      VALUE "FileDescription", "zlib data compression and ZIP file I/O library\0"
+      VALUE "FileVersion",	"1.2.11\0"
+      VALUE "InternalName",	"zlib\0"
+      VALUE "OriginalFilename",	"zlibwapi.dll\0"
+      VALUE "ProductName",	"ZLib.DLL\0"
+      VALUE "Comments","DLL support by Alessandro Iacopetti & Gilles Vollant\0"
+      VALUE "LegalCopyright", "(C) 1995-2017 Jean-loup Gailly & Mark Adler\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END
diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/zlibstat.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc12/zlibstat.vcxproj
new file mode 100644
index 000000000..3fdee7c50
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc12/zlibstat.vcxproj
@@ -0,0 +1,467 @@
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+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|x64'">
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:AMD64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">
+    <Midl>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibstat.pch</PrecompiledHeaderOutputFile>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Lib>
+      <AdditionalOptions>/MACHINE:IA64 /NODEFAULTLIB %(AdditionalOptions)</AdditionalOptions>
+      <OutputFile>$(OutDir)zlibstat.lib</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </Lib>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\adler32.c" />
+    <ClCompile Include="..\..\..\compress.c" />
+    <ClCompile Include="..\..\..\crc32.c" />
+    <ClCompile Include="..\..\..\deflate.c" />
+    <ClCompile Include="..\..\..\gzclose.c" />
+    <ClCompile Include="..\..\..\gzlib.c" />
+    <ClCompile Include="..\..\..\gzread.c" />
+    <ClCompile Include="..\..\..\gzwrite.c" />
+    <ClCompile Include="..\..\..\infback.c" />
+    <ClCompile Include="..\..\masmx64\inffas8664.c">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inffast.c" />
+    <ClCompile Include="..\..\..\inflate.c" />
+    <ClCompile Include="..\..\..\inftrees.c" />
+    <ClCompile Include="..\..\minizip\ioapi.c" />
+    <ClCompile Include="..\..\..\trees.c" />
+    <ClCompile Include="..\..\..\uncompr.c" />
+    <ClCompile Include="..\..\minizip\unzip.c" />
+    <ClCompile Include="..\..\minizip\zip.c" />
+    <ClCompile Include="..\..\..\zutil.c" />
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="zlib.rc" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="zlibvc.def" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.def b/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.def
new file mode 100644
index 000000000..f876c3bca
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.def
@@ -0,0 +1,153 @@
+LIBRARY
+; zlib data compression and ZIP file I/O library
+
+VERSION		1.2
+
+EXPORTS
+        adler32                                  @1
+        compress                                 @2
+        crc32                                    @3
+        deflate                                  @4
+        deflateCopy                              @5
+        deflateEnd                               @6
+        deflateInit2_                            @7
+        deflateInit_                             @8
+        deflateParams                            @9
+        deflateReset                             @10
+        deflateSetDictionary                     @11
+        gzclose                                  @12
+        gzdopen                                  @13
+        gzerror                                  @14
+        gzflush                                  @15
+        gzopen                                   @16
+        gzread                                   @17
+        gzwrite                                  @18
+        inflate                                  @19
+        inflateEnd                               @20
+        inflateInit2_                            @21
+        inflateInit_                             @22
+        inflateReset                             @23
+        inflateSetDictionary                     @24
+        inflateSync                              @25
+        uncompress                               @26
+        zlibVersion                              @27
+        gzprintf                                 @28
+        gzputc                                   @29
+        gzgetc                                   @30
+        gzseek                                   @31
+        gzrewind                                 @32
+        gztell                                   @33
+        gzeof                                    @34
+        gzsetparams                              @35
+        zError                                   @36
+        inflateSyncPoint                         @37
+        get_crc_table                            @38
+        compress2                                @39
+        gzputs                                   @40
+        gzgets                                   @41
+        inflateCopy                              @42
+        inflateBackInit_                         @43
+        inflateBack                              @44
+        inflateBackEnd                           @45
+        compressBound                            @46
+        deflateBound                             @47
+        gzclearerr                               @48
+        gzungetc                                 @49
+        zlibCompileFlags                         @50
+        deflatePrime                             @51
+        deflatePending                           @52
+
+        unzOpen                                  @61
+        unzClose                                 @62
+        unzGetGlobalInfo                         @63
+        unzGetCurrentFileInfo                    @64
+        unzGoToFirstFile                         @65
+        unzGoToNextFile                          @66
+        unzOpenCurrentFile                       @67
+        unzReadCurrentFile                       @68
+        unzOpenCurrentFile3                      @69
+        unztell                                  @70
+        unzeof                                   @71
+        unzCloseCurrentFile                      @72
+        unzGetGlobalComment                      @73
+        unzStringFileNameCompare                 @74
+        unzLocateFile                            @75
+        unzGetLocalExtrafield                    @76
+        unzOpen2                                 @77
+        unzOpenCurrentFile2                      @78
+        unzOpenCurrentFilePassword               @79
+
+        zipOpen                                  @80
+        zipOpenNewFileInZip                      @81
+        zipWriteInFileInZip                      @82
+        zipCloseFileInZip                        @83
+        zipClose                                 @84
+        zipOpenNewFileInZip2                     @86
+        zipCloseFileInZipRaw                     @87
+        zipOpen2                                 @88
+        zipOpenNewFileInZip3                     @89
+
+        unzGetFilePos                            @100
+        unzGoToFilePos                           @101
+
+        fill_win32_filefunc                      @110
+
+; zlibwapi v1.2.4 added:
+        fill_win32_filefunc64                   @111
+        fill_win32_filefunc64A                  @112
+        fill_win32_filefunc64W                  @113
+
+        unzOpen64                               @120
+        unzOpen2_64                             @121
+        unzGetGlobalInfo64                      @122
+        unzGetCurrentFileInfo64                 @124
+        unzGetCurrentFileZStreamPos64           @125
+        unztell64                               @126
+        unzGetFilePos64                         @127
+        unzGoToFilePos64                        @128
+
+        zipOpen64                               @130
+        zipOpen2_64                             @131
+        zipOpenNewFileInZip64                   @132
+        zipOpenNewFileInZip2_64                 @133
+        zipOpenNewFileInZip3_64                 @134
+        zipOpenNewFileInZip4_64                 @135
+        zipCloseFileInZipRaw64                  @136
+
+; zlib1 v1.2.4 added:
+        adler32_combine                         @140
+        crc32_combine                           @142
+        deflateSetHeader                        @144
+        deflateTune                             @145
+        gzbuffer                                @146
+        gzclose_r                               @147
+        gzclose_w                               @148
+        gzdirect                                @149
+        gzoffset                                @150
+        inflateGetHeader                        @156
+        inflateMark                             @157
+        inflatePrime                            @158
+        inflateReset2                           @159
+        inflateUndermine                        @160
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @161
+        inflateResetKeep                        @163
+        deflateResetKeep                        @164
+
+; zlib1 v1.2.7 added:
+        gzopen_w                                @165
+
+; zlib1 v1.2.8 added:
+        inflateGetDictionary                    @166
+        gzvprintf                               @167
+
+; zlib1 v1.2.9 added:
+        inflateCodesUsed                        @168
+        inflateValidate                         @169
+        uncompress2                             @170
+        gzfread                                 @171
+        gzfwrite                                @172
+        deflateGetDictionary                    @173
+        adler32_z                               @174
+        crc32_z                                 @175
diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.sln b/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.sln
new file mode 100644
index 000000000..dcda22984
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.sln
@@ -0,0 +1,119 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2013
+VisualStudioVersion = 12.0.40629.0
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibvc", "zlibvc.vcxproj", "{8FD826F8-3739-44E6-8CC8-997122E53B8D}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibstat", "zlibstat.vcxproj", "{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlib", "testzlib.vcxproj", "{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlibdll", "testzlibdll.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694366A}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "minizip", "minizip.vcxproj", "{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "miniunz", "miniunz.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694382A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Itanium = Debug|Itanium
+		Debug|Win32 = Debug|Win32
+		Debug|x64 = Debug|x64
+		Release|Itanium = Release|Itanium
+		Release|Win32 = Release|Win32
+		Release|x64 = Release|x64
+		ReleaseWithoutAsm|Itanium = ReleaseWithoutAsm|Itanium
+		ReleaseWithoutAsm|Win32 = ReleaseWithoutAsm|Win32
+		ReleaseWithoutAsm|x64 = ReleaseWithoutAsm|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.Build.0 = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.ActiveCfg = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.Build.0 = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Itanium.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.Build.0 = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.ActiveCfg = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.Build.0 = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.Build.0 = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.ActiveCfg = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.Build.0 = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Itanium.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.Build.0 = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|x64.ActiveCfg = Release|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|x64.Build.0 = Release|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.ActiveCfg = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.Build.0 = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.ActiveCfg = Debug|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.Build.0 = Debug|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.ActiveCfg = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.ActiveCfg = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.Build.0 = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.ActiveCfg = Release|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.Build.0 = Release|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Win32.Build.0 = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|x64.ActiveCfg = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|x64.Build.0 = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Win32.Build.0 = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|x64.Build.0 = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.ActiveCfg = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.Build.0 = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.ActiveCfg = Debug|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.Build.0 = Debug|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.Build.0 = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.ActiveCfg = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.Build.0 = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Win32.Build.0 = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|x64.ActiveCfg = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|x64.Build.0 = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Win32.Build.0 = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|x64.ActiveCfg = Release|x64
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.vcxproj
new file mode 100644
index 000000000..ab2b6c360
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc12/zlibvc.vcxproj
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/miniunz.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc14/miniunz.vcxproj
new file mode 100644
index 000000000..9b5c07587
--- /dev/null
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diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/testzlib.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc14/testzlib.vcxproj
new file mode 100644
index 000000000..2c371252a
--- /dev/null
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+    <ClCompile Include="..\..\..\inflate.c" />
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/testzlibdll.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc14/testzlibdll.vcxproj
new file mode 100644
index 000000000..d87474dec
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc14/testzlibdll.vcxproj
@@ -0,0 +1,316 @@
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/zlib.rc b/xs/src/png/zlib/contrib/vstudio/vc14/zlib.rc
new file mode 100644
index 000000000..c4e4b016e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc14/zlib.rc
@@ -0,0 +1,32 @@
+#include <windows.h>
+
+#define IDR_VERSION1  1
+IDR_VERSION1	VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+  FILEVERSION	 1, 2, 11, 0
+  PRODUCTVERSION 1, 2, 11, 0
+  FILEFLAGSMASK	VS_FFI_FILEFLAGSMASK
+  FILEFLAGS	0
+  FILEOS	VOS_DOS_WINDOWS32
+  FILETYPE	VFT_DLL
+  FILESUBTYPE	0	// not used
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+
+    BEGIN
+      VALUE "FileDescription", "zlib data compression and ZIP file I/O library\0"
+      VALUE "FileVersion",	"1.2.11\0"
+      VALUE "InternalName",	"zlib\0"
+      VALUE "OriginalFilename",	"zlibwapi.dll\0"
+      VALUE "ProductName",	"ZLib.DLL\0"
+      VALUE "Comments","DLL support by Alessandro Iacopetti & Gilles Vollant\0"
+      VALUE "LegalCopyright", "(C) 1995-2017 Jean-loup Gailly & Mark Adler\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END
diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/zlibstat.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc14/zlibstat.vcxproj
new file mode 100644
index 000000000..3e4b98639
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc14/zlibstat.vcxproj
@@ -0,0 +1,467 @@
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\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.def b/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.def
new file mode 100644
index 000000000..f876c3bca
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.def
@@ -0,0 +1,153 @@
+LIBRARY
+; zlib data compression and ZIP file I/O library
+
+VERSION		1.2
+
+EXPORTS
+        adler32                                  @1
+        compress                                 @2
+        crc32                                    @3
+        deflate                                  @4
+        deflateCopy                              @5
+        deflateEnd                               @6
+        deflateInit2_                            @7
+        deflateInit_                             @8
+        deflateParams                            @9
+        deflateReset                             @10
+        deflateSetDictionary                     @11
+        gzclose                                  @12
+        gzdopen                                  @13
+        gzerror                                  @14
+        gzflush                                  @15
+        gzopen                                   @16
+        gzread                                   @17
+        gzwrite                                  @18
+        inflate                                  @19
+        inflateEnd                               @20
+        inflateInit2_                            @21
+        inflateInit_                             @22
+        inflateReset                             @23
+        inflateSetDictionary                     @24
+        inflateSync                              @25
+        uncompress                               @26
+        zlibVersion                              @27
+        gzprintf                                 @28
+        gzputc                                   @29
+        gzgetc                                   @30
+        gzseek                                   @31
+        gzrewind                                 @32
+        gztell                                   @33
+        gzeof                                    @34
+        gzsetparams                              @35
+        zError                                   @36
+        inflateSyncPoint                         @37
+        get_crc_table                            @38
+        compress2                                @39
+        gzputs                                   @40
+        gzgets                                   @41
+        inflateCopy                              @42
+        inflateBackInit_                         @43
+        inflateBack                              @44
+        inflateBackEnd                           @45
+        compressBound                            @46
+        deflateBound                             @47
+        gzclearerr                               @48
+        gzungetc                                 @49
+        zlibCompileFlags                         @50
+        deflatePrime                             @51
+        deflatePending                           @52
+
+        unzOpen                                  @61
+        unzClose                                 @62
+        unzGetGlobalInfo                         @63
+        unzGetCurrentFileInfo                    @64
+        unzGoToFirstFile                         @65
+        unzGoToNextFile                          @66
+        unzOpenCurrentFile                       @67
+        unzReadCurrentFile                       @68
+        unzOpenCurrentFile3                      @69
+        unztell                                  @70
+        unzeof                                   @71
+        unzCloseCurrentFile                      @72
+        unzGetGlobalComment                      @73
+        unzStringFileNameCompare                 @74
+        unzLocateFile                            @75
+        unzGetLocalExtrafield                    @76
+        unzOpen2                                 @77
+        unzOpenCurrentFile2                      @78
+        unzOpenCurrentFilePassword               @79
+
+        zipOpen                                  @80
+        zipOpenNewFileInZip                      @81
+        zipWriteInFileInZip                      @82
+        zipCloseFileInZip                        @83
+        zipClose                                 @84
+        zipOpenNewFileInZip2                     @86
+        zipCloseFileInZipRaw                     @87
+        zipOpen2                                 @88
+        zipOpenNewFileInZip3                     @89
+
+        unzGetFilePos                            @100
+        unzGoToFilePos                           @101
+
+        fill_win32_filefunc                      @110
+
+; zlibwapi v1.2.4 added:
+        fill_win32_filefunc64                   @111
+        fill_win32_filefunc64A                  @112
+        fill_win32_filefunc64W                  @113
+
+        unzOpen64                               @120
+        unzOpen2_64                             @121
+        unzGetGlobalInfo64                      @122
+        unzGetCurrentFileInfo64                 @124
+        unzGetCurrentFileZStreamPos64           @125
+        unztell64                               @126
+        unzGetFilePos64                         @127
+        unzGoToFilePos64                        @128
+
+        zipOpen64                               @130
+        zipOpen2_64                             @131
+        zipOpenNewFileInZip64                   @132
+        zipOpenNewFileInZip2_64                 @133
+        zipOpenNewFileInZip3_64                 @134
+        zipOpenNewFileInZip4_64                 @135
+        zipCloseFileInZipRaw64                  @136
+
+; zlib1 v1.2.4 added:
+        adler32_combine                         @140
+        crc32_combine                           @142
+        deflateSetHeader                        @144
+        deflateTune                             @145
+        gzbuffer                                @146
+        gzclose_r                               @147
+        gzclose_w                               @148
+        gzdirect                                @149
+        gzoffset                                @150
+        inflateGetHeader                        @156
+        inflateMark                             @157
+        inflatePrime                            @158
+        inflateReset2                           @159
+        inflateUndermine                        @160
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @161
+        inflateResetKeep                        @163
+        deflateResetKeep                        @164
+
+; zlib1 v1.2.7 added:
+        gzopen_w                                @165
+
+; zlib1 v1.2.8 added:
+        inflateGetDictionary                    @166
+        gzvprintf                               @167
+
+; zlib1 v1.2.9 added:
+        inflateCodesUsed                        @168
+        inflateValidate                         @169
+        uncompress2                             @170
+        gzfread                                 @171
+        gzfwrite                                @172
+        deflateGetDictionary                    @173
+        adler32_z                               @174
+        crc32_z                                 @175
diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.sln b/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.sln
new file mode 100644
index 000000000..6f4a1076a
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.sln
@@ -0,0 +1,119 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibvc", "zlibvc.vcxproj", "{8FD826F8-3739-44E6-8CC8-997122E53B8D}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibstat", "zlibstat.vcxproj", "{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlib", "testzlib.vcxproj", "{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlibdll", "testzlibdll.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694366A}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "minizip", "minizip.vcxproj", "{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "miniunz", "miniunz.vcxproj", "{C52F9E7B-498A-42BE-8DB4-85A15694382A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Itanium = Debug|Itanium
+		Debug|Win32 = Debug|Win32
+		Debug|x64 = Debug|x64
+		Release|Itanium = Release|Itanium
+		Release|Win32 = Release|Win32
+		Release|x64 = Release|x64
+		ReleaseWithoutAsm|Itanium = ReleaseWithoutAsm|Itanium
+		ReleaseWithoutAsm|Win32 = ReleaseWithoutAsm|Win32
+		ReleaseWithoutAsm|x64 = ReleaseWithoutAsm|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.Build.0 = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.ActiveCfg = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.Build.0 = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Itanium.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.Build.0 = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.ActiveCfg = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.Build.0 = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.Build.0 = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.ActiveCfg = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.Build.0 = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Itanium.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.Build.0 = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|x64.ActiveCfg = Release|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|x64.Build.0 = Release|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.ActiveCfg = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.Build.0 = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.ActiveCfg = Debug|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.Build.0 = Debug|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.ActiveCfg = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.ActiveCfg = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.Build.0 = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.ActiveCfg = Release|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.Build.0 = Release|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Win32.Build.0 = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|x64.ActiveCfg = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|x64.Build.0 = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Win32.Build.0 = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|x64.Build.0 = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.ActiveCfg = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.Build.0 = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.ActiveCfg = Debug|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.Build.0 = Debug|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.Build.0 = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.ActiveCfg = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.Build.0 = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Itanium.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Win32.Build.0 = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|x64.ActiveCfg = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|x64.Build.0 = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Win32.Build.0 = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|x64.Build.0 = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
diff --git a/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.vcxproj b/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.vcxproj
new file mode 100644
index 000000000..f8f673cb0
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc14/zlibvc.vcxproj
@@ -0,0 +1,692 @@
+<?xml version="1.0" encoding="utf-8"?>
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+      <Platform>Itanium</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="ReleaseWithoutAsm|Itanium">
+      <Configuration>ReleaseWithoutAsm</Configuration>
+      <Platform>Itanium</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="ReleaseWithoutAsm|Win32">
+      <Configuration>ReleaseWithoutAsm</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="ReleaseWithoutAsm|x64">
+      <Configuration>ReleaseWithoutAsm</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Itanium">
+      <Configuration>Release</Configuration>
+      <Platform>Itanium</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
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+    <ConfigurationType>DynamicLibrary</ConfigurationType>
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+    <PlatformToolset>v140</PlatformToolset>
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+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <BrowseInformation>
+      </BrowseInformation>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <PreprocessorDefinitions>NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Link>
+      <AdditionalDependencies>..\..\masmx64\gvmat64.obj;..\..\masmx64\inffasx64.obj;%(AdditionalDependencies)</AdditionalDependencies>
+      <OutputFile>$(OutDir)zlibwapi.dll</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
+      <ModuleDefinitionFile>.\zlibvc.def</ModuleDefinitionFile>
+      <ProgramDatabaseFile>$(OutDir)zlibwapi.pdb</ProgramDatabaseFile>
+      <GenerateMapFile>true</GenerateMapFile>
+      <MapFileName>$(OutDir)zlibwapi.map</MapFileName>
+      <SubSystem>Windows</SubSystem>
+      <ImportLibrary>$(OutDir)zlibwapi.lib</ImportLibrary>
+      <TargetMachine>MachineX64</TargetMachine>
+    </Link>
+    <PreBuildEvent>
+      <Command>cd ..\..\masmx64
+bld_ml64.bat</Command>
+    </PreBuildEvent>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">
+    <Midl>
+      <PreprocessorDefinitions>NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <MkTypLibCompatible>true</MkTypLibCompatible>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <TargetEnvironment>Itanium</TargetEnvironment>
+      <TypeLibraryName>$(OutDir)zlibvc.tlb</TypeLibraryName>
+    </Midl>
+    <ClCompile>
+      <InlineFunctionExpansion>OnlyExplicitInline</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\..\..;..\..\masmx86;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;WIN64;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <StringPooling>true</StringPooling>
+      <ExceptionHandling>
+      </ExceptionHandling>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeaderOutputFile>$(IntDir)zlibvc.pch</PrecompiledHeaderOutputFile>
+      <AssemblerOutput>All</AssemblerOutput>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <ObjectFileName>$(IntDir)</ObjectFileName>
+      <ProgramDataBaseFileName>$(OutDir)</ProgramDataBaseFileName>
+      <BrowseInformation>
+      </BrowseInformation>
+      <WarningLevel>Level3</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+    </ClCompile>
+    <ResourceCompile>
+      <PreprocessorDefinitions>NDEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <Culture>0x040c</Culture>
+    </ResourceCompile>
+    <Link>
+      <OutputFile>$(OutDir)zlibwapi.dll</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
+      <ModuleDefinitionFile>.\zlibvc.def</ModuleDefinitionFile>
+      <ProgramDatabaseFile>$(OutDir)zlibwapi.pdb</ProgramDatabaseFile>
+      <GenerateMapFile>true</GenerateMapFile>
+      <MapFileName>$(OutDir)zlibwapi.map</MapFileName>
+      <SubSystem>Windows</SubSystem>
+      <ImportLibrary>$(OutDir)zlibwapi.lib</ImportLibrary>
+      <TargetMachine>MachineIA64</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\adler32.c" />
+    <ClCompile Include="..\..\..\compress.c" />
+    <ClCompile Include="..\..\..\crc32.c" />
+    <ClCompile Include="..\..\..\deflate.c" />
+    <ClCompile Include="..\..\..\gzclose.c" />
+    <ClCompile Include="..\..\..\gzlib.c" />
+    <ClCompile Include="..\..\..\gzread.c" />
+    <ClCompile Include="..\..\..\gzwrite.c" />
+    <ClCompile Include="..\..\..\infback.c" />
+    <ClCompile Include="..\..\masmx64\inffas8664.c">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='ReleaseWithoutAsm|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+    </ClCompile>
+    <ClCompile Include="..\..\..\inffast.c" />
+    <ClCompile Include="..\..\..\inflate.c" />
+    <ClCompile Include="..\..\..\inftrees.c" />
+    <ClCompile Include="..\..\minizip\ioapi.c" />
+    <ClCompile Include="..\..\minizip\iowin32.c" />
+    <ClCompile Include="..\..\..\trees.c" />
+    <ClCompile Include="..\..\..\uncompr.c" />
+    <ClCompile Include="..\..\minizip\unzip.c">
+      <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">ZLIB_INTERNAL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">ZLIB_INTERNAL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Release|x64'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|x64'">ZLIB_INTERNAL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+    </ClCompile>
+    <ClCompile Include="..\..\minizip\zip.c">
+      <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|Itanium'">ZLIB_INTERNAL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">ZLIB_INTERNAL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalIncludeDirectories Condition="'$(Configuration)|$(Platform)'=='Release|x64'">%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions Condition="'$(Configuration)|$(Platform)'=='Release|x64'">ZLIB_INTERNAL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+    </ClCompile>
+    <ClCompile Include="..\..\..\zutil.c" />
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="zlib.rc" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="zlibvc.def" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\..\deflate.h" />
+    <ClInclude Include="..\..\..\infblock.h" />
+    <ClInclude Include="..\..\..\infcodes.h" />
+    <ClInclude Include="..\..\..\inffast.h" />
+    <ClInclude Include="..\..\..\inftrees.h" />
+    <ClInclude Include="..\..\..\infutil.h" />
+    <ClInclude Include="..\..\..\zconf.h" />
+    <ClInclude Include="..\..\..\zlib.h" />
+    <ClInclude Include="..\..\..\zutil.h" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/miniunz.vcproj b/xs/src/png/zlib/contrib/vstudio/vc9/miniunz.vcproj
new file mode 100644
index 000000000..038a9e5fa
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/miniunz.vcproj
@@ -0,0 +1,565 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9.00"
+	Name="miniunz"
+	ProjectGUID="{C52F9E7B-498A-42BE-8DB4-85A15694382A}"
+	Keyword="Win32Proj"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+		<Platform
+			Name="x64"
+		/>
+		<Platform
+			Name="Itanium"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="x86\MiniUnzip$(ConfigurationName)"
+			IntermediateDirectory="x86\MiniUnzip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="1"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="4"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x86\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/miniunz.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/miniunz.pdb"
+				SubSystem="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="x86\MiniUnzip$(ConfigurationName)"
+			IntermediateDirectory="x86\MiniUnzip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x86\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/miniunz.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|x64"
+			OutputDirectory="x64\MiniUnzip$(ConfigurationName)"
+			IntermediateDirectory="x64\MiniUnzip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x64\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/miniunz.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/miniunz.pdb"
+				SubSystem="1"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|Itanium"
+			OutputDirectory="ia64\MiniUnzip$(ConfigurationName)"
+			IntermediateDirectory="ia64\MiniUnzip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="ia64\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/miniunz.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/miniunz.pdb"
+				SubSystem="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|x64"
+			OutputDirectory="x64\MiniUnzip$(ConfigurationName)"
+			IntermediateDirectory="x64\MiniUnzip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x64\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/miniunz.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Itanium"
+			OutputDirectory="ia64\MiniUnzip$(ConfigurationName)"
+			IntermediateDirectory="ia64\MiniUnzip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64"
+				StringPooling="true"
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+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="ia64\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/miniunz.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm"
+			>
+			<File
+				RelativePath="..\..\minizip\miniunz.c"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;inc"
+			>
+		</Filter>
+		<Filter
+			Name="Resource Files"
+			Filter="rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+			>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/minizip.vcproj b/xs/src/png/zlib/contrib/vstudio/vc9/minizip.vcproj
new file mode 100644
index 000000000..ad4023991
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/minizip.vcproj
@@ -0,0 +1,562 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9.00"
+	Name="minizip"
+	ProjectGUID="{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}"
+	Keyword="Win32Proj"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+		<Platform
+			Name="x64"
+		/>
+		<Platform
+			Name="Itanium"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="x86\MiniZip$(ConfigurationName)"
+			IntermediateDirectory="x86\MiniZip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="1"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="4"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x86\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/minizip.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/minizip.pdb"
+				SubSystem="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="x86\MiniZip$(ConfigurationName)"
+			IntermediateDirectory="x86\MiniZip$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x86\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/minizip.exe"
+				LinkIncremental="1"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|x64"
+			OutputDirectory="x64\$(ConfigurationName)"
+			IntermediateDirectory="x64\$(ConfigurationName)"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x64\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/minizip.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/minizip.pdb"
+				SubSystem="1"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|Itanium"
+			OutputDirectory="ia64\$(ConfigurationName)"
+			IntermediateDirectory="ia64\$(ConfigurationName)"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="ia64\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/minizip.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/minizip.pdb"
+				SubSystem="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|x64"
+			OutputDirectory="x64\$(ConfigurationName)"
+			IntermediateDirectory="x64\$(ConfigurationName)"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x64\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/minizip.exe"
+				LinkIncremental="1"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Itanium"
+			OutputDirectory="ia64\$(ConfigurationName)"
+			IntermediateDirectory="ia64\$(ConfigurationName)"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="ia64\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/minizip.exe"
+				LinkIncremental="1"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm"
+			>
+			<File
+				RelativePath="..\..\minizip\minizip.c"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;inc"
+			>
+		</Filter>
+		<Filter
+			Name="Resource Files"
+			Filter="rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+			>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/testzlib.vcproj b/xs/src/png/zlib/contrib/vstudio/vc9/testzlib.vcproj
new file mode 100644
index 000000000..c9f19d24e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/testzlib.vcproj
@@ -0,0 +1,852 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9,00"
+	Name="testzlib"
+	ProjectGUID="{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}"
+	RootNamespace="testzlib"
+	Keyword="Win32Proj"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+		<Platform
+			Name="x64"
+		/>
+		<Platform
+			Name="Itanium"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="x86\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="x86\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ASMV;ASMINF;WIN32;ZLIB_WINAPI;_DEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="1"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerOutput="4"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="4"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="..\..\masmx86\match686.obj ..\..\masmx86\inffas32.obj"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/testzlib.pdb"
+				SubSystem="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|x64"
+			OutputDirectory="x64\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="x64\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ASMV;ASMINF;WIN32;ZLIB_WINAPI;_DEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				AssemblerListingLocation="$(IntDir)\"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="..\..\masmx64\gvmat64.obj ..\..\masmx64\inffasx64.obj"
+				GenerateManifest="false"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|Itanium"
+			OutputDirectory="ia64\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="ia64\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ZLIB_WINAPI;_DEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerOutput="4"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/testzlib.pdb"
+				SubSystem="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|Win32"
+			OutputDirectory="x86\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="x86\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			CharacterSet="2"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="WIN32;ZLIB_WINAPI;NDEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|x64"
+			OutputDirectory="x64\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="x64\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="WIN32;ZLIB_WINAPI;NDEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				AssemblerListingLocation="$(IntDir)\"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies=""
+				GenerateManifest="false"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|Itanium"
+			OutputDirectory="ia64\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="ia64\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			CharacterSet="2"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ZLIB_WINAPI;NDEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="x86\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="x86\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			CharacterSet="2"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ASMV;ASMINF;WIN32;ZLIB_WINAPI;NDEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="..\..\masmx86\match686.obj ..\..\masmx86\inffas32.obj"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|x64"
+			OutputDirectory="x64\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="x64\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ASMV;ASMINF;WIN32;ZLIB_WINAPI;NDEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				AssemblerListingLocation="$(IntDir)\"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="..\..\masmx64\gvmat64.obj ..\..\masmx64\inffasx64.obj"
+				GenerateManifest="false"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Itanium"
+			OutputDirectory="ia64\TestZlib$(ConfigurationName)"
+			IntermediateDirectory="ia64\TestZlib$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			CharacterSet="2"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\.."
+				PreprocessorDefinitions="ZLIB_WINAPI;NDEBUG;_CONSOLE;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm"
+			>
+			<File
+				RelativePath="..\..\..\adler32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\compress.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\crc32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\deflate.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\infback.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\masmx64\inffas8664.c"
+				>
+				<FileConfiguration
+					Name="Debug|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Debug|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="ReleaseWithoutAsm|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="ReleaseWithoutAsm|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+			</File>
+			<File
+				RelativePath="..\..\..\inffast.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inflate.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inftrees.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\testzlib\testzlib.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\trees.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\uncompr.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\zutil.c"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;inc"
+			>
+		</Filter>
+		<Filter
+			Name="Resource Files"
+			Filter="rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+			>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/testzlibdll.vcproj b/xs/src/png/zlib/contrib/vstudio/vc9/testzlibdll.vcproj
new file mode 100644
index 000000000..d7530fd7d
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/testzlibdll.vcproj
@@ -0,0 +1,565 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9.00"
+	Name="TestZlibDll"
+	ProjectGUID="{C52F9E7B-498A-42BE-8DB4-85A15694366A}"
+	Keyword="Win32Proj"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+		<Platform
+			Name="x64"
+		/>
+		<Platform
+			Name="Itanium"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="x86\TestZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x86\TestZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="1"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="4"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x86\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/testzlib.pdb"
+				SubSystem="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="x86\TestZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x86\TestZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x86\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|x64"
+			OutputDirectory="x64\TestZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x64\TestZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x64\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/testzlib.pdb"
+				SubSystem="1"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|Itanium"
+			OutputDirectory="ia64\TestZlibDll$(ConfigurationName)"
+			IntermediateDirectory="ia64\TestZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;_DEBUG;_CONSOLE;WIN64"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="ia64\ZlibDllDebug\zlibwapi.lib"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="2"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/testzlib.pdb"
+				SubSystem="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|x64"
+			OutputDirectory="x64\TestZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x64\TestZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="x64\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Itanium"
+			OutputDirectory="ia64\TestZlibDll$(ConfigurationName)"
+			IntermediateDirectory="ia64\TestZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="1"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			CharacterSet="2"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="2"
+				InlineFunctionExpansion="1"
+				OmitFramePointers="true"
+				AdditionalIncludeDirectories="..\..\..;..\..\minizip"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;ZLIB_WINAPI;NDEBUG;_CONSOLE;WIN64"
+				StringPooling="true"
+				BasicRuntimeChecks="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				UsePrecompiledHeader="0"
+				AssemblerListingLocation="$(IntDir)\"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="ia64\ZlibDllRelease\zlibwapi.lib"
+				OutputFile="$(OutDir)/testzlib.exe"
+				LinkIncremental="1"
+				GenerateManifest="false"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				OptimizeForWindows98="1"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cxx;def;odl;idl;hpj;bat;asm"
+			>
+			<File
+				RelativePath="..\..\testzlib\testzlib.c"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;inc"
+			>
+		</Filter>
+		<Filter
+			Name="Resource Files"
+			Filter="rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+			>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/zlib.rc b/xs/src/png/zlib/contrib/vstudio/vc9/zlib.rc
new file mode 100644
index 000000000..c4e4b016e
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/zlib.rc
@@ -0,0 +1,32 @@
+#include <windows.h>
+
+#define IDR_VERSION1  1
+IDR_VERSION1	VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+  FILEVERSION	 1, 2, 11, 0
+  PRODUCTVERSION 1, 2, 11, 0
+  FILEFLAGSMASK	VS_FFI_FILEFLAGSMASK
+  FILEFLAGS	0
+  FILEOS	VOS_DOS_WINDOWS32
+  FILETYPE	VFT_DLL
+  FILESUBTYPE	0	// not used
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+
+    BEGIN
+      VALUE "FileDescription", "zlib data compression and ZIP file I/O library\0"
+      VALUE "FileVersion",	"1.2.11\0"
+      VALUE "InternalName",	"zlib\0"
+      VALUE "OriginalFilename",	"zlibwapi.dll\0"
+      VALUE "ProductName",	"ZLib.DLL\0"
+      VALUE "Comments","DLL support by Alessandro Iacopetti & Gilles Vollant\0"
+      VALUE "LegalCopyright", "(C) 1995-2017 Jean-loup Gailly & Mark Adler\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/zlibstat.vcproj b/xs/src/png/zlib/contrib/vstudio/vc9/zlibstat.vcproj
new file mode 100644
index 000000000..d4ffb46b2
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/zlibstat.vcproj
@@ -0,0 +1,835 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9,00"
+	Name="zlibstat"
+	ProjectGUID="{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+		<Platform
+			Name="x64"
+		/>
+		<Platform
+			Name="Itanium"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="x86\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="x86\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				ExceptionHandling="0"
+				RuntimeLibrary="1"
+				BufferSecurityCheck="false"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="1"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:X86 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|x64"
+			OutputDirectory="x64\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="x64\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				ExceptionHandling="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="1"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:AMD64 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|Itanium"
+			OutputDirectory="ia64\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="ia64\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				ExceptionHandling="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="1"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:IA64 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="x86\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="x86\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ASMV;ASMINF"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:X86 /NODEFAULTLIB"
+				AdditionalDependencies="..\..\masmx86\match686.obj ..\..\masmx86\inffas32.obj "
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|x64"
+			OutputDirectory="x64\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="x64\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ASMV;ASMINF;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:AMD64 /NODEFAULTLIB"
+				AdditionalDependencies="..\..\masmx64\gvmat64.obj ..\..\masmx64\inffasx64.obj "
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Itanium"
+			OutputDirectory="ia64\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="ia64\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:IA64 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|Win32"
+			OutputDirectory="x86\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="x86\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:X86 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|x64"
+			OutputDirectory="x64\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="x64\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="3"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:AMD64 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|Itanium"
+			OutputDirectory="ia64\ZlibStat$(ConfigurationName)"
+			IntermediateDirectory="ia64\ZlibStat$(ConfigurationName)\Tmp"
+			ConfigurationType="4"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				TargetEnvironment="2"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="ZLIB_WINAPI;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibstat.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLibrarianTool"
+				AdditionalOptions="/MACHINE:IA64 /NODEFAULTLIB"
+				OutputFile="$(OutDir)\zlibstat.lib"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			>
+			<File
+				RelativePath="..\..\..\adler32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\compress.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\crc32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\deflate.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzclose.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzguts.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzlib.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzread.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzwrite.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\infback.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\masmx64\inffas8664.c"
+				>
+				<FileConfiguration
+					Name="Debug|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Debug|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="ReleaseWithoutAsm|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="ReleaseWithoutAsm|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+			</File>
+			<File
+				RelativePath="..\..\..\inffast.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inflate.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inftrees.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\minizip\ioapi.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\trees.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\uncompr.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\minizip\unzip.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\minizip\zip.c"
+				>
+			</File>
+			<File
+				RelativePath=".\zlib.rc"
+				>
+			</File>
+			<File
+				RelativePath=".\zlibvc.def"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\zutil.c"
+				>
+			</File>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.def b/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.def
new file mode 100644
index 000000000..f876c3bca
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.def
@@ -0,0 +1,153 @@
+LIBRARY
+; zlib data compression and ZIP file I/O library
+
+VERSION		1.2
+
+EXPORTS
+        adler32                                  @1
+        compress                                 @2
+        crc32                                    @3
+        deflate                                  @4
+        deflateCopy                              @5
+        deflateEnd                               @6
+        deflateInit2_                            @7
+        deflateInit_                             @8
+        deflateParams                            @9
+        deflateReset                             @10
+        deflateSetDictionary                     @11
+        gzclose                                  @12
+        gzdopen                                  @13
+        gzerror                                  @14
+        gzflush                                  @15
+        gzopen                                   @16
+        gzread                                   @17
+        gzwrite                                  @18
+        inflate                                  @19
+        inflateEnd                               @20
+        inflateInit2_                            @21
+        inflateInit_                             @22
+        inflateReset                             @23
+        inflateSetDictionary                     @24
+        inflateSync                              @25
+        uncompress                               @26
+        zlibVersion                              @27
+        gzprintf                                 @28
+        gzputc                                   @29
+        gzgetc                                   @30
+        gzseek                                   @31
+        gzrewind                                 @32
+        gztell                                   @33
+        gzeof                                    @34
+        gzsetparams                              @35
+        zError                                   @36
+        inflateSyncPoint                         @37
+        get_crc_table                            @38
+        compress2                                @39
+        gzputs                                   @40
+        gzgets                                   @41
+        inflateCopy                              @42
+        inflateBackInit_                         @43
+        inflateBack                              @44
+        inflateBackEnd                           @45
+        compressBound                            @46
+        deflateBound                             @47
+        gzclearerr                               @48
+        gzungetc                                 @49
+        zlibCompileFlags                         @50
+        deflatePrime                             @51
+        deflatePending                           @52
+
+        unzOpen                                  @61
+        unzClose                                 @62
+        unzGetGlobalInfo                         @63
+        unzGetCurrentFileInfo                    @64
+        unzGoToFirstFile                         @65
+        unzGoToNextFile                          @66
+        unzOpenCurrentFile                       @67
+        unzReadCurrentFile                       @68
+        unzOpenCurrentFile3                      @69
+        unztell                                  @70
+        unzeof                                   @71
+        unzCloseCurrentFile                      @72
+        unzGetGlobalComment                      @73
+        unzStringFileNameCompare                 @74
+        unzLocateFile                            @75
+        unzGetLocalExtrafield                    @76
+        unzOpen2                                 @77
+        unzOpenCurrentFile2                      @78
+        unzOpenCurrentFilePassword               @79
+
+        zipOpen                                  @80
+        zipOpenNewFileInZip                      @81
+        zipWriteInFileInZip                      @82
+        zipCloseFileInZip                        @83
+        zipClose                                 @84
+        zipOpenNewFileInZip2                     @86
+        zipCloseFileInZipRaw                     @87
+        zipOpen2                                 @88
+        zipOpenNewFileInZip3                     @89
+
+        unzGetFilePos                            @100
+        unzGoToFilePos                           @101
+
+        fill_win32_filefunc                      @110
+
+; zlibwapi v1.2.4 added:
+        fill_win32_filefunc64                   @111
+        fill_win32_filefunc64A                  @112
+        fill_win32_filefunc64W                  @113
+
+        unzOpen64                               @120
+        unzOpen2_64                             @121
+        unzGetGlobalInfo64                      @122
+        unzGetCurrentFileInfo64                 @124
+        unzGetCurrentFileZStreamPos64           @125
+        unztell64                               @126
+        unzGetFilePos64                         @127
+        unzGoToFilePos64                        @128
+
+        zipOpen64                               @130
+        zipOpen2_64                             @131
+        zipOpenNewFileInZip64                   @132
+        zipOpenNewFileInZip2_64                 @133
+        zipOpenNewFileInZip3_64                 @134
+        zipOpenNewFileInZip4_64                 @135
+        zipCloseFileInZipRaw64                  @136
+
+; zlib1 v1.2.4 added:
+        adler32_combine                         @140
+        crc32_combine                           @142
+        deflateSetHeader                        @144
+        deflateTune                             @145
+        gzbuffer                                @146
+        gzclose_r                               @147
+        gzclose_w                               @148
+        gzdirect                                @149
+        gzoffset                                @150
+        inflateGetHeader                        @156
+        inflateMark                             @157
+        inflatePrime                            @158
+        inflateReset2                           @159
+        inflateUndermine                        @160
+
+; zlib1 v1.2.6 added:
+        gzgetc_                                 @161
+        inflateResetKeep                        @163
+        deflateResetKeep                        @164
+
+; zlib1 v1.2.7 added:
+        gzopen_w                                @165
+
+; zlib1 v1.2.8 added:
+        inflateGetDictionary                    @166
+        gzvprintf                               @167
+
+; zlib1 v1.2.9 added:
+        inflateCodesUsed                        @168
+        inflateValidate                         @169
+        uncompress2                             @170
+        gzfread                                 @171
+        gzfwrite                                @172
+        deflateGetDictionary                    @173
+        adler32_z                               @174
+        crc32_z                                 @175
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.sln b/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.sln
new file mode 100644
index 000000000..75c64c3f4
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.sln
@@ -0,0 +1,144 @@
+
+Microsoft Visual Studio Solution File, Format Version 10.00
+# Visual Studio 2008
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibvc", "zlibvc.vcproj", "{8FD826F8-3739-44E6-8CC8-997122E53B8D}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlibstat", "zlibstat.vcproj", "{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "testzlib", "testzlib.vcproj", "{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}"
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "TestZlibDll", "testzlibdll.vcproj", "{C52F9E7B-498A-42BE-8DB4-85A15694366A}"
+	ProjectSection(ProjectDependencies) = postProject
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D} = {8FD826F8-3739-44E6-8CC8-997122E53B8D}
+	EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "minizip", "minizip.vcproj", "{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}"
+	ProjectSection(ProjectDependencies) = postProject
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D} = {8FD826F8-3739-44E6-8CC8-997122E53B8D}
+	EndProjectSection
+EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "miniunz", "miniunz.vcproj", "{C52F9E7B-498A-42BE-8DB4-85A15694382A}"
+	ProjectSection(ProjectDependencies) = postProject
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D} = {8FD826F8-3739-44E6-8CC8-997122E53B8D}
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Itanium = Debug|Itanium
+		Debug|Win32 = Debug|Win32
+		Debug|x64 = Debug|x64
+		Release|Itanium = Release|Itanium
+		Release|Win32 = Release|Win32
+		Release|x64 = Release|x64
+		ReleaseWithoutAsm|Itanium = ReleaseWithoutAsm|Itanium
+		ReleaseWithoutAsm|Win32 = ReleaseWithoutAsm|Win32
+		ReleaseWithoutAsm|x64 = ReleaseWithoutAsm|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Itanium.Build.0 = Debug|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.ActiveCfg = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|Win32.Build.0 = Debug|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.ActiveCfg = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Debug|x64.Build.0 = Debug|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Itanium.ActiveCfg = Release|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Itanium.Build.0 = Release|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.ActiveCfg = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|Win32.Build.0 = Release|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.ActiveCfg = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.Release|x64.Build.0 = Release|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Itanium.Build.0 = ReleaseWithoutAsm|Itanium
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{8FD826F8-3739-44E6-8CC8-997122E53B8D}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Itanium.Build.0 = Debug|Itanium
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.ActiveCfg = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|Win32.Build.0 = Debug|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.ActiveCfg = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Debug|x64.Build.0 = Debug|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Itanium.ActiveCfg = Release|Itanium
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Itanium.Build.0 = Release|Itanium
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.ActiveCfg = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|Win32.Build.0 = Release|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|x64.ActiveCfg = Release|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.Release|x64.Build.0 = Release|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Itanium
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Itanium.Build.0 = ReleaseWithoutAsm|Itanium
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{745DEC58-EBB3-47A9-A9B8-4C6627C01BF8}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.Build.0 = Debug|Itanium
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.ActiveCfg = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.Build.0 = Debug|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.ActiveCfg = Debug|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.Build.0 = Debug|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.ActiveCfg = Release|Itanium
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.Build.0 = Release|Itanium
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.ActiveCfg = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.Build.0 = Release|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.ActiveCfg = Release|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.Build.0 = Release|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.ActiveCfg = ReleaseWithoutAsm|Itanium
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.Build.0 = ReleaseWithoutAsm|Itanium
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.ActiveCfg = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.Build.0 = ReleaseWithoutAsm|Win32
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.ActiveCfg = ReleaseWithoutAsm|x64
+		{AA6666AA-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.Build.0 = ReleaseWithoutAsm|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Itanium.Build.0 = Debug|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|Win32.Build.0 = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|x64.ActiveCfg = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Debug|x64.Build.0 = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Itanium.ActiveCfg = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Itanium.Build.0 = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|Win32.Build.0 = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.Release|x64.Build.0 = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Itanium.Build.0 = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694366A}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Itanium.Build.0 = Debug|Itanium
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.ActiveCfg = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|Win32.Build.0 = Debug|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.ActiveCfg = Debug|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Debug|x64.Build.0 = Debug|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.ActiveCfg = Release|Itanium
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Itanium.Build.0 = Release|Itanium
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|Win32.Build.0 = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.ActiveCfg = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.Release|x64.Build.0 = Release|x64
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Itanium
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Itanium.Build.0 = Release|Itanium
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{48CDD9DC-E09F-4135-9C0C-4FE50C3C654B}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Itanium.ActiveCfg = Debug|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Itanium.Build.0 = Debug|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|Win32.Build.0 = Debug|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|x64.ActiveCfg = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Debug|x64.Build.0 = Debug|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Itanium.ActiveCfg = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Itanium.Build.0 = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|Win32.Build.0 = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|x64.ActiveCfg = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.Release|x64.Build.0 = Release|x64
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|Itanium.ActiveCfg = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|Itanium.Build.0 = Release|Itanium
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|Win32.ActiveCfg = Release|Win32
+		{C52F9E7B-498A-42BE-8DB4-85A15694382A}.ReleaseWithoutAsm|x64.ActiveCfg = Release|x64
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
diff --git a/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.vcproj b/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.vcproj
new file mode 100644
index 000000000..95bb241f3
--- /dev/null
+++ b/xs/src/png/zlib/contrib/vstudio/vc9/zlibvc.vcproj
@@ -0,0 +1,1156 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="9,00"
+	Name="zlibvc"
+	ProjectGUID="{8FD826F8-3739-44E6-8CC8-997122E53B8D}"
+	RootNamespace="zlibvc"
+	TargetFrameworkVersion="131072"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+		<Platform
+			Name="x64"
+		/>
+		<Platform
+			Name="Itanium"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="x86\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x86\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="_DEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="1"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;ASMV;ASMINF"
+				ExceptionHandling="0"
+				RuntimeLibrary="1"
+				BufferSecurityCheck="false"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+				DebugInformationFormat="4"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="_DEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalOptions="/MACHINE:I386"
+				AdditionalDependencies="..\..\masmx86\match686.obj ..\..\masmx86\inffas32.obj"
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="2"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|x64"
+			OutputDirectory="x64\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x64\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="_DEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="3"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;ASMV;ASMINF;WIN64"
+				ExceptionHandling="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="_DEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="..\..\masmx64\gvmat64.obj ..\..\masmx64\inffasx64.obj "
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="2"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Debug|Itanium"
+			OutputDirectory="ia64\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="ia64\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="_DEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="2"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;WIN64"
+				ExceptionHandling="0"
+				RuntimeLibrary="3"
+				BufferSecurityCheck="false"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="_DEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="2"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				GenerateDebugInformation="true"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|Win32"
+			OutputDirectory="x86\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x86\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="NDEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="1"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerOutput="2"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="NDEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalOptions="/MACHINE:I386"
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="1"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				IgnoreAllDefaultLibraries="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|x64"
+			OutputDirectory="x64\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x64\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="NDEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="3"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerOutput="2"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="NDEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="1"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				IgnoreAllDefaultLibraries="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				OptimizeForWindows98="1"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="ReleaseWithoutAsm|Itanium"
+			OutputDirectory="ia64\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="ia64\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="NDEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="2"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerOutput="2"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="NDEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="1"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				IgnoreAllDefaultLibraries="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				OptimizeForWindows98="1"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="x86\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x86\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="NDEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="1"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="WIN32;_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;ASMV;ASMINF"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="0"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerOutput="2"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="NDEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalOptions="/MACHINE:I386"
+				AdditionalDependencies="..\..\masmx86\match686.obj ..\..\masmx86\inffas32.obj "
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="1"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				IgnoreAllDefaultLibraries="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				OptimizeForWindows98="1"
+				RandomizedBaseAddress="1"
+				DataExecutionPrevention="0"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|x64"
+			OutputDirectory="x64\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="x64\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="NDEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="3"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;ASMV;ASMINF;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerOutput="2"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="NDEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				AdditionalDependencies="..\..\masmx64\gvmat64.obj ..\..\masmx64\inffasx64.obj "
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="1"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				IgnoreAllDefaultLibraries="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				OptimizeForWindows98="1"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+				TargetMachine="17"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Itanium"
+			OutputDirectory="ia64\ZlibDll$(ConfigurationName)"
+			IntermediateDirectory="ia64\ZlibDll$(ConfigurationName)\Tmp"
+			ConfigurationType="2"
+			InheritedPropertySheets="UpgradeFromVC70.vsprops"
+			UseOfMFC="0"
+			ATLMinimizesCRunTimeLibraryUsage="false"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+				PreprocessorDefinitions="NDEBUG"
+				MkTypLibCompatible="true"
+				SuppressStartupBanner="true"
+				TargetEnvironment="2"
+				TypeLibraryName="$(OutDir)/zlibvc.tlb"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				InlineFunctionExpansion="1"
+				AdditionalIncludeDirectories="..\..\..;..\..\masmx86"
+				PreprocessorDefinitions="_CRT_NONSTDC_NO_DEPRECATE;_CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;ZLIB_WINAPI;WIN64"
+				StringPooling="true"
+				ExceptionHandling="0"
+				RuntimeLibrary="2"
+				BufferSecurityCheck="false"
+				EnableFunctionLevelLinking="true"
+				PrecompiledHeaderFile="$(IntDir)/zlibvc.pch"
+				AssemblerOutput="2"
+				AssemblerListingLocation="$(IntDir)\"
+				ObjectFile="$(IntDir)\"
+				ProgramDataBaseFileName="$(OutDir)\"
+				BrowseInformation="0"
+				WarningLevel="3"
+				SuppressStartupBanner="true"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+				PreprocessorDefinitions="NDEBUG"
+				Culture="1036"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				OutputFile="$(OutDir)\zlibwapi.dll"
+				LinkIncremental="1"
+				SuppressStartupBanner="true"
+				GenerateManifest="false"
+				IgnoreAllDefaultLibraries="false"
+				ModuleDefinitionFile=".\zlibvc.def"
+				ProgramDatabaseFile="$(OutDir)/zlibwapi.pdb"
+				GenerateMapFile="true"
+				MapFileName="$(OutDir)/zlibwapi.map"
+				SubSystem="2"
+				OptimizeForWindows98="1"
+				ImportLibrary="$(OutDir)/zlibwapi.lib"
+				TargetMachine="5"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cxx;rc;def;r;odl;hpj;bat;for;f90"
+			>
+			<File
+				RelativePath="..\..\..\adler32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\compress.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\crc32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\deflate.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzclose.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzguts.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzlib.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzread.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\gzwrite.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\infback.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\masmx64\inffas8664.c"
+				>
+				<FileConfiguration
+					Name="Debug|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Debug|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="ReleaseWithoutAsm|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="ReleaseWithoutAsm|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Win32"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Itanium"
+					ExcludedFromBuild="true"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+					/>
+				</FileConfiguration>
+			</File>
+			<File
+				RelativePath="..\..\..\inffast.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inflate.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inftrees.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\minizip\ioapi.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\minizip\iowin32.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\trees.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\uncompr.c"
+				>
+			</File>
+			<File
+				RelativePath="..\..\minizip\unzip.c"
+				>
+				<FileConfiguration
+					Name="Release|Win32"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+						AdditionalIncludeDirectories=""
+						PreprocessorDefinitions="ZLIB_INTERNAL"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|x64"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+						AdditionalIncludeDirectories=""
+						PreprocessorDefinitions="ZLIB_INTERNAL"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Itanium"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+						AdditionalIncludeDirectories=""
+						PreprocessorDefinitions="ZLIB_INTERNAL"
+					/>
+				</FileConfiguration>
+			</File>
+			<File
+				RelativePath="..\..\minizip\zip.c"
+				>
+				<FileConfiguration
+					Name="Release|Win32"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+						AdditionalIncludeDirectories=""
+						PreprocessorDefinitions="ZLIB_INTERNAL"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|x64"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+						AdditionalIncludeDirectories=""
+						PreprocessorDefinitions="ZLIB_INTERNAL"
+					/>
+				</FileConfiguration>
+				<FileConfiguration
+					Name="Release|Itanium"
+					>
+					<Tool
+						Name="VCCLCompilerTool"
+						AdditionalIncludeDirectories=""
+						PreprocessorDefinitions="ZLIB_INTERNAL"
+					/>
+				</FileConfiguration>
+			</File>
+			<File
+				RelativePath=".\zlib.rc"
+				>
+			</File>
+			<File
+				RelativePath=".\zlibvc.def"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\zutil.c"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;fi;fd"
+			>
+			<File
+				RelativePath="..\..\..\deflate.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\infblock.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\infcodes.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inffast.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\inftrees.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\infutil.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\zconf.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\zlib.h"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\zutil.h"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Resource Files"
+			Filter="ico;cur;bmp;dlg;rc2;rct;bin;cnt;rtf;gif;jpg;jpeg;jpe"
+			>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>
diff --git a/xs/src/png/zlib/crc32.c b/xs/src/png/zlib/crc32.c
new file mode 100644
index 000000000..9580440c0
--- /dev/null
+++ b/xs/src/png/zlib/crc32.c
@@ -0,0 +1,442 @@
+/* crc32.c -- compute the CRC-32 of a data stream
+ * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster
+ * CRC methods: exclusive-oring 32 bits of data at a time, and pre-computing
+ * tables for updating the shift register in one step with three exclusive-ors
+ * instead of four steps with four exclusive-ors.  This results in about a
+ * factor of two increase in speed on a Power PC G4 (PPC7455) using gcc -O3.
+ */
+
+/* @(#) $Id$ */
+
+/*
+  Note on the use of DYNAMIC_CRC_TABLE: there is no mutex or semaphore
+  protection on the static variables used to control the first-use generation
+  of the crc tables.  Therefore, if you #define DYNAMIC_CRC_TABLE, you should
+  first call get_crc_table() to initialize the tables before allowing more than
+  one thread to use crc32().
+
+  DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32.h.
+ */
+
+#ifdef MAKECRCH
+#  include <stdio.h>
+#  ifndef DYNAMIC_CRC_TABLE
+#    define DYNAMIC_CRC_TABLE
+#  endif /* !DYNAMIC_CRC_TABLE */
+#endif /* MAKECRCH */
+
+#include "zutil.h"      /* for STDC and FAR definitions */
+
+/* Definitions for doing the crc four data bytes at a time. */
+#if !defined(NOBYFOUR) && defined(Z_U4)
+#  define BYFOUR
+#endif
+#ifdef BYFOUR
+   local unsigned long crc32_little OF((unsigned long,
+                        const unsigned char FAR *, z_size_t));
+   local unsigned long crc32_big OF((unsigned long,
+                        const unsigned char FAR *, z_size_t));
+#  define TBLS 8
+#else
+#  define TBLS 1
+#endif /* BYFOUR */
+
+/* Local functions for crc concatenation */
+local unsigned long gf2_matrix_times OF((unsigned long *mat,
+                                         unsigned long vec));
+local void gf2_matrix_square OF((unsigned long *square, unsigned long *mat));
+local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2));
+
+
+#ifdef DYNAMIC_CRC_TABLE
+
+local volatile int crc_table_empty = 1;
+local z_crc_t FAR crc_table[TBLS][256];
+local void make_crc_table OF((void));
+#ifdef MAKECRCH
+   local void write_table OF((FILE *, const z_crc_t FAR *));
+#endif /* MAKECRCH */
+/*
+  Generate tables for a byte-wise 32-bit CRC calculation on the polynomial:
+  x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
+
+  Polynomials over GF(2) are represented in binary, one bit per coefficient,
+  with the lowest powers in the most significant bit.  Then adding polynomials
+  is just exclusive-or, and multiplying a polynomial by x is a right shift by
+  one.  If we call the above polynomial p, and represent a byte as the
+  polynomial q, also with the lowest power in the most significant bit (so the
+  byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
+  where a mod b means the remainder after dividing a by b.
+
+  This calculation is done using the shift-register method of multiplying and
+  taking the remainder.  The register is initialized to zero, and for each
+  incoming bit, x^32 is added mod p to the register if the bit is a one (where
+  x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
+  x (which is shifting right by one and adding x^32 mod p if the bit shifted
+  out is a one).  We start with the highest power (least significant bit) of
+  q and repeat for all eight bits of q.
+
+  The first table is simply the CRC of all possible eight bit values.  This is
+  all the information needed to generate CRCs on data a byte at a time for all
+  combinations of CRC register values and incoming bytes.  The remaining tables
+  allow for word-at-a-time CRC calculation for both big-endian and little-
+  endian machines, where a word is four bytes.
+*/
+local void make_crc_table()
+{
+    z_crc_t c;
+    int n, k;
+    z_crc_t poly;                       /* polynomial exclusive-or pattern */
+    /* terms of polynomial defining this crc (except x^32): */
+    static volatile int first = 1;      /* flag to limit concurrent making */
+    static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
+
+    /* See if another task is already doing this (not thread-safe, but better
+       than nothing -- significantly reduces duration of vulnerability in
+       case the advice about DYNAMIC_CRC_TABLE is ignored) */
+    if (first) {
+        first = 0;
+
+        /* make exclusive-or pattern from polynomial (0xedb88320UL) */
+        poly = 0;
+        for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++)
+            poly |= (z_crc_t)1 << (31 - p[n]);
+
+        /* generate a crc for every 8-bit value */
+        for (n = 0; n < 256; n++) {
+            c = (z_crc_t)n;
+            for (k = 0; k < 8; k++)
+                c = c & 1 ? poly ^ (c >> 1) : c >> 1;
+            crc_table[0][n] = c;
+        }
+
+#ifdef BYFOUR
+        /* generate crc for each value followed by one, two, and three zeros,
+           and then the byte reversal of those as well as the first table */
+        for (n = 0; n < 256; n++) {
+            c = crc_table[0][n];
+            crc_table[4][n] = ZSWAP32(c);
+            for (k = 1; k < 4; k++) {
+                c = crc_table[0][c & 0xff] ^ (c >> 8);
+                crc_table[k][n] = c;
+                crc_table[k + 4][n] = ZSWAP32(c);
+            }
+        }
+#endif /* BYFOUR */
+
+        crc_table_empty = 0;
+    }
+    else {      /* not first */
+        /* wait for the other guy to finish (not efficient, but rare) */
+        while (crc_table_empty)
+            ;
+    }
+
+#ifdef MAKECRCH
+    /* write out CRC tables to crc32.h */
+    {
+        FILE *out;
+
+        out = fopen("crc32.h", "w");
+        if (out == NULL) return;
+        fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n");
+        fprintf(out, " * Generated automatically by crc32.c\n */\n\n");
+        fprintf(out, "local const z_crc_t FAR ");
+        fprintf(out, "crc_table[TBLS][256] =\n{\n  {\n");
+        write_table(out, crc_table[0]);
+#  ifdef BYFOUR
+        fprintf(out, "#ifdef BYFOUR\n");
+        for (k = 1; k < 8; k++) {
+            fprintf(out, "  },\n  {\n");
+            write_table(out, crc_table[k]);
+        }
+        fprintf(out, "#endif\n");
+#  endif /* BYFOUR */
+        fprintf(out, "  }\n};\n");
+        fclose(out);
+    }
+#endif /* MAKECRCH */
+}
+
+#ifdef MAKECRCH
+local void write_table(out, table)
+    FILE *out;
+    const z_crc_t FAR *table;
+{
+    int n;
+
+    for (n = 0; n < 256; n++)
+        fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : "    ",
+                (unsigned long)(table[n]),
+                n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", "));
+}
+#endif /* MAKECRCH */
+
+#else /* !DYNAMIC_CRC_TABLE */
+/* ========================================================================
+ * Tables of CRC-32s of all single-byte values, made by make_crc_table().
+ */
+#include "crc32.h"
+#endif /* DYNAMIC_CRC_TABLE */
+
+/* =========================================================================
+ * This function can be used by asm versions of crc32()
+ */
+const z_crc_t FAR * ZEXPORT get_crc_table()
+{
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+    return (const z_crc_t FAR *)crc_table;
+}
+
+/* ========================================================================= */
+#define DO1 crc = crc_table[0][((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8)
+#define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1
+
+/* ========================================================================= */
+unsigned long ZEXPORT crc32_z(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    if (buf == Z_NULL) return 0UL;
+
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+
+#ifdef BYFOUR
+    if (sizeof(void *) == sizeof(ptrdiff_t)) {
+        z_crc_t endian;
+
+        endian = 1;
+        if (*((unsigned char *)(&endian)))
+            return crc32_little(crc, buf, len);
+        else
+            return crc32_big(crc, buf, len);
+    }
+#endif /* BYFOUR */
+    crc = crc ^ 0xffffffffUL;
+    while (len >= 8) {
+        DO8;
+        len -= 8;
+    }
+    if (len) do {
+        DO1;
+    } while (--len);
+    return crc ^ 0xffffffffUL;
+}
+
+/* ========================================================================= */
+unsigned long ZEXPORT crc32(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    uInt len;
+{
+    return crc32_z(crc, buf, len);
+}
+
+#ifdef BYFOUR
+
+/*
+   This BYFOUR code accesses the passed unsigned char * buffer with a 32-bit
+   integer pointer type. This violates the strict aliasing rule, where a
+   compiler can assume, for optimization purposes, that two pointers to
+   fundamentally different types won't ever point to the same memory. This can
+   manifest as a problem only if one of the pointers is written to. This code
+   only reads from those pointers. So long as this code remains isolated in
+   this compilation unit, there won't be a problem. For this reason, this code
+   should not be copied and pasted into a compilation unit in which other code
+   writes to the buffer that is passed to these routines.
+ */
+
+/* ========================================================================= */
+#define DOLIT4 c ^= *buf4++; \
+        c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \
+            crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24]
+#define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4
+
+/* ========================================================================= */
+local unsigned long crc32_little(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    register z_crc_t c;
+    register const z_crc_t FAR *buf4;
+
+    c = (z_crc_t)crc;
+    c = ~c;
+    while (len && ((ptrdiff_t)buf & 3)) {
+        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
+        len--;
+    }
+
+    buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
+    while (len >= 32) {
+        DOLIT32;
+        len -= 32;
+    }
+    while (len >= 4) {
+        DOLIT4;
+        len -= 4;
+    }
+    buf = (const unsigned char FAR *)buf4;
+
+    if (len) do {
+        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
+    } while (--len);
+    c = ~c;
+    return (unsigned long)c;
+}
+
+/* ========================================================================= */
+#define DOBIG4 c ^= *buf4++; \
+        c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \
+            crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24]
+#define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4
+
+/* ========================================================================= */
+local unsigned long crc32_big(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    register z_crc_t c;
+    register const z_crc_t FAR *buf4;
+
+    c = ZSWAP32((z_crc_t)crc);
+    c = ~c;
+    while (len && ((ptrdiff_t)buf & 3)) {
+        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
+        len--;
+    }
+
+    buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
+    while (len >= 32) {
+        DOBIG32;
+        len -= 32;
+    }
+    while (len >= 4) {
+        DOBIG4;
+        len -= 4;
+    }
+    buf = (const unsigned char FAR *)buf4;
+
+    if (len) do {
+        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
+    } while (--len);
+    c = ~c;
+    return (unsigned long)(ZSWAP32(c));
+}
+
+#endif /* BYFOUR */
+
+#define GF2_DIM 32      /* dimension of GF(2) vectors (length of CRC) */
+
+/* ========================================================================= */
+local unsigned long gf2_matrix_times(mat, vec)
+    unsigned long *mat;
+    unsigned long vec;
+{
+    unsigned long sum;
+
+    sum = 0;
+    while (vec) {
+        if (vec & 1)
+            sum ^= *mat;
+        vec >>= 1;
+        mat++;
+    }
+    return sum;
+}
+
+/* ========================================================================= */
+local void gf2_matrix_square(square, mat)
+    unsigned long *square;
+    unsigned long *mat;
+{
+    int n;
+
+    for (n = 0; n < GF2_DIM; n++)
+        square[n] = gf2_matrix_times(mat, mat[n]);
+}
+
+/* ========================================================================= */
+local uLong crc32_combine_(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off64_t len2;
+{
+    int n;
+    unsigned long row;
+    unsigned long even[GF2_DIM];    /* even-power-of-two zeros operator */
+    unsigned long odd[GF2_DIM];     /* odd-power-of-two zeros operator */
+
+    /* degenerate case (also disallow negative lengths) */
+    if (len2 <= 0)
+        return crc1;
+
+    /* put operator for one zero bit in odd */
+    odd[0] = 0xedb88320UL;          /* CRC-32 polynomial */
+    row = 1;
+    for (n = 1; n < GF2_DIM; n++) {
+        odd[n] = row;
+        row <<= 1;
+    }
+
+    /* put operator for two zero bits in even */
+    gf2_matrix_square(even, odd);
+
+    /* put operator for four zero bits in odd */
+    gf2_matrix_square(odd, even);
+
+    /* apply len2 zeros to crc1 (first square will put the operator for one
+       zero byte, eight zero bits, in even) */
+    do {
+        /* apply zeros operator for this bit of len2 */
+        gf2_matrix_square(even, odd);
+        if (len2 & 1)
+            crc1 = gf2_matrix_times(even, crc1);
+        len2 >>= 1;
+
+        /* if no more bits set, then done */
+        if (len2 == 0)
+            break;
+
+        /* another iteration of the loop with odd and even swapped */
+        gf2_matrix_square(odd, even);
+        if (len2 & 1)
+            crc1 = gf2_matrix_times(odd, crc1);
+        len2 >>= 1;
+
+        /* if no more bits set, then done */
+    } while (len2 != 0);
+
+    /* return combined crc */
+    crc1 ^= crc2;
+    return crc1;
+}
+
+/* ========================================================================= */
+uLong ZEXPORT crc32_combine(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off_t len2;
+{
+    return crc32_combine_(crc1, crc2, len2);
+}
+
+uLong ZEXPORT crc32_combine64(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off64_t len2;
+{
+    return crc32_combine_(crc1, crc2, len2);
+}
diff --git a/xs/src/png/zlib/crc32.h b/xs/src/png/zlib/crc32.h
new file mode 100644
index 000000000..9e0c77810
--- /dev/null
+++ b/xs/src/png/zlib/crc32.h
@@ -0,0 +1,441 @@
+/* crc32.h -- tables for rapid CRC calculation
+ * Generated automatically by crc32.c
+ */
+
+local const z_crc_t FAR crc_table[TBLS][256] =
+{
+  {
+    0x00000000UL, 0x77073096UL, 0xee0e612cUL, 0x990951baUL, 0x076dc419UL,
+    0x706af48fUL, 0xe963a535UL, 0x9e6495a3UL, 0x0edb8832UL, 0x79dcb8a4UL,
+    0xe0d5e91eUL, 0x97d2d988UL, 0x09b64c2bUL, 0x7eb17cbdUL, 0xe7b82d07UL,
+    0x90bf1d91UL, 0x1db71064UL, 0x6ab020f2UL, 0xf3b97148UL, 0x84be41deUL,
+    0x1adad47dUL, 0x6ddde4ebUL, 0xf4d4b551UL, 0x83d385c7UL, 0x136c9856UL,
+    0x646ba8c0UL, 0xfd62f97aUL, 0x8a65c9ecUL, 0x14015c4fUL, 0x63066cd9UL,
+    0xfa0f3d63UL, 0x8d080df5UL, 0x3b6e20c8UL, 0x4c69105eUL, 0xd56041e4UL,
+    0xa2677172UL, 0x3c03e4d1UL, 0x4b04d447UL, 0xd20d85fdUL, 0xa50ab56bUL,
+    0x35b5a8faUL, 0x42b2986cUL, 0xdbbbc9d6UL, 0xacbcf940UL, 0x32d86ce3UL,
+    0x45df5c75UL, 0xdcd60dcfUL, 0xabd13d59UL, 0x26d930acUL, 0x51de003aUL,
+    0xc8d75180UL, 0xbfd06116UL, 0x21b4f4b5UL, 0x56b3c423UL, 0xcfba9599UL,
+    0xb8bda50fUL, 0x2802b89eUL, 0x5f058808UL, 0xc60cd9b2UL, 0xb10be924UL,
+    0x2f6f7c87UL, 0x58684c11UL, 0xc1611dabUL, 0xb6662d3dUL, 0x76dc4190UL,
+    0x01db7106UL, 0x98d220bcUL, 0xefd5102aUL, 0x71b18589UL, 0x06b6b51fUL,
+    0x9fbfe4a5UL, 0xe8b8d433UL, 0x7807c9a2UL, 0x0f00f934UL, 0x9609a88eUL,
+    0xe10e9818UL, 0x7f6a0dbbUL, 0x086d3d2dUL, 0x91646c97UL, 0xe6635c01UL,
+    0x6b6b51f4UL, 0x1c6c6162UL, 0x856530d8UL, 0xf262004eUL, 0x6c0695edUL,
+    0x1b01a57bUL, 0x8208f4c1UL, 0xf50fc457UL, 0x65b0d9c6UL, 0x12b7e950UL,
+    0x8bbeb8eaUL, 0xfcb9887cUL, 0x62dd1ddfUL, 0x15da2d49UL, 0x8cd37cf3UL,
+    0xfbd44c65UL, 0x4db26158UL, 0x3ab551ceUL, 0xa3bc0074UL, 0xd4bb30e2UL,
+    0x4adfa541UL, 0x3dd895d7UL, 0xa4d1c46dUL, 0xd3d6f4fbUL, 0x4369e96aUL,
+    0x346ed9fcUL, 0xad678846UL, 0xda60b8d0UL, 0x44042d73UL, 0x33031de5UL,
+    0xaa0a4c5fUL, 0xdd0d7cc9UL, 0x5005713cUL, 0x270241aaUL, 0xbe0b1010UL,
+    0xc90c2086UL, 0x5768b525UL, 0x206f85b3UL, 0xb966d409UL, 0xce61e49fUL,
+    0x5edef90eUL, 0x29d9c998UL, 0xb0d09822UL, 0xc7d7a8b4UL, 0x59b33d17UL,
+    0x2eb40d81UL, 0xb7bd5c3bUL, 0xc0ba6cadUL, 0xedb88320UL, 0x9abfb3b6UL,
+    0x03b6e20cUL, 0x74b1d29aUL, 0xead54739UL, 0x9dd277afUL, 0x04db2615UL,
+    0x73dc1683UL, 0xe3630b12UL, 0x94643b84UL, 0x0d6d6a3eUL, 0x7a6a5aa8UL,
+    0xe40ecf0bUL, 0x9309ff9dUL, 0x0a00ae27UL, 0x7d079eb1UL, 0xf00f9344UL,
+    0x8708a3d2UL, 0x1e01f268UL, 0x6906c2feUL, 0xf762575dUL, 0x806567cbUL,
+    0x196c3671UL, 0x6e6b06e7UL, 0xfed41b76UL, 0x89d32be0UL, 0x10da7a5aUL,
+    0x67dd4accUL, 0xf9b9df6fUL, 0x8ebeeff9UL, 0x17b7be43UL, 0x60b08ed5UL,
+    0xd6d6a3e8UL, 0xa1d1937eUL, 0x38d8c2c4UL, 0x4fdff252UL, 0xd1bb67f1UL,
+    0xa6bc5767UL, 0x3fb506ddUL, 0x48b2364bUL, 0xd80d2bdaUL, 0xaf0a1b4cUL,
+    0x36034af6UL, 0x41047a60UL, 0xdf60efc3UL, 0xa867df55UL, 0x316e8eefUL,
+    0x4669be79UL, 0xcb61b38cUL, 0xbc66831aUL, 0x256fd2a0UL, 0x5268e236UL,
+    0xcc0c7795UL, 0xbb0b4703UL, 0x220216b9UL, 0x5505262fUL, 0xc5ba3bbeUL,
+    0xb2bd0b28UL, 0x2bb45a92UL, 0x5cb36a04UL, 0xc2d7ffa7UL, 0xb5d0cf31UL,
+    0x2cd99e8bUL, 0x5bdeae1dUL, 0x9b64c2b0UL, 0xec63f226UL, 0x756aa39cUL,
+    0x026d930aUL, 0x9c0906a9UL, 0xeb0e363fUL, 0x72076785UL, 0x05005713UL,
+    0x95bf4a82UL, 0xe2b87a14UL, 0x7bb12baeUL, 0x0cb61b38UL, 0x92d28e9bUL,
+    0xe5d5be0dUL, 0x7cdcefb7UL, 0x0bdbdf21UL, 0x86d3d2d4UL, 0xf1d4e242UL,
+    0x68ddb3f8UL, 0x1fda836eUL, 0x81be16cdUL, 0xf6b9265bUL, 0x6fb077e1UL,
+    0x18b74777UL, 0x88085ae6UL, 0xff0f6a70UL, 0x66063bcaUL, 0x11010b5cUL,
+    0x8f659effUL, 0xf862ae69UL, 0x616bffd3UL, 0x166ccf45UL, 0xa00ae278UL,
+    0xd70dd2eeUL, 0x4e048354UL, 0x3903b3c2UL, 0xa7672661UL, 0xd06016f7UL,
+    0x4969474dUL, 0x3e6e77dbUL, 0xaed16a4aUL, 0xd9d65adcUL, 0x40df0b66UL,
+    0x37d83bf0UL, 0xa9bcae53UL, 0xdebb9ec5UL, 0x47b2cf7fUL, 0x30b5ffe9UL,
+    0xbdbdf21cUL, 0xcabac28aUL, 0x53b39330UL, 0x24b4a3a6UL, 0xbad03605UL,
+    0xcdd70693UL, 0x54de5729UL, 0x23d967bfUL, 0xb3667a2eUL, 0xc4614ab8UL,
+    0x5d681b02UL, 0x2a6f2b94UL, 0xb40bbe37UL, 0xc30c8ea1UL, 0x5a05df1bUL,
+    0x2d02ef8dUL
+#ifdef BYFOUR
+  },
+  {
+    0x00000000UL, 0x191b3141UL, 0x32366282UL, 0x2b2d53c3UL, 0x646cc504UL,
+    0x7d77f445UL, 0x565aa786UL, 0x4f4196c7UL, 0xc8d98a08UL, 0xd1c2bb49UL,
+    0xfaefe88aUL, 0xe3f4d9cbUL, 0xacb54f0cUL, 0xb5ae7e4dUL, 0x9e832d8eUL,
+    0x87981ccfUL, 0x4ac21251UL, 0x53d92310UL, 0x78f470d3UL, 0x61ef4192UL,
+    0x2eaed755UL, 0x37b5e614UL, 0x1c98b5d7UL, 0x05838496UL, 0x821b9859UL,
+    0x9b00a918UL, 0xb02dfadbUL, 0xa936cb9aUL, 0xe6775d5dUL, 0xff6c6c1cUL,
+    0xd4413fdfUL, 0xcd5a0e9eUL, 0x958424a2UL, 0x8c9f15e3UL, 0xa7b24620UL,
+    0xbea97761UL, 0xf1e8e1a6UL, 0xe8f3d0e7UL, 0xc3de8324UL, 0xdac5b265UL,
+    0x5d5daeaaUL, 0x44469febUL, 0x6f6bcc28UL, 0x7670fd69UL, 0x39316baeUL,
+    0x202a5aefUL, 0x0b07092cUL, 0x121c386dUL, 0xdf4636f3UL, 0xc65d07b2UL,
+    0xed705471UL, 0xf46b6530UL, 0xbb2af3f7UL, 0xa231c2b6UL, 0x891c9175UL,
+    0x9007a034UL, 0x179fbcfbUL, 0x0e848dbaUL, 0x25a9de79UL, 0x3cb2ef38UL,
+    0x73f379ffUL, 0x6ae848beUL, 0x41c51b7dUL, 0x58de2a3cUL, 0xf0794f05UL,
+    0xe9627e44UL, 0xc24f2d87UL, 0xdb541cc6UL, 0x94158a01UL, 0x8d0ebb40UL,
+    0xa623e883UL, 0xbf38d9c2UL, 0x38a0c50dUL, 0x21bbf44cUL, 0x0a96a78fUL,
+    0x138d96ceUL, 0x5ccc0009UL, 0x45d73148UL, 0x6efa628bUL, 0x77e153caUL,
+    0xbabb5d54UL, 0xa3a06c15UL, 0x888d3fd6UL, 0x91960e97UL, 0xded79850UL,
+    0xc7cca911UL, 0xece1fad2UL, 0xf5facb93UL, 0x7262d75cUL, 0x6b79e61dUL,
+    0x4054b5deUL, 0x594f849fUL, 0x160e1258UL, 0x0f152319UL, 0x243870daUL,
+    0x3d23419bUL, 0x65fd6ba7UL, 0x7ce65ae6UL, 0x57cb0925UL, 0x4ed03864UL,
+    0x0191aea3UL, 0x188a9fe2UL, 0x33a7cc21UL, 0x2abcfd60UL, 0xad24e1afUL,
+    0xb43fd0eeUL, 0x9f12832dUL, 0x8609b26cUL, 0xc94824abUL, 0xd05315eaUL,
+    0xfb7e4629UL, 0xe2657768UL, 0x2f3f79f6UL, 0x362448b7UL, 0x1d091b74UL,
+    0x04122a35UL, 0x4b53bcf2UL, 0x52488db3UL, 0x7965de70UL, 0x607eef31UL,
+    0xe7e6f3feUL, 0xfefdc2bfUL, 0xd5d0917cUL, 0xcccba03dUL, 0x838a36faUL,
+    0x9a9107bbUL, 0xb1bc5478UL, 0xa8a76539UL, 0x3b83984bUL, 0x2298a90aUL,
+    0x09b5fac9UL, 0x10aecb88UL, 0x5fef5d4fUL, 0x46f46c0eUL, 0x6dd93fcdUL,
+    0x74c20e8cUL, 0xf35a1243UL, 0xea412302UL, 0xc16c70c1UL, 0xd8774180UL,
+    0x9736d747UL, 0x8e2de606UL, 0xa500b5c5UL, 0xbc1b8484UL, 0x71418a1aUL,
+    0x685abb5bUL, 0x4377e898UL, 0x5a6cd9d9UL, 0x152d4f1eUL, 0x0c367e5fUL,
+    0x271b2d9cUL, 0x3e001cddUL, 0xb9980012UL, 0xa0833153UL, 0x8bae6290UL,
+    0x92b553d1UL, 0xddf4c516UL, 0xc4eff457UL, 0xefc2a794UL, 0xf6d996d5UL,
+    0xae07bce9UL, 0xb71c8da8UL, 0x9c31de6bUL, 0x852aef2aUL, 0xca6b79edUL,
+    0xd37048acUL, 0xf85d1b6fUL, 0xe1462a2eUL, 0x66de36e1UL, 0x7fc507a0UL,
+    0x54e85463UL, 0x4df36522UL, 0x02b2f3e5UL, 0x1ba9c2a4UL, 0x30849167UL,
+    0x299fa026UL, 0xe4c5aeb8UL, 0xfdde9ff9UL, 0xd6f3cc3aUL, 0xcfe8fd7bUL,
+    0x80a96bbcUL, 0x99b25afdUL, 0xb29f093eUL, 0xab84387fUL, 0x2c1c24b0UL,
+    0x350715f1UL, 0x1e2a4632UL, 0x07317773UL, 0x4870e1b4UL, 0x516bd0f5UL,
+    0x7a468336UL, 0x635db277UL, 0xcbfad74eUL, 0xd2e1e60fUL, 0xf9ccb5ccUL,
+    0xe0d7848dUL, 0xaf96124aUL, 0xb68d230bUL, 0x9da070c8UL, 0x84bb4189UL,
+    0x03235d46UL, 0x1a386c07UL, 0x31153fc4UL, 0x280e0e85UL, 0x674f9842UL,
+    0x7e54a903UL, 0x5579fac0UL, 0x4c62cb81UL, 0x8138c51fUL, 0x9823f45eUL,
+    0xb30ea79dUL, 0xaa1596dcUL, 0xe554001bUL, 0xfc4f315aUL, 0xd7626299UL,
+    0xce7953d8UL, 0x49e14f17UL, 0x50fa7e56UL, 0x7bd72d95UL, 0x62cc1cd4UL,
+    0x2d8d8a13UL, 0x3496bb52UL, 0x1fbbe891UL, 0x06a0d9d0UL, 0x5e7ef3ecUL,
+    0x4765c2adUL, 0x6c48916eUL, 0x7553a02fUL, 0x3a1236e8UL, 0x230907a9UL,
+    0x0824546aUL, 0x113f652bUL, 0x96a779e4UL, 0x8fbc48a5UL, 0xa4911b66UL,
+    0xbd8a2a27UL, 0xf2cbbce0UL, 0xebd08da1UL, 0xc0fdde62UL, 0xd9e6ef23UL,
+    0x14bce1bdUL, 0x0da7d0fcUL, 0x268a833fUL, 0x3f91b27eUL, 0x70d024b9UL,
+    0x69cb15f8UL, 0x42e6463bUL, 0x5bfd777aUL, 0xdc656bb5UL, 0xc57e5af4UL,
+    0xee530937UL, 0xf7483876UL, 0xb809aeb1UL, 0xa1129ff0UL, 0x8a3fcc33UL,
+    0x9324fd72UL
+  },
+  {
+    0x00000000UL, 0x01c26a37UL, 0x0384d46eUL, 0x0246be59UL, 0x0709a8dcUL,
+    0x06cbc2ebUL, 0x048d7cb2UL, 0x054f1685UL, 0x0e1351b8UL, 0x0fd13b8fUL,
+    0x0d9785d6UL, 0x0c55efe1UL, 0x091af964UL, 0x08d89353UL, 0x0a9e2d0aUL,
+    0x0b5c473dUL, 0x1c26a370UL, 0x1de4c947UL, 0x1fa2771eUL, 0x1e601d29UL,
+    0x1b2f0bacUL, 0x1aed619bUL, 0x18abdfc2UL, 0x1969b5f5UL, 0x1235f2c8UL,
+    0x13f798ffUL, 0x11b126a6UL, 0x10734c91UL, 0x153c5a14UL, 0x14fe3023UL,
+    0x16b88e7aUL, 0x177ae44dUL, 0x384d46e0UL, 0x398f2cd7UL, 0x3bc9928eUL,
+    0x3a0bf8b9UL, 0x3f44ee3cUL, 0x3e86840bUL, 0x3cc03a52UL, 0x3d025065UL,
+    0x365e1758UL, 0x379c7d6fUL, 0x35dac336UL, 0x3418a901UL, 0x3157bf84UL,
+    0x3095d5b3UL, 0x32d36beaUL, 0x331101ddUL, 0x246be590UL, 0x25a98fa7UL,
+    0x27ef31feUL, 0x262d5bc9UL, 0x23624d4cUL, 0x22a0277bUL, 0x20e69922UL,
+    0x2124f315UL, 0x2a78b428UL, 0x2bbade1fUL, 0x29fc6046UL, 0x283e0a71UL,
+    0x2d711cf4UL, 0x2cb376c3UL, 0x2ef5c89aUL, 0x2f37a2adUL, 0x709a8dc0UL,
+    0x7158e7f7UL, 0x731e59aeUL, 0x72dc3399UL, 0x7793251cUL, 0x76514f2bUL,
+    0x7417f172UL, 0x75d59b45UL, 0x7e89dc78UL, 0x7f4bb64fUL, 0x7d0d0816UL,
+    0x7ccf6221UL, 0x798074a4UL, 0x78421e93UL, 0x7a04a0caUL, 0x7bc6cafdUL,
+    0x6cbc2eb0UL, 0x6d7e4487UL, 0x6f38fadeUL, 0x6efa90e9UL, 0x6bb5866cUL,
+    0x6a77ec5bUL, 0x68315202UL, 0x69f33835UL, 0x62af7f08UL, 0x636d153fUL,
+    0x612bab66UL, 0x60e9c151UL, 0x65a6d7d4UL, 0x6464bde3UL, 0x662203baUL,
+    0x67e0698dUL, 0x48d7cb20UL, 0x4915a117UL, 0x4b531f4eUL, 0x4a917579UL,
+    0x4fde63fcUL, 0x4e1c09cbUL, 0x4c5ab792UL, 0x4d98dda5UL, 0x46c49a98UL,
+    0x4706f0afUL, 0x45404ef6UL, 0x448224c1UL, 0x41cd3244UL, 0x400f5873UL,
+    0x4249e62aUL, 0x438b8c1dUL, 0x54f16850UL, 0x55330267UL, 0x5775bc3eUL,
+    0x56b7d609UL, 0x53f8c08cUL, 0x523aaabbUL, 0x507c14e2UL, 0x51be7ed5UL,
+    0x5ae239e8UL, 0x5b2053dfUL, 0x5966ed86UL, 0x58a487b1UL, 0x5deb9134UL,
+    0x5c29fb03UL, 0x5e6f455aUL, 0x5fad2f6dUL, 0xe1351b80UL, 0xe0f771b7UL,
+    0xe2b1cfeeUL, 0xe373a5d9UL, 0xe63cb35cUL, 0xe7fed96bUL, 0xe5b86732UL,
+    0xe47a0d05UL, 0xef264a38UL, 0xeee4200fUL, 0xeca29e56UL, 0xed60f461UL,
+    0xe82fe2e4UL, 0xe9ed88d3UL, 0xebab368aUL, 0xea695cbdUL, 0xfd13b8f0UL,
+    0xfcd1d2c7UL, 0xfe976c9eUL, 0xff5506a9UL, 0xfa1a102cUL, 0xfbd87a1bUL,
+    0xf99ec442UL, 0xf85cae75UL, 0xf300e948UL, 0xf2c2837fUL, 0xf0843d26UL,
+    0xf1465711UL, 0xf4094194UL, 0xf5cb2ba3UL, 0xf78d95faUL, 0xf64fffcdUL,
+    0xd9785d60UL, 0xd8ba3757UL, 0xdafc890eUL, 0xdb3ee339UL, 0xde71f5bcUL,
+    0xdfb39f8bUL, 0xddf521d2UL, 0xdc374be5UL, 0xd76b0cd8UL, 0xd6a966efUL,
+    0xd4efd8b6UL, 0xd52db281UL, 0xd062a404UL, 0xd1a0ce33UL, 0xd3e6706aUL,
+    0xd2241a5dUL, 0xc55efe10UL, 0xc49c9427UL, 0xc6da2a7eUL, 0xc7184049UL,
+    0xc25756ccUL, 0xc3953cfbUL, 0xc1d382a2UL, 0xc011e895UL, 0xcb4dafa8UL,
+    0xca8fc59fUL, 0xc8c97bc6UL, 0xc90b11f1UL, 0xcc440774UL, 0xcd866d43UL,
+    0xcfc0d31aUL, 0xce02b92dUL, 0x91af9640UL, 0x906dfc77UL, 0x922b422eUL,
+    0x93e92819UL, 0x96a63e9cUL, 0x976454abUL, 0x9522eaf2UL, 0x94e080c5UL,
+    0x9fbcc7f8UL, 0x9e7eadcfUL, 0x9c381396UL, 0x9dfa79a1UL, 0x98b56f24UL,
+    0x99770513UL, 0x9b31bb4aUL, 0x9af3d17dUL, 0x8d893530UL, 0x8c4b5f07UL,
+    0x8e0de15eUL, 0x8fcf8b69UL, 0x8a809decUL, 0x8b42f7dbUL, 0x89044982UL,
+    0x88c623b5UL, 0x839a6488UL, 0x82580ebfUL, 0x801eb0e6UL, 0x81dcdad1UL,
+    0x8493cc54UL, 0x8551a663UL, 0x8717183aUL, 0x86d5720dUL, 0xa9e2d0a0UL,
+    0xa820ba97UL, 0xaa6604ceUL, 0xaba46ef9UL, 0xaeeb787cUL, 0xaf29124bUL,
+    0xad6fac12UL, 0xacadc625UL, 0xa7f18118UL, 0xa633eb2fUL, 0xa4755576UL,
+    0xa5b73f41UL, 0xa0f829c4UL, 0xa13a43f3UL, 0xa37cfdaaUL, 0xa2be979dUL,
+    0xb5c473d0UL, 0xb40619e7UL, 0xb640a7beUL, 0xb782cd89UL, 0xb2cddb0cUL,
+    0xb30fb13bUL, 0xb1490f62UL, 0xb08b6555UL, 0xbbd72268UL, 0xba15485fUL,
+    0xb853f606UL, 0xb9919c31UL, 0xbcde8ab4UL, 0xbd1ce083UL, 0xbf5a5edaUL,
+    0xbe9834edUL
+  },
+  {
+    0x00000000UL, 0xb8bc6765UL, 0xaa09c88bUL, 0x12b5afeeUL, 0x8f629757UL,
+    0x37def032UL, 0x256b5fdcUL, 0x9dd738b9UL, 0xc5b428efUL, 0x7d084f8aUL,
+    0x6fbde064UL, 0xd7018701UL, 0x4ad6bfb8UL, 0xf26ad8ddUL, 0xe0df7733UL,
+    0x58631056UL, 0x5019579fUL, 0xe8a530faUL, 0xfa109f14UL, 0x42acf871UL,
+    0xdf7bc0c8UL, 0x67c7a7adUL, 0x75720843UL, 0xcdce6f26UL, 0x95ad7f70UL,
+    0x2d111815UL, 0x3fa4b7fbUL, 0x8718d09eUL, 0x1acfe827UL, 0xa2738f42UL,
+    0xb0c620acUL, 0x087a47c9UL, 0xa032af3eUL, 0x188ec85bUL, 0x0a3b67b5UL,
+    0xb28700d0UL, 0x2f503869UL, 0x97ec5f0cUL, 0x8559f0e2UL, 0x3de59787UL,
+    0x658687d1UL, 0xdd3ae0b4UL, 0xcf8f4f5aUL, 0x7733283fUL, 0xeae41086UL,
+    0x525877e3UL, 0x40edd80dUL, 0xf851bf68UL, 0xf02bf8a1UL, 0x48979fc4UL,
+    0x5a22302aUL, 0xe29e574fUL, 0x7f496ff6UL, 0xc7f50893UL, 0xd540a77dUL,
+    0x6dfcc018UL, 0x359fd04eUL, 0x8d23b72bUL, 0x9f9618c5UL, 0x272a7fa0UL,
+    0xbafd4719UL, 0x0241207cUL, 0x10f48f92UL, 0xa848e8f7UL, 0x9b14583dUL,
+    0x23a83f58UL, 0x311d90b6UL, 0x89a1f7d3UL, 0x1476cf6aUL, 0xaccaa80fUL,
+    0xbe7f07e1UL, 0x06c36084UL, 0x5ea070d2UL, 0xe61c17b7UL, 0xf4a9b859UL,
+    0x4c15df3cUL, 0xd1c2e785UL, 0x697e80e0UL, 0x7bcb2f0eUL, 0xc377486bUL,
+    0xcb0d0fa2UL, 0x73b168c7UL, 0x6104c729UL, 0xd9b8a04cUL, 0x446f98f5UL,
+    0xfcd3ff90UL, 0xee66507eUL, 0x56da371bUL, 0x0eb9274dUL, 0xb6054028UL,
+    0xa4b0efc6UL, 0x1c0c88a3UL, 0x81dbb01aUL, 0x3967d77fUL, 0x2bd27891UL,
+    0x936e1ff4UL, 0x3b26f703UL, 0x839a9066UL, 0x912f3f88UL, 0x299358edUL,
+    0xb4446054UL, 0x0cf80731UL, 0x1e4da8dfUL, 0xa6f1cfbaUL, 0xfe92dfecUL,
+    0x462eb889UL, 0x549b1767UL, 0xec277002UL, 0x71f048bbUL, 0xc94c2fdeUL,
+    0xdbf98030UL, 0x6345e755UL, 0x6b3fa09cUL, 0xd383c7f9UL, 0xc1366817UL,
+    0x798a0f72UL, 0xe45d37cbUL, 0x5ce150aeUL, 0x4e54ff40UL, 0xf6e89825UL,
+    0xae8b8873UL, 0x1637ef16UL, 0x048240f8UL, 0xbc3e279dUL, 0x21e91f24UL,
+    0x99557841UL, 0x8be0d7afUL, 0x335cb0caUL, 0xed59b63bUL, 0x55e5d15eUL,
+    0x47507eb0UL, 0xffec19d5UL, 0x623b216cUL, 0xda874609UL, 0xc832e9e7UL,
+    0x708e8e82UL, 0x28ed9ed4UL, 0x9051f9b1UL, 0x82e4565fUL, 0x3a58313aUL,
+    0xa78f0983UL, 0x1f336ee6UL, 0x0d86c108UL, 0xb53aa66dUL, 0xbd40e1a4UL,
+    0x05fc86c1UL, 0x1749292fUL, 0xaff54e4aUL, 0x322276f3UL, 0x8a9e1196UL,
+    0x982bbe78UL, 0x2097d91dUL, 0x78f4c94bUL, 0xc048ae2eUL, 0xd2fd01c0UL,
+    0x6a4166a5UL, 0xf7965e1cUL, 0x4f2a3979UL, 0x5d9f9697UL, 0xe523f1f2UL,
+    0x4d6b1905UL, 0xf5d77e60UL, 0xe762d18eUL, 0x5fdeb6ebUL, 0xc2098e52UL,
+    0x7ab5e937UL, 0x680046d9UL, 0xd0bc21bcUL, 0x88df31eaUL, 0x3063568fUL,
+    0x22d6f961UL, 0x9a6a9e04UL, 0x07bda6bdUL, 0xbf01c1d8UL, 0xadb46e36UL,
+    0x15080953UL, 0x1d724e9aUL, 0xa5ce29ffUL, 0xb77b8611UL, 0x0fc7e174UL,
+    0x9210d9cdUL, 0x2aacbea8UL, 0x38191146UL, 0x80a57623UL, 0xd8c66675UL,
+    0x607a0110UL, 0x72cfaefeUL, 0xca73c99bUL, 0x57a4f122UL, 0xef189647UL,
+    0xfdad39a9UL, 0x45115eccUL, 0x764dee06UL, 0xcef18963UL, 0xdc44268dUL,
+    0x64f841e8UL, 0xf92f7951UL, 0x41931e34UL, 0x5326b1daUL, 0xeb9ad6bfUL,
+    0xb3f9c6e9UL, 0x0b45a18cUL, 0x19f00e62UL, 0xa14c6907UL, 0x3c9b51beUL,
+    0x842736dbUL, 0x96929935UL, 0x2e2efe50UL, 0x2654b999UL, 0x9ee8defcUL,
+    0x8c5d7112UL, 0x34e11677UL, 0xa9362eceUL, 0x118a49abUL, 0x033fe645UL,
+    0xbb838120UL, 0xe3e09176UL, 0x5b5cf613UL, 0x49e959fdUL, 0xf1553e98UL,
+    0x6c820621UL, 0xd43e6144UL, 0xc68bceaaUL, 0x7e37a9cfUL, 0xd67f4138UL,
+    0x6ec3265dUL, 0x7c7689b3UL, 0xc4caeed6UL, 0x591dd66fUL, 0xe1a1b10aUL,
+    0xf3141ee4UL, 0x4ba87981UL, 0x13cb69d7UL, 0xab770eb2UL, 0xb9c2a15cUL,
+    0x017ec639UL, 0x9ca9fe80UL, 0x241599e5UL, 0x36a0360bUL, 0x8e1c516eUL,
+    0x866616a7UL, 0x3eda71c2UL, 0x2c6fde2cUL, 0x94d3b949UL, 0x090481f0UL,
+    0xb1b8e695UL, 0xa30d497bUL, 0x1bb12e1eUL, 0x43d23e48UL, 0xfb6e592dUL,
+    0xe9dbf6c3UL, 0x516791a6UL, 0xccb0a91fUL, 0x740cce7aUL, 0x66b96194UL,
+    0xde0506f1UL
+  },
+  {
+    0x00000000UL, 0x96300777UL, 0x2c610eeeUL, 0xba510999UL, 0x19c46d07UL,
+    0x8ff46a70UL, 0x35a563e9UL, 0xa395649eUL, 0x3288db0eUL, 0xa4b8dc79UL,
+    0x1ee9d5e0UL, 0x88d9d297UL, 0x2b4cb609UL, 0xbd7cb17eUL, 0x072db8e7UL,
+    0x911dbf90UL, 0x6410b71dUL, 0xf220b06aUL, 0x4871b9f3UL, 0xde41be84UL,
+    0x7dd4da1aUL, 0xebe4dd6dUL, 0x51b5d4f4UL, 0xc785d383UL, 0x56986c13UL,
+    0xc0a86b64UL, 0x7af962fdUL, 0xecc9658aUL, 0x4f5c0114UL, 0xd96c0663UL,
+    0x633d0ffaUL, 0xf50d088dUL, 0xc8206e3bUL, 0x5e10694cUL, 0xe44160d5UL,
+    0x727167a2UL, 0xd1e4033cUL, 0x47d4044bUL, 0xfd850dd2UL, 0x6bb50aa5UL,
+    0xfaa8b535UL, 0x6c98b242UL, 0xd6c9bbdbUL, 0x40f9bcacUL, 0xe36cd832UL,
+    0x755cdf45UL, 0xcf0dd6dcUL, 0x593dd1abUL, 0xac30d926UL, 0x3a00de51UL,
+    0x8051d7c8UL, 0x1661d0bfUL, 0xb5f4b421UL, 0x23c4b356UL, 0x9995bacfUL,
+    0x0fa5bdb8UL, 0x9eb80228UL, 0x0888055fUL, 0xb2d90cc6UL, 0x24e90bb1UL,
+    0x877c6f2fUL, 0x114c6858UL, 0xab1d61c1UL, 0x3d2d66b6UL, 0x9041dc76UL,
+    0x0671db01UL, 0xbc20d298UL, 0x2a10d5efUL, 0x8985b171UL, 0x1fb5b606UL,
+    0xa5e4bf9fUL, 0x33d4b8e8UL, 0xa2c90778UL, 0x34f9000fUL, 0x8ea80996UL,
+    0x18980ee1UL, 0xbb0d6a7fUL, 0x2d3d6d08UL, 0x976c6491UL, 0x015c63e6UL,
+    0xf4516b6bUL, 0x62616c1cUL, 0xd8306585UL, 0x4e0062f2UL, 0xed95066cUL,
+    0x7ba5011bUL, 0xc1f40882UL, 0x57c40ff5UL, 0xc6d9b065UL, 0x50e9b712UL,
+    0xeab8be8bUL, 0x7c88b9fcUL, 0xdf1ddd62UL, 0x492dda15UL, 0xf37cd38cUL,
+    0x654cd4fbUL, 0x5861b24dUL, 0xce51b53aUL, 0x7400bca3UL, 0xe230bbd4UL,
+    0x41a5df4aUL, 0xd795d83dUL, 0x6dc4d1a4UL, 0xfbf4d6d3UL, 0x6ae96943UL,
+    0xfcd96e34UL, 0x468867adUL, 0xd0b860daUL, 0x732d0444UL, 0xe51d0333UL,
+    0x5f4c0aaaUL, 0xc97c0dddUL, 0x3c710550UL, 0xaa410227UL, 0x10100bbeUL,
+    0x86200cc9UL, 0x25b56857UL, 0xb3856f20UL, 0x09d466b9UL, 0x9fe461ceUL,
+    0x0ef9de5eUL, 0x98c9d929UL, 0x2298d0b0UL, 0xb4a8d7c7UL, 0x173db359UL,
+    0x810db42eUL, 0x3b5cbdb7UL, 0xad6cbac0UL, 0x2083b8edUL, 0xb6b3bf9aUL,
+    0x0ce2b603UL, 0x9ad2b174UL, 0x3947d5eaUL, 0xaf77d29dUL, 0x1526db04UL,
+    0x8316dc73UL, 0x120b63e3UL, 0x843b6494UL, 0x3e6a6d0dUL, 0xa85a6a7aUL,
+    0x0bcf0ee4UL, 0x9dff0993UL, 0x27ae000aUL, 0xb19e077dUL, 0x44930ff0UL,
+    0xd2a30887UL, 0x68f2011eUL, 0xfec20669UL, 0x5d5762f7UL, 0xcb676580UL,
+    0x71366c19UL, 0xe7066b6eUL, 0x761bd4feUL, 0xe02bd389UL, 0x5a7ada10UL,
+    0xcc4add67UL, 0x6fdfb9f9UL, 0xf9efbe8eUL, 0x43beb717UL, 0xd58eb060UL,
+    0xe8a3d6d6UL, 0x7e93d1a1UL, 0xc4c2d838UL, 0x52f2df4fUL, 0xf167bbd1UL,
+    0x6757bca6UL, 0xdd06b53fUL, 0x4b36b248UL, 0xda2b0dd8UL, 0x4c1b0aafUL,
+    0xf64a0336UL, 0x607a0441UL, 0xc3ef60dfUL, 0x55df67a8UL, 0xef8e6e31UL,
+    0x79be6946UL, 0x8cb361cbUL, 0x1a8366bcUL, 0xa0d26f25UL, 0x36e26852UL,
+    0x95770cccUL, 0x03470bbbUL, 0xb9160222UL, 0x2f260555UL, 0xbe3bbac5UL,
+    0x280bbdb2UL, 0x925ab42bUL, 0x046ab35cUL, 0xa7ffd7c2UL, 0x31cfd0b5UL,
+    0x8b9ed92cUL, 0x1daede5bUL, 0xb0c2649bUL, 0x26f263ecUL, 0x9ca36a75UL,
+    0x0a936d02UL, 0xa906099cUL, 0x3f360eebUL, 0x85670772UL, 0x13570005UL,
+    0x824abf95UL, 0x147ab8e2UL, 0xae2bb17bUL, 0x381bb60cUL, 0x9b8ed292UL,
+    0x0dbed5e5UL, 0xb7efdc7cUL, 0x21dfdb0bUL, 0xd4d2d386UL, 0x42e2d4f1UL,
+    0xf8b3dd68UL, 0x6e83da1fUL, 0xcd16be81UL, 0x5b26b9f6UL, 0xe177b06fUL,
+    0x7747b718UL, 0xe65a0888UL, 0x706a0fffUL, 0xca3b0666UL, 0x5c0b0111UL,
+    0xff9e658fUL, 0x69ae62f8UL, 0xd3ff6b61UL, 0x45cf6c16UL, 0x78e20aa0UL,
+    0xeed20dd7UL, 0x5483044eUL, 0xc2b30339UL, 0x612667a7UL, 0xf71660d0UL,
+    0x4d476949UL, 0xdb776e3eUL, 0x4a6ad1aeUL, 0xdc5ad6d9UL, 0x660bdf40UL,
+    0xf03bd837UL, 0x53aebca9UL, 0xc59ebbdeUL, 0x7fcfb247UL, 0xe9ffb530UL,
+    0x1cf2bdbdUL, 0x8ac2bacaUL, 0x3093b353UL, 0xa6a3b424UL, 0x0536d0baUL,
+    0x9306d7cdUL, 0x2957de54UL, 0xbf67d923UL, 0x2e7a66b3UL, 0xb84a61c4UL,
+    0x021b685dUL, 0x942b6f2aUL, 0x37be0bb4UL, 0xa18e0cc3UL, 0x1bdf055aUL,
+    0x8def022dUL
+  },
+  {
+    0x00000000UL, 0x41311b19UL, 0x82623632UL, 0xc3532d2bUL, 0x04c56c64UL,
+    0x45f4777dUL, 0x86a75a56UL, 0xc796414fUL, 0x088ad9c8UL, 0x49bbc2d1UL,
+    0x8ae8effaUL, 0xcbd9f4e3UL, 0x0c4fb5acUL, 0x4d7eaeb5UL, 0x8e2d839eUL,
+    0xcf1c9887UL, 0x5112c24aUL, 0x1023d953UL, 0xd370f478UL, 0x9241ef61UL,
+    0x55d7ae2eUL, 0x14e6b537UL, 0xd7b5981cUL, 0x96848305UL, 0x59981b82UL,
+    0x18a9009bUL, 0xdbfa2db0UL, 0x9acb36a9UL, 0x5d5d77e6UL, 0x1c6c6cffUL,
+    0xdf3f41d4UL, 0x9e0e5acdUL, 0xa2248495UL, 0xe3159f8cUL, 0x2046b2a7UL,
+    0x6177a9beUL, 0xa6e1e8f1UL, 0xe7d0f3e8UL, 0x2483dec3UL, 0x65b2c5daUL,
+    0xaaae5d5dUL, 0xeb9f4644UL, 0x28cc6b6fUL, 0x69fd7076UL, 0xae6b3139UL,
+    0xef5a2a20UL, 0x2c09070bUL, 0x6d381c12UL, 0xf33646dfUL, 0xb2075dc6UL,
+    0x715470edUL, 0x30656bf4UL, 0xf7f32abbUL, 0xb6c231a2UL, 0x75911c89UL,
+    0x34a00790UL, 0xfbbc9f17UL, 0xba8d840eUL, 0x79dea925UL, 0x38efb23cUL,
+    0xff79f373UL, 0xbe48e86aUL, 0x7d1bc541UL, 0x3c2ade58UL, 0x054f79f0UL,
+    0x447e62e9UL, 0x872d4fc2UL, 0xc61c54dbUL, 0x018a1594UL, 0x40bb0e8dUL,
+    0x83e823a6UL, 0xc2d938bfUL, 0x0dc5a038UL, 0x4cf4bb21UL, 0x8fa7960aUL,
+    0xce968d13UL, 0x0900cc5cUL, 0x4831d745UL, 0x8b62fa6eUL, 0xca53e177UL,
+    0x545dbbbaUL, 0x156ca0a3UL, 0xd63f8d88UL, 0x970e9691UL, 0x5098d7deUL,
+    0x11a9ccc7UL, 0xd2fae1ecUL, 0x93cbfaf5UL, 0x5cd76272UL, 0x1de6796bUL,
+    0xdeb55440UL, 0x9f844f59UL, 0x58120e16UL, 0x1923150fUL, 0xda703824UL,
+    0x9b41233dUL, 0xa76bfd65UL, 0xe65ae67cUL, 0x2509cb57UL, 0x6438d04eUL,
+    0xa3ae9101UL, 0xe29f8a18UL, 0x21cca733UL, 0x60fdbc2aUL, 0xafe124adUL,
+    0xeed03fb4UL, 0x2d83129fUL, 0x6cb20986UL, 0xab2448c9UL, 0xea1553d0UL,
+    0x29467efbUL, 0x687765e2UL, 0xf6793f2fUL, 0xb7482436UL, 0x741b091dUL,
+    0x352a1204UL, 0xf2bc534bUL, 0xb38d4852UL, 0x70de6579UL, 0x31ef7e60UL,
+    0xfef3e6e7UL, 0xbfc2fdfeUL, 0x7c91d0d5UL, 0x3da0cbccUL, 0xfa368a83UL,
+    0xbb07919aUL, 0x7854bcb1UL, 0x3965a7a8UL, 0x4b98833bUL, 0x0aa99822UL,
+    0xc9fab509UL, 0x88cbae10UL, 0x4f5def5fUL, 0x0e6cf446UL, 0xcd3fd96dUL,
+    0x8c0ec274UL, 0x43125af3UL, 0x022341eaUL, 0xc1706cc1UL, 0x804177d8UL,
+    0x47d73697UL, 0x06e62d8eUL, 0xc5b500a5UL, 0x84841bbcUL, 0x1a8a4171UL,
+    0x5bbb5a68UL, 0x98e87743UL, 0xd9d96c5aUL, 0x1e4f2d15UL, 0x5f7e360cUL,
+    0x9c2d1b27UL, 0xdd1c003eUL, 0x120098b9UL, 0x533183a0UL, 0x9062ae8bUL,
+    0xd153b592UL, 0x16c5f4ddUL, 0x57f4efc4UL, 0x94a7c2efUL, 0xd596d9f6UL,
+    0xe9bc07aeUL, 0xa88d1cb7UL, 0x6bde319cUL, 0x2aef2a85UL, 0xed796bcaUL,
+    0xac4870d3UL, 0x6f1b5df8UL, 0x2e2a46e1UL, 0xe136de66UL, 0xa007c57fUL,
+    0x6354e854UL, 0x2265f34dUL, 0xe5f3b202UL, 0xa4c2a91bUL, 0x67918430UL,
+    0x26a09f29UL, 0xb8aec5e4UL, 0xf99fdefdUL, 0x3accf3d6UL, 0x7bfde8cfUL,
+    0xbc6ba980UL, 0xfd5ab299UL, 0x3e099fb2UL, 0x7f3884abUL, 0xb0241c2cUL,
+    0xf1150735UL, 0x32462a1eUL, 0x73773107UL, 0xb4e17048UL, 0xf5d06b51UL,
+    0x3683467aUL, 0x77b25d63UL, 0x4ed7facbUL, 0x0fe6e1d2UL, 0xccb5ccf9UL,
+    0x8d84d7e0UL, 0x4a1296afUL, 0x0b238db6UL, 0xc870a09dUL, 0x8941bb84UL,
+    0x465d2303UL, 0x076c381aUL, 0xc43f1531UL, 0x850e0e28UL, 0x42984f67UL,
+    0x03a9547eUL, 0xc0fa7955UL, 0x81cb624cUL, 0x1fc53881UL, 0x5ef42398UL,
+    0x9da70eb3UL, 0xdc9615aaUL, 0x1b0054e5UL, 0x5a314ffcUL, 0x996262d7UL,
+    0xd85379ceUL, 0x174fe149UL, 0x567efa50UL, 0x952dd77bUL, 0xd41ccc62UL,
+    0x138a8d2dUL, 0x52bb9634UL, 0x91e8bb1fUL, 0xd0d9a006UL, 0xecf37e5eUL,
+    0xadc26547UL, 0x6e91486cUL, 0x2fa05375UL, 0xe836123aUL, 0xa9070923UL,
+    0x6a542408UL, 0x2b653f11UL, 0xe479a796UL, 0xa548bc8fUL, 0x661b91a4UL,
+    0x272a8abdUL, 0xe0bccbf2UL, 0xa18dd0ebUL, 0x62defdc0UL, 0x23efe6d9UL,
+    0xbde1bc14UL, 0xfcd0a70dUL, 0x3f838a26UL, 0x7eb2913fUL, 0xb924d070UL,
+    0xf815cb69UL, 0x3b46e642UL, 0x7a77fd5bUL, 0xb56b65dcUL, 0xf45a7ec5UL,
+    0x370953eeUL, 0x763848f7UL, 0xb1ae09b8UL, 0xf09f12a1UL, 0x33cc3f8aUL,
+    0x72fd2493UL
+  },
+  {
+    0x00000000UL, 0x376ac201UL, 0x6ed48403UL, 0x59be4602UL, 0xdca80907UL,
+    0xebc2cb06UL, 0xb27c8d04UL, 0x85164f05UL, 0xb851130eUL, 0x8f3bd10fUL,
+    0xd685970dUL, 0xe1ef550cUL, 0x64f91a09UL, 0x5393d808UL, 0x0a2d9e0aUL,
+    0x3d475c0bUL, 0x70a3261cUL, 0x47c9e41dUL, 0x1e77a21fUL, 0x291d601eUL,
+    0xac0b2f1bUL, 0x9b61ed1aUL, 0xc2dfab18UL, 0xf5b56919UL, 0xc8f23512UL,
+    0xff98f713UL, 0xa626b111UL, 0x914c7310UL, 0x145a3c15UL, 0x2330fe14UL,
+    0x7a8eb816UL, 0x4de47a17UL, 0xe0464d38UL, 0xd72c8f39UL, 0x8e92c93bUL,
+    0xb9f80b3aUL, 0x3cee443fUL, 0x0b84863eUL, 0x523ac03cUL, 0x6550023dUL,
+    0x58175e36UL, 0x6f7d9c37UL, 0x36c3da35UL, 0x01a91834UL, 0x84bf5731UL,
+    0xb3d59530UL, 0xea6bd332UL, 0xdd011133UL, 0x90e56b24UL, 0xa78fa925UL,
+    0xfe31ef27UL, 0xc95b2d26UL, 0x4c4d6223UL, 0x7b27a022UL, 0x2299e620UL,
+    0x15f32421UL, 0x28b4782aUL, 0x1fdeba2bUL, 0x4660fc29UL, 0x710a3e28UL,
+    0xf41c712dUL, 0xc376b32cUL, 0x9ac8f52eUL, 0xada2372fUL, 0xc08d9a70UL,
+    0xf7e75871UL, 0xae591e73UL, 0x9933dc72UL, 0x1c259377UL, 0x2b4f5176UL,
+    0x72f11774UL, 0x459bd575UL, 0x78dc897eUL, 0x4fb64b7fUL, 0x16080d7dUL,
+    0x2162cf7cUL, 0xa4748079UL, 0x931e4278UL, 0xcaa0047aUL, 0xfdcac67bUL,
+    0xb02ebc6cUL, 0x87447e6dUL, 0xdefa386fUL, 0xe990fa6eUL, 0x6c86b56bUL,
+    0x5bec776aUL, 0x02523168UL, 0x3538f369UL, 0x087faf62UL, 0x3f156d63UL,
+    0x66ab2b61UL, 0x51c1e960UL, 0xd4d7a665UL, 0xe3bd6464UL, 0xba032266UL,
+    0x8d69e067UL, 0x20cbd748UL, 0x17a11549UL, 0x4e1f534bUL, 0x7975914aUL,
+    0xfc63de4fUL, 0xcb091c4eUL, 0x92b75a4cUL, 0xa5dd984dUL, 0x989ac446UL,
+    0xaff00647UL, 0xf64e4045UL, 0xc1248244UL, 0x4432cd41UL, 0x73580f40UL,
+    0x2ae64942UL, 0x1d8c8b43UL, 0x5068f154UL, 0x67023355UL, 0x3ebc7557UL,
+    0x09d6b756UL, 0x8cc0f853UL, 0xbbaa3a52UL, 0xe2147c50UL, 0xd57ebe51UL,
+    0xe839e25aUL, 0xdf53205bUL, 0x86ed6659UL, 0xb187a458UL, 0x3491eb5dUL,
+    0x03fb295cUL, 0x5a456f5eUL, 0x6d2fad5fUL, 0x801b35e1UL, 0xb771f7e0UL,
+    0xeecfb1e2UL, 0xd9a573e3UL, 0x5cb33ce6UL, 0x6bd9fee7UL, 0x3267b8e5UL,
+    0x050d7ae4UL, 0x384a26efUL, 0x0f20e4eeUL, 0x569ea2ecUL, 0x61f460edUL,
+    0xe4e22fe8UL, 0xd388ede9UL, 0x8a36abebUL, 0xbd5c69eaUL, 0xf0b813fdUL,
+    0xc7d2d1fcUL, 0x9e6c97feUL, 0xa90655ffUL, 0x2c101afaUL, 0x1b7ad8fbUL,
+    0x42c49ef9UL, 0x75ae5cf8UL, 0x48e900f3UL, 0x7f83c2f2UL, 0x263d84f0UL,
+    0x115746f1UL, 0x944109f4UL, 0xa32bcbf5UL, 0xfa958df7UL, 0xcdff4ff6UL,
+    0x605d78d9UL, 0x5737bad8UL, 0x0e89fcdaUL, 0x39e33edbUL, 0xbcf571deUL,
+    0x8b9fb3dfUL, 0xd221f5ddUL, 0xe54b37dcUL, 0xd80c6bd7UL, 0xef66a9d6UL,
+    0xb6d8efd4UL, 0x81b22dd5UL, 0x04a462d0UL, 0x33cea0d1UL, 0x6a70e6d3UL,
+    0x5d1a24d2UL, 0x10fe5ec5UL, 0x27949cc4UL, 0x7e2adac6UL, 0x494018c7UL,
+    0xcc5657c2UL, 0xfb3c95c3UL, 0xa282d3c1UL, 0x95e811c0UL, 0xa8af4dcbUL,
+    0x9fc58fcaUL, 0xc67bc9c8UL, 0xf1110bc9UL, 0x740744ccUL, 0x436d86cdUL,
+    0x1ad3c0cfUL, 0x2db902ceUL, 0x4096af91UL, 0x77fc6d90UL, 0x2e422b92UL,
+    0x1928e993UL, 0x9c3ea696UL, 0xab546497UL, 0xf2ea2295UL, 0xc580e094UL,
+    0xf8c7bc9fUL, 0xcfad7e9eUL, 0x9613389cUL, 0xa179fa9dUL, 0x246fb598UL,
+    0x13057799UL, 0x4abb319bUL, 0x7dd1f39aUL, 0x3035898dUL, 0x075f4b8cUL,
+    0x5ee10d8eUL, 0x698bcf8fUL, 0xec9d808aUL, 0xdbf7428bUL, 0x82490489UL,
+    0xb523c688UL, 0x88649a83UL, 0xbf0e5882UL, 0xe6b01e80UL, 0xd1dadc81UL,
+    0x54cc9384UL, 0x63a65185UL, 0x3a181787UL, 0x0d72d586UL, 0xa0d0e2a9UL,
+    0x97ba20a8UL, 0xce0466aaUL, 0xf96ea4abUL, 0x7c78ebaeUL, 0x4b1229afUL,
+    0x12ac6fadUL, 0x25c6adacUL, 0x1881f1a7UL, 0x2feb33a6UL, 0x765575a4UL,
+    0x413fb7a5UL, 0xc429f8a0UL, 0xf3433aa1UL, 0xaafd7ca3UL, 0x9d97bea2UL,
+    0xd073c4b5UL, 0xe71906b4UL, 0xbea740b6UL, 0x89cd82b7UL, 0x0cdbcdb2UL,
+    0x3bb10fb3UL, 0x620f49b1UL, 0x55658bb0UL, 0x6822d7bbUL, 0x5f4815baUL,
+    0x06f653b8UL, 0x319c91b9UL, 0xb48adebcUL, 0x83e01cbdUL, 0xda5e5abfUL,
+    0xed3498beUL
+  },
+  {
+    0x00000000UL, 0x6567bcb8UL, 0x8bc809aaUL, 0xeeafb512UL, 0x5797628fUL,
+    0x32f0de37UL, 0xdc5f6b25UL, 0xb938d79dUL, 0xef28b4c5UL, 0x8a4f087dUL,
+    0x64e0bd6fUL, 0x018701d7UL, 0xb8bfd64aUL, 0xddd86af2UL, 0x3377dfe0UL,
+    0x56106358UL, 0x9f571950UL, 0xfa30a5e8UL, 0x149f10faUL, 0x71f8ac42UL,
+    0xc8c07bdfUL, 0xada7c767UL, 0x43087275UL, 0x266fcecdUL, 0x707fad95UL,
+    0x1518112dUL, 0xfbb7a43fUL, 0x9ed01887UL, 0x27e8cf1aUL, 0x428f73a2UL,
+    0xac20c6b0UL, 0xc9477a08UL, 0x3eaf32a0UL, 0x5bc88e18UL, 0xb5673b0aUL,
+    0xd00087b2UL, 0x6938502fUL, 0x0c5fec97UL, 0xe2f05985UL, 0x8797e53dUL,
+    0xd1878665UL, 0xb4e03addUL, 0x5a4f8fcfUL, 0x3f283377UL, 0x8610e4eaUL,
+    0xe3775852UL, 0x0dd8ed40UL, 0x68bf51f8UL, 0xa1f82bf0UL, 0xc49f9748UL,
+    0x2a30225aUL, 0x4f579ee2UL, 0xf66f497fUL, 0x9308f5c7UL, 0x7da740d5UL,
+    0x18c0fc6dUL, 0x4ed09f35UL, 0x2bb7238dUL, 0xc518969fUL, 0xa07f2a27UL,
+    0x1947fdbaUL, 0x7c204102UL, 0x928ff410UL, 0xf7e848a8UL, 0x3d58149bUL,
+    0x583fa823UL, 0xb6901d31UL, 0xd3f7a189UL, 0x6acf7614UL, 0x0fa8caacUL,
+    0xe1077fbeUL, 0x8460c306UL, 0xd270a05eUL, 0xb7171ce6UL, 0x59b8a9f4UL,
+    0x3cdf154cUL, 0x85e7c2d1UL, 0xe0807e69UL, 0x0e2fcb7bUL, 0x6b4877c3UL,
+    0xa20f0dcbUL, 0xc768b173UL, 0x29c70461UL, 0x4ca0b8d9UL, 0xf5986f44UL,
+    0x90ffd3fcUL, 0x7e5066eeUL, 0x1b37da56UL, 0x4d27b90eUL, 0x284005b6UL,
+    0xc6efb0a4UL, 0xa3880c1cUL, 0x1ab0db81UL, 0x7fd76739UL, 0x9178d22bUL,
+    0xf41f6e93UL, 0x03f7263bUL, 0x66909a83UL, 0x883f2f91UL, 0xed589329UL,
+    0x546044b4UL, 0x3107f80cUL, 0xdfa84d1eUL, 0xbacff1a6UL, 0xecdf92feUL,
+    0x89b82e46UL, 0x67179b54UL, 0x027027ecUL, 0xbb48f071UL, 0xde2f4cc9UL,
+    0x3080f9dbUL, 0x55e74563UL, 0x9ca03f6bUL, 0xf9c783d3UL, 0x176836c1UL,
+    0x720f8a79UL, 0xcb375de4UL, 0xae50e15cUL, 0x40ff544eUL, 0x2598e8f6UL,
+    0x73888baeUL, 0x16ef3716UL, 0xf8408204UL, 0x9d273ebcUL, 0x241fe921UL,
+    0x41785599UL, 0xafd7e08bUL, 0xcab05c33UL, 0x3bb659edUL, 0x5ed1e555UL,
+    0xb07e5047UL, 0xd519ecffUL, 0x6c213b62UL, 0x094687daUL, 0xe7e932c8UL,
+    0x828e8e70UL, 0xd49eed28UL, 0xb1f95190UL, 0x5f56e482UL, 0x3a31583aUL,
+    0x83098fa7UL, 0xe66e331fUL, 0x08c1860dUL, 0x6da63ab5UL, 0xa4e140bdUL,
+    0xc186fc05UL, 0x2f294917UL, 0x4a4ef5afUL, 0xf3762232UL, 0x96119e8aUL,
+    0x78be2b98UL, 0x1dd99720UL, 0x4bc9f478UL, 0x2eae48c0UL, 0xc001fdd2UL,
+    0xa566416aUL, 0x1c5e96f7UL, 0x79392a4fUL, 0x97969f5dUL, 0xf2f123e5UL,
+    0x05196b4dUL, 0x607ed7f5UL, 0x8ed162e7UL, 0xebb6de5fUL, 0x528e09c2UL,
+    0x37e9b57aUL, 0xd9460068UL, 0xbc21bcd0UL, 0xea31df88UL, 0x8f566330UL,
+    0x61f9d622UL, 0x049e6a9aUL, 0xbda6bd07UL, 0xd8c101bfUL, 0x366eb4adUL,
+    0x53090815UL, 0x9a4e721dUL, 0xff29cea5UL, 0x11867bb7UL, 0x74e1c70fUL,
+    0xcdd91092UL, 0xa8beac2aUL, 0x46111938UL, 0x2376a580UL, 0x7566c6d8UL,
+    0x10017a60UL, 0xfeaecf72UL, 0x9bc973caUL, 0x22f1a457UL, 0x479618efUL,
+    0xa939adfdUL, 0xcc5e1145UL, 0x06ee4d76UL, 0x6389f1ceUL, 0x8d2644dcUL,
+    0xe841f864UL, 0x51792ff9UL, 0x341e9341UL, 0xdab12653UL, 0xbfd69aebUL,
+    0xe9c6f9b3UL, 0x8ca1450bUL, 0x620ef019UL, 0x07694ca1UL, 0xbe519b3cUL,
+    0xdb362784UL, 0x35999296UL, 0x50fe2e2eUL, 0x99b95426UL, 0xfcdee89eUL,
+    0x12715d8cUL, 0x7716e134UL, 0xce2e36a9UL, 0xab498a11UL, 0x45e63f03UL,
+    0x208183bbUL, 0x7691e0e3UL, 0x13f65c5bUL, 0xfd59e949UL, 0x983e55f1UL,
+    0x2106826cUL, 0x44613ed4UL, 0xaace8bc6UL, 0xcfa9377eUL, 0x38417fd6UL,
+    0x5d26c36eUL, 0xb389767cUL, 0xd6eecac4UL, 0x6fd61d59UL, 0x0ab1a1e1UL,
+    0xe41e14f3UL, 0x8179a84bUL, 0xd769cb13UL, 0xb20e77abUL, 0x5ca1c2b9UL,
+    0x39c67e01UL, 0x80fea99cUL, 0xe5991524UL, 0x0b36a036UL, 0x6e511c8eUL,
+    0xa7166686UL, 0xc271da3eUL, 0x2cde6f2cUL, 0x49b9d394UL, 0xf0810409UL,
+    0x95e6b8b1UL, 0x7b490da3UL, 0x1e2eb11bUL, 0x483ed243UL, 0x2d596efbUL,
+    0xc3f6dbe9UL, 0xa6916751UL, 0x1fa9b0ccUL, 0x7ace0c74UL, 0x9461b966UL,
+    0xf10605deUL
+#endif
+  }
+};
diff --git a/xs/src/png/zlib/deflate.c b/xs/src/png/zlib/deflate.c
new file mode 100644
index 000000000..1ec761448
--- /dev/null
+++ b/xs/src/png/zlib/deflate.c
@@ -0,0 +1,2163 @@
+/* deflate.c -- compress data using the deflation algorithm
+ * Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process depends on being able to identify portions
+ *      of the input text which are identical to earlier input (within a
+ *      sliding window trailing behind the input currently being processed).
+ *
+ *      The most straightforward technique turns out to be the fastest for
+ *      most input files: try all possible matches and select the longest.
+ *      The key feature of this algorithm is that insertions into the string
+ *      dictionary are very simple and thus fast, and deletions are avoided
+ *      completely. Insertions are performed at each input character, whereas
+ *      string matches are performed only when the previous match ends. So it
+ *      is preferable to spend more time in matches to allow very fast string
+ *      insertions and avoid deletions. The matching algorithm for small
+ *      strings is inspired from that of Rabin & Karp. A brute force approach
+ *      is used to find longer strings when a small match has been found.
+ *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
+ *      (by Leonid Broukhis).
+ *         A previous version of this file used a more sophisticated algorithm
+ *      (by Fiala and Greene) which is guaranteed to run in linear amortized
+ *      time, but has a larger average cost, uses more memory and is patented.
+ *      However the F&G algorithm may be faster for some highly redundant
+ *      files if the parameter max_chain_length (described below) is too large.
+ *
+ *  ACKNOWLEDGEMENTS
+ *
+ *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
+ *      I found it in 'freeze' written by Leonid Broukhis.
+ *      Thanks to many people for bug reports and testing.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
+ *      Available in http://tools.ietf.org/html/rfc1951
+ *
+ *      A description of the Rabin and Karp algorithm is given in the book
+ *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
+ *
+ *      Fiala,E.R., and Greene,D.H.
+ *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
+ *
+ */
+
+/* @(#) $Id$ */
+
+#include "deflate.h"
+
+const char deflate_copyright[] =
+   " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/* ===========================================================================
+ *  Function prototypes.
+ */
+typedef enum {
+    need_more,      /* block not completed, need more input or more output */
+    block_done,     /* block flush performed */
+    finish_started, /* finish started, need only more output at next deflate */
+    finish_done     /* finish done, accept no more input or output */
+} block_state;
+
+typedef block_state (*compress_func) OF((deflate_state *s, int flush));
+/* Compression function. Returns the block state after the call. */
+
+local int deflateStateCheck      OF((z_streamp strm));
+local void slide_hash     OF((deflate_state *s));
+local void fill_window    OF((deflate_state *s));
+local block_state deflate_stored OF((deflate_state *s, int flush));
+local block_state deflate_fast   OF((deflate_state *s, int flush));
+#ifndef FASTEST
+local block_state deflate_slow   OF((deflate_state *s, int flush));
+#endif
+local block_state deflate_rle    OF((deflate_state *s, int flush));
+local block_state deflate_huff   OF((deflate_state *s, int flush));
+local void lm_init        OF((deflate_state *s));
+local void putShortMSB    OF((deflate_state *s, uInt b));
+local void flush_pending  OF((z_streamp strm));
+local unsigned read_buf   OF((z_streamp strm, Bytef *buf, unsigned size));
+#ifdef ASMV
+#  pragma message("Assembler code may have bugs -- use at your own risk")
+      void match_init OF((void)); /* asm code initialization */
+      uInt longest_match  OF((deflate_state *s, IPos cur_match));
+#else
+local uInt longest_match  OF((deflate_state *s, IPos cur_match));
+#endif
+
+#ifdef ZLIB_DEBUG
+local  void check_match OF((deflate_state *s, IPos start, IPos match,
+                            int length));
+#endif
+
+/* ===========================================================================
+ * Local data
+ */
+
+#define NIL 0
+/* Tail of hash chains */
+
+#ifndef TOO_FAR
+#  define TOO_FAR 4096
+#endif
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
+
+/* Values for max_lazy_match, good_match and max_chain_length, depending on
+ * the desired pack level (0..9). The values given below have been tuned to
+ * exclude worst case performance for pathological files. Better values may be
+ * found for specific files.
+ */
+typedef struct config_s {
+   ush good_length; /* reduce lazy search above this match length */
+   ush max_lazy;    /* do not perform lazy search above this match length */
+   ush nice_length; /* quit search above this match length */
+   ush max_chain;
+   compress_func func;
+} config;
+
+#ifdef FASTEST
+local const config configuration_table[2] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
+/* 1 */ {4,    4,  8,    4, deflate_fast}}; /* max speed, no lazy matches */
+#else
+local const config configuration_table[10] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
+/* 1 */ {4,    4,  8,    4, deflate_fast}, /* max speed, no lazy matches */
+/* 2 */ {4,    5, 16,    8, deflate_fast},
+/* 3 */ {4,    6, 32,   32, deflate_fast},
+
+/* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
+/* 5 */ {8,   16, 32,   32, deflate_slow},
+/* 6 */ {8,   16, 128, 128, deflate_slow},
+/* 7 */ {8,   32, 128, 256, deflate_slow},
+/* 8 */ {32, 128, 258, 1024, deflate_slow},
+/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
+#endif
+
+/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
+ * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
+ * meaning.
+ */
+
+/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
+#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
+
+/* ===========================================================================
+ * Update a hash value with the given input byte
+ * IN  assertion: all calls to UPDATE_HASH are made with consecutive input
+ *    characters, so that a running hash key can be computed from the previous
+ *    key instead of complete recalculation each time.
+ */
+#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
+
+
+/* ===========================================================================
+ * Insert string str in the dictionary and set match_head to the previous head
+ * of the hash chain (the most recent string with same hash key). Return
+ * the previous length of the hash chain.
+ * If this file is compiled with -DFASTEST, the compression level is forced
+ * to 1, and no hash chains are maintained.
+ * IN  assertion: all calls to INSERT_STRING are made with consecutive input
+ *    characters and the first MIN_MATCH bytes of str are valid (except for
+ *    the last MIN_MATCH-1 bytes of the input file).
+ */
+#ifdef FASTEST
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#else
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#endif
+
+/* ===========================================================================
+ * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
+ * prev[] will be initialized on the fly.
+ */
+#define CLEAR_HASH(s) \
+    s->head[s->hash_size-1] = NIL; \
+    zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
+
+/* ===========================================================================
+ * Slide the hash table when sliding the window down (could be avoided with 32
+ * bit values at the expense of memory usage). We slide even when level == 0 to
+ * keep the hash table consistent if we switch back to level > 0 later.
+ */
+local void slide_hash(s)
+    deflate_state *s;
+{
+    unsigned n, m;
+    Posf *p;
+    uInt wsize = s->w_size;
+
+    n = s->hash_size;
+    p = &s->head[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+    } while (--n);
+    n = wsize;
+#ifndef FASTEST
+    p = &s->prev[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+        /* If n is not on any hash chain, prev[n] is garbage but
+         * its value will never be used.
+         */
+    } while (--n);
+#endif
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateInit_(strm, level, version, stream_size)
+    z_streamp strm;
+    int level;
+    const char *version;
+    int stream_size;
+{
+    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
+                         Z_DEFAULT_STRATEGY, version, stream_size);
+    /* To do: ignore strm->next_in if we use it as window */
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
+                  version, stream_size)
+    z_streamp strm;
+    int  level;
+    int  method;
+    int  windowBits;
+    int  memLevel;
+    int  strategy;
+    const char *version;
+    int stream_size;
+{
+    deflate_state *s;
+    int wrap = 1;
+    static const char my_version[] = ZLIB_VERSION;
+
+    ushf *overlay;
+    /* We overlay pending_buf and d_buf+l_buf. This works since the average
+     * output size for (length,distance) codes is <= 24 bits.
+     */
+
+    if (version == Z_NULL || version[0] != my_version[0] ||
+        stream_size != sizeof(z_stream)) {
+        return Z_VERSION_ERROR;
+    }
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+
+    strm->msg = Z_NULL;
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zfree = zcfree;
+#endif
+
+#ifdef FASTEST
+    if (level != 0) level = 1;
+#else
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#endif
+
+    if (windowBits < 0) { /* suppress zlib wrapper */
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+#ifdef GZIP
+    else if (windowBits > 15) {
+        wrap = 2;       /* write gzip wrapper instead */
+        windowBits -= 16;
+    }
+#endif
+    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
+        windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
+        strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
+        return Z_STREAM_ERROR;
+    }
+    if (windowBits == 8) windowBits = 9;  /* until 256-byte window bug fixed */
+    s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
+    if (s == Z_NULL) return Z_MEM_ERROR;
+    strm->state = (struct internal_state FAR *)s;
+    s->strm = strm;
+    s->status = INIT_STATE;     /* to pass state test in deflateReset() */
+
+    s->wrap = wrap;
+    s->gzhead = Z_NULL;
+    s->w_bits = (uInt)windowBits;
+    s->w_size = 1 << s->w_bits;
+    s->w_mask = s->w_size - 1;
+
+    s->hash_bits = (uInt)memLevel + 7;
+    s->hash_size = 1 << s->hash_bits;
+    s->hash_mask = s->hash_size - 1;
+    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
+
+    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
+    s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
+    s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
+
+    s->high_water = 0;      /* nothing written to s->window yet */
+
+    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
+
+    overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
+    s->pending_buf = (uchf *) overlay;
+    s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
+
+    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
+        s->pending_buf == Z_NULL) {
+        s->status = FINISH_STATE;
+        strm->msg = ERR_MSG(Z_MEM_ERROR);
+        deflateEnd (strm);
+        return Z_MEM_ERROR;
+    }
+    s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
+    s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
+
+    s->level = level;
+    s->strategy = strategy;
+    s->method = (Byte)method;
+
+    return deflateReset(strm);
+}
+
+/* =========================================================================
+ * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
+ */
+local int deflateStateCheck (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    s = strm->state;
+    if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
+#ifdef GZIP
+                                           s->status != GZIP_STATE &&
+#endif
+                                           s->status != EXTRA_STATE &&
+                                           s->status != NAME_STATE &&
+                                           s->status != COMMENT_STATE &&
+                                           s->status != HCRC_STATE &&
+                                           s->status != BUSY_STATE &&
+                                           s->status != FINISH_STATE))
+        return 1;
+    return 0;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    const Bytef *dictionary;
+    uInt  dictLength;
+{
+    deflate_state *s;
+    uInt str, n;
+    int wrap;
+    unsigned avail;
+    z_const unsigned char *next;
+
+    if (deflateStateCheck(strm) || dictionary == Z_NULL)
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    wrap = s->wrap;
+    if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
+        return Z_STREAM_ERROR;
+
+    /* when using zlib wrappers, compute Adler-32 for provided dictionary */
+    if (wrap == 1)
+        strm->adler = adler32(strm->adler, dictionary, dictLength);
+    s->wrap = 0;                    /* avoid computing Adler-32 in read_buf */
+
+    /* if dictionary would fill window, just replace the history */
+    if (dictLength >= s->w_size) {
+        if (wrap == 0) {            /* already empty otherwise */
+            CLEAR_HASH(s);
+            s->strstart = 0;
+            s->block_start = 0L;
+            s->insert = 0;
+        }
+        dictionary += dictLength - s->w_size;  /* use the tail */
+        dictLength = s->w_size;
+    }
+
+    /* insert dictionary into window and hash */
+    avail = strm->avail_in;
+    next = strm->next_in;
+    strm->avail_in = dictLength;
+    strm->next_in = (z_const Bytef *)dictionary;
+    fill_window(s);
+    while (s->lookahead >= MIN_MATCH) {
+        str = s->strstart;
+        n = s->lookahead - (MIN_MATCH-1);
+        do {
+            UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
+#ifndef FASTEST
+            s->prev[str & s->w_mask] = s->head[s->ins_h];
+#endif
+            s->head[s->ins_h] = (Pos)str;
+            str++;
+        } while (--n);
+        s->strstart = str;
+        s->lookahead = MIN_MATCH-1;
+        fill_window(s);
+    }
+    s->strstart += s->lookahead;
+    s->block_start = (long)s->strstart;
+    s->insert = s->lookahead;
+    s->lookahead = 0;
+    s->match_length = s->prev_length = MIN_MATCH-1;
+    s->match_available = 0;
+    strm->next_in = next;
+    strm->avail_in = avail;
+    s->wrap = wrap;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    Bytef *dictionary;
+    uInt  *dictLength;
+{
+    deflate_state *s;
+    uInt len;
+
+    if (deflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    len = s->strstart + s->lookahead;
+    if (len > s->w_size)
+        len = s->w_size;
+    if (dictionary != Z_NULL && len)
+        zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
+    if (dictLength != Z_NULL)
+        *dictLength = len;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateResetKeep (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+
+    if (deflateStateCheck(strm)) {
+        return Z_STREAM_ERROR;
+    }
+
+    strm->total_in = strm->total_out = 0;
+    strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
+    strm->data_type = Z_UNKNOWN;
+
+    s = (deflate_state *)strm->state;
+    s->pending = 0;
+    s->pending_out = s->pending_buf;
+
+    if (s->wrap < 0) {
+        s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
+    }
+    s->status =
+#ifdef GZIP
+        s->wrap == 2 ? GZIP_STATE :
+#endif
+        s->wrap ? INIT_STATE : BUSY_STATE;
+    strm->adler =
+#ifdef GZIP
+        s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
+#endif
+        adler32(0L, Z_NULL, 0);
+    s->last_flush = Z_NO_FLUSH;
+
+    _tr_init(s);
+
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateReset (strm)
+    z_streamp strm;
+{
+    int ret;
+
+    ret = deflateResetKeep(strm);
+    if (ret == Z_OK)
+        lm_init(strm->state);
+    return ret;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateSetHeader (strm, head)
+    z_streamp strm;
+    gz_headerp head;
+{
+    if (deflateStateCheck(strm) || strm->state->wrap != 2)
+        return Z_STREAM_ERROR;
+    strm->state->gzhead = head;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflatePending (strm, pending, bits)
+    unsigned *pending;
+    int *bits;
+    z_streamp strm;
+{
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    if (pending != Z_NULL)
+        *pending = strm->state->pending;
+    if (bits != Z_NULL)
+        *bits = strm->state->bi_valid;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflatePrime (strm, bits, value)
+    z_streamp strm;
+    int bits;
+    int value;
+{
+    deflate_state *s;
+    int put;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+    if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
+        return Z_BUF_ERROR;
+    do {
+        put = Buf_size - s->bi_valid;
+        if (put > bits)
+            put = bits;
+        s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
+        s->bi_valid += put;
+        _tr_flush_bits(s);
+        value >>= put;
+        bits -= put;
+    } while (bits);
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateParams(strm, level, strategy)
+    z_streamp strm;
+    int level;
+    int strategy;
+{
+    deflate_state *s;
+    compress_func func;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+
+#ifdef FASTEST
+    if (level != 0) level = 1;
+#else
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#endif
+    if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
+        return Z_STREAM_ERROR;
+    }
+    func = configuration_table[s->level].func;
+
+    if ((strategy != s->strategy || func != configuration_table[level].func) &&
+        s->high_water) {
+        /* Flush the last buffer: */
+        int err = deflate(strm, Z_BLOCK);
+        if (err == Z_STREAM_ERROR)
+            return err;
+        if (strm->avail_out == 0)
+            return Z_BUF_ERROR;
+    }
+    if (s->level != level) {
+        if (s->level == 0 && s->matches != 0) {
+            if (s->matches == 1)
+                slide_hash(s);
+            else
+                CLEAR_HASH(s);
+            s->matches = 0;
+        }
+        s->level = level;
+        s->max_lazy_match   = configuration_table[level].max_lazy;
+        s->good_match       = configuration_table[level].good_length;
+        s->nice_match       = configuration_table[level].nice_length;
+        s->max_chain_length = configuration_table[level].max_chain;
+    }
+    s->strategy = strategy;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
+    z_streamp strm;
+    int good_length;
+    int max_lazy;
+    int nice_length;
+    int max_chain;
+{
+    deflate_state *s;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+    s->good_match = (uInt)good_length;
+    s->max_lazy_match = (uInt)max_lazy;
+    s->nice_match = nice_length;
+    s->max_chain_length = (uInt)max_chain;
+    return Z_OK;
+}
+
+/* =========================================================================
+ * For the default windowBits of 15 and memLevel of 8, this function returns
+ * a close to exact, as well as small, upper bound on the compressed size.
+ * They are coded as constants here for a reason--if the #define's are
+ * changed, then this function needs to be changed as well.  The return
+ * value for 15 and 8 only works for those exact settings.
+ *
+ * For any setting other than those defaults for windowBits and memLevel,
+ * the value returned is a conservative worst case for the maximum expansion
+ * resulting from using fixed blocks instead of stored blocks, which deflate
+ * can emit on compressed data for some combinations of the parameters.
+ *
+ * This function could be more sophisticated to provide closer upper bounds for
+ * every combination of windowBits and memLevel.  But even the conservative
+ * upper bound of about 14% expansion does not seem onerous for output buffer
+ * allocation.
+ */
+uLong ZEXPORT deflateBound(strm, sourceLen)
+    z_streamp strm;
+    uLong sourceLen;
+{
+    deflate_state *s;
+    uLong complen, wraplen;
+
+    /* conservative upper bound for compressed data */
+    complen = sourceLen +
+              ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
+
+    /* if can't get parameters, return conservative bound plus zlib wrapper */
+    if (deflateStateCheck(strm))
+        return complen + 6;
+
+    /* compute wrapper length */
+    s = strm->state;
+    switch (s->wrap) {
+    case 0:                                 /* raw deflate */
+        wraplen = 0;
+        break;
+    case 1:                                 /* zlib wrapper */
+        wraplen = 6 + (s->strstart ? 4 : 0);
+        break;
+#ifdef GZIP
+    case 2:                                 /* gzip wrapper */
+        wraplen = 18;
+        if (s->gzhead != Z_NULL) {          /* user-supplied gzip header */
+            Bytef *str;
+            if (s->gzhead->extra != Z_NULL)
+                wraplen += 2 + s->gzhead->extra_len;
+            str = s->gzhead->name;
+            if (str != Z_NULL)
+                do {
+                    wraplen++;
+                } while (*str++);
+            str = s->gzhead->comment;
+            if (str != Z_NULL)
+                do {
+                    wraplen++;
+                } while (*str++);
+            if (s->gzhead->hcrc)
+                wraplen += 2;
+        }
+        break;
+#endif
+    default:                                /* for compiler happiness */
+        wraplen = 6;
+    }
+
+    /* if not default parameters, return conservative bound */
+    if (s->w_bits != 15 || s->hash_bits != 8 + 7)
+        return complen + wraplen;
+
+    /* default settings: return tight bound for that case */
+    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
+           (sourceLen >> 25) + 13 - 6 + wraplen;
+}
+
+/* =========================================================================
+ * Put a short in the pending buffer. The 16-bit value is put in MSB order.
+ * IN assertion: the stream state is correct and there is enough room in
+ * pending_buf.
+ */
+local void putShortMSB (s, b)
+    deflate_state *s;
+    uInt b;
+{
+    put_byte(s, (Byte)(b >> 8));
+    put_byte(s, (Byte)(b & 0xff));
+}
+
+/* =========================================================================
+ * Flush as much pending output as possible. All deflate() output, except for
+ * some deflate_stored() output, goes through this function so some
+ * applications may wish to modify it to avoid allocating a large
+ * strm->next_out buffer and copying into it. (See also read_buf()).
+ */
+local void flush_pending(strm)
+    z_streamp strm;
+{
+    unsigned len;
+    deflate_state *s = strm->state;
+
+    _tr_flush_bits(s);
+    len = s->pending;
+    if (len > strm->avail_out) len = strm->avail_out;
+    if (len == 0) return;
+
+    zmemcpy(strm->next_out, s->pending_out, len);
+    strm->next_out  += len;
+    s->pending_out  += len;
+    strm->total_out += len;
+    strm->avail_out -= len;
+    s->pending      -= len;
+    if (s->pending == 0) {
+        s->pending_out = s->pending_buf;
+    }
+}
+
+/* ===========================================================================
+ * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
+ */
+#define HCRC_UPDATE(beg) \
+    do { \
+        if (s->gzhead->hcrc && s->pending > (beg)) \
+            strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
+                                s->pending - (beg)); \
+    } while (0)
+
+/* ========================================================================= */
+int ZEXPORT deflate (strm, flush)
+    z_streamp strm;
+    int flush;
+{
+    int old_flush; /* value of flush param for previous deflate call */
+    deflate_state *s;
+
+    if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
+        return Z_STREAM_ERROR;
+    }
+    s = strm->state;
+
+    if (strm->next_out == Z_NULL ||
+        (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
+        (s->status == FINISH_STATE && flush != Z_FINISH)) {
+        ERR_RETURN(strm, Z_STREAM_ERROR);
+    }
+    if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
+
+    old_flush = s->last_flush;
+    s->last_flush = flush;
+
+    /* Flush as much pending output as possible */
+    if (s->pending != 0) {
+        flush_pending(strm);
+        if (strm->avail_out == 0) {
+            /* Since avail_out is 0, deflate will be called again with
+             * more output space, but possibly with both pending and
+             * avail_in equal to zero. There won't be anything to do,
+             * but this is not an error situation so make sure we
+             * return OK instead of BUF_ERROR at next call of deflate:
+             */
+            s->last_flush = -1;
+            return Z_OK;
+        }
+
+    /* Make sure there is something to do and avoid duplicate consecutive
+     * flushes. For repeated and useless calls with Z_FINISH, we keep
+     * returning Z_STREAM_END instead of Z_BUF_ERROR.
+     */
+    } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
+               flush != Z_FINISH) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* User must not provide more input after the first FINISH: */
+    if (s->status == FINISH_STATE && strm->avail_in != 0) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* Write the header */
+    if (s->status == INIT_STATE) {
+        /* zlib header */
+        uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
+        uInt level_flags;
+
+        if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
+            level_flags = 0;
+        else if (s->level < 6)
+            level_flags = 1;
+        else if (s->level == 6)
+            level_flags = 2;
+        else
+            level_flags = 3;
+        header |= (level_flags << 6);
+        if (s->strstart != 0) header |= PRESET_DICT;
+        header += 31 - (header % 31);
+
+        putShortMSB(s, header);
+
+        /* Save the adler32 of the preset dictionary: */
+        if (s->strstart != 0) {
+            putShortMSB(s, (uInt)(strm->adler >> 16));
+            putShortMSB(s, (uInt)(strm->adler & 0xffff));
+        }
+        strm->adler = adler32(0L, Z_NULL, 0);
+        s->status = BUSY_STATE;
+
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#ifdef GZIP
+    if (s->status == GZIP_STATE) {
+        /* gzip header */
+        strm->adler = crc32(0L, Z_NULL, 0);
+        put_byte(s, 31);
+        put_byte(s, 139);
+        put_byte(s, 8);
+        if (s->gzhead == Z_NULL) {
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, OS_CODE);
+            s->status = BUSY_STATE;
+
+            /* Compression must start with an empty pending buffer */
+            flush_pending(strm);
+            if (s->pending != 0) {
+                s->last_flush = -1;
+                return Z_OK;
+            }
+        }
+        else {
+            put_byte(s, (s->gzhead->text ? 1 : 0) +
+                     (s->gzhead->hcrc ? 2 : 0) +
+                     (s->gzhead->extra == Z_NULL ? 0 : 4) +
+                     (s->gzhead->name == Z_NULL ? 0 : 8) +
+                     (s->gzhead->comment == Z_NULL ? 0 : 16)
+                     );
+            put_byte(s, (Byte)(s->gzhead->time & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, s->gzhead->os & 0xff);
+            if (s->gzhead->extra != Z_NULL) {
+                put_byte(s, s->gzhead->extra_len & 0xff);
+                put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
+            }
+            if (s->gzhead->hcrc)
+                strm->adler = crc32(strm->adler, s->pending_buf,
+                                    s->pending);
+            s->gzindex = 0;
+            s->status = EXTRA_STATE;
+        }
+    }
+    if (s->status == EXTRA_STATE) {
+        if (s->gzhead->extra != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
+            while (s->pending + left > s->pending_buf_size) {
+                uInt copy = s->pending_buf_size - s->pending;
+                zmemcpy(s->pending_buf + s->pending,
+                        s->gzhead->extra + s->gzindex, copy);
+                s->pending = s->pending_buf_size;
+                HCRC_UPDATE(beg);
+                s->gzindex += copy;
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
+                beg = 0;
+                left -= copy;
+            }
+            zmemcpy(s->pending_buf + s->pending,
+                    s->gzhead->extra + s->gzindex, left);
+            s->pending += left;
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
+        }
+        s->status = NAME_STATE;
+    }
+    if (s->status == NAME_STATE) {
+        if (s->gzhead->name != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            int val;
+            do {
+                if (s->pending == s->pending_buf_size) {
+                    HCRC_UPDATE(beg);
+                    flush_pending(strm);
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
+                    }
+                    beg = 0;
+                }
+                val = s->gzhead->name[s->gzindex++];
+                put_byte(s, val);
+            } while (val != 0);
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
+        }
+        s->status = COMMENT_STATE;
+    }
+    if (s->status == COMMENT_STATE) {
+        if (s->gzhead->comment != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            int val;
+            do {
+                if (s->pending == s->pending_buf_size) {
+                    HCRC_UPDATE(beg);
+                    flush_pending(strm);
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
+                    }
+                    beg = 0;
+                }
+                val = s->gzhead->comment[s->gzindex++];
+                put_byte(s, val);
+            } while (val != 0);
+            HCRC_UPDATE(beg);
+        }
+        s->status = HCRC_STATE;
+    }
+    if (s->status == HCRC_STATE) {
+        if (s->gzhead->hcrc) {
+            if (s->pending + 2 > s->pending_buf_size) {
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
+            }
+            put_byte(s, (Byte)(strm->adler & 0xff));
+            put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+            strm->adler = crc32(0L, Z_NULL, 0);
+        }
+        s->status = BUSY_STATE;
+
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#endif
+
+    /* Start a new block or continue the current one.
+     */
+    if (strm->avail_in != 0 || s->lookahead != 0 ||
+        (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
+        block_state bstate;
+
+        bstate = s->level == 0 ? deflate_stored(s, flush) :
+                 s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
+                 s->strategy == Z_RLE ? deflate_rle(s, flush) :
+                 (*(configuration_table[s->level].func))(s, flush);
+
+        if (bstate == finish_started || bstate == finish_done) {
+            s->status = FINISH_STATE;
+        }
+        if (bstate == need_more || bstate == finish_started) {
+            if (strm->avail_out == 0) {
+                s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
+            }
+            return Z_OK;
+            /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
+             * of deflate should use the same flush parameter to make sure
+             * that the flush is complete. So we don't have to output an
+             * empty block here, this will be done at next call. This also
+             * ensures that for a very small output buffer, we emit at most
+             * one empty block.
+             */
+        }
+        if (bstate == block_done) {
+            if (flush == Z_PARTIAL_FLUSH) {
+                _tr_align(s);
+            } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
+                _tr_stored_block(s, (char*)0, 0L, 0);
+                /* For a full flush, this empty block will be recognized
+                 * as a special marker by inflate_sync().
+                 */
+                if (flush == Z_FULL_FLUSH) {
+                    CLEAR_HASH(s);             /* forget history */
+                    if (s->lookahead == 0) {
+                        s->strstart = 0;
+                        s->block_start = 0L;
+                        s->insert = 0;
+                    }
+                }
+            }
+            flush_pending(strm);
+            if (strm->avail_out == 0) {
+              s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
+              return Z_OK;
+            }
+        }
+    }
+
+    if (flush != Z_FINISH) return Z_OK;
+    if (s->wrap <= 0) return Z_STREAM_END;
+
+    /* Write the trailer */
+#ifdef GZIP
+    if (s->wrap == 2) {
+        put_byte(s, (Byte)(strm->adler & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
+        put_byte(s, (Byte)(strm->total_in & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
+    }
+    else
+#endif
+    {
+        putShortMSB(s, (uInt)(strm->adler >> 16));
+        putShortMSB(s, (uInt)(strm->adler & 0xffff));
+    }
+    flush_pending(strm);
+    /* If avail_out is zero, the application will call deflate again
+     * to flush the rest.
+     */
+    if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
+    return s->pending != 0 ? Z_OK : Z_STREAM_END;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateEnd (strm)
+    z_streamp strm;
+{
+    int status;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+
+    status = strm->state->status;
+
+    /* Deallocate in reverse order of allocations: */
+    TRY_FREE(strm, strm->state->pending_buf);
+    TRY_FREE(strm, strm->state->head);
+    TRY_FREE(strm, strm->state->prev);
+    TRY_FREE(strm, strm->state->window);
+
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+
+    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
+}
+
+/* =========================================================================
+ * Copy the source state to the destination state.
+ * To simplify the source, this is not supported for 16-bit MSDOS (which
+ * doesn't have enough memory anyway to duplicate compression states).
+ */
+int ZEXPORT deflateCopy (dest, source)
+    z_streamp dest;
+    z_streamp source;
+{
+#ifdef MAXSEG_64K
+    return Z_STREAM_ERROR;
+#else
+    deflate_state *ds;
+    deflate_state *ss;
+    ushf *overlay;
+
+
+    if (deflateStateCheck(source) || dest == Z_NULL) {
+        return Z_STREAM_ERROR;
+    }
+
+    ss = source->state;
+
+    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+
+    ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
+    if (ds == Z_NULL) return Z_MEM_ERROR;
+    dest->state = (struct internal_state FAR *) ds;
+    zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
+    ds->strm = dest;
+
+    ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
+    ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
+    ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
+    overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
+    ds->pending_buf = (uchf *) overlay;
+
+    if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
+        ds->pending_buf == Z_NULL) {
+        deflateEnd (dest);
+        return Z_MEM_ERROR;
+    }
+    /* following zmemcpy do not work for 16-bit MSDOS */
+    zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
+    zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
+    zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
+    zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
+
+    ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
+    ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
+    ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
+
+    ds->l_desc.dyn_tree = ds->dyn_ltree;
+    ds->d_desc.dyn_tree = ds->dyn_dtree;
+    ds->bl_desc.dyn_tree = ds->bl_tree;
+
+    return Z_OK;
+#endif /* MAXSEG_64K */
+}
+
+/* ===========================================================================
+ * Read a new buffer from the current input stream, update the adler32
+ * and total number of bytes read.  All deflate() input goes through
+ * this function so some applications may wish to modify it to avoid
+ * allocating a large strm->next_in buffer and copying from it.
+ * (See also flush_pending()).
+ */
+local unsigned read_buf(strm, buf, size)
+    z_streamp strm;
+    Bytef *buf;
+    unsigned size;
+{
+    unsigned len = strm->avail_in;
+
+    if (len > size) len = size;
+    if (len == 0) return 0;
+
+    strm->avail_in  -= len;
+
+    zmemcpy(buf, strm->next_in, len);
+    if (strm->state->wrap == 1) {
+        strm->adler = adler32(strm->adler, buf, len);
+    }
+#ifdef GZIP
+    else if (strm->state->wrap == 2) {
+        strm->adler = crc32(strm->adler, buf, len);
+    }
+#endif
+    strm->next_in  += len;
+    strm->total_in += len;
+
+    return len;
+}
+
+/* ===========================================================================
+ * Initialize the "longest match" routines for a new zlib stream
+ */
+local void lm_init (s)
+    deflate_state *s;
+{
+    s->window_size = (ulg)2L*s->w_size;
+
+    CLEAR_HASH(s);
+
+    /* Set the default configuration parameters:
+     */
+    s->max_lazy_match   = configuration_table[s->level].max_lazy;
+    s->good_match       = configuration_table[s->level].good_length;
+    s->nice_match       = configuration_table[s->level].nice_length;
+    s->max_chain_length = configuration_table[s->level].max_chain;
+
+    s->strstart = 0;
+    s->block_start = 0L;
+    s->lookahead = 0;
+    s->insert = 0;
+    s->match_length = s->prev_length = MIN_MATCH-1;
+    s->match_available = 0;
+    s->ins_h = 0;
+#ifndef FASTEST
+#ifdef ASMV
+    match_init(); /* initialize the asm code */
+#endif
+#endif
+}
+
+#ifndef FASTEST
+/* ===========================================================================
+ * Set match_start to the longest match starting at the given string and
+ * return its length. Matches shorter or equal to prev_length are discarded,
+ * in which case the result is equal to prev_length and match_start is
+ * garbage.
+ * IN assertions: cur_match is the head of the hash chain for the current
+ *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
+ * OUT assertion: the match length is not greater than s->lookahead.
+ */
+#ifndef ASMV
+/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
+ * match.S. The code will be functionally equivalent.
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    unsigned chain_length = s->max_chain_length;/* max hash chain length */
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                      /* matched string */
+    register int len;                           /* length of current match */
+    int best_len = (int)s->prev_length;         /* best match length so far */
+    int nice_match = s->nice_match;             /* stop if match long enough */
+    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+        s->strstart - (IPos)MAX_DIST(s) : NIL;
+    /* Stop when cur_match becomes <= limit. To simplify the code,
+     * we prevent matches with the string of window index 0.
+     */
+    Posf *prev = s->prev;
+    uInt wmask = s->w_mask;
+
+#ifdef UNALIGNED_OK
+    /* Compare two bytes at a time. Note: this is not always beneficial.
+     * Try with and without -DUNALIGNED_OK to check.
+     */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
+    register ush scan_start = *(ushf*)scan;
+    register ush scan_end   = *(ushf*)(scan+best_len-1);
+#else
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+    register Byte scan_end1  = scan[best_len-1];
+    register Byte scan_end   = scan[best_len];
+#endif
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    /* Do not waste too much time if we already have a good match: */
+    if (s->prev_length >= s->good_match) {
+        chain_length >>= 2;
+    }
+    /* Do not look for matches beyond the end of the input. This is necessary
+     * to make deflate deterministic.
+     */
+    if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    do {
+        Assert(cur_match < s->strstart, "no future");
+        match = s->window + cur_match;
+
+        /* Skip to next match if the match length cannot increase
+         * or if the match length is less than 2.  Note that the checks below
+         * for insufficient lookahead only occur occasionally for performance
+         * reasons.  Therefore uninitialized memory will be accessed, and
+         * conditional jumps will be made that depend on those values.
+         * However the length of the match is limited to the lookahead, so
+         * the output of deflate is not affected by the uninitialized values.
+         */
+#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
+        /* This code assumes sizeof(unsigned short) == 2. Do not use
+         * UNALIGNED_OK if your compiler uses a different size.
+         */
+        if (*(ushf*)(match+best_len-1) != scan_end ||
+            *(ushf*)match != scan_start) continue;
+
+        /* It is not necessary to compare scan[2] and match[2] since they are
+         * always equal when the other bytes match, given that the hash keys
+         * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
+         * strstart+3, +5, ... up to strstart+257. We check for insufficient
+         * lookahead only every 4th comparison; the 128th check will be made
+         * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
+         * necessary to put more guard bytes at the end of the window, or
+         * to check more often for insufficient lookahead.
+         */
+        Assert(scan[2] == match[2], "scan[2]?");
+        scan++, match++;
+        do {
+        } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 scan < strend);
+        /* The funny "do {}" generates better code on most compilers */
+
+        /* Here, scan <= window+strstart+257 */
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+        if (*scan == *match) scan++;
+
+        len = (MAX_MATCH - 1) - (int)(strend-scan);
+        scan = strend - (MAX_MATCH-1);
+
+#else /* UNALIGNED_OK */
+
+        if (match[best_len]   != scan_end  ||
+            match[best_len-1] != scan_end1 ||
+            *match            != *scan     ||
+            *++match          != scan[1])      continue;
+
+        /* The check at best_len-1 can be removed because it will be made
+         * again later. (This heuristic is not always a win.)
+         * It is not necessary to compare scan[2] and match[2] since they
+         * are always equal when the other bytes match, given that
+         * the hash keys are equal and that HASH_BITS >= 8.
+         */
+        scan += 2, match++;
+        Assert(*scan == *match, "match[2]?");
+
+        /* We check for insufficient lookahead only every 8th comparison;
+         * the 256th check will be made at strstart+258.
+         */
+        do {
+        } while (*++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 scan < strend);
+
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+        len = MAX_MATCH - (int)(strend - scan);
+        scan = strend - MAX_MATCH;
+
+#endif /* UNALIGNED_OK */
+
+        if (len > best_len) {
+            s->match_start = cur_match;
+            best_len = len;
+            if (len >= nice_match) break;
+#ifdef UNALIGNED_OK
+            scan_end = *(ushf*)(scan+best_len-1);
+#else
+            scan_end1  = scan[best_len-1];
+            scan_end   = scan[best_len];
+#endif
+        }
+    } while ((cur_match = prev[cur_match & wmask]) > limit
+             && --chain_length != 0);
+
+    if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+    return s->lookahead;
+}
+#endif /* ASMV */
+
+#else /* FASTEST */
+
+/* ---------------------------------------------------------------------------
+ * Optimized version for FASTEST only
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                       /* matched string */
+    register int len;                           /* length of current match */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    Assert(cur_match < s->strstart, "no future");
+
+    match = s->window + cur_match;
+
+    /* Return failure if the match length is less than 2:
+     */
+    if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
+
+    /* The check at best_len-1 can be removed because it will be made
+     * again later. (This heuristic is not always a win.)
+     * It is not necessary to compare scan[2] and match[2] since they
+     * are always equal when the other bytes match, given that
+     * the hash keys are equal and that HASH_BITS >= 8.
+     */
+    scan += 2, match += 2;
+    Assert(*scan == *match, "match[2]?");
+
+    /* We check for insufficient lookahead only every 8th comparison;
+     * the 256th check will be made at strstart+258.
+     */
+    do {
+    } while (*++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             scan < strend);
+
+    Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+    len = MAX_MATCH - (int)(strend - scan);
+
+    if (len < MIN_MATCH) return MIN_MATCH - 1;
+
+    s->match_start = cur_match;
+    return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
+}
+
+#endif /* FASTEST */
+
+#ifdef ZLIB_DEBUG
+
+#define EQUAL 0
+/* result of memcmp for equal strings */
+
+/* ===========================================================================
+ * Check that the match at match_start is indeed a match.
+ */
+local void check_match(s, start, match, length)
+    deflate_state *s;
+    IPos start, match;
+    int length;
+{
+    /* check that the match is indeed a match */
+    if (zmemcmp(s->window + match,
+                s->window + start, length) != EQUAL) {
+        fprintf(stderr, " start %u, match %u, length %d\n",
+                start, match, length);
+        do {
+            fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
+        } while (--length != 0);
+        z_error("invalid match");
+    }
+    if (z_verbose > 1) {
+        fprintf(stderr,"\\[%d,%d]", start-match, length);
+        do { putc(s->window[start++], stderr); } while (--length != 0);
+    }
+}
+#else
+#  define check_match(s, start, match, length)
+#endif /* ZLIB_DEBUG */
+
+/* ===========================================================================
+ * Fill the window when the lookahead becomes insufficient.
+ * Updates strstart and lookahead.
+ *
+ * IN assertion: lookahead < MIN_LOOKAHEAD
+ * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
+ *    At least one byte has been read, or avail_in == 0; reads are
+ *    performed for at least two bytes (required for the zip translate_eol
+ *    option -- not supported here).
+ */
+local void fill_window(s)
+    deflate_state *s;
+{
+    unsigned n;
+    unsigned more;    /* Amount of free space at the end of the window. */
+    uInt wsize = s->w_size;
+
+    Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
+
+    do {
+        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
+
+        /* Deal with !@#$% 64K limit: */
+        if (sizeof(int) <= 2) {
+            if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
+                more = wsize;
+
+            } else if (more == (unsigned)(-1)) {
+                /* Very unlikely, but possible on 16 bit machine if
+                 * strstart == 0 && lookahead == 1 (input done a byte at time)
+                 */
+                more--;
+            }
+        }
+
+        /* If the window is almost full and there is insufficient lookahead,
+         * move the upper half to the lower one to make room in the upper half.
+         */
+        if (s->strstart >= wsize+MAX_DIST(s)) {
+
+            zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
+            s->match_start -= wsize;
+            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
+            s->block_start -= (long) wsize;
+            slide_hash(s);
+            more += wsize;
+        }
+        if (s->strm->avail_in == 0) break;
+
+        /* If there was no sliding:
+         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
+         *    more == window_size - lookahead - strstart
+         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
+         * => more >= window_size - 2*WSIZE + 2
+         * In the BIG_MEM or MMAP case (not yet supported),
+         *   window_size == input_size + MIN_LOOKAHEAD  &&
+         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
+         * Otherwise, window_size == 2*WSIZE so more >= 2.
+         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
+         */
+        Assert(more >= 2, "more < 2");
+
+        n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
+        s->lookahead += n;
+
+        /* Initialize the hash value now that we have some input: */
+        if (s->lookahead + s->insert >= MIN_MATCH) {
+            uInt str = s->strstart - s->insert;
+            s->ins_h = s->window[str];
+            UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
+#if MIN_MATCH != 3
+            Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+            while (s->insert) {
+                UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
+#ifndef FASTEST
+                s->prev[str & s->w_mask] = s->head[s->ins_h];
+#endif
+                s->head[s->ins_h] = (Pos)str;
+                str++;
+                s->insert--;
+                if (s->lookahead + s->insert < MIN_MATCH)
+                    break;
+            }
+        }
+        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
+         * but this is not important since only literal bytes will be emitted.
+         */
+
+    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
+
+    /* If the WIN_INIT bytes after the end of the current data have never been
+     * written, then zero those bytes in order to avoid memory check reports of
+     * the use of uninitialized (or uninitialised as Julian writes) bytes by
+     * the longest match routines.  Update the high water mark for the next
+     * time through here.  WIN_INIT is set to MAX_MATCH since the longest match
+     * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
+     */
+    if (s->high_water < s->window_size) {
+        ulg curr = s->strstart + (ulg)(s->lookahead);
+        ulg init;
+
+        if (s->high_water < curr) {
+            /* Previous high water mark below current data -- zero WIN_INIT
+             * bytes or up to end of window, whichever is less.
+             */
+            init = s->window_size - curr;
+            if (init > WIN_INIT)
+                init = WIN_INIT;
+            zmemzero(s->window + curr, (unsigned)init);
+            s->high_water = curr + init;
+        }
+        else if (s->high_water < (ulg)curr + WIN_INIT) {
+            /* High water mark at or above current data, but below current data
+             * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
+             * to end of window, whichever is less.
+             */
+            init = (ulg)curr + WIN_INIT - s->high_water;
+            if (init > s->window_size - s->high_water)
+                init = s->window_size - s->high_water;
+            zmemzero(s->window + s->high_water, (unsigned)init);
+            s->high_water += init;
+        }
+    }
+
+    Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
+           "not enough room for search");
+}
+
+/* ===========================================================================
+ * Flush the current block, with given end-of-file flag.
+ * IN assertion: strstart is set to the end of the current match.
+ */
+#define FLUSH_BLOCK_ONLY(s, last) { \
+   _tr_flush_block(s, (s->block_start >= 0L ? \
+                   (charf *)&s->window[(unsigned)s->block_start] : \
+                   (charf *)Z_NULL), \
+                (ulg)((long)s->strstart - s->block_start), \
+                (last)); \
+   s->block_start = s->strstart; \
+   flush_pending(s->strm); \
+   Tracev((stderr,"[FLUSH]")); \
+}
+
+/* Same but force premature exit if necessary. */
+#define FLUSH_BLOCK(s, last) { \
+   FLUSH_BLOCK_ONLY(s, last); \
+   if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
+}
+
+/* Maximum stored block length in deflate format (not including header). */
+#define MAX_STORED 65535
+
+/* Minimum of a and b. */
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+
+/* ===========================================================================
+ * Copy without compression as much as possible from the input stream, return
+ * the current block state.
+ *
+ * In case deflateParams() is used to later switch to a non-zero compression
+ * level, s->matches (otherwise unused when storing) keeps track of the number
+ * of hash table slides to perform. If s->matches is 1, then one hash table
+ * slide will be done when switching. If s->matches is 2, the maximum value
+ * allowed here, then the hash table will be cleared, since two or more slides
+ * is the same as a clear.
+ *
+ * deflate_stored() is written to minimize the number of times an input byte is
+ * copied. It is most efficient with large input and output buffers, which
+ * maximizes the opportunites to have a single copy from next_in to next_out.
+ */
+local block_state deflate_stored(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    /* Smallest worthy block size when not flushing or finishing. By default
+     * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
+     * large input and output buffers, the stored block size will be larger.
+     */
+    unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
+
+    /* Copy as many min_block or larger stored blocks directly to next_out as
+     * possible. If flushing, copy the remaining available input to next_out as
+     * stored blocks, if there is enough space.
+     */
+    unsigned len, left, have, last = 0;
+    unsigned used = s->strm->avail_in;
+    do {
+        /* Set len to the maximum size block that we can copy directly with the
+         * available input data and output space. Set left to how much of that
+         * would be copied from what's left in the window.
+         */
+        len = MAX_STORED;       /* maximum deflate stored block length */
+        have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        if (s->strm->avail_out < have)          /* need room for header */
+            break;
+            /* maximum stored block length that will fit in avail_out: */
+        have = s->strm->avail_out - have;
+        left = s->strstart - s->block_start;    /* bytes left in window */
+        if (len > (ulg)left + s->strm->avail_in)
+            len = left + s->strm->avail_in;     /* limit len to the input */
+        if (len > have)
+            len = have;                         /* limit len to the output */
+
+        /* If the stored block would be less than min_block in length, or if
+         * unable to copy all of the available input when flushing, then try
+         * copying to the window and the pending buffer instead. Also don't
+         * write an empty block when flushing -- deflate() does that.
+         */
+        if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
+                                flush == Z_NO_FLUSH ||
+                                len != left + s->strm->avail_in))
+            break;
+
+        /* Make a dummy stored block in pending to get the header bytes,
+         * including any pending bits. This also updates the debugging counts.
+         */
+        last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
+        _tr_stored_block(s, (char *)0, 0L, last);
+
+        /* Replace the lengths in the dummy stored block with len. */
+        s->pending_buf[s->pending - 4] = len;
+        s->pending_buf[s->pending - 3] = len >> 8;
+        s->pending_buf[s->pending - 2] = ~len;
+        s->pending_buf[s->pending - 1] = ~len >> 8;
+
+        /* Write the stored block header bytes. */
+        flush_pending(s->strm);
+
+#ifdef ZLIB_DEBUG
+        /* Update debugging counts for the data about to be copied. */
+        s->compressed_len += len << 3;
+        s->bits_sent += len << 3;
+#endif
+
+        /* Copy uncompressed bytes from the window to next_out. */
+        if (left) {
+            if (left > len)
+                left = len;
+            zmemcpy(s->strm->next_out, s->window + s->block_start, left);
+            s->strm->next_out += left;
+            s->strm->avail_out -= left;
+            s->strm->total_out += left;
+            s->block_start += left;
+            len -= left;
+        }
+
+        /* Copy uncompressed bytes directly from next_in to next_out, updating
+         * the check value.
+         */
+        if (len) {
+            read_buf(s->strm, s->strm->next_out, len);
+            s->strm->next_out += len;
+            s->strm->avail_out -= len;
+            s->strm->total_out += len;
+        }
+    } while (last == 0);
+
+    /* Update the sliding window with the last s->w_size bytes of the copied
+     * data, or append all of the copied data to the existing window if less
+     * than s->w_size bytes were copied. Also update the number of bytes to
+     * insert in the hash tables, in the event that deflateParams() switches to
+     * a non-zero compression level.
+     */
+    used -= s->strm->avail_in;      /* number of input bytes directly copied */
+    if (used) {
+        /* If any input was used, then no unused input remains in the window,
+         * therefore s->block_start == s->strstart.
+         */
+        if (used >= s->w_size) {    /* supplant the previous history */
+            s->matches = 2;         /* clear hash */
+            zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
+            s->strstart = s->w_size;
+        }
+        else {
+            if (s->window_size - s->strstart <= used) {
+                /* Slide the window down. */
+                s->strstart -= s->w_size;
+                zmemcpy(s->window, s->window + s->w_size, s->strstart);
+                if (s->matches < 2)
+                    s->matches++;   /* add a pending slide_hash() */
+            }
+            zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
+            s->strstart += used;
+        }
+        s->block_start = s->strstart;
+        s->insert += MIN(used, s->w_size - s->insert);
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* If the last block was written to next_out, then done. */
+    if (last)
+        return finish_done;
+
+    /* If flushing and all input has been consumed, then done. */
+    if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
+        s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
+        return block_done;
+
+    /* Fill the window with any remaining input. */
+    have = s->window_size - s->strstart - 1;
+    if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
+        /* Slide the window down. */
+        s->block_start -= s->w_size;
+        s->strstart -= s->w_size;
+        zmemcpy(s->window, s->window + s->w_size, s->strstart);
+        if (s->matches < 2)
+            s->matches++;           /* add a pending slide_hash() */
+        have += s->w_size;          /* more space now */
+    }
+    if (have > s->strm->avail_in)
+        have = s->strm->avail_in;
+    if (have) {
+        read_buf(s->strm, s->window + s->strstart, have);
+        s->strstart += have;
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* There was not enough avail_out to write a complete worthy or flushed
+     * stored block to next_out. Write a stored block to pending instead, if we
+     * have enough input for a worthy block, or if flushing and there is enough
+     * room for the remaining input as a stored block in the pending buffer.
+     */
+    have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        /* maximum stored block length that will fit in pending: */
+    have = MIN(s->pending_buf_size - have, MAX_STORED);
+    min_block = MIN(have, s->w_size);
+    left = s->strstart - s->block_start;
+    if (left >= min_block ||
+        ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
+         s->strm->avail_in == 0 && left <= have)) {
+        len = MIN(left, have);
+        last = flush == Z_FINISH && s->strm->avail_in == 0 &&
+               len == left ? 1 : 0;
+        _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
+        s->block_start += len;
+        flush_pending(s->strm);
+    }
+
+    /* We've done all we can with the available input and output. */
+    return last ? finish_started : need_more;
+}
+
+/* ===========================================================================
+ * Compress as much as possible from the input stream, return the current
+ * block state.
+ * This function does not perform lazy evaluation of matches and inserts
+ * new strings in the dictionary only for unmatched strings or for short
+ * matches. It is used only for the fast compression options.
+ */
+local block_state deflate_fast(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head;       /* head of the hash chain */
+    int bflush;           /* set if current block must be flushed */
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        hash_head = NIL;
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         * At this point we have always match_length < MIN_MATCH
+         */
+        if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            s->match_length = longest_match (s, hash_head);
+            /* longest_match() sets match_start */
+        }
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->match_start, s->match_length);
+
+            _tr_tally_dist(s, s->strstart - s->match_start,
+                           s->match_length - MIN_MATCH, bflush);
+
+            s->lookahead -= s->match_length;
+
+            /* Insert new strings in the hash table only if the match length
+             * is not too large. This saves time but degrades compression.
+             */
+#ifndef FASTEST
+            if (s->match_length <= s->max_insert_length &&
+                s->lookahead >= MIN_MATCH) {
+                s->match_length--; /* string at strstart already in table */
+                do {
+                    s->strstart++;
+                    INSERT_STRING(s, s->strstart, hash_head);
+                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
+                     * always MIN_MATCH bytes ahead.
+                     */
+                } while (--s->match_length != 0);
+                s->strstart++;
+            } else
+#endif
+            {
+                s->strstart += s->match_length;
+                s->match_length = 0;
+                s->ins_h = s->window[s->strstart];
+                UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
+#if MIN_MATCH != 3
+                Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+                /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
+                 * matter since it will be recomputed at next deflate call.
+                 */
+            }
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
+            s->lookahead--;
+            s->strstart++;
+        }
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+
+#ifndef FASTEST
+/* ===========================================================================
+ * Same as above, but achieves better compression. We use a lazy
+ * evaluation for matches: a match is finally adopted only if there is
+ * no better match at the next window position.
+ */
+local block_state deflate_slow(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head;          /* head of hash chain */
+    int bflush;              /* set if current block must be flushed */
+
+    /* Process the input block. */
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        hash_head = NIL;
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         */
+        s->prev_length = s->match_length, s->prev_match = s->match_start;
+        s->match_length = MIN_MATCH-1;
+
+        if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
+            s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            s->match_length = longest_match (s, hash_head);
+            /* longest_match() sets match_start */
+
+            if (s->match_length <= 5 && (s->strategy == Z_FILTERED
+#if TOO_FAR <= 32767
+                || (s->match_length == MIN_MATCH &&
+                    s->strstart - s->match_start > TOO_FAR)
+#endif
+                )) {
+
+                /* If prev_match is also MIN_MATCH, match_start is garbage
+                 * but we will ignore the current match anyway.
+                 */
+                s->match_length = MIN_MATCH-1;
+            }
+        }
+        /* If there was a match at the previous step and the current
+         * match is not better, output the previous match:
+         */
+        if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
+            uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
+            /* Do not insert strings in hash table beyond this. */
+
+            check_match(s, s->strstart-1, s->prev_match, s->prev_length);
+
+            _tr_tally_dist(s, s->strstart -1 - s->prev_match,
+                           s->prev_length - MIN_MATCH, bflush);
+
+            /* Insert in hash table all strings up to the end of the match.
+             * strstart-1 and strstart are already inserted. If there is not
+             * enough lookahead, the last two strings are not inserted in
+             * the hash table.
+             */
+            s->lookahead -= s->prev_length-1;
+            s->prev_length -= 2;
+            do {
+                if (++s->strstart <= max_insert) {
+                    INSERT_STRING(s, s->strstart, hash_head);
+                }
+            } while (--s->prev_length != 0);
+            s->match_available = 0;
+            s->match_length = MIN_MATCH-1;
+            s->strstart++;
+
+            if (bflush) FLUSH_BLOCK(s, 0);
+
+        } else if (s->match_available) {
+            /* If there was no match at the previous position, output a
+             * single literal. If there was a match but the current match
+             * is longer, truncate the previous match to a single literal.
+             */
+            Tracevv((stderr,"%c", s->window[s->strstart-1]));
+            _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+            if (bflush) {
+                FLUSH_BLOCK_ONLY(s, 0);
+            }
+            s->strstart++;
+            s->lookahead--;
+            if (s->strm->avail_out == 0) return need_more;
+        } else {
+            /* There is no previous match to compare with, wait for
+             * the next step to decide.
+             */
+            s->match_available = 1;
+            s->strstart++;
+            s->lookahead--;
+        }
+    }
+    Assert (flush != Z_NO_FLUSH, "no flush?");
+    if (s->match_available) {
+        Tracevv((stderr,"%c", s->window[s->strstart-1]));
+        _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+        s->match_available = 0;
+    }
+    s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+#endif /* FASTEST */
+
+/* ===========================================================================
+ * For Z_RLE, simply look for runs of bytes, generate matches only of distance
+ * one.  Do not maintain a hash table.  (It will be regenerated if this run of
+ * deflate switches away from Z_RLE.)
+ */
+local block_state deflate_rle(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    int bflush;             /* set if current block must be flushed */
+    uInt prev;              /* byte at distance one to match */
+    Bytef *scan, *strend;   /* scan goes up to strend for length of run */
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the longest run, plus one for the unrolled loop.
+         */
+        if (s->lookahead <= MAX_MATCH) {
+            fill_window(s);
+            if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* See how many times the previous byte repeats */
+        s->match_length = 0;
+        if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
+            scan = s->window + s->strstart - 1;
+            prev = *scan;
+            if (prev == *++scan && prev == *++scan && prev == *++scan) {
+                strend = s->window + s->strstart + MAX_MATCH;
+                do {
+                } while (prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         scan < strend);
+                s->match_length = MAX_MATCH - (uInt)(strend - scan);
+                if (s->match_length > s->lookahead)
+                    s->match_length = s->lookahead;
+            }
+            Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
+        }
+
+        /* Emit match if have run of MIN_MATCH or longer, else emit literal */
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->strstart - 1, s->match_length);
+
+            _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
+
+            s->lookahead -= s->match_length;
+            s->strstart += s->match_length;
+            s->match_length = 0;
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
+            s->lookahead--;
+            s->strstart++;
+        }
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = 0;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+
+/* ===========================================================================
+ * For Z_HUFFMAN_ONLY, do not look for matches.  Do not maintain a hash table.
+ * (It will be regenerated if this run of deflate switches away from Huffman.)
+ */
+local block_state deflate_huff(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    int bflush;             /* set if current block must be flushed */
+
+    for (;;) {
+        /* Make sure that we have a literal to write. */
+        if (s->lookahead == 0) {
+            fill_window(s);
+            if (s->lookahead == 0) {
+                if (flush == Z_NO_FLUSH)
+                    return need_more;
+                break;      /* flush the current block */
+            }
+        }
+
+        /* Output a literal byte */
+        s->match_length = 0;
+        Tracevv((stderr,"%c", s->window[s->strstart]));
+        _tr_tally_lit (s, s->window[s->strstart], bflush);
+        s->lookahead--;
+        s->strstart++;
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = 0;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
diff --git a/xs/src/png/zlib/deflate.h b/xs/src/png/zlib/deflate.h
new file mode 100644
index 000000000..23ecdd312
--- /dev/null
+++ b/xs/src/png/zlib/deflate.h
@@ -0,0 +1,349 @@
+/* deflate.h -- internal compression state
+ * Copyright (C) 1995-2016 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id$ */
+
+#ifndef DEFLATE_H
+#define DEFLATE_H
+
+#include "zutil.h"
+
+/* define NO_GZIP when compiling if you want to disable gzip header and
+   trailer creation by deflate().  NO_GZIP would be used to avoid linking in
+   the crc code when it is not needed.  For shared libraries, gzip encoding
+   should be left enabled. */
+#ifndef NO_GZIP
+#  define GZIP
+#endif
+
+/* ===========================================================================
+ * Internal compression state.
+ */
+
+#define LENGTH_CODES 29
+/* number of length codes, not counting the special END_BLOCK code */
+
+#define LITERALS  256
+/* number of literal bytes 0..255 */
+
+#define L_CODES (LITERALS+1+LENGTH_CODES)
+/* number of Literal or Length codes, including the END_BLOCK code */
+
+#define D_CODES   30
+/* number of distance codes */
+
+#define BL_CODES  19
+/* number of codes used to transfer the bit lengths */
+
+#define HEAP_SIZE (2*L_CODES+1)
+/* maximum heap size */
+
+#define MAX_BITS 15
+/* All codes must not exceed MAX_BITS bits */
+
+#define Buf_size 16
+/* size of bit buffer in bi_buf */
+
+#define INIT_STATE    42    /* zlib header -> BUSY_STATE */
+#ifdef GZIP
+#  define GZIP_STATE  57    /* gzip header -> BUSY_STATE | EXTRA_STATE */
+#endif
+#define EXTRA_STATE   69    /* gzip extra block -> NAME_STATE */
+#define NAME_STATE    73    /* gzip file name -> COMMENT_STATE */
+#define COMMENT_STATE 91    /* gzip comment -> HCRC_STATE */
+#define HCRC_STATE   103    /* gzip header CRC -> BUSY_STATE */
+#define BUSY_STATE   113    /* deflate -> FINISH_STATE */
+#define FINISH_STATE 666    /* stream complete */
+/* Stream status */
+
+
+/* Data structure describing a single value and its code string. */
+typedef struct ct_data_s {
+    union {
+        ush  freq;       /* frequency count */
+        ush  code;       /* bit string */
+    } fc;
+    union {
+        ush  dad;        /* father node in Huffman tree */
+        ush  len;        /* length of bit string */
+    } dl;
+} FAR ct_data;
+
+#define Freq fc.freq
+#define Code fc.code
+#define Dad  dl.dad
+#define Len  dl.len
+
+typedef struct static_tree_desc_s  static_tree_desc;
+
+typedef struct tree_desc_s {
+    ct_data *dyn_tree;           /* the dynamic tree */
+    int     max_code;            /* largest code with non zero frequency */
+    const static_tree_desc *stat_desc;  /* the corresponding static tree */
+} FAR tree_desc;
+
+typedef ush Pos;
+typedef Pos FAR Posf;
+typedef unsigned IPos;
+
+/* A Pos is an index in the character window. We use short instead of int to
+ * save space in the various tables. IPos is used only for parameter passing.
+ */
+
+typedef struct internal_state {
+    z_streamp strm;      /* pointer back to this zlib stream */
+    int   status;        /* as the name implies */
+    Bytef *pending_buf;  /* output still pending */
+    ulg   pending_buf_size; /* size of pending_buf */
+    Bytef *pending_out;  /* next pending byte to output to the stream */
+    ulg   pending;       /* nb of bytes in the pending buffer */
+    int   wrap;          /* bit 0 true for zlib, bit 1 true for gzip */
+    gz_headerp  gzhead;  /* gzip header information to write */
+    ulg   gzindex;       /* where in extra, name, or comment */
+    Byte  method;        /* can only be DEFLATED */
+    int   last_flush;    /* value of flush param for previous deflate call */
+
+                /* used by deflate.c: */
+
+    uInt  w_size;        /* LZ77 window size (32K by default) */
+    uInt  w_bits;        /* log2(w_size)  (8..16) */
+    uInt  w_mask;        /* w_size - 1 */
+
+    Bytef *window;
+    /* Sliding window. Input bytes are read into the second half of the window,
+     * and move to the first half later to keep a dictionary of at least wSize
+     * bytes. With this organization, matches are limited to a distance of
+     * wSize-MAX_MATCH bytes, but this ensures that IO is always
+     * performed with a length multiple of the block size. Also, it limits
+     * the window size to 64K, which is quite useful on MSDOS.
+     * To do: use the user input buffer as sliding window.
+     */
+
+    ulg window_size;
+    /* Actual size of window: 2*wSize, except when the user input buffer
+     * is directly used as sliding window.
+     */
+
+    Posf *prev;
+    /* Link to older string with same hash index. To limit the size of this
+     * array to 64K, this link is maintained only for the last 32K strings.
+     * An index in this array is thus a window index modulo 32K.
+     */
+
+    Posf *head; /* Heads of the hash chains or NIL. */
+
+    uInt  ins_h;          /* hash index of string to be inserted */
+    uInt  hash_size;      /* number of elements in hash table */
+    uInt  hash_bits;      /* log2(hash_size) */
+    uInt  hash_mask;      /* hash_size-1 */
+
+    uInt  hash_shift;
+    /* Number of bits by which ins_h must be shifted at each input
+     * step. It must be such that after MIN_MATCH steps, the oldest
+     * byte no longer takes part in the hash key, that is:
+     *   hash_shift * MIN_MATCH >= hash_bits
+     */
+
+    long block_start;
+    /* Window position at the beginning of the current output block. Gets
+     * negative when the window is moved backwards.
+     */
+
+    uInt match_length;           /* length of best match */
+    IPos prev_match;             /* previous match */
+    int match_available;         /* set if previous match exists */
+    uInt strstart;               /* start of string to insert */
+    uInt match_start;            /* start of matching string */
+    uInt lookahead;              /* number of valid bytes ahead in window */
+
+    uInt prev_length;
+    /* Length of the best match at previous step. Matches not greater than this
+     * are discarded. This is used in the lazy match evaluation.
+     */
+
+    uInt max_chain_length;
+    /* To speed up deflation, hash chains are never searched beyond this
+     * length.  A higher limit improves compression ratio but degrades the
+     * speed.
+     */
+
+    uInt max_lazy_match;
+    /* Attempt to find a better match only when the current match is strictly
+     * smaller than this value. This mechanism is used only for compression
+     * levels >= 4.
+     */
+#   define max_insert_length  max_lazy_match
+    /* Insert new strings in the hash table only if the match length is not
+     * greater than this length. This saves time but degrades compression.
+     * max_insert_length is used only for compression levels <= 3.
+     */
+
+    int level;    /* compression level (1..9) */
+    int strategy; /* favor or force Huffman coding*/
+
+    uInt good_match;
+    /* Use a faster search when the previous match is longer than this */
+
+    int nice_match; /* Stop searching when current match exceeds this */
+
+                /* used by trees.c: */
+    /* Didn't use ct_data typedef below to suppress compiler warning */
+    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
+    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
+    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
+
+    struct tree_desc_s l_desc;               /* desc. for literal tree */
+    struct tree_desc_s d_desc;               /* desc. for distance tree */
+    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
+
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
+    int heap_len;               /* number of elements in the heap */
+    int heap_max;               /* element of largest frequency */
+    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
+     * The same heap array is used to build all trees.
+     */
+
+    uch depth[2*L_CODES+1];
+    /* Depth of each subtree used as tie breaker for trees of equal frequency
+     */
+
+    uchf *l_buf;          /* buffer for literals or lengths */
+
+    uInt  lit_bufsize;
+    /* Size of match buffer for literals/lengths.  There are 4 reasons for
+     * limiting lit_bufsize to 64K:
+     *   - frequencies can be kept in 16 bit counters
+     *   - if compression is not successful for the first block, all input
+     *     data is still in the window so we can still emit a stored block even
+     *     when input comes from standard input.  (This can also be done for
+     *     all blocks if lit_bufsize is not greater than 32K.)
+     *   - if compression is not successful for a file smaller than 64K, we can
+     *     even emit a stored file instead of a stored block (saving 5 bytes).
+     *     This is applicable only for zip (not gzip or zlib).
+     *   - creating new Huffman trees less frequently may not provide fast
+     *     adaptation to changes in the input data statistics. (Take for
+     *     example a binary file with poorly compressible code followed by
+     *     a highly compressible string table.) Smaller buffer sizes give
+     *     fast adaptation but have of course the overhead of transmitting
+     *     trees more frequently.
+     *   - I can't count above 4
+     */
+
+    uInt last_lit;      /* running index in l_buf */
+
+    ushf *d_buf;
+    /* Buffer for distances. To simplify the code, d_buf and l_buf have
+     * the same number of elements. To use different lengths, an extra flag
+     * array would be necessary.
+     */
+
+    ulg opt_len;        /* bit length of current block with optimal trees */
+    ulg static_len;     /* bit length of current block with static trees */
+    uInt matches;       /* number of string matches in current block */
+    uInt insert;        /* bytes at end of window left to insert */
+
+#ifdef ZLIB_DEBUG
+    ulg compressed_len; /* total bit length of compressed file mod 2^32 */
+    ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
+#endif
+
+    ush bi_buf;
+    /* Output buffer. bits are inserted starting at the bottom (least
+     * significant bits).
+     */
+    int bi_valid;
+    /* Number of valid bits in bi_buf.  All bits above the last valid bit
+     * are always zero.
+     */
+
+    ulg high_water;
+    /* High water mark offset in window for initialized bytes -- bytes above
+     * this are set to zero in order to avoid memory check warnings when
+     * longest match routines access bytes past the input.  This is then
+     * updated to the new high water mark.
+     */
+
+} FAR deflate_state;
+
+/* Output a byte on the stream.
+ * IN assertion: there is enough room in pending_buf.
+ */
+#define put_byte(s, c) {s->pending_buf[s->pending++] = (Bytef)(c);}
+
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
+/* In order to simplify the code, particularly on 16 bit machines, match
+ * distances are limited to MAX_DIST instead of WSIZE.
+ */
+
+#define WIN_INIT MAX_MATCH
+/* Number of bytes after end of data in window to initialize in order to avoid
+   memory checker errors from longest match routines */
+
+        /* in trees.c */
+void ZLIB_INTERNAL _tr_init OF((deflate_state *s));
+int ZLIB_INTERNAL _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
+void ZLIB_INTERNAL _tr_flush_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+void ZLIB_INTERNAL _tr_flush_bits OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_align OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+
+#define d_code(dist) \
+   ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. _dist_code[256] and _dist_code[257] are never
+ * used.
+ */
+
+#ifndef ZLIB_DEBUG
+/* Inline versions of _tr_tally for speed: */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+  extern uch ZLIB_INTERNAL _length_code[];
+  extern uch ZLIB_INTERNAL _dist_code[];
+#else
+  extern const uch ZLIB_INTERNAL _length_code[];
+  extern const uch ZLIB_INTERNAL _dist_code[];
+#endif
+
+# define _tr_tally_lit(s, c, flush) \
+  { uch cc = (c); \
+    s->d_buf[s->last_lit] = 0; \
+    s->l_buf[s->last_lit++] = cc; \
+    s->dyn_ltree[cc].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+   }
+# define _tr_tally_dist(s, distance, length, flush) \
+  { uch len = (uch)(length); \
+    ush dist = (ush)(distance); \
+    s->d_buf[s->last_lit] = dist; \
+    s->l_buf[s->last_lit++] = len; \
+    dist--; \
+    s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
+    s->dyn_dtree[d_code(dist)].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+  }
+#else
+# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
+# define _tr_tally_dist(s, distance, length, flush) \
+              flush = _tr_tally(s, distance, length)
+#endif
+
+#endif /* DEFLATE_H */
diff --git a/xs/src/png/zlib/gzclose.c b/xs/src/png/zlib/gzclose.c
new file mode 100644
index 000000000..caeb99a31
--- /dev/null
+++ b/xs/src/png/zlib/gzclose.c
@@ -0,0 +1,25 @@
+/* gzclose.c -- zlib gzclose() function
+ * Copyright (C) 2004, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* gzclose() is in a separate file so that it is linked in only if it is used.
+   That way the other gzclose functions can be used instead to avoid linking in
+   unneeded compression or decompression routines. */
+int ZEXPORT gzclose(file)
+    gzFile file;
+{
+#ifndef NO_GZCOMPRESS
+    gz_statep state;
+
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    return state->mode == GZ_READ ? gzclose_r(file) : gzclose_w(file);
+#else
+    return gzclose_r(file);
+#endif
+}
diff --git a/xs/src/png/zlib/gzguts.h b/xs/src/png/zlib/gzguts.h
new file mode 100644
index 000000000..990a4d251
--- /dev/null
+++ b/xs/src/png/zlib/gzguts.h
@@ -0,0 +1,218 @@
+/* gzguts.h -- zlib internal header definitions for gz* operations
+ * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#ifdef _LARGEFILE64_SOURCE
+#  ifndef _LARGEFILE_SOURCE
+#    define _LARGEFILE_SOURCE 1
+#  endif
+#  ifdef _FILE_OFFSET_BITS
+#    undef _FILE_OFFSET_BITS
+#  endif
+#endif
+
+#ifdef HAVE_HIDDEN
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
+#include <stdio.h>
+#include "zlib.h"
+#ifdef STDC
+#  include <string.h>
+#  include <stdlib.h>
+#  include <limits.h>
+#endif
+
+#ifndef _POSIX_SOURCE
+#  define _POSIX_SOURCE
+#endif
+#include <fcntl.h>
+
+#ifdef _WIN32
+#  include <stddef.h>
+#endif
+
+#if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
+#  include <io.h>
+#endif
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+#  define WIDECHAR
+#endif
+
+#ifdef WINAPI_FAMILY
+#  define open _open
+#  define read _read
+#  define write _write
+#  define close _close
+#endif
+
+#ifdef NO_DEFLATE       /* for compatibility with old definition */
+#  define NO_GZCOMPRESS
+#endif
+
+#if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#if defined(__CYGWIN__)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#ifndef HAVE_VSNPRINTF
+#  ifdef MSDOS
+/* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
+   but for now we just assume it doesn't. */
+#    define NO_vsnprintf
+#  endif
+#  ifdef __TURBOC__
+#    define NO_vsnprintf
+#  endif
+#  ifdef WIN32
+/* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
+#    if !defined(vsnprintf) && !defined(NO_vsnprintf)
+#      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
+#         define vsnprintf _vsnprintf
+#      endif
+#    endif
+#  endif
+#  ifdef __SASC
+#    define NO_vsnprintf
+#  endif
+#  ifdef VMS
+#    define NO_vsnprintf
+#  endif
+#  ifdef __OS400__
+#    define NO_vsnprintf
+#  endif
+#  ifdef __MVS__
+#    define NO_vsnprintf
+#  endif
+#endif
+
+/* unlike snprintf (which is required in C99), _snprintf does not guarantee
+   null termination of the result -- however this is only used in gzlib.c where
+   the result is assured to fit in the space provided */
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#  define snprintf _snprintf
+#endif
+
+#ifndef local
+#  define local static
+#endif
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
+
+/* gz* functions always use library allocation functions */
+#ifndef STDC
+  extern voidp  malloc OF((uInt size));
+  extern void   free   OF((voidpf ptr));
+#endif
+
+/* get errno and strerror definition */
+#if defined UNDER_CE
+#  include <windows.h>
+#  define zstrerror() gz_strwinerror((DWORD)GetLastError())
+#else
+#  ifndef NO_STRERROR
+#    include <errno.h>
+#    define zstrerror() strerror(errno)
+#  else
+#    define zstrerror() "stdio error (consult errno)"
+#  endif
+#endif
+
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
+    ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+    ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+    ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+    ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+#endif
+
+/* default memLevel */
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+
+/* default i/o buffer size -- double this for output when reading (this and
+   twice this must be able to fit in an unsigned type) */
+#define GZBUFSIZE 8192
+
+/* gzip modes, also provide a little integrity check on the passed structure */
+#define GZ_NONE 0
+#define GZ_READ 7247
+#define GZ_WRITE 31153
+#define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
+
+/* values for gz_state how */
+#define LOOK 0      /* look for a gzip header */
+#define COPY 1      /* copy input directly */
+#define GZIP 2      /* decompress a gzip stream */
+
+/* internal gzip file state data structure */
+typedef struct {
+        /* exposed contents for gzgetc() macro */
+    struct gzFile_s x;      /* "x" for exposed */
+                            /* x.have: number of bytes available at x.next */
+                            /* x.next: next output data to deliver or write */
+                            /* x.pos: current position in uncompressed data */
+        /* used for both reading and writing */
+    int mode;               /* see gzip modes above */
+    int fd;                 /* file descriptor */
+    char *path;             /* path or fd for error messages */
+    unsigned size;          /* buffer size, zero if not allocated yet */
+    unsigned want;          /* requested buffer size, default is GZBUFSIZE */
+    unsigned char *in;      /* input buffer (double-sized when writing) */
+    unsigned char *out;     /* output buffer (double-sized when reading) */
+    int direct;             /* 0 if processing gzip, 1 if transparent */
+        /* just for reading */
+    int how;                /* 0: get header, 1: copy, 2: decompress */
+    z_off64_t start;        /* where the gzip data started, for rewinding */
+    int eof;                /* true if end of input file reached */
+    int past;               /* true if read requested past end */
+        /* just for writing */
+    int level;              /* compression level */
+    int strategy;           /* compression strategy */
+        /* seek request */
+    z_off64_t skip;         /* amount to skip (already rewound if backwards) */
+    int seek;               /* true if seek request pending */
+        /* error information */
+    int err;                /* error code */
+    char *msg;              /* error message */
+        /* zlib inflate or deflate stream */
+    z_stream strm;          /* stream structure in-place (not a pointer) */
+} gz_state;
+typedef gz_state FAR *gz_statep;
+
+/* shared functions */
+void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
+#if defined UNDER_CE
+char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
+#endif
+
+/* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
+   value -- needed when comparing unsigned to z_off64_t, which is signed
+   (possible z_off64_t types off_t, off64_t, and long are all signed) */
+#ifdef INT_MAX
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
+#else
+unsigned ZLIB_INTERNAL gz_intmax OF((void));
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
+#endif
diff --git a/xs/src/png/zlib/gzlib.c b/xs/src/png/zlib/gzlib.c
new file mode 100644
index 000000000..4105e6aff
--- /dev/null
+++ b/xs/src/png/zlib/gzlib.c
@@ -0,0 +1,637 @@
+/* gzlib.c -- zlib functions common to reading and writing gzip files
+ * Copyright (C) 2004-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+#if defined(_WIN32) && !defined(__BORLANDC__) && !defined(__MINGW32__)
+#  define LSEEK _lseeki64
+#else
+#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
+#  define LSEEK lseek64
+#else
+#  define LSEEK lseek
+#endif
+#endif
+
+/* Local functions */
+local void gz_reset OF((gz_statep));
+local gzFile gz_open OF((const void *, int, const char *));
+
+#if defined UNDER_CE
+
+/* Map the Windows error number in ERROR to a locale-dependent error message
+   string and return a pointer to it.  Typically, the values for ERROR come
+   from GetLastError.
+
+   The string pointed to shall not be modified by the application, but may be
+   overwritten by a subsequent call to gz_strwinerror
+
+   The gz_strwinerror function does not change the current setting of
+   GetLastError. */
+char ZLIB_INTERNAL *gz_strwinerror (error)
+     DWORD error;
+{
+    static char buf[1024];
+
+    wchar_t *msgbuf;
+    DWORD lasterr = GetLastError();
+    DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
+        | FORMAT_MESSAGE_ALLOCATE_BUFFER,
+        NULL,
+        error,
+        0, /* Default language */
+        (LPVOID)&msgbuf,
+        0,
+        NULL);
+    if (chars != 0) {
+        /* If there is an \r\n appended, zap it.  */
+        if (chars >= 2
+            && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
+            chars -= 2;
+            msgbuf[chars] = 0;
+        }
+
+        if (chars > sizeof (buf) - 1) {
+            chars = sizeof (buf) - 1;
+            msgbuf[chars] = 0;
+        }
+
+        wcstombs(buf, msgbuf, chars + 1);
+        LocalFree(msgbuf);
+    }
+    else {
+        sprintf(buf, "unknown win32 error (%ld)", error);
+    }
+
+    SetLastError(lasterr);
+    return buf;
+}
+
+#endif /* UNDER_CE */
+
+/* Reset gzip file state */
+local void gz_reset(state)
+    gz_statep state;
+{
+    state->x.have = 0;              /* no output data available */
+    if (state->mode == GZ_READ) {   /* for reading ... */
+        state->eof = 0;             /* not at end of file */
+        state->past = 0;            /* have not read past end yet */
+        state->how = LOOK;          /* look for gzip header */
+    }
+    state->seek = 0;                /* no seek request pending */
+    gz_error(state, Z_OK, NULL);    /* clear error */
+    state->x.pos = 0;               /* no uncompressed data yet */
+    state->strm.avail_in = 0;       /* no input data yet */
+}
+
+/* Open a gzip file either by name or file descriptor. */
+local gzFile gz_open(path, fd, mode)
+    const void *path;
+    int fd;
+    const char *mode;
+{
+    gz_statep state;
+    z_size_t len;
+    int oflag;
+#ifdef O_CLOEXEC
+    int cloexec = 0;
+#endif
+#ifdef O_EXCL
+    int exclusive = 0;
+#endif
+
+    /* check input */
+    if (path == NULL)
+        return NULL;
+
+    /* allocate gzFile structure to return */
+    state = (gz_statep)malloc(sizeof(gz_state));
+    if (state == NULL)
+        return NULL;
+    state->size = 0;            /* no buffers allocated yet */
+    state->want = GZBUFSIZE;    /* requested buffer size */
+    state->msg = NULL;          /* no error message yet */
+
+    /* interpret mode */
+    state->mode = GZ_NONE;
+    state->level = Z_DEFAULT_COMPRESSION;
+    state->strategy = Z_DEFAULT_STRATEGY;
+    state->direct = 0;
+    while (*mode) {
+        if (*mode >= '0' && *mode <= '9')
+            state->level = *mode - '0';
+        else
+            switch (*mode) {
+            case 'r':
+                state->mode = GZ_READ;
+                break;
+#ifndef NO_GZCOMPRESS
+            case 'w':
+                state->mode = GZ_WRITE;
+                break;
+            case 'a':
+                state->mode = GZ_APPEND;
+                break;
+#endif
+            case '+':       /* can't read and write at the same time */
+                free(state);
+                return NULL;
+            case 'b':       /* ignore -- will request binary anyway */
+                break;
+#ifdef O_CLOEXEC
+            case 'e':
+                cloexec = 1;
+                break;
+#endif
+#ifdef O_EXCL
+            case 'x':
+                exclusive = 1;
+                break;
+#endif
+            case 'f':
+                state->strategy = Z_FILTERED;
+                break;
+            case 'h':
+                state->strategy = Z_HUFFMAN_ONLY;
+                break;
+            case 'R':
+                state->strategy = Z_RLE;
+                break;
+            case 'F':
+                state->strategy = Z_FIXED;
+                break;
+            case 'T':
+                state->direct = 1;
+                break;
+            default:        /* could consider as an error, but just ignore */
+                ;
+            }
+        mode++;
+    }
+
+    /* must provide an "r", "w", or "a" */
+    if (state->mode == GZ_NONE) {
+        free(state);
+        return NULL;
+    }
+
+    /* can't force transparent read */
+    if (state->mode == GZ_READ) {
+        if (state->direct) {
+            free(state);
+            return NULL;
+        }
+        state->direct = 1;      /* for empty file */
+    }
+
+    /* save the path name for error messages */
+#ifdef WIDECHAR
+    if (fd == -2) {
+        len = wcstombs(NULL, path, 0);
+        if (len == (z_size_t)-1)
+            len = 0;
+    }
+    else
+#endif
+        len = strlen((const char *)path);
+    state->path = (char *)malloc(len + 1);
+    if (state->path == NULL) {
+        free(state);
+        return NULL;
+    }
+#ifdef WIDECHAR
+    if (fd == -2)
+        if (len)
+            wcstombs(state->path, path, len + 1);
+        else
+            *(state->path) = 0;
+    else
+#endif
+#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
+        (void)snprintf(state->path, len + 1, "%s", (const char *)path);
+#else
+        strcpy(state->path, path);
+#endif
+
+    /* compute the flags for open() */
+    oflag =
+#ifdef O_LARGEFILE
+        O_LARGEFILE |
+#endif
+#ifdef O_BINARY
+        O_BINARY |
+#endif
+#ifdef O_CLOEXEC
+        (cloexec ? O_CLOEXEC : 0) |
+#endif
+        (state->mode == GZ_READ ?
+         O_RDONLY :
+         (O_WRONLY | O_CREAT |
+#ifdef O_EXCL
+          (exclusive ? O_EXCL : 0) |
+#endif
+          (state->mode == GZ_WRITE ?
+           O_TRUNC :
+           O_APPEND)));
+
+    /* open the file with the appropriate flags (or just use fd) */
+    state->fd = fd > -1 ? fd : (
+#ifdef WIDECHAR
+        fd == -2 ? _wopen(path, oflag, 0666) :
+#endif
+        open((const char *)path, oflag, 0666));
+    if (state->fd == -1) {
+        free(state->path);
+        free(state);
+        return NULL;
+    }
+    if (state->mode == GZ_APPEND) {
+        LSEEK(state->fd, 0, SEEK_END);  /* so gzoffset() is correct */
+        state->mode = GZ_WRITE;         /* simplify later checks */
+    }
+
+    /* save the current position for rewinding (only if reading) */
+    if (state->mode == GZ_READ) {
+        state->start = LSEEK(state->fd, 0, SEEK_CUR);
+        if (state->start == -1) state->start = 0;
+    }
+
+    /* initialize stream */
+    gz_reset(state);
+
+    /* return stream */
+    return (gzFile)state;
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzopen(path, mode)
+    const char *path;
+    const char *mode;
+{
+    return gz_open(path, -1, mode);
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzopen64(path, mode)
+    const char *path;
+    const char *mode;
+{
+    return gz_open(path, -1, mode);
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzdopen(fd, mode)
+    int fd;
+    const char *mode;
+{
+    char *path;         /* identifier for error messages */
+    gzFile gz;
+
+    if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
+        return NULL;
+#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
+    (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
+#else
+    sprintf(path, "<fd:%d>", fd);   /* for debugging */
+#endif
+    gz = gz_open(path, fd, mode);
+    free(path);
+    return gz;
+}
+
+/* -- see zlib.h -- */
+#ifdef WIDECHAR
+gzFile ZEXPORT gzopen_w(path, mode)
+    const wchar_t *path;
+    const char *mode;
+{
+    return gz_open(path, -2, mode);
+}
+#endif
+
+/* -- see zlib.h -- */
+int ZEXPORT gzbuffer(file, size)
+    gzFile file;
+    unsigned size;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* make sure we haven't already allocated memory */
+    if (state->size != 0)
+        return -1;
+
+    /* check and set requested size */
+    if ((size << 1) < size)
+        return -1;              /* need to be able to double it */
+    if (size < 2)
+        size = 2;               /* need two bytes to check magic header */
+    state->want = size;
+    return 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzrewind(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ ||
+            (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* back up and start over */
+    if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
+        return -1;
+    gz_reset(state);
+    return 0;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gzseek64(file, offset, whence)
+    gzFile file;
+    z_off64_t offset;
+    int whence;
+{
+    unsigned n;
+    z_off64_t ret;
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* check that there's no error */
+    if (state->err != Z_OK && state->err != Z_BUF_ERROR)
+        return -1;
+
+    /* can only seek from start or relative to current position */
+    if (whence != SEEK_SET && whence != SEEK_CUR)
+        return -1;
+
+    /* normalize offset to a SEEK_CUR specification */
+    if (whence == SEEK_SET)
+        offset -= state->x.pos;
+    else if (state->seek)
+        offset += state->skip;
+    state->seek = 0;
+
+    /* if within raw area while reading, just go there */
+    if (state->mode == GZ_READ && state->how == COPY &&
+            state->x.pos + offset >= 0) {
+        ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
+        if (ret == -1)
+            return -1;
+        state->x.have = 0;
+        state->eof = 0;
+        state->past = 0;
+        state->seek = 0;
+        gz_error(state, Z_OK, NULL);
+        state->strm.avail_in = 0;
+        state->x.pos += offset;
+        return state->x.pos;
+    }
+
+    /* calculate skip amount, rewinding if needed for back seek when reading */
+    if (offset < 0) {
+        if (state->mode != GZ_READ)         /* writing -- can't go backwards */
+            return -1;
+        offset += state->x.pos;
+        if (offset < 0)                     /* before start of file! */
+            return -1;
+        if (gzrewind(file) == -1)           /* rewind, then skip to offset */
+            return -1;
+    }
+
+    /* if reading, skip what's in output buffer (one less gzgetc() check) */
+    if (state->mode == GZ_READ) {
+        n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
+            (unsigned)offset : state->x.have;
+        state->x.have -= n;
+        state->x.next += n;
+        state->x.pos += n;
+        offset -= n;
+    }
+
+    /* request skip (if not zero) */
+    if (offset) {
+        state->seek = 1;
+        state->skip = offset;
+    }
+    return state->x.pos + offset;
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gzseek(file, offset, whence)
+    gzFile file;
+    z_off_t offset;
+    int whence;
+{
+    z_off64_t ret;
+
+    ret = gzseek64(file, (z_off64_t)offset, whence);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gztell64(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* return position */
+    return state->x.pos + (state->seek ? state->skip : 0);
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gztell(file)
+    gzFile file;
+{
+    z_off64_t ret;
+
+    ret = gztell64(file);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gzoffset64(file)
+    gzFile file;
+{
+    z_off64_t offset;
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* compute and return effective offset in file */
+    offset = LSEEK(state->fd, 0, SEEK_CUR);
+    if (offset == -1)
+        return -1;
+    if (state->mode == GZ_READ)             /* reading */
+        offset -= state->strm.avail_in;     /* don't count buffered input */
+    return offset;
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gzoffset(file)
+    gzFile file;
+{
+    z_off64_t ret;
+
+    ret = gzoffset64(file);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzeof(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return 0;
+
+    /* return end-of-file state */
+    return state->mode == GZ_READ ? state->past : 0;
+}
+
+/* -- see zlib.h -- */
+const char * ZEXPORT gzerror(file, errnum)
+    gzFile file;
+    int *errnum;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return NULL;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return NULL;
+
+    /* return error information */
+    if (errnum != NULL)
+        *errnum = state->err;
+    return state->err == Z_MEM_ERROR ? "out of memory" :
+                                       (state->msg == NULL ? "" : state->msg);
+}
+
+/* -- see zlib.h -- */
+void ZEXPORT gzclearerr(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return;
+
+    /* clear error and end-of-file */
+    if (state->mode == GZ_READ) {
+        state->eof = 0;
+        state->past = 0;
+    }
+    gz_error(state, Z_OK, NULL);
+}
+
+/* Create an error message in allocated memory and set state->err and
+   state->msg accordingly.  Free any previous error message already there.  Do
+   not try to free or allocate space if the error is Z_MEM_ERROR (out of
+   memory).  Simply save the error message as a static string.  If there is an
+   allocation failure constructing the error message, then convert the error to
+   out of memory. */
+void ZLIB_INTERNAL gz_error(state, err, msg)
+    gz_statep state;
+    int err;
+    const char *msg;
+{
+    /* free previously allocated message and clear */
+    if (state->msg != NULL) {
+        if (state->err != Z_MEM_ERROR)
+            free(state->msg);
+        state->msg = NULL;
+    }
+
+    /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
+    if (err != Z_OK && err != Z_BUF_ERROR)
+        state->x.have = 0;
+
+    /* set error code, and if no message, then done */
+    state->err = err;
+    if (msg == NULL)
+        return;
+
+    /* for an out of memory error, return literal string when requested */
+    if (err == Z_MEM_ERROR)
+        return;
+
+    /* construct error message with path */
+    if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
+            NULL) {
+        state->err = Z_MEM_ERROR;
+        return;
+    }
+#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
+    (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
+                   "%s%s%s", state->path, ": ", msg);
+#else
+    strcpy(state->msg, state->path);
+    strcat(state->msg, ": ");
+    strcat(state->msg, msg);
+#endif
+}
+
+#ifndef INT_MAX
+/* portably return maximum value for an int (when limits.h presumed not
+   available) -- we need to do this to cover cases where 2's complement not
+   used, since C standard permits 1's complement and sign-bit representations,
+   otherwise we could just use ((unsigned)-1) >> 1 */
+unsigned ZLIB_INTERNAL gz_intmax()
+{
+    unsigned p, q;
+
+    p = 1;
+    do {
+        q = p;
+        p <<= 1;
+        p++;
+    } while (p > q);
+    return q >> 1;
+}
+#endif
diff --git a/xs/src/png/zlib/gzread.c b/xs/src/png/zlib/gzread.c
new file mode 100644
index 000000000..956b91ea7
--- /dev/null
+++ b/xs/src/png/zlib/gzread.c
@@ -0,0 +1,654 @@
+/* gzread.c -- zlib functions for reading gzip files
+ * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
+local int gz_avail OF((gz_statep));
+local int gz_look OF((gz_statep));
+local int gz_decomp OF((gz_statep));
+local int gz_fetch OF((gz_statep));
+local int gz_skip OF((gz_statep, z_off64_t));
+local z_size_t gz_read OF((gz_statep, voidp, z_size_t));
+
+/* Use read() to load a buffer -- return -1 on error, otherwise 0.  Read from
+   state->fd, and update state->eof, state->err, and state->msg as appropriate.
+   This function needs to loop on read(), since read() is not guaranteed to
+   read the number of bytes requested, depending on the type of descriptor. */
+local int gz_load(state, buf, len, have)
+    gz_statep state;
+    unsigned char *buf;
+    unsigned len;
+    unsigned *have;
+{
+    int ret;
+    unsigned get, max = ((unsigned)-1 >> 2) + 1;
+
+    *have = 0;
+    do {
+        get = len - *have;
+        if (get > max)
+            get = max;
+        ret = read(state->fd, buf + *have, get);
+        if (ret <= 0)
+            break;
+        *have += (unsigned)ret;
+    } while (*have < len);
+    if (ret < 0) {
+        gz_error(state, Z_ERRNO, zstrerror());
+        return -1;
+    }
+    if (ret == 0)
+        state->eof = 1;
+    return 0;
+}
+
+/* Load up input buffer and set eof flag if last data loaded -- return -1 on
+   error, 0 otherwise.  Note that the eof flag is set when the end of the input
+   file is reached, even though there may be unused data in the buffer.  Once
+   that data has been used, no more attempts will be made to read the file.
+   If strm->avail_in != 0, then the current data is moved to the beginning of
+   the input buffer, and then the remainder of the buffer is loaded with the
+   available data from the input file. */
+local int gz_avail(state)
+    gz_statep state;
+{
+    unsigned got;
+    z_streamp strm = &(state->strm);
+
+    if (state->err != Z_OK && state->err != Z_BUF_ERROR)
+        return -1;
+    if (state->eof == 0) {
+        if (strm->avail_in) {       /* copy what's there to the start */
+            unsigned char *p = state->in;
+            unsigned const char *q = strm->next_in;
+            unsigned n = strm->avail_in;
+            do {
+                *p++ = *q++;
+            } while (--n);
+        }
+        if (gz_load(state, state->in + strm->avail_in,
+                    state->size - strm->avail_in, &got) == -1)
+            return -1;
+        strm->avail_in += got;
+        strm->next_in = state->in;
+    }
+    return 0;
+}
+
+/* Look for gzip header, set up for inflate or copy.  state->x.have must be 0.
+   If this is the first time in, allocate required memory.  state->how will be
+   left unchanged if there is no more input data available, will be set to COPY
+   if there is no gzip header and direct copying will be performed, or it will
+   be set to GZIP for decompression.  If direct copying, then leftover input
+   data from the input buffer will be copied to the output buffer.  In that
+   case, all further file reads will be directly to either the output buffer or
+   a user buffer.  If decompressing, the inflate state will be initialized.
+   gz_look() will return 0 on success or -1 on failure. */
+local int gz_look(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    /* allocate read buffers and inflate memory */
+    if (state->size == 0) {
+        /* allocate buffers */
+        state->in = (unsigned char *)malloc(state->want);
+        state->out = (unsigned char *)malloc(state->want << 1);
+        if (state->in == NULL || state->out == NULL) {
+            free(state->out);
+            free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        state->size = state->want;
+
+        /* allocate inflate memory */
+        state->strm.zalloc = Z_NULL;
+        state->strm.zfree = Z_NULL;
+        state->strm.opaque = Z_NULL;
+        state->strm.avail_in = 0;
+        state->strm.next_in = Z_NULL;
+        if (inflateInit2(&(state->strm), 15 + 16) != Z_OK) {    /* gunzip */
+            free(state->out);
+            free(state->in);
+            state->size = 0;
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+    }
+
+    /* get at least the magic bytes in the input buffer */
+    if (strm->avail_in < 2) {
+        if (gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0)
+            return 0;
+    }
+
+    /* look for gzip magic bytes -- if there, do gzip decoding (note: there is
+       a logical dilemma here when considering the case of a partially written
+       gzip file, to wit, if a single 31 byte is written, then we cannot tell
+       whether this is a single-byte file, or just a partially written gzip
+       file -- for here we assume that if a gzip file is being written, then
+       the header will be written in a single operation, so that reading a
+       single byte is sufficient indication that it is not a gzip file) */
+    if (strm->avail_in > 1 &&
+            strm->next_in[0] == 31 && strm->next_in[1] == 139) {
+        inflateReset(strm);
+        state->how = GZIP;
+        state->direct = 0;
+        return 0;
+    }
+
+    /* no gzip header -- if we were decoding gzip before, then this is trailing
+       garbage.  Ignore the trailing garbage and finish. */
+    if (state->direct == 0) {
+        strm->avail_in = 0;
+        state->eof = 1;
+        state->x.have = 0;
+        return 0;
+    }
+
+    /* doing raw i/o, copy any leftover input to output -- this assumes that
+       the output buffer is larger than the input buffer, which also assures
+       space for gzungetc() */
+    state->x.next = state->out;
+    if (strm->avail_in) {
+        memcpy(state->x.next, strm->next_in, strm->avail_in);
+        state->x.have = strm->avail_in;
+        strm->avail_in = 0;
+    }
+    state->how = COPY;
+    state->direct = 1;
+    return 0;
+}
+
+/* Decompress from input to the provided next_out and avail_out in the state.
+   On return, state->x.have and state->x.next point to the just decompressed
+   data.  If the gzip stream completes, state->how is reset to LOOK to look for
+   the next gzip stream or raw data, once state->x.have is depleted.  Returns 0
+   on success, -1 on failure. */
+local int gz_decomp(state)
+    gz_statep state;
+{
+    int ret = Z_OK;
+    unsigned had;
+    z_streamp strm = &(state->strm);
+
+    /* fill output buffer up to end of deflate stream */
+    had = strm->avail_out;
+    do {
+        /* get more input for inflate() */
+        if (strm->avail_in == 0 && gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0) {
+            gz_error(state, Z_BUF_ERROR, "unexpected end of file");
+            break;
+        }
+
+        /* decompress and handle errors */
+        ret = inflate(strm, Z_NO_FLUSH);
+        if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
+            gz_error(state, Z_STREAM_ERROR,
+                     "internal error: inflate stream corrupt");
+            return -1;
+        }
+        if (ret == Z_MEM_ERROR) {
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        if (ret == Z_DATA_ERROR) {              /* deflate stream invalid */
+            gz_error(state, Z_DATA_ERROR,
+                     strm->msg == NULL ? "compressed data error" : strm->msg);
+            return -1;
+        }
+    } while (strm->avail_out && ret != Z_STREAM_END);
+
+    /* update available output */
+    state->x.have = had - strm->avail_out;
+    state->x.next = strm->next_out - state->x.have;
+
+    /* if the gzip stream completed successfully, look for another */
+    if (ret == Z_STREAM_END)
+        state->how = LOOK;
+
+    /* good decompression */
+    return 0;
+}
+
+/* Fetch data and put it in the output buffer.  Assumes state->x.have is 0.
+   Data is either copied from the input file or decompressed from the input
+   file depending on state->how.  If state->how is LOOK, then a gzip header is
+   looked for to determine whether to copy or decompress.  Returns -1 on error,
+   otherwise 0.  gz_fetch() will leave state->how as COPY or GZIP unless the
+   end of the input file has been reached and all data has been processed.  */
+local int gz_fetch(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    do {
+        switch(state->how) {
+        case LOOK:      /* -> LOOK, COPY (only if never GZIP), or GZIP */
+            if (gz_look(state) == -1)
+                return -1;
+            if (state->how == LOOK)
+                return 0;
+            break;
+        case COPY:      /* -> COPY */
+            if (gz_load(state, state->out, state->size << 1, &(state->x.have))
+                    == -1)
+                return -1;
+            state->x.next = state->out;
+            return 0;
+        case GZIP:      /* -> GZIP or LOOK (if end of gzip stream) */
+            strm->avail_out = state->size << 1;
+            strm->next_out = state->out;
+            if (gz_decomp(state) == -1)
+                return -1;
+        }
+    } while (state->x.have == 0 && (!state->eof || strm->avail_in));
+    return 0;
+}
+
+/* Skip len uncompressed bytes of output.  Return -1 on error, 0 on success. */
+local int gz_skip(state, len)
+    gz_statep state;
+    z_off64_t len;
+{
+    unsigned n;
+
+    /* skip over len bytes or reach end-of-file, whichever comes first */
+    while (len)
+        /* skip over whatever is in output buffer */
+        if (state->x.have) {
+            n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > len ?
+                (unsigned)len : state->x.have;
+            state->x.have -= n;
+            state->x.next += n;
+            state->x.pos += n;
+            len -= n;
+        }
+
+        /* output buffer empty -- return if we're at the end of the input */
+        else if (state->eof && state->strm.avail_in == 0)
+            break;
+
+        /* need more data to skip -- load up output buffer */
+        else {
+            /* get more output, looking for header if required */
+            if (gz_fetch(state) == -1)
+                return -1;
+        }
+    return 0;
+}
+
+/* Read len bytes into buf from file, or less than len up to the end of the
+   input.  Return the number of bytes read.  If zero is returned, either the
+   end of file was reached, or there was an error.  state->err must be
+   consulted in that case to determine which. */
+local z_size_t gz_read(state, buf, len)
+    gz_statep state;
+    voidp buf;
+    z_size_t len;
+{
+    z_size_t got;
+    unsigned n;
+
+    /* if len is zero, avoid unnecessary operations */
+    if (len == 0)
+        return 0;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* get len bytes to buf, or less than len if at the end */
+    got = 0;
+    do {
+        /* set n to the maximum amount of len that fits in an unsigned int */
+        n = -1;
+        if (n > len)
+            n = len;
+
+        /* first just try copying data from the output buffer */
+        if (state->x.have) {
+            if (state->x.have < n)
+                n = state->x.have;
+            memcpy(buf, state->x.next, n);
+            state->x.next += n;
+            state->x.have -= n;
+        }
+
+        /* output buffer empty -- return if we're at the end of the input */
+        else if (state->eof && state->strm.avail_in == 0) {
+            state->past = 1;        /* tried to read past end */
+            break;
+        }
+
+        /* need output data -- for small len or new stream load up our output
+           buffer */
+        else if (state->how == LOOK || n < (state->size << 1)) {
+            /* get more output, looking for header if required */
+            if (gz_fetch(state) == -1)
+                return 0;
+            continue;       /* no progress yet -- go back to copy above */
+            /* the copy above assures that we will leave with space in the
+               output buffer, allowing at least one gzungetc() to succeed */
+        }
+
+        /* large len -- read directly into user buffer */
+        else if (state->how == COPY) {      /* read directly */
+            if (gz_load(state, (unsigned char *)buf, n, &n) == -1)
+                return 0;
+        }
+
+        /* large len -- decompress directly into user buffer */
+        else {  /* state->how == GZIP */
+            state->strm.avail_out = n;
+            state->strm.next_out = (unsigned char *)buf;
+            if (gz_decomp(state) == -1)
+                return 0;
+            n = state->x.have;
+            state->x.have = 0;
+        }
+
+        /* update progress */
+        len -= n;
+        buf = (char *)buf + n;
+        got += n;
+        state->x.pos += n;
+    } while (len);
+
+    /* return number of bytes read into user buffer */
+    return got;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzread(file, buf, len)
+    gzFile file;
+    voidp buf;
+    unsigned len;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+            (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* since an int is returned, make sure len fits in one, otherwise return
+       with an error (this avoids a flaw in the interface) */
+    if ((int)len < 0) {
+        gz_error(state, Z_STREAM_ERROR, "request does not fit in an int");
+        return -1;
+    }
+
+    /* read len or fewer bytes to buf */
+    len = gz_read(state, buf, len);
+
+    /* check for an error */
+    if (len == 0 && state->err != Z_OK && state->err != Z_BUF_ERROR)
+        return -1;
+
+    /* return the number of bytes read (this is assured to fit in an int) */
+    return (int)len;
+}
+
+/* -- see zlib.h -- */
+z_size_t ZEXPORT gzfread(buf, size, nitems, file)
+    voidp buf;
+    z_size_t size;
+    z_size_t nitems;
+    gzFile file;
+{
+    z_size_t len;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+            (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return 0;
+
+    /* compute bytes to read -- error on overflow */
+    len = nitems * size;
+    if (size && len / size != nitems) {
+        gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
+        return 0;
+    }
+
+    /* read len or fewer bytes to buf, return the number of full items read */
+    return len ? gz_read(state, buf, len) / size : 0;
+}
+
+/* -- see zlib.h -- */
+#ifdef Z_PREFIX_SET
+#  undef z_gzgetc
+#else
+#  undef gzgetc
+#endif
+int ZEXPORT gzgetc(file)
+    gzFile file;
+{
+    int ret;
+    unsigned char buf[1];
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+        (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* try output buffer (no need to check for skip request) */
+    if (state->x.have) {
+        state->x.have--;
+        state->x.pos++;
+        return *(state->x.next)++;
+    }
+
+    /* nothing there -- try gz_read() */
+    ret = gz_read(state, buf, 1);
+    return ret < 1 ? -1 : buf[0];
+}
+
+int ZEXPORT gzgetc_(file)
+gzFile file;
+{
+    return gzgetc(file);
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzungetc(c, file)
+    int c;
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+        (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* can't push EOF */
+    if (c < 0)
+        return -1;
+
+    /* if output buffer empty, put byte at end (allows more pushing) */
+    if (state->x.have == 0) {
+        state->x.have = 1;
+        state->x.next = state->out + (state->size << 1) - 1;
+        state->x.next[0] = (unsigned char)c;
+        state->x.pos--;
+        state->past = 0;
+        return c;
+    }
+
+    /* if no room, give up (must have already done a gzungetc()) */
+    if (state->x.have == (state->size << 1)) {
+        gz_error(state, Z_DATA_ERROR, "out of room to push characters");
+        return -1;
+    }
+
+    /* slide output data if needed and insert byte before existing data */
+    if (state->x.next == state->out) {
+        unsigned char *src = state->out + state->x.have;
+        unsigned char *dest = state->out + (state->size << 1);
+        while (src > state->out)
+            *--dest = *--src;
+        state->x.next = dest;
+    }
+    state->x.have++;
+    state->x.next--;
+    state->x.next[0] = (unsigned char)c;
+    state->x.pos--;
+    state->past = 0;
+    return c;
+}
+
+/* -- see zlib.h -- */
+char * ZEXPORT gzgets(file, buf, len)
+    gzFile file;
+    char *buf;
+    int len;
+{
+    unsigned left, n;
+    char *str;
+    unsigned char *eol;
+    gz_statep state;
+
+    /* check parameters and get internal structure */
+    if (file == NULL || buf == NULL || len < 1)
+        return NULL;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+        (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return NULL;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return NULL;
+    }
+
+    /* copy output bytes up to new line or len - 1, whichever comes first --
+       append a terminating zero to the string (we don't check for a zero in
+       the contents, let the user worry about that) */
+    str = buf;
+    left = (unsigned)len - 1;
+    if (left) do {
+        /* assure that something is in the output buffer */
+        if (state->x.have == 0 && gz_fetch(state) == -1)
+            return NULL;                /* error */
+        if (state->x.have == 0) {       /* end of file */
+            state->past = 1;            /* read past end */
+            break;                      /* return what we have */
+        }
+
+        /* look for end-of-line in current output buffer */
+        n = state->x.have > left ? left : state->x.have;
+        eol = (unsigned char *)memchr(state->x.next, '\n', n);
+        if (eol != NULL)
+            n = (unsigned)(eol - state->x.next) + 1;
+
+        /* copy through end-of-line, or remainder if not found */
+        memcpy(buf, state->x.next, n);
+        state->x.have -= n;
+        state->x.next += n;
+        state->x.pos += n;
+        left -= n;
+        buf += n;
+    } while (left && eol == NULL);
+
+    /* return terminated string, or if nothing, end of file */
+    if (buf == str)
+        return NULL;
+    buf[0] = 0;
+    return str;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzdirect(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* if the state is not known, but we can find out, then do so (this is
+       mainly for right after a gzopen() or gzdopen()) */
+    if (state->mode == GZ_READ && state->how == LOOK && state->x.have == 0)
+        (void)gz_look(state);
+
+    /* return 1 if transparent, 0 if processing a gzip stream */
+    return state->direct;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_r(file)
+    gzFile file;
+{
+    int ret, err;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're reading */
+    if (state->mode != GZ_READ)
+        return Z_STREAM_ERROR;
+
+    /* free memory and close file */
+    if (state->size) {
+        inflateEnd(&(state->strm));
+        free(state->out);
+        free(state->in);
+    }
+    err = state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK;
+    gz_error(state, Z_OK, NULL);
+    free(state->path);
+    ret = close(state->fd);
+    free(state);
+    return ret ? Z_ERRNO : err;
+}
diff --git a/xs/src/png/zlib/gzwrite.c b/xs/src/png/zlib/gzwrite.c
new file mode 100644
index 000000000..c7b5651d7
--- /dev/null
+++ b/xs/src/png/zlib/gzwrite.c
@@ -0,0 +1,665 @@
+/* gzwrite.c -- zlib functions for writing gzip files
+ * Copyright (C) 2004-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_init OF((gz_statep));
+local int gz_comp OF((gz_statep, int));
+local int gz_zero OF((gz_statep, z_off64_t));
+local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
+
+/* Initialize state for writing a gzip file.  Mark initialization by setting
+   state->size to non-zero.  Return -1 on a memory allocation failure, or 0 on
+   success. */
+local int gz_init(state)
+    gz_statep state;
+{
+    int ret;
+    z_streamp strm = &(state->strm);
+
+    /* allocate input buffer (double size for gzprintf) */
+    state->in = (unsigned char *)malloc(state->want << 1);
+    if (state->in == NULL) {
+        gz_error(state, Z_MEM_ERROR, "out of memory");
+        return -1;
+    }
+
+    /* only need output buffer and deflate state if compressing */
+    if (!state->direct) {
+        /* allocate output buffer */
+        state->out = (unsigned char *)malloc(state->want);
+        if (state->out == NULL) {
+            free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+
+        /* allocate deflate memory, set up for gzip compression */
+        strm->zalloc = Z_NULL;
+        strm->zfree = Z_NULL;
+        strm->opaque = Z_NULL;
+        ret = deflateInit2(strm, state->level, Z_DEFLATED,
+                           MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
+        if (ret != Z_OK) {
+            free(state->out);
+            free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        strm->next_in = NULL;
+    }
+
+    /* mark state as initialized */
+    state->size = state->want;
+
+    /* initialize write buffer if compressing */
+    if (!state->direct) {
+        strm->avail_out = state->size;
+        strm->next_out = state->out;
+        state->x.next = strm->next_out;
+    }
+    return 0;
+}
+
+/* Compress whatever is at avail_in and next_in and write to the output file.
+   Return -1 if there is an error writing to the output file or if gz_init()
+   fails to allocate memory, otherwise 0.  flush is assumed to be a valid
+   deflate() flush value.  If flush is Z_FINISH, then the deflate() state is
+   reset to start a new gzip stream.  If gz->direct is true, then simply write
+   to the output file without compressing, and ignore flush. */
+local int gz_comp(state, flush)
+    gz_statep state;
+    int flush;
+{
+    int ret, writ;
+    unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
+    z_streamp strm = &(state->strm);
+
+    /* allocate memory if this is the first time through */
+    if (state->size == 0 && gz_init(state) == -1)
+        return -1;
+
+    /* write directly if requested */
+    if (state->direct) {
+        while (strm->avail_in) {
+            put = strm->avail_in > max ? max : strm->avail_in;
+            writ = write(state->fd, strm->next_in, put);
+            if (writ < 0) {
+                gz_error(state, Z_ERRNO, zstrerror());
+                return -1;
+            }
+            strm->avail_in -= (unsigned)writ;
+            strm->next_in += writ;
+        }
+        return 0;
+    }
+
+    /* run deflate() on provided input until it produces no more output */
+    ret = Z_OK;
+    do {
+        /* write out current buffer contents if full, or if flushing, but if
+           doing Z_FINISH then don't write until we get to Z_STREAM_END */
+        if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
+            (flush != Z_FINISH || ret == Z_STREAM_END))) {
+            while (strm->next_out > state->x.next) {
+                put = strm->next_out - state->x.next > (int)max ? max :
+                      (unsigned)(strm->next_out - state->x.next);
+                writ = write(state->fd, state->x.next, put);
+                if (writ < 0) {
+                    gz_error(state, Z_ERRNO, zstrerror());
+                    return -1;
+                }
+                state->x.next += writ;
+            }
+            if (strm->avail_out == 0) {
+                strm->avail_out = state->size;
+                strm->next_out = state->out;
+                state->x.next = state->out;
+            }
+        }
+
+        /* compress */
+        have = strm->avail_out;
+        ret = deflate(strm, flush);
+        if (ret == Z_STREAM_ERROR) {
+            gz_error(state, Z_STREAM_ERROR,
+                      "internal error: deflate stream corrupt");
+            return -1;
+        }
+        have -= strm->avail_out;
+    } while (have);
+
+    /* if that completed a deflate stream, allow another to start */
+    if (flush == Z_FINISH)
+        deflateReset(strm);
+
+    /* all done, no errors */
+    return 0;
+}
+
+/* Compress len zeros to output.  Return -1 on a write error or memory
+   allocation failure by gz_comp(), or 0 on success. */
+local int gz_zero(state, len)
+    gz_statep state;
+    z_off64_t len;
+{
+    int first;
+    unsigned n;
+    z_streamp strm = &(state->strm);
+
+    /* consume whatever's left in the input buffer */
+    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+        return -1;
+
+    /* compress len zeros (len guaranteed > 0) */
+    first = 1;
+    while (len) {
+        n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
+            (unsigned)len : state->size;
+        if (first) {
+            memset(state->in, 0, n);
+            first = 0;
+        }
+        strm->avail_in = n;
+        strm->next_in = state->in;
+        state->x.pos += n;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return -1;
+        len -= n;
+    }
+    return 0;
+}
+
+/* Write len bytes from buf to file.  Return the number of bytes written.  If
+   the returned value is less than len, then there was an error. */
+local z_size_t gz_write(state, buf, len)
+    gz_statep state;
+    voidpc buf;
+    z_size_t len;
+{
+    z_size_t put = len;
+
+    /* if len is zero, avoid unnecessary operations */
+    if (len == 0)
+        return 0;
+
+    /* allocate memory if this is the first time through */
+    if (state->size == 0 && gz_init(state) == -1)
+        return 0;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* for small len, copy to input buffer, otherwise compress directly */
+    if (len < state->size) {
+        /* copy to input buffer, compress when full */
+        do {
+            unsigned have, copy;
+
+            if (state->strm.avail_in == 0)
+                state->strm.next_in = state->in;
+            have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
+                              state->in);
+            copy = state->size - have;
+            if (copy > len)
+                copy = len;
+            memcpy(state->in + have, buf, copy);
+            state->strm.avail_in += copy;
+            state->x.pos += copy;
+            buf = (const char *)buf + copy;
+            len -= copy;
+            if (len && gz_comp(state, Z_NO_FLUSH) == -1)
+                return 0;
+        } while (len);
+    }
+    else {
+        /* consume whatever's left in the input buffer */
+        if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+            return 0;
+
+        /* directly compress user buffer to file */
+        state->strm.next_in = (z_const Bytef *)buf;
+        do {
+            unsigned n = (unsigned)-1;
+            if (n > len)
+                n = len;
+            state->strm.avail_in = n;
+            state->x.pos += n;
+            if (gz_comp(state, Z_NO_FLUSH) == -1)
+                return 0;
+            len -= n;
+        } while (len);
+    }
+
+    /* input was all buffered or compressed */
+    return put;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzwrite(file, buf, len)
+    gzFile file;
+    voidpc buf;
+    unsigned len;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* since an int is returned, make sure len fits in one, otherwise return
+       with an error (this avoids a flaw in the interface) */
+    if ((int)len < 0) {
+        gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
+        return 0;
+    }
+
+    /* write len bytes from buf (the return value will fit in an int) */
+    return (int)gz_write(state, buf, len);
+}
+
+/* -- see zlib.h -- */
+z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
+    voidpc buf;
+    z_size_t size;
+    z_size_t nitems;
+    gzFile file;
+{
+    z_size_t len;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* compute bytes to read -- error on overflow */
+    len = nitems * size;
+    if (size && len / size != nitems) {
+        gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
+        return 0;
+    }
+
+    /* write len bytes to buf, return the number of full items written */
+    return len ? gz_write(state, buf, len) / size : 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzputc(file, c)
+    gzFile file;
+    int c;
+{
+    unsigned have;
+    unsigned char buf[1];
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return -1;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* try writing to input buffer for speed (state->size == 0 if buffer not
+       initialized) */
+    if (state->size) {
+        if (strm->avail_in == 0)
+            strm->next_in = state->in;
+        have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
+        if (have < state->size) {
+            state->in[have] = (unsigned char)c;
+            strm->avail_in++;
+            state->x.pos++;
+            return c & 0xff;
+        }
+    }
+
+    /* no room in buffer or not initialized, use gz_write() */
+    buf[0] = (unsigned char)c;
+    if (gz_write(state, buf, 1) != 1)
+        return -1;
+    return c & 0xff;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzputs(file, str)
+    gzFile file;
+    const char *str;
+{
+    int ret;
+    z_size_t len;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return -1;
+
+    /* write string */
+    len = strlen(str);
+    ret = gz_write(state, str, len);
+    return ret == 0 && len != 0 ? -1 : ret;
+}
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#include <stdarg.h>
+
+/* -- see zlib.h -- */
+int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
+{
+    int len;
+    unsigned left;
+    char *next;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* make sure we have some buffer space */
+    if (state->size == 0 && gz_init(state) == -1)
+        return state->err;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->err;
+    }
+
+    /* do the printf() into the input buffer, put length in len -- the input
+       buffer is double-sized just for this function, so there is guaranteed to
+       be state->size bytes available after the current contents */
+    if (strm->avail_in == 0)
+        strm->next_in = state->in;
+    next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
+    next[state->size - 1] = 0;
+#ifdef NO_vsnprintf
+#  ifdef HAS_vsprintf_void
+    (void)vsprintf(next, format, va);
+    for (len = 0; len < state->size; len++)
+        if (next[len] == 0) break;
+#  else
+    len = vsprintf(next, format, va);
+#  endif
+#else
+#  ifdef HAS_vsnprintf_void
+    (void)vsnprintf(next, state->size, format, va);
+    len = strlen(next);
+#  else
+    len = vsnprintf(next, state->size, format, va);
+#  endif
+#endif
+
+    /* check that printf() results fit in buffer */
+    if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
+        return 0;
+
+    /* update buffer and position, compress first half if past that */
+    strm->avail_in += (unsigned)len;
+    state->x.pos += len;
+    if (strm->avail_in >= state->size) {
+        left = strm->avail_in - state->size;
+        strm->avail_in = state->size;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return state->err;
+        memcpy(state->in, state->in + state->size, left);
+        strm->next_in = state->in;
+        strm->avail_in = left;
+    }
+    return len;
+}
+
+int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
+{
+    va_list va;
+    int ret;
+
+    va_start(va, format);
+    ret = gzvprintf(file, format, va);
+    va_end(va);
+    return ret;
+}
+
+#else /* !STDC && !Z_HAVE_STDARG_H */
+
+/* -- see zlib.h -- */
+int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+                       a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
+    gzFile file;
+    const char *format;
+    int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
+{
+    unsigned len, left;
+    char *next;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that can really pass pointer in ints */
+    if (sizeof(int) != sizeof(void *))
+        return Z_STREAM_ERROR;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* make sure we have some buffer space */
+    if (state->size == 0 && gz_init(state) == -1)
+        return state->error;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->error;
+    }
+
+    /* do the printf() into the input buffer, put length in len -- the input
+       buffer is double-sized just for this function, so there is guaranteed to
+       be state->size bytes available after the current contents */
+    if (strm->avail_in == 0)
+        strm->next_in = state->in;
+    next = (char *)(strm->next_in + strm->avail_in);
+    next[state->size - 1] = 0;
+#ifdef NO_snprintf
+#  ifdef HAS_sprintf_void
+    sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
+            a13, a14, a15, a16, a17, a18, a19, a20);
+    for (len = 0; len < size; len++)
+        if (next[len] == 0)
+            break;
+#  else
+    len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
+                  a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#  endif
+#else
+#  ifdef HAS_snprintf_void
+    snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
+             a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+    len = strlen(next);
+#  else
+    len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
+                   a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#  endif
+#endif
+
+    /* check that printf() results fit in buffer */
+    if (len == 0 || len >= state->size || next[state->size - 1] != 0)
+        return 0;
+
+    /* update buffer and position, compress first half if past that */
+    strm->avail_in += len;
+    state->x.pos += len;
+    if (strm->avail_in >= state->size) {
+        left = strm->avail_in - state->size;
+        strm->avail_in = state->size;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return state->err;
+        memcpy(state->in, state->in + state->size, left);
+        strm->next_in = state->in;
+        strm->avail_in = left;
+    }
+    return (int)len;
+}
+
+#endif
+
+/* -- see zlib.h -- */
+int ZEXPORT gzflush(file, flush)
+    gzFile file;
+    int flush;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* check flush parameter */
+    if (flush < 0 || flush > Z_FINISH)
+        return Z_STREAM_ERROR;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->err;
+    }
+
+    /* compress remaining data with requested flush */
+    (void)gz_comp(state, flush);
+    return state->err;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzsetparams(file, level, strategy)
+    gzFile file;
+    int level;
+    int strategy;
+{
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* if no change is requested, then do nothing */
+    if (level == state->level && strategy == state->strategy)
+        return Z_OK;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->err;
+    }
+
+    /* change compression parameters for subsequent input */
+    if (state->size) {
+        /* flush previous input with previous parameters before changing */
+        if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
+            return state->err;
+        deflateParams(strm, level, strategy);
+    }
+    state->level = level;
+    state->strategy = strategy;
+    return Z_OK;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_w(file)
+    gzFile file;
+{
+    int ret = Z_OK;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're writing */
+    if (state->mode != GZ_WRITE)
+        return Z_STREAM_ERROR;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            ret = state->err;
+    }
+
+    /* flush, free memory, and close file */
+    if (gz_comp(state, Z_FINISH) == -1)
+        ret = state->err;
+    if (state->size) {
+        if (!state->direct) {
+            (void)deflateEnd(&(state->strm));
+            free(state->out);
+        }
+        free(state->in);
+    }
+    gz_error(state, Z_OK, NULL);
+    free(state->path);
+    if (close(state->fd) == -1)
+        ret = Z_ERRNO;
+    free(state);
+    return ret;
+}
diff --git a/xs/src/png/zlib/infback.c b/xs/src/png/zlib/infback.c
new file mode 100644
index 000000000..59679ecbf
--- /dev/null
+++ b/xs/src/png/zlib/infback.c
@@ -0,0 +1,640 @@
+/* infback.c -- inflate using a call-back interface
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+   This code is largely copied from inflate.c.  Normally either infback.o or
+   inflate.o would be linked into an application--not both.  The interface
+   with inffast.c is retained so that optimized assembler-coded versions of
+   inflate_fast() can be used with either inflate.c or infback.c.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+/* function prototypes */
+local void fixedtables OF((struct inflate_state FAR *state));
+
+/*
+   strm provides memory allocation functions in zalloc and zfree, or
+   Z_NULL to use the library memory allocation functions.
+
+   windowBits is in the range 8..15, and window is a user-supplied
+   window and output buffer that is 2**windowBits bytes.
+ */
+int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size)
+z_streamp strm;
+int windowBits;
+unsigned char FAR *window;
+const char *version;
+int stream_size;
+{
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL || window == Z_NULL ||
+        windowBits < 8 || windowBits > 15)
+        return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+    strm->zfree = zcfree;
+#endif
+    state = (struct inflate_state FAR *)ZALLOC(strm, 1,
+                                               sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (struct internal_state FAR *)state;
+    state->dmax = 32768U;
+    state->wbits = (uInt)windowBits;
+    state->wsize = 1U << windowBits;
+    state->window = window;
+    state->wnext = 0;
+    state->whave = 0;
+    return Z_OK;
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state->lens[sym++] = 8;
+        while (sym < 256) state->lens[sym++] = 9;
+        while (sym < 280) state->lens[sym++] = 7;
+        while (sym < 288) state->lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state->lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
+}
+
+/* Macros for inflateBack(): */
+
+/* Load returned state from inflate_fast() */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Set state from registers for inflate_fast() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Assure that some input is available.  If input is requested, but denied,
+   then return a Z_BUF_ERROR from inflateBack(). */
+#define PULL() \
+    do { \
+        if (have == 0) { \
+            have = in(in_desc, &next); \
+            if (have == 0) { \
+                next = Z_NULL; \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflateBack()
+   with an error if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        PULL(); \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflateBack() with
+   an error. */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Assure that some output space is available, by writing out the window
+   if it's full.  If the write fails, return from inflateBack() with a
+   Z_BUF_ERROR. */
+#define ROOM() \
+    do { \
+        if (left == 0) { \
+            put = state->window; \
+            left = state->wsize; \
+            state->whave = left; \
+            if (out(out_desc, put, left)) { \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/*
+   strm provides the memory allocation functions and window buffer on input,
+   and provides information on the unused input on return.  For Z_DATA_ERROR
+   returns, strm will also provide an error message.
+
+   in() and out() are the call-back input and output functions.  When
+   inflateBack() needs more input, it calls in().  When inflateBack() has
+   filled the window with output, or when it completes with data in the
+   window, it calls out() to write out the data.  The application must not
+   change the provided input until in() is called again or inflateBack()
+   returns.  The application must not change the window/output buffer until
+   inflateBack() returns.
+
+   in() and out() are called with a descriptor parameter provided in the
+   inflateBack() call.  This parameter can be a structure that provides the
+   information required to do the read or write, as well as accumulated
+   information on the input and output such as totals and check values.
+
+   in() should return zero on failure.  out() should return non-zero on
+   failure.  If either in() or out() fails, than inflateBack() returns a
+   Z_BUF_ERROR.  strm->next_in can be checked for Z_NULL to see whether it
+   was in() or out() that caused in the error.  Otherwise,  inflateBack()
+   returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
+   error, or Z_MEM_ERROR if it could not allocate memory for the state.
+   inflateBack() can also return Z_STREAM_ERROR if the input parameters
+   are not correct, i.e. strm is Z_NULL or the state was not initialized.
+ */
+int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc)
+z_streamp strm;
+in_func in;
+void FAR *in_desc;
+out_func out;
+void FAR *out_desc;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    /* Check that the strm exists and that the state was initialized */
+    if (strm == Z_NULL || strm->state == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* Reset the state */
+    strm->msg = Z_NULL;
+    state->mode = TYPE;
+    state->last = 0;
+    state->whave = 0;
+    next = strm->next_in;
+    have = next != Z_NULL ? strm->avail_in : 0;
+    hold = 0;
+    bits = 0;
+    put = state->window;
+    left = state->wsize;
+
+    /* Inflate until end of block marked as last */
+    for (;;)
+        switch (state->mode) {
+        case TYPE:
+            /* determine and dispatch block type */
+            if (state->last) {
+                BYTEBITS();
+                state->mode = DONE;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables(state);
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = LEN;              /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+
+        case STORED:
+            /* get and verify stored block length */
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %u\n",
+                    state->length));
+            INITBITS();
+
+            /* copy stored block from input to output */
+            while (state->length != 0) {
+                copy = state->length;
+                PULL();
+                ROOM();
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            state->mode = TYPE;
+            break;
+
+        case TABLE:
+            /* get dynamic table entries descriptor */
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+
+            /* get code length code lengths (not a typo) */
+            state->have = 0;
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (code const FAR *)(state->next);
+            state->lenbits = 7;
+            ret = inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+
+            /* get length and distance code code lengths */
+            state->have = 0;
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = (unsigned)(state->lens[state->have - 1]);
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                state->mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftrees.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            state->lencode = (code const FAR *)(state->next);
+            state->lenbits = 9;
+            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (code const FAR *)(state->next);
+            state->distbits = 6;
+            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN;
+
+        case LEN:
+            /* use inflate_fast() if we have enough input and output */
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                if (state->whave < state->wsize)
+                    state->whave = state->wsize - left;
+                inflate_fast(strm, state->wsize);
+                LOAD();
+                break;
+            }
+
+            /* get a literal, length, or end-of-block code */
+            for (;;) {
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            state->length = (unsigned)here.val;
+
+            /* process literal */
+            if (here.op == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                ROOM();
+                *put++ = (unsigned char)(state->length);
+                left--;
+                state->mode = LEN;
+                break;
+            }
+
+            /* process end of block */
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                state->mode = TYPE;
+                break;
+            }
+
+            /* invalid code */
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+
+            /* length code -- get extra bits, if any */
+            state->extra = (unsigned)(here.op) & 15;
+            if (state->extra != 0) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            Tracevv((stderr, "inflate:         length %u\n", state->length));
+
+            /* get distance code */
+            for (;;) {
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)here.val;
+
+            /* get distance extra bits, if any */
+            state->extra = (unsigned)(here.op) & 15;
+            if (state->extra != 0) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            if (state->offset > state->wsize - (state->whave < state->wsize ?
+                                                left : 0)) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
+
+            /* copy match from window to output */
+            do {
+                ROOM();
+                copy = state->wsize - state->offset;
+                if (copy < left) {
+                    from = put + copy;
+                    copy = left - copy;
+                }
+                else {
+                    from = put - state->offset;
+                    copy = left;
+                }
+                if (copy > state->length) copy = state->length;
+                state->length -= copy;
+                left -= copy;
+                do {
+                    *put++ = *from++;
+                } while (--copy);
+            } while (state->length != 0);
+            break;
+
+        case DONE:
+            /* inflate stream terminated properly -- write leftover output */
+            ret = Z_STREAM_END;
+            if (left < state->wsize) {
+                if (out(out_desc, state->window, state->wsize - left))
+                    ret = Z_BUF_ERROR;
+            }
+            goto inf_leave;
+
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+
+        default:                /* can't happen, but makes compilers happy */
+            ret = Z_STREAM_ERROR;
+            goto inf_leave;
+        }
+
+    /* Return unused input */
+  inf_leave:
+    strm->next_in = next;
+    strm->avail_in = have;
+    return ret;
+}
+
+int ZEXPORT inflateBackEnd(strm)
+z_streamp strm;
+{
+    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+        return Z_STREAM_ERROR;
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
diff --git a/xs/src/png/zlib/inffast.c b/xs/src/png/zlib/inffast.c
new file mode 100644
index 000000000..0dbd1dbc0
--- /dev/null
+++ b/xs/src/png/zlib/inffast.c
@@ -0,0 +1,323 @@
+/* inffast.c -- fast decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef ASMINF
+#  pragma message("Assembler code may have bugs -- use at your own risk")
+#else
+
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
+
+   Entry assumptions:
+
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+void ZLIB_INTERNAL inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *in;      /* local strm->next_in */
+    z_const unsigned char FAR *last;    /* have enough input while in < last */
+    unsigned char FAR *out;     /* local strm->next_out */
+    unsigned char FAR *beg;     /* inflate()'s initial strm->next_out */
+    unsigned char FAR *end;     /* while out < end, enough space available */
+#ifdef INFLATE_STRICT
+    unsigned dmax;              /* maximum distance from zlib header */
+#endif
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned wnext;             /* window write index */
+    unsigned char FAR *window;  /* allocated sliding window, if wsize != 0 */
+    unsigned long hold;         /* local strm->hold */
+    unsigned bits;              /* local strm->bits */
+    code const FAR *lcode;      /* local strm->lencode */
+    code const FAR *dcode;      /* local strm->distcode */
+    unsigned lmask;             /* mask for first level of length codes */
+    unsigned dmask;             /* mask for first level of distance codes */
+    code here;                  /* retrieved table entry */
+    unsigned op;                /* code bits, operation, extra bits, or */
+                                /*  window position, window bytes to copy */
+    unsigned len;               /* match length, unused bytes */
+    unsigned dist;              /* match distance */
+    unsigned char FAR *from;    /* where to copy match from */
+
+    /* copy state to local variables */
+    state = (struct inflate_state FAR *)strm->state;
+    in = strm->next_in;
+    last = in + (strm->avail_in - 5);
+    out = strm->next_out;
+    beg = out - (start - strm->avail_out);
+    end = out + (strm->avail_out - 257);
+#ifdef INFLATE_STRICT
+    dmax = state->dmax;
+#endif
+    wsize = state->wsize;
+    whave = state->whave;
+    wnext = state->wnext;
+    window = state->window;
+    hold = state->hold;
+    bits = state->bits;
+    lcode = state->lencode;
+    dcode = state->distcode;
+    lmask = (1U << state->lenbits) - 1;
+    dmask = (1U << state->distbits) - 1;
+
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
+    do {
+        if (bits < 15) {
+            hold += (unsigned long)(*in++) << bits;
+            bits += 8;
+            hold += (unsigned long)(*in++) << bits;
+            bits += 8;
+        }
+        here = lcode[hold & lmask];
+      dolen:
+        op = (unsigned)(here.bits);
+        hold >>= op;
+        bits -= op;
+        op = (unsigned)(here.op);
+        if (op == 0) {                          /* literal */
+            Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                    "inflate:         literal '%c'\n" :
+                    "inflate:         literal 0x%02x\n", here.val));
+            *out++ = (unsigned char)(here.val);
+        }
+        else if (op & 16) {                     /* length base */
+            len = (unsigned)(here.val);
+            op &= 15;                           /* number of extra bits */
+            if (op) {
+                if (bits < op) {
+                    hold += (unsigned long)(*in++) << bits;
+                    bits += 8;
+                }
+                len += (unsigned)hold & ((1U << op) - 1);
+                hold >>= op;
+                bits -= op;
+            }
+            Tracevv((stderr, "inflate:         length %u\n", len));
+            if (bits < 15) {
+                hold += (unsigned long)(*in++) << bits;
+                bits += 8;
+                hold += (unsigned long)(*in++) << bits;
+                bits += 8;
+            }
+            here = dcode[hold & dmask];
+          dodist:
+            op = (unsigned)(here.bits);
+            hold >>= op;
+            bits -= op;
+            op = (unsigned)(here.op);
+            if (op & 16) {                      /* distance base */
+                dist = (unsigned)(here.val);
+                op &= 15;                       /* number of extra bits */
+                if (bits < op) {
+                    hold += (unsigned long)(*in++) << bits;
+                    bits += 8;
+                    if (bits < op) {
+                        hold += (unsigned long)(*in++) << bits;
+                        bits += 8;
+                    }
+                }
+                dist += (unsigned)hold & ((1U << op) - 1);
+#ifdef INFLATE_STRICT
+                if (dist > dmax) {
+                    strm->msg = (char *)"invalid distance too far back";
+                    state->mode = BAD;
+                    break;
+                }
+#endif
+                hold >>= op;
+                bits -= op;
+                Tracevv((stderr, "inflate:         distance %u\n", dist));
+                op = (unsigned)(out - beg);     /* max distance in output */
+                if (dist > op) {                /* see if copy from window */
+                    op = dist - op;             /* distance back in window */
+                    if (op > whave) {
+                        if (state->sane) {
+                            strm->msg =
+                                (char *)"invalid distance too far back";
+                            state->mode = BAD;
+                            break;
+                        }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                        if (len <= op - whave) {
+                            do {
+                                *out++ = 0;
+                            } while (--len);
+                            continue;
+                        }
+                        len -= op - whave;
+                        do {
+                            *out++ = 0;
+                        } while (--op > whave);
+                        if (op == 0) {
+                            from = out - dist;
+                            do {
+                                *out++ = *from++;
+                            } while (--len);
+                            continue;
+                        }
+#endif
+                    }
+                    from = window;
+                    if (wnext == 0) {           /* very common case */
+                        from += wsize - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    else if (wnext < op) {      /* wrap around window */
+                        from += wsize + wnext - op;
+                        op -= wnext;
+                        if (op < len) {         /* some from end of window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = window;
+                            if (wnext < len) {  /* some from start of window */
+                                op = wnext;
+                                len -= op;
+                                do {
+                                    *out++ = *from++;
+                                } while (--op);
+                                from = out - dist;      /* rest from output */
+                            }
+                        }
+                    }
+                    else {                      /* contiguous in window */
+                        from += wnext - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    while (len > 2) {
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        len -= 3;
+                    }
+                    if (len) {
+                        *out++ = *from++;
+                        if (len > 1)
+                            *out++ = *from++;
+                    }
+                }
+                else {
+                    from = out - dist;          /* copy direct from output */
+                    do {                        /* minimum length is three */
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        len -= 3;
+                    } while (len > 2);
+                    if (len) {
+                        *out++ = *from++;
+                        if (len > 1)
+                            *out++ = *from++;
+                    }
+                }
+            }
+            else if ((op & 64) == 0) {          /* 2nd level distance code */
+                here = dcode[here.val + (hold & ((1U << op) - 1))];
+                goto dodist;
+            }
+            else {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+        }
+        else if ((op & 64) == 0) {              /* 2nd level length code */
+            here = lcode[here.val + (hold & ((1U << op) - 1))];
+            goto dolen;
+        }
+        else if (op & 32) {                     /* end-of-block */
+            Tracevv((stderr, "inflate:         end of block\n"));
+            state->mode = TYPE;
+            break;
+        }
+        else {
+            strm->msg = (char *)"invalid literal/length code";
+            state->mode = BAD;
+            break;
+        }
+    } while (in < last && out < end);
+
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    len = bits >> 3;
+    in -= len;
+    bits -= len << 3;
+    hold &= (1U << bits) - 1;
+
+    /* update state and return */
+    strm->next_in = in;
+    strm->next_out = out;
+    strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
+    strm->avail_out = (unsigned)(out < end ?
+                                 257 + (end - out) : 257 - (out - end));
+    state->hold = hold;
+    state->bits = bits;
+    return;
+}
+
+/*
+   inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
+   - Using bit fields for code structure
+   - Different op definition to avoid & for extra bits (do & for table bits)
+   - Three separate decoding do-loops for direct, window, and wnext == 0
+   - Special case for distance > 1 copies to do overlapped load and store copy
+   - Explicit branch predictions (based on measured branch probabilities)
+   - Deferring match copy and interspersed it with decoding subsequent codes
+   - Swapping literal/length else
+   - Swapping window/direct else
+   - Larger unrolled copy loops (three is about right)
+   - Moving len -= 3 statement into middle of loop
+ */
+
+#endif /* !ASMINF */
diff --git a/xs/src/png/zlib/inffast.h b/xs/src/png/zlib/inffast.h
new file mode 100644
index 000000000..e5c1aa4ca
--- /dev/null
+++ b/xs/src/png/zlib/inffast.h
@@ -0,0 +1,11 @@
+/* inffast.h -- header to use inffast.c
+ * Copyright (C) 1995-2003, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+void ZLIB_INTERNAL inflate_fast OF((z_streamp strm, unsigned start));
diff --git a/xs/src/png/zlib/inffixed.h b/xs/src/png/zlib/inffixed.h
new file mode 100644
index 000000000..d62832776
--- /dev/null
+++ b/xs/src/png/zlib/inffixed.h
@@ -0,0 +1,94 @@
+    /* inffixed.h -- table for decoding fixed codes
+     * Generated automatically by makefixed().
+     */
+
+    /* WARNING: this file should *not* be used by applications.
+       It is part of the implementation of this library and is
+       subject to change. Applications should only use zlib.h.
+     */
+
+    static const code lenfix[512] = {
+        {96,7,0},{0,8,80},{0,8,16},{20,8,115},{18,7,31},{0,8,112},{0,8,48},
+        {0,9,192},{16,7,10},{0,8,96},{0,8,32},{0,9,160},{0,8,0},{0,8,128},
+        {0,8,64},{0,9,224},{16,7,6},{0,8,88},{0,8,24},{0,9,144},{19,7,59},
+        {0,8,120},{0,8,56},{0,9,208},{17,7,17},{0,8,104},{0,8,40},{0,9,176},
+        {0,8,8},{0,8,136},{0,8,72},{0,9,240},{16,7,4},{0,8,84},{0,8,20},
+        {21,8,227},{19,7,43},{0,8,116},{0,8,52},{0,9,200},{17,7,13},{0,8,100},
+        {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},{16,7,8},
+        {0,8,92},{0,8,28},{0,9,152},{20,7,83},{0,8,124},{0,8,60},{0,9,216},
+        {18,7,23},{0,8,108},{0,8,44},{0,9,184},{0,8,12},{0,8,140},{0,8,76},
+        {0,9,248},{16,7,3},{0,8,82},{0,8,18},{21,8,163},{19,7,35},{0,8,114},
+        {0,8,50},{0,9,196},{17,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},
+        {0,8,130},{0,8,66},{0,9,228},{16,7,7},{0,8,90},{0,8,26},{0,9,148},
+        {20,7,67},{0,8,122},{0,8,58},{0,9,212},{18,7,19},{0,8,106},{0,8,42},
+        {0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},{16,7,5},{0,8,86},
+        {0,8,22},{64,8,0},{19,7,51},{0,8,118},{0,8,54},{0,9,204},{17,7,15},
+        {0,8,102},{0,8,38},{0,9,172},{0,8,6},{0,8,134},{0,8,70},{0,9,236},
+        {16,7,9},{0,8,94},{0,8,30},{0,9,156},{20,7,99},{0,8,126},{0,8,62},
+        {0,9,220},{18,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
+        {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{21,8,131},{18,7,31},
+        {0,8,113},{0,8,49},{0,9,194},{16,7,10},{0,8,97},{0,8,33},{0,9,162},
+        {0,8,1},{0,8,129},{0,8,65},{0,9,226},{16,7,6},{0,8,89},{0,8,25},
+        {0,9,146},{19,7,59},{0,8,121},{0,8,57},{0,9,210},{17,7,17},{0,8,105},
+        {0,8,41},{0,9,178},{0,8,9},{0,8,137},{0,8,73},{0,9,242},{16,7,4},
+        {0,8,85},{0,8,21},{16,8,258},{19,7,43},{0,8,117},{0,8,53},{0,9,202},
+        {17,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},{0,8,69},
+        {0,9,234},{16,7,8},{0,8,93},{0,8,29},{0,9,154},{20,7,83},{0,8,125},
+        {0,8,61},{0,9,218},{18,7,23},{0,8,109},{0,8,45},{0,9,186},{0,8,13},
+        {0,8,141},{0,8,77},{0,9,250},{16,7,3},{0,8,83},{0,8,19},{21,8,195},
+        {19,7,35},{0,8,115},{0,8,51},{0,9,198},{17,7,11},{0,8,99},{0,8,35},
+        {0,9,166},{0,8,3},{0,8,131},{0,8,67},{0,9,230},{16,7,7},{0,8,91},
+        {0,8,27},{0,9,150},{20,7,67},{0,8,123},{0,8,59},{0,9,214},{18,7,19},
+        {0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},{0,8,75},{0,9,246},
+        {16,7,5},{0,8,87},{0,8,23},{64,8,0},{19,7,51},{0,8,119},{0,8,55},
+        {0,9,206},{17,7,15},{0,8,103},{0,8,39},{0,9,174},{0,8,7},{0,8,135},
+        {0,8,71},{0,9,238},{16,7,9},{0,8,95},{0,8,31},{0,9,158},{20,7,99},
+        {0,8,127},{0,8,63},{0,9,222},{18,7,27},{0,8,111},{0,8,47},{0,9,190},
+        {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},{0,8,16},
+        {20,8,115},{18,7,31},{0,8,112},{0,8,48},{0,9,193},{16,7,10},{0,8,96},
+        {0,8,32},{0,9,161},{0,8,0},{0,8,128},{0,8,64},{0,9,225},{16,7,6},
+        {0,8,88},{0,8,24},{0,9,145},{19,7,59},{0,8,120},{0,8,56},{0,9,209},
+        {17,7,17},{0,8,104},{0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},
+        {0,9,241},{16,7,4},{0,8,84},{0,8,20},{21,8,227},{19,7,43},{0,8,116},
+        {0,8,52},{0,9,201},{17,7,13},{0,8,100},{0,8,36},{0,9,169},{0,8,4},
+        {0,8,132},{0,8,68},{0,9,233},{16,7,8},{0,8,92},{0,8,28},{0,9,153},
+        {20,7,83},{0,8,124},{0,8,60},{0,9,217},{18,7,23},{0,8,108},{0,8,44},
+        {0,9,185},{0,8,12},{0,8,140},{0,8,76},{0,9,249},{16,7,3},{0,8,82},
+        {0,8,18},{21,8,163},{19,7,35},{0,8,114},{0,8,50},{0,9,197},{17,7,11},
+        {0,8,98},{0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
+        {16,7,7},{0,8,90},{0,8,26},{0,9,149},{20,7,67},{0,8,122},{0,8,58},
+        {0,9,213},{18,7,19},{0,8,106},{0,8,42},{0,9,181},{0,8,10},{0,8,138},
+        {0,8,74},{0,9,245},{16,7,5},{0,8,86},{0,8,22},{64,8,0},{19,7,51},
+        {0,8,118},{0,8,54},{0,9,205},{17,7,15},{0,8,102},{0,8,38},{0,9,173},
+        {0,8,6},{0,8,134},{0,8,70},{0,9,237},{16,7,9},{0,8,94},{0,8,30},
+        {0,9,157},{20,7,99},{0,8,126},{0,8,62},{0,9,221},{18,7,27},{0,8,110},
+        {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},{96,7,0},
+        {0,8,81},{0,8,17},{21,8,131},{18,7,31},{0,8,113},{0,8,49},{0,9,195},
+        {16,7,10},{0,8,97},{0,8,33},{0,9,163},{0,8,1},{0,8,129},{0,8,65},
+        {0,9,227},{16,7,6},{0,8,89},{0,8,25},{0,9,147},{19,7,59},{0,8,121},
+        {0,8,57},{0,9,211},{17,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},
+        {0,8,137},{0,8,73},{0,9,243},{16,7,4},{0,8,85},{0,8,21},{16,8,258},
+        {19,7,43},{0,8,117},{0,8,53},{0,9,203},{17,7,13},{0,8,101},{0,8,37},
+        {0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},{16,7,8},{0,8,93},
+        {0,8,29},{0,9,155},{20,7,83},{0,8,125},{0,8,61},{0,9,219},{18,7,23},
+        {0,8,109},{0,8,45},{0,9,187},{0,8,13},{0,8,141},{0,8,77},{0,9,251},
+        {16,7,3},{0,8,83},{0,8,19},{21,8,195},{19,7,35},{0,8,115},{0,8,51},
+        {0,9,199},{17,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
+        {0,8,67},{0,9,231},{16,7,7},{0,8,91},{0,8,27},{0,9,151},{20,7,67},
+        {0,8,123},{0,8,59},{0,9,215},{18,7,19},{0,8,107},{0,8,43},{0,9,183},
+        {0,8,11},{0,8,139},{0,8,75},{0,9,247},{16,7,5},{0,8,87},{0,8,23},
+        {64,8,0},{19,7,51},{0,8,119},{0,8,55},{0,9,207},{17,7,15},{0,8,103},
+        {0,8,39},{0,9,175},{0,8,7},{0,8,135},{0,8,71},{0,9,239},{16,7,9},
+        {0,8,95},{0,8,31},{0,9,159},{20,7,99},{0,8,127},{0,8,63},{0,9,223},
+        {18,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},{0,8,79},
+        {0,9,255}
+    };
+
+    static const code distfix[32] = {
+        {16,5,1},{23,5,257},{19,5,17},{27,5,4097},{17,5,5},{25,5,1025},
+        {21,5,65},{29,5,16385},{16,5,3},{24,5,513},{20,5,33},{28,5,8193},
+        {18,5,9},{26,5,2049},{22,5,129},{64,5,0},{16,5,2},{23,5,385},
+        {19,5,25},{27,5,6145},{17,5,7},{25,5,1537},{21,5,97},{29,5,24577},
+        {16,5,4},{24,5,769},{20,5,49},{28,5,12289},{18,5,13},{26,5,3073},
+        {22,5,193},{64,5,0}
+    };
diff --git a/xs/src/png/zlib/inflate.c b/xs/src/png/zlib/inflate.c
new file mode 100644
index 000000000..ac333e8c2
--- /dev/null
+++ b/xs/src/png/zlib/inflate.c
@@ -0,0 +1,1561 @@
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * Change history:
+ *
+ * 1.2.beta0    24 Nov 2002
+ * - First version -- complete rewrite of inflate to simplify code, avoid
+ *   creation of window when not needed, minimize use of window when it is
+ *   needed, make inffast.c even faster, implement gzip decoding, and to
+ *   improve code readability and style over the previous zlib inflate code
+ *
+ * 1.2.beta1    25 Nov 2002
+ * - Use pointers for available input and output checking in inffast.c
+ * - Remove input and output counters in inffast.c
+ * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
+ * - Remove unnecessary second byte pull from length extra in inffast.c
+ * - Unroll direct copy to three copies per loop in inffast.c
+ *
+ * 1.2.beta2    4 Dec 2002
+ * - Change external routine names to reduce potential conflicts
+ * - Correct filename to inffixed.h for fixed tables in inflate.c
+ * - Make hbuf[] unsigned char to match parameter type in inflate.c
+ * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
+ *   to avoid negation problem on Alphas (64 bit) in inflate.c
+ *
+ * 1.2.beta3    22 Dec 2002
+ * - Add comments on state->bits assertion in inffast.c
+ * - Add comments on op field in inftrees.h
+ * - Fix bug in reuse of allocated window after inflateReset()
+ * - Remove bit fields--back to byte structure for speed
+ * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
+ * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
+ * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
+ * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
+ * - Use local copies of stream next and avail values, as well as local bit
+ *   buffer and bit count in inflate()--for speed when inflate_fast() not used
+ *
+ * 1.2.beta4    1 Jan 2003
+ * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
+ * - Move a comment on output buffer sizes from inffast.c to inflate.c
+ * - Add comments in inffast.c to introduce the inflate_fast() routine
+ * - Rearrange window copies in inflate_fast() for speed and simplification
+ * - Unroll last copy for window match in inflate_fast()
+ * - Use local copies of window variables in inflate_fast() for speed
+ * - Pull out common wnext == 0 case for speed in inflate_fast()
+ * - Make op and len in inflate_fast() unsigned for consistency
+ * - Add FAR to lcode and dcode declarations in inflate_fast()
+ * - Simplified bad distance check in inflate_fast()
+ * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
+ *   source file infback.c to provide a call-back interface to inflate for
+ *   programs like gzip and unzip -- uses window as output buffer to avoid
+ *   window copying
+ *
+ * 1.2.beta5    1 Jan 2003
+ * - Improved inflateBack() interface to allow the caller to provide initial
+ *   input in strm.
+ * - Fixed stored blocks bug in inflateBack()
+ *
+ * 1.2.beta6    4 Jan 2003
+ * - Added comments in inffast.c on effectiveness of POSTINC
+ * - Typecasting all around to reduce compiler warnings
+ * - Changed loops from while (1) or do {} while (1) to for (;;), again to
+ *   make compilers happy
+ * - Changed type of window in inflateBackInit() to unsigned char *
+ *
+ * 1.2.beta7    27 Jan 2003
+ * - Changed many types to unsigned or unsigned short to avoid warnings
+ * - Added inflateCopy() function
+ *
+ * 1.2.0        9 Mar 2003
+ * - Changed inflateBack() interface to provide separate opaque descriptors
+ *   for the in() and out() functions
+ * - Changed inflateBack() argument and in_func typedef to swap the length
+ *   and buffer address return values for the input function
+ * - Check next_in and next_out for Z_NULL on entry to inflate()
+ *
+ * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef MAKEFIXED
+#  ifndef BUILDFIXED
+#    define BUILDFIXED
+#  endif
+#endif
+
+/* function prototypes */
+local int inflateStateCheck OF((z_streamp strm));
+local void fixedtables OF((struct inflate_state FAR *state));
+local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
+                           unsigned copy));
+#ifdef BUILDFIXED
+   void makefixed OF((void));
+#endif
+local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
+                              unsigned len));
+
+local int inflateStateCheck(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state == Z_NULL || state->strm != strm ||
+        state->mode < HEAD || state->mode > SYNC)
+        return 1;
+    return 0;
+}
+
+int ZEXPORT inflateResetKeep(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    strm->total_in = strm->total_out = state->total = 0;
+    strm->msg = Z_NULL;
+    if (state->wrap)        /* to support ill-conceived Java test suite */
+        strm->adler = state->wrap & 1;
+    state->mode = HEAD;
+    state->last = 0;
+    state->havedict = 0;
+    state->dmax = 32768U;
+    state->head = Z_NULL;
+    state->hold = 0;
+    state->bits = 0;
+    state->lencode = state->distcode = state->next = state->codes;
+    state->sane = 1;
+    state->back = -1;
+    Tracev((stderr, "inflate: reset\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    state->wsize = 0;
+    state->whave = 0;
+    state->wnext = 0;
+    return inflateResetKeep(strm);
+}
+
+int ZEXPORT inflateReset2(strm, windowBits)
+z_streamp strm;
+int windowBits;
+{
+    int wrap;
+    struct inflate_state FAR *state;
+
+    /* get the state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* extract wrap request from windowBits parameter */
+    if (windowBits < 0) {
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        wrap = (windowBits >> 4) + 5;
+#ifdef GUNZIP
+        if (windowBits < 48)
+            windowBits &= 15;
+#endif
+    }
+
+    /* set number of window bits, free window if different */
+    if (windowBits && (windowBits < 8 || windowBits > 15))
+        return Z_STREAM_ERROR;
+    if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
+        ZFREE(strm, state->window);
+        state->window = Z_NULL;
+    }
+
+    /* update state and reset the rest of it */
+    state->wrap = wrap;
+    state->wbits = (unsigned)windowBits;
+    return inflateReset(strm);
+}
+
+int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
+z_streamp strm;
+int windowBits;
+const char *version;
+int stream_size;
+{
+    int ret;
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zfree = zcfree;
+#endif
+    state = (struct inflate_state FAR *)
+            ZALLOC(strm, 1, sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (struct internal_state FAR *)state;
+    state->strm = strm;
+    state->window = Z_NULL;
+    state->mode = HEAD;     /* to pass state test in inflateReset2() */
+    ret = inflateReset2(strm, windowBits);
+    if (ret != Z_OK) {
+        ZFREE(strm, state);
+        strm->state = Z_NULL;
+    }
+    return ret;
+}
+
+int ZEXPORT inflateInit_(strm, version, stream_size)
+z_streamp strm;
+const char *version;
+int stream_size;
+{
+    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+}
+
+int ZEXPORT inflatePrime(strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (bits < 0) {
+        state->hold = 0;
+        state->bits = 0;
+        return Z_OK;
+    }
+    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state->hold += (unsigned)value << state->bits;
+    state->bits += (uInt)bits;
+    return Z_OK;
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state->lens[sym++] = 8;
+        while (sym < 256) state->lens[sym++] = 9;
+        while (sym < 280) state->lens[sym++] = 7;
+        while (sym < 288) state->lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state->lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
+}
+
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+/*
+   Write out the inffixed.h that is #include'd above.  Defining MAKEFIXED also
+   defines BUILDFIXED, so the tables are built on the fly.  makefixed() writes
+   those tables to stdout, which would be piped to inffixed.h.  A small program
+   can simply call makefixed to do this:
+
+    void makefixed(void);
+
+    int main(void)
+    {
+        makefixed();
+        return 0;
+    }
+
+   Then that can be linked with zlib built with MAKEFIXED defined and run:
+
+    a.out > inffixed.h
+ */
+void makefixed()
+{
+    unsigned low, size;
+    struct inflate_state state;
+
+    fixedtables(&state);
+    puts("    /* inffixed.h -- table for decoding fixed codes");
+    puts("     * Generated automatically by makefixed().");
+    puts("     */");
+    puts("");
+    puts("    /* WARNING: this file should *not* be used by applications.");
+    puts("       It is part of the implementation of this library and is");
+    puts("       subject to change. Applications should only use zlib.h.");
+    puts("     */");
+    puts("");
+    size = 1U << 9;
+    printf("    static const code lenfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 7) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
+               state.lencode[low].bits, state.lencode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+    size = 1U << 5;
+    printf("\n    static const code distfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 6) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
+               state.distcode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+}
+#endif /* MAKEFIXED */
+
+/*
+   Update the window with the last wsize (normally 32K) bytes written before
+   returning.  If window does not exist yet, create it.  This is only called
+   when a window is already in use, or when output has been written during this
+   inflate call, but the end of the deflate stream has not been reached yet.
+   It is also called to create a window for dictionary data when a dictionary
+   is loaded.
+
+   Providing output buffers larger than 32K to inflate() should provide a speed
+   advantage, since only the last 32K of output is copied to the sliding window
+   upon return from inflate(), and since all distances after the first 32K of
+   output will fall in the output data, making match copies simpler and faster.
+   The advantage may be dependent on the size of the processor's data caches.
+ */
+local int updatewindow(strm, end, copy)
+z_streamp strm;
+const Bytef *end;
+unsigned copy;
+{
+    struct inflate_state FAR *state;
+    unsigned dist;
+
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* if it hasn't been done already, allocate space for the window */
+    if (state->window == Z_NULL) {
+        state->window = (unsigned char FAR *)
+                        ZALLOC(strm, 1U << state->wbits,
+                               sizeof(unsigned char));
+        if (state->window == Z_NULL) return 1;
+    }
+
+    /* if window not in use yet, initialize */
+    if (state->wsize == 0) {
+        state->wsize = 1U << state->wbits;
+        state->wnext = 0;
+        state->whave = 0;
+    }
+
+    /* copy state->wsize or less output bytes into the circular window */
+    if (copy >= state->wsize) {
+        zmemcpy(state->window, end - state->wsize, state->wsize);
+        state->wnext = 0;
+        state->whave = state->wsize;
+    }
+    else {
+        dist = state->wsize - state->wnext;
+        if (dist > copy) dist = copy;
+        zmemcpy(state->window + state->wnext, end - copy, dist);
+        copy -= dist;
+        if (copy) {
+            zmemcpy(state->window, end - copy, copy);
+            state->wnext = copy;
+            state->whave = state->wsize;
+        }
+        else {
+            state->wnext += dist;
+            if (state->wnext == state->wsize) state->wnext = 0;
+            if (state->whave < state->wsize) state->whave += dist;
+        }
+    }
+    return 0;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#ifdef GUNZIP
+#  define UPDATE(check, buf, len) \
+    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
+#else
+#  define UPDATE(check, buf, len) adler32(check, buf, len)
+#endif
+
+/* check macros for header crc */
+#ifdef GUNZIP
+#  define CRC2(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        check = crc32(check, hbuf, 2); \
+    } while (0)
+
+#  define CRC4(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        hbuf[2] = (unsigned char)((word) >> 16); \
+        hbuf[3] = (unsigned char)((word) >> 24); \
+        check = crc32(check, hbuf, 4); \
+    } while (0)
+#endif
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+   if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        if (have == 0) goto inf_leave; \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/*
+   inflate() uses a state machine to process as much input data and generate as
+   much output data as possible before returning.  The state machine is
+   structured roughly as follows:
+
+    for (;;) switch (state) {
+    ...
+    case STATEn:
+        if (not enough input data or output space to make progress)
+            return;
+        ... make progress ...
+        state = STATEm;
+        break;
+    ...
+    }
+
+   so when inflate() is called again, the same case is attempted again, and
+   if the appropriate resources are provided, the machine proceeds to the
+   next state.  The NEEDBITS() macro is usually the way the state evaluates
+   whether it can proceed or should return.  NEEDBITS() does the return if
+   the requested bits are not available.  The typical use of the BITS macros
+   is:
+
+        NEEDBITS(n);
+        ... do something with BITS(n) ...
+        DROPBITS(n);
+
+   where NEEDBITS(n) either returns from inflate() if there isn't enough
+   input left to load n bits into the accumulator, or it continues.  BITS(n)
+   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
+   the low n bits off the accumulator.  INITBITS() clears the accumulator
+   and sets the number of available bits to zero.  BYTEBITS() discards just
+   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
+   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+   if there is no input available.  The decoding of variable length codes uses
+   PULLBYTE() directly in order to pull just enough bytes to decode the next
+   code, and no more.
+
+   Some states loop until they get enough input, making sure that enough
+   state information is maintained to continue the loop where it left off
+   if NEEDBITS() returns in the loop.  For example, want, need, and keep
+   would all have to actually be part of the saved state in case NEEDBITS()
+   returns:
+
+    case STATEw:
+        while (want < need) {
+            NEEDBITS(n);
+            keep[want++] = BITS(n);
+            DROPBITS(n);
+        }
+        state = STATEx;
+    case STATEx:
+
+   As shown above, if the next state is also the next case, then the break
+   is omitted.
+
+   A state may also return if there is not enough output space available to
+   complete that state.  Those states are copying stored data, writing a
+   literal byte, and copying a matching string.
+
+   When returning, a "goto inf_leave" is used to update the total counters,
+   update the check value, and determine whether any progress has been made
+   during that inflate() call in order to return the proper return code.
+   Progress is defined as a change in either strm->avail_in or strm->avail_out.
+   When there is a window, goto inf_leave will update the window with the last
+   output written.  If a goto inf_leave occurs in the middle of decompression
+   and there is no window currently, goto inf_leave will create one and copy
+   output to the window for the next call of inflate().
+
+   In this implementation, the flush parameter of inflate() only affects the
+   return code (per zlib.h).  inflate() always writes as much as possible to
+   strm->next_out, given the space available and the provided input--the effect
+   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
+   the allocation of and copying into a sliding window until necessary, which
+   provides the effect documented in zlib.h for Z_FINISH when the entire input
+   stream available.  So the only thing the flush parameter actually does is:
+   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
+   will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int ZEXPORT inflate(strm, flush)
+z_streamp strm;
+int flush;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned in, out;           /* save starting available input and output */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+#ifdef GUNZIP
+    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
+#endif
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
+        (strm->next_in == Z_NULL && strm->avail_in != 0))
+        return Z_STREAM_ERROR;
+
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
+    LOAD();
+    in = have;
+    out = left;
+    ret = Z_OK;
+    for (;;)
+        switch (state->mode) {
+        case HEAD:
+            if (state->wrap == 0) {
+                state->mode = TYPEDO;
+                break;
+            }
+            NEEDBITS(16);
+#ifdef GUNZIP
+            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                if (state->wbits == 0)
+                    state->wbits = 15;
+                state->check = crc32(0L, Z_NULL, 0);
+                CRC2(state->check, hold);
+                INITBITS();
+                state->mode = FLAGS;
+                break;
+            }
+            state->flags = 0;           /* expect zlib header */
+            if (state->head != Z_NULL)
+                state->head->done = -1;
+            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
+#else
+            if (
+#endif
+                ((BITS(8) << 8) + (hold >> 8)) % 31) {
+                strm->msg = (char *)"incorrect header check";
+                state->mode = BAD;
+                break;
+            }
+            if (BITS(4) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            DROPBITS(4);
+            len = BITS(4) + 8;
+            if (state->wbits == 0)
+                state->wbits = len;
+            if (len > 15 || len > state->wbits) {
+                strm->msg = (char *)"invalid window size";
+                state->mode = BAD;
+                break;
+            }
+            state->dmax = 1U << len;
+            Tracev((stderr, "inflate:   zlib header ok\n"));
+            strm->adler = state->check = adler32(0L, Z_NULL, 0);
+            state->mode = hold & 0x200 ? DICTID : TYPE;
+            INITBITS();
+            break;
+#ifdef GUNZIP
+        case FLAGS:
+            NEEDBITS(16);
+            state->flags = (int)(hold);
+            if ((state->flags & 0xff) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            if (state->flags & 0xe000) {
+                strm->msg = (char *)"unknown header flags set";
+                state->mode = BAD;
+                break;
+            }
+            if (state->head != Z_NULL)
+                state->head->text = (int)((hold >> 8) & 1);
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
+            INITBITS();
+            state->mode = TIME;
+        case TIME:
+            NEEDBITS(32);
+            if (state->head != Z_NULL)
+                state->head->time = hold;
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC4(state->check, hold);
+            INITBITS();
+            state->mode = OS;
+        case OS:
+            NEEDBITS(16);
+            if (state->head != Z_NULL) {
+                state->head->xflags = (int)(hold & 0xff);
+                state->head->os = (int)(hold >> 8);
+            }
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
+            INITBITS();
+            state->mode = EXLEN;
+        case EXLEN:
+            if (state->flags & 0x0400) {
+                NEEDBITS(16);
+                state->length = (unsigned)(hold);
+                if (state->head != Z_NULL)
+                    state->head->extra_len = (unsigned)hold;
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    CRC2(state->check, hold);
+                INITBITS();
+            }
+            else if (state->head != Z_NULL)
+                state->head->extra = Z_NULL;
+            state->mode = EXTRA;
+        case EXTRA:
+            if (state->flags & 0x0400) {
+                copy = state->length;
+                if (copy > have) copy = have;
+                if (copy) {
+                    if (state->head != Z_NULL &&
+                        state->head->extra != Z_NULL) {
+                        len = state->head->extra_len - state->length;
+                        zmemcpy(state->head->extra + len, next,
+                                len + copy > state->head->extra_max ?
+                                state->head->extra_max - len : copy);
+                    }
+                    if ((state->flags & 0x0200) && (state->wrap & 4))
+                        state->check = crc32(state->check, next, copy);
+                    have -= copy;
+                    next += copy;
+                    state->length -= copy;
+                }
+                if (state->length) goto inf_leave;
+            }
+            state->length = 0;
+            state->mode = NAME;
+        case NAME:
+            if (state->flags & 0x0800) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state->head != Z_NULL &&
+                            state->head->name != Z_NULL &&
+                            state->length < state->head->name_max)
+                        state->head->name[state->length++] = (Bytef)len;
+                } while (len && copy < have);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    state->check = crc32(state->check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state->head != Z_NULL)
+                state->head->name = Z_NULL;
+            state->length = 0;
+            state->mode = COMMENT;
+        case COMMENT:
+            if (state->flags & 0x1000) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state->head != Z_NULL &&
+                            state->head->comment != Z_NULL &&
+                            state->length < state->head->comm_max)
+                        state->head->comment[state->length++] = (Bytef)len;
+                } while (len && copy < have);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    state->check = crc32(state->check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state->head != Z_NULL)
+                state->head->comment = Z_NULL;
+            state->mode = HCRC;
+        case HCRC:
+            if (state->flags & 0x0200) {
+                NEEDBITS(16);
+                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
+                    strm->msg = (char *)"header crc mismatch";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+            }
+            if (state->head != Z_NULL) {
+                state->head->hcrc = (int)((state->flags >> 9) & 1);
+                state->head->done = 1;
+            }
+            strm->adler = state->check = crc32(0L, Z_NULL, 0);
+            state->mode = TYPE;
+            break;
+#endif
+        case DICTID:
+            NEEDBITS(32);
+            strm->adler = state->check = ZSWAP32(hold);
+            INITBITS();
+            state->mode = DICT;
+        case DICT:
+            if (state->havedict == 0) {
+                RESTORE();
+                return Z_NEED_DICT;
+            }
+            strm->adler = state->check = adler32(0L, Z_NULL, 0);
+            state->mode = TYPE;
+        case TYPE:
+            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
+        case TYPEDO:
+            if (state->last) {
+                BYTEBITS();
+                state->mode = CHECK;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables(state);
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = LEN_;             /* decode codes */
+                if (flush == Z_TREES) {
+                    DROPBITS(2);
+                    goto inf_leave;
+                }
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+        case STORED:
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %u\n",
+                    state->length));
+            INITBITS();
+            state->mode = COPY_;
+            if (flush == Z_TREES) goto inf_leave;
+        case COPY_:
+            state->mode = COPY;
+        case COPY:
+            copy = state->length;
+            if (copy) {
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                if (copy == 0) goto inf_leave;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+                break;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            state->mode = TYPE;
+            break;
+        case TABLE:
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+            state->have = 0;
+            state->mode = LENLENS;
+        case LENLENS:
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (const code FAR *)(state->next);
+            state->lenbits = 7;
+            ret = inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+            state->have = 0;
+            state->mode = CODELENS;
+        case CODELENS:
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = state->lens[state->have - 1];
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                state->mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftrees.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            state->lencode = (const code FAR *)(state->next);
+            state->lenbits = 9;
+            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (const code FAR *)(state->next);
+            state->distbits = 6;
+            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN_;
+            if (flush == Z_TREES) goto inf_leave;
+        case LEN_:
+            state->mode = LEN;
+        case LEN:
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                inflate_fast(strm, out);
+                LOAD();
+                if (state->mode == TYPE)
+                    state->back = -1;
+                break;
+            }
+            state->back = 0;
+            for (;;) {
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+                state->back += last.bits;
+            }
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            state->length = (unsigned)here.val;
+            if ((int)(here.op) == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                state->mode = LIT;
+                break;
+            }
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                state->back = -1;
+                state->mode = TYPE;
+                break;
+            }
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+            state->extra = (unsigned)(here.op) & 15;
+            state->mode = LENEXT;
+        case LENEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+                state->back += state->extra;
+            }
+            Tracevv((stderr, "inflate:         length %u\n", state->length));
+            state->was = state->length;
+            state->mode = DIST;
+        case DIST:
+            for (;;) {
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+                state->back += last.bits;
+            }
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)here.val;
+            state->extra = (unsigned)(here.op) & 15;
+            state->mode = DISTEXT;
+        case DISTEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+                state->back += state->extra;
+            }
+#ifdef INFLATE_STRICT
+            if (state->offset > state->dmax) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
+            state->mode = MATCH;
+        case MATCH:
+            if (left == 0) goto inf_leave;
+            copy = out - left;
+            if (state->offset > copy) {         /* copy from window */
+                copy = state->offset - copy;
+                if (copy > state->whave) {
+                    if (state->sane) {
+                        strm->msg = (char *)"invalid distance too far back";
+                        state->mode = BAD;
+                        break;
+                    }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                    Trace((stderr, "inflate.c too far\n"));
+                    copy -= state->whave;
+                    if (copy > state->length) copy = state->length;
+                    if (copy > left) copy = left;
+                    left -= copy;
+                    state->length -= copy;
+                    do {
+                        *put++ = 0;
+                    } while (--copy);
+                    if (state->length == 0) state->mode = LEN;
+                    break;
+#endif
+                }
+                if (copy > state->wnext) {
+                    copy -= state->wnext;
+                    from = state->window + (state->wsize - copy);
+                }
+                else
+                    from = state->window + (state->wnext - copy);
+                if (copy > state->length) copy = state->length;
+            }
+            else {                              /* copy from output */
+                from = put - state->offset;
+                copy = state->length;
+            }
+            if (copy > left) copy = left;
+            left -= copy;
+            state->length -= copy;
+            do {
+                *put++ = *from++;
+            } while (--copy);
+            if (state->length == 0) state->mode = LEN;
+            break;
+        case LIT:
+            if (left == 0) goto inf_leave;
+            *put++ = (unsigned char)(state->length);
+            left--;
+            state->mode = LEN;
+            break;
+        case CHECK:
+            if (state->wrap) {
+                NEEDBITS(32);
+                out -= left;
+                strm->total_out += out;
+                state->total += out;
+                if ((state->wrap & 4) && out)
+                    strm->adler = state->check =
+                        UPDATE(state->check, put - out, out);
+                out = left;
+                if ((state->wrap & 4) && (
+#ifdef GUNZIP
+                     state->flags ? hold :
+#endif
+                     ZSWAP32(hold)) != state->check) {
+                    strm->msg = (char *)"incorrect data check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   check matches trailer\n"));
+            }
+#ifdef GUNZIP
+            state->mode = LENGTH;
+        case LENGTH:
+            if (state->wrap && state->flags) {
+                NEEDBITS(32);
+                if (hold != (state->total & 0xffffffffUL)) {
+                    strm->msg = (char *)"incorrect length check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   length matches trailer\n"));
+            }
+#endif
+            state->mode = DONE;
+        case DONE:
+            ret = Z_STREAM_END;
+            goto inf_leave;
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+        case MEM:
+            return Z_MEM_ERROR;
+        case SYNC:
+        default:
+            return Z_STREAM_ERROR;
+        }
+
+    /*
+       Return from inflate(), updating the total counts and the check value.
+       If there was no progress during the inflate() call, return a buffer
+       error.  Call updatewindow() to create and/or update the window state.
+       Note: a memory error from inflate() is non-recoverable.
+     */
+  inf_leave:
+    RESTORE();
+    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
+            (state->mode < CHECK || flush != Z_FINISH)))
+        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
+            state->mode = MEM;
+            return Z_MEM_ERROR;
+        }
+    in -= strm->avail_in;
+    out -= strm->avail_out;
+    strm->total_in += in;
+    strm->total_out += out;
+    state->total += out;
+    if ((state->wrap & 4) && out)
+        strm->adler = state->check =
+            UPDATE(state->check, strm->next_out - out, out);
+    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
+                      (state->mode == TYPE ? 128 : 0) +
+                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
+    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+        ret = Z_BUF_ERROR;
+    return ret;
+}
+
+int ZEXPORT inflateEnd(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->window != Z_NULL) ZFREE(strm, state->window);
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+Bytef *dictionary;
+uInt *dictLength;
+{
+    struct inflate_state FAR *state;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* copy dictionary */
+    if (state->whave && dictionary != Z_NULL) {
+        zmemcpy(dictionary, state->window + state->wnext,
+                state->whave - state->wnext);
+        zmemcpy(dictionary + state->whave - state->wnext,
+                state->window, state->wnext);
+    }
+    if (dictLength != Z_NULL)
+        *dictLength = state->whave;
+    return Z_OK;
+}
+
+int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+const Bytef *dictionary;
+uInt dictLength;
+{
+    struct inflate_state FAR *state;
+    unsigned long dictid;
+    int ret;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->wrap != 0 && state->mode != DICT)
+        return Z_STREAM_ERROR;
+
+    /* check for correct dictionary identifier */
+    if (state->mode == DICT) {
+        dictid = adler32(0L, Z_NULL, 0);
+        dictid = adler32(dictid, dictionary, dictLength);
+        if (dictid != state->check)
+            return Z_DATA_ERROR;
+    }
+
+    /* copy dictionary to window using updatewindow(), which will amend the
+       existing dictionary if appropriate */
+    ret = updatewindow(strm, dictionary + dictLength, dictLength);
+    if (ret) {
+        state->mode = MEM;
+        return Z_MEM_ERROR;
+    }
+    state->havedict = 1;
+    Tracev((stderr, "inflate:   dictionary set\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetHeader(strm, head)
+z_streamp strm;
+gz_headerp head;
+{
+    struct inflate_state FAR *state;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
+
+    /* save header structure */
+    state->head = head;
+    head->done = 0;
+    return Z_OK;
+}
+
+/*
+   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
+   or when out of input.  When called, *have is the number of pattern bytes
+   found in order so far, in 0..3.  On return *have is updated to the new
+   state.  If on return *have equals four, then the pattern was found and the
+   return value is how many bytes were read including the last byte of the
+   pattern.  If *have is less than four, then the pattern has not been found
+   yet and the return value is len.  In the latter case, syncsearch() can be
+   called again with more data and the *have state.  *have is initialized to
+   zero for the first call.
+ */
+local unsigned syncsearch(have, buf, len)
+unsigned FAR *have;
+const unsigned char FAR *buf;
+unsigned len;
+{
+    unsigned got;
+    unsigned next;
+
+    got = *have;
+    next = 0;
+    while (next < len && got < 4) {
+        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+            got++;
+        else if (buf[next])
+            got = 0;
+        else
+            got = 4 - got;
+        next++;
+    }
+    *have = got;
+    return next;
+}
+
+int ZEXPORT inflateSync(strm)
+z_streamp strm;
+{
+    unsigned len;               /* number of bytes to look at or looked at */
+    unsigned long in, out;      /* temporary to save total_in and total_out */
+    unsigned char buf[4];       /* to restore bit buffer to byte string */
+    struct inflate_state FAR *state;
+
+    /* check parameters */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+    /* if first time, start search in bit buffer */
+    if (state->mode != SYNC) {
+        state->mode = SYNC;
+        state->hold <<= state->bits & 7;
+        state->bits -= state->bits & 7;
+        len = 0;
+        while (state->bits >= 8) {
+            buf[len++] = (unsigned char)(state->hold);
+            state->hold >>= 8;
+            state->bits -= 8;
+        }
+        state->have = 0;
+        syncsearch(&(state->have), buf, len);
+    }
+
+    /* search available input */
+    len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
+    strm->avail_in -= len;
+    strm->next_in += len;
+    strm->total_in += len;
+
+    /* return no joy or set up to restart inflate() on a new block */
+    if (state->have != 4) return Z_DATA_ERROR;
+    in = strm->total_in;  out = strm->total_out;
+    inflateReset(strm);
+    strm->total_in = in;  strm->total_out = out;
+    state->mode = TYPE;
+    return Z_OK;
+}
+
+/*
+   Returns true if inflate is currently at the end of a block generated by
+   Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+   implementation to provide an additional safety check. PPP uses
+   Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+   block. When decompressing, PPP checks that at the end of input packet,
+   inflate is waiting for these length bytes.
+ */
+int ZEXPORT inflateSyncPoint(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    return state->mode == STORED && state->bits == 0;
+}
+
+int ZEXPORT inflateCopy(dest, source)
+z_streamp dest;
+z_streamp source;
+{
+    struct inflate_state FAR *state;
+    struct inflate_state FAR *copy;
+    unsigned char FAR *window;
+    unsigned wsize;
+
+    /* check input */
+    if (inflateStateCheck(source) || dest == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)source->state;
+
+    /* allocate space */
+    copy = (struct inflate_state FAR *)
+           ZALLOC(source, 1, sizeof(struct inflate_state));
+    if (copy == Z_NULL) return Z_MEM_ERROR;
+    window = Z_NULL;
+    if (state->window != Z_NULL) {
+        window = (unsigned char FAR *)
+                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
+        if (window == Z_NULL) {
+            ZFREE(source, copy);
+            return Z_MEM_ERROR;
+        }
+    }
+
+    /* copy state */
+    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+    zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
+    copy->strm = dest;
+    if (state->lencode >= state->codes &&
+        state->lencode <= state->codes + ENOUGH - 1) {
+        copy->lencode = copy->codes + (state->lencode - state->codes);
+        copy->distcode = copy->codes + (state->distcode - state->codes);
+    }
+    copy->next = copy->codes + (state->next - state->codes);
+    if (window != Z_NULL) {
+        wsize = 1U << state->wbits;
+        zmemcpy(window, state->window, wsize);
+    }
+    copy->window = window;
+    dest->state = (struct internal_state FAR *)copy;
+    return Z_OK;
+}
+
+int ZEXPORT inflateUndermine(strm, subvert)
+z_streamp strm;
+int subvert;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+    state->sane = !subvert;
+    return Z_OK;
+#else
+    (void)subvert;
+    state->sane = 1;
+    return Z_DATA_ERROR;
+#endif
+}
+
+int ZEXPORT inflateValidate(strm, check)
+z_streamp strm;
+int check;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (check)
+        state->wrap |= 4;
+    else
+        state->wrap &= ~4;
+    return Z_OK;
+}
+
+long ZEXPORT inflateMark(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm))
+        return -(1L << 16);
+    state = (struct inflate_state FAR *)strm->state;
+    return (long)(((unsigned long)((long)state->back)) << 16) +
+        (state->mode == COPY ? state->length :
+            (state->mode == MATCH ? state->was - state->length : 0));
+}
+
+unsigned long ZEXPORT inflateCodesUsed(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm)) return (unsigned long)-1;
+    state = (struct inflate_state FAR *)strm->state;
+    return (unsigned long)(state->next - state->codes);
+}
diff --git a/xs/src/png/zlib/inflate.h b/xs/src/png/zlib/inflate.h
new file mode 100644
index 000000000..a46cce6b6
--- /dev/null
+++ b/xs/src/png/zlib/inflate.h
@@ -0,0 +1,125 @@
+/* inflate.h -- internal inflate state definition
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* define NO_GZIP when compiling if you want to disable gzip header and
+   trailer decoding by inflate().  NO_GZIP would be used to avoid linking in
+   the crc code when it is not needed.  For shared libraries, gzip decoding
+   should be left enabled. */
+#ifndef NO_GZIP
+#  define GUNZIP
+#endif
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+    HEAD = 16180,   /* i: waiting for magic header */
+    FLAGS,      /* i: waiting for method and flags (gzip) */
+    TIME,       /* i: waiting for modification time (gzip) */
+    OS,         /* i: waiting for extra flags and operating system (gzip) */
+    EXLEN,      /* i: waiting for extra length (gzip) */
+    EXTRA,      /* i: waiting for extra bytes (gzip) */
+    NAME,       /* i: waiting for end of file name (gzip) */
+    COMMENT,    /* i: waiting for end of comment (gzip) */
+    HCRC,       /* i: waiting for header crc (gzip) */
+    DICTID,     /* i: waiting for dictionary check value */
+    DICT,       /* waiting for inflateSetDictionary() call */
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        TYPEDO,     /* i: same, but skip check to exit inflate on new block */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        COPY_,      /* i/o: same as COPY below, but only first time in */
+        COPY,       /* i/o: waiting for input or output to copy stored block */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+        LENLENS,    /* i: waiting for code length code lengths */
+        CODELENS,   /* i: waiting for length/lit and distance code lengths */
+            LEN_,       /* i: same as LEN below, but only first time in */
+            LEN,        /* i: waiting for length/lit/eob code */
+            LENEXT,     /* i: waiting for length extra bits */
+            DIST,       /* i: waiting for distance code */
+            DISTEXT,    /* i: waiting for distance extra bits */
+            MATCH,      /* o: waiting for output space to copy string */
+            LIT,        /* o: waiting for output space to write literal */
+    CHECK,      /* i: waiting for 32-bit check value */
+    LENGTH,     /* i: waiting for 32-bit length (gzip) */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD,        /* got a data error -- remain here until reset */
+    MEM,        /* got an inflate() memory error -- remain here until reset */
+    SYNC        /* looking for synchronization bytes to restart inflate() */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to BAD or MEM on error -- not shown for clarity)
+
+    Process header:
+        HEAD -> (gzip) or (zlib) or (raw)
+        (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME -> COMMENT ->
+                  HCRC -> TYPE
+        (zlib) -> DICTID or TYPE
+        DICTID -> DICT -> TYPE
+        (raw) -> TYPEDO
+    Read deflate blocks:
+            TYPE -> TYPEDO -> STORED or TABLE or LEN_ or CHECK
+            STORED -> COPY_ -> COPY -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN_
+            LEN_ -> LEN
+    Read deflate codes in fixed or dynamic block:
+                LEN -> LENEXT or LIT or TYPE
+                LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
+                LIT -> LEN
+    Process trailer:
+        CHECK -> LENGTH -> DONE
+ */
+
+/* State maintained between inflate() calls -- approximately 7K bytes, not
+   including the allocated sliding window, which is up to 32K bytes. */
+struct inflate_state {
+    z_streamp strm;             /* pointer back to this zlib stream */
+    inflate_mode mode;          /* current inflate mode */
+    int last;                   /* true if processing last block */
+    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip,
+                                   bit 2 true to validate check value */
+    int havedict;               /* true if dictionary provided */
+    int flags;                  /* gzip header method and flags (0 if zlib) */
+    unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
+    unsigned long check;        /* protected copy of check value */
+    unsigned long total;        /* protected copy of output count */
+    gz_headerp head;            /* where to save gzip header information */
+        /* sliding window */
+    unsigned wbits;             /* log base 2 of requested window size */
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned wnext;             /* window write index */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+        /* bit accumulator */
+    unsigned long hold;         /* input bit accumulator */
+    unsigned bits;              /* number of bits in "in" */
+        /* for string and stored block copying */
+    unsigned length;            /* literal or length of data to copy */
+    unsigned offset;            /* distance back to copy string from */
+        /* for table and code decoding */
+    unsigned extra;             /* extra bits needed */
+        /* fixed and dynamic code tables */
+    code const FAR *lencode;    /* starting table for length/literal codes */
+    code const FAR *distcode;   /* starting table for distance codes */
+    unsigned lenbits;           /* index bits for lencode */
+    unsigned distbits;          /* index bits for distcode */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code FAR *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+    int sane;                   /* if false, allow invalid distance too far */
+    int back;                   /* bits back of last unprocessed length/lit */
+    unsigned was;               /* initial length of match */
+};
diff --git a/xs/src/png/zlib/inftrees.c b/xs/src/png/zlib/inftrees.c
new file mode 100644
index 000000000..2ea08fc13
--- /dev/null
+++ b/xs/src/png/zlib/inftrees.c
@@ -0,0 +1,304 @@
+/* inftrees.c -- generate Huffman trees for efficient decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+
+#define MAXBITS 15
+
+const char inflate_copyright[] =
+   " inflate 1.2.11 Copyright 1995-2017 Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/*
+   Build a set of tables to decode the provided canonical Huffman code.
+   The code lengths are lens[0..codes-1].  The result starts at *table,
+   whose indices are 0..2^bits-1.  work is a writable array of at least
+   lens shorts, which is used as a work area.  type is the type of code
+   to be generated, CODES, LENS, or DISTS.  On return, zero is success,
+   -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
+   on return points to the next available entry's address.  bits is the
+   requested root table index bits, and on return it is the actual root
+   table index bits.  It will differ if the request is greater than the
+   longest code or if it is less than the shortest code.
+ */
+int ZLIB_INTERNAL inflate_table(type, lens, codes, table, bits, work)
+codetype type;
+unsigned short FAR *lens;
+unsigned codes;
+code FAR * FAR *table;
+unsigned FAR *bits;
+unsigned short FAR *work;
+{
+    unsigned len;               /* a code's length in bits */
+    unsigned sym;               /* index of code symbols */
+    unsigned min, max;          /* minimum and maximum code lengths */
+    unsigned root;              /* number of index bits for root table */
+    unsigned curr;              /* number of index bits for current table */
+    unsigned drop;              /* code bits to drop for sub-table */
+    int left;                   /* number of prefix codes available */
+    unsigned used;              /* code entries in table used */
+    unsigned huff;              /* Huffman code */
+    unsigned incr;              /* for incrementing code, index */
+    unsigned fill;              /* index for replicating entries */
+    unsigned low;               /* low bits for current root entry */
+    unsigned mask;              /* mask for low root bits */
+    code here;                  /* table entry for duplication */
+    code FAR *next;             /* next available space in table */
+    const unsigned short FAR *base;     /* base value table to use */
+    const unsigned short FAR *extra;    /* extra bits table to use */
+    unsigned match;             /* use base and extra for symbol >= match */
+    unsigned short count[MAXBITS+1];    /* number of codes of each length */
+    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
+    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
+        16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 77, 202};
+    static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577, 0, 0};
+    static const unsigned short dext[32] = { /* Distance codes 0..29 extra */
+        16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
+        23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
+        28, 28, 29, 29, 64, 64};
+
+    /*
+       Process a set of code lengths to create a canonical Huffman code.  The
+       code lengths are lens[0..codes-1].  Each length corresponds to the
+       symbols 0..codes-1.  The Huffman code is generated by first sorting the
+       symbols by length from short to long, and retaining the symbol order
+       for codes with equal lengths.  Then the code starts with all zero bits
+       for the first code of the shortest length, and the codes are integer
+       increments for the same length, and zeros are appended as the length
+       increases.  For the deflate format, these bits are stored backwards
+       from their more natural integer increment ordering, and so when the
+       decoding tables are built in the large loop below, the integer codes
+       are incremented backwards.
+
+       This routine assumes, but does not check, that all of the entries in
+       lens[] are in the range 0..MAXBITS.  The caller must assure this.
+       1..MAXBITS is interpreted as that code length.  zero means that that
+       symbol does not occur in this code.
+
+       The codes are sorted by computing a count of codes for each length,
+       creating from that a table of starting indices for each length in the
+       sorted table, and then entering the symbols in order in the sorted
+       table.  The sorted table is work[], with that space being provided by
+       the caller.
+
+       The length counts are used for other purposes as well, i.e. finding
+       the minimum and maximum length codes, determining if there are any
+       codes at all, checking for a valid set of lengths, and looking ahead
+       at length counts to determine sub-table sizes when building the
+       decoding tables.
+     */
+
+    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
+    for (len = 0; len <= MAXBITS; len++)
+        count[len] = 0;
+    for (sym = 0; sym < codes; sym++)
+        count[lens[sym]]++;
+
+    /* bound code lengths, force root to be within code lengths */
+    root = *bits;
+    for (max = MAXBITS; max >= 1; max--)
+        if (count[max] != 0) break;
+    if (root > max) root = max;
+    if (max == 0) {                     /* no symbols to code at all */
+        here.op = (unsigned char)64;    /* invalid code marker */
+        here.bits = (unsigned char)1;
+        here.val = (unsigned short)0;
+        *(*table)++ = here;             /* make a table to force an error */
+        *(*table)++ = here;
+        *bits = 1;
+        return 0;     /* no symbols, but wait for decoding to report error */
+    }
+    for (min = 1; min < max; min++)
+        if (count[min] != 0) break;
+    if (root < min) root = min;
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;
+        left -= count[len];
+        if (left < 0) return -1;        /* over-subscribed */
+    }
+    if (left > 0 && (type == CODES || max != 1))
+        return -1;                      /* incomplete set */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + count[len];
+
+    /* sort symbols by length, by symbol order within each length */
+    for (sym = 0; sym < codes; sym++)
+        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;
+
+    /*
+       Create and fill in decoding tables.  In this loop, the table being
+       filled is at next and has curr index bits.  The code being used is huff
+       with length len.  That code is converted to an index by dropping drop
+       bits off of the bottom.  For codes where len is less than drop + curr,
+       those top drop + curr - len bits are incremented through all values to
+       fill the table with replicated entries.
+
+       root is the number of index bits for the root table.  When len exceeds
+       root, sub-tables are created pointed to by the root entry with an index
+       of the low root bits of huff.  This is saved in low to check for when a
+       new sub-table should be started.  drop is zero when the root table is
+       being filled, and drop is root when sub-tables are being filled.
+
+       When a new sub-table is needed, it is necessary to look ahead in the
+       code lengths to determine what size sub-table is needed.  The length
+       counts are used for this, and so count[] is decremented as codes are
+       entered in the tables.
+
+       used keeps track of how many table entries have been allocated from the
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftrees.h
+       for more information.
+
+       sym increments through all symbols, and the loop terminates when
+       all codes of length max, i.e. all codes, have been processed.  This
+       routine permits incomplete codes, so another loop after this one fills
+       in the rest of the decoding tables with invalid code markers.
+     */
+
+    /* set up for code type */
+    switch (type) {
+    case CODES:
+        base = extra = work;    /* dummy value--not used */
+        match = 20;
+        break;
+    case LENS:
+        base = lbase;
+        extra = lext;
+        match = 257;
+        break;
+    default:    /* DISTS */
+        base = dbase;
+        extra = dext;
+        match = 0;
+    }
+
+    /* initialize state for loop */
+    huff = 0;                   /* starting code */
+    sym = 0;                    /* starting code symbol */
+    len = min;                  /* starting code length */
+    next = *table;              /* current table to fill in */
+    curr = root;                /* current table index bits */
+    drop = 0;                   /* current bits to drop from code for index */
+    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
+    used = 1U << root;          /* use root table entries */
+    mask = used - 1;            /* mask for comparing low */
+
+    /* check available table space */
+    if ((type == LENS && used > ENOUGH_LENS) ||
+        (type == DISTS && used > ENOUGH_DISTS))
+        return 1;
+
+    /* process all codes and make table entries */
+    for (;;) {
+        /* create table entry */
+        here.bits = (unsigned char)(len - drop);
+        if (work[sym] + 1U < match) {
+            here.op = (unsigned char)0;
+            here.val = work[sym];
+        }
+        else if (work[sym] >= match) {
+            here.op = (unsigned char)(extra[work[sym] - match]);
+            here.val = base[work[sym] - match];
+        }
+        else {
+            here.op = (unsigned char)(32 + 64);         /* end of block */
+            here.val = 0;
+        }
+
+        /* replicate for those indices with low len bits equal to huff */
+        incr = 1U << (len - drop);
+        fill = 1U << curr;
+        min = fill;                 /* save offset to next table */
+        do {
+            fill -= incr;
+            next[(huff >> drop) + fill] = here;
+        } while (fill != 0);
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+
+        /* go to next symbol, update count, len */
+        sym++;
+        if (--(count[len]) == 0) {
+            if (len == max) break;
+            len = lens[work[sym]];
+        }
+
+        /* create new sub-table if needed */
+        if (len > root && (huff & mask) != low) {
+            /* if first time, transition to sub-tables */
+            if (drop == 0)
+                drop = root;
+
+            /* increment past last table */
+            next += min;            /* here min is 1 << curr */
+
+            /* determine length of next table */
+            curr = len - drop;
+            left = (int)(1 << curr);
+            while (curr + drop < max) {
+                left -= count[curr + drop];
+                if (left <= 0) break;
+                curr++;
+                left <<= 1;
+            }
+
+            /* check for enough space */
+            used += 1U << curr;
+            if ((type == LENS && used > ENOUGH_LENS) ||
+                (type == DISTS && used > ENOUGH_DISTS))
+                return 1;
+
+            /* point entry in root table to sub-table */
+            low = huff & mask;
+            (*table)[low].op = (unsigned char)curr;
+            (*table)[low].bits = (unsigned char)root;
+            (*table)[low].val = (unsigned short)(next - *table);
+        }
+    }
+
+    /* fill in remaining table entry if code is incomplete (guaranteed to have
+       at most one remaining entry, since if the code is incomplete, the
+       maximum code length that was allowed to get this far is one bit) */
+    if (huff != 0) {
+        here.op = (unsigned char)64;            /* invalid code marker */
+        here.bits = (unsigned char)(len - drop);
+        here.val = (unsigned short)0;
+        next[huff] = here;
+    }
+
+    /* set return parameters */
+    *table += used;
+    *bits = root;
+    return 0;
+}
diff --git a/xs/src/png/zlib/inftrees.h b/xs/src/png/zlib/inftrees.h
new file mode 100644
index 000000000..baa53a0b1
--- /dev/null
+++ b/xs/src/png/zlib/inftrees.h
@@ -0,0 +1,62 @@
+/* inftrees.h -- header to use inftrees.c
+ * Copyright (C) 1995-2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Structure for decoding tables.  Each entry provides either the
+   information needed to do the operation requested by the code that
+   indexed that table entry, or it provides a pointer to another
+   table that indexes more bits of the code.  op indicates whether
+   the entry is a pointer to another table, a literal, a length or
+   distance, an end-of-block, or an invalid code.  For a table
+   pointer, the low four bits of op is the number of index bits of
+   that table.  For a length or distance, the low four bits of op
+   is the number of extra bits to get after the code.  bits is
+   the number of bits in this code or part of the code to drop off
+   of the bit buffer.  val is the actual byte to output in the case
+   of a literal, the base length or distance, or the offset from
+   the current table to the next table.  Each entry is four bytes. */
+typedef struct {
+    unsigned char op;           /* operation, extra bits, table bits */
+    unsigned char bits;         /* bits in this part of the code */
+    unsigned short val;         /* offset in table or code value */
+} code;
+
+/* op values as set by inflate_table():
+    00000000 - literal
+    0000tttt - table link, tttt != 0 is the number of table index bits
+    0001eeee - length or distance, eeee is the number of extra bits
+    01100000 - end of block
+    01000000 - invalid code
+ */
+
+/* Maximum size of the dynamic table.  The maximum number of code structures is
+   1444, which is the sum of 852 for literal/length codes and 592 for distance
+   codes.  These values were found by exhaustive searches using the program
+   examples/enough.c found in the zlib distribtution.  The arguments to that
+   program are the number of symbols, the initial root table size, and the
+   maximum bit length of a code.  "enough 286 9 15" for literal/length codes
+   returns returns 852, and "enough 30 6 15" for distance codes returns 592.
+   The initial root table size (9 or 6) is found in the fifth argument of the
+   inflate_table() calls in inflate.c and infback.c.  If the root table size is
+   changed, then these maximum sizes would be need to be recalculated and
+   updated. */
+#define ENOUGH_LENS 852
+#define ENOUGH_DISTS 592
+#define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
+
+/* Type of code to build for inflate_table() */
+typedef enum {
+    CODES,
+    LENS,
+    DISTS
+} codetype;
+
+int ZLIB_INTERNAL inflate_table OF((codetype type, unsigned short FAR *lens,
+                             unsigned codes, code FAR * FAR *table,
+                             unsigned FAR *bits, unsigned short FAR *work));
diff --git a/xs/src/png/zlib/make_vms.com b/xs/src/png/zlib/make_vms.com
new file mode 100644
index 000000000..65e9d0cbc
--- /dev/null
+++ b/xs/src/png/zlib/make_vms.com
@@ -0,0 +1,867 @@
+$! make libz under VMS written by
+$! Martin P.J. Zinser
+$!
+$! In case of problems with the install you might contact me at
+$! zinser@zinser.no-ip.info(preferred) or
+$! martin.zinser@eurexchange.com (work)
+$!
+$! Make procedure history for Zlib
+$!
+$!------------------------------------------------------------------------------
+$! Version history
+$! 0.01 20060120 First version to receive a number
+$! 0.02 20061008 Adapt to new Makefile.in
+$! 0.03 20091224 Add support for large file check
+$! 0.04 20100110 Add new gzclose, gzlib, gzread, gzwrite
+$! 0.05 20100221 Exchange zlibdefs.h by zconf.h.in
+$! 0.06 20120111 Fix missing amiss_err, update zconf_h.in, fix new exmples
+$!               subdir path, update module search in makefile.in
+$! 0.07 20120115 Triggered by work done by Alexey Chupahin completly redesigned
+$!               shared image creation
+$! 0.08 20120219 Make it work on VAX again, pre-load missing symbols to shared
+$!               image
+$! 0.09 20120305 SMS.  P1 sets builder ("MMK", "MMS", " " (built-in)).
+$!               "" -> automatic, preference: MMK, MMS, built-in.
+$!
+$ on error then goto err_exit
+$!
+$ true  = 1
+$ false = 0
+$ tmpnam = "temp_" + f$getjpi("","pid")
+$ tt = tmpnam + ".txt"
+$ tc = tmpnam + ".c"
+$ th = tmpnam + ".h"
+$ define/nolog tconfig 'th'
+$ its_decc = false
+$ its_vaxc = false
+$ its_gnuc = false
+$ s_case   = False
+$!
+$! Setup variables holding "config" information
+$!
+$ Make    = "''p1'"
+$ name     = "Zlib"
+$ version  = "?.?.?"
+$ v_string = "ZLIB_VERSION"
+$ v_file   = "zlib.h"
+$ ccopt   = "/include = []"
+$ lopts   = ""
+$ dnsrl   = ""
+$ aconf_in_file = "zconf.h.in#zconf.h_in#zconf_h.in"
+$ conf_check_string = ""
+$ linkonly = false
+$ optfile  = name + ".opt"
+$ mapfile  = name + ".map"
+$ libdefs  = ""
+$ vax      = f$getsyi("HW_MODEL").lt.1024
+$ axp      = f$getsyi("HW_MODEL").ge.1024 .and. f$getsyi("HW_MODEL").lt.4096
+$ ia64     = f$getsyi("HW_MODEL").ge.4096
+$!
+$! 2012-03-05 SMS.
+$! Why is this needed?  And if it is needed, why not simply ".not. vax"?
+$!
+$!!! if axp .or. ia64 then  set proc/parse=extended
+$!
+$ whoami = f$parse(f$environment("Procedure"),,,,"NO_CONCEAL")
+$ mydef  = F$parse(whoami,,,"DEVICE")
+$ mydir  = f$parse(whoami,,,"DIRECTORY") - "]["
+$ myproc = f$parse(whoami,,,"Name") + f$parse(whoami,,,"type")
+$!
+$! Check for MMK/MMS
+$!
+$ if (Make .eqs. "")
+$ then
+$   If F$Search ("Sys$System:MMS.EXE") .nes. "" Then Make = "MMS"
+$   If F$Type (MMK) .eqs. "STRING" Then Make = "MMK"
+$ else
+$   Make = f$edit( Make, "trim")
+$ endif
+$!
+$ gosub find_version
+$!
+$  open/write topt tmp.opt
+$  open/write optf 'optfile'
+$!
+$ gosub check_opts
+$!
+$! Look for the compiler used
+$!
+$ gosub check_compiler
+$ close topt
+$ close optf
+$!
+$ if its_decc
+$ then
+$   ccopt = "/prefix=all" + ccopt
+$   if f$trnlnm("SYS") .eqs. ""
+$   then
+$     if axp
+$     then
+$       define sys sys$library:
+$     else
+$       ccopt = "/decc" + ccopt
+$       define sys decc$library_include:
+$     endif
+$   endif
+$!
+$! 2012-03-05 SMS.
+$! Why /NAMES = AS_IS?  Why not simply ".not. vax"?  And why not on VAX?
+$!
+$   if axp .or. ia64
+$   then
+$       ccopt = ccopt + "/name=as_is/opt=(inline=speed)"
+$       s_case = true
+$   endif
+$ endif
+$ if its_vaxc .or. its_gnuc
+$ then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ endif
+$!
+$! Build a fake configure input header
+$!
+$ open/write conf_hin config.hin
+$ write conf_hin "#undef _LARGEFILE64_SOURCE"
+$ close conf_hin
+$!
+$!
+$ i = 0
+$FIND_ACONF:
+$ fname = f$element(i,"#",aconf_in_file)
+$ if fname .eqs. "#" then goto AMISS_ERR
+$ if f$search(fname) .eqs. ""
+$ then
+$   i = i + 1
+$   goto find_aconf
+$ endif
+$ open/read/err=aconf_err aconf_in 'fname'
+$ open/write aconf zconf.h
+$ACONF_LOOP:
+$ read/end_of_file=aconf_exit aconf_in line
+$ work = f$edit(line, "compress,trim")
+$ if f$extract(0,6,work) .nes. "#undef"
+$ then
+$   if f$extract(0,12,work) .nes. "#cmakedefine"
+$   then
+$       write aconf line
+$   endif
+$ else
+$   cdef = f$element(1," ",work)
+$   gosub check_config
+$ endif
+$ goto aconf_loop
+$ACONF_EXIT:
+$ write aconf ""
+$ write aconf "/* VMS specifics added by make_vms.com: */"
+$ write aconf "#define VMS 1"
+$ write aconf "#include <unistd.h>"
+$ write aconf "#include <unixio.h>"
+$ write aconf "#ifdef _LARGEFILE"
+$ write aconf "# define off64_t __off64_t"
+$ write aconf "# define fopen64 fopen"
+$ write aconf "# define fseeko64 fseeko"
+$ write aconf "# define lseek64 lseek"
+$ write aconf "# define ftello64 ftell"
+$ write aconf "#endif"
+$ write aconf "#if !defined( __VAX) && (__CRTL_VER >= 70312000)"
+$ write aconf "# define HAVE_VSNPRINTF"
+$ write aconf "#endif"
+$ close aconf_in
+$ close aconf
+$ if f$search("''th'") .nes. "" then delete 'th';*
+$! Build the thing plain or with mms
+$!
+$ write sys$output "Compiling Zlib sources ..."
+$ if make.eqs.""
+$ then
+$   if (f$search( "example.obj;*") .nes. "") then delete example.obj;*
+$   if (f$search( "minigzip.obj;*") .nes. "") then delete minigzip.obj;*
+$   CALL MAKE adler32.OBJ "CC ''CCOPT' adler32" -
+                adler32.c zlib.h zconf.h
+$   CALL MAKE compress.OBJ "CC ''CCOPT' compress" -
+                compress.c zlib.h zconf.h
+$   CALL MAKE crc32.OBJ "CC ''CCOPT' crc32" -
+                crc32.c zlib.h zconf.h
+$   CALL MAKE deflate.OBJ "CC ''CCOPT' deflate" -
+                deflate.c deflate.h zutil.h zlib.h zconf.h
+$   CALL MAKE gzclose.OBJ "CC ''CCOPT' gzclose" -
+                gzclose.c zutil.h zlib.h zconf.h
+$   CALL MAKE gzlib.OBJ "CC ''CCOPT' gzlib" -
+                gzlib.c zutil.h zlib.h zconf.h
+$   CALL MAKE gzread.OBJ "CC ''CCOPT' gzread" -
+                gzread.c zutil.h zlib.h zconf.h
+$   CALL MAKE gzwrite.OBJ "CC ''CCOPT' gzwrite" -
+                gzwrite.c zutil.h zlib.h zconf.h
+$   CALL MAKE infback.OBJ "CC ''CCOPT' infback" -
+                infback.c zutil.h inftrees.h inflate.h inffast.h inffixed.h
+$   CALL MAKE inffast.OBJ "CC ''CCOPT' inffast" -
+                inffast.c zutil.h zlib.h zconf.h inffast.h
+$   CALL MAKE inflate.OBJ "CC ''CCOPT' inflate" -
+                inflate.c zutil.h zlib.h zconf.h infblock.h
+$   CALL MAKE inftrees.OBJ "CC ''CCOPT' inftrees" -
+                inftrees.c zutil.h zlib.h zconf.h inftrees.h
+$   CALL MAKE trees.OBJ "CC ''CCOPT' trees" -
+                trees.c deflate.h zutil.h zlib.h zconf.h
+$   CALL MAKE uncompr.OBJ "CC ''CCOPT' uncompr" -
+                uncompr.c zlib.h zconf.h
+$   CALL MAKE zutil.OBJ "CC ''CCOPT' zutil" -
+                zutil.c zutil.h zlib.h zconf.h
+$   write sys$output "Building Zlib ..."
+$   CALL MAKE libz.OLB "lib/crea libz.olb *.obj" *.OBJ
+$   write sys$output "Building example..."
+$   CALL MAKE example.OBJ "CC ''CCOPT' [.test]example" -
+                [.test]example.c zlib.h zconf.h
+$   call make example.exe "LINK example,libz.olb/lib" example.obj libz.olb
+$   write sys$output "Building minigzip..."
+$   CALL MAKE minigzip.OBJ "CC ''CCOPT' [.test]minigzip" -
+              [.test]minigzip.c zlib.h zconf.h
+$   call make minigzip.exe -
+              "LINK minigzip,libz.olb/lib" -
+              minigzip.obj libz.olb
+$ else
+$   gosub crea_mms
+$   write sys$output "Make ''name' ''version' with ''Make' "
+$   'make'
+$ endif
+$!
+$! Create shareable image
+$!
+$ gosub crea_olist
+$ write sys$output "Creating libzshr.exe"
+$ call map_2_shopt 'mapfile' 'optfile'
+$ LINK_'lopts'/SHARE=libzshr.exe modules.opt/opt,'optfile'/opt
+$ write sys$output "Zlib build completed"
+$ delete/nolog tmp.opt;*
+$ exit
+$AMISS_ERR:
+$ write sys$output "No source for config.hin found."
+$ write sys$output "Tried any of ''aconf_in_file'"
+$ goto err_exit
+$CC_ERR:
+$ write sys$output "C compiler required to build ''name'"
+$ goto err_exit
+$ERR_EXIT:
+$ set message/facil/ident/sever/text
+$ close/nolog optf
+$ close/nolog topt
+$ close/nolog aconf_in
+$ close/nolog aconf
+$ close/nolog out
+$ close/nolog min
+$ close/nolog mod
+$ close/nolog h_in
+$ write sys$output "Exiting..."
+$ exit 2
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE
+$!------------------------------------------------------------------------------
+$!
+$! Check command line options and set symbols accordingly
+$!
+$!------------------------------------------------------------------------------
+$! Version history
+$! 0.01 20041206 First version to receive a number
+$! 0.02 20060126 Add new "HELP" target
+$ CHECK_OPTS:
+$ i = 1
+$ OPT_LOOP:
+$ if i .lt. 9
+$ then
+$   cparm = f$edit(p'i',"upcase")
+$!
+$! Check if parameter actually contains something
+$!
+$   if f$edit(cparm,"trim") .nes. ""
+$   then
+$     if cparm .eqs. "DEBUG"
+$     then
+$       ccopt = ccopt + "/noopt/deb"
+$       lopts = lopts + "/deb"
+$     endif
+$     if f$locate("CCOPT=",cparm) .lt. f$length(cparm)
+$     then
+$       start = f$locate("=",cparm) + 1
+$       len   = f$length(cparm) - start
+$       ccopt = ccopt + f$extract(start,len,cparm)
+$       if f$locate("AS_IS",f$edit(ccopt,"UPCASE")) .lt. f$length(ccopt) -
+          then s_case = true
+$     endif
+$     if cparm .eqs. "LINK" then linkonly = true
+$     if f$locate("LOPTS=",cparm) .lt. f$length(cparm)
+$     then
+$       start = f$locate("=",cparm) + 1
+$       len   = f$length(cparm) - start
+$       lopts = lopts + f$extract(start,len,cparm)
+$     endif
+$     if f$locate("CC=",cparm) .lt. f$length(cparm)
+$     then
+$       start  = f$locate("=",cparm) + 1
+$       len    = f$length(cparm) - start
+$       cc_com = f$extract(start,len,cparm)
+        if (cc_com .nes. "DECC") .and. -
+           (cc_com .nes. "VAXC") .and. -
+           (cc_com .nes. "GNUC")
+$       then
+$         write sys$output "Unsupported compiler choice ''cc_com' ignored"
+$         write sys$output "Use DECC, VAXC, or GNUC instead"
+$       else
+$         if cc_com .eqs. "DECC" then its_decc = true
+$         if cc_com .eqs. "VAXC" then its_vaxc = true
+$         if cc_com .eqs. "GNUC" then its_gnuc = true
+$       endif
+$     endif
+$     if f$locate("MAKE=",cparm) .lt. f$length(cparm)
+$     then
+$       start  = f$locate("=",cparm) + 1
+$       len    = f$length(cparm) - start
+$       mmks = f$extract(start,len,cparm)
+$       if (mmks .eqs. "MMK") .or. (mmks .eqs. "MMS")
+$       then
+$         make = mmks
+$       else
+$         write sys$output "Unsupported make choice ''mmks' ignored"
+$         write sys$output "Use MMK or MMS instead"
+$       endif
+$     endif
+$     if cparm .eqs. "HELP" then gosub bhelp
+$   endif
+$   i = i + 1
+$   goto opt_loop
+$ endif
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Look for the compiler used
+$!
+$! Version history
+$! 0.01 20040223 First version to receive a number
+$! 0.02 20040229 Save/set value of decc$no_rooted_search_lists
+$! 0.03 20060202 Extend handling of GNU C
+$! 0.04 20090402 Compaq -> hp
+$CHECK_COMPILER:
+$ if (.not. (its_decc .or. its_vaxc .or. its_gnuc))
+$ then
+$   its_decc = (f$search("SYS$SYSTEM:DECC$COMPILER.EXE") .nes. "")
+$   its_vaxc = .not. its_decc .and. (F$Search("SYS$System:VAXC.Exe") .nes. "")
+$   its_gnuc = .not. (its_decc .or. its_vaxc) .and. (f$trnlnm("gnu_cc") .nes. "")
+$ endif
+$!
+$! Exit if no compiler available
+$!
+$ if (.not. (its_decc .or. its_vaxc .or. its_gnuc))
+$ then goto CC_ERR
+$ else
+$   if its_decc
+$   then
+$     write sys$output "CC compiler check ... hp C"
+$     if f$trnlnm("decc$no_rooted_search_lists") .nes. ""
+$     then
+$       dnrsl = f$trnlnm("decc$no_rooted_search_lists")
+$     endif
+$     define/nolog decc$no_rooted_search_lists 1
+$   else
+$     if its_vaxc then write sys$output "CC compiler check ... VAX C"
+$     if its_gnuc
+$     then
+$         write sys$output "CC compiler check ... GNU C"
+$         if f$trnlnm(topt) then write topt "gnu_cc:[000000]gcclib.olb/lib"
+$         if f$trnlnm(optf) then write optf "gnu_cc:[000000]gcclib.olb/lib"
+$         cc = "gcc"
+$     endif
+$     if f$trnlnm(topt) then write topt "sys$share:vaxcrtl.exe/share"
+$     if f$trnlnm(optf) then write optf "sys$share:vaxcrtl.exe/share"
+$   endif
+$ endif
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! If MMS/MMK are available dump out the descrip.mms if required
+$!
+$CREA_MMS:
+$ write sys$output "Creating descrip.mms..."
+$ create descrip.mms
+$ open/append out descrip.mms
+$ copy sys$input: out
+$ deck
+# descrip.mms: MMS description file for building zlib on VMS
+# written by Martin P.J. Zinser
+# <zinser@zinser.no-ip.info or martin.zinser@eurexchange.com>
+
+OBJS = adler32.obj, compress.obj, crc32.obj, gzclose.obj, gzlib.obj\
+       gzread.obj, gzwrite.obj, uncompr.obj, infback.obj\
+       deflate.obj, trees.obj, zutil.obj, inflate.obj, \
+       inftrees.obj, inffast.obj
+
+$ eod
+$ write out "CFLAGS=", ccopt
+$ write out "LOPTS=", lopts
+$ write out "all : example.exe minigzip.exe libz.olb"
+$ copy sys$input: out
+$ deck
+        @ write sys$output " Example applications available"
+
+libz.olb : libz.olb($(OBJS))
+	@ write sys$output " libz available"
+
+example.exe : example.obj libz.olb
+              link $(LOPTS) example,libz.olb/lib
+
+minigzip.exe : minigzip.obj libz.olb
+              link $(LOPTS) minigzip,libz.olb/lib
+
+clean :
+	delete *.obj;*,libz.olb;*,*.opt;*,*.exe;*
+
+
+# Other dependencies.
+adler32.obj  : adler32.c zutil.h zlib.h zconf.h
+compress.obj : compress.c zlib.h zconf.h
+crc32.obj    : crc32.c zutil.h zlib.h zconf.h
+deflate.obj  : deflate.c deflate.h zutil.h zlib.h zconf.h
+example.obj  : [.test]example.c zlib.h zconf.h
+gzclose.obj  : gzclose.c zutil.h zlib.h zconf.h
+gzlib.obj    : gzlib.c zutil.h zlib.h zconf.h
+gzread.obj   : gzread.c zutil.h zlib.h zconf.h
+gzwrite.obj  : gzwrite.c zutil.h zlib.h zconf.h
+inffast.obj  : inffast.c zutil.h zlib.h zconf.h inftrees.h inffast.h
+inflate.obj  : inflate.c zutil.h zlib.h zconf.h
+inftrees.obj : inftrees.c zutil.h zlib.h zconf.h inftrees.h
+minigzip.obj : [.test]minigzip.c zlib.h zconf.h
+trees.obj    : trees.c deflate.h zutil.h zlib.h zconf.h
+uncompr.obj  : uncompr.c zlib.h zconf.h
+zutil.obj    : zutil.c zutil.h zlib.h zconf.h
+infback.obj  : infback.c zutil.h inftrees.h inflate.h inffast.h inffixed.h
+$ eod
+$ close out
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Read list of core library sources from makefile.in and create options
+$! needed to build shareable image
+$!
+$CREA_OLIST:
+$ open/read min makefile.in
+$ open/write mod modules.opt
+$ src_check_list = "OBJZ =#OBJG ="
+$MRLOOP:
+$ read/end=mrdone min rec
+$ i = 0
+$SRC_CHECK_LOOP:
+$ src_check = f$element(i, "#", src_check_list)
+$ i = i+1
+$ if src_check .eqs. "#" then goto mrloop
+$ if (f$extract(0,6,rec) .nes. src_check) then goto src_check_loop
+$ rec = rec - src_check
+$ gosub extra_filnam
+$ if (f$element(1,"\",rec) .eqs. "\") then goto mrloop
+$MRSLOOP:
+$ read/end=mrdone min rec
+$ gosub extra_filnam
+$ if (f$element(1,"\",rec) .nes. "\") then goto mrsloop
+$MRDONE:
+$ close min
+$ close mod
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Take record extracted in crea_olist and split it into single filenames
+$!
+$EXTRA_FILNAM:
+$ myrec = f$edit(rec - "\", "trim,compress")
+$ i = 0
+$FELOOP:
+$ srcfil = f$element(i," ", myrec)
+$ if (srcfil .nes. " ")
+$ then
+$   write mod f$parse(srcfil,,,"NAME"), ".obj"
+$   i = i + 1
+$   goto feloop
+$ endif
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Find current Zlib version number
+$!
+$FIND_VERSION:
+$ open/read h_in 'v_file'
+$hloop:
+$ read/end=hdone h_in rec
+$ rec = f$edit(rec,"TRIM")
+$ if (f$extract(0,1,rec) .nes. "#") then goto hloop
+$ rec = f$edit(rec - "#", "TRIM")
+$ if f$element(0," ",rec) .nes. "define" then goto hloop
+$ if f$element(1," ",rec) .eqs. v_string
+$ then
+$   version = 'f$element(2," ",rec)'
+$   goto hdone
+$ endif
+$ goto hloop
+$hdone:
+$ close h_in
+$ return
+$!------------------------------------------------------------------------------
+$!
+$CHECK_CONFIG:
+$!
+$ in_ldef = f$locate(cdef,libdefs)
+$ if (in_ldef .lt. f$length(libdefs))
+$ then
+$   write aconf "#define ''cdef' 1"
+$   libdefs = f$extract(0,in_ldef,libdefs) + -
+              f$extract(in_ldef + f$length(cdef) + 1, -
+                        f$length(libdefs) - in_ldef - f$length(cdef) - 1, -
+                        libdefs)
+$ else
+$   if (f$type('cdef') .eqs. "INTEGER")
+$   then
+$     write aconf "#define ''cdef' ", 'cdef'
+$   else
+$     if (f$type('cdef') .eqs. "STRING")
+$     then
+$       write aconf "#define ''cdef' ", """", '''cdef'', """"
+$     else
+$       gosub check_cc_def
+$     endif
+$   endif
+$ endif
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Check if this is a define relating to the properties of the C/C++
+$! compiler
+$!
+$ CHECK_CC_DEF:
+$ if (cdef .eqs. "_LARGEFILE64_SOURCE")
+$ then
+$   copy sys$input: 'tc'
+$   deck
+#include "tconfig"
+#define _LARGEFILE
+#include <stdio.h>
+
+int main(){
+FILE *fp;
+  fp = fopen("temp.txt","r");
+  fseeko(fp,1,SEEK_SET);
+  fclose(fp);
+}
+
+$   eod
+$   test_inv = false
+$   comm_h = false
+$   gosub cc_prop_check
+$   return
+$ endif
+$ write aconf "/* ", line, " */"
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Check for properties of C/C++ compiler
+$!
+$! Version history
+$! 0.01 20031020 First version to receive a number
+$! 0.02 20031022 Added logic for defines with value
+$! 0.03 20040309 Make sure local config file gets not deleted
+$! 0.04 20041230 Also write include for configure run
+$! 0.05 20050103 Add processing of "comment defines"
+$CC_PROP_CHECK:
+$ cc_prop = true
+$ is_need = false
+$ is_need = (f$extract(0,4,cdef) .eqs. "NEED") .or. (test_inv .eq. true)
+$ if f$search(th) .eqs. "" then create 'th'
+$ set message/nofac/noident/nosever/notext
+$ on error then continue
+$ cc 'tmpnam'
+$ if .not. ($status)  then cc_prop = false
+$ on error then continue
+$! The headers might lie about the capabilities of the RTL
+$ link 'tmpnam',tmp.opt/opt
+$ if .not. ($status)  then cc_prop = false
+$ set message/fac/ident/sever/text
+$ on error then goto err_exit
+$ delete/nolog 'tmpnam'.*;*/exclude='th'
+$ if (cc_prop .and. .not. is_need) .or. -
+     (.not. cc_prop .and. is_need)
+$ then
+$   write sys$output "Checking for ''cdef'... yes"
+$   if f$type('cdef_val'_yes) .nes. ""
+$   then
+$     if f$type('cdef_val'_yes) .eqs. "INTEGER" -
+         then call write_config f$fao("#define !AS !UL",cdef,'cdef_val'_yes)
+$     if f$type('cdef_val'_yes) .eqs. "STRING" -
+         then call write_config f$fao("#define !AS !AS",cdef,'cdef_val'_yes)
+$   else
+$     call write_config f$fao("#define !AS 1",cdef)
+$   endif
+$   if (cdef .eqs. "HAVE_FSEEKO") .or. (cdef .eqs. "_LARGE_FILES") .or. -
+       (cdef .eqs. "_LARGEFILE64_SOURCE") then -
+      call write_config f$string("#define _LARGEFILE 1")
+$ else
+$   write sys$output "Checking for ''cdef'... no"
+$   if (comm_h)
+$   then
+      call write_config f$fao("/* !AS */",line)
+$   else
+$     if f$type('cdef_val'_no) .nes. ""
+$     then
+$       if f$type('cdef_val'_no) .eqs. "INTEGER" -
+           then call write_config f$fao("#define !AS !UL",cdef,'cdef_val'_no)
+$       if f$type('cdef_val'_no) .eqs. "STRING" -
+           then call write_config f$fao("#define !AS !AS",cdef,'cdef_val'_no)
+$     else
+$       call write_config f$fao("#undef !AS",cdef)
+$     endif
+$   endif
+$ endif
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Check for properties of C/C++ compiler with multiple result values
+$!
+$! Version history
+$! 0.01 20040127 First version
+$! 0.02 20050103 Reconcile changes from cc_prop up to version 0.05
+$CC_MPROP_CHECK:
+$ cc_prop = true
+$ i    = 1
+$ idel = 1
+$ MT_LOOP:
+$ if f$type(result_'i') .eqs. "STRING"
+$ then
+$   set message/nofac/noident/nosever/notext
+$   on error then continue
+$   cc 'tmpnam'_'i'
+$   if .not. ($status)  then cc_prop = false
+$   on error then continue
+$! The headers might lie about the capabilities of the RTL
+$   link 'tmpnam'_'i',tmp.opt/opt
+$   if .not. ($status)  then cc_prop = false
+$   set message/fac/ident/sever/text
+$   on error then goto err_exit
+$   delete/nolog 'tmpnam'_'i'.*;*
+$   if (cc_prop)
+$   then
+$     write sys$output "Checking for ''cdef'... ", mdef_'i'
+$     if f$type(mdef_'i') .eqs. "INTEGER" -
+         then call write_config f$fao("#define !AS !UL",cdef,mdef_'i')
+$     if f$type('cdef_val'_yes) .eqs. "STRING" -
+         then call write_config f$fao("#define !AS !AS",cdef,mdef_'i')
+$     goto msym_clean
+$   else
+$     i = i + 1
+$     goto mt_loop
+$   endif
+$ endif
+$ write sys$output "Checking for ''cdef'... no"
+$ call write_config f$fao("#undef !AS",cdef)
+$ MSYM_CLEAN:
+$ if (idel .le. msym_max)
+$ then
+$   delete/sym mdef_'idel'
+$   idel = idel + 1
+$   goto msym_clean
+$ endif
+$ return
+$!------------------------------------------------------------------------------
+$!
+$! Write configuration to both permanent and temporary config file
+$!
+$! Version history
+$! 0.01 20031029 First version to receive a number
+$!
+$WRITE_CONFIG: SUBROUTINE
+$  write aconf 'p1'
+$  open/append confh 'th'
+$  write confh 'p1'
+$  close confh
+$ENDSUBROUTINE
+$!------------------------------------------------------------------------------
+$!
+$! Analyze the project map file and create the symbol vector for a shareable
+$! image from it
+$!
+$! Version history
+$! 0.01 20120128 First version
+$! 0.02 20120226 Add pre-load logic
+$!
+$ MAP_2_SHOPT: Subroutine
+$!
+$ SAY := "WRITE_ SYS$OUTPUT"
+$!
+$ IF F$SEARCH("''P1'") .EQS. ""
+$ THEN
+$    SAY "MAP_2_SHOPT-E-NOSUCHFILE:  Error, inputfile ''p1' not available"
+$    goto exit_m2s
+$ ENDIF
+$ IF "''P2'" .EQS. ""
+$ THEN
+$    SAY "MAP_2_SHOPT:  Error, no output file provided"
+$    goto exit_m2s
+$ ENDIF
+$!
+$ module1 = "deflate#deflateEnd#deflateInit_#deflateParams#deflateSetDictionary"
+$ module2 = "gzclose#gzerror#gzgetc#gzgets#gzopen#gzprintf#gzputc#gzputs#gzread"
+$ module3 = "gzseek#gztell#inflate#inflateEnd#inflateInit_#inflateSetDictionary"
+$ module4 = "inflateSync#uncompress#zlibVersion#compress"
+$ open/read map 'p1
+$ if axp .or. ia64
+$ then
+$     open/write aopt a.opt
+$     open/write bopt b.opt
+$     write aopt " CASE_SENSITIVE=YES"
+$     write bopt "SYMBOL_VECTOR= (-"
+$     mod_sym_num = 1
+$ MOD_SYM_LOOP:
+$     if f$type(module'mod_sym_num') .nes. ""
+$     then
+$         mod_in = 0
+$ MOD_SYM_IN:
+$         shared_proc = f$element(mod_in, "#", module'mod_sym_num')
+$         if shared_proc .nes. "#"
+$         then
+$             write aopt f$fao(" symbol_vector=(!AS/!AS=PROCEDURE)",-
+        		       f$edit(shared_proc,"upcase"),shared_proc)
+$             write bopt f$fao("!AS=PROCEDURE,-",shared_proc)
+$             mod_in = mod_in + 1
+$             goto mod_sym_in
+$         endif
+$         mod_sym_num = mod_sym_num + 1
+$         goto mod_sym_loop
+$     endif
+$MAP_LOOP:
+$     read/end=map_end map line
+$     if (f$locate("{",line).lt. f$length(line)) .or. -
+         (f$locate("global:", line) .lt. f$length(line))
+$     then
+$         proc = true
+$         goto map_loop
+$     endif
+$     if f$locate("}",line).lt. f$length(line) then proc = false
+$     if f$locate("local:", line) .lt. f$length(line) then proc = false
+$     if proc
+$     then
+$         shared_proc = f$edit(line,"collapse")
+$         chop_semi = f$locate(";", shared_proc)
+$         if chop_semi .lt. f$length(shared_proc) then -
+              shared_proc = f$extract(0, chop_semi, shared_proc)
+$         write aopt f$fao(" symbol_vector=(!AS/!AS=PROCEDURE)",-
+        			 f$edit(shared_proc,"upcase"),shared_proc)
+$         write bopt f$fao("!AS=PROCEDURE,-",shared_proc)
+$     endif
+$     goto map_loop
+$MAP_END:
+$     close/nolog aopt
+$     close/nolog bopt
+$     open/append libopt 'p2'
+$     open/read aopt a.opt
+$     open/read bopt b.opt
+$ALOOP:
+$     read/end=aloop_end aopt line
+$     write libopt line
+$     goto aloop
+$ALOOP_END:
+$     close/nolog aopt
+$     sv = ""
+$BLOOP:
+$     read/end=bloop_end bopt svn
+$     if (svn.nes."")
+$     then
+$        if (sv.nes."") then write libopt sv
+$        sv = svn
+$     endif
+$     goto bloop
+$BLOOP_END:
+$     write libopt f$extract(0,f$length(sv)-2,sv), "-"
+$     write libopt ")"
+$     close/nolog bopt
+$     delete/nolog/noconf a.opt;*,b.opt;*
+$ else
+$     if vax
+$     then
+$     open/append libopt 'p2'
+$     mod_sym_num = 1
+$ VMOD_SYM_LOOP:
+$     if f$type(module'mod_sym_num') .nes. ""
+$     then
+$         mod_in = 0
+$ VMOD_SYM_IN:
+$         shared_proc = f$element(mod_in, "#", module'mod_sym_num')
+$         if shared_proc .nes. "#"
+$         then
+$     	      write libopt f$fao("UNIVERSAL=!AS",-
+      	  			     f$edit(shared_proc,"upcase"))
+$             mod_in = mod_in + 1
+$             goto vmod_sym_in
+$         endif
+$         mod_sym_num = mod_sym_num + 1
+$         goto vmod_sym_loop
+$     endif
+$VMAP_LOOP:
+$     	  read/end=vmap_end map line
+$     	  if (f$locate("{",line).lt. f$length(line)) .or. -
+   	      (f$locate("global:", line) .lt. f$length(line))
+$     	  then
+$     	      proc = true
+$     	      goto vmap_loop
+$     	  endif
+$     	  if f$locate("}",line).lt. f$length(line) then proc = false
+$     	  if f$locate("local:", line) .lt. f$length(line) then proc = false
+$     	  if proc
+$     	  then
+$     	      shared_proc = f$edit(line,"collapse")
+$     	      chop_semi = f$locate(";", shared_proc)
+$     	      if chop_semi .lt. f$length(shared_proc) then -
+      	  	  shared_proc = f$extract(0, chop_semi, shared_proc)
+$     	      write libopt f$fao("UNIVERSAL=!AS",-
+      	  			     f$edit(shared_proc,"upcase"))
+$     	  endif
+$     	  goto vmap_loop
+$VMAP_END:
+$     else
+$         write sys$output "Unknown Architecture (Not VAX, AXP, or IA64)"
+$         write sys$output "No options file created"
+$     endif
+$ endif
+$ EXIT_M2S:
+$ close/nolog map
+$ close/nolog libopt
+$ endsubroutine
diff --git a/xs/src/png/zlib/msdos/Makefile.bor b/xs/src/png/zlib/msdos/Makefile.bor
new file mode 100644
index 000000000..3d12a2c25
--- /dev/null
+++ b/xs/src/png/zlib/msdos/Makefile.bor
@@ -0,0 +1,115 @@
+# Makefile for zlib
+# Borland C++
+# Last updated: 15-Mar-2003
+
+# To use, do "make -fmakefile.bor"
+# To compile in small model, set below: MODEL=s
+
+# WARNING: the small model is supported but only for small values of
+# MAX_WBITS and MAX_MEM_LEVEL. For example:
+#    -DMAX_WBITS=11 -DDEF_WBITS=11 -DMAX_MEM_LEVEL=3
+# If you wish to reduce the memory requirements (default 256K for big
+# objects plus a few K), you can add to the LOC macro below:
+#   -DMAX_MEM_LEVEL=7 -DMAX_WBITS=14
+# See zconf.h for details about the memory requirements.
+
+# ------------ Turbo C++, Borland C++ ------------
+
+#    Optional nonstandard preprocessor flags (e.g. -DMAX_MEM_LEVEL=7)
+#    should be added to the environment via "set LOCAL_ZLIB=-DFOO" or added
+#    to the declaration of LOC here:
+LOC = $(LOCAL_ZLIB)
+
+# type for CPU required: 0: 8086, 1: 80186, 2: 80286, 3: 80386, etc.
+CPU_TYP = 0
+
+# memory model: one of s, m, c, l (small, medium, compact, large)
+MODEL=l
+
+# replace bcc with tcc for Turbo C++ 1.0, with bcc32 for the 32 bit version
+CC=bcc
+LD=bcc
+AR=tlib
+
+# compiler flags
+# replace "-O2" by "-O -G -a -d" for Turbo C++ 1.0
+CFLAGS=-O2 -Z -m$(MODEL) $(LOC)
+
+LDFLAGS=-m$(MODEL) -f-
+
+
+# variables
+ZLIB_LIB = zlib_$(MODEL).lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+clean:
+	-del *.obj
+	-del *.lib
+	-del *.exe
+	-del zlib_*.bak
+	-del foo.gz
diff --git a/xs/src/png/zlib/msdos/Makefile.dj2 b/xs/src/png/zlib/msdos/Makefile.dj2
new file mode 100644
index 000000000..59d2037d6
--- /dev/null
+++ b/xs/src/png/zlib/msdos/Makefile.dj2
@@ -0,0 +1,104 @@
+# Makefile for zlib.  Modified for djgpp v2.0 by F. J. Donahoe, 3/15/96.
+# Copyright (C) 1995-1998 Jean-loup Gailly.
+# For conditions of distribution and use, see copyright notice in zlib.h
+
+# To compile, or to compile and test, type:
+#
+#   make -fmakefile.dj2;  make test -fmakefile.dj2
+#
+# To install libz.a, zconf.h and zlib.h in the djgpp directories, type:
+#
+#    make install -fmakefile.dj2
+#
+# after first defining LIBRARY_PATH and INCLUDE_PATH in djgpp.env as
+# in the sample below if the pattern of the DJGPP distribution is to
+# be followed.  Remember that, while <sp>'es around <=> are ignored in
+# makefiles, they are *not* in batch files or in djgpp.env.
+# - - - - -
+# [make]
+# INCLUDE_PATH=%\>;INCLUDE_PATH%%\DJDIR%\include
+# LIBRARY_PATH=%\>;LIBRARY_PATH%%\DJDIR%\lib
+# BUTT=-m486
+# - - - - -
+# Alternately, these variables may be defined below, overriding the values
+# in djgpp.env, as
+# INCLUDE_PATH=c:\usr\include
+# LIBRARY_PATH=c:\usr\lib
+
+CC=gcc
+
+#CFLAGS=-MMD -O
+#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
+#CFLAGS=-MMD -g -DZLIB_DEBUG
+CFLAGS=-MMD -O3 $(BUTT) -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
+             -Wstrict-prototypes -Wmissing-prototypes
+
+# If cp.exe is available, replace "copy /Y" with "cp -fp" .
+CP=copy /Y
+# If gnu install.exe is available, replace $(CP) with ginstall.
+INSTALL=$(CP)
+# The default value of RM is "rm -f."  If "rm.exe" is found, comment out:
+RM=del
+LDLIBS=-L. -lz
+LD=$(CC) -s -o
+LDSHARED=$(CC)
+
+INCL=zlib.h zconf.h
+LIBS=libz.a
+
+AR=ar rcs
+
+prefix=/usr/local
+exec_prefix = $(prefix)
+
+OBJS = adler32.o compress.o crc32.o gzclose.o gzlib.o gzread.o gzwrite.o \
+       uncompr.o deflate.o trees.o zutil.o inflate.o infback.o inftrees.o inffast.o
+
+OBJA =
+# to use the asm code: make OBJA=match.o
+
+TEST_OBJS = example.o minigzip.o
+
+all: example.exe minigzip.exe
+
+check: test
+test: all
+	./example
+	echo hello world | .\minigzip | .\minigzip -d
+
+%.o : %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+libz.a: $(OBJS) $(OBJA)
+	$(AR) $@ $(OBJS) $(OBJA)
+
+%.exe : %.o $(LIBS)
+	$(LD) $@ $< $(LDLIBS)
+
+# INCLUDE_PATH and LIBRARY_PATH were set for [make] in djgpp.env .
+
+.PHONY : uninstall clean
+
+install: $(INCL) $(LIBS)
+	-@if not exist $(INCLUDE_PATH)\nul mkdir $(INCLUDE_PATH)
+	-@if not exist $(LIBRARY_PATH)\nul mkdir $(LIBRARY_PATH)
+	$(INSTALL) zlib.h $(INCLUDE_PATH)
+	$(INSTALL) zconf.h $(INCLUDE_PATH)
+	$(INSTALL) libz.a $(LIBRARY_PATH)
+
+uninstall:
+	$(RM) $(INCLUDE_PATH)\zlib.h
+	$(RM) $(INCLUDE_PATH)\zconf.h
+	$(RM) $(LIBRARY_PATH)\libz.a
+
+clean:
+	$(RM) *.d
+	$(RM) *.o
+	$(RM) *.exe
+	$(RM) libz.a
+	$(RM) foo.gz
+
+DEPS := $(wildcard *.d)
+ifneq ($(DEPS),)
+include $(DEPS)
+endif
diff --git a/xs/src/png/zlib/msdos/Makefile.emx b/xs/src/png/zlib/msdos/Makefile.emx
new file mode 100644
index 000000000..e30f67bed
--- /dev/null
+++ b/xs/src/png/zlib/msdos/Makefile.emx
@@ -0,0 +1,69 @@
+# Makefile for zlib.  Modified for emx 0.9c by Chr. Spieler, 6/17/98.
+# Copyright (C) 1995-1998 Jean-loup Gailly.
+# For conditions of distribution and use, see copyright notice in zlib.h
+
+# To compile, or to compile and test, type:
+#
+#   make -fmakefile.emx;  make test -fmakefile.emx
+#
+
+CC=gcc
+
+#CFLAGS=-MMD -O
+#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
+#CFLAGS=-MMD -g -DZLIB_DEBUG
+CFLAGS=-MMD -O3 $(BUTT) -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
+             -Wstrict-prototypes -Wmissing-prototypes
+
+# If cp.exe is available, replace "copy /Y" with "cp -fp" .
+CP=copy /Y
+# If gnu install.exe is available, replace $(CP) with ginstall.
+INSTALL=$(CP)
+# The default value of RM is "rm -f."  If "rm.exe" is found, comment out:
+RM=del
+LDLIBS=-L. -lzlib
+LD=$(CC) -s -o
+LDSHARED=$(CC)
+
+INCL=zlib.h zconf.h
+LIBS=zlib.a
+
+AR=ar rcs
+
+prefix=/usr/local
+exec_prefix = $(prefix)
+
+OBJS = adler32.o compress.o crc32.o gzclose.o gzlib.o gzread.o gzwrite.o \
+       uncompr.o deflate.o trees.o zutil.o inflate.o infback.o inftrees.o inffast.o
+
+TEST_OBJS = example.o minigzip.o
+
+all: example.exe minigzip.exe
+
+test: all
+	./example
+	echo hello world | .\minigzip | .\minigzip -d
+
+%.o : %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+zlib.a: $(OBJS)
+	$(AR) $@ $(OBJS)
+
+%.exe : %.o $(LIBS)
+	$(LD) $@ $< $(LDLIBS)
+
+
+.PHONY : clean
+
+clean:
+	$(RM) *.d
+	$(RM) *.o
+	$(RM) *.exe
+	$(RM) zlib.a
+	$(RM) foo.gz
+
+DEPS := $(wildcard *.d)
+ifneq ($(DEPS),)
+include $(DEPS)
+endif
diff --git a/xs/src/png/zlib/msdos/Makefile.msc b/xs/src/png/zlib/msdos/Makefile.msc
new file mode 100644
index 000000000..ae8378615
--- /dev/null
+++ b/xs/src/png/zlib/msdos/Makefile.msc
@@ -0,0 +1,112 @@
+# Makefile for zlib
+# Microsoft C 5.1 or later
+# Last updated: 19-Mar-2003
+
+# To use, do "make makefile.msc"
+# To compile in small model, set below: MODEL=S
+
+# If you wish to reduce the memory requirements (default 256K for big
+# objects plus a few K), you can add to the LOC macro below:
+#   -DMAX_MEM_LEVEL=7 -DMAX_WBITS=14
+# See zconf.h for details about the memory requirements.
+
+# ------------- Microsoft C 5.1 and later -------------
+
+#    Optional nonstandard preprocessor flags (e.g. -DMAX_MEM_LEVEL=7)
+#    should be added to the environment via "set LOCAL_ZLIB=-DFOO" or added
+#    to the declaration of LOC here:
+LOC = $(LOCAL_ZLIB)
+
+# Type for CPU required: 0: 8086, 1: 80186, 2: 80286, 3: 80386, etc.
+CPU_TYP = 0
+
+# Memory model: one of S, M, C, L (small, medium, compact, large)
+MODEL=L
+
+CC=cl
+CFLAGS=-nologo -A$(MODEL) -G$(CPU_TYP) -W3 -Oait -Gs $(LOC)
+#-Ox generates bad code with MSC 5.1
+LIB_CFLAGS=-Zl $(CFLAGS)
+
+LD=link
+LDFLAGS=/noi/e/st:0x1500/noe/farcall/packcode
+# "/farcall/packcode" are only useful for `large code' memory models
+# but should be a "no-op" for small code models.
+
+
+# variables
+ZLIB_LIB = zlib_$(MODEL).lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+
+
+# targets
+all:  $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(LIB_CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+	$(CC) -c $(CFLAGS) $*.c
+
+
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	if exist $(ZLIB_LIB) del $(ZLIB_LIB)
+	lib $(ZLIB_LIB) $(OBJ1);
+	lib $(ZLIB_LIB) $(OBJ2);
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj,,,$(ZLIB_LIB);
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj,,,$(ZLIB_LIB);
+
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+clean:
+	-del *.obj
+	-del *.lib
+	-del *.exe
+	-del *.map
+	-del zlib_*.bak
+	-del foo.gz
diff --git a/xs/src/png/zlib/msdos/Makefile.tc b/xs/src/png/zlib/msdos/Makefile.tc
new file mode 100644
index 000000000..5aec82a9d
--- /dev/null
+++ b/xs/src/png/zlib/msdos/Makefile.tc
@@ -0,0 +1,100 @@
+# Makefile for zlib
+# Turbo C 2.01, Turbo C++ 1.01
+# Last updated: 15-Mar-2003
+
+# To use, do "make -fmakefile.tc"
+# To compile in small model, set below: MODEL=s
+
+# WARNING: the small model is supported but only for small values of
+# MAX_WBITS and MAX_MEM_LEVEL. For example:
+#    -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3
+# If you wish to reduce the memory requirements (default 256K for big
+# objects plus a few K), you can add to CFLAGS below:
+#   -DMAX_MEM_LEVEL=7 -DMAX_WBITS=14
+# See zconf.h for details about the memory requirements.
+
+# ------------ Turbo C 2.01, Turbo C++ 1.01 ------------
+MODEL=l
+CC=tcc
+LD=tcc
+AR=tlib
+# CFLAGS=-O2 -G -Z -m$(MODEL) -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3
+CFLAGS=-O2 -G -Z -m$(MODEL)
+LDFLAGS=-m$(MODEL) -f-
+
+
+# variables
+ZLIB_LIB = zlib_$(MODEL).lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+clean:
+	-del *.obj
+	-del *.lib
+	-del *.exe
+	-del zlib_*.bak
+	-del foo.gz
diff --git a/xs/src/png/zlib/nintendods/Makefile b/xs/src/png/zlib/nintendods/Makefile
new file mode 100644
index 000000000..21337d01a
--- /dev/null
+++ b/xs/src/png/zlib/nintendods/Makefile
@@ -0,0 +1,126 @@
+#---------------------------------------------------------------------------------
+.SUFFIXES:
+#---------------------------------------------------------------------------------
+
+ifeq ($(strip $(DEVKITARM)),)
+$(error "Please set DEVKITARM in your environment. export DEVKITARM=<path to>devkitARM")
+endif
+
+include $(DEVKITARM)/ds_rules
+
+#---------------------------------------------------------------------------------
+# TARGET is the name of the output
+# BUILD is the directory where object files & intermediate files will be placed
+# SOURCES is a list of directories containing source code
+# DATA is a list of directories containing data files
+# INCLUDES is a list of directories containing header files
+#---------------------------------------------------------------------------------
+TARGET		:=	$(shell basename $(CURDIR))
+BUILD		:=	build
+SOURCES		:=	../../
+DATA		:=	data
+INCLUDES	:=	include
+
+#---------------------------------------------------------------------------------
+# options for code generation
+#---------------------------------------------------------------------------------
+ARCH	:=	-mthumb -mthumb-interwork
+
+CFLAGS	:=	-Wall -O2\
+		-march=armv5te -mtune=arm946e-s \
+		-fomit-frame-pointer -ffast-math \
+		$(ARCH)
+
+CFLAGS	+=	$(INCLUDE) -DARM9
+CXXFLAGS	:= $(CFLAGS) -fno-rtti -fno-exceptions
+
+ASFLAGS	:=	$(ARCH) -march=armv5te -mtune=arm946e-s
+LDFLAGS	=	-specs=ds_arm9.specs -g $(ARCH) -Wl,-Map,$(notdir $*.map)
+
+#---------------------------------------------------------------------------------
+# list of directories containing libraries, this must be the top level containing
+# include and lib
+#---------------------------------------------------------------------------------
+LIBDIRS	:=	$(LIBNDS)
+
+#---------------------------------------------------------------------------------
+# no real need to edit anything past this point unless you need to add additional
+# rules for different file extensions
+#---------------------------------------------------------------------------------
+ifneq ($(BUILD),$(notdir $(CURDIR)))
+#---------------------------------------------------------------------------------
+
+export OUTPUT	:=	$(CURDIR)/lib/libz.a
+
+export VPATH	:=	$(foreach dir,$(SOURCES),$(CURDIR)/$(dir)) \
+			$(foreach dir,$(DATA),$(CURDIR)/$(dir))
+
+export DEPSDIR	:=	$(CURDIR)/$(BUILD)
+
+CFILES		:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.c)))
+CPPFILES	:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.cpp)))
+SFILES		:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.s)))
+BINFILES	:=	$(foreach dir,$(DATA),$(notdir $(wildcard $(dir)/*.*)))
+
+#---------------------------------------------------------------------------------
+# use CXX for linking C++ projects, CC for standard C
+#---------------------------------------------------------------------------------
+ifeq ($(strip $(CPPFILES)),)
+#---------------------------------------------------------------------------------
+	export LD	:=	$(CC)
+#---------------------------------------------------------------------------------
+else
+#---------------------------------------------------------------------------------
+	export LD	:=	$(CXX)
+#---------------------------------------------------------------------------------
+endif
+#---------------------------------------------------------------------------------
+
+export OFILES	:=	$(addsuffix .o,$(BINFILES)) \
+			$(CPPFILES:.cpp=.o) $(CFILES:.c=.o) $(SFILES:.s=.o)
+
+export INCLUDE	:=	$(foreach dir,$(INCLUDES),-I$(CURDIR)/$(dir)) \
+			$(foreach dir,$(LIBDIRS),-I$(dir)/include) \
+			-I$(CURDIR)/$(BUILD)
+
+.PHONY: $(BUILD) clean all
+
+#---------------------------------------------------------------------------------
+all: $(BUILD)
+	@[ -d $@ ] || mkdir -p include
+	@cp ../../*.h include
+
+lib:
+	@[ -d $@ ] || mkdir -p $@
+	
+$(BUILD): lib
+	@[ -d $@ ] || mkdir -p $@
+	@$(MAKE) --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile
+
+#---------------------------------------------------------------------------------
+clean:
+	@echo clean ...
+	@rm -fr $(BUILD) lib
+
+#---------------------------------------------------------------------------------
+else
+
+DEPENDS	:=	$(OFILES:.o=.d)
+
+#---------------------------------------------------------------------------------
+# main targets
+#---------------------------------------------------------------------------------
+$(OUTPUT)	:	$(OFILES)
+
+#---------------------------------------------------------------------------------
+%.bin.o	:	%.bin
+#---------------------------------------------------------------------------------
+	@echo $(notdir $<)
+	@$(bin2o)
+
+
+-include $(DEPENDS)
+
+#---------------------------------------------------------------------------------------
+endif
+#---------------------------------------------------------------------------------------
diff --git a/xs/src/png/zlib/nintendods/README b/xs/src/png/zlib/nintendods/README
new file mode 100644
index 000000000..ba7a37dbe
--- /dev/null
+++ b/xs/src/png/zlib/nintendods/README
@@ -0,0 +1,5 @@
+This Makefile requires devkitARM (http://www.devkitpro.org/category/devkitarm/) and works inside "contrib/nds". It is based on a devkitARM template.
+
+Eduardo Costa <eduardo.m.costa@gmail.com>
+January 3, 2009
+
diff --git a/xs/src/png/zlib/old/Makefile.emx b/xs/src/png/zlib/old/Makefile.emx
new file mode 100644
index 000000000..612b03791
--- /dev/null
+++ b/xs/src/png/zlib/old/Makefile.emx
@@ -0,0 +1,69 @@
+# Makefile for zlib.  Modified for emx/rsxnt by Chr. Spieler, 6/16/98.
+# Copyright (C) 1995-1998 Jean-loup Gailly.
+# For conditions of distribution and use, see copyright notice in zlib.h
+
+# To compile, or to compile and test, type:
+#
+#   make -fmakefile.emx;  make test -fmakefile.emx
+#
+
+CC=gcc -Zwin32
+
+#CFLAGS=-MMD -O
+#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
+#CFLAGS=-MMD -g -DZLIB_DEBUG
+CFLAGS=-MMD -O3 $(BUTT) -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
+             -Wstrict-prototypes -Wmissing-prototypes
+
+# If cp.exe is available, replace "copy /Y" with "cp -fp" .
+CP=copy /Y
+# If gnu install.exe is available, replace $(CP) with ginstall.
+INSTALL=$(CP)
+# The default value of RM is "rm -f."  If "rm.exe" is found, comment out:
+RM=del
+LDLIBS=-L. -lzlib
+LD=$(CC) -s -o
+LDSHARED=$(CC)
+
+INCL=zlib.h zconf.h
+LIBS=zlib.a
+
+AR=ar rcs
+
+prefix=/usr/local
+exec_prefix = $(prefix)
+
+OBJS = adler32.o compress.o crc32.o deflate.o gzclose.o gzlib.o gzread.o \
+       gzwrite.o infback.o inffast.o inflate.o inftrees.o trees.o uncompr.o zutil.o
+
+TEST_OBJS = example.o minigzip.o
+
+all: example.exe minigzip.exe
+
+test: all
+	./example
+	echo hello world | .\minigzip | .\minigzip -d
+
+%.o : %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+zlib.a: $(OBJS)
+	$(AR) $@ $(OBJS)
+
+%.exe : %.o $(LIBS)
+	$(LD) $@ $< $(LDLIBS)
+
+
+.PHONY : clean
+
+clean:
+	$(RM) *.d
+	$(RM) *.o
+	$(RM) *.exe
+	$(RM) zlib.a
+	$(RM) foo.gz
+
+DEPS := $(wildcard *.d)
+ifneq ($(DEPS),)
+include $(DEPS)
+endif
diff --git a/xs/src/png/zlib/old/Makefile.riscos b/xs/src/png/zlib/old/Makefile.riscos
new file mode 100644
index 000000000..57e29d3fb
--- /dev/null
+++ b/xs/src/png/zlib/old/Makefile.riscos
@@ -0,0 +1,151 @@
+# Project:   zlib_1_03
+# Patched for zlib 1.1.2 rw@shadow.org.uk 19980430
+# test works out-of-the-box, installs `somewhere' on demand
+
+# Toolflags:
+CCflags = -c -depend !Depend -IC: -g -throwback  -DRISCOS  -fah
+C++flags = -c -depend !Depend -IC: -throwback
+Linkflags = -aif -c++ -o $@
+ObjAsmflags = -throwback -NoCache -depend !Depend
+CMHGflags =
+LibFileflags = -c -l -o $@
+Squeezeflags = -o $@
+
+# change the line below to where _you_ want the library installed.
+libdest = lib:zlib
+
+# Final targets:
+@.lib:   @.o.adler32 @.o.compress @.o.crc32 @.o.deflate @.o.gzio \
+        @.o.infblock @.o.infcodes @.o.inffast @.o.inflate @.o.inftrees @.o.infutil @.o.trees \
+        @.o.uncompr @.o.zutil
+        LibFile $(LibFileflags) @.o.adler32 @.o.compress @.o.crc32 @.o.deflate \
+        @.o.gzio @.o.infblock @.o.infcodes @.o.inffast @.o.inflate @.o.inftrees @.o.infutil \
+        @.o.trees @.o.uncompr @.o.zutil
+test:   @.minigzip @.example @.lib
+	@copy @.lib @.libc  A~C~DF~L~N~P~Q~RS~TV
+	@echo running tests: hang on.
+	@/@.minigzip -f -9 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -f -1 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -h -9 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -h -1 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -9 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -1 libc
+	@/@.minigzip -d libc-gz
+	@diff @.lib @.libc
+	@echo that should have reported '@.lib and @.libc identical' if you have diff.
+	@/@.example @.fred @.fred
+	@echo that will have given lots of hello!'s.
+
+@.minigzip:   @.o.minigzip @.lib C:o.Stubs
+        Link $(Linkflags) @.o.minigzip @.lib C:o.Stubs
+@.example:   @.o.example @.lib C:o.Stubs
+        Link $(Linkflags) @.o.example @.lib C:o.Stubs
+
+install: @.lib
+	cdir $(libdest)
+	cdir $(libdest).h
+	@copy @.h.zlib $(libdest).h.zlib A~C~DF~L~N~P~Q~RS~TV
+	@copy @.h.zconf $(libdest).h.zconf A~C~DF~L~N~P~Q~RS~TV
+	@copy @.lib $(libdest).lib  A~C~DF~L~N~P~Q~RS~TV
+	@echo okay, installed zlib in $(libdest)
+
+clean:; remove @.minigzip
+	remove @.example
+	remove @.libc
+	-wipe @.o.* F~r~cV
+	remove @.fred
+
+# User-editable dependencies:
+.c.o:
+        cc $(ccflags) -o $@ $<
+
+# Static dependencies:
+
+# Dynamic dependencies:
+o.example:	c.example
+o.example:	h.zlib
+o.example:	h.zconf
+o.minigzip:	c.minigzip
+o.minigzip:	h.zlib
+o.minigzip:	h.zconf
+o.adler32:	c.adler32
+o.adler32:	h.zlib
+o.adler32:	h.zconf
+o.compress:	c.compress
+o.compress:	h.zlib
+o.compress:	h.zconf
+o.crc32:	c.crc32
+o.crc32:	h.zlib
+o.crc32:	h.zconf
+o.deflate:	c.deflate
+o.deflate:	h.deflate
+o.deflate:	h.zutil
+o.deflate:	h.zlib
+o.deflate:	h.zconf
+o.gzio:	c.gzio
+o.gzio:	h.zutil
+o.gzio:	h.zlib
+o.gzio:	h.zconf
+o.infblock:	c.infblock
+o.infblock:	h.zutil
+o.infblock:	h.zlib
+o.infblock:	h.zconf
+o.infblock:	h.infblock
+o.infblock:	h.inftrees
+o.infblock:	h.infcodes
+o.infblock:	h.infutil
+o.infcodes:	c.infcodes
+o.infcodes:	h.zutil
+o.infcodes:	h.zlib
+o.infcodes:	h.zconf
+o.infcodes:	h.inftrees
+o.infcodes:	h.infblock
+o.infcodes:	h.infcodes
+o.infcodes:	h.infutil
+o.infcodes:	h.inffast
+o.inffast:	c.inffast
+o.inffast:	h.zutil
+o.inffast:	h.zlib
+o.inffast:	h.zconf
+o.inffast:	h.inftrees
+o.inffast:	h.infblock
+o.inffast:	h.infcodes
+o.inffast:	h.infutil
+o.inffast:	h.inffast
+o.inflate:	c.inflate
+o.inflate:	h.zutil
+o.inflate:	h.zlib
+o.inflate:	h.zconf
+o.inflate:	h.infblock
+o.inftrees:	c.inftrees
+o.inftrees:	h.zutil
+o.inftrees:	h.zlib
+o.inftrees:	h.zconf
+o.inftrees:	h.inftrees
+o.inftrees:	h.inffixed
+o.infutil:	c.infutil
+o.infutil:	h.zutil
+o.infutil:	h.zlib
+o.infutil:	h.zconf
+o.infutil:	h.infblock
+o.infutil:	h.inftrees
+o.infutil:	h.infcodes
+o.infutil:	h.infutil
+o.trees:	c.trees
+o.trees:	h.deflate
+o.trees:	h.zutil
+o.trees:	h.zlib
+o.trees:	h.zconf
+o.trees:	h.trees
+o.uncompr:	c.uncompr
+o.uncompr:	h.zlib
+o.uncompr:	h.zconf
+o.zutil:	c.zutil
+o.zutil:	h.zutil
+o.zutil:	h.zlib
+o.zutil:	h.zconf
diff --git a/xs/src/png/zlib/old/README b/xs/src/png/zlib/old/README
new file mode 100644
index 000000000..800bf0798
--- /dev/null
+++ b/xs/src/png/zlib/old/README
@@ -0,0 +1,3 @@
+This directory contains files that have not been updated for zlib 1.2.x
+
+(Volunteers are encouraged to help clean this up.  Thanks.)
diff --git a/xs/src/png/zlib/old/descrip.mms b/xs/src/png/zlib/old/descrip.mms
new file mode 100644
index 000000000..7066da5b5
--- /dev/null
+++ b/xs/src/png/zlib/old/descrip.mms
@@ -0,0 +1,48 @@
+# descrip.mms: MMS description file for building zlib on VMS
+# written by Martin P.J. Zinser <m.zinser@gsi.de>
+
+cc_defs =
+c_deb =
+
+.ifdef __DECC__
+pref = /prefix=all
+.endif
+
+OBJS = adler32.obj, compress.obj, crc32.obj, gzio.obj, uncompr.obj,\
+       deflate.obj, trees.obj, zutil.obj, inflate.obj, infblock.obj,\
+       inftrees.obj, infcodes.obj, infutil.obj, inffast.obj
+
+CFLAGS= $(C_DEB) $(CC_DEFS) $(PREF)
+
+all : example.exe minigzip.exe
+        @ write sys$output " Example applications available"
+libz.olb : libz.olb($(OBJS))
+	@ write sys$output " libz available"
+
+example.exe : example.obj libz.olb
+              link example,libz.olb/lib
+
+minigzip.exe : minigzip.obj libz.olb
+              link minigzip,libz.olb/lib,x11vms:xvmsutils.olb/lib
+
+clean :
+	delete *.obj;*,libz.olb;*
+
+
+# Other dependencies.
+adler32.obj : zutil.h zlib.h zconf.h
+compress.obj : zlib.h zconf.h
+crc32.obj : zutil.h zlib.h zconf.h
+deflate.obj : deflate.h zutil.h zlib.h zconf.h
+example.obj : zlib.h zconf.h
+gzio.obj : zutil.h zlib.h zconf.h
+infblock.obj : zutil.h zlib.h zconf.h infblock.h inftrees.h infcodes.h infutil.h
+infcodes.obj : zutil.h zlib.h zconf.h inftrees.h infutil.h infcodes.h inffast.h
+inffast.obj : zutil.h zlib.h zconf.h inftrees.h infutil.h inffast.h
+inflate.obj : zutil.h zlib.h zconf.h infblock.h
+inftrees.obj : zutil.h zlib.h zconf.h inftrees.h
+infutil.obj : zutil.h zlib.h zconf.h inftrees.h infutil.h
+minigzip.obj : zlib.h zconf.h
+trees.obj : deflate.h zutil.h zlib.h zconf.h
+uncompr.obj : zlib.h zconf.h
+zutil.obj : zutil.h zlib.h zconf.h
diff --git a/xs/src/png/zlib/old/os2/Makefile.os2 b/xs/src/png/zlib/old/os2/Makefile.os2
new file mode 100644
index 000000000..bb426c0d8
--- /dev/null
+++ b/xs/src/png/zlib/old/os2/Makefile.os2
@@ -0,0 +1,136 @@
+# Makefile for zlib under OS/2 using GCC (PGCC)
+# For conditions of distribution and use, see copyright notice in zlib.h
+
+# To compile and test, type:
+#   cp Makefile.os2 ..
+#   cd ..
+#   make -f Makefile.os2 test
+
+# This makefile will build a static library z.lib, a shared library
+# z.dll and a import library zdll.lib. You can use either z.lib or
+# zdll.lib by specifying either -lz or -lzdll on gcc's command line
+
+CC=gcc -Zomf -s
+
+CFLAGS=-O6 -Wall
+#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
+#CFLAGS=-g -DZLIB_DEBUG
+#CFLAGS=-O3 -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
+#           -Wstrict-prototypes -Wmissing-prototypes
+
+#################### BUG WARNING: #####################
+## infcodes.c hits a bug in pgcc-1.0, so you have to use either
+## -O# where # <= 4 or one of (-fno-ommit-frame-pointer or -fno-force-mem)
+## This bug is reportedly fixed in pgcc >1.0, but this was not tested
+CFLAGS+=-fno-force-mem
+
+LDFLAGS=-s -L. -lzdll -Zcrtdll
+LDSHARED=$(CC) -s -Zomf -Zdll -Zcrtdll
+
+VER=1.1.0
+ZLIB=z.lib
+SHAREDLIB=z.dll
+SHAREDLIBIMP=zdll.lib
+LIBS=$(ZLIB) $(SHAREDLIB) $(SHAREDLIBIMP)
+
+AR=emxomfar cr
+IMPLIB=emximp
+RANLIB=echo
+TAR=tar
+SHELL=bash
+
+prefix=/usr/local
+exec_prefix = $(prefix)
+
+OBJS = adler32.o compress.o crc32.o gzio.o uncompr.o deflate.o trees.o \
+       zutil.o inflate.o infblock.o inftrees.o infcodes.o infutil.o inffast.o
+
+TEST_OBJS = example.o minigzip.o
+
+DISTFILES = README INDEX ChangeLog configure Make*[a-z0-9] *.[ch] descrip.mms \
+  algorithm.txt zlib.3 msdos/Make*[a-z0-9] msdos/zlib.def msdos/zlib.rc \
+  nt/Makefile.nt nt/zlib.dnt  contrib/README.contrib contrib/*.txt \
+  contrib/asm386/*.asm contrib/asm386/*.c \
+  contrib/asm386/*.bat contrib/asm386/zlibvc.d?? contrib/iostream/*.cpp \
+  contrib/iostream/*.h  contrib/iostream2/*.h contrib/iostream2/*.cpp \
+  contrib/untgz/Makefile contrib/untgz/*.c contrib/untgz/*.w32
+
+all: example.exe minigzip.exe
+
+test: all
+	@LD_LIBRARY_PATH=.:$(LD_LIBRARY_PATH) ; export LD_LIBRARY_PATH; \
+	echo hello world | ./minigzip | ./minigzip -d || \
+	  echo '		*** minigzip test FAILED ***' ; \
+	if ./example; then \
+	  echo '		*** zlib test OK ***'; \
+	else \
+	  echo '		*** zlib test FAILED ***'; \
+	fi
+
+$(ZLIB): $(OBJS)
+	$(AR) $@ $(OBJS)
+	-@ ($(RANLIB) $@ || true) >/dev/null 2>&1
+
+$(SHAREDLIB): $(OBJS) os2/z.def
+	$(LDSHARED) -o $@ $^
+
+$(SHAREDLIBIMP): os2/z.def
+	$(IMPLIB) -o $@ $^
+
+example.exe: example.o $(LIBS)
+	$(CC) $(CFLAGS) -o $@ example.o $(LDFLAGS)
+
+minigzip.exe: minigzip.o $(LIBS)
+	$(CC) $(CFLAGS) -o $@ minigzip.o $(LDFLAGS)
+
+clean:
+	rm -f *.o *~ example minigzip libz.a libz.so* foo.gz
+
+distclean:	clean
+
+zip:
+	mv Makefile Makefile~; cp -p Makefile.in Makefile
+	rm -f test.c ztest*.c
+	v=`sed -n -e 's/\.//g' -e '/VERSION "/s/.*"\(.*\)".*/\1/p' < zlib.h`;\
+	zip -ul9 zlib$$v $(DISTFILES)
+	mv Makefile~ Makefile
+
+dist:
+	mv Makefile Makefile~; cp -p Makefile.in Makefile
+	rm -f test.c ztest*.c
+	d=zlib-`sed -n '/VERSION "/s/.*"\(.*\)".*/\1/p' < zlib.h`;\
+	rm -f $$d.tar.gz; \
+	if test ! -d ../$$d; then rm -f ../$$d; ln -s `pwd` ../$$d; fi; \
+	files=""; \
+	for f in $(DISTFILES); do files="$$files $$d/$$f"; done; \
+	cd ..; \
+	GZIP=-9 $(TAR) chofz $$d/$$d.tar.gz $$files; \
+	if test ! -d $$d; then rm -f $$d; fi
+	mv Makefile~ Makefile
+
+tags:
+	etags *.[ch]
+
+depend:
+	makedepend -- $(CFLAGS) -- *.[ch]
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+adler32.o: zlib.h zconf.h
+compress.o: zlib.h zconf.h
+crc32.o: zlib.h zconf.h
+deflate.o: deflate.h zutil.h zlib.h zconf.h
+example.o: zlib.h zconf.h
+gzio.o: zutil.h zlib.h zconf.h
+infblock.o: infblock.h inftrees.h infcodes.h infutil.h zutil.h zlib.h zconf.h
+infcodes.o: zutil.h zlib.h zconf.h
+infcodes.o: inftrees.h infblock.h infcodes.h infutil.h inffast.h
+inffast.o: zutil.h zlib.h zconf.h inftrees.h
+inffast.o: infblock.h infcodes.h infutil.h inffast.h
+inflate.o: zutil.h zlib.h zconf.h infblock.h
+inftrees.o: zutil.h zlib.h zconf.h inftrees.h
+infutil.o: zutil.h zlib.h zconf.h infblock.h inftrees.h infcodes.h infutil.h
+minigzip.o: zlib.h zconf.h
+trees.o: deflate.h zutil.h zlib.h zconf.h trees.h
+uncompr.o: zlib.h zconf.h
+zutil.o: zutil.h zlib.h zconf.h
diff --git a/xs/src/png/zlib/old/os2/zlib.def b/xs/src/png/zlib/old/os2/zlib.def
new file mode 100644
index 000000000..4c753f1a3
--- /dev/null
+++ b/xs/src/png/zlib/old/os2/zlib.def
@@ -0,0 +1,51 @@
+;
+; Slightly modified version of ../nt/zlib.dnt :-)
+;
+
+LIBRARY		Z
+DESCRIPTION	"Zlib compression library for OS/2"
+CODE		PRELOAD MOVEABLE DISCARDABLE
+DATA		PRELOAD MOVEABLE MULTIPLE
+
+EXPORTS
+    adler32
+    compress
+    crc32
+    deflate
+    deflateCopy
+    deflateEnd
+    deflateInit2_
+    deflateInit_
+    deflateParams
+    deflateReset
+    deflateSetDictionary
+    gzclose
+    gzdopen
+    gzerror
+    gzflush
+    gzopen
+    gzread
+    gzwrite
+    inflate
+    inflateEnd
+    inflateInit2_
+    inflateInit_
+    inflateReset
+    inflateSetDictionary
+    inflateSync
+    uncompress
+    zlibVersion
+    gzprintf
+    gzputc
+    gzgetc
+    gzseek
+    gzrewind
+    gztell
+    gzeof
+    gzsetparams
+    zError
+    inflateSyncPoint
+    get_crc_table
+    compress2
+    gzputs
+    gzgets
diff --git a/xs/src/png/zlib/old/visual-basic.txt b/xs/src/png/zlib/old/visual-basic.txt
new file mode 100644
index 000000000..57efe5812
--- /dev/null
+++ b/xs/src/png/zlib/old/visual-basic.txt
@@ -0,0 +1,160 @@
+See below some functions declarations for Visual Basic.
+
+Frequently Asked Question:
+
+Q: Each time I use the compress function I get the -5 error (not enough
+   room in the output buffer).
+
+A: Make sure that the length of the compressed buffer is passed by
+   reference ("as any"), not by value ("as long"). Also check that
+   before the call of compress this length is equal to the total size of
+   the compressed buffer and not zero.
+
+
+From: "Jon Caruana" <jon-net@usa.net>
+Subject: Re: How to port zlib declares to vb?
+Date: Mon, 28 Oct 1996 18:33:03 -0600
+
+Got the answer! (I haven't had time to check this but it's what I got, and
+looks correct):
+
+He has the following routines working:
+        compress
+        uncompress
+        gzopen
+        gzwrite
+        gzread
+        gzclose
+
+Declares follow: (Quoted from Carlos Rios <c_rios@sonda.cl>, in Vb4 form)
+
+#If Win16 Then   'Use Win16 calls.
+Declare Function compress Lib "ZLIB.DLL" (ByVal compr As
+        String, comprLen As Any, ByVal buf As String, ByVal buflen
+        As Long) As Integer
+Declare Function uncompress Lib "ZLIB.DLL" (ByVal uncompr
+        As String, uncomprLen As Any, ByVal compr As String, ByVal
+        lcompr As Long) As Integer
+Declare Function gzopen Lib "ZLIB.DLL" (ByVal filePath As
+        String, ByVal mode As String) As Long
+Declare Function gzread Lib "ZLIB.DLL" (ByVal file As
+        Long, ByVal uncompr As String, ByVal uncomprLen As Integer)
+        As Integer
+Declare Function gzwrite Lib "ZLIB.DLL" (ByVal file As
+        Long, ByVal uncompr As String, ByVal uncomprLen As Integer)
+        As Integer
+Declare Function gzclose Lib "ZLIB.DLL" (ByVal file As
+        Long) As Integer
+#Else
+Declare Function compress Lib "ZLIB32.DLL"
+        (ByVal compr As String, comprLen As Any, ByVal buf As
+        String, ByVal buflen As Long) As Integer
+Declare Function uncompress Lib "ZLIB32.DLL"
+        (ByVal uncompr As String, uncomprLen As Any, ByVal compr As
+        String, ByVal lcompr As Long) As Long
+Declare Function gzopen Lib "ZLIB32.DLL"
+        (ByVal file As String, ByVal mode As String) As Long
+Declare Function gzread Lib "ZLIB32.DLL"
+        (ByVal file As Long, ByVal uncompr As String, ByVal
+        uncomprLen As Long) As Long
+Declare Function gzwrite Lib "ZLIB32.DLL"
+        (ByVal file As Long, ByVal uncompr As String, ByVal
+        uncomprLen As Long) As Long
+Declare Function gzclose Lib "ZLIB32.DLL"
+        (ByVal file As Long) As Long
+#End If
+
+-Jon Caruana
+jon-net@usa.net
+Microsoft Sitebuilder Network Level 1 Member - HTML Writer's Guild Member
+
+
+Here is another example from Michael <michael_borgsys@hotmail.com> that he
+says conforms to the VB guidelines, and that solves the problem of not
+knowing the uncompressed size by storing it at the end of the file:
+
+'Calling the functions:
+'bracket meaning: <parameter> [optional] {Range of possible values}
+'Call subCompressFile(<path with filename to compress> [, <path with
+filename to write to>, [level of compression {1..9}]])
+'Call subUncompressFile(<path with filename to compress>)
+
+Option Explicit
+Private lngpvtPcnSml As Long 'Stores value for 'lngPercentSmaller'
+Private Const SUCCESS As Long = 0
+Private Const strFilExt As String = ".cpr"
+Private Declare Function lngfncCpr Lib "zlib.dll" Alias "compress2" (ByRef
+dest As Any, ByRef destLen As Any, ByRef src As Any, ByVal srcLen As Long,
+ByVal level As Integer) As Long
+Private Declare Function lngfncUcp Lib "zlib.dll" Alias "uncompress" (ByRef
+dest As Any, ByRef destLen As Any, ByRef src As Any, ByVal srcLen As Long)
+As Long
+
+Public Sub subCompressFile(ByVal strargOriFilPth As String, Optional ByVal
+strargCprFilPth As String, Optional ByVal intLvl As Integer = 9)
+    Dim strCprPth As String
+    Dim lngOriSiz As Long
+    Dim lngCprSiz As Long
+    Dim bytaryOri() As Byte
+    Dim bytaryCpr() As Byte
+    lngOriSiz = FileLen(strargOriFilPth)
+    ReDim bytaryOri(lngOriSiz - 1)
+    Open strargOriFilPth For Binary Access Read As #1
+        Get #1, , bytaryOri()
+    Close #1
+    strCprPth = IIf(strargCprFilPth = "", strargOriFilPth, strargCprFilPth)
+'Select file path and name
+    strCprPth = strCprPth & IIf(Right(strCprPth, Len(strFilExt)) =
+strFilExt, "", strFilExt) 'Add file extension if not exists
+    lngCprSiz = (lngOriSiz * 1.01) + 12 'Compression needs temporary a bit
+more space then original file size
+    ReDim bytaryCpr(lngCprSiz - 1)
+    If lngfncCpr(bytaryCpr(0), lngCprSiz, bytaryOri(0), lngOriSiz, intLvl) =
+SUCCESS Then
+        lngpvtPcnSml = (1# - (lngCprSiz / lngOriSiz)) * 100
+        ReDim Preserve bytaryCpr(lngCprSiz - 1)
+        Open strCprPth For Binary Access Write As #1
+            Put #1, , bytaryCpr()
+            Put #1, , lngOriSiz 'Add the the original size value to the end
+(last 4 bytes)
+        Close #1
+    Else
+        MsgBox "Compression error"
+    End If
+    Erase bytaryCpr
+    Erase bytaryOri
+End Sub
+
+Public Sub subUncompressFile(ByVal strargFilPth As String)
+    Dim bytaryCpr() As Byte
+    Dim bytaryOri() As Byte
+    Dim lngOriSiz As Long
+    Dim lngCprSiz As Long
+    Dim strOriPth As String
+    lngCprSiz = FileLen(strargFilPth)
+    ReDim bytaryCpr(lngCprSiz - 1)
+    Open strargFilPth For Binary Access Read As #1
+        Get #1, , bytaryCpr()
+    Close #1
+    'Read the original file size value:
+    lngOriSiz = bytaryCpr(lngCprSiz - 1) * (2 ^ 24) _
+              + bytaryCpr(lngCprSiz - 2) * (2 ^ 16) _
+              + bytaryCpr(lngCprSiz - 3) * (2 ^ 8) _
+              + bytaryCpr(lngCprSiz - 4)
+    ReDim Preserve bytaryCpr(lngCprSiz - 5) 'Cut of the original size value
+    ReDim bytaryOri(lngOriSiz - 1)
+    If lngfncUcp(bytaryOri(0), lngOriSiz, bytaryCpr(0), lngCprSiz) = SUCCESS
+Then
+        strOriPth = Left(strargFilPth, Len(strargFilPth) - Len(strFilExt))
+        Open strOriPth For Binary Access Write As #1
+            Put #1, , bytaryOri()
+        Close #1
+    Else
+        MsgBox "Uncompression error"
+    End If
+    Erase bytaryCpr
+    Erase bytaryOri
+End Sub
+Public Property Get lngPercentSmaller() As Long
+    lngPercentSmaller = lngpvtPcnSml
+End Property
diff --git a/xs/src/png/zlib/os400/README400 b/xs/src/png/zlib/os400/README400
new file mode 100644
index 000000000..4f98334f5
--- /dev/null
+++ b/xs/src/png/zlib/os400/README400
@@ -0,0 +1,48 @@
+        ZLIB version 1.2.11 for OS/400 installation instructions
+
+1) Download and unpack the zlib tarball to some IFS directory.
+   (i.e.: /path/to/the/zlib/ifs/source/directory)
+
+   If the installed IFS command suppors gzip format, this is straightforward,
+else you have to unpack first to some directory on a system supporting it,
+then move the whole directory to the IFS via the network (via SMB or FTP).
+
+2) Edit the configuration parameters in the compilation script.
+
+        EDTF STMF('/path/to/the/zlib/ifs/source/directory/os400/make.sh')
+
+Tune the parameters according to your needs if not matching the defaults.
+Save the file and exit after edition.
+
+3) Enter qshell, then work in the zlib OS/400 specific directory.
+
+        QSH
+        cd /path/to/the/zlib/ifs/source/directory/os400
+
+4) Compile and install
+
+        sh make.sh
+
+The script will:
+- create the libraries, objects and IFS directories for the zlib environment,
+- compile all modules,
+- create a service program,
+- create a static and a dynamic binding directory,
+- install header files for C/C++ and for ILE/RPG, both for compilation in
+  DB2 and IFS environments.
+
+That's all. 
+
+
+Notes:  For OS/400 ILE RPG programmers, a /copy member defining the ZLIB
+                API prototypes for ILE RPG can be found in ZLIB/H(ZLIB.INC).
+                In the ILE environment, the same definitions are available from
+                file zlib.inc located in the same IFS include directory as the
+                C/C++ header files.
+                Please read comments in this member for more information.
+
+        Remember that most foreign textual data are ASCII coded: this
+                implementation does not handle conversion from/to ASCII, so
+                text data code conversions must be done explicitely.
+
+        Mainly for the reason above, always open zipped files in binary mode.
diff --git a/xs/src/png/zlib/os400/bndsrc b/xs/src/png/zlib/os400/bndsrc
new file mode 100644
index 000000000..5e6e0a2f0
--- /dev/null
+++ b/xs/src/png/zlib/os400/bndsrc
@@ -0,0 +1,119 @@
+STRPGMEXP PGMLVL(*CURRENT) SIGNATURE('ZLIB')
+
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+/*   Version 1.1.3 entry points.                                    */
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+
+  EXPORT SYMBOL("adler32")
+  EXPORT SYMBOL("compress")
+  EXPORT SYMBOL("compress2")
+  EXPORT SYMBOL("crc32")
+  EXPORT SYMBOL("get_crc_table")
+  EXPORT SYMBOL("deflate")
+  EXPORT SYMBOL("deflateEnd")
+  EXPORT SYMBOL("deflateSetDictionary")
+  EXPORT SYMBOL("deflateCopy")
+  EXPORT SYMBOL("deflateReset")
+  EXPORT SYMBOL("deflateParams")
+  EXPORT SYMBOL("deflatePrime")
+  EXPORT SYMBOL("deflateInit_")
+  EXPORT SYMBOL("deflateInit2_")
+  EXPORT SYMBOL("gzopen")
+  EXPORT SYMBOL("gzdopen")
+  EXPORT SYMBOL("gzsetparams")
+  EXPORT SYMBOL("gzread")
+  EXPORT SYMBOL("gzwrite")
+  EXPORT SYMBOL("gzprintf")
+  EXPORT SYMBOL("gzputs")
+  EXPORT SYMBOL("gzgets")
+  EXPORT SYMBOL("gzputc")
+  EXPORT SYMBOL("gzgetc")
+  EXPORT SYMBOL("gzflush")
+  EXPORT SYMBOL("gzseek")
+  EXPORT SYMBOL("gzrewind")
+  EXPORT SYMBOL("gztell")
+  EXPORT SYMBOL("gzeof")
+  EXPORT SYMBOL("gzclose")
+  EXPORT SYMBOL("gzerror")
+  EXPORT SYMBOL("inflate")
+  EXPORT SYMBOL("inflateEnd")
+  EXPORT SYMBOL("inflateSetDictionary")
+  EXPORT SYMBOL("inflateSync")
+  EXPORT SYMBOL("inflateReset")
+  EXPORT SYMBOL("inflateInit_")
+  EXPORT SYMBOL("inflateInit2_")
+  EXPORT SYMBOL("inflateSyncPoint")
+  EXPORT SYMBOL("uncompress")
+  EXPORT SYMBOL("zlibVersion")
+  EXPORT SYMBOL("zError")
+  EXPORT SYMBOL("z_errmsg")
+
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+/*   Version 1.2.1 additional entry points.                         */
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+
+  EXPORT SYMBOL("compressBound")
+  EXPORT SYMBOL("deflateBound")
+  EXPORT SYMBOL("deflatePending")
+  EXPORT SYMBOL("gzungetc")
+  EXPORT SYMBOL("gzclearerr")
+  EXPORT SYMBOL("inflateBack")
+  EXPORT SYMBOL("inflateBackEnd")
+  EXPORT SYMBOL("inflateBackInit_")
+  EXPORT SYMBOL("inflateCopy")
+  EXPORT SYMBOL("zlibCompileFlags")
+
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+/*   Version 1.2.4 additional entry points.                         */
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+
+  EXPORT SYMBOL("adler32_combine")
+  EXPORT SYMBOL("adler32_combine64")
+  EXPORT SYMBOL("crc32_combine")
+  EXPORT SYMBOL("crc32_combine64")
+  EXPORT SYMBOL("deflateSetHeader")
+  EXPORT SYMBOL("deflateTune")
+  EXPORT SYMBOL("gzbuffer")
+  EXPORT SYMBOL("gzclose_r")
+  EXPORT SYMBOL("gzclose_w")
+  EXPORT SYMBOL("gzdirect")
+  EXPORT SYMBOL("gzoffset")
+  EXPORT SYMBOL("gzoffset64")
+  EXPORT SYMBOL("gzopen64")
+  EXPORT SYMBOL("gzseek64")
+  EXPORT SYMBOL("gztell64")
+  EXPORT SYMBOL("inflateGetHeader")
+  EXPORT SYMBOL("inflateMark")
+  EXPORT SYMBOL("inflatePrime")
+  EXPORT SYMBOL("inflateReset2")
+  EXPORT SYMBOL("inflateUndermine")
+
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+/*   Version 1.2.6 additional entry points.                         */
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+
+  EXPORT SYMBOL("deflateResetKeep")
+  EXPORT SYMBOL("gzgetc_")
+  EXPORT SYMBOL("inflateResetKeep")
+
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+/*   Version 1.2.8 additional entry points.                         */
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+
+  EXPORT SYMBOL("gzvprintf")
+  EXPORT SYMBOL("inflateGetDictionary")
+
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+/*   Version 1.2.9 additional entry points.                         */
+/*@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@*/
+
+  EXPORT SYMBOL("adler32_z")
+  EXPORT SYMBOL("crc32_z")
+  EXPORT SYMBOL("deflateGetDictionary")
+  EXPORT SYMBOL("gzfread")
+  EXPORT SYMBOL("gzfwrite")
+  EXPORT SYMBOL("inflateCodesUsed")
+  EXPORT SYMBOL("inflateValidate")
+  EXPORT SYMBOL("uncompress2")
+
+ENDPGMEXP
diff --git a/xs/src/png/zlib/os400/make.sh b/xs/src/png/zlib/os400/make.sh
new file mode 100644
index 000000000..19eec117a
--- /dev/null
+++ b/xs/src/png/zlib/os400/make.sh
@@ -0,0 +1,366 @@
+#!/bin/sh
+#
+#       ZLIB compilation script for the OS/400.
+#
+#
+#       This is a shell script since make is not a standard component of OS/400.
+
+
+################################################################################
+#
+#                       Tunable configuration parameters.
+#
+################################################################################
+
+TARGETLIB='ZLIB'                # Target OS/400 program library
+STATBNDDIR='ZLIB_A'             # Static binding directory.
+DYNBNDDIR='ZLIB'                # Dynamic binding directory.
+SRVPGM="ZLIB"                   # Service program.
+IFSDIR='/zlib'                  # IFS support base directory.
+TGTCCSID='500'                  # Target CCSID of objects
+DEBUG='*NONE'                   # Debug level
+OPTIMIZE='40'                   # Optimisation level
+OUTPUT='*NONE'                  # Compilation output option.
+TGTRLS='V6R1M0'                 # Target OS release
+
+export TARGETLIB STATBNDDIR DYNBNDDIR SRVPGM IFSDIR
+export TGTCCSID DEBUG OPTIMIZE OUTPUT TGTRLS
+
+
+################################################################################
+#
+#                       OS/400 specific definitions.
+#
+################################################################################
+
+LIBIFSNAME="/QSYS.LIB/${TARGETLIB}.LIB"
+
+
+################################################################################
+#
+#                               Procedures.
+#
+################################################################################
+
+#       action_needed dest [src]
+#
+#       dest is an object to build
+#       if specified, src is an object on which dest depends.
+#
+#       exit 0 (succeeds) if some action has to be taken, else 1.
+
+action_needed()
+
+{
+        [ ! -e "${1}" ] && return 0
+        [ "${2}" ] || return 1
+        [ "${1}" -ot "${2}" ] && return 0
+        return 1
+}
+
+
+#       make_module module_name source_name [additional_definitions]
+#
+#       Compile source name into module if needed.
+#       As side effect, append the module name to variable MODULES.
+#       Set LINK to "YES" if the module has been compiled.
+
+make_module()
+
+{
+    MODULES="${MODULES} ${1}"
+    MODIFSNAME="${LIBIFSNAME}/${1}.MODULE"
+    CSRC="`basename \"${2}\"`"
+
+    if action_needed "${MODIFSNAME}" "${2}"
+    then    :
+    elif [ ! "`sed -e \"/<source name=\\\"${CSRC}\\\">/,/<\\\\/source>/!d\" \
+      -e '/<depend /!d'                                                 \
+      -e 's/.* name=\"\\([^\"]*\\)\".*/\\1/' < \"${TOPDIR}/treebuild.xml\" |
+        while read HDR
+        do      if action_needed \"${MODIFSNAME}\" \"${IFSDIR}/include/${HDR}\"
+                then    echo recompile
+                        break
+                fi
+        done`" ]
+    then    return 0
+    fi
+
+    CMD="CRTCMOD MODULE(${TARGETLIB}/${1}) SRCSTMF('${2}')"
+    CMD="${CMD} SYSIFCOPT(*IFS64IO) OPTION(*INCDIRFIRST)"
+    CMD="${CMD} LOCALETYPE(*LOCALE) FLAG(10)"
+    CMD="${CMD} INCDIR('${IFSDIR}/include' ${INCLUDES})"
+    CMD="${CMD} TGTCCSID(${TGTCCSID}) TGTRLS(${TGTRLS})"
+    CMD="${CMD} OUTPUT(${OUTPUT})"
+    CMD="${CMD} OPTIMIZE(${OPTIMIZE})"
+    CMD="${CMD} DBGVIEW(${DEBUG})"
+    system "${CMD}"
+    LINK=YES
+}
+
+
+#       Determine DB2 object name from IFS name.
+
+db2_name()
+
+{
+        basename "${1}"                                                 |
+        tr 'a-z-' 'A-Z_'                                                |
+        sed -e 's/\..*//'                                               \
+            -e 's/^\(.\).*\(.........\)$/\1\2/'
+}
+
+
+#       Force enumeration types to be the same size as integers.
+
+copy_hfile()
+
+{
+        sed -e '1i\
+#pragma enum(int)\
+' "${@}" -e '$a\
+#pragma enum(pop)\
+'
+}
+
+
+################################################################################
+#
+#                             Script initialization.
+#
+################################################################################
+
+SCRIPTDIR=`dirname "${0}"`
+
+case "${SCRIPTDIR}" in
+/*)     ;;
+*)      SCRIPTDIR="`pwd`/${SCRIPTDIR}"
+esac
+
+while true
+do      case "${SCRIPTDIR}" in
+        */.)    SCRIPTDIR="${SCRIPTDIR%/.}";;
+        *)      break;;
+        esac
+done
+
+#  The script directory is supposed to be in ${TOPDIR}/os400.
+
+TOPDIR=`dirname "${SCRIPTDIR}"`
+export SCRIPTDIR TOPDIR
+cd "${TOPDIR}"
+
+
+#  Extract the version from the master compilation XML file.
+
+VERSION=`sed -e '/^<package /!d'                                        \
+            -e 's/^.* version="\([0-9.]*\)".*$/\1/' -e 'q'              \
+            < treebuild.xml`
+export VERSION
+
+################################################################################
+
+
+#       Create the OS/400 library if it does not exist.
+
+if action_needed "${LIBIFSNAME}"
+then    CMD="CRTLIB LIB(${TARGETLIB}) TEXT('ZLIB: Data compression API')"
+        system "${CMD}"
+fi
+
+
+#       Create the DOCS source file if it does not exist.
+
+if action_needed "${LIBIFSNAME}/DOCS.FILE"
+then    CMD="CRTSRCPF FILE(${TARGETLIB}/DOCS) RCDLEN(112)"
+        CMD="${CMD} CCSID(${TGTCCSID}) TEXT('Documentation texts')"
+        system "${CMD}"
+fi
+
+#       Copy some documentation files if needed.
+
+for TEXT in "${TOPDIR}/ChangeLog" "${TOPDIR}/FAQ"                       \
+    "${TOPDIR}/README" "${SCRIPTDIR}/README400"
+do      MEMBER="${LIBIFSNAME}/DOCS.FILE/`db2_name \"${TEXT}\"`.MBR"
+
+        if action_needed "${MEMBER}" "${TEXT}"
+        then    CMD="CPY OBJ('${TEXT}') TOOBJ('${MEMBER}') TOCCSID(${TGTCCSID})"
+                CMD="${CMD} DTAFMT(*TEXT) REPLACE(*YES)"
+                system "${CMD}"
+        fi
+done
+
+
+#       Create the OS/400 source program file for the C header files.
+
+SRCPF="${LIBIFSNAME}/H.FILE"
+
+if action_needed "${SRCPF}"
+then    CMD="CRTSRCPF FILE(${TARGETLIB}/H) RCDLEN(112)"
+        CMD="${CMD} CCSID(${TGTCCSID}) TEXT('ZLIB: C/C++ header files')"
+        system "${CMD}"
+fi
+
+
+#       Create the IFS directory for the C header files.
+
+if action_needed "${IFSDIR}/include"
+then    mkdir -p "${IFSDIR}/include"
+fi
+
+#       Copy the header files to DB2 library. Link from IFS include directory.
+
+for HFILE in "${TOPDIR}/"*.h
+do      DEST="${SRCPF}/`db2_name \"${HFILE}\"`.MBR"
+
+        if action_needed "${DEST}" "${HFILE}"
+        then    copy_hfile < "${HFILE}" > tmphdrfile
+
+                #       Need to translate to target CCSID.
+
+                CMD="CPY OBJ('`pwd`/tmphdrfile') TOOBJ('${DEST}')"
+                CMD="${CMD} TOCCSID(${TGTCCSID}) DTAFMT(*TEXT) REPLACE(*YES)"
+                system "${CMD}"
+                # touch -r "${HFILE}" "${DEST}"
+                rm -f tmphdrfile
+        fi
+
+        IFSFILE="${IFSDIR}/include/`basename \"${HFILE}\"`"
+
+        if action_needed "${IFSFILE}" "${DEST}"
+        then    rm -f "${IFSFILE}"
+                ln -s "${DEST}" "${IFSFILE}"
+        fi
+done
+
+
+#       Install the ILE/RPG header file.
+
+
+HFILE="${SCRIPTDIR}/zlib.inc"
+DEST="${SRCPF}/ZLIB.INC.MBR"
+
+if action_needed "${DEST}" "${HFILE}"
+then    CMD="CPY OBJ('${HFILE}') TOOBJ('${DEST}')"
+        CMD="${CMD} TOCCSID(${TGTCCSID}) DTAFMT(*TEXT) REPLACE(*YES)"
+        system "${CMD}"
+        # touch -r "${HFILE}" "${DEST}"
+fi
+
+IFSFILE="${IFSDIR}/include/`basename \"${HFILE}\"`"
+
+if action_needed "${IFSFILE}" "${DEST}"
+then    rm -f "${IFSFILE}"
+        ln -s "${DEST}" "${IFSFILE}"
+fi
+
+
+#      Create and compile the identification source file.
+
+echo '#pragma comment(user, "ZLIB version '"${VERSION}"'")' > os400.c
+echo '#pragma comment(user, __DATE__)' >> os400.c
+echo '#pragma comment(user, __TIME__)' >> os400.c
+echo '#pragma comment(copyright, "Copyright (C) 1995-2017 Jean-Loup Gailly, Mark Adler. OS/400 version by P. Monnerat.")' >> os400.c
+make_module     OS400           os400.c
+LINK=                           # No need to rebuild service program yet.
+MODULES=
+
+
+#       Get source list.
+
+CSOURCES=`sed -e '/<source name="/!d'                                   \
+    -e 's/.* name="\([^"]*\)".*/\1/' < treebuild.xml`
+
+#       Compile the sources into modules.
+
+for SRC in ${CSOURCES}
+do      MODULE=`db2_name "${SRC}"`
+        make_module "${MODULE}" "${SRC}"
+done
+
+
+#       If needed, (re)create the static binding directory.
+
+if action_needed "${LIBIFSNAME}/${STATBNDDIR}.BNDDIR"
+then    LINK=YES
+fi
+
+if [ "${LINK}" ]
+then    rm -rf "${LIBIFSNAME}/${STATBNDDIR}.BNDDIR"
+        CMD="CRTBNDDIR BNDDIR(${TARGETLIB}/${STATBNDDIR})"
+        CMD="${CMD} TEXT('ZLIB static binding directory')"
+        system "${CMD}"
+
+        for MODULE in ${MODULES}
+        do      CMD="ADDBNDDIRE BNDDIR(${TARGETLIB}/${STATBNDDIR})"
+                CMD="${CMD} OBJ((${TARGETLIB}/${MODULE} *MODULE))"
+                system "${CMD}"
+        done
+fi
+
+
+#       The exportation file for service program creation must be in a DB2
+#               source file, so make sure it exists.
+
+if action_needed "${LIBIFSNAME}/TOOLS.FILE"
+then    CMD="CRTSRCPF FILE(${TARGETLIB}/TOOLS) RCDLEN(112)"
+        CMD="${CMD} CCSID(${TGTCCSID}) TEXT('ZLIB: build tools')"
+        system "${CMD}"
+fi
+
+
+DEST="${LIBIFSNAME}/TOOLS.FILE/BNDSRC.MBR"
+
+if action_needed "${SCRIPTDIR}/bndsrc" "${DEST}"
+then    CMD="CPY OBJ('${SCRIPTDIR}/bndsrc') TOOBJ('${DEST}')"
+        CMD="${CMD} TOCCSID(${TGTCCSID}) DTAFMT(*TEXT) REPLACE(*YES)"
+        system "${CMD}"
+        # touch -r "${SCRIPTDIR}/bndsrc" "${DEST}"
+        LINK=YES
+fi
+
+
+#       Build the service program if needed.
+
+if action_needed "${LIBIFSNAME}/${SRVPGM}.SRVPGM"
+then    LINK=YES
+fi
+
+if [ "${LINK}" ]
+then    CMD="CRTSRVPGM SRVPGM(${TARGETLIB}/${SRVPGM})"
+        CMD="${CMD} SRCFILE(${TARGETLIB}/TOOLS) SRCMBR(BNDSRC)"
+        CMD="${CMD} MODULE(${TARGETLIB}/OS400)"
+        CMD="${CMD} BNDDIR(${TARGETLIB}/${STATBNDDIR})"
+        CMD="${CMD} TEXT('ZLIB ${VERSION} dynamic library')"
+        CMD="${CMD} TGTRLS(${TGTRLS})"
+        system "${CMD}"
+        LINK=YES
+
+        #       Duplicate the service program for a versioned backup.
+
+        BACKUP=`echo "${SRVPGM}${VERSION}"                              |
+                sed -e 's/.*\(..........\)$/\1/' -e 's/\./_/g'`
+        BACKUP="`db2_name \"${BACKUP}\"`"
+        BKUPIFSNAME="${LIBIFSNAME}/${BACKUP}.SRVPGM"
+        rm -f "${BKUPIFSNAME}"
+        CMD="CRTDUPOBJ OBJ(${SRVPGM}) FROMLIB(${TARGETLIB})"
+        CMD="${CMD} OBJTYPE(*SRVPGM) NEWOBJ(${BACKUP})"
+        system "${CMD}"
+fi
+
+
+#       If needed, (re)create the dynamic binding directory.
+
+if action_needed "${LIBIFSNAME}/${DYNBNDDIR}.BNDDIR"
+then    LINK=YES
+fi
+
+if [ "${LINK}" ]
+then    rm -rf "${LIBIFSNAME}/${DYNBNDDIR}.BNDDIR"
+        CMD="CRTBNDDIR BNDDIR(${TARGETLIB}/${DYNBNDDIR})"
+        CMD="${CMD} TEXT('ZLIB dynamic binding directory')"
+        system "${CMD}"
+        CMD="ADDBNDDIRE BNDDIR(${TARGETLIB}/${DYNBNDDIR})"
+        CMD="${CMD} OBJ((*LIBL/${SRVPGM} *SRVPGM))"
+        system "${CMD}"
+fi
diff --git a/xs/src/png/zlib/os400/zlib.inc b/xs/src/png/zlib/os400/zlib.inc
new file mode 100644
index 000000000..c6aca2cbd
--- /dev/null
+++ b/xs/src/png/zlib/os400/zlib.inc
@@ -0,0 +1,527 @@
+      *  ZLIB.INC - Interface to the general purpose compression library
+      *
+      *  ILE RPG400 version by Patrick Monnerat, DATASPHERE.
+      *  Version 1.2.11
+      *
+      *
+      *  WARNING:
+      *     Procedures inflateInit(), inflateInit2(), deflateInit(),
+      *         deflateInit2() and inflateBackInit() need to be called with
+      *         two additional arguments:
+      *         the package version string and the stream control structure.
+      *         size. This is needed because RPG lacks some macro feature.
+      *         Call these procedures as:
+      *             inflateInit(...: ZLIB_VERSION: %size(z_stream))
+      *
+      /if not defined(ZLIB_H_)
+      /define ZLIB_H_
+      *
+      **************************************************************************
+      *                               Constants
+      **************************************************************************
+      *
+      *  Versioning information.
+      *
+     D ZLIB_VERSION    C                   '1.2.11'
+     D ZLIB_VERNUM     C                   X'12a0'
+     D ZLIB_VER_MAJOR  C                   1
+     D ZLIB_VER_MINOR  C                   2
+     D ZLIB_VER_REVISION...
+     D                 C                   11
+     D ZLIB_VER_SUBREVISION...
+     D                 C                   0
+      *
+      *  Other equates.
+      *
+     D Z_NO_FLUSH      C                   0
+     D Z_PARTIAL_FLUSH...
+     D                 C                   1
+     D Z_SYNC_FLUSH    C                   2
+     D Z_FULL_FLUSH    C                   3
+     D Z_FINISH        C                   4
+     D Z_BLOCK         C                   5
+     D Z_TREES         C                   6
+      *
+     D Z_OK            C                   0
+     D Z_STREAM_END    C                   1
+     D Z_NEED_DICT     C                   2
+     D Z_ERRNO         C                   -1
+     D Z_STREAM_ERROR  C                   -2
+     D Z_DATA_ERROR    C                   -3
+     D Z_MEM_ERROR     C                   -4
+     D Z_BUF_ERROR     C                   -5
+     D Z_VERSION_ERROR C                   -6
+      *
+     D Z_NO_COMPRESSION...
+     D                 C                   0
+     D Z_BEST_SPEED    C                   1
+     D Z_BEST_COMPRESSION...
+     D                 C                   9
+     D Z_DEFAULT_COMPRESSION...
+     D                 C                   -1
+      *
+     D Z_FILTERED      C                   1
+     D Z_HUFFMAN_ONLY  C                   2
+     D Z_RLE           C                   3
+     D Z_DEFAULT_STRATEGY...
+     D                 C                   0
+      *
+     D Z_BINARY        C                   0
+     D Z_ASCII         C                   1
+     D Z_UNKNOWN       C                   2
+      *
+     D Z_DEFLATED      C                   8
+      *
+     D Z_NULL          C                   0
+      *
+      **************************************************************************
+      *                                 Types
+      **************************************************************************
+      *
+     D z_streamp       S               *                                        Stream struct ptr
+     D gzFile          S               *                                        File pointer
+     D gz_headerp      S               *
+     D z_off_t         S             10i 0                                      Stream offsets
+     D z_off64_t       S             20i 0                                      Stream offsets
+      *
+      **************************************************************************
+      *                               Structures
+      **************************************************************************
+      *
+      *  The GZIP encode/decode stream support structure.
+      *
+     D z_stream        DS                  align based(z_streamp)
+     D  zs_next_in                     *                                        Next input byte
+     D  zs_avail_in                  10U 0                                      Byte cnt at next_in
+     D  zs_total_in                  10U 0                                      Total bytes read
+     D  zs_next_out                    *                                        Output buffer ptr
+     D  zs_avail_out                 10U 0                                      Room left @ next_out
+     D  zs_total_out                 10U 0                                      Total bytes written
+     D  zs_msg                         *                                        Last errmsg or null
+     D  zs_state                       *                                        Internal state
+     D  zs_zalloc                      *   procptr                              Int. state allocator
+     D  zs_free                        *   procptr                              Int. state dealloc.
+     D  zs_opaque                      *                                        Private alloc. data
+     D  zs_data_type                 10i 0                                      ASC/BIN best guess
+     D  zs_adler                     10u 0                                      Uncompr. adler32 val
+     D                               10U 0                                      Reserved
+     D                               10U 0                                      Ptr. alignment
+      *
+      **************************************************************************
+      *                     Utility function prototypes
+      **************************************************************************
+      *
+     D compress        PR            10I 0 extproc('compress')
+     D  dest                      65535    options(*varsize)                    Destination buffer
+     D  destLen                      10U 0                                      Destination length
+     D  source                    65535    const options(*varsize)              Source buffer
+     D  sourceLen                    10u 0 value                                Source length
+      *
+     D compress2       PR            10I 0 extproc('compress2')
+     D  dest                      65535    options(*varsize)                    Destination buffer
+     D  destLen                      10U 0                                      Destination length
+     D  source                    65535    const options(*varsize)              Source buffer
+     D  sourceLen                    10U 0 value                                Source length
+     D  level                        10I 0 value                                Compression level
+      *
+     D compressBound   PR            10U 0 extproc('compressBound')
+     D  sourceLen                    10U 0 value
+      *
+     D uncompress      PR            10I 0 extproc('uncompress')
+     D  dest                      65535    options(*varsize)                    Destination buffer
+     D  destLen                      10U 0                                      Destination length
+     D  source                    65535    const options(*varsize)              Source buffer
+     D  sourceLen                    10U 0 value                                Source length
+      *
+     D uncompress2     PR            10I 0 extproc('uncompress2')
+     D  dest                      65535    options(*varsize)                    Destination buffer
+     D  destLen                      10U 0                                      Destination length
+     D  source                    65535    const options(*varsize)              Source buffer
+     D  sourceLen                    10U 0                                      Source length
+      *
+      /if not defined(LARGE_FILES)
+     D gzopen          PR                  extproc('gzopen')
+     D                                     like(gzFile)
+     D  path                           *   value options(*string)               File pathname
+     D  mode                           *   value options(*string)               Open mode
+      /else
+     D gzopen          PR                  extproc('gzopen64')
+     D                                     like(gzFile)
+     D  path                           *   value options(*string)               File pathname
+     D  mode                           *   value options(*string)               Open mode
+      *
+     D gzopen64        PR                  extproc('gzopen64')
+     D                                     like(gzFile)
+     D  path                           *   value options(*string)               File pathname
+     D  mode                           *   value options(*string)               Open mode
+      /endif
+      *
+     D gzdopen         PR                  extproc('gzdopen')
+     D                                     like(gzFile)
+     D  fd                           10I 0 value                                File descriptor
+     D  mode                           *   value options(*string)               Open mode
+      *
+     D gzbuffer        PR            10I 0 extproc('gzbuffer')
+     D  file                               value like(gzFile)                   File pointer
+     D  size                         10U 0 value
+      *
+     D gzsetparams     PR            10I 0 extproc('gzsetparams')
+     D  file                               value like(gzFile)                   File pointer
+     D  level                        10I 0 value
+     D  strategy                     10I 0 value
+      *
+     D gzread          PR            10I 0 extproc('gzread')
+     D  file                               value like(gzFile)                   File pointer
+     D  buf                       65535    options(*varsize)                    Buffer
+     D  len                          10u 0 value                                Buffer length
+      *
+     D gzfread          PR           20I 0 extproc('gzfread')
+     D  buf                       65535    options(*varsize)                    Buffer
+     D  size                         20u 0 value                                Buffer length
+     D  nitems                       20u 0 value                                Buffer length
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzwrite         PR            10I 0 extproc('gzwrite')
+     D  file                               value like(gzFile)                   File pointer
+     D  buf                       65535    const options(*varsize)              Buffer
+     D  len                          10u 0 value                                Buffer length
+      *
+     D gzfwrite         PR           20I 0 extproc('gzfwrite')
+     D  buf                       65535    options(*varsize)                    Buffer
+     D  size                         20u 0 value                                Buffer length
+     D  nitems                       20u 0 value                                Buffer length
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzputs          PR            10I 0 extproc('gzputs')
+     D  file                               value like(gzFile)                   File pointer
+     D  s                              *   value options(*string)               String to output
+      *
+     D gzgets          PR              *   extproc('gzgets')
+     D  file                               value like(gzFile)                   File pointer
+     D  buf                       65535    options(*varsize)                    Read buffer
+     D  len                          10i 0 value                                Buffer length
+      *
+     D gzputc          PR            10i 0 extproc('gzputc')
+     D  file                               value like(gzFile)                   File pointer
+     D  c                            10I 0 value                                Character to write
+      *
+     D gzgetc          PR            10i 0 extproc('gzgetc')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzgetc_         PR            10i 0 extproc('gzgetc_')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzungetc        PR            10i 0 extproc('gzungetc')
+     D  c                            10I 0 value                                Character to push
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzflush         PR            10i 0 extproc('gzflush')
+     D  file                               value like(gzFile)                   File pointer
+     D  flush                        10I 0 value                                Type of flush
+      *
+      /if not defined(LARGE_FILES)
+     D gzseek          PR                  extproc('gzseek')
+     D                                     like(z_off_t)
+     D  file                               value like(gzFile)                   File pointer
+     D  offset                             value like(z_off_t)                  Offset
+     D  whence                       10i 0 value                                Origin
+      /else
+     D gzseek          PR                  extproc('gzseek64')
+     D                                     like(z_off_t)
+     D  file                               value like(gzFile)                   File pointer
+     D  offset                             value like(z_off_t)                  Offset
+     D  whence                       10i 0 value                                Origin
+      *
+     D gzseek64        PR                  extproc('gzseek64')
+     D                                     like(z_off64_t)
+     D  file                               value like(gzFile)                   File pointer
+     D  offset                             value like(z_off64_t)                Offset
+     D  whence                       10i 0 value                                Origin
+      /endif
+      *
+     D gzrewind        PR            10i 0 extproc('gzrewind')
+     D  file                               value like(gzFile)                   File pointer
+      *
+      /if not defined(LARGE_FILES)
+     D gztell          PR                  extproc('gztell')
+     D                                     like(z_off_t)
+     D  file                               value like(gzFile)                   File pointer
+      /else
+     D gztell          PR                  extproc('gztell64')
+     D                                     like(z_off_t)
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gztell64        PR                  extproc('gztell64')
+     D                                     like(z_off64_t)
+     D  file                               value like(gzFile)                   File pointer
+      /endif
+      *
+      /if not defined(LARGE_FILES)
+     D gzoffset        PR                  extproc('gzoffset')
+     D                                     like(z_off_t)
+     D  file                               value like(gzFile)                   File pointer
+      /else
+     D gzoffset        PR                  extproc('gzoffset64')
+     D                                     like(z_off_t)
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzoffset64      PR                  extproc('gzoffset64')
+     D                                     like(z_off64_t)
+     D  file                               value like(gzFile)                   File pointer
+      /endif
+      *
+     D gzeof           PR            10i 0 extproc('gzeof')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzdirect        PR            10i 0 extproc('gzdirect')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzclose_r       PR            10i 0 extproc('gzclose_r')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzclose_w       PR            10i 0 extproc('gzclose_w')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzclose         PR            10i 0 extproc('gzclose')
+     D  file                               value like(gzFile)                   File pointer
+      *
+     D gzerror         PR              *   extproc('gzerror')                   Error string
+     D  file                               value like(gzFile)                   File pointer
+     D  errnum                       10I 0                                      Error code
+      *
+     D gzclearerr      PR                  extproc('gzclearerr')
+     D  file                               value like(gzFile)                   File pointer
+      *
+      **************************************************************************
+      *                        Basic function prototypes
+      **************************************************************************
+      *
+     D zlibVersion     PR              *   extproc('zlibVersion')               Version string
+      *
+     D deflateInit     PR            10I 0 extproc('deflateInit_')              Init. compression
+     D  strm                               like(z_stream)                       Compression stream
+     D  level                        10I 0 value                                Compression level
+     D  version                        *   value options(*string)               Version string
+     D  stream_size                  10i 0 value                                Stream struct. size
+      *
+     D deflate         PR            10I 0 extproc('deflate')                   Compress data
+     D  strm                               like(z_stream)                       Compression stream
+     D  flush                        10I 0 value                                Flush type required
+      *
+     D deflateEnd      PR            10I 0 extproc('deflateEnd')                Termin. compression
+     D  strm                               like(z_stream)                       Compression stream
+      *
+     D inflateInit     PR            10I 0 extproc('inflateInit_')              Init. expansion
+     D  strm                               like(z_stream)                       Expansion stream
+     D  version                        *   value options(*string)               Version string
+     D  stream_size                  10i 0 value                                Stream struct. size
+      *
+     D inflate         PR            10I 0 extproc('inflate')                   Expand data
+     D  strm                               like(z_stream)                       Expansion stream
+     D  flush                        10I 0 value                                Flush type required
+      *
+     D inflateEnd      PR            10I 0 extproc('inflateEnd')                Termin. expansion
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+      **************************************************************************
+      *                        Advanced function prototypes
+      **************************************************************************
+      *
+     D deflateInit2    PR            10I 0 extproc('deflateInit2_')             Init. compression
+     D  strm                               like(z_stream)                       Compression stream
+     D  level                        10I 0 value                                Compression level
+     D  method                       10I 0 value                                Compression method
+     D  windowBits                   10I 0 value                                log2(window size)
+     D  memLevel                     10I 0 value                                Mem/cmpress tradeoff
+     D  strategy                     10I 0 value                                Compression strategy
+     D  version                        *   value options(*string)               Version string
+     D  stream_size                  10i 0 value                                Stream struct. size
+      *
+     D deflateSetDictionary...
+     D                 PR            10I 0 extproc('deflateSetDictionary')      Init. dictionary
+     D  strm                               like(z_stream)                       Compression stream
+     D  dictionary                65535    const options(*varsize)              Dictionary bytes
+     D  dictLength                   10U 0 value                                Dictionary length
+      *
+     D deflateCopy     PR            10I 0 extproc('deflateCopy')               Compress strm 2 strm
+     D  dest                               like(z_stream)                       Destination stream
+     D  source                             like(z_stream)                       Source stream
+      *
+     D deflateReset    PR            10I 0 extproc('deflateReset')              End and init. stream
+     D  strm                               like(z_stream)                       Compression stream
+      *
+     D deflateParams   PR            10I 0 extproc('deflateParams')             Change level & strat
+     D  strm                               like(z_stream)                       Compression stream
+     D  level                        10I 0 value                                Compression level
+     D  strategy                     10I 0 value                                Compression strategy
+      *
+     D deflateTune     PR            10I 0 extproc('deflateTune')
+     D  strm                               like(z_stream)                       Compression stream
+     D  good                         10I 0 value
+     D  lazy                         10I 0 value
+     D  nice                         10I 0 value
+     D  chain                        10I 0 value
+      *
+     D deflateBound    PR            10U 0 extproc('deflateBound')              Change level & strat
+     D  strm                               like(z_stream)                       Compression stream
+     D  sourcelen                    10U 0 value                                Compression level
+      *
+     D deflatePending  PR            10I 0 extproc('deflatePending')            Change level & strat
+     D  strm                               like(z_stream)                       Compression stream
+     D  pending                      10U 0                                      Pending bytes
+     D  bits                         10I 0                                      Pending bits
+      *
+     D deflatePrime    PR            10I 0 extproc('deflatePrime')              Change level & strat
+     D  strm                               like(z_stream)                       Compression stream
+     D  bits                         10I 0 value                                # of bits to insert
+     D  value                        10I 0 value                                Bits to insert
+      *
+     D inflateInit2    PR            10I 0 extproc('inflateInit2_')             Init. expansion
+     D  strm                               like(z_stream)                       Expansion stream
+     D  windowBits                   10I 0 value                                log2(window size)
+     D  version                        *   value options(*string)               Version string
+     D  stream_size                  10i 0 value                                Stream struct. size
+      *
+     D inflateSetDictionary...
+     D                 PR            10I 0 extproc('inflateSetDictionary')      Init. dictionary
+     D  strm                               like(z_stream)                       Expansion stream
+     D  dictionary                65535    const options(*varsize)              Dictionary bytes
+     D  dictLength                   10U 0 value                                Dictionary length
+      *
+     D inflateGetDictionary...
+     D                 PR            10I 0 extproc('inflateGetDictionary')      Get dictionary
+     D  strm                               like(z_stream)                       Expansion stream
+     D  dictionary                65535    options(*varsize)                    Dictionary bytes
+     D  dictLength                   10U 0                                      Dictionary length
+      *
+     D deflateGetDictionary...
+     D                 PR            10I 0 extproc('deflateGetDictionary')      Get dictionary
+     D  strm                               like(z_stream)                       Expansion stream
+     D  dictionary                65535    options(*varsize)                    Dictionary bytes
+     D  dictLength                   10U 0                                      Dictionary length
+      *
+     D inflateSync     PR            10I 0 extproc('inflateSync')               Sync. expansion
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D inflateCopy     PR            10I 0 extproc('inflateCopy')
+     D  dest                               like(z_stream)                       Destination stream
+     D  source                             like(z_stream)                       Source stream
+      *
+     D inflateReset    PR            10I 0 extproc('inflateReset')              End and init. stream
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D inflateReset2   PR            10I 0 extproc('inflateReset2')             End and init. stream
+     D  strm                               like(z_stream)                       Expansion stream
+     D  windowBits                   10I 0 value                                Log2(buffer size)
+      *
+     D inflatePrime    PR            10I 0 extproc('inflatePrime')              Insert bits
+     D  strm                               like(z_stream)                       Expansion stream
+     D  bits                         10I 0 value                                Bit count
+     D  value                        10I 0 value                                Bits to insert
+      *
+     D inflateMark     PR            10I 0 extproc('inflateMark')               Get inflate info
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D inflateCodesUsed...
+                       PR            20U 0 extproc('inflateCodesUsed')
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D inflateValidate...
+                       PR            20U 0 extproc('inflateValidate')
+     D  strm                               like(z_stream)                       Expansion stream
+     D  check                        10I 0 value
+      *
+     D inflateGetHeader...
+                       PR            10U 0 extproc('inflateGetHeader')
+     D  strm                               like(z_stream)                       Expansion stream
+     D  head                               like(gz_headerp)
+      *
+     D deflateSetHeader...
+                       PR            10U 0 extproc('deflateSetHeader')
+     D  strm                               like(z_stream)                       Expansion stream
+     D  head                               like(gz_headerp)
+      *
+     D inflateBackInit...
+     D                 PR            10I 0 extproc('inflateBackInit_')
+     D  strm                               like(z_stream)                       Expansion stream
+     D  windowBits                   10I 0 value                                Log2(buffer size)
+     D  window                    65535    options(*varsize)                    Buffer
+     D  version                        *   value options(*string)               Version string
+     D  stream_size                  10i 0 value                                Stream struct. size
+      *
+     D inflateBack     PR            10I 0 extproc('inflateBack')
+     D  strm                               like(z_stream)                       Expansion stream
+     D  in                             *   value procptr                        Input function
+     D  in_desc                        *   value                                Input descriptor
+     D  out                            *   value procptr                        Output function
+     D  out_desc                       *   value                                Output descriptor
+      *
+     D inflateBackEnd  PR            10I 0 extproc('inflateBackEnd')
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D zlibCompileFlags...
+     D                 PR            10U 0 extproc('zlibCompileFlags')
+      *
+      **************************************************************************
+      *                        Checksum function prototypes
+      **************************************************************************
+      *
+     D adler32         PR            10U 0 extproc('adler32')                   New checksum
+     D  adler                        10U 0 value                                Old checksum
+     D  buf                       65535    const options(*varsize)              Bytes to accumulate
+     D  len                          10U 0 value                                Buffer length
+      *
+     D adler32_combine...
+                       PR            10U 0 extproc('adler32_combine')           New checksum
+     D  adler1                       10U 0 value                                Old checksum
+     D  adler2                       10U 0 value                                Old checksum
+     D  len2                         20U 0 value                                Buffer length
+      *
+     D adler32_z       PR            10U 0 extproc('adler32_z')                 New checksum
+     D  adler                        10U 0 value                                Old checksum
+     D  buf                       65535    const options(*varsize)              Bytes to accumulate
+     D  len                          20U 0 value                                Buffer length
+      *
+     D crc32           PR            10U 0 extproc('crc32')                     New checksum
+     D  crc                          10U 0 value                                Old checksum
+     D  buf                       65535    const options(*varsize)              Bytes to accumulate
+     D  len                          10U 0 value                                Buffer length
+      *
+     D crc32_combine...
+                       PR            10U 0 extproc('crc32_combine')             New checksum
+     D  crc1                         10U 0 value                                Old checksum
+     D  crc2                         10U 0 value                                Old checksum
+     D  len2                         20U 0 value                                Buffer length
+      *
+     D crc32_z         PR            10U 0 extproc('crc32_z')                   New checksum
+     D  crc                          10U 0 value                                Old checksum
+     D  buf                       65535    const options(*varsize)              Bytes to accumulate
+     D  len                          20U 0 value                                Buffer length
+      *
+      **************************************************************************
+      *                     Miscellaneous function prototypes
+      **************************************************************************
+      *
+     D zError          PR              *   extproc('zError')                    Error string
+     D  err                          10I 0 value                                Error code
+      *
+     D inflateSyncPoint...
+     D                 PR            10I 0 extproc('inflateSyncPoint')
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D get_crc_table   PR              *   extproc('get_crc_table')             Ptr to ulongs
+      *
+     D inflateUndermine...
+     D                 PR            10I 0 extproc('inflateUndermine')
+     D  strm                               like(z_stream)                       Expansion stream
+     D  arg                          10I 0 value                                Error code
+      *
+     D inflateResetKeep...
+     D                 PR            10I 0 extproc('inflateResetKeep')          End and init. stream
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+     D deflateResetKeep...
+     D                 PR            10I 0 extproc('deflateResetKeep')          End and init. stream
+     D  strm                               like(z_stream)                       Expansion stream
+      *
+      /endif
diff --git a/xs/src/png/zlib/qnx/package.qpg b/xs/src/png/zlib/qnx/package.qpg
new file mode 100644
index 000000000..31e8e90db
--- /dev/null
+++ b/xs/src/png/zlib/qnx/package.qpg
@@ -0,0 +1,141 @@
+<QPG:Generation>
+   <QPG:Options>
+      <QPG:User unattended="no" verbosity="2" listfiles="yes"/>
+      <QPG:Defaults type="qnx_package"/>
+      <QPG:Source></QPG:Source>
+      <QPG:Release number="+"/>
+      <QPG:Build></QPG:Build>
+      <QPG:FileSorting strip="yes"/>
+      <QPG:Package targets="combine"/>
+      <QPG:Repository generate="yes"/>
+      <QPG:FinalDir></QPG:FinalDir>
+      <QPG:Cleanup></QPG:Cleanup>
+   </QPG:Options>
+
+   <QPG:Responsible>
+      <QPG:Company></QPG:Company>
+      <QPG:Department></QPG:Department>
+      <QPG:Group></QPG:Group>
+      <QPG:Team></QPG:Team>
+      <QPG:Employee></QPG:Employee>
+      <QPG:EmailAddress></QPG:EmailAddress>
+   </QPG:Responsible>
+
+   <QPG:Values>
+      <QPG:Files>
+         <QPG:Add file="../zconf.h" install="/opt/include/" user="root:sys" permission="644"/>
+         <QPG:Add file="../zlib.h" install="/opt/include/" user="root:sys" permission="644"/>
+         <QPG:Add file="../libz.so.1.2.11" install="/opt/lib/" user="root:bin" permission="644"/>
+         <QPG:Add file="libz.so" install="/opt/lib/" component="dev" filetype="symlink" linkto="libz.so.1.2.11"/>
+         <QPG:Add file="libz.so.1" install="/opt/lib/" filetype="symlink" linkto="libz.so.1.2.11"/>
+         <QPG:Add file="../libz.so.1.2.11" install="/opt/lib/" component="slib"/>
+      </QPG:Files>
+
+      <QPG:PackageFilter>
+         <QPM:PackageManifest>
+            <QPM:PackageDescription>
+               <QPM:PackageType>Library</QPM:PackageType>
+               <QPM:PackageReleaseNotes></QPM:PackageReleaseNotes>
+               <QPM:PackageReleaseUrgency>Medium</QPM:PackageReleaseUrgency>
+               <QPM:PackageRepository></QPM:PackageRepository>
+               <QPM:FileVersion>2.0</QPM:FileVersion>
+            </QPM:PackageDescription>
+
+            <QPM:ProductDescription>
+               <QPM:ProductName>zlib</QPM:ProductName>
+               <QPM:ProductIdentifier>zlib</QPM:ProductIdentifier>
+               <QPM:ProductEmail>alain.bonnefoy@icbt.com</QPM:ProductEmail>
+               <QPM:VendorName>Public</QPM:VendorName>
+               <QPM:VendorInstallName>public</QPM:VendorInstallName>
+               <QPM:VendorURL>www.gzip.org/zlib</QPM:VendorURL>
+               <QPM:VendorEmbedURL></QPM:VendorEmbedURL>
+               <QPM:VendorEmail></QPM:VendorEmail>
+               <QPM:AuthorName>Jean-Loup Gailly,Mark Adler</QPM:AuthorName>
+               <QPM:AuthorURL>www.gzip.org/zlib</QPM:AuthorURL>
+               <QPM:AuthorEmbedURL></QPM:AuthorEmbedURL>
+               <QPM:AuthorEmail>zlib@gzip.org</QPM:AuthorEmail>
+               <QPM:ProductIconSmall></QPM:ProductIconSmall>
+               <QPM:ProductIconLarge></QPM:ProductIconLarge>
+               <QPM:ProductDescriptionShort>A massively spiffy yet delicately unobtrusive compression library.</QPM:ProductDescriptionShort>
+               <QPM:ProductDescriptionLong>zlib is designed to be a free, general-purpose, legally unencumbered, lossless data compression library for use on virtually any computer hardware and operating system.</QPM:ProductDescriptionLong>
+               <QPM:ProductDescriptionURL>http://www.gzip.org/zlib</QPM:ProductDescriptionURL>
+               <QPM:ProductDescriptionEmbedURL></QPM:ProductDescriptionEmbedURL>
+            </QPM:ProductDescription>
+
+            <QPM:ReleaseDescription>
+               <QPM:ReleaseVersion>1.2.11</QPM:ReleaseVersion>
+               <QPM:ReleaseUrgency>Medium</QPM:ReleaseUrgency>
+               <QPM:ReleaseStability>Stable</QPM:ReleaseStability>
+               <QPM:ReleaseNoteMinor></QPM:ReleaseNoteMinor>
+               <QPM:ReleaseNoteMajor></QPM:ReleaseNoteMajor>
+               <QPM:ExcludeCountries>
+                  <QPM:Country></QPM:Country>
+               </QPM:ExcludeCountries>
+
+               <QPM:ReleaseCopyright>No License</QPM:ReleaseCopyright>
+            </QPM:ReleaseDescription>
+
+            <QPM:ContentDescription>
+               <QPM:ContentTopic xmlmultiple="true">Software Development/Libraries and Extensions/C Libraries</QPM:ContentTopic>
+               <QPM:ContentKeyword>zlib,compression</QPM:ContentKeyword>
+               <QPM:TargetOS>qnx6</QPM:TargetOS>
+               <QPM:HostOS>qnx6</QPM:HostOS>
+               <QPM:DisplayEnvironment xmlmultiple="true">None</QPM:DisplayEnvironment>
+               <QPM:TargetAudience xmlmultiple="true">Developer</QPM:TargetAudience>
+            </QPM:ContentDescription>
+         </QPM:PackageManifest>
+      </QPG:PackageFilter>
+
+      <QPG:PackageFilter proc="none" target="none">
+         <QPM:PackageManifest>
+            <QPM:ProductInstallationDependencies>
+               <QPM:ProductRequirements></QPM:ProductRequirements>
+            </QPM:ProductInstallationDependencies>
+
+            <QPM:ProductInstallationProcedure>
+               <QPM:Script xmlmultiple="true">
+                  <QPM:ScriptName></QPM:ScriptName>
+                  <QPM:ScriptType>Install</QPM:ScriptType>
+                  <QPM:ScriptTiming>Post</QPM:ScriptTiming>
+                  <QPM:ScriptBlocking>No</QPM:ScriptBlocking>
+                  <QPM:ScriptResult>Ignore</QPM:ScriptResult>
+                  <QPM:ShortDescription></QPM:ShortDescription>
+                  <QPM:UseBinaries>No</QPM:UseBinaries>
+                  <QPM:Priority>Optional</QPM:Priority>
+               </QPM:Script>
+            </QPM:ProductInstallationProcedure>
+         </QPM:PackageManifest>
+
+         <QPM:Launch>
+         </QPM:Launch>
+      </QPG:PackageFilter>
+
+      <QPG:PackageFilter type="core" component="none">
+         <QPM:PackageManifest>
+            <QPM:ProductInstallationProcedure>
+	       <QPM:OrderDependency xmlmultiple="true">
+	          <QPM:Order>InstallOver</QPM:Order>
+	          <QPM:Product>zlib</QPM:Product>
+	       </QPM:OrderDependency>
+            </QPM:ProductInstallationProcedure>
+         </QPM:PackageManifest>
+
+         <QPM:Launch>
+         </QPM:Launch>
+      </QPG:PackageFilter>
+
+      <QPG:PackageFilter type="core" component="dev">
+         <QPM:PackageManifest>
+            <QPM:ProductInstallationProcedure>
+	       <QPM:OrderDependency xmlmultiple="true">
+	          <QPM:Order>InstallOver</QPM:Order>
+	          <QPM:Product>zlib-dev</QPM:Product>
+	       </QPM:OrderDependency>
+            </QPM:ProductInstallationProcedure>
+         </QPM:PackageManifest>
+
+         <QPM:Launch>
+         </QPM:Launch>
+      </QPG:PackageFilter>
+   </QPG:Values>
+</QPG:Generation>
diff --git a/xs/src/png/zlib/treebuild.xml b/xs/src/png/zlib/treebuild.xml
new file mode 100644
index 000000000..fd75525f9
--- /dev/null
+++ b/xs/src/png/zlib/treebuild.xml
@@ -0,0 +1,116 @@
+<?xml version="1.0" ?>
+<package name="zlib" version="1.2.11">
+    <library name="zlib" dlversion="1.2.11" dlname="z">
+	<property name="description"> zip compression library </property>
+	<property name="include-target-dir" value="$(@PACKAGE/install-includedir)" />
+
+	<!-- fixme: not implemented yet -->
+	<property name="compiler/c/inline" value="yes" />
+
+	<include-file name="zlib.h" scope="public" mode="644" />
+	<include-file name="zconf.h" scope="public" mode="644" />
+
+	<source name="adler32.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	</source>
+	<source name="compress.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	</source>
+	<source name="crc32.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="crc32.h" />
+	</source>
+	<source name="gzclose.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="gzguts.h" />
+	</source>
+	<source name="gzlib.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="gzguts.h" />
+	</source>
+	<source name="gzread.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="gzguts.h" />
+	</source>
+	<source name="gzwrite.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="gzguts.h" />
+	</source>
+	<source name="uncompr.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	</source>
+	<source name="deflate.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	    <depend name="deflate.h" />
+	</source>
+	<source name="trees.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	    <depend name="deflate.h" />
+	    <depend name="trees.h" />
+	</source>
+	<source name="zutil.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	</source>
+	<source name="inflate.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	    <depend name="inftrees.h" />
+	    <depend name="inflate.h" />
+	    <depend name="inffast.h" />
+	</source>
+	<source name="infback.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	    <depend name="inftrees.h" />
+	    <depend name="inflate.h" />
+	    <depend name="inffast.h" />
+	</source>
+	<source name="inftrees.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	    <depend name="inftrees.h" />
+	</source>
+	<source name="inffast.c">
+	    <depend name="zlib.h" />
+	    <depend name="zconf.h" />
+	    <depend name="zutil.h" />
+	    <depend name="inftrees.h" />
+	    <depend name="inflate.h" />
+	    <depend name="inffast.h" />
+	</source>
+    </library>
+</package>
+
+<!--
+CFLAGS=-O
+#CFLAGS=-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7
+#CFLAGS=-g -DZLIB_DEBUG
+#CFLAGS=-O3 -Wall -Wwrite-strings -Wpointer-arith -Wconversion \
+#           -Wstrict-prototypes -Wmissing-prototypes
+
+# OBJA =
+# to use the asm code: make OBJA=match.o
+#
+match.o: match.S
+	$(CPP) match.S > _match.s
+	$(CC) -c _match.s
+	mv _match.o match.o
+	rm -f _match.s
+-->
diff --git a/xs/src/png/zlib/trees.c b/xs/src/png/zlib/trees.c
new file mode 100644
index 000000000..50cf4b457
--- /dev/null
+++ b/xs/src/png/zlib/trees.c
@@ -0,0 +1,1203 @@
+/* trees.c -- output deflated data using Huffman coding
+ * Copyright (C) 1995-2017 Jean-loup Gailly
+ * detect_data_type() function provided freely by Cosmin Truta, 2006
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process uses several Huffman trees. The more
+ *      common source values are represented by shorter bit sequences.
+ *
+ *      Each code tree is stored in a compressed form which is itself
+ * a Huffman encoding of the lengths of all the code strings (in
+ * ascending order by source values).  The actual code strings are
+ * reconstructed from the lengths in the inflate process, as described
+ * in the deflate specification.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
+ *      Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
+ *
+ *      Storer, James A.
+ *          Data Compression:  Methods and Theory, pp. 49-50.
+ *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
+ *
+ *      Sedgewick, R.
+ *          Algorithms, p290.
+ *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
+ */
+
+/* @(#) $Id$ */
+
+/* #define GEN_TREES_H */
+
+#include "deflate.h"
+
+#ifdef ZLIB_DEBUG
+#  include <ctype.h>
+#endif
+
+/* ===========================================================================
+ * Constants
+ */
+
+#define MAX_BL_BITS 7
+/* Bit length codes must not exceed MAX_BL_BITS bits */
+
+#define END_BLOCK 256
+/* end of block literal code */
+
+#define REP_3_6      16
+/* repeat previous bit length 3-6 times (2 bits of repeat count) */
+
+#define REPZ_3_10    17
+/* repeat a zero length 3-10 times  (3 bits of repeat count) */
+
+#define REPZ_11_138  18
+/* repeat a zero length 11-138 times  (7 bits of repeat count) */
+
+local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
+   = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
+
+local const int extra_dbits[D_CODES] /* extra bits for each distance code */
+   = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
+
+local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
+   = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
+
+local const uch bl_order[BL_CODES]
+   = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
+/* The lengths of the bit length codes are sent in order of decreasing
+ * probability, to avoid transmitting the lengths for unused bit length codes.
+ */
+
+/* ===========================================================================
+ * Local data. These are initialized only once.
+ */
+
+#define DIST_CODE_LEN  512 /* see definition of array dist_code below */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+/* non ANSI compilers may not accept trees.h */
+
+local ct_data static_ltree[L_CODES+2];
+/* The static literal tree. Since the bit lengths are imposed, there is no
+ * need for the L_CODES extra codes used during heap construction. However
+ * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
+ * below).
+ */
+
+local ct_data static_dtree[D_CODES];
+/* The static distance tree. (Actually a trivial tree since all codes use
+ * 5 bits.)
+ */
+
+uch _dist_code[DIST_CODE_LEN];
+/* Distance codes. The first 256 values correspond to the distances
+ * 3 .. 258, the last 256 values correspond to the top 8 bits of
+ * the 15 bit distances.
+ */
+
+uch _length_code[MAX_MATCH-MIN_MATCH+1];
+/* length code for each normalized match length (0 == MIN_MATCH) */
+
+local int base_length[LENGTH_CODES];
+/* First normalized length for each code (0 = MIN_MATCH) */
+
+local int base_dist[D_CODES];
+/* First normalized distance for each code (0 = distance of 1) */
+
+#else
+#  include "trees.h"
+#endif /* GEN_TREES_H */
+
+struct static_tree_desc_s {
+    const ct_data *static_tree;  /* static tree or NULL */
+    const intf *extra_bits;      /* extra bits for each code or NULL */
+    int     extra_base;          /* base index for extra_bits */
+    int     elems;               /* max number of elements in the tree */
+    int     max_length;          /* max bit length for the codes */
+};
+
+local const static_tree_desc  static_l_desc =
+{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
+
+local const static_tree_desc  static_d_desc =
+{static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};
+
+local const static_tree_desc  static_bl_desc =
+{(const ct_data *)0, extra_blbits, 0,   BL_CODES, MAX_BL_BITS};
+
+/* ===========================================================================
+ * Local (static) routines in this file.
+ */
+
+local void tr_static_init OF((void));
+local void init_block     OF((deflate_state *s));
+local void pqdownheap     OF((deflate_state *s, ct_data *tree, int k));
+local void gen_bitlen     OF((deflate_state *s, tree_desc *desc));
+local void gen_codes      OF((ct_data *tree, int max_code, ushf *bl_count));
+local void build_tree     OF((deflate_state *s, tree_desc *desc));
+local void scan_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+local void send_tree      OF((deflate_state *s, ct_data *tree, int max_code));
+local int  build_bl_tree  OF((deflate_state *s));
+local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
+                              int blcodes));
+local void compress_block OF((deflate_state *s, const ct_data *ltree,
+                              const ct_data *dtree));
+local int  detect_data_type OF((deflate_state *s));
+local unsigned bi_reverse OF((unsigned value, int length));
+local void bi_windup      OF((deflate_state *s));
+local void bi_flush       OF((deflate_state *s));
+
+#ifdef GEN_TREES_H
+local void gen_trees_header OF((void));
+#endif
+
+#ifndef ZLIB_DEBUG
+#  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
+   /* Send a code of the given tree. c and tree must not have side effects */
+
+#else /* !ZLIB_DEBUG */
+#  define send_code(s, c, tree) \
+     { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
+       send_bits(s, tree[c].Code, tree[c].Len); }
+#endif
+
+/* ===========================================================================
+ * Output a short LSB first on the stream.
+ * IN assertion: there is enough room in pendingBuf.
+ */
+#define put_short(s, w) { \
+    put_byte(s, (uch)((w) & 0xff)); \
+    put_byte(s, (uch)((ush)(w) >> 8)); \
+}
+
+/* ===========================================================================
+ * Send a value on a given number of bits.
+ * IN assertion: length <= 16 and value fits in length bits.
+ */
+#ifdef ZLIB_DEBUG
+local void send_bits      OF((deflate_state *s, int value, int length));
+
+local void send_bits(s, value, length)
+    deflate_state *s;
+    int value;  /* value to send */
+    int length; /* number of bits */
+{
+    Tracevv((stderr," l %2d v %4x ", length, value));
+    Assert(length > 0 && length <= 15, "invalid length");
+    s->bits_sent += (ulg)length;
+
+    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
+     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
+     * unused bits in value.
+     */
+    if (s->bi_valid > (int)Buf_size - length) {
+        s->bi_buf |= (ush)value << s->bi_valid;
+        put_short(s, s->bi_buf);
+        s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
+        s->bi_valid += length - Buf_size;
+    } else {
+        s->bi_buf |= (ush)value << s->bi_valid;
+        s->bi_valid += length;
+    }
+}
+#else /* !ZLIB_DEBUG */
+
+#define send_bits(s, value, length) \
+{ int len = length;\
+  if (s->bi_valid > (int)Buf_size - len) {\
+    int val = (int)value;\
+    s->bi_buf |= (ush)val << s->bi_valid;\
+    put_short(s, s->bi_buf);\
+    s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
+    s->bi_valid += len - Buf_size;\
+  } else {\
+    s->bi_buf |= (ush)(value) << s->bi_valid;\
+    s->bi_valid += len;\
+  }\
+}
+#endif /* ZLIB_DEBUG */
+
+
+/* the arguments must not have side effects */
+
+/* ===========================================================================
+ * Initialize the various 'constant' tables.
+ */
+local void tr_static_init()
+{
+#if defined(GEN_TREES_H) || !defined(STDC)
+    static int static_init_done = 0;
+    int n;        /* iterates over tree elements */
+    int bits;     /* bit counter */
+    int length;   /* length value */
+    int code;     /* code value */
+    int dist;     /* distance index */
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    if (static_init_done) return;
+
+    /* For some embedded targets, global variables are not initialized: */
+#ifdef NO_INIT_GLOBAL_POINTERS
+    static_l_desc.static_tree = static_ltree;
+    static_l_desc.extra_bits = extra_lbits;
+    static_d_desc.static_tree = static_dtree;
+    static_d_desc.extra_bits = extra_dbits;
+    static_bl_desc.extra_bits = extra_blbits;
+#endif
+
+    /* Initialize the mapping length (0..255) -> length code (0..28) */
+    length = 0;
+    for (code = 0; code < LENGTH_CODES-1; code++) {
+        base_length[code] = length;
+        for (n = 0; n < (1<<extra_lbits[code]); n++) {
+            _length_code[length++] = (uch)code;
+        }
+    }
+    Assert (length == 256, "tr_static_init: length != 256");
+    /* Note that the length 255 (match length 258) can be represented
+     * in two different ways: code 284 + 5 bits or code 285, so we
+     * overwrite length_code[255] to use the best encoding:
+     */
+    _length_code[length-1] = (uch)code;
+
+    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
+    dist = 0;
+    for (code = 0 ; code < 16; code++) {
+        base_dist[code] = dist;
+        for (n = 0; n < (1<<extra_dbits[code]); n++) {
+            _dist_code[dist++] = (uch)code;
+        }
+    }
+    Assert (dist == 256, "tr_static_init: dist != 256");
+    dist >>= 7; /* from now on, all distances are divided by 128 */
+    for ( ; code < D_CODES; code++) {
+        base_dist[code] = dist << 7;
+        for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
+            _dist_code[256 + dist++] = (uch)code;
+        }
+    }
+    Assert (dist == 256, "tr_static_init: 256+dist != 512");
+
+    /* Construct the codes of the static literal tree */
+    for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
+    n = 0;
+    while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
+    while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
+    while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
+    while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
+    /* Codes 286 and 287 do not exist, but we must include them in the
+     * tree construction to get a canonical Huffman tree (longest code
+     * all ones)
+     */
+    gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
+
+    /* The static distance tree is trivial: */
+    for (n = 0; n < D_CODES; n++) {
+        static_dtree[n].Len = 5;
+        static_dtree[n].Code = bi_reverse((unsigned)n, 5);
+    }
+    static_init_done = 1;
+
+#  ifdef GEN_TREES_H
+    gen_trees_header();
+#  endif
+#endif /* defined(GEN_TREES_H) || !defined(STDC) */
+}
+
+/* ===========================================================================
+ * Genererate the file trees.h describing the static trees.
+ */
+#ifdef GEN_TREES_H
+#  ifndef ZLIB_DEBUG
+#    include <stdio.h>
+#  endif
+
+#  define SEPARATOR(i, last, width) \
+      ((i) == (last)? "\n};\n\n" :    \
+       ((i) % (width) == (width)-1 ? ",\n" : ", "))
+
+void gen_trees_header()
+{
+    FILE *header = fopen("trees.h", "w");
+    int i;
+
+    Assert (header != NULL, "Can't open trees.h");
+    fprintf(header,
+            "/* header created automatically with -DGEN_TREES_H */\n\n");
+
+    fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
+    for (i = 0; i < L_CODES+2; i++) {
+        fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
+                static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
+    }
+
+    fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
+    for (i = 0; i < D_CODES; i++) {
+        fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
+                static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
+    }
+
+    fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
+    for (i = 0; i < DIST_CODE_LEN; i++) {
+        fprintf(header, "%2u%s", _dist_code[i],
+                SEPARATOR(i, DIST_CODE_LEN-1, 20));
+    }
+
+    fprintf(header,
+        "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
+    for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
+        fprintf(header, "%2u%s", _length_code[i],
+                SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
+    }
+
+    fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
+    for (i = 0; i < LENGTH_CODES; i++) {
+        fprintf(header, "%1u%s", base_length[i],
+                SEPARATOR(i, LENGTH_CODES-1, 20));
+    }
+
+    fprintf(header, "local const int base_dist[D_CODES] = {\n");
+    for (i = 0; i < D_CODES; i++) {
+        fprintf(header, "%5u%s", base_dist[i],
+                SEPARATOR(i, D_CODES-1, 10));
+    }
+
+    fclose(header);
+}
+#endif /* GEN_TREES_H */
+
+/* ===========================================================================
+ * Initialize the tree data structures for a new zlib stream.
+ */
+void ZLIB_INTERNAL _tr_init(s)
+    deflate_state *s;
+{
+    tr_static_init();
+
+    s->l_desc.dyn_tree = s->dyn_ltree;
+    s->l_desc.stat_desc = &static_l_desc;
+
+    s->d_desc.dyn_tree = s->dyn_dtree;
+    s->d_desc.stat_desc = &static_d_desc;
+
+    s->bl_desc.dyn_tree = s->bl_tree;
+    s->bl_desc.stat_desc = &static_bl_desc;
+
+    s->bi_buf = 0;
+    s->bi_valid = 0;
+#ifdef ZLIB_DEBUG
+    s->compressed_len = 0L;
+    s->bits_sent = 0L;
+#endif
+
+    /* Initialize the first block of the first file: */
+    init_block(s);
+}
+
+/* ===========================================================================
+ * Initialize a new block.
+ */
+local void init_block(s)
+    deflate_state *s;
+{
+    int n; /* iterates over tree elements */
+
+    /* Initialize the trees. */
+    for (n = 0; n < L_CODES;  n++) s->dyn_ltree[n].Freq = 0;
+    for (n = 0; n < D_CODES;  n++) s->dyn_dtree[n].Freq = 0;
+    for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
+
+    s->dyn_ltree[END_BLOCK].Freq = 1;
+    s->opt_len = s->static_len = 0L;
+    s->last_lit = s->matches = 0;
+}
+
+#define SMALLEST 1
+/* Index within the heap array of least frequent node in the Huffman tree */
+
+
+/* ===========================================================================
+ * Remove the smallest element from the heap and recreate the heap with
+ * one less element. Updates heap and heap_len.
+ */
+#define pqremove(s, tree, top) \
+{\
+    top = s->heap[SMALLEST]; \
+    s->heap[SMALLEST] = s->heap[s->heap_len--]; \
+    pqdownheap(s, tree, SMALLEST); \
+}
+
+/* ===========================================================================
+ * Compares to subtrees, using the tree depth as tie breaker when
+ * the subtrees have equal frequency. This minimizes the worst case length.
+ */
+#define smaller(tree, n, m, depth) \
+   (tree[n].Freq < tree[m].Freq || \
+   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
+
+/* ===========================================================================
+ * Restore the heap property by moving down the tree starting at node k,
+ * exchanging a node with the smallest of its two sons if necessary, stopping
+ * when the heap property is re-established (each father smaller than its
+ * two sons).
+ */
+local void pqdownheap(s, tree, k)
+    deflate_state *s;
+    ct_data *tree;  /* the tree to restore */
+    int k;               /* node to move down */
+{
+    int v = s->heap[k];
+    int j = k << 1;  /* left son of k */
+    while (j <= s->heap_len) {
+        /* Set j to the smallest of the two sons: */
+        if (j < s->heap_len &&
+            smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
+            j++;
+        }
+        /* Exit if v is smaller than both sons */
+        if (smaller(tree, v, s->heap[j], s->depth)) break;
+
+        /* Exchange v with the smallest son */
+        s->heap[k] = s->heap[j];  k = j;
+
+        /* And continue down the tree, setting j to the left son of k */
+        j <<= 1;
+    }
+    s->heap[k] = v;
+}
+
+/* ===========================================================================
+ * Compute the optimal bit lengths for a tree and update the total bit length
+ * for the current block.
+ * IN assertion: the fields freq and dad are set, heap[heap_max] and
+ *    above are the tree nodes sorted by increasing frequency.
+ * OUT assertions: the field len is set to the optimal bit length, the
+ *     array bl_count contains the frequencies for each bit length.
+ *     The length opt_len is updated; static_len is also updated if stree is
+ *     not null.
+ */
+local void gen_bitlen(s, desc)
+    deflate_state *s;
+    tree_desc *desc;    /* the tree descriptor */
+{
+    ct_data *tree        = desc->dyn_tree;
+    int max_code         = desc->max_code;
+    const ct_data *stree = desc->stat_desc->static_tree;
+    const intf *extra    = desc->stat_desc->extra_bits;
+    int base             = desc->stat_desc->extra_base;
+    int max_length       = desc->stat_desc->max_length;
+    int h;              /* heap index */
+    int n, m;           /* iterate over the tree elements */
+    int bits;           /* bit length */
+    int xbits;          /* extra bits */
+    ush f;              /* frequency */
+    int overflow = 0;   /* number of elements with bit length too large */
+
+    for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
+
+    /* In a first pass, compute the optimal bit lengths (which may
+     * overflow in the case of the bit length tree).
+     */
+    tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
+
+    for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
+        n = s->heap[h];
+        bits = tree[tree[n].Dad].Len + 1;
+        if (bits > max_length) bits = max_length, overflow++;
+        tree[n].Len = (ush)bits;
+        /* We overwrite tree[n].Dad which is no longer needed */
+
+        if (n > max_code) continue; /* not a leaf node */
+
+        s->bl_count[bits]++;
+        xbits = 0;
+        if (n >= base) xbits = extra[n-base];
+        f = tree[n].Freq;
+        s->opt_len += (ulg)f * (unsigned)(bits + xbits);
+        if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
+    }
+    if (overflow == 0) return;
+
+    Tracev((stderr,"\nbit length overflow\n"));
+    /* This happens for example on obj2 and pic of the Calgary corpus */
+
+    /* Find the first bit length which could increase: */
+    do {
+        bits = max_length-1;
+        while (s->bl_count[bits] == 0) bits--;
+        s->bl_count[bits]--;      /* move one leaf down the tree */
+        s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
+        s->bl_count[max_length]--;
+        /* The brother of the overflow item also moves one step up,
+         * but this does not affect bl_count[max_length]
+         */
+        overflow -= 2;
+    } while (overflow > 0);
+
+    /* Now recompute all bit lengths, scanning in increasing frequency.
+     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
+     * lengths instead of fixing only the wrong ones. This idea is taken
+     * from 'ar' written by Haruhiko Okumura.)
+     */
+    for (bits = max_length; bits != 0; bits--) {
+        n = s->bl_count[bits];
+        while (n != 0) {
+            m = s->heap[--h];
+            if (m > max_code) continue;
+            if ((unsigned) tree[m].Len != (unsigned) bits) {
+                Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
+                s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq;
+                tree[m].Len = (ush)bits;
+            }
+            n--;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Generate the codes for a given tree and bit counts (which need not be
+ * optimal).
+ * IN assertion: the array bl_count contains the bit length statistics for
+ * the given tree and the field len is set for all tree elements.
+ * OUT assertion: the field code is set for all tree elements of non
+ *     zero code length.
+ */
+local void gen_codes (tree, max_code, bl_count)
+    ct_data *tree;             /* the tree to decorate */
+    int max_code;              /* largest code with non zero frequency */
+    ushf *bl_count;            /* number of codes at each bit length */
+{
+    ush next_code[MAX_BITS+1]; /* next code value for each bit length */
+    unsigned code = 0;         /* running code value */
+    int bits;                  /* bit index */
+    int n;                     /* code index */
+
+    /* The distribution counts are first used to generate the code values
+     * without bit reversal.
+     */
+    for (bits = 1; bits <= MAX_BITS; bits++) {
+        code = (code + bl_count[bits-1]) << 1;
+        next_code[bits] = (ush)code;
+    }
+    /* Check that the bit counts in bl_count are consistent. The last code
+     * must be all ones.
+     */
+    Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
+            "inconsistent bit counts");
+    Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
+
+    for (n = 0;  n <= max_code; n++) {
+        int len = tree[n].Len;
+        if (len == 0) continue;
+        /* Now reverse the bits */
+        tree[n].Code = (ush)bi_reverse(next_code[len]++, len);
+
+        Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
+             n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
+    }
+}
+
+/* ===========================================================================
+ * Construct one Huffman tree and assigns the code bit strings and lengths.
+ * Update the total bit length for the current block.
+ * IN assertion: the field freq is set for all tree elements.
+ * OUT assertions: the fields len and code are set to the optimal bit length
+ *     and corresponding code. The length opt_len is updated; static_len is
+ *     also updated if stree is not null. The field max_code is set.
+ */
+local void build_tree(s, desc)
+    deflate_state *s;
+    tree_desc *desc; /* the tree descriptor */
+{
+    ct_data *tree         = desc->dyn_tree;
+    const ct_data *stree  = desc->stat_desc->static_tree;
+    int elems             = desc->stat_desc->elems;
+    int n, m;          /* iterate over heap elements */
+    int max_code = -1; /* largest code with non zero frequency */
+    int node;          /* new node being created */
+
+    /* Construct the initial heap, with least frequent element in
+     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
+     * heap[0] is not used.
+     */
+    s->heap_len = 0, s->heap_max = HEAP_SIZE;
+
+    for (n = 0; n < elems; n++) {
+        if (tree[n].Freq != 0) {
+            s->heap[++(s->heap_len)] = max_code = n;
+            s->depth[n] = 0;
+        } else {
+            tree[n].Len = 0;
+        }
+    }
+
+    /* The pkzip format requires that at least one distance code exists,
+     * and that at least one bit should be sent even if there is only one
+     * possible code. So to avoid special checks later on we force at least
+     * two codes of non zero frequency.
+     */
+    while (s->heap_len < 2) {
+        node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
+        tree[node].Freq = 1;
+        s->depth[node] = 0;
+        s->opt_len--; if (stree) s->static_len -= stree[node].Len;
+        /* node is 0 or 1 so it does not have extra bits */
+    }
+    desc->max_code = max_code;
+
+    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
+     * establish sub-heaps of increasing lengths:
+     */
+    for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
+
+    /* Construct the Huffman tree by repeatedly combining the least two
+     * frequent nodes.
+     */
+    node = elems;              /* next internal node of the tree */
+    do {
+        pqremove(s, tree, n);  /* n = node of least frequency */
+        m = s->heap[SMALLEST]; /* m = node of next least frequency */
+
+        s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
+        s->heap[--(s->heap_max)] = m;
+
+        /* Create a new node father of n and m */
+        tree[node].Freq = tree[n].Freq + tree[m].Freq;
+        s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?
+                                s->depth[n] : s->depth[m]) + 1);
+        tree[n].Dad = tree[m].Dad = (ush)node;
+#ifdef DUMP_BL_TREE
+        if (tree == s->bl_tree) {
+            fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
+                    node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
+        }
+#endif
+        /* and insert the new node in the heap */
+        s->heap[SMALLEST] = node++;
+        pqdownheap(s, tree, SMALLEST);
+
+    } while (s->heap_len >= 2);
+
+    s->heap[--(s->heap_max)] = s->heap[SMALLEST];
+
+    /* At this point, the fields freq and dad are set. We can now
+     * generate the bit lengths.
+     */
+    gen_bitlen(s, (tree_desc *)desc);
+
+    /* The field len is now set, we can generate the bit codes */
+    gen_codes ((ct_data *)tree, max_code, s->bl_count);
+}
+
+/* ===========================================================================
+ * Scan a literal or distance tree to determine the frequencies of the codes
+ * in the bit length tree.
+ */
+local void scan_tree (s, tree, max_code)
+    deflate_state *s;
+    ct_data *tree;   /* the tree to be scanned */
+    int max_code;    /* and its largest code of non zero frequency */
+{
+    int n;                     /* iterates over all tree elements */
+    int prevlen = -1;          /* last emitted length */
+    int curlen;                /* length of current code */
+    int nextlen = tree[0].Len; /* length of next code */
+    int count = 0;             /* repeat count of the current code */
+    int max_count = 7;         /* max repeat count */
+    int min_count = 4;         /* min repeat count */
+
+    if (nextlen == 0) max_count = 138, min_count = 3;
+    tree[max_code+1].Len = (ush)0xffff; /* guard */
+
+    for (n = 0; n <= max_code; n++) {
+        curlen = nextlen; nextlen = tree[n+1].Len;
+        if (++count < max_count && curlen == nextlen) {
+            continue;
+        } else if (count < min_count) {
+            s->bl_tree[curlen].Freq += count;
+        } else if (curlen != 0) {
+            if (curlen != prevlen) s->bl_tree[curlen].Freq++;
+            s->bl_tree[REP_3_6].Freq++;
+        } else if (count <= 10) {
+            s->bl_tree[REPZ_3_10].Freq++;
+        } else {
+            s->bl_tree[REPZ_11_138].Freq++;
+        }
+        count = 0; prevlen = curlen;
+        if (nextlen == 0) {
+            max_count = 138, min_count = 3;
+        } else if (curlen == nextlen) {
+            max_count = 6, min_count = 3;
+        } else {
+            max_count = 7, min_count = 4;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Send a literal or distance tree in compressed form, using the codes in
+ * bl_tree.
+ */
+local void send_tree (s, tree, max_code)
+    deflate_state *s;
+    ct_data *tree; /* the tree to be scanned */
+    int max_code;       /* and its largest code of non zero frequency */
+{
+    int n;                     /* iterates over all tree elements */
+    int prevlen = -1;          /* last emitted length */
+    int curlen;                /* length of current code */
+    int nextlen = tree[0].Len; /* length of next code */
+    int count = 0;             /* repeat count of the current code */
+    int max_count = 7;         /* max repeat count */
+    int min_count = 4;         /* min repeat count */
+
+    /* tree[max_code+1].Len = -1; */  /* guard already set */
+    if (nextlen == 0) max_count = 138, min_count = 3;
+
+    for (n = 0; n <= max_code; n++) {
+        curlen = nextlen; nextlen = tree[n+1].Len;
+        if (++count < max_count && curlen == nextlen) {
+            continue;
+        } else if (count < min_count) {
+            do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
+
+        } else if (curlen != 0) {
+            if (curlen != prevlen) {
+                send_code(s, curlen, s->bl_tree); count--;
+            }
+            Assert(count >= 3 && count <= 6, " 3_6?");
+            send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
+
+        } else if (count <= 10) {
+            send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
+
+        } else {
+            send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
+        }
+        count = 0; prevlen = curlen;
+        if (nextlen == 0) {
+            max_count = 138, min_count = 3;
+        } else if (curlen == nextlen) {
+            max_count = 6, min_count = 3;
+        } else {
+            max_count = 7, min_count = 4;
+        }
+    }
+}
+
+/* ===========================================================================
+ * Construct the Huffman tree for the bit lengths and return the index in
+ * bl_order of the last bit length code to send.
+ */
+local int build_bl_tree(s)
+    deflate_state *s;
+{
+    int max_blindex;  /* index of last bit length code of non zero freq */
+
+    /* Determine the bit length frequencies for literal and distance trees */
+    scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
+    scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
+
+    /* Build the bit length tree: */
+    build_tree(s, (tree_desc *)(&(s->bl_desc)));
+    /* opt_len now includes the length of the tree representations, except
+     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+     */
+
+    /* Determine the number of bit length codes to send. The pkzip format
+     * requires that at least 4 bit length codes be sent. (appnote.txt says
+     * 3 but the actual value used is 4.)
+     */
+    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
+        if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
+    }
+    /* Update opt_len to include the bit length tree and counts */
+    s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4;
+    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
+            s->opt_len, s->static_len));
+
+    return max_blindex;
+}
+
+/* ===========================================================================
+ * Send the header for a block using dynamic Huffman trees: the counts, the
+ * lengths of the bit length codes, the literal tree and the distance tree.
+ * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
+ */
+local void send_all_trees(s, lcodes, dcodes, blcodes)
+    deflate_state *s;
+    int lcodes, dcodes, blcodes; /* number of codes for each tree */
+{
+    int rank;                    /* index in bl_order */
+
+    Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
+    Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
+            "too many codes");
+    Tracev((stderr, "\nbl counts: "));
+    send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
+    send_bits(s, dcodes-1,   5);
+    send_bits(s, blcodes-4,  4); /* not -3 as stated in appnote.txt */
+    for (rank = 0; rank < blcodes; rank++) {
+        Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
+        send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
+    }
+    Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
+
+    send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
+    Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
+
+    send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
+    Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
+}
+
+/* ===========================================================================
+ * Send a stored block
+ */
+void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)
+    deflate_state *s;
+    charf *buf;       /* input block */
+    ulg stored_len;   /* length of input block */
+    int last;         /* one if this is the last block for a file */
+{
+    send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
+    bi_windup(s);        /* align on byte boundary */
+    put_short(s, (ush)stored_len);
+    put_short(s, (ush)~stored_len);
+    zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
+    s->pending += stored_len;
+#ifdef ZLIB_DEBUG
+    s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
+    s->compressed_len += (stored_len + 4) << 3;
+    s->bits_sent += 2*16;
+    s->bits_sent += stored_len<<3;
+#endif
+}
+
+/* ===========================================================================
+ * Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
+ */
+void ZLIB_INTERNAL _tr_flush_bits(s)
+    deflate_state *s;
+{
+    bi_flush(s);
+}
+
+/* ===========================================================================
+ * Send one empty static block to give enough lookahead for inflate.
+ * This takes 10 bits, of which 7 may remain in the bit buffer.
+ */
+void ZLIB_INTERNAL _tr_align(s)
+    deflate_state *s;
+{
+    send_bits(s, STATIC_TREES<<1, 3);
+    send_code(s, END_BLOCK, static_ltree);
+#ifdef ZLIB_DEBUG
+    s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
+#endif
+    bi_flush(s);
+}
+
+/* ===========================================================================
+ * Determine the best encoding for the current block: dynamic trees, static
+ * trees or store, and write out the encoded block.
+ */
+void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
+    deflate_state *s;
+    charf *buf;       /* input block, or NULL if too old */
+    ulg stored_len;   /* length of input block */
+    int last;         /* one if this is the last block for a file */
+{
+    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
+    int max_blindex = 0;  /* index of last bit length code of non zero freq */
+
+    /* Build the Huffman trees unless a stored block is forced */
+    if (s->level > 0) {
+
+        /* Check if the file is binary or text */
+        if (s->strm->data_type == Z_UNKNOWN)
+            s->strm->data_type = detect_data_type(s);
+
+        /* Construct the literal and distance trees */
+        build_tree(s, (tree_desc *)(&(s->l_desc)));
+        Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
+                s->static_len));
+
+        build_tree(s, (tree_desc *)(&(s->d_desc)));
+        Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
+                s->static_len));
+        /* At this point, opt_len and static_len are the total bit lengths of
+         * the compressed block data, excluding the tree representations.
+         */
+
+        /* Build the bit length tree for the above two trees, and get the index
+         * in bl_order of the last bit length code to send.
+         */
+        max_blindex = build_bl_tree(s);
+
+        /* Determine the best encoding. Compute the block lengths in bytes. */
+        opt_lenb = (s->opt_len+3+7)>>3;
+        static_lenb = (s->static_len+3+7)>>3;
+
+        Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
+                opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
+                s->last_lit));
+
+        if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
+
+    } else {
+        Assert(buf != (char*)0, "lost buf");
+        opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
+    }
+
+#ifdef FORCE_STORED
+    if (buf != (char*)0) { /* force stored block */
+#else
+    if (stored_len+4 <= opt_lenb && buf != (char*)0) {
+                       /* 4: two words for the lengths */
+#endif
+        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
+         * Otherwise we can't have processed more than WSIZE input bytes since
+         * the last block flush, because compression would have been
+         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
+         * transform a block into a stored block.
+         */
+        _tr_stored_block(s, buf, stored_len, last);
+
+#ifdef FORCE_STATIC
+    } else if (static_lenb >= 0) { /* force static trees */
+#else
+    } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
+#endif
+        send_bits(s, (STATIC_TREES<<1)+last, 3);
+        compress_block(s, (const ct_data *)static_ltree,
+                       (const ct_data *)static_dtree);
+#ifdef ZLIB_DEBUG
+        s->compressed_len += 3 + s->static_len;
+#endif
+    } else {
+        send_bits(s, (DYN_TREES<<1)+last, 3);
+        send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
+                       max_blindex+1);
+        compress_block(s, (const ct_data *)s->dyn_ltree,
+                       (const ct_data *)s->dyn_dtree);
+#ifdef ZLIB_DEBUG
+        s->compressed_len += 3 + s->opt_len;
+#endif
+    }
+    Assert (s->compressed_len == s->bits_sent, "bad compressed size");
+    /* The above check is made mod 2^32, for files larger than 512 MB
+     * and uLong implemented on 32 bits.
+     */
+    init_block(s);
+
+    if (last) {
+        bi_windup(s);
+#ifdef ZLIB_DEBUG
+        s->compressed_len += 7;  /* align on byte boundary */
+#endif
+    }
+    Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
+           s->compressed_len-7*last));
+}
+
+/* ===========================================================================
+ * Save the match info and tally the frequency counts. Return true if
+ * the current block must be flushed.
+ */
+int ZLIB_INTERNAL _tr_tally (s, dist, lc)
+    deflate_state *s;
+    unsigned dist;  /* distance of matched string */
+    unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
+{
+    s->d_buf[s->last_lit] = (ush)dist;
+    s->l_buf[s->last_lit++] = (uch)lc;
+    if (dist == 0) {
+        /* lc is the unmatched char */
+        s->dyn_ltree[lc].Freq++;
+    } else {
+        s->matches++;
+        /* Here, lc is the match length - MIN_MATCH */
+        dist--;             /* dist = match distance - 1 */
+        Assert((ush)dist < (ush)MAX_DIST(s) &&
+               (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
+               (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");
+
+        s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
+        s->dyn_dtree[d_code(dist)].Freq++;
+    }
+
+#ifdef TRUNCATE_BLOCK
+    /* Try to guess if it is profitable to stop the current block here */
+    if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
+        /* Compute an upper bound for the compressed length */
+        ulg out_length = (ulg)s->last_lit*8L;
+        ulg in_length = (ulg)((long)s->strstart - s->block_start);
+        int dcode;
+        for (dcode = 0; dcode < D_CODES; dcode++) {
+            out_length += (ulg)s->dyn_dtree[dcode].Freq *
+                (5L+extra_dbits[dcode]);
+        }
+        out_length >>= 3;
+        Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
+               s->last_lit, in_length, out_length,
+               100L - out_length*100L/in_length));
+        if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
+    }
+#endif
+    return (s->last_lit == s->lit_bufsize-1);
+    /* We avoid equality with lit_bufsize because of wraparound at 64K
+     * on 16 bit machines and because stored blocks are restricted to
+     * 64K-1 bytes.
+     */
+}
+
+/* ===========================================================================
+ * Send the block data compressed using the given Huffman trees
+ */
+local void compress_block(s, ltree, dtree)
+    deflate_state *s;
+    const ct_data *ltree; /* literal tree */
+    const ct_data *dtree; /* distance tree */
+{
+    unsigned dist;      /* distance of matched string */
+    int lc;             /* match length or unmatched char (if dist == 0) */
+    unsigned lx = 0;    /* running index in l_buf */
+    unsigned code;      /* the code to send */
+    int extra;          /* number of extra bits to send */
+
+    if (s->last_lit != 0) do {
+        dist = s->d_buf[lx];
+        lc = s->l_buf[lx++];
+        if (dist == 0) {
+            send_code(s, lc, ltree); /* send a literal byte */
+            Tracecv(isgraph(lc), (stderr," '%c' ", lc));
+        } else {
+            /* Here, lc is the match length - MIN_MATCH */
+            code = _length_code[lc];
+            send_code(s, code+LITERALS+1, ltree); /* send the length code */
+            extra = extra_lbits[code];
+            if (extra != 0) {
+                lc -= base_length[code];
+                send_bits(s, lc, extra);       /* send the extra length bits */
+            }
+            dist--; /* dist is now the match distance - 1 */
+            code = d_code(dist);
+            Assert (code < D_CODES, "bad d_code");
+
+            send_code(s, code, dtree);       /* send the distance code */
+            extra = extra_dbits[code];
+            if (extra != 0) {
+                dist -= (unsigned)base_dist[code];
+                send_bits(s, dist, extra);   /* send the extra distance bits */
+            }
+        } /* literal or match pair ? */
+
+        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
+        Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
+               "pendingBuf overflow");
+
+    } while (lx < s->last_lit);
+
+    send_code(s, END_BLOCK, ltree);
+}
+
+/* ===========================================================================
+ * Check if the data type is TEXT or BINARY, using the following algorithm:
+ * - TEXT if the two conditions below are satisfied:
+ *    a) There are no non-portable control characters belonging to the
+ *       "black list" (0..6, 14..25, 28..31).
+ *    b) There is at least one printable character belonging to the
+ *       "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
+ * - BINARY otherwise.
+ * - The following partially-portable control characters form a
+ *   "gray list" that is ignored in this detection algorithm:
+ *   (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
+ * IN assertion: the fields Freq of dyn_ltree are set.
+ */
+local int detect_data_type(s)
+    deflate_state *s;
+{
+    /* black_mask is the bit mask of black-listed bytes
+     * set bits 0..6, 14..25, and 28..31
+     * 0xf3ffc07f = binary 11110011111111111100000001111111
+     */
+    unsigned long black_mask = 0xf3ffc07fUL;
+    int n;
+
+    /* Check for non-textual ("black-listed") bytes. */
+    for (n = 0; n <= 31; n++, black_mask >>= 1)
+        if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
+            return Z_BINARY;
+
+    /* Check for textual ("white-listed") bytes. */
+    if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
+            || s->dyn_ltree[13].Freq != 0)
+        return Z_TEXT;
+    for (n = 32; n < LITERALS; n++)
+        if (s->dyn_ltree[n].Freq != 0)
+            return Z_TEXT;
+
+    /* There are no "black-listed" or "white-listed" bytes:
+     * this stream either is empty or has tolerated ("gray-listed") bytes only.
+     */
+    return Z_BINARY;
+}
+
+/* ===========================================================================
+ * Reverse the first len bits of a code, using straightforward code (a faster
+ * method would use a table)
+ * IN assertion: 1 <= len <= 15
+ */
+local unsigned bi_reverse(code, len)
+    unsigned code; /* the value to invert */
+    int len;       /* its bit length */
+{
+    register unsigned res = 0;
+    do {
+        res |= code & 1;
+        code >>= 1, res <<= 1;
+    } while (--len > 0);
+    return res >> 1;
+}
+
+/* ===========================================================================
+ * Flush the bit buffer, keeping at most 7 bits in it.
+ */
+local void bi_flush(s)
+    deflate_state *s;
+{
+    if (s->bi_valid == 16) {
+        put_short(s, s->bi_buf);
+        s->bi_buf = 0;
+        s->bi_valid = 0;
+    } else if (s->bi_valid >= 8) {
+        put_byte(s, (Byte)s->bi_buf);
+        s->bi_buf >>= 8;
+        s->bi_valid -= 8;
+    }
+}
+
+/* ===========================================================================
+ * Flush the bit buffer and align the output on a byte boundary
+ */
+local void bi_windup(s)
+    deflate_state *s;
+{
+    if (s->bi_valid > 8) {
+        put_short(s, s->bi_buf);
+    } else if (s->bi_valid > 0) {
+        put_byte(s, (Byte)s->bi_buf);
+    }
+    s->bi_buf = 0;
+    s->bi_valid = 0;
+#ifdef ZLIB_DEBUG
+    s->bits_sent = (s->bits_sent+7) & ~7;
+#endif
+}
diff --git a/xs/src/png/zlib/trees.h b/xs/src/png/zlib/trees.h
new file mode 100644
index 000000000..d35639d82
--- /dev/null
+++ b/xs/src/png/zlib/trees.h
@@ -0,0 +1,128 @@
+/* header created automatically with -DGEN_TREES_H */
+
+local const ct_data static_ltree[L_CODES+2] = {
+{{ 12},{  8}}, {{140},{  8}}, {{ 76},{  8}}, {{204},{  8}}, {{ 44},{  8}},
+{{172},{  8}}, {{108},{  8}}, {{236},{  8}}, {{ 28},{  8}}, {{156},{  8}},
+{{ 92},{  8}}, {{220},{  8}}, {{ 60},{  8}}, {{188},{  8}}, {{124},{  8}},
+{{252},{  8}}, {{  2},{  8}}, {{130},{  8}}, {{ 66},{  8}}, {{194},{  8}},
+{{ 34},{  8}}, {{162},{  8}}, {{ 98},{  8}}, {{226},{  8}}, {{ 18},{  8}},
+{{146},{  8}}, {{ 82},{  8}}, {{210},{  8}}, {{ 50},{  8}}, {{178},{  8}},
+{{114},{  8}}, {{242},{  8}}, {{ 10},{  8}}, {{138},{  8}}, {{ 74},{  8}},
+{{202},{  8}}, {{ 42},{  8}}, {{170},{  8}}, {{106},{  8}}, {{234},{  8}},
+{{ 26},{  8}}, {{154},{  8}}, {{ 90},{  8}}, {{218},{  8}}, {{ 58},{  8}},
+{{186},{  8}}, {{122},{  8}}, {{250},{  8}}, {{  6},{  8}}, {{134},{  8}},
+{{ 70},{  8}}, {{198},{  8}}, {{ 38},{  8}}, {{166},{  8}}, {{102},{  8}},
+{{230},{  8}}, {{ 22},{  8}}, {{150},{  8}}, {{ 86},{  8}}, {{214},{  8}},
+{{ 54},{  8}}, {{182},{  8}}, {{118},{  8}}, {{246},{  8}}, {{ 14},{  8}},
+{{142},{  8}}, {{ 78},{  8}}, {{206},{  8}}, {{ 46},{  8}}, {{174},{  8}},
+{{110},{  8}}, {{238},{  8}}, {{ 30},{  8}}, {{158},{  8}}, {{ 94},{  8}},
+{{222},{  8}}, {{ 62},{  8}}, {{190},{  8}}, {{126},{  8}}, {{254},{  8}},
+{{  1},{  8}}, {{129},{  8}}, {{ 65},{  8}}, {{193},{  8}}, {{ 33},{  8}},
+{{161},{  8}}, {{ 97},{  8}}, {{225},{  8}}, {{ 17},{  8}}, {{145},{  8}},
+{{ 81},{  8}}, {{209},{  8}}, {{ 49},{  8}}, {{177},{  8}}, {{113},{  8}},
+{{241},{  8}}, {{  9},{  8}}, {{137},{  8}}, {{ 73},{  8}}, {{201},{  8}},
+{{ 41},{  8}}, {{169},{  8}}, {{105},{  8}}, {{233},{  8}}, {{ 25},{  8}},
+{{153},{  8}}, {{ 89},{  8}}, {{217},{  8}}, {{ 57},{  8}}, {{185},{  8}},
+{{121},{  8}}, {{249},{  8}}, {{  5},{  8}}, {{133},{  8}}, {{ 69},{  8}},
+{{197},{  8}}, {{ 37},{  8}}, {{165},{  8}}, {{101},{  8}}, {{229},{  8}},
+{{ 21},{  8}}, {{149},{  8}}, {{ 85},{  8}}, {{213},{  8}}, {{ 53},{  8}},
+{{181},{  8}}, {{117},{  8}}, {{245},{  8}}, {{ 13},{  8}}, {{141},{  8}},
+{{ 77},{  8}}, {{205},{  8}}, {{ 45},{  8}}, {{173},{  8}}, {{109},{  8}},
+{{237},{  8}}, {{ 29},{  8}}, {{157},{  8}}, {{ 93},{  8}}, {{221},{  8}},
+{{ 61},{  8}}, {{189},{  8}}, {{125},{  8}}, {{253},{  8}}, {{ 19},{  9}},
+{{275},{  9}}, {{147},{  9}}, {{403},{  9}}, {{ 83},{  9}}, {{339},{  9}},
+{{211},{  9}}, {{467},{  9}}, {{ 51},{  9}}, {{307},{  9}}, {{179},{  9}},
+{{435},{  9}}, {{115},{  9}}, {{371},{  9}}, {{243},{  9}}, {{499},{  9}},
+{{ 11},{  9}}, {{267},{  9}}, {{139},{  9}}, {{395},{  9}}, {{ 75},{  9}},
+{{331},{  9}}, {{203},{  9}}, {{459},{  9}}, {{ 43},{  9}}, {{299},{  9}},
+{{171},{  9}}, {{427},{  9}}, {{107},{  9}}, {{363},{  9}}, {{235},{  9}},
+{{491},{  9}}, {{ 27},{  9}}, {{283},{  9}}, {{155},{  9}}, {{411},{  9}},
+{{ 91},{  9}}, {{347},{  9}}, {{219},{  9}}, {{475},{  9}}, {{ 59},{  9}},
+{{315},{  9}}, {{187},{  9}}, {{443},{  9}}, {{123},{  9}}, {{379},{  9}},
+{{251},{  9}}, {{507},{  9}}, {{  7},{  9}}, {{263},{  9}}, {{135},{  9}},
+{{391},{  9}}, {{ 71},{  9}}, {{327},{  9}}, {{199},{  9}}, {{455},{  9}},
+{{ 39},{  9}}, {{295},{  9}}, {{167},{  9}}, {{423},{  9}}, {{103},{  9}},
+{{359},{  9}}, {{231},{  9}}, {{487},{  9}}, {{ 23},{  9}}, {{279},{  9}},
+{{151},{  9}}, {{407},{  9}}, {{ 87},{  9}}, {{343},{  9}}, {{215},{  9}},
+{{471},{  9}}, {{ 55},{  9}}, {{311},{  9}}, {{183},{  9}}, {{439},{  9}},
+{{119},{  9}}, {{375},{  9}}, {{247},{  9}}, {{503},{  9}}, {{ 15},{  9}},
+{{271},{  9}}, {{143},{  9}}, {{399},{  9}}, {{ 79},{  9}}, {{335},{  9}},
+{{207},{  9}}, {{463},{  9}}, {{ 47},{  9}}, {{303},{  9}}, {{175},{  9}},
+{{431},{  9}}, {{111},{  9}}, {{367},{  9}}, {{239},{  9}}, {{495},{  9}},
+{{ 31},{  9}}, {{287},{  9}}, {{159},{  9}}, {{415},{  9}}, {{ 95},{  9}},
+{{351},{  9}}, {{223},{  9}}, {{479},{  9}}, {{ 63},{  9}}, {{319},{  9}},
+{{191},{  9}}, {{447},{  9}}, {{127},{  9}}, {{383},{  9}}, {{255},{  9}},
+{{511},{  9}}, {{  0},{  7}}, {{ 64},{  7}}, {{ 32},{  7}}, {{ 96},{  7}},
+{{ 16},{  7}}, {{ 80},{  7}}, {{ 48},{  7}}, {{112},{  7}}, {{  8},{  7}},
+{{ 72},{  7}}, {{ 40},{  7}}, {{104},{  7}}, {{ 24},{  7}}, {{ 88},{  7}},
+{{ 56},{  7}}, {{120},{  7}}, {{  4},{  7}}, {{ 68},{  7}}, {{ 36},{  7}},
+{{100},{  7}}, {{ 20},{  7}}, {{ 84},{  7}}, {{ 52},{  7}}, {{116},{  7}},
+{{  3},{  8}}, {{131},{  8}}, {{ 67},{  8}}, {{195},{  8}}, {{ 35},{  8}},
+{{163},{  8}}, {{ 99},{  8}}, {{227},{  8}}
+};
+
+local const ct_data static_dtree[D_CODES] = {
+{{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
+{{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
+{{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
+{{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
+{{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
+{{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
+};
+
+const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {
+ 0,  1,  2,  3,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  8,
+ 8,  8,  8,  8,  9,  9,  9,  9,  9,  9,  9,  9, 10, 10, 10, 10, 10, 10, 10, 10,
+10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
+11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
+13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
+13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
+14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
+15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  0,  0, 16, 17,
+18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
+23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
+27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
+};
+
+const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {
+ 0,  1,  2,  3,  4,  5,  6,  7,  8,  8,  9,  9, 10, 10, 11, 11, 12, 12, 12, 12,
+13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
+17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
+19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
+21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
+22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
+23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
+26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
+};
+
+local const int base_length[LENGTH_CODES] = {
+0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
+64, 80, 96, 112, 128, 160, 192, 224, 0
+};
+
+local const int base_dist[D_CODES] = {
+    0,     1,     2,     3,     4,     6,     8,    12,    16,    24,
+   32,    48,    64,    96,   128,   192,   256,   384,   512,   768,
+ 1024,  1536,  2048,  3072,  4096,  6144,  8192, 12288, 16384, 24576
+};
+
diff --git a/xs/src/png/zlib/uncompr.c b/xs/src/png/zlib/uncompr.c
new file mode 100644
index 000000000..f03a1a865
--- /dev/null
+++ b/xs/src/png/zlib/uncompr.c
@@ -0,0 +1,93 @@
+/* uncompr.c -- decompress a memory buffer
+ * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#define ZLIB_INTERNAL
+#include "zlib.h"
+
+/* ===========================================================================
+     Decompresses the source buffer into the destination buffer.  *sourceLen is
+   the byte length of the source buffer. Upon entry, *destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data. (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit,
+   *destLen is the size of the decompressed data and *sourceLen is the number
+   of source bytes consumed. Upon return, source + *sourceLen points to the
+   first unused input byte.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
+   Z_DATA_ERROR if the input data was corrupted, including if the input data is
+   an incomplete zlib stream.
+*/
+int ZEXPORT uncompress2 (dest, destLen, source, sourceLen)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong *sourceLen;
+{
+    z_stream stream;
+    int err;
+    const uInt max = (uInt)-1;
+    uLong len, left;
+    Byte buf[1];    /* for detection of incomplete stream when *destLen == 0 */
+
+    len = *sourceLen;
+    if (*destLen) {
+        left = *destLen;
+        *destLen = 0;
+    }
+    else {
+        left = 1;
+        dest = buf;
+    }
+
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
+    stream.zalloc = (alloc_func)0;
+    stream.zfree = (free_func)0;
+    stream.opaque = (voidpf)0;
+
+    err = inflateInit(&stream);
+    if (err != Z_OK) return err;
+
+    stream.next_out = dest;
+    stream.avail_out = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = len > (uLong)max ? max : (uInt)len;
+            len -= stream.avail_in;
+        }
+        err = inflate(&stream, Z_NO_FLUSH);
+    } while (err == Z_OK);
+
+    *sourceLen -= len + stream.avail_in;
+    if (dest != buf)
+        *destLen = stream.total_out;
+    else if (stream.total_out && err == Z_BUF_ERROR)
+        left = 1;
+
+    inflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK :
+           err == Z_NEED_DICT ? Z_DATA_ERROR  :
+           err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
+           err;
+}
+
+int ZEXPORT uncompress (dest, destLen, source, sourceLen)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong sourceLen;
+{
+    return uncompress2(dest, destLen, source, &sourceLen);
+}
diff --git a/xs/src/png/zlib/watcom/watcom_f.mak b/xs/src/png/zlib/watcom/watcom_f.mak
new file mode 100644
index 000000000..37f4d74c1
--- /dev/null
+++ b/xs/src/png/zlib/watcom/watcom_f.mak
@@ -0,0 +1,43 @@
+# Makefile for zlib
+# OpenWatcom flat model
+# Last updated: 28-Dec-2005
+
+# To use, do "wmake -f watcom_f.mak"
+
+C_SOURCE =  adler32.c  compress.c crc32.c   deflate.c    &
+	    gzclose.c  gzlib.c    gzread.c  gzwrite.c    &
+            infback.c  inffast.c  inflate.c inftrees.c   &
+            trees.c    uncompr.c  zutil.c
+
+OBJS =      adler32.obj  compress.obj crc32.obj   deflate.obj    &
+	    gzclose.obj  gzlib.obj    gzread.obj  gzwrite.obj    &
+            infback.obj  inffast.obj  inflate.obj inftrees.obj   &
+            trees.obj    uncompr.obj  zutil.obj
+
+CC       = wcc386
+LINKER   = wcl386
+CFLAGS   = -zq -mf -3r -fp3 -s -bt=dos -oilrtfm -fr=nul -wx
+ZLIB_LIB = zlib_f.lib
+
+.C.OBJ:
+        $(CC) $(CFLAGS) $[@
+
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+$(ZLIB_LIB): $(OBJS)
+	wlib -b -c $(ZLIB_LIB) -+adler32.obj  -+compress.obj -+crc32.obj
+	wlib -b -c $(ZLIB_LIB) -+gzclose.obj  -+gzlib.obj    -+gzread.obj   -+gzwrite.obj
+        wlib -b -c $(ZLIB_LIB) -+deflate.obj  -+infback.obj
+        wlib -b -c $(ZLIB_LIB) -+inffast.obj  -+inflate.obj  -+inftrees.obj
+        wlib -b -c $(ZLIB_LIB) -+trees.obj    -+uncompr.obj  -+zutil.obj
+
+example.exe: $(ZLIB_LIB) example.obj
+	$(LINKER) -ldos32a -fe=example.exe example.obj $(ZLIB_LIB)
+
+minigzip.exe: $(ZLIB_LIB) minigzip.obj
+	$(LINKER) -ldos32a -fe=minigzip.exe minigzip.obj $(ZLIB_LIB)
+
+clean: .SYMBOLIC
+          del *.obj
+          del $(ZLIB_LIB)
+          @echo Cleaning done
diff --git a/xs/src/png/zlib/watcom/watcom_l.mak b/xs/src/png/zlib/watcom/watcom_l.mak
new file mode 100644
index 000000000..193eed7b3
--- /dev/null
+++ b/xs/src/png/zlib/watcom/watcom_l.mak
@@ -0,0 +1,43 @@
+# Makefile for zlib
+# OpenWatcom large model
+# Last updated: 28-Dec-2005
+
+# To use, do "wmake -f watcom_l.mak"
+
+C_SOURCE =  adler32.c  compress.c crc32.c   deflate.c    &
+	    gzclose.c  gzlib.c    gzread.c  gzwrite.c    &
+            infback.c  inffast.c  inflate.c inftrees.c   &
+            trees.c    uncompr.c  zutil.c
+
+OBJS =      adler32.obj  compress.obj crc32.obj   deflate.obj    &
+	    gzclose.obj  gzlib.obj    gzread.obj  gzwrite.obj    &
+            infback.obj  inffast.obj  inflate.obj inftrees.obj   &
+            trees.obj    uncompr.obj  zutil.obj
+
+CC       = wcc
+LINKER   = wcl
+CFLAGS   = -zq -ml -s -bt=dos -oilrtfm -fr=nul -wx
+ZLIB_LIB = zlib_l.lib
+
+.C.OBJ:
+        $(CC) $(CFLAGS) $[@
+
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+$(ZLIB_LIB): $(OBJS)
+	wlib -b -c $(ZLIB_LIB) -+adler32.obj  -+compress.obj -+crc32.obj
+	wlib -b -c $(ZLIB_LIB) -+gzclose.obj  -+gzlib.obj    -+gzread.obj   -+gzwrite.obj
+        wlib -b -c $(ZLIB_LIB) -+deflate.obj  -+infback.obj
+        wlib -b -c $(ZLIB_LIB) -+inffast.obj  -+inflate.obj  -+inftrees.obj
+        wlib -b -c $(ZLIB_LIB) -+trees.obj    -+uncompr.obj  -+zutil.obj
+
+example.exe: $(ZLIB_LIB) example.obj
+	$(LINKER) -fe=example.exe example.obj $(ZLIB_LIB)
+
+minigzip.exe: $(ZLIB_LIB) minigzip.obj
+	$(LINKER) -fe=minigzip.exe minigzip.obj $(ZLIB_LIB)
+
+clean: .SYMBOLIC
+          del *.obj
+          del $(ZLIB_LIB)
+          @echo Cleaning done
diff --git a/xs/src/png/zlib/win32/DLL_FAQ.txt b/xs/src/png/zlib/win32/DLL_FAQ.txt
new file mode 100644
index 000000000..12c009018
--- /dev/null
+++ b/xs/src/png/zlib/win32/DLL_FAQ.txt
@@ -0,0 +1,397 @@
+
+            Frequently Asked Questions about ZLIB1.DLL
+
+
+This document describes the design, the rationale, and the usage
+of the official DLL build of zlib, named ZLIB1.DLL.  If you have
+general questions about zlib, you should see the file "FAQ" found
+in the zlib distribution, or at the following location:
+  http://www.gzip.org/zlib/zlib_faq.html
+
+
+ 1. What is ZLIB1.DLL, and how can I get it?
+
+  - ZLIB1.DLL is the official build of zlib as a DLL.
+    (Please remark the character '1' in the name.)
+
+    Pointers to a precompiled ZLIB1.DLL can be found in the zlib
+    web site at:
+      http://www.zlib.net/
+
+    Applications that link to ZLIB1.DLL can rely on the following
+    specification:
+
+    * The exported symbols are exclusively defined in the source
+      files "zlib.h" and "zlib.def", found in an official zlib
+      source distribution.
+    * The symbols are exported by name, not by ordinal.
+    * The exported names are undecorated.
+    * The calling convention of functions is "C" (CDECL).
+    * The ZLIB1.DLL binary is linked to MSVCRT.DLL.
+
+    The archive in which ZLIB1.DLL is bundled contains compiled
+    test programs that must run with a valid build of ZLIB1.DLL.
+    It is recommended to download the prebuilt DLL from the zlib
+    web site, instead of building it yourself, to avoid potential
+    incompatibilities that could be introduced by your compiler
+    and build settings.  If you do build the DLL yourself, please
+    make sure that it complies with all the above requirements,
+    and it runs with the precompiled test programs, bundled with
+    the original ZLIB1.DLL distribution.
+
+    If, for any reason, you need to build an incompatible DLL,
+    please use a different file name.
+
+
+ 2. Why did you change the name of the DLL to ZLIB1.DLL?
+    What happened to the old ZLIB.DLL?
+
+  - The old ZLIB.DLL, built from zlib-1.1.4 or earlier, required
+    compilation settings that were incompatible to those used by
+    a static build.  The DLL settings were supposed to be enabled
+    by defining the macro ZLIB_DLL, before including "zlib.h".
+    Incorrect handling of this macro was silently accepted at
+    build time, resulting in two major problems:
+
+    * ZLIB_DLL was missing from the old makefile.  When building
+      the DLL, not all people added it to the build options.  In
+      consequence, incompatible incarnations of ZLIB.DLL started
+      to circulate around the net.
+
+    * When switching from using the static library to using the
+      DLL, applications had to define the ZLIB_DLL macro and
+      to recompile all the sources that contained calls to zlib
+      functions.  Failure to do so resulted in creating binaries
+      that were unable to run with the official ZLIB.DLL build.
+
+    The only possible solution that we could foresee was to make
+    a binary-incompatible change in the DLL interface, in order to
+    remove the dependency on the ZLIB_DLL macro, and to release
+    the new DLL under a different name.
+
+    We chose the name ZLIB1.DLL, where '1' indicates the major
+    zlib version number.  We hope that we will not have to break
+    the binary compatibility again, at least not as long as the
+    zlib-1.x series will last.
+
+    There is still a ZLIB_DLL macro, that can trigger a more
+    efficient build and use of the DLL, but compatibility no
+    longer dependents on it.
+
+
+ 3. Can I build ZLIB.DLL from the new zlib sources, and replace
+    an old ZLIB.DLL, that was built from zlib-1.1.4 or earlier?
+
+  - In principle, you can do it by assigning calling convention
+    keywords to the macros ZEXPORT and ZEXPORTVA.  In practice,
+    it depends on what you mean by "an old ZLIB.DLL", because the
+    old DLL exists in several mutually-incompatible versions.
+    You have to find out first what kind of calling convention is
+    being used in your particular ZLIB.DLL build, and to use the
+    same one in the new build.  If you don't know what this is all
+    about, you might be better off if you would just leave the old
+    DLL intact.
+
+
+ 4. Can I compile my application using the new zlib interface, and
+    link it to an old ZLIB.DLL, that was built from zlib-1.1.4 or
+    earlier?
+
+  - The official answer is "no"; the real answer depends again on
+    what kind of ZLIB.DLL you have.  Even if you are lucky, this
+    course of action is unreliable.
+
+    If you rebuild your application and you intend to use a newer
+    version of zlib (post- 1.1.4), it is strongly recommended to
+    link it to the new ZLIB1.DLL.
+
+
+ 5. Why are the zlib symbols exported by name, and not by ordinal?
+
+  - Although exporting symbols by ordinal is a little faster, it
+    is risky.  Any single glitch in the maintenance or use of the
+    DEF file that contains the ordinals can result in incompatible
+    builds and frustrating crashes.  Simply put, the benefits of
+    exporting symbols by ordinal do not justify the risks.
+
+    Technically, it should be possible to maintain ordinals in
+    the DEF file, and still export the symbols by name.  Ordinals
+    exist in every DLL, and even if the dynamic linking performed
+    at the DLL startup is searching for names, ordinals serve as
+    hints, for a faster name lookup.  However, if the DEF file
+    contains ordinals, the Microsoft linker automatically builds
+    an implib that will cause the executables linked to it to use
+    those ordinals, and not the names.  It is interesting to
+    notice that the GNU linker for Win32 does not suffer from this
+    problem.
+
+    It is possible to avoid the DEF file if the exported symbols
+    are accompanied by a "__declspec(dllexport)" attribute in the
+    source files.  You can do this in zlib by predefining the
+    ZLIB_DLL macro.
+
+
+ 6. I see that the ZLIB1.DLL functions use the "C" (CDECL) calling
+    convention.  Why not use the STDCALL convention?
+    STDCALL is the standard convention in Win32, and I need it in
+    my Visual Basic project!
+
+    (For readability, we use CDECL to refer to the convention
+     triggered by the "__cdecl" keyword, STDCALL to refer to
+     the convention triggered by "__stdcall", and FASTCALL to
+     refer to the convention triggered by "__fastcall".)
+
+  - Most of the native Windows API functions (without varargs) use
+    indeed the WINAPI convention (which translates to STDCALL in
+    Win32), but the standard C functions use CDECL.  If a user
+    application is intrinsically tied to the Windows API (e.g.
+    it calls native Windows API functions such as CreateFile()),
+    sometimes it makes sense to decorate its own functions with
+    WINAPI.  But if ANSI C or POSIX portability is a goal (e.g.
+    it calls standard C functions such as fopen()), it is not a
+    sound decision to request the inclusion of <windows.h>, or to
+    use non-ANSI constructs, for the sole purpose to make the user
+    functions STDCALL-able.
+
+    The functionality offered by zlib is not in the category of
+    "Windows functionality", but is more like "C functionality".
+
+    Technically, STDCALL is not bad; in fact, it is slightly
+    faster than CDECL, and it works with variable-argument
+    functions, just like CDECL.  It is unfortunate that, in spite
+    of using STDCALL in the Windows API, it is not the default
+    convention used by the C compilers that run under Windows.
+    The roots of the problem reside deep inside the unsafety of
+    the K&R-style function prototypes, where the argument types
+    are not specified; but that is another story for another day.
+
+    The remaining fact is that CDECL is the default convention.
+    Even if an explicit convention is hard-coded into the function
+    prototypes inside C headers, problems may appear.  The
+    necessity to expose the convention in users' callbacks is one
+    of these problems.
+
+    The calling convention issues are also important when using
+    zlib in other programming languages.  Some of them, like Ada
+    (GNAT) and Fortran (GNU G77), have C bindings implemented
+    initially on Unix, and relying on the C calling convention.
+    On the other hand, the pre- .NET versions of Microsoft Visual
+    Basic require STDCALL, while Borland Delphi prefers, although
+    it does not require, FASTCALL.
+
+    In fairness to all possible uses of zlib outside the C
+    programming language, we choose the default "C" convention.
+    Anyone interested in different bindings or conventions is
+    encouraged to maintain specialized projects.  The "contrib/"
+    directory from the zlib distribution already holds a couple
+    of foreign bindings, such as Ada, C++, and Delphi.
+
+
+ 7. I need a DLL for my Visual Basic project.  What can I do?
+
+  - Define the ZLIB_WINAPI macro before including "zlib.h", when
+    building both the DLL and the user application (except that
+    you don't need to define anything when using the DLL in Visual
+    Basic).  The ZLIB_WINAPI macro will switch on the WINAPI
+    (STDCALL) convention.  The name of this DLL must be different
+    than the official ZLIB1.DLL.
+
+    Gilles Vollant has contributed a build named ZLIBWAPI.DLL,
+    with the ZLIB_WINAPI macro turned on, and with the minizip
+    functionality built in.  For more information, please read
+    the notes inside "contrib/vstudio/readme.txt", found in the
+    zlib distribution.
+
+
+ 8. I need to use zlib in my Microsoft .NET project.  What can I
+    do?
+
+  - Henrik Ravn has contributed a .NET wrapper around zlib.  Look
+    into contrib/dotzlib/, inside the zlib distribution.
+
+
+ 9. If my application uses ZLIB1.DLL, should I link it to
+    MSVCRT.DLL?  Why?
+
+  - It is not required, but it is recommended to link your
+    application to MSVCRT.DLL, if it uses ZLIB1.DLL.
+
+    The executables (.EXE, .DLL, etc.) that are involved in the
+    same process and are using the C run-time library (i.e. they
+    are calling standard C functions), must link to the same
+    library.  There are several libraries in the Win32 system:
+    CRTDLL.DLL, MSVCRT.DLL, the static C libraries, etc.
+    Since ZLIB1.DLL is linked to MSVCRT.DLL, the executables that
+    depend on it should also be linked to MSVCRT.DLL.
+
+
+10. Why are you saying that ZLIB1.DLL and my application should
+    be linked to the same C run-time (CRT) library?  I linked my
+    application and my DLLs to different C libraries (e.g. my
+    application to a static library, and my DLLs to MSVCRT.DLL),
+    and everything works fine.
+
+  - If a user library invokes only pure Win32 API (accessible via
+    <windows.h> and the related headers), its DLL build will work
+    in any context.  But if this library invokes standard C API,
+    things get more complicated.
+
+    There is a single Win32 library in a Win32 system.  Every
+    function in this library resides in a single DLL module, that
+    is safe to call from anywhere.  On the other hand, there are
+    multiple versions of the C library, and each of them has its
+    own separate internal state.  Standalone executables and user
+    DLLs that call standard C functions must link to a C run-time
+    (CRT) library, be it static or shared (DLL).  Intermixing
+    occurs when an executable (not necessarily standalone) and a
+    DLL are linked to different CRTs, and both are running in the
+    same process.
+
+    Intermixing multiple CRTs is possible, as long as their
+    internal states are kept intact.  The Microsoft Knowledge Base
+    articles KB94248 "HOWTO: Use the C Run-Time" and KB140584
+    "HOWTO: Link with the Correct C Run-Time (CRT) Library"
+    mention the potential problems raised by intermixing.
+
+    If intermixing works for you, it's because your application
+    and DLLs are avoiding the corruption of each of the CRTs'
+    internal states, maybe by careful design, or maybe by fortune.
+
+    Also note that linking ZLIB1.DLL to non-Microsoft CRTs, such
+    as those provided by Borland, raises similar problems.
+
+
+11. Why are you linking ZLIB1.DLL to MSVCRT.DLL?
+
+  - MSVCRT.DLL exists on every Windows 95 with a new service pack
+    installed, or with Microsoft Internet Explorer 4 or later, and
+    on all other Windows 4.x or later (Windows 98, Windows NT 4,
+    or later).  It is freely distributable; if not present in the
+    system, it can be downloaded from Microsoft or from other
+    software provider for free.
+
+    The fact that MSVCRT.DLL does not exist on a virgin Windows 95
+    is not so problematic.  Windows 95 is scarcely found nowadays,
+    Microsoft ended its support a long time ago, and many recent
+    applications from various vendors, including Microsoft, do not
+    even run on it.  Furthermore, no serious user should run
+    Windows 95 without a proper update installed.
+
+
+12. Why are you not linking ZLIB1.DLL to
+    <<my favorite C run-time library>> ?
+
+  - We considered and abandoned the following alternatives:
+
+    * Linking ZLIB1.DLL to a static C library (LIBC.LIB, or
+      LIBCMT.LIB) is not a good option.  People are using the DLL
+      mainly to save disk space.  If you are linking your program
+      to a static C library, you may as well consider linking zlib
+      in statically, too.
+
+    * Linking ZLIB1.DLL to CRTDLL.DLL looks appealing, because
+      CRTDLL.DLL is present on every Win32 installation.
+      Unfortunately, it has a series of problems: it does not
+      work properly with Microsoft's C++ libraries, it does not
+      provide support for 64-bit file offsets, (and so on...),
+      and Microsoft discontinued its support a long time ago.
+
+    * Linking ZLIB1.DLL to MSVCR70.DLL or MSVCR71.DLL, supplied
+      with the Microsoft .NET platform, and Visual C++ 7.0/7.1,
+      raises problems related to the status of ZLIB1.DLL as a
+      system component.  According to the Microsoft Knowledge Base
+      article KB326922 "INFO: Redistribution of the Shared C
+      Runtime Component in Visual C++ .NET", MSVCR70.DLL and
+      MSVCR71.DLL are not supposed to function as system DLLs,
+      because they may clash with MSVCRT.DLL.  Instead, the
+      application's installer is supposed to put these DLLs
+      (if needed) in the application's private directory.
+      If ZLIB1.DLL depends on a non-system runtime, it cannot
+      function as a redistributable system component.
+
+    * Linking ZLIB1.DLL to non-Microsoft runtimes, such as
+      Borland's, or Cygwin's, raises problems related to the
+      reliable presence of these runtimes on Win32 systems.
+      It's easier to let the DLL build of zlib up to the people
+      who distribute these runtimes, and who may proceed as
+      explained in the answer to Question 14.
+
+
+13. If ZLIB1.DLL cannot be linked to MSVCR70.DLL or MSVCR71.DLL,
+    how can I build/use ZLIB1.DLL in Microsoft Visual C++ 7.0
+    (Visual Studio .NET) or newer?
+
+  - Due to the problems explained in the Microsoft Knowledge Base
+    article KB326922 (see the previous answer), the C runtime that
+    comes with the VC7 environment is no longer considered a
+    system component.  That is, it should not be assumed that this
+    runtime exists, or may be installed in a system directory.
+    Since ZLIB1.DLL is supposed to be a system component, it may
+    not depend on a non-system component.
+
+    In order to link ZLIB1.DLL and your application to MSVCRT.DLL
+    in VC7, you need the library of Visual C++ 6.0 or older.  If
+    you don't have this library at hand, it's probably best not to
+    use ZLIB1.DLL.
+
+    We are hoping that, in the future, Microsoft will provide a
+    way to build applications linked to a proper system runtime,
+    from the Visual C++ environment.  Until then, you have a
+    couple of alternatives, such as linking zlib in statically.
+    If your application requires dynamic linking, you may proceed
+    as explained in the answer to Question 14.
+
+
+14. I need to link my own DLL build to a CRT different than
+    MSVCRT.DLL.  What can I do?
+
+  - Feel free to rebuild the DLL from the zlib sources, and link
+    it the way you want.  You should, however, clearly state that
+    your build is unofficial.  You should give it a different file
+    name, and/or install it in a private directory that can be
+    accessed by your application only, and is not visible to the
+    others (i.e. it's neither in the PATH, nor in the SYSTEM or
+    SYSTEM32 directories).  Otherwise, your build may clash with
+    applications that link to the official build.
+
+    For example, in Cygwin, zlib is linked to the Cygwin runtime
+    CYGWIN1.DLL, and it is distributed under the name CYGZ.DLL.
+
+
+15. May I include additional pieces of code that I find useful,
+    link them in ZLIB1.DLL, and export them?
+
+  - No.  A legitimate build of ZLIB1.DLL must not include code
+    that does not originate from the official zlib source code.
+    But you can make your own private DLL build, under a different
+    file name, as suggested in the previous answer.
+
+    For example, zlib is a part of the VCL library, distributed
+    with Borland Delphi and C++ Builder.  The DLL build of VCL
+    is a redistributable file, named VCLxx.DLL.
+
+
+16. May I remove some functionality out of ZLIB1.DLL, by enabling
+    macros like NO_GZCOMPRESS or NO_GZIP at compile time?
+
+  - No.  A legitimate build of ZLIB1.DLL must provide the complete
+    zlib functionality, as implemented in the official zlib source
+    code.  But you can make your own private DLL build, under a
+    different file name, as suggested in the previous answer.
+
+
+17. I made my own ZLIB1.DLL build.  Can I test it for compliance?
+
+  - We prefer that you download the official DLL from the zlib
+    web site.  If you need something peculiar from this DLL, you
+    can send your suggestion to the zlib mailing list.
+
+    However, in case you do rebuild the DLL yourself, you can run
+    it with the test programs found in the DLL distribution.
+    Running these test programs is not a guarantee of compliance,
+    but a failure can imply a detected problem.
+
+**
+
+This document is written and maintained by
+Cosmin Truta <cosmint@cs.ubbcluj.ro>
diff --git a/xs/src/png/zlib/win32/Makefile.bor b/xs/src/png/zlib/win32/Makefile.bor
new file mode 100644
index 000000000..d152bbb7f
--- /dev/null
+++ b/xs/src/png/zlib/win32/Makefile.bor
@@ -0,0 +1,110 @@
+# Makefile for zlib
+# Borland C++ for Win32
+#
+# Usage:
+#  make -f win32/Makefile.bor
+#  make -f win32/Makefile.bor LOCAL_ZLIB=-DASMV OBJA=match.obj OBJPA=+match.obj
+
+# ------------ Borland C++ ------------
+
+# Optional nonstandard preprocessor flags (e.g. -DMAX_MEM_LEVEL=7)
+# should be added to the environment via "set LOCAL_ZLIB=-DFOO" or
+# added to the declaration of LOC here:
+LOC = $(LOCAL_ZLIB)
+
+CC = bcc32
+AS = bcc32
+LD = bcc32
+AR = tlib
+CFLAGS  = -a -d -k- -O2 $(LOC)
+ASFLAGS = $(LOC)
+LDFLAGS = $(LOC)
+
+
+# variables
+ZLIB_LIB = zlib.lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+#OBJA =
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+#OBJPA=
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $<
+
+.asm.obj:
+	$(AS) -c $(ASFLAGS) $<
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# For the sake of the old Borland make,
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2) $(OBJA)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+	$(AR) $(ZLIB_LIB) $(OBJPA)
+
+
+# testing
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+
+# cleanup
+clean:
+	-del $(ZLIB_LIB)
+	-del *.obj
+	-del *.exe
+	-del *.tds
+	-del zlib.bak
+	-del foo.gz
diff --git a/xs/src/png/zlib/win32/Makefile.gcc b/xs/src/png/zlib/win32/Makefile.gcc
new file mode 100644
index 000000000..305be50af
--- /dev/null
+++ b/xs/src/png/zlib/win32/Makefile.gcc
@@ -0,0 +1,182 @@
+# Makefile for zlib, derived from Makefile.dj2.
+# Modified for mingw32 by C. Spieler, 6/16/98.
+# Updated for zlib 1.2.x by Christian Spieler and Cosmin Truta, Mar-2003.
+# Last updated: Mar 2012.
+# Tested under Cygwin and MinGW.
+
+# Copyright (C) 1995-2003 Jean-loup Gailly.
+# For conditions of distribution and use, see copyright notice in zlib.h
+
+# To compile, or to compile and test, type from the top level zlib directory:
+#
+#   make -fwin32/Makefile.gcc;  make test testdll -fwin32/Makefile.gcc
+#
+# To use the asm code, type:
+#   cp contrib/asm?86/match.S ./match.S
+#   make LOC=-DASMV OBJA=match.o -fwin32/Makefile.gcc
+#
+# To install libz.a, zconf.h and zlib.h in the system directories, type:
+#
+#   make install -fwin32/Makefile.gcc
+#
+# BINARY_PATH, INCLUDE_PATH and LIBRARY_PATH must be set.
+#
+# To install the shared lib, append SHARED_MODE=1 to the make command :
+#
+#   make install -fwin32/Makefile.gcc SHARED_MODE=1
+
+# Note:
+# If the platform is *not* MinGW (e.g. it is Cygwin or UWIN),
+# the DLL name should be changed from "zlib1.dll".
+
+STATICLIB = libz.a
+SHAREDLIB = zlib1.dll
+IMPLIB    = libz.dll.a
+
+#
+# Set to 1 if shared object needs to be installed
+#
+SHARED_MODE=0
+
+#LOC = -DASMV
+#LOC = -DZLIB_DEBUG -g
+
+PREFIX =
+CC = $(PREFIX)gcc
+CFLAGS = $(LOC) -O3 -Wall
+
+AS = $(CC)
+ASFLAGS = $(LOC) -Wall
+
+LD = $(CC)
+LDFLAGS = $(LOC)
+
+AR = $(PREFIX)ar
+ARFLAGS = rcs
+
+RC = $(PREFIX)windres
+RCFLAGS = --define GCC_WINDRES
+
+STRIP = $(PREFIX)strip
+
+CP = cp -fp
+# If GNU install is available, replace $(CP) with install.
+INSTALL = $(CP)
+RM = rm -f
+
+prefix ?= /usr/local
+exec_prefix = $(prefix)
+
+OBJS = adler32.o compress.o crc32.o deflate.o gzclose.o gzlib.o gzread.o \
+       gzwrite.o infback.o inffast.o inflate.o inftrees.o trees.o uncompr.o zutil.o
+OBJA =
+
+all: $(STATICLIB) $(SHAREDLIB) $(IMPLIB) example.exe minigzip.exe example_d.exe minigzip_d.exe
+
+test: example.exe minigzip.exe
+	./example
+	echo hello world | ./minigzip | ./minigzip -d
+
+testdll: example_d.exe minigzip_d.exe
+	./example_d
+	echo hello world | ./minigzip_d | ./minigzip_d -d
+
+.c.o:
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+.S.o:
+	$(AS) $(ASFLAGS) -c -o $@ $<
+
+$(STATICLIB): $(OBJS) $(OBJA)
+	$(AR) $(ARFLAGS) $@ $(OBJS) $(OBJA)
+
+$(IMPLIB): $(SHAREDLIB)
+
+$(SHAREDLIB): win32/zlib.def $(OBJS) $(OBJA) zlibrc.o
+	$(CC) -shared -Wl,--out-implib,$(IMPLIB) $(LDFLAGS) \
+	-o $@ win32/zlib.def $(OBJS) $(OBJA) zlibrc.o
+	$(STRIP) $@
+
+example.exe: example.o $(STATICLIB)
+	$(LD) $(LDFLAGS) -o $@ example.o $(STATICLIB)
+	$(STRIP) $@
+
+minigzip.exe: minigzip.o $(STATICLIB)
+	$(LD) $(LDFLAGS) -o $@ minigzip.o $(STATICLIB)
+	$(STRIP) $@
+
+example_d.exe: example.o $(IMPLIB)
+	$(LD) $(LDFLAGS) -o $@ example.o $(IMPLIB)
+	$(STRIP) $@
+
+minigzip_d.exe: minigzip.o $(IMPLIB)
+	$(LD) $(LDFLAGS) -o $@ minigzip.o $(IMPLIB)
+	$(STRIP) $@
+
+example.o: test/example.c zlib.h zconf.h
+	$(CC) $(CFLAGS) -I. -c -o $@ test/example.c
+
+minigzip.o: test/minigzip.c zlib.h zconf.h
+	$(CC) $(CFLAGS) -I. -c -o $@ test/minigzip.c
+
+zlibrc.o: win32/zlib1.rc
+	$(RC) $(RCFLAGS) -o $@ win32/zlib1.rc
+
+.PHONY: install uninstall clean
+
+install: zlib.h zconf.h $(STATICLIB) $(IMPLIB)
+	@if test -z "$(DESTDIR)$(INCLUDE_PATH)" -o -z "$(DESTDIR)$(LIBRARY_PATH)" -o -z "$(DESTDIR)$(BINARY_PATH)"; then \
+		echo INCLUDE_PATH, LIBRARY_PATH, and BINARY_PATH must be specified; \
+		exit 1; \
+	fi
+	-@mkdir -p '$(DESTDIR)$(INCLUDE_PATH)'
+	-@mkdir -p '$(DESTDIR)$(LIBRARY_PATH)' '$(DESTDIR)$(LIBRARY_PATH)'/pkgconfig
+	-if [ "$(SHARED_MODE)" = "1" ]; then \
+		mkdir -p '$(DESTDIR)$(BINARY_PATH)'; \
+		$(INSTALL) $(SHAREDLIB) '$(DESTDIR)$(BINARY_PATH)'; \
+		$(INSTALL) $(IMPLIB) '$(DESTDIR)$(LIBRARY_PATH)'; \
+	fi
+	-$(INSTALL) zlib.h '$(DESTDIR)$(INCLUDE_PATH)'
+	-$(INSTALL) zconf.h '$(DESTDIR)$(INCLUDE_PATH)'
+	-$(INSTALL) $(STATICLIB) '$(DESTDIR)$(LIBRARY_PATH)'
+	sed \
+		-e 's|@prefix@|${prefix}|g' \
+		-e 's|@exec_prefix@|${exec_prefix}|g' \
+		-e 's|@libdir@|$(LIBRARY_PATH)|g' \
+		-e 's|@sharedlibdir@|$(LIBRARY_PATH)|g' \
+		-e 's|@includedir@|$(INCLUDE_PATH)|g' \
+		-e 's|@VERSION@|'`sed -n -e '/VERSION "/s/.*"\(.*\)".*/\1/p' zlib.h`'|g' \
+		zlib.pc.in > '$(DESTDIR)$(LIBRARY_PATH)'/pkgconfig/zlib.pc
+
+uninstall:
+	-if [ "$(SHARED_MODE)" = "1" ]; then \
+		$(RM) '$(DESTDIR)$(BINARY_PATH)'/$(SHAREDLIB); \
+		$(RM) '$(DESTDIR)$(LIBRARY_PATH)'/$(IMPLIB); \
+	fi
+	-$(RM) '$(DESTDIR)$(INCLUDE_PATH)'/zlib.h
+	-$(RM) '$(DESTDIR)$(INCLUDE_PATH)'/zconf.h
+	-$(RM) '$(DESTDIR)$(LIBRARY_PATH)'/$(STATICLIB)
+
+clean:
+	-$(RM) $(STATICLIB)
+	-$(RM) $(SHAREDLIB)
+	-$(RM) $(IMPLIB)
+	-$(RM) *.o
+	-$(RM) *.exe
+	-$(RM) foo.gz
+
+adler32.o: zlib.h zconf.h
+compress.o: zlib.h zconf.h
+crc32.o: crc32.h zlib.h zconf.h
+deflate.o: deflate.h zutil.h zlib.h zconf.h
+gzclose.o: zlib.h zconf.h gzguts.h
+gzlib.o: zlib.h zconf.h gzguts.h
+gzread.o: zlib.h zconf.h gzguts.h
+gzwrite.o: zlib.h zconf.h gzguts.h
+inffast.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+inflate.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+infback.o: zutil.h zlib.h zconf.h inftrees.h inflate.h inffast.h
+inftrees.o: zutil.h zlib.h zconf.h inftrees.h
+trees.o: deflate.h zutil.h zlib.h zconf.h trees.h
+uncompr.o: zlib.h zconf.h
+zutil.o: zutil.h zlib.h zconf.h
diff --git a/xs/src/png/zlib/win32/Makefile.msc b/xs/src/png/zlib/win32/Makefile.msc
new file mode 100644
index 000000000..6831882de
--- /dev/null
+++ b/xs/src/png/zlib/win32/Makefile.msc
@@ -0,0 +1,163 @@
+# Makefile for zlib using Microsoft (Visual) C
+# zlib is copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+#
+# Usage:
+#   nmake -f win32/Makefile.msc                          (standard build)
+#   nmake -f win32/Makefile.msc LOC=-DFOO                (nonstandard build)
+#   nmake -f win32/Makefile.msc LOC="-DASMV -DASMINF" \
+#         OBJA="inffas32.obj match686.obj"               (use ASM code, x86)
+#   nmake -f win32/Makefile.msc AS=ml64 LOC="-DASMV -DASMINF -I." \
+#         OBJA="inffasx64.obj gvmat64.obj inffas8664.obj"  (use ASM code, x64)
+
+# The toplevel directory of the source tree.
+#
+TOP = .
+
+# optional build flags
+LOC =
+
+# variables
+STATICLIB = zlib.lib
+SHAREDLIB = zlib1.dll
+IMPLIB    = zdll.lib
+
+CC = cl
+AS = ml
+LD = link
+AR = lib
+RC = rc
+CFLAGS  = -nologo -MD -W3 -O2 -Oy- -Zi -Fd"zlib" $(LOC)
+WFLAGS  = -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE
+ASFLAGS = -coff -Zi $(LOC)
+LDFLAGS = -nologo -debug -incremental:no -opt:ref
+ARFLAGS = -nologo
+RCFLAGS = /dWIN32 /r
+
+OBJS = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj \
+       gzwrite.obj infback.obj inflate.obj inftrees.obj inffast.obj trees.obj uncompr.obj zutil.obj
+OBJA =
+
+
+# targets
+all: $(STATICLIB) $(SHAREDLIB) $(IMPLIB) \
+     example.exe minigzip.exe example_d.exe minigzip_d.exe
+
+$(STATICLIB): $(OBJS) $(OBJA)
+	$(AR) $(ARFLAGS) -out:$@ $(OBJS) $(OBJA)
+
+$(IMPLIB): $(SHAREDLIB)
+
+$(SHAREDLIB): $(TOP)/win32/zlib.def $(OBJS) $(OBJA) zlib1.res
+	$(LD) $(LDFLAGS) -def:$(TOP)/win32/zlib.def -dll -implib:$(IMPLIB) \
+	  -out:$@ -base:0x5A4C0000 $(OBJS) $(OBJA) zlib1.res
+	if exist $@.manifest \
+	  mt -nologo -manifest $@.manifest -outputresource:$@;2
+
+example.exe: example.obj $(STATICLIB)
+	$(LD) $(LDFLAGS) example.obj $(STATICLIB)
+	if exist $@.manifest \
+	  mt -nologo -manifest $@.manifest -outputresource:$@;1
+
+minigzip.exe: minigzip.obj $(STATICLIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(STATICLIB)
+	if exist $@.manifest \
+	  mt -nologo -manifest $@.manifest -outputresource:$@;1
+
+example_d.exe: example.obj $(IMPLIB)
+	$(LD) $(LDFLAGS) -out:$@ example.obj $(IMPLIB)
+	if exist $@.manifest \
+	  mt -nologo -manifest $@.manifest -outputresource:$@;1
+
+minigzip_d.exe: minigzip.obj $(IMPLIB)
+	$(LD) $(LDFLAGS) -out:$@ minigzip.obj $(IMPLIB)
+	if exist $@.manifest \
+	  mt -nologo -manifest $@.manifest -outputresource:$@;1
+
+{$(TOP)}.c.obj:
+	$(CC) -c $(WFLAGS) $(CFLAGS) $<
+
+{$(TOP)/test}.c.obj:
+	$(CC) -c -I$(TOP) $(WFLAGS) $(CFLAGS) $<
+
+{$(TOP)/contrib/masmx64}.c.obj:
+	$(CC) -c $(WFLAGS) $(CFLAGS) $<
+
+{$(TOP)/contrib/masmx64}.asm.obj:
+	$(AS) -c $(ASFLAGS) $<
+
+{$(TOP)/contrib/masmx86}.asm.obj:
+	$(AS) -c $(ASFLAGS) $<
+
+adler32.obj: $(TOP)/adler32.c $(TOP)/zlib.h $(TOP)/zconf.h
+
+compress.obj: $(TOP)/compress.c $(TOP)/zlib.h $(TOP)/zconf.h
+
+crc32.obj: $(TOP)/crc32.c $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/crc32.h
+
+deflate.obj: $(TOP)/deflate.c $(TOP)/deflate.h $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h
+
+gzclose.obj: $(TOP)/gzclose.c $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/gzguts.h
+
+gzlib.obj: $(TOP)/gzlib.c $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/gzguts.h
+
+gzread.obj: $(TOP)/gzread.c $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/gzguts.h
+
+gzwrite.obj: $(TOP)/gzwrite.c $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/gzguts.h
+
+infback.obj: $(TOP)/infback.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/inftrees.h $(TOP)/inflate.h \
+             $(TOP)/inffast.h $(TOP)/inffixed.h
+
+inffast.obj: $(TOP)/inffast.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/inftrees.h $(TOP)/inflate.h \
+             $(TOP)/inffast.h
+
+inflate.obj: $(TOP)/inflate.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/inftrees.h $(TOP)/inflate.h \
+             $(TOP)/inffast.h $(TOP)/inffixed.h
+
+inftrees.obj: $(TOP)/inftrees.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/inftrees.h
+
+trees.obj: $(TOP)/trees.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h $(TOP)/deflate.h $(TOP)/trees.h
+
+uncompr.obj: $(TOP)/uncompr.c $(TOP)/zlib.h $(TOP)/zconf.h
+
+zutil.obj: $(TOP)/zutil.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h
+
+gvmat64.obj: $(TOP)/contrib\masmx64\gvmat64.asm
+
+inffasx64.obj: $(TOP)/contrib\masmx64\inffasx64.asm
+
+inffas8664.obj: $(TOP)/contrib\masmx64\inffas8664.c $(TOP)/zutil.h $(TOP)/zlib.h $(TOP)/zconf.h \
+		$(TOP)/inftrees.h $(TOP)/inflate.h $(TOP)/inffast.h
+
+inffas32.obj: $(TOP)/contrib\masmx86\inffas32.asm
+
+match686.obj: $(TOP)/contrib\masmx86\match686.asm
+
+example.obj: $(TOP)/test/example.c $(TOP)/zlib.h $(TOP)/zconf.h
+
+minigzip.obj: $(TOP)/test/minigzip.c $(TOP)/zlib.h $(TOP)/zconf.h
+
+zlib1.res: $(TOP)/win32/zlib1.rc
+	$(RC) $(RCFLAGS) /fo$@ $(TOP)/win32/zlib1.rc
+
+# testing
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+testdll: example_d.exe minigzip_d.exe
+	example_d
+	echo hello world | minigzip_d | minigzip_d -d
+
+
+# cleanup
+clean:
+	-del $(STATICLIB)
+	-del $(SHAREDLIB)
+	-del $(IMPLIB)
+	-del *.obj
+	-del *.res
+	-del *.exp
+	-del *.exe
+	-del *.pdb
+	-del *.manifest
+	-del foo.gz
diff --git a/xs/src/png/zlib/win32/README-WIN32.txt b/xs/src/png/zlib/win32/README-WIN32.txt
new file mode 100644
index 000000000..df7ab7f4b
--- /dev/null
+++ b/xs/src/png/zlib/win32/README-WIN32.txt
@@ -0,0 +1,103 @@
+ZLIB DATA COMPRESSION LIBRARY
+
+zlib 1.2.11 is a general purpose data compression library.  All the code is
+thread safe.  The data format used by the zlib library is described by RFCs
+(Request for Comments) 1950 to 1952 in the files
+http://www.ietf.org/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate format)
+and rfc1952.txt (gzip format).
+
+All functions of the compression library are documented in the file zlib.h
+(volunteer to write man pages welcome, contact zlib@gzip.org).  Two compiled
+examples are distributed in this package, example and minigzip.  The example_d
+and minigzip_d flavors validate that the zlib1.dll file is working correctly.
+
+Questions about zlib should be sent to <zlib@gzip.org>.  The zlib home page
+is http://zlib.net/ .  Before reporting a problem, please check this site to
+verify that you have the latest version of zlib; otherwise get the latest
+version and check whether the problem still exists or not.
+
+PLEASE read DLL_FAQ.txt, and the the zlib FAQ http://zlib.net/zlib_faq.html
+before asking for help.
+
+
+Manifest:
+
+The package zlib-1.2.11-win32-x86.zip will contain the following files:
+
+  README-WIN32.txt This document
+  ChangeLog        Changes since previous zlib packages
+  DLL_FAQ.txt      Frequently asked questions about zlib1.dll
+  zlib.3.pdf       Documentation of this library in Adobe Acrobat format
+
+  example.exe      A statically-bound example (using zlib.lib, not the dll)
+  example.pdb      Symbolic information for debugging example.exe
+
+  example_d.exe    A zlib1.dll bound example (using zdll.lib)
+  example_d.pdb    Symbolic information for debugging example_d.exe
+
+  minigzip.exe     A statically-bound test program (using zlib.lib, not the dll)
+  minigzip.pdb     Symbolic information for debugging minigzip.exe
+
+  minigzip_d.exe   A zlib1.dll bound test program (using zdll.lib)
+  minigzip_d.pdb   Symbolic information for debugging minigzip_d.exe
+
+  zlib.h           Install these files into the compilers' INCLUDE path to
+  zconf.h          compile programs which use zlib.lib or zdll.lib
+
+  zdll.lib         Install these files into the compilers' LIB path if linking
+  zdll.exp         a compiled program to the zlib1.dll binary
+
+  zlib.lib         Install these files into the compilers' LIB path to link zlib
+  zlib.pdb         into compiled programs, without zlib1.dll runtime dependency
+                   (zlib.pdb provides debugging info to the compile time linker)
+
+  zlib1.dll        Install this binary shared library into the system PATH, or
+                   the program's runtime directory (where the .exe resides)
+  zlib1.pdb        Install in the same directory as zlib1.dll, in order to debug
+                   an application crash using WinDbg or similar tools.
+
+All .pdb files above are entirely optional, but are very useful to a developer
+attempting to diagnose program misbehavior or a crash.  Many additional
+important files for developers can be found in the zlib127.zip source package
+available from http://zlib.net/ - review that package's README file for details.
+
+
+Acknowledgments:
+
+The deflate format used by zlib was defined by Phil Katz.  The deflate and
+zlib specifications were written by L.  Peter Deutsch.  Thanks to all the
+people who reported problems and suggested various improvements in zlib; they
+are too numerous to cite here.
+
+
+Copyright notice:
+
+  (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+If you use the zlib library in a product, we would appreciate *not* receiving
+lengthy legal documents to sign.  The sources are provided for free but without
+warranty of any kind.  The library has been entirely written by Jean-loup
+Gailly and Mark Adler; it does not include third-party code.
+
+If you redistribute modified sources, we would appreciate that you include in
+the file ChangeLog history information documenting your changes.  Please read
+the FAQ for more information on the distribution of modified source versions.
diff --git a/xs/src/png/zlib/win32/VisualC.txt b/xs/src/png/zlib/win32/VisualC.txt
new file mode 100644
index 000000000..1005b2194
--- /dev/null
+++ b/xs/src/png/zlib/win32/VisualC.txt
@@ -0,0 +1,3 @@
+
+To build zlib using the Microsoft Visual C++ environment,
+use the appropriate project from the contrib/vstudio/ directory.
diff --git a/xs/src/png/zlib/win32/zlib.def b/xs/src/png/zlib/win32/zlib.def
new file mode 100644
index 000000000..a2188b000
--- /dev/null
+++ b/xs/src/png/zlib/win32/zlib.def
@@ -0,0 +1,94 @@
+; zlib data compression library
+EXPORTS
+; basic functions
+    zlibVersion
+    deflate
+    deflateEnd
+    inflate
+    inflateEnd
+; advanced functions
+    deflateSetDictionary
+    deflateGetDictionary
+    deflateCopy
+    deflateReset
+    deflateParams
+    deflateTune
+    deflateBound
+    deflatePending
+    deflatePrime
+    deflateSetHeader
+    inflateSetDictionary
+    inflateGetDictionary
+    inflateSync
+    inflateCopy
+    inflateReset
+    inflateReset2
+    inflatePrime
+    inflateMark
+    inflateGetHeader
+    inflateBack
+    inflateBackEnd
+    zlibCompileFlags
+; utility functions
+    compress
+    compress2
+    compressBound
+    uncompress
+    uncompress2
+    gzopen
+    gzdopen
+    gzbuffer
+    gzsetparams
+    gzread
+    gzfread
+    gzwrite
+    gzfwrite
+    gzprintf
+    gzvprintf
+    gzputs
+    gzgets
+    gzputc
+    gzgetc
+    gzungetc
+    gzflush
+    gzseek
+    gzrewind
+    gztell
+    gzoffset
+    gzeof
+    gzdirect
+    gzclose
+    gzclose_r
+    gzclose_w
+    gzerror
+    gzclearerr
+; large file functions
+    gzopen64
+    gzseek64
+    gztell64
+    gzoffset64
+    adler32_combine64
+    crc32_combine64
+; checksum functions
+    adler32
+    adler32_z
+    crc32
+    crc32_z
+    adler32_combine
+    crc32_combine
+; various hacks, don't look :)
+    deflateInit_
+    deflateInit2_
+    inflateInit_
+    inflateInit2_
+    inflateBackInit_
+    gzgetc_
+    zError
+    inflateSyncPoint
+    get_crc_table
+    inflateUndermine
+    inflateValidate
+    inflateCodesUsed
+    inflateResetKeep
+    deflateResetKeep
+    gzopen_w
diff --git a/xs/src/png/zlib/win32/zlib1.rc b/xs/src/png/zlib/win32/zlib1.rc
new file mode 100644
index 000000000..234e641c3
--- /dev/null
+++ b/xs/src/png/zlib/win32/zlib1.rc
@@ -0,0 +1,40 @@
+#include <winver.h>
+#include "../zlib.h"
+
+#ifdef GCC_WINDRES
+VS_VERSION_INFO		VERSIONINFO
+#else
+VS_VERSION_INFO		VERSIONINFO	MOVEABLE IMPURE LOADONCALL DISCARDABLE
+#endif
+  FILEVERSION		ZLIB_VER_MAJOR,ZLIB_VER_MINOR,ZLIB_VER_REVISION,0
+  PRODUCTVERSION	ZLIB_VER_MAJOR,ZLIB_VER_MINOR,ZLIB_VER_REVISION,0
+  FILEFLAGSMASK		VS_FFI_FILEFLAGSMASK
+#ifdef _DEBUG
+  FILEFLAGS		1
+#else
+  FILEFLAGS		0
+#endif
+  FILEOS		VOS__WINDOWS32
+  FILETYPE		VFT_DLL
+  FILESUBTYPE		0	// not used
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    //language ID = U.S. English, char set = Windows, Multilingual
+    BEGIN
+      VALUE "FileDescription",	"zlib data compression library\0"
+      VALUE "FileVersion",	ZLIB_VERSION "\0"
+      VALUE "InternalName",	"zlib1.dll\0"
+      VALUE "LegalCopyright",	"(C) 1995-2017 Jean-loup Gailly & Mark Adler\0"
+      VALUE "OriginalFilename",	"zlib1.dll\0"
+      VALUE "ProductName",	"zlib\0"
+      VALUE "ProductVersion",	ZLIB_VERSION "\0"
+      VALUE "Comments",		"For more information visit http://www.zlib.net/\0"
+    END
+  END
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x0409, 1252
+  END
+END
diff --git a/xs/src/png/zlib/zconf.h.cmakein b/xs/src/png/zlib/zconf.h.cmakein
new file mode 100644
index 000000000..a7f24cce6
--- /dev/null
+++ b/xs/src/png/zlib/zconf.h.cmakein
@@ -0,0 +1,536 @@
+/* zconf.h -- configuration of the zlib compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZCONF_H
+#define ZCONF_H
+#cmakedefine Z_PREFIX
+#cmakedefine Z_HAVE_UNISTD_H
+
+/*
+ * If you *really* need a unique prefix for all types and library functions,
+ * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
+ * Even better than compiling with -DZ_PREFIX would be to use configure to set
+ * this permanently in zconf.h using "./configure --zprefix".
+ */
+#ifdef Z_PREFIX     /* may be set to #if 1 by ./configure */
+#  define Z_PREFIX_SET
+
+/* all linked symbols and init macros */
+#  define _dist_code            z__dist_code
+#  define _length_code          z__length_code
+#  define _tr_align             z__tr_align
+#  define _tr_flush_bits        z__tr_flush_bits
+#  define _tr_flush_block       z__tr_flush_block
+#  define _tr_init              z__tr_init
+#  define _tr_stored_block      z__tr_stored_block
+#  define _tr_tally             z__tr_tally
+#  define adler32               z_adler32
+#  define adler32_combine       z_adler32_combine
+#  define adler32_combine64     z_adler32_combine64
+#  define adler32_z             z_adler32_z
+#  ifndef Z_SOLO
+#    define compress              z_compress
+#    define compress2             z_compress2
+#    define compressBound         z_compressBound
+#  endif
+#  define crc32                 z_crc32
+#  define crc32_combine         z_crc32_combine
+#  define crc32_combine64       z_crc32_combine64
+#  define crc32_z               z_crc32_z
+#  define deflate               z_deflate
+#  define deflateBound          z_deflateBound
+#  define deflateCopy           z_deflateCopy
+#  define deflateEnd            z_deflateEnd
+#  define deflateGetDictionary  z_deflateGetDictionary
+#  define deflateInit           z_deflateInit
+#  define deflateInit2          z_deflateInit2
+#  define deflateInit2_         z_deflateInit2_
+#  define deflateInit_          z_deflateInit_
+#  define deflateParams         z_deflateParams
+#  define deflatePending        z_deflatePending
+#  define deflatePrime          z_deflatePrime
+#  define deflateReset          z_deflateReset
+#  define deflateResetKeep      z_deflateResetKeep
+#  define deflateSetDictionary  z_deflateSetDictionary
+#  define deflateSetHeader      z_deflateSetHeader
+#  define deflateTune           z_deflateTune
+#  define deflate_copyright     z_deflate_copyright
+#  define get_crc_table         z_get_crc_table
+#  ifndef Z_SOLO
+#    define gz_error              z_gz_error
+#    define gz_intmax             z_gz_intmax
+#    define gz_strwinerror        z_gz_strwinerror
+#    define gzbuffer              z_gzbuffer
+#    define gzclearerr            z_gzclearerr
+#    define gzclose               z_gzclose
+#    define gzclose_r             z_gzclose_r
+#    define gzclose_w             z_gzclose_w
+#    define gzdirect              z_gzdirect
+#    define gzdopen               z_gzdopen
+#    define gzeof                 z_gzeof
+#    define gzerror               z_gzerror
+#    define gzflush               z_gzflush
+#    define gzfread               z_gzfread
+#    define gzfwrite              z_gzfwrite
+#    define gzgetc                z_gzgetc
+#    define gzgetc_               z_gzgetc_
+#    define gzgets                z_gzgets
+#    define gzoffset              z_gzoffset
+#    define gzoffset64            z_gzoffset64
+#    define gzopen                z_gzopen
+#    define gzopen64              z_gzopen64
+#    ifdef _WIN32
+#      define gzopen_w              z_gzopen_w
+#    endif
+#    define gzprintf              z_gzprintf
+#    define gzputc                z_gzputc
+#    define gzputs                z_gzputs
+#    define gzread                z_gzread
+#    define gzrewind              z_gzrewind
+#    define gzseek                z_gzseek
+#    define gzseek64              z_gzseek64
+#    define gzsetparams           z_gzsetparams
+#    define gztell                z_gztell
+#    define gztell64              z_gztell64
+#    define gzungetc              z_gzungetc
+#    define gzvprintf             z_gzvprintf
+#    define gzwrite               z_gzwrite
+#  endif
+#  define inflate               z_inflate
+#  define inflateBack           z_inflateBack
+#  define inflateBackEnd        z_inflateBackEnd
+#  define inflateBackInit       z_inflateBackInit
+#  define inflateBackInit_      z_inflateBackInit_
+#  define inflateCodesUsed      z_inflateCodesUsed
+#  define inflateCopy           z_inflateCopy
+#  define inflateEnd            z_inflateEnd
+#  define inflateGetDictionary  z_inflateGetDictionary
+#  define inflateGetHeader      z_inflateGetHeader
+#  define inflateInit           z_inflateInit
+#  define inflateInit2          z_inflateInit2
+#  define inflateInit2_         z_inflateInit2_
+#  define inflateInit_          z_inflateInit_
+#  define inflateMark           z_inflateMark
+#  define inflatePrime          z_inflatePrime
+#  define inflateReset          z_inflateReset
+#  define inflateReset2         z_inflateReset2
+#  define inflateResetKeep      z_inflateResetKeep
+#  define inflateSetDictionary  z_inflateSetDictionary
+#  define inflateSync           z_inflateSync
+#  define inflateSyncPoint      z_inflateSyncPoint
+#  define inflateUndermine      z_inflateUndermine
+#  define inflateValidate       z_inflateValidate
+#  define inflate_copyright     z_inflate_copyright
+#  define inflate_fast          z_inflate_fast
+#  define inflate_table         z_inflate_table
+#  ifndef Z_SOLO
+#    define uncompress            z_uncompress
+#    define uncompress2           z_uncompress2
+#  endif
+#  define zError                z_zError
+#  ifndef Z_SOLO
+#    define zcalloc               z_zcalloc
+#    define zcfree                z_zcfree
+#  endif
+#  define zlibCompileFlags      z_zlibCompileFlags
+#  define zlibVersion           z_zlibVersion
+
+/* all zlib typedefs in zlib.h and zconf.h */
+#  define Byte                  z_Byte
+#  define Bytef                 z_Bytef
+#  define alloc_func            z_alloc_func
+#  define charf                 z_charf
+#  define free_func             z_free_func
+#  ifndef Z_SOLO
+#    define gzFile                z_gzFile
+#  endif
+#  define gz_header             z_gz_header
+#  define gz_headerp            z_gz_headerp
+#  define in_func               z_in_func
+#  define intf                  z_intf
+#  define out_func              z_out_func
+#  define uInt                  z_uInt
+#  define uIntf                 z_uIntf
+#  define uLong                 z_uLong
+#  define uLongf                z_uLongf
+#  define voidp                 z_voidp
+#  define voidpc                z_voidpc
+#  define voidpf                z_voidpf
+
+/* all zlib structs in zlib.h and zconf.h */
+#  define gz_header_s           z_gz_header_s
+#  define internal_state        z_internal_state
+
+#endif
+
+#if defined(__MSDOS__) && !defined(MSDOS)
+#  define MSDOS
+#endif
+#if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
+#  define OS2
+#endif
+#if defined(_WINDOWS) && !defined(WINDOWS)
+#  define WINDOWS
+#endif
+#if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
+#  ifndef WIN32
+#    define WIN32
+#  endif
+#endif
+#if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
+#  if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
+#    ifndef SYS16BIT
+#      define SYS16BIT
+#    endif
+#  endif
+#endif
+
+/*
+ * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
+ * than 64k bytes at a time (needed on systems with 16-bit int).
+ */
+#ifdef SYS16BIT
+#  define MAXSEG_64K
+#endif
+#ifdef MSDOS
+#  define UNALIGNED_OK
+#endif
+
+#ifdef __STDC_VERSION__
+#  ifndef STDC
+#    define STDC
+#  endif
+#  if __STDC_VERSION__ >= 199901L
+#    ifndef STDC99
+#      define STDC99
+#    endif
+#  endif
+#endif
+#if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
+#  define STDC
+#endif
+
+#if defined(__OS400__) && !defined(STDC)    /* iSeries (formerly AS/400). */
+#  define STDC
+#endif
+
+#ifndef STDC
+#  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
+#    define const       /* note: need a more gentle solution here */
+#  endif
+#endif
+
+#if defined(ZLIB_CONST) && !defined(z_const)
+#  define z_const const
+#else
+#  define z_const
+#endif
+
+#ifdef Z_SOLO
+   typedef unsigned long z_size_t;
+#else
+#  define z_longlong long long
+#  if defined(NO_SIZE_T)
+     typedef unsigned NO_SIZE_T z_size_t;
+#  elif defined(STDC)
+#    include <stddef.h>
+     typedef size_t z_size_t;
+#  else
+     typedef unsigned long z_size_t;
+#  endif
+#  undef z_longlong
+#endif
+
+/* Maximum value for memLevel in deflateInit2 */
+#ifndef MAX_MEM_LEVEL
+#  ifdef MAXSEG_64K
+#    define MAX_MEM_LEVEL 8
+#  else
+#    define MAX_MEM_LEVEL 9
+#  endif
+#endif
+
+/* Maximum value for windowBits in deflateInit2 and inflateInit2.
+ * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
+ * created by gzip. (Files created by minigzip can still be extracted by
+ * gzip.)
+ */
+#ifndef MAX_WBITS
+#  define MAX_WBITS   15 /* 32K LZ77 window */
+#endif
+
+/* The memory requirements for deflate are (in bytes):
+            (1 << (windowBits+2)) +  (1 << (memLevel+9))
+ that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
+ plus a few kilobytes for small objects. For example, if you want to reduce
+ the default memory requirements from 256K to 128K, compile with
+     make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
+ Of course this will generally degrade compression (there's no free lunch).
+
+   The memory requirements for inflate are (in bytes) 1 << windowBits
+ that is, 32K for windowBits=15 (default value) plus about 7 kilobytes
+ for small objects.
+*/
+
+                        /* Type declarations */
+
+#ifndef OF /* function prototypes */
+#  ifdef STDC
+#    define OF(args)  args
+#  else
+#    define OF(args)  ()
+#  endif
+#endif
+
+#ifndef Z_ARG /* function prototypes for stdarg */
+#  if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#    define Z_ARG(args)  args
+#  else
+#    define Z_ARG(args)  ()
+#  endif
+#endif
+
+/* The following definitions for FAR are needed only for MSDOS mixed
+ * model programming (small or medium model with some far allocations).
+ * This was tested only with MSC; for other MSDOS compilers you may have
+ * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
+ * just define FAR to be empty.
+ */
+#ifdef SYS16BIT
+#  if defined(M_I86SM) || defined(M_I86MM)
+     /* MSC small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef _MSC_VER
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#  if (defined(__SMALL__) || defined(__MEDIUM__))
+     /* Turbo C small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef __BORLANDC__
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#endif
+
+#if defined(WINDOWS) || defined(WIN32)
+   /* If building or using zlib as a DLL, define ZLIB_DLL.
+    * This is not mandatory, but it offers a little performance increase.
+    */
+#  ifdef ZLIB_DLL
+#    if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
+#      ifdef ZLIB_INTERNAL
+#        define ZEXTERN extern __declspec(dllexport)
+#      else
+#        define ZEXTERN extern __declspec(dllimport)
+#      endif
+#    endif
+#  endif  /* ZLIB_DLL */
+   /* If building or using zlib with the WINAPI/WINAPIV calling convention,
+    * define ZLIB_WINAPI.
+    * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
+    */
+#  ifdef ZLIB_WINAPI
+#    ifdef FAR
+#      undef FAR
+#    endif
+#    include <windows.h>
+     /* No need for _export, use ZLIB.DEF instead. */
+     /* For complete Windows compatibility, use WINAPI, not __stdcall. */
+#    define ZEXPORT WINAPI
+#    ifdef WIN32
+#      define ZEXPORTVA WINAPIV
+#    else
+#      define ZEXPORTVA FAR CDECL
+#    endif
+#  endif
+#endif
+
+#if defined (__BEOS__)
+#  ifdef ZLIB_DLL
+#    ifdef ZLIB_INTERNAL
+#      define ZEXPORT   __declspec(dllexport)
+#      define ZEXPORTVA __declspec(dllexport)
+#    else
+#      define ZEXPORT   __declspec(dllimport)
+#      define ZEXPORTVA __declspec(dllimport)
+#    endif
+#  endif
+#endif
+
+#ifndef ZEXTERN
+#  define ZEXTERN extern
+#endif
+#ifndef ZEXPORT
+#  define ZEXPORT
+#endif
+#ifndef ZEXPORTVA
+#  define ZEXPORTVA
+#endif
+
+#ifndef FAR
+#  define FAR
+#endif
+
+#if !defined(__MACTYPES__)
+typedef unsigned char  Byte;  /* 8 bits */
+#endif
+typedef unsigned int   uInt;  /* 16 bits or more */
+typedef unsigned long  uLong; /* 32 bits or more */
+
+#ifdef SMALL_MEDIUM
+   /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
+#  define Bytef Byte FAR
+#else
+   typedef Byte  FAR Bytef;
+#endif
+typedef char  FAR charf;
+typedef int   FAR intf;
+typedef uInt  FAR uIntf;
+typedef uLong FAR uLongf;
+
+#ifdef STDC
+   typedef void const *voidpc;
+   typedef void FAR   *voidpf;
+   typedef void       *voidp;
+#else
+   typedef Byte const *voidpc;
+   typedef Byte FAR   *voidpf;
+   typedef Byte       *voidp;
+#endif
+
+#if !defined(Z_U4) && !defined(Z_SOLO) && defined(STDC)
+#  include <limits.h>
+#  if (UINT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned
+#  elif (ULONG_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned long
+#  elif (USHRT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned short
+#  endif
+#endif
+
+#ifdef Z_U4
+   typedef Z_U4 z_crc_t;
+#else
+   typedef unsigned long z_crc_t;
+#endif
+
+#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_UNISTD_H
+#endif
+
+#ifdef HAVE_STDARG_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_STDARG_H
+#endif
+
+#ifdef STDC
+#  ifndef Z_SOLO
+#    include <sys/types.h>      /* for off_t */
+#  endif
+#endif
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+#    include <stdarg.h>         /* for va_list */
+#  endif
+#endif
+
+#ifdef _WIN32
+#  ifndef Z_SOLO
+#    include <stddef.h>         /* for wchar_t */
+#  endif
+#endif
+
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if defined(_LARGEFILE64_SOURCE) && -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
+#if defined(__WATCOMC__) && !defined(Z_HAVE_UNISTD_H)
+#  define Z_HAVE_UNISTD_H
+#endif
+#ifndef Z_SOLO
+#  if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
+#    include <unistd.h>         /* for SEEK_*, off_t, and _LFS64_LARGEFILE */
+#    ifdef VMS
+#      include <unixio.h>       /* for off_t */
+#    endif
+#    ifndef z_off_t
+#      define z_off_t off_t
+#    endif
+#  endif
+#endif
+
+#if defined(_LFS64_LARGEFILE) && _LFS64_LARGEFILE-0
+#  define Z_LFS64
+#endif
+
+#if defined(_LARGEFILE64_SOURCE) && defined(Z_LFS64)
+#  define Z_LARGE64
+#endif
+
+#if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS-0 == 64 && defined(Z_LFS64)
+#  define Z_WANT64
+#endif
+
+#if !defined(SEEK_SET) && !defined(Z_SOLO)
+#  define SEEK_SET        0       /* Seek from beginning of file.  */
+#  define SEEK_CUR        1       /* Seek from current position.  */
+#  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
+#endif
+
+#ifndef z_off_t
+#  define z_off_t long
+#endif
+
+#if !defined(_WIN32) && defined(Z_LARGE64)
+#  define z_off64_t off64_t
+#else
+#  if defined(_WIN32) && !defined(__GNUC__) && !defined(Z_SOLO)
+#    define z_off64_t __int64
+#  else
+#    define z_off64_t z_off_t
+#  endif
+#endif
+
+/* MVS linker does not support external names larger than 8 bytes */
+#if defined(__MVS__)
+  #pragma map(deflateInit_,"DEIN")
+  #pragma map(deflateInit2_,"DEIN2")
+  #pragma map(deflateEnd,"DEEND")
+  #pragma map(deflateBound,"DEBND")
+  #pragma map(inflateInit_,"ININ")
+  #pragma map(inflateInit2_,"ININ2")
+  #pragma map(inflateEnd,"INEND")
+  #pragma map(inflateSync,"INSY")
+  #pragma map(inflateSetDictionary,"INSEDI")
+  #pragma map(compressBound,"CMBND")
+  #pragma map(inflate_table,"INTABL")
+  #pragma map(inflate_fast,"INFA")
+  #pragma map(inflate_copyright,"INCOPY")
+#endif
+
+#endif /* ZCONF_H */
diff --git a/xs/src/png/zlib/zconf.h.in b/xs/src/png/zlib/zconf.h.in
new file mode 100644
index 000000000..5e1d68a00
--- /dev/null
+++ b/xs/src/png/zlib/zconf.h.in
@@ -0,0 +1,534 @@
+/* zconf.h -- configuration of the zlib compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZCONF_H
+#define ZCONF_H
+
+/*
+ * If you *really* need a unique prefix for all types and library functions,
+ * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
+ * Even better than compiling with -DZ_PREFIX would be to use configure to set
+ * this permanently in zconf.h using "./configure --zprefix".
+ */
+#ifdef Z_PREFIX     /* may be set to #if 1 by ./configure */
+#  define Z_PREFIX_SET
+
+/* all linked symbols and init macros */
+#  define _dist_code            z__dist_code
+#  define _length_code          z__length_code
+#  define _tr_align             z__tr_align
+#  define _tr_flush_bits        z__tr_flush_bits
+#  define _tr_flush_block       z__tr_flush_block
+#  define _tr_init              z__tr_init
+#  define _tr_stored_block      z__tr_stored_block
+#  define _tr_tally             z__tr_tally
+#  define adler32               z_adler32
+#  define adler32_combine       z_adler32_combine
+#  define adler32_combine64     z_adler32_combine64
+#  define adler32_z             z_adler32_z
+#  ifndef Z_SOLO
+#    define compress              z_compress
+#    define compress2             z_compress2
+#    define compressBound         z_compressBound
+#  endif
+#  define crc32                 z_crc32
+#  define crc32_combine         z_crc32_combine
+#  define crc32_combine64       z_crc32_combine64
+#  define crc32_z               z_crc32_z
+#  define deflate               z_deflate
+#  define deflateBound          z_deflateBound
+#  define deflateCopy           z_deflateCopy
+#  define deflateEnd            z_deflateEnd
+#  define deflateGetDictionary  z_deflateGetDictionary
+#  define deflateInit           z_deflateInit
+#  define deflateInit2          z_deflateInit2
+#  define deflateInit2_         z_deflateInit2_
+#  define deflateInit_          z_deflateInit_
+#  define deflateParams         z_deflateParams
+#  define deflatePending        z_deflatePending
+#  define deflatePrime          z_deflatePrime
+#  define deflateReset          z_deflateReset
+#  define deflateResetKeep      z_deflateResetKeep
+#  define deflateSetDictionary  z_deflateSetDictionary
+#  define deflateSetHeader      z_deflateSetHeader
+#  define deflateTune           z_deflateTune
+#  define deflate_copyright     z_deflate_copyright
+#  define get_crc_table         z_get_crc_table
+#  ifndef Z_SOLO
+#    define gz_error              z_gz_error
+#    define gz_intmax             z_gz_intmax
+#    define gz_strwinerror        z_gz_strwinerror
+#    define gzbuffer              z_gzbuffer
+#    define gzclearerr            z_gzclearerr
+#    define gzclose               z_gzclose
+#    define gzclose_r             z_gzclose_r
+#    define gzclose_w             z_gzclose_w
+#    define gzdirect              z_gzdirect
+#    define gzdopen               z_gzdopen
+#    define gzeof                 z_gzeof
+#    define gzerror               z_gzerror
+#    define gzflush               z_gzflush
+#    define gzfread               z_gzfread
+#    define gzfwrite              z_gzfwrite
+#    define gzgetc                z_gzgetc
+#    define gzgetc_               z_gzgetc_
+#    define gzgets                z_gzgets
+#    define gzoffset              z_gzoffset
+#    define gzoffset64            z_gzoffset64
+#    define gzopen                z_gzopen
+#    define gzopen64              z_gzopen64
+#    ifdef _WIN32
+#      define gzopen_w              z_gzopen_w
+#    endif
+#    define gzprintf              z_gzprintf
+#    define gzputc                z_gzputc
+#    define gzputs                z_gzputs
+#    define gzread                z_gzread
+#    define gzrewind              z_gzrewind
+#    define gzseek                z_gzseek
+#    define gzseek64              z_gzseek64
+#    define gzsetparams           z_gzsetparams
+#    define gztell                z_gztell
+#    define gztell64              z_gztell64
+#    define gzungetc              z_gzungetc
+#    define gzvprintf             z_gzvprintf
+#    define gzwrite               z_gzwrite
+#  endif
+#  define inflate               z_inflate
+#  define inflateBack           z_inflateBack
+#  define inflateBackEnd        z_inflateBackEnd
+#  define inflateBackInit       z_inflateBackInit
+#  define inflateBackInit_      z_inflateBackInit_
+#  define inflateCodesUsed      z_inflateCodesUsed
+#  define inflateCopy           z_inflateCopy
+#  define inflateEnd            z_inflateEnd
+#  define inflateGetDictionary  z_inflateGetDictionary
+#  define inflateGetHeader      z_inflateGetHeader
+#  define inflateInit           z_inflateInit
+#  define inflateInit2          z_inflateInit2
+#  define inflateInit2_         z_inflateInit2_
+#  define inflateInit_          z_inflateInit_
+#  define inflateMark           z_inflateMark
+#  define inflatePrime          z_inflatePrime
+#  define inflateReset          z_inflateReset
+#  define inflateReset2         z_inflateReset2
+#  define inflateResetKeep      z_inflateResetKeep
+#  define inflateSetDictionary  z_inflateSetDictionary
+#  define inflateSync           z_inflateSync
+#  define inflateSyncPoint      z_inflateSyncPoint
+#  define inflateUndermine      z_inflateUndermine
+#  define inflateValidate       z_inflateValidate
+#  define inflate_copyright     z_inflate_copyright
+#  define inflate_fast          z_inflate_fast
+#  define inflate_table         z_inflate_table
+#  ifndef Z_SOLO
+#    define uncompress            z_uncompress
+#    define uncompress2           z_uncompress2
+#  endif
+#  define zError                z_zError
+#  ifndef Z_SOLO
+#    define zcalloc               z_zcalloc
+#    define zcfree                z_zcfree
+#  endif
+#  define zlibCompileFlags      z_zlibCompileFlags
+#  define zlibVersion           z_zlibVersion
+
+/* all zlib typedefs in zlib.h and zconf.h */
+#  define Byte                  z_Byte
+#  define Bytef                 z_Bytef
+#  define alloc_func            z_alloc_func
+#  define charf                 z_charf
+#  define free_func             z_free_func
+#  ifndef Z_SOLO
+#    define gzFile                z_gzFile
+#  endif
+#  define gz_header             z_gz_header
+#  define gz_headerp            z_gz_headerp
+#  define in_func               z_in_func
+#  define intf                  z_intf
+#  define out_func              z_out_func
+#  define uInt                  z_uInt
+#  define uIntf                 z_uIntf
+#  define uLong                 z_uLong
+#  define uLongf                z_uLongf
+#  define voidp                 z_voidp
+#  define voidpc                z_voidpc
+#  define voidpf                z_voidpf
+
+/* all zlib structs in zlib.h and zconf.h */
+#  define gz_header_s           z_gz_header_s
+#  define internal_state        z_internal_state
+
+#endif
+
+#if defined(__MSDOS__) && !defined(MSDOS)
+#  define MSDOS
+#endif
+#if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
+#  define OS2
+#endif
+#if defined(_WINDOWS) && !defined(WINDOWS)
+#  define WINDOWS
+#endif
+#if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
+#  ifndef WIN32
+#    define WIN32
+#  endif
+#endif
+#if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
+#  if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
+#    ifndef SYS16BIT
+#      define SYS16BIT
+#    endif
+#  endif
+#endif
+
+/*
+ * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
+ * than 64k bytes at a time (needed on systems with 16-bit int).
+ */
+#ifdef SYS16BIT
+#  define MAXSEG_64K
+#endif
+#ifdef MSDOS
+#  define UNALIGNED_OK
+#endif
+
+#ifdef __STDC_VERSION__
+#  ifndef STDC
+#    define STDC
+#  endif
+#  if __STDC_VERSION__ >= 199901L
+#    ifndef STDC99
+#      define STDC99
+#    endif
+#  endif
+#endif
+#if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
+#  define STDC
+#endif
+
+#if defined(__OS400__) && !defined(STDC)    /* iSeries (formerly AS/400). */
+#  define STDC
+#endif
+
+#ifndef STDC
+#  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
+#    define const       /* note: need a more gentle solution here */
+#  endif
+#endif
+
+#if defined(ZLIB_CONST) && !defined(z_const)
+#  define z_const const
+#else
+#  define z_const
+#endif
+
+#ifdef Z_SOLO
+   typedef unsigned long z_size_t;
+#else
+#  define z_longlong long long
+#  if defined(NO_SIZE_T)
+     typedef unsigned NO_SIZE_T z_size_t;
+#  elif defined(STDC)
+#    include <stddef.h>
+     typedef size_t z_size_t;
+#  else
+     typedef unsigned long z_size_t;
+#  endif
+#  undef z_longlong
+#endif
+
+/* Maximum value for memLevel in deflateInit2 */
+#ifndef MAX_MEM_LEVEL
+#  ifdef MAXSEG_64K
+#    define MAX_MEM_LEVEL 8
+#  else
+#    define MAX_MEM_LEVEL 9
+#  endif
+#endif
+
+/* Maximum value for windowBits in deflateInit2 and inflateInit2.
+ * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
+ * created by gzip. (Files created by minigzip can still be extracted by
+ * gzip.)
+ */
+#ifndef MAX_WBITS
+#  define MAX_WBITS   15 /* 32K LZ77 window */
+#endif
+
+/* The memory requirements for deflate are (in bytes):
+            (1 << (windowBits+2)) +  (1 << (memLevel+9))
+ that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
+ plus a few kilobytes for small objects. For example, if you want to reduce
+ the default memory requirements from 256K to 128K, compile with
+     make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
+ Of course this will generally degrade compression (there's no free lunch).
+
+   The memory requirements for inflate are (in bytes) 1 << windowBits
+ that is, 32K for windowBits=15 (default value) plus about 7 kilobytes
+ for small objects.
+*/
+
+                        /* Type declarations */
+
+#ifndef OF /* function prototypes */
+#  ifdef STDC
+#    define OF(args)  args
+#  else
+#    define OF(args)  ()
+#  endif
+#endif
+
+#ifndef Z_ARG /* function prototypes for stdarg */
+#  if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#    define Z_ARG(args)  args
+#  else
+#    define Z_ARG(args)  ()
+#  endif
+#endif
+
+/* The following definitions for FAR are needed only for MSDOS mixed
+ * model programming (small or medium model with some far allocations).
+ * This was tested only with MSC; for other MSDOS compilers you may have
+ * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
+ * just define FAR to be empty.
+ */
+#ifdef SYS16BIT
+#  if defined(M_I86SM) || defined(M_I86MM)
+     /* MSC small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef _MSC_VER
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#  if (defined(__SMALL__) || defined(__MEDIUM__))
+     /* Turbo C small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef __BORLANDC__
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#endif
+
+#if defined(WINDOWS) || defined(WIN32)
+   /* If building or using zlib as a DLL, define ZLIB_DLL.
+    * This is not mandatory, but it offers a little performance increase.
+    */
+#  ifdef ZLIB_DLL
+#    if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
+#      ifdef ZLIB_INTERNAL
+#        define ZEXTERN extern __declspec(dllexport)
+#      else
+#        define ZEXTERN extern __declspec(dllimport)
+#      endif
+#    endif
+#  endif  /* ZLIB_DLL */
+   /* If building or using zlib with the WINAPI/WINAPIV calling convention,
+    * define ZLIB_WINAPI.
+    * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
+    */
+#  ifdef ZLIB_WINAPI
+#    ifdef FAR
+#      undef FAR
+#    endif
+#    include <windows.h>
+     /* No need for _export, use ZLIB.DEF instead. */
+     /* For complete Windows compatibility, use WINAPI, not __stdcall. */
+#    define ZEXPORT WINAPI
+#    ifdef WIN32
+#      define ZEXPORTVA WINAPIV
+#    else
+#      define ZEXPORTVA FAR CDECL
+#    endif
+#  endif
+#endif
+
+#if defined (__BEOS__)
+#  ifdef ZLIB_DLL
+#    ifdef ZLIB_INTERNAL
+#      define ZEXPORT   __declspec(dllexport)
+#      define ZEXPORTVA __declspec(dllexport)
+#    else
+#      define ZEXPORT   __declspec(dllimport)
+#      define ZEXPORTVA __declspec(dllimport)
+#    endif
+#  endif
+#endif
+
+#ifndef ZEXTERN
+#  define ZEXTERN extern
+#endif
+#ifndef ZEXPORT
+#  define ZEXPORT
+#endif
+#ifndef ZEXPORTVA
+#  define ZEXPORTVA
+#endif
+
+#ifndef FAR
+#  define FAR
+#endif
+
+#if !defined(__MACTYPES__)
+typedef unsigned char  Byte;  /* 8 bits */
+#endif
+typedef unsigned int   uInt;  /* 16 bits or more */
+typedef unsigned long  uLong; /* 32 bits or more */
+
+#ifdef SMALL_MEDIUM
+   /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
+#  define Bytef Byte FAR
+#else
+   typedef Byte  FAR Bytef;
+#endif
+typedef char  FAR charf;
+typedef int   FAR intf;
+typedef uInt  FAR uIntf;
+typedef uLong FAR uLongf;
+
+#ifdef STDC
+   typedef void const *voidpc;
+   typedef void FAR   *voidpf;
+   typedef void       *voidp;
+#else
+   typedef Byte const *voidpc;
+   typedef Byte FAR   *voidpf;
+   typedef Byte       *voidp;
+#endif
+
+#if !defined(Z_U4) && !defined(Z_SOLO) && defined(STDC)
+#  include <limits.h>
+#  if (UINT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned
+#  elif (ULONG_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned long
+#  elif (USHRT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned short
+#  endif
+#endif
+
+#ifdef Z_U4
+   typedef Z_U4 z_crc_t;
+#else
+   typedef unsigned long z_crc_t;
+#endif
+
+#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_UNISTD_H
+#endif
+
+#ifdef HAVE_STDARG_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_STDARG_H
+#endif
+
+#ifdef STDC
+#  ifndef Z_SOLO
+#    include <sys/types.h>      /* for off_t */
+#  endif
+#endif
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+#    include <stdarg.h>         /* for va_list */
+#  endif
+#endif
+
+#ifdef _WIN32
+#  ifndef Z_SOLO
+#    include <stddef.h>         /* for wchar_t */
+#  endif
+#endif
+
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if defined(_LARGEFILE64_SOURCE) && -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
+#if defined(__WATCOMC__) && !defined(Z_HAVE_UNISTD_H)
+#  define Z_HAVE_UNISTD_H
+#endif
+#ifndef Z_SOLO
+#  if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
+#    include <unistd.h>         /* for SEEK_*, off_t, and _LFS64_LARGEFILE */
+#    ifdef VMS
+#      include <unixio.h>       /* for off_t */
+#    endif
+#    ifndef z_off_t
+#      define z_off_t off_t
+#    endif
+#  endif
+#endif
+
+#if defined(_LFS64_LARGEFILE) && _LFS64_LARGEFILE-0
+#  define Z_LFS64
+#endif
+
+#if defined(_LARGEFILE64_SOURCE) && defined(Z_LFS64)
+#  define Z_LARGE64
+#endif
+
+#if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS-0 == 64 && defined(Z_LFS64)
+#  define Z_WANT64
+#endif
+
+#if !defined(SEEK_SET) && !defined(Z_SOLO)
+#  define SEEK_SET        0       /* Seek from beginning of file.  */
+#  define SEEK_CUR        1       /* Seek from current position.  */
+#  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
+#endif
+
+#ifndef z_off_t
+#  define z_off_t long
+#endif
+
+#if !defined(_WIN32) && defined(Z_LARGE64)
+#  define z_off64_t off64_t
+#else
+#  if defined(_WIN32) && !defined(__GNUC__) && !defined(Z_SOLO)
+#    define z_off64_t __int64
+#  else
+#    define z_off64_t z_off_t
+#  endif
+#endif
+
+/* MVS linker does not support external names larger than 8 bytes */
+#if defined(__MVS__)
+  #pragma map(deflateInit_,"DEIN")
+  #pragma map(deflateInit2_,"DEIN2")
+  #pragma map(deflateEnd,"DEEND")
+  #pragma map(deflateBound,"DEBND")
+  #pragma map(inflateInit_,"ININ")
+  #pragma map(inflateInit2_,"ININ2")
+  #pragma map(inflateEnd,"INEND")
+  #pragma map(inflateSync,"INSY")
+  #pragma map(inflateSetDictionary,"INSEDI")
+  #pragma map(compressBound,"CMBND")
+  #pragma map(inflate_table,"INTABL")
+  #pragma map(inflate_fast,"INFA")
+  #pragma map(inflate_copyright,"INCOPY")
+#endif
+
+#endif /* ZCONF_H */
diff --git a/xs/src/png/zlib/zconf.h.included b/xs/src/png/zlib/zconf.h.included
new file mode 100644
index 000000000..5e1d68a00
--- /dev/null
+++ b/xs/src/png/zlib/zconf.h.included
@@ -0,0 +1,534 @@
+/* zconf.h -- configuration of the zlib compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZCONF_H
+#define ZCONF_H
+
+/*
+ * If you *really* need a unique prefix for all types and library functions,
+ * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
+ * Even better than compiling with -DZ_PREFIX would be to use configure to set
+ * this permanently in zconf.h using "./configure --zprefix".
+ */
+#ifdef Z_PREFIX     /* may be set to #if 1 by ./configure */
+#  define Z_PREFIX_SET
+
+/* all linked symbols and init macros */
+#  define _dist_code            z__dist_code
+#  define _length_code          z__length_code
+#  define _tr_align             z__tr_align
+#  define _tr_flush_bits        z__tr_flush_bits
+#  define _tr_flush_block       z__tr_flush_block
+#  define _tr_init              z__tr_init
+#  define _tr_stored_block      z__tr_stored_block
+#  define _tr_tally             z__tr_tally
+#  define adler32               z_adler32
+#  define adler32_combine       z_adler32_combine
+#  define adler32_combine64     z_adler32_combine64
+#  define adler32_z             z_adler32_z
+#  ifndef Z_SOLO
+#    define compress              z_compress
+#    define compress2             z_compress2
+#    define compressBound         z_compressBound
+#  endif
+#  define crc32                 z_crc32
+#  define crc32_combine         z_crc32_combine
+#  define crc32_combine64       z_crc32_combine64
+#  define crc32_z               z_crc32_z
+#  define deflate               z_deflate
+#  define deflateBound          z_deflateBound
+#  define deflateCopy           z_deflateCopy
+#  define deflateEnd            z_deflateEnd
+#  define deflateGetDictionary  z_deflateGetDictionary
+#  define deflateInit           z_deflateInit
+#  define deflateInit2          z_deflateInit2
+#  define deflateInit2_         z_deflateInit2_
+#  define deflateInit_          z_deflateInit_
+#  define deflateParams         z_deflateParams
+#  define deflatePending        z_deflatePending
+#  define deflatePrime          z_deflatePrime
+#  define deflateReset          z_deflateReset
+#  define deflateResetKeep      z_deflateResetKeep
+#  define deflateSetDictionary  z_deflateSetDictionary
+#  define deflateSetHeader      z_deflateSetHeader
+#  define deflateTune           z_deflateTune
+#  define deflate_copyright     z_deflate_copyright
+#  define get_crc_table         z_get_crc_table
+#  ifndef Z_SOLO
+#    define gz_error              z_gz_error
+#    define gz_intmax             z_gz_intmax
+#    define gz_strwinerror        z_gz_strwinerror
+#    define gzbuffer              z_gzbuffer
+#    define gzclearerr            z_gzclearerr
+#    define gzclose               z_gzclose
+#    define gzclose_r             z_gzclose_r
+#    define gzclose_w             z_gzclose_w
+#    define gzdirect              z_gzdirect
+#    define gzdopen               z_gzdopen
+#    define gzeof                 z_gzeof
+#    define gzerror               z_gzerror
+#    define gzflush               z_gzflush
+#    define gzfread               z_gzfread
+#    define gzfwrite              z_gzfwrite
+#    define gzgetc                z_gzgetc
+#    define gzgetc_               z_gzgetc_
+#    define gzgets                z_gzgets
+#    define gzoffset              z_gzoffset
+#    define gzoffset64            z_gzoffset64
+#    define gzopen                z_gzopen
+#    define gzopen64              z_gzopen64
+#    ifdef _WIN32
+#      define gzopen_w              z_gzopen_w
+#    endif
+#    define gzprintf              z_gzprintf
+#    define gzputc                z_gzputc
+#    define gzputs                z_gzputs
+#    define gzread                z_gzread
+#    define gzrewind              z_gzrewind
+#    define gzseek                z_gzseek
+#    define gzseek64              z_gzseek64
+#    define gzsetparams           z_gzsetparams
+#    define gztell                z_gztell
+#    define gztell64              z_gztell64
+#    define gzungetc              z_gzungetc
+#    define gzvprintf             z_gzvprintf
+#    define gzwrite               z_gzwrite
+#  endif
+#  define inflate               z_inflate
+#  define inflateBack           z_inflateBack
+#  define inflateBackEnd        z_inflateBackEnd
+#  define inflateBackInit       z_inflateBackInit
+#  define inflateBackInit_      z_inflateBackInit_
+#  define inflateCodesUsed      z_inflateCodesUsed
+#  define inflateCopy           z_inflateCopy
+#  define inflateEnd            z_inflateEnd
+#  define inflateGetDictionary  z_inflateGetDictionary
+#  define inflateGetHeader      z_inflateGetHeader
+#  define inflateInit           z_inflateInit
+#  define inflateInit2          z_inflateInit2
+#  define inflateInit2_         z_inflateInit2_
+#  define inflateInit_          z_inflateInit_
+#  define inflateMark           z_inflateMark
+#  define inflatePrime          z_inflatePrime
+#  define inflateReset          z_inflateReset
+#  define inflateReset2         z_inflateReset2
+#  define inflateResetKeep      z_inflateResetKeep
+#  define inflateSetDictionary  z_inflateSetDictionary
+#  define inflateSync           z_inflateSync
+#  define inflateSyncPoint      z_inflateSyncPoint
+#  define inflateUndermine      z_inflateUndermine
+#  define inflateValidate       z_inflateValidate
+#  define inflate_copyright     z_inflate_copyright
+#  define inflate_fast          z_inflate_fast
+#  define inflate_table         z_inflate_table
+#  ifndef Z_SOLO
+#    define uncompress            z_uncompress
+#    define uncompress2           z_uncompress2
+#  endif
+#  define zError                z_zError
+#  ifndef Z_SOLO
+#    define zcalloc               z_zcalloc
+#    define zcfree                z_zcfree
+#  endif
+#  define zlibCompileFlags      z_zlibCompileFlags
+#  define zlibVersion           z_zlibVersion
+
+/* all zlib typedefs in zlib.h and zconf.h */
+#  define Byte                  z_Byte
+#  define Bytef                 z_Bytef
+#  define alloc_func            z_alloc_func
+#  define charf                 z_charf
+#  define free_func             z_free_func
+#  ifndef Z_SOLO
+#    define gzFile                z_gzFile
+#  endif
+#  define gz_header             z_gz_header
+#  define gz_headerp            z_gz_headerp
+#  define in_func               z_in_func
+#  define intf                  z_intf
+#  define out_func              z_out_func
+#  define uInt                  z_uInt
+#  define uIntf                 z_uIntf
+#  define uLong                 z_uLong
+#  define uLongf                z_uLongf
+#  define voidp                 z_voidp
+#  define voidpc                z_voidpc
+#  define voidpf                z_voidpf
+
+/* all zlib structs in zlib.h and zconf.h */
+#  define gz_header_s           z_gz_header_s
+#  define internal_state        z_internal_state
+
+#endif
+
+#if defined(__MSDOS__) && !defined(MSDOS)
+#  define MSDOS
+#endif
+#if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
+#  define OS2
+#endif
+#if defined(_WINDOWS) && !defined(WINDOWS)
+#  define WINDOWS
+#endif
+#if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
+#  ifndef WIN32
+#    define WIN32
+#  endif
+#endif
+#if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
+#  if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
+#    ifndef SYS16BIT
+#      define SYS16BIT
+#    endif
+#  endif
+#endif
+
+/*
+ * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
+ * than 64k bytes at a time (needed on systems with 16-bit int).
+ */
+#ifdef SYS16BIT
+#  define MAXSEG_64K
+#endif
+#ifdef MSDOS
+#  define UNALIGNED_OK
+#endif
+
+#ifdef __STDC_VERSION__
+#  ifndef STDC
+#    define STDC
+#  endif
+#  if __STDC_VERSION__ >= 199901L
+#    ifndef STDC99
+#      define STDC99
+#    endif
+#  endif
+#endif
+#if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
+#  define STDC
+#endif
+
+#if defined(__OS400__) && !defined(STDC)    /* iSeries (formerly AS/400). */
+#  define STDC
+#endif
+
+#ifndef STDC
+#  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
+#    define const       /* note: need a more gentle solution here */
+#  endif
+#endif
+
+#if defined(ZLIB_CONST) && !defined(z_const)
+#  define z_const const
+#else
+#  define z_const
+#endif
+
+#ifdef Z_SOLO
+   typedef unsigned long z_size_t;
+#else
+#  define z_longlong long long
+#  if defined(NO_SIZE_T)
+     typedef unsigned NO_SIZE_T z_size_t;
+#  elif defined(STDC)
+#    include <stddef.h>
+     typedef size_t z_size_t;
+#  else
+     typedef unsigned long z_size_t;
+#  endif
+#  undef z_longlong
+#endif
+
+/* Maximum value for memLevel in deflateInit2 */
+#ifndef MAX_MEM_LEVEL
+#  ifdef MAXSEG_64K
+#    define MAX_MEM_LEVEL 8
+#  else
+#    define MAX_MEM_LEVEL 9
+#  endif
+#endif
+
+/* Maximum value for windowBits in deflateInit2 and inflateInit2.
+ * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
+ * created by gzip. (Files created by minigzip can still be extracted by
+ * gzip.)
+ */
+#ifndef MAX_WBITS
+#  define MAX_WBITS   15 /* 32K LZ77 window */
+#endif
+
+/* The memory requirements for deflate are (in bytes):
+            (1 << (windowBits+2)) +  (1 << (memLevel+9))
+ that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
+ plus a few kilobytes for small objects. For example, if you want to reduce
+ the default memory requirements from 256K to 128K, compile with
+     make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
+ Of course this will generally degrade compression (there's no free lunch).
+
+   The memory requirements for inflate are (in bytes) 1 << windowBits
+ that is, 32K for windowBits=15 (default value) plus about 7 kilobytes
+ for small objects.
+*/
+
+                        /* Type declarations */
+
+#ifndef OF /* function prototypes */
+#  ifdef STDC
+#    define OF(args)  args
+#  else
+#    define OF(args)  ()
+#  endif
+#endif
+
+#ifndef Z_ARG /* function prototypes for stdarg */
+#  if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#    define Z_ARG(args)  args
+#  else
+#    define Z_ARG(args)  ()
+#  endif
+#endif
+
+/* The following definitions for FAR are needed only for MSDOS mixed
+ * model programming (small or medium model with some far allocations).
+ * This was tested only with MSC; for other MSDOS compilers you may have
+ * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
+ * just define FAR to be empty.
+ */
+#ifdef SYS16BIT
+#  if defined(M_I86SM) || defined(M_I86MM)
+     /* MSC small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef _MSC_VER
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#  if (defined(__SMALL__) || defined(__MEDIUM__))
+     /* Turbo C small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef __BORLANDC__
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#endif
+
+#if defined(WINDOWS) || defined(WIN32)
+   /* If building or using zlib as a DLL, define ZLIB_DLL.
+    * This is not mandatory, but it offers a little performance increase.
+    */
+#  ifdef ZLIB_DLL
+#    if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
+#      ifdef ZLIB_INTERNAL
+#        define ZEXTERN extern __declspec(dllexport)
+#      else
+#        define ZEXTERN extern __declspec(dllimport)
+#      endif
+#    endif
+#  endif  /* ZLIB_DLL */
+   /* If building or using zlib with the WINAPI/WINAPIV calling convention,
+    * define ZLIB_WINAPI.
+    * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
+    */
+#  ifdef ZLIB_WINAPI
+#    ifdef FAR
+#      undef FAR
+#    endif
+#    include <windows.h>
+     /* No need for _export, use ZLIB.DEF instead. */
+     /* For complete Windows compatibility, use WINAPI, not __stdcall. */
+#    define ZEXPORT WINAPI
+#    ifdef WIN32
+#      define ZEXPORTVA WINAPIV
+#    else
+#      define ZEXPORTVA FAR CDECL
+#    endif
+#  endif
+#endif
+
+#if defined (__BEOS__)
+#  ifdef ZLIB_DLL
+#    ifdef ZLIB_INTERNAL
+#      define ZEXPORT   __declspec(dllexport)
+#      define ZEXPORTVA __declspec(dllexport)
+#    else
+#      define ZEXPORT   __declspec(dllimport)
+#      define ZEXPORTVA __declspec(dllimport)
+#    endif
+#  endif
+#endif
+
+#ifndef ZEXTERN
+#  define ZEXTERN extern
+#endif
+#ifndef ZEXPORT
+#  define ZEXPORT
+#endif
+#ifndef ZEXPORTVA
+#  define ZEXPORTVA
+#endif
+
+#ifndef FAR
+#  define FAR
+#endif
+
+#if !defined(__MACTYPES__)
+typedef unsigned char  Byte;  /* 8 bits */
+#endif
+typedef unsigned int   uInt;  /* 16 bits or more */
+typedef unsigned long  uLong; /* 32 bits or more */
+
+#ifdef SMALL_MEDIUM
+   /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
+#  define Bytef Byte FAR
+#else
+   typedef Byte  FAR Bytef;
+#endif
+typedef char  FAR charf;
+typedef int   FAR intf;
+typedef uInt  FAR uIntf;
+typedef uLong FAR uLongf;
+
+#ifdef STDC
+   typedef void const *voidpc;
+   typedef void FAR   *voidpf;
+   typedef void       *voidp;
+#else
+   typedef Byte const *voidpc;
+   typedef Byte FAR   *voidpf;
+   typedef Byte       *voidp;
+#endif
+
+#if !defined(Z_U4) && !defined(Z_SOLO) && defined(STDC)
+#  include <limits.h>
+#  if (UINT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned
+#  elif (ULONG_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned long
+#  elif (USHRT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned short
+#  endif
+#endif
+
+#ifdef Z_U4
+   typedef Z_U4 z_crc_t;
+#else
+   typedef unsigned long z_crc_t;
+#endif
+
+#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_UNISTD_H
+#endif
+
+#ifdef HAVE_STDARG_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_STDARG_H
+#endif
+
+#ifdef STDC
+#  ifndef Z_SOLO
+#    include <sys/types.h>      /* for off_t */
+#  endif
+#endif
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+#    include <stdarg.h>         /* for va_list */
+#  endif
+#endif
+
+#ifdef _WIN32
+#  ifndef Z_SOLO
+#    include <stddef.h>         /* for wchar_t */
+#  endif
+#endif
+
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if defined(_LARGEFILE64_SOURCE) && -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
+#if defined(__WATCOMC__) && !defined(Z_HAVE_UNISTD_H)
+#  define Z_HAVE_UNISTD_H
+#endif
+#ifndef Z_SOLO
+#  if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
+#    include <unistd.h>         /* for SEEK_*, off_t, and _LFS64_LARGEFILE */
+#    ifdef VMS
+#      include <unixio.h>       /* for off_t */
+#    endif
+#    ifndef z_off_t
+#      define z_off_t off_t
+#    endif
+#  endif
+#endif
+
+#if defined(_LFS64_LARGEFILE) && _LFS64_LARGEFILE-0
+#  define Z_LFS64
+#endif
+
+#if defined(_LARGEFILE64_SOURCE) && defined(Z_LFS64)
+#  define Z_LARGE64
+#endif
+
+#if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS-0 == 64 && defined(Z_LFS64)
+#  define Z_WANT64
+#endif
+
+#if !defined(SEEK_SET) && !defined(Z_SOLO)
+#  define SEEK_SET        0       /* Seek from beginning of file.  */
+#  define SEEK_CUR        1       /* Seek from current position.  */
+#  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
+#endif
+
+#ifndef z_off_t
+#  define z_off_t long
+#endif
+
+#if !defined(_WIN32) && defined(Z_LARGE64)
+#  define z_off64_t off64_t
+#else
+#  if defined(_WIN32) && !defined(__GNUC__) && !defined(Z_SOLO)
+#    define z_off64_t __int64
+#  else
+#    define z_off64_t z_off_t
+#  endif
+#endif
+
+/* MVS linker does not support external names larger than 8 bytes */
+#if defined(__MVS__)
+  #pragma map(deflateInit_,"DEIN")
+  #pragma map(deflateInit2_,"DEIN2")
+  #pragma map(deflateEnd,"DEEND")
+  #pragma map(deflateBound,"DEBND")
+  #pragma map(inflateInit_,"ININ")
+  #pragma map(inflateInit2_,"ININ2")
+  #pragma map(inflateEnd,"INEND")
+  #pragma map(inflateSync,"INSY")
+  #pragma map(inflateSetDictionary,"INSEDI")
+  #pragma map(compressBound,"CMBND")
+  #pragma map(inflate_table,"INTABL")
+  #pragma map(inflate_fast,"INFA")
+  #pragma map(inflate_copyright,"INCOPY")
+#endif
+
+#endif /* ZCONF_H */
diff --git a/xs/src/png/zlib/zlib.3 b/xs/src/png/zlib/zlib.3
new file mode 100644
index 000000000..bda4eb073
--- /dev/null
+++ b/xs/src/png/zlib/zlib.3
@@ -0,0 +1,149 @@
+.TH ZLIB 3 "15 Jan 2017"
+.SH NAME
+zlib \- compression/decompression library
+.SH SYNOPSIS
+[see
+.I zlib.h
+for full description]
+.SH DESCRIPTION
+The
+.I zlib
+library is a general purpose data compression library.
+The code is thread safe, assuming that the standard library functions
+used are thread safe, such as memory allocation routines.
+It provides in-memory compression and decompression functions,
+including integrity checks of the uncompressed data.
+This version of the library supports only one compression method (deflation)
+but other algorithms may be added later
+with the same stream interface.
+.LP
+Compression can be done in a single step if the buffers are large enough
+or can be done by repeated calls of the compression function.
+In the latter case,
+the application must provide more input and/or consume the output
+(providing more output space) before each call.
+.LP
+The library also supports reading and writing files in
+.IR gzip (1)
+(.gz) format
+with an interface similar to that of stdio.
+.LP
+The library does not install any signal handler.
+The decoder checks the consistency of the compressed data,
+so the library should never crash even in the case of corrupted input.
+.LP
+All functions of the compression library are documented in the file
+.IR zlib.h .
+The distribution source includes examples of use of the library
+in the files
+.I test/example.c
+and
+.IR test/minigzip.c,
+as well as other examples in the
+.IR examples/
+directory.
+.LP
+Changes to this version are documented in the file
+.I ChangeLog
+that accompanies the source.
+.LP
+.I zlib
+is built in to many languages and operating systems, including but not limited to
+Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go.
+.LP
+An experimental package to read and write files in the .zip format,
+written on top of
+.I zlib
+by Gilles Vollant (info@winimage.com),
+is available at:
+.IP
+http://www.winimage.com/zLibDll/minizip.html
+and also in the
+.I contrib/minizip
+directory of the main
+.I zlib
+source distribution.
+.SH "SEE ALSO"
+The
+.I zlib
+web site can be found at:
+.IP
+http://zlib.net/
+.LP
+The data format used by the
+.I zlib
+library is described by RFC
+(Request for Comments) 1950 to 1952 in the files:
+.IP
+http://tools.ietf.org/html/rfc1950 (for the zlib header and trailer format)
+.br
+http://tools.ietf.org/html/rfc1951 (for the deflate compressed data format)
+.br
+http://tools.ietf.org/html/rfc1952 (for the gzip header and trailer format)
+.LP
+Mark Nelson wrote an article about
+.I zlib
+for the Jan. 1997 issue of  Dr. Dobb's Journal;
+a copy of the article is available at:
+.IP
+http://marknelson.us/1997/01/01/zlib-engine/
+.SH "REPORTING PROBLEMS"
+Before reporting a problem,
+please check the
+.I zlib
+web site to verify that you have the latest version of
+.IR zlib ;
+otherwise,
+obtain the latest version and see if the problem still exists.
+Please read the
+.I zlib
+FAQ at:
+.IP
+http://zlib.net/zlib_faq.html
+.LP
+before asking for help.
+Send questions and/or comments to zlib@gzip.org,
+or (for the Windows DLL version) to Gilles Vollant (info@winimage.com).
+.SH AUTHORS AND LICENSE
+Version 1.2.11
+.LP
+Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+.LP
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+.LP
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+.LP
+.nr step 1 1
+.IP \n[step]. 3
+The origin of this software must not be misrepresented; you must not
+claim that you wrote the original software. If you use this software
+in a product, an acknowledgment in the product documentation would be
+appreciated but is not required.
+.IP \n+[step].
+Altered source versions must be plainly marked as such, and must not be
+misrepresented as being the original software.
+.IP \n+[step].
+This notice may not be removed or altered from any source distribution.
+.LP
+Jean-loup Gailly        Mark Adler
+.br
+jloup@gzip.org          madler@alumni.caltech.edu
+.LP
+The deflate format used by
+.I zlib
+was defined by Phil Katz.
+The deflate and
+.I zlib
+specifications were written by L. Peter Deutsch.
+Thanks to all the people who reported problems and suggested various
+improvements in
+.IR zlib ;
+who are too numerous to cite here.
+.LP
+UNIX manual page by R. P. C. Rodgers,
+U.S. National Library of Medicine (rodgers@nlm.nih.gov).
+.\" end of man page
diff --git a/xs/src/png/zlib/zlib.3.pdf b/xs/src/png/zlib/zlib.3.pdf
new file mode 100644
index 000000000..6fa519c5b
--- /dev/null
+++ b/xs/src/png/zlib/zlib.3.pdf
diff --git a/xs/src/png/zlib/zlib.h b/xs/src/png/zlib/zlib.h
new file mode 100644
index 000000000..f09cdaf1e
--- /dev/null
+++ b/xs/src/png/zlib/zlib.h
@@ -0,0 +1,1912 @@
+/* zlib.h -- interface of the 'zlib' general purpose compression library
+  version 1.2.11, January 15th, 2017
+
+  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+
+  The data format used by the zlib library is described by RFCs (Request for
+  Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
+  (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
+*/
+
+#ifndef ZLIB_H
+#define ZLIB_H
+
+#include "zconf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZLIB_VERSION "1.2.11"
+#define ZLIB_VERNUM 0x12b0
+#define ZLIB_VER_MAJOR 1
+#define ZLIB_VER_MINOR 2
+#define ZLIB_VER_REVISION 11
+#define ZLIB_VER_SUBREVISION 0
+
+/*
+    The 'zlib' compression library provides in-memory compression and
+  decompression functions, including integrity checks of the uncompressed data.
+  This version of the library supports only one compression method (deflation)
+  but other algorithms will be added later and will have the same stream
+  interface.
+
+    Compression can be done in a single step if the buffers are large enough,
+  or can be done by repeated calls of the compression function.  In the latter
+  case, the application must provide more input and/or consume the output
+  (providing more output space) before each call.
+
+    The compressed data format used by default by the in-memory functions is
+  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
+  around a deflate stream, which is itself documented in RFC 1951.
+
+    The library also supports reading and writing files in gzip (.gz) format
+  with an interface similar to that of stdio using the functions that start
+  with "gz".  The gzip format is different from the zlib format.  gzip is a
+  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
+
+    This library can optionally read and write gzip and raw deflate streams in
+  memory as well.
+
+    The zlib format was designed to be compact and fast for use in memory
+  and on communications channels.  The gzip format was designed for single-
+  file compression on file systems, has a larger header than zlib to maintain
+  directory information, and uses a different, slower check method than zlib.
+
+    The library does not install any signal handler.  The decoder checks
+  the consistency of the compressed data, so the library should never crash
+  even in the case of corrupted input.
+*/
+
+typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
+typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
+
+struct internal_state;
+
+typedef struct z_stream_s {
+    z_const Bytef *next_in;     /* next input byte */
+    uInt     avail_in;  /* number of bytes available at next_in */
+    uLong    total_in;  /* total number of input bytes read so far */
+
+    Bytef    *next_out; /* next output byte will go here */
+    uInt     avail_out; /* remaining free space at next_out */
+    uLong    total_out; /* total number of bytes output so far */
+
+    z_const char *msg;  /* last error message, NULL if no error */
+    struct internal_state FAR *state; /* not visible by applications */
+
+    alloc_func zalloc;  /* used to allocate the internal state */
+    free_func  zfree;   /* used to free the internal state */
+    voidpf     opaque;  /* private data object passed to zalloc and zfree */
+
+    int     data_type;  /* best guess about the data type: binary or text
+                           for deflate, or the decoding state for inflate */
+    uLong   adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
+    uLong   reserved;   /* reserved for future use */
+} z_stream;
+
+typedef z_stream FAR *z_streamp;
+
+/*
+     gzip header information passed to and from zlib routines.  See RFC 1952
+  for more details on the meanings of these fields.
+*/
+typedef struct gz_header_s {
+    int     text;       /* true if compressed data believed to be text */
+    uLong   time;       /* modification time */
+    int     xflags;     /* extra flags (not used when writing a gzip file) */
+    int     os;         /* operating system */
+    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
+    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
+    uInt    extra_max;  /* space at extra (only when reading header) */
+    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
+    uInt    name_max;   /* space at name (only when reading header) */
+    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
+    uInt    comm_max;   /* space at comment (only when reading header) */
+    int     hcrc;       /* true if there was or will be a header crc */
+    int     done;       /* true when done reading gzip header (not used
+                           when writing a gzip file) */
+} gz_header;
+
+typedef gz_header FAR *gz_headerp;
+
+/*
+     The application must update next_in and avail_in when avail_in has dropped
+   to zero.  It must update next_out and avail_out when avail_out has dropped
+   to zero.  The application must initialize zalloc, zfree and opaque before
+   calling the init function.  All other fields are set by the compression
+   library and must not be updated by the application.
+
+     The opaque value provided by the application will be passed as the first
+   parameter for calls of zalloc and zfree.  This can be useful for custom
+   memory management.  The compression library attaches no meaning to the
+   opaque value.
+
+     zalloc must return Z_NULL if there is not enough memory for the object.
+   If zlib is used in a multi-threaded application, zalloc and zfree must be
+   thread safe.  In that case, zlib is thread-safe.  When zalloc and zfree are
+   Z_NULL on entry to the initialization function, they are set to internal
+   routines that use the standard library functions malloc() and free().
+
+     On 16-bit systems, the functions zalloc and zfree must be able to allocate
+   exactly 65536 bytes, but will not be required to allocate more than this if
+   the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
+   returned by zalloc for objects of exactly 65536 bytes *must* have their
+   offset normalized to zero.  The default allocation function provided by this
+   library ensures this (see zutil.c).  To reduce memory requirements and avoid
+   any allocation of 64K objects, at the expense of compression ratio, compile
+   the library with -DMAX_WBITS=14 (see zconf.h).
+
+     The fields total_in and total_out can be used for statistics or progress
+   reports.  After compression, total_in holds the total size of the
+   uncompressed data and may be saved for use by the decompressor (particularly
+   if the decompressor wants to decompress everything in a single step).
+*/
+
+                        /* constants */
+
+#define Z_NO_FLUSH      0
+#define Z_PARTIAL_FLUSH 1
+#define Z_SYNC_FLUSH    2
+#define Z_FULL_FLUSH    3
+#define Z_FINISH        4
+#define Z_BLOCK         5
+#define Z_TREES         6
+/* Allowed flush values; see deflate() and inflate() below for details */
+
+#define Z_OK            0
+#define Z_STREAM_END    1
+#define Z_NEED_DICT     2
+#define Z_ERRNO        (-1)
+#define Z_STREAM_ERROR (-2)
+#define Z_DATA_ERROR   (-3)
+#define Z_MEM_ERROR    (-4)
+#define Z_BUF_ERROR    (-5)
+#define Z_VERSION_ERROR (-6)
+/* Return codes for the compression/decompression functions. Negative values
+ * are errors, positive values are used for special but normal events.
+ */
+
+#define Z_NO_COMPRESSION         0
+#define Z_BEST_SPEED             1
+#define Z_BEST_COMPRESSION       9
+#define Z_DEFAULT_COMPRESSION  (-1)
+/* compression levels */
+
+#define Z_FILTERED            1
+#define Z_HUFFMAN_ONLY        2
+#define Z_RLE                 3
+#define Z_FIXED               4
+#define Z_DEFAULT_STRATEGY    0
+/* compression strategy; see deflateInit2() below for details */
+
+#define Z_BINARY   0
+#define Z_TEXT     1
+#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
+#define Z_UNKNOWN  2
+/* Possible values of the data_type field for deflate() */
+
+#define Z_DEFLATED   8
+/* The deflate compression method (the only one supported in this version) */
+
+#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
+
+#define zlib_version zlibVersion()
+/* for compatibility with versions < 1.0.2 */
+
+
+                        /* basic functions */
+
+ZEXTERN const char * ZEXPORT zlibVersion OF((void));
+/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
+   If the first character differs, the library code actually used is not
+   compatible with the zlib.h header file used by the application.  This check
+   is automatically made by deflateInit and inflateInit.
+ */
+
+/*
+ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
+
+     Initializes the internal stream state for compression.  The fields
+   zalloc, zfree and opaque must be initialized before by the caller.  If
+   zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
+   allocation functions.
+
+     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
+   1 gives best speed, 9 gives best compression, 0 gives no compression at all
+   (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
+   requests a default compromise between speed and compression (currently
+   equivalent to level 6).
+
+     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if level is not a valid compression level, or
+   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
+   with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
+   if there is no error message.  deflateInit does not perform any compression:
+   this will be done by deflate().
+*/
+
+
+ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
+/*
+    deflate compresses as much data as possible, and stops when the input
+  buffer becomes empty or the output buffer becomes full.  It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
+
+    The detailed semantics are as follows.  deflate performs one or both of the
+  following actions:
+
+  - Compress more input starting at next_in and update next_in and avail_in
+    accordingly.  If not all input can be processed (because there is not
+    enough room in the output buffer), next_in and avail_in are updated and
+    processing will resume at this point for the next call of deflate().
+
+  - Generate more output starting at next_out and update next_out and avail_out
+    accordingly.  This action is forced if the parameter flush is non zero.
+    Forcing flush frequently degrades the compression ratio, so this parameter
+    should be set only when necessary.  Some output may be provided even if
+    flush is zero.
+
+    Before the call of deflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming more
+  output, and updating avail_in or avail_out accordingly; avail_out should
+  never be zero before the call.  The application can consume the compressed
+  output when it wants, for example when the output buffer is full (avail_out
+  == 0), or after each call of deflate().  If deflate returns Z_OK and with
+  zero avail_out, it must be called again after making room in the output
+  buffer because there might be more output pending. See deflatePending(),
+  which can be used if desired to determine whether or not there is more ouput
+  in that case.
+
+    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
+  decide how much data to accumulate before producing output, in order to
+  maximize compression.
+
+    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
+  flushed to the output buffer and the output is aligned on a byte boundary, so
+  that the decompressor can get all input data available so far.  (In
+  particular avail_in is zero after the call if enough output space has been
+  provided before the call.) Flushing may degrade compression for some
+  compression algorithms and so it should be used only when necessary.  This
+  completes the current deflate block and follows it with an empty stored block
+  that is three bits plus filler bits to the next byte, followed by four bytes
+  (00 00 ff ff).
+
+    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
+  output buffer, but the output is not aligned to a byte boundary.  All of the
+  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
+  This completes the current deflate block and follows it with an empty fixed
+  codes block that is 10 bits long.  This assures that enough bytes are output
+  in order for the decompressor to finish the block before the empty fixed
+  codes block.
+
+    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
+  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
+  seven bits of the current block are held to be written as the next byte after
+  the next deflate block is completed.  In this case, the decompressor may not
+  be provided enough bits at this point in order to complete decompression of
+  the data provided so far to the compressor.  It may need to wait for the next
+  block to be emitted.  This is for advanced applications that need to control
+  the emission of deflate blocks.
+
+    If flush is set to Z_FULL_FLUSH, all output is flushed as with
+  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
+  restart from this point if previous compressed data has been damaged or if
+  random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
+  compression.
+
+    If deflate returns with avail_out == 0, this function must be called again
+  with the same value of the flush parameter and more output space (updated
+  avail_out), until the flush is complete (deflate returns with non-zero
+  avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
+  avail_out is greater than six to avoid repeated flush markers due to
+  avail_out == 0 on return.
+
+    If the parameter flush is set to Z_FINISH, pending input is processed,
+  pending output is flushed and deflate returns with Z_STREAM_END if there was
+  enough output space.  If deflate returns with Z_OK or Z_BUF_ERROR, this
+  function must be called again with Z_FINISH and more output space (updated
+  avail_out) but no more input data, until it returns with Z_STREAM_END or an
+  error.  After deflate has returned Z_STREAM_END, the only possible operations
+  on the stream are deflateReset or deflateEnd.
+
+    Z_FINISH can be used in the first deflate call after deflateInit if all the
+  compression is to be done in a single step.  In order to complete in one
+  call, avail_out must be at least the value returned by deflateBound (see
+  below).  Then deflate is guaranteed to return Z_STREAM_END.  If not enough
+  output space is provided, deflate will not return Z_STREAM_END, and it must
+  be called again as described above.
+
+    deflate() sets strm->adler to the Adler-32 checksum of all input read
+  so far (that is, total_in bytes).  If a gzip stream is being generated, then
+  strm->adler will be the CRC-32 checksum of the input read so far.  (See
+  deflateInit2 below.)
+
+    deflate() may update strm->data_type if it can make a good guess about
+  the input data type (Z_BINARY or Z_TEXT).  If in doubt, the data is
+  considered binary.  This field is only for information purposes and does not
+  affect the compression algorithm in any manner.
+
+    deflate() returns Z_OK if some progress has been made (more input
+  processed or more output produced), Z_STREAM_END if all input has been
+  consumed and all output has been produced (only when flush is set to
+  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
+  if next_in or next_out was Z_NULL or the state was inadvertently written over
+  by the application), or Z_BUF_ERROR if no progress is possible (for example
+  avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not fatal, and
+  deflate() can be called again with more input and more output space to
+  continue compressing.
+*/
+
+
+ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any pending
+   output.
+
+     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
+   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
+   prematurely (some input or output was discarded).  In the error case, msg
+   may be set but then points to a static string (which must not be
+   deallocated).
+*/
+
+
+/*
+ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
+
+     Initializes the internal stream state for decompression.  The fields
+   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
+   the caller.  In the current version of inflate, the provided input is not
+   read or consumed.  The allocation of a sliding window will be deferred to
+   the first call of inflate (if the decompression does not complete on the
+   first call).  If zalloc and zfree are set to Z_NULL, inflateInit updates
+   them to use default allocation functions.
+
+     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
+   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
+   invalid, such as a null pointer to the structure.  msg is set to null if
+   there is no error message.  inflateInit does not perform any decompression.
+   Actual decompression will be done by inflate().  So next_in, and avail_in,
+   next_out, and avail_out are unused and unchanged.  The current
+   implementation of inflateInit() does not process any header information --
+   that is deferred until inflate() is called.
+*/
+
+
+ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
+/*
+    inflate decompresses as much data as possible, and stops when the input
+  buffer becomes empty or the output buffer becomes full.  It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
+
+  The detailed semantics are as follows.  inflate performs one or both of the
+  following actions:
+
+  - Decompress more input starting at next_in and update next_in and avail_in
+    accordingly.  If not all input can be processed (because there is not
+    enough room in the output buffer), then next_in and avail_in are updated
+    accordingly, and processing will resume at this point for the next call of
+    inflate().
+
+  - Generate more output starting at next_out and update next_out and avail_out
+    accordingly.  inflate() provides as much output as possible, until there is
+    no more input data or no more space in the output buffer (see below about
+    the flush parameter).
+
+    Before the call of inflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming more
+  output, and updating the next_* and avail_* values accordingly.  If the
+  caller of inflate() does not provide both available input and available
+  output space, it is possible that there will be no progress made.  The
+  application can consume the uncompressed output when it wants, for example
+  when the output buffer is full (avail_out == 0), or after each call of
+  inflate().  If inflate returns Z_OK and with zero avail_out, it must be
+  called again after making room in the output buffer because there might be
+  more output pending.
+
+    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
+  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
+  output as possible to the output buffer.  Z_BLOCK requests that inflate()
+  stop if and when it gets to the next deflate block boundary.  When decoding
+  the zlib or gzip format, this will cause inflate() to return immediately
+  after the header and before the first block.  When doing a raw inflate,
+  inflate() will go ahead and process the first block, and will return when it
+  gets to the end of that block, or when it runs out of data.
+
+    The Z_BLOCK option assists in appending to or combining deflate streams.
+  To assist in this, on return inflate() always sets strm->data_type to the
+  number of unused bits in the last byte taken from strm->next_in, plus 64 if
+  inflate() is currently decoding the last block in the deflate stream, plus
+  128 if inflate() returned immediately after decoding an end-of-block code or
+  decoding the complete header up to just before the first byte of the deflate
+  stream.  The end-of-block will not be indicated until all of the uncompressed
+  data from that block has been written to strm->next_out.  The number of
+  unused bits may in general be greater than seven, except when bit 7 of
+  data_type is set, in which case the number of unused bits will be less than
+  eight.  data_type is set as noted here every time inflate() returns for all
+  flush options, and so can be used to determine the amount of currently
+  consumed input in bits.
+
+    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
+  end of each deflate block header is reached, before any actual data in that
+  block is decoded.  This allows the caller to determine the length of the
+  deflate block header for later use in random access within a deflate block.
+  256 is added to the value of strm->data_type when inflate() returns
+  immediately after reaching the end of the deflate block header.
+
+    inflate() should normally be called until it returns Z_STREAM_END or an
+  error.  However if all decompression is to be performed in a single step (a
+  single call of inflate), the parameter flush should be set to Z_FINISH.  In
+  this case all pending input is processed and all pending output is flushed;
+  avail_out must be large enough to hold all of the uncompressed data for the
+  operation to complete.  (The size of the uncompressed data may have been
+  saved by the compressor for this purpose.)  The use of Z_FINISH is not
+  required to perform an inflation in one step.  However it may be used to
+  inform inflate that a faster approach can be used for the single inflate()
+  call.  Z_FINISH also informs inflate to not maintain a sliding window if the
+  stream completes, which reduces inflate's memory footprint.  If the stream
+  does not complete, either because not all of the stream is provided or not
+  enough output space is provided, then a sliding window will be allocated and
+  inflate() can be called again to continue the operation as if Z_NO_FLUSH had
+  been used.
+
+     In this implementation, inflate() always flushes as much output as
+  possible to the output buffer, and always uses the faster approach on the
+  first call.  So the effects of the flush parameter in this implementation are
+  on the return value of inflate() as noted below, when inflate() returns early
+  when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
+  memory for a sliding window when Z_FINISH is used.
+
+     If a preset dictionary is needed after this call (see inflateSetDictionary
+  below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
+  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+  strm->adler to the Adler-32 checksum of all output produced so far (that is,
+  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
+  below.  At the end of the stream, inflate() checks that its computed Adler-32
+  checksum is equal to that saved by the compressor and returns Z_STREAM_END
+  only if the checksum is correct.
+
+    inflate() can decompress and check either zlib-wrapped or gzip-wrapped
+  deflate data.  The header type is detected automatically, if requested when
+  initializing with inflateInit2().  Any information contained in the gzip
+  header is not retained unless inflateGetHeader() is used.  When processing
+  gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
+  produced so far.  The CRC-32 is checked against the gzip trailer, as is the
+  uncompressed length, modulo 2^32.
+
+    inflate() returns Z_OK if some progress has been made (more input processed
+  or more output produced), Z_STREAM_END if the end of the compressed data has
+  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
+  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
+  corrupted (input stream not conforming to the zlib format or incorrect check
+  value, in which case strm->msg points to a string with a more specific
+  error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+  next_in or next_out was Z_NULL, or the state was inadvertently written over
+  by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
+  if no progress was possible or if there was not enough room in the output
+  buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
+  inflate() can be called again with more input and more output space to
+  continue decompressing.  If Z_DATA_ERROR is returned, the application may
+  then call inflateSync() to look for a good compression block if a partial
+  recovery of the data is to be attempted.
+*/
+
+
+ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any pending
+   output.
+
+     inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
+   was inconsistent.
+*/
+
+
+                        /* Advanced functions */
+
+/*
+    The following functions are needed only in some special applications.
+*/
+
+/*
+ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
+                                     int  level,
+                                     int  method,
+                                     int  windowBits,
+                                     int  memLevel,
+                                     int  strategy));
+
+     This is another version of deflateInit with more compression options.  The
+   fields next_in, zalloc, zfree and opaque must be initialized before by the
+   caller.
+
+     The method parameter is the compression method.  It must be Z_DEFLATED in
+   this version of the library.
+
+     The windowBits parameter is the base two logarithm of the window size
+   (the size of the history buffer).  It should be in the range 8..15 for this
+   version of the library.  Larger values of this parameter result in better
+   compression at the expense of memory usage.  The default value is 15 if
+   deflateInit is used instead.
+
+     For the current implementation of deflate(), a windowBits value of 8 (a
+   window size of 256 bytes) is not supported.  As a result, a request for 8
+   will result in 9 (a 512-byte window).  In that case, providing 8 to
+   inflateInit2() will result in an error when the zlib header with 9 is
+   checked against the initialization of inflate().  The remedy is to not use 8
+   with deflateInit2() with this initialization, or at least in that case use 9
+   with inflateInit2().
+
+     windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
+   determines the window size.  deflate() will then generate raw deflate data
+   with no zlib header or trailer, and will not compute a check value.
+
+     windowBits can also be greater than 15 for optional gzip encoding.  Add
+   16 to windowBits to write a simple gzip header and trailer around the
+   compressed data instead of a zlib wrapper.  The gzip header will have no
+   file name, no extra data, no comment, no modification time (set to zero), no
+   header crc, and the operating system will be set to the appropriate value,
+   if the operating system was determined at compile time.  If a gzip stream is
+   being written, strm->adler is a CRC-32 instead of an Adler-32.
+
+     For raw deflate or gzip encoding, a request for a 256-byte window is
+   rejected as invalid, since only the zlib header provides a means of
+   transmitting the window size to the decompressor.
+
+     The memLevel parameter specifies how much memory should be allocated
+   for the internal compression state.  memLevel=1 uses minimum memory but is
+   slow and reduces compression ratio; memLevel=9 uses maximum memory for
+   optimal speed.  The default value is 8.  See zconf.h for total memory usage
+   as a function of windowBits and memLevel.
+
+     The strategy parameter is used to tune the compression algorithm.  Use the
+   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
+   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
+   string match), or Z_RLE to limit match distances to one (run-length
+   encoding).  Filtered data consists mostly of small values with a somewhat
+   random distribution.  In this case, the compression algorithm is tuned to
+   compress them better.  The effect of Z_FILTERED is to force more Huffman
+   coding and less string matching; it is somewhat intermediate between
+   Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
+   fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
+   strategy parameter only affects the compression ratio but not the
+   correctness of the compressed output even if it is not set appropriately.
+   Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
+   decoder for special applications.
+
+     deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
+   method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
+   incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
+   set to null if there is no error message.  deflateInit2 does not perform any
+   compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
+                                             const Bytef *dictionary,
+                                             uInt  dictLength));
+/*
+     Initializes the compression dictionary from the given byte sequence
+   without producing any compressed output.  When using the zlib format, this
+   function must be called immediately after deflateInit, deflateInit2 or
+   deflateReset, and before any call of deflate.  When doing raw deflate, this
+   function must be called either before any call of deflate, or immediately
+   after the completion of a deflate block, i.e. after all input has been
+   consumed and all output has been delivered when using any of the flush
+   options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
+   compressor and decompressor must use exactly the same dictionary (see
+   inflateSetDictionary).
+
+     The dictionary should consist of strings (byte sequences) that are likely
+   to be encountered later in the data to be compressed, with the most commonly
+   used strings preferably put towards the end of the dictionary.  Using a
+   dictionary is most useful when the data to be compressed is short and can be
+   predicted with good accuracy; the data can then be compressed better than
+   with the default empty dictionary.
+
+     Depending on the size of the compression data structures selected by
+   deflateInit or deflateInit2, a part of the dictionary may in effect be
+   discarded, for example if the dictionary is larger than the window size
+   provided in deflateInit or deflateInit2.  Thus the strings most likely to be
+   useful should be put at the end of the dictionary, not at the front.  In
+   addition, the current implementation of deflate will use at most the window
+   size minus 262 bytes of the provided dictionary.
+
+     Upon return of this function, strm->adler is set to the Adler-32 value
+   of the dictionary; the decompressor may later use this value to determine
+   which dictionary has been used by the compressor.  (The Adler-32 value
+   applies to the whole dictionary even if only a subset of the dictionary is
+   actually used by the compressor.) If a raw deflate was requested, then the
+   Adler-32 value is not computed and strm->adler is not set.
+
+     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
+   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
+   inconsistent (for example if deflate has already been called for this stream
+   or if not at a block boundary for raw deflate).  deflateSetDictionary does
+   not perform any compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by deflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If deflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     deflateGetDictionary() may return a length less than the window size, even
+   when more than the window size in input has been provided. It may return up
+   to 258 bytes less in that case, due to how zlib's implementation of deflate
+   manages the sliding window and lookahead for matches, where matches can be
+   up to 258 bytes long. If the application needs the last window-size bytes of
+   input, then that would need to be saved by the application outside of zlib.
+
+     deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
+                                    z_streamp source));
+/*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when several compression strategies will be
+   tried, for example when there are several ways of pre-processing the input
+   data with a filter.  The streams that will be discarded should then be freed
+   by calling deflateEnd.  Note that deflateCopy duplicates the internal
+   compression state which can be quite large, so this strategy is slow and can
+   consume lots of memory.
+
+     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
+   destination.
+*/
+
+ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
+/*
+     This function is equivalent to deflateEnd followed by deflateInit, but
+   does not free and reallocate the internal compression state.  The stream
+   will leave the compression level and any other attributes that may have been
+   set unchanged.
+
+     deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
+                                      int level,
+                                      int strategy));
+/*
+     Dynamically update the compression level and compression strategy.  The
+   interpretation of level and strategy is as in deflateInit2().  This can be
+   used to switch between compression and straight copy of the input data, or
+   to switch to a different kind of input data requiring a different strategy.
+   If the compression approach (which is a function of the level) or the
+   strategy is changed, and if any input has been consumed in a previous
+   deflate() call, then the input available so far is compressed with the old
+   level and strategy using deflate(strm, Z_BLOCK).  There are three approaches
+   for the compression levels 0, 1..3, and 4..9 respectively.  The new level
+   and strategy will take effect at the next call of deflate().
+
+     If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
+   not have enough output space to complete, then the parameter change will not
+   take effect.  In this case, deflateParams() can be called again with the
+   same parameters and more output space to try again.
+
+     In order to assure a change in the parameters on the first try, the
+   deflate stream should be flushed using deflate() with Z_BLOCK or other flush
+   request until strm.avail_out is not zero, before calling deflateParams().
+   Then no more input data should be provided before the deflateParams() call.
+   If this is done, the old level and strategy will be applied to the data
+   compressed before deflateParams(), and the new level and strategy will be
+   applied to the the data compressed after deflateParams().
+
+     deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
+   state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
+   there was not enough output space to complete the compression of the
+   available input data before a change in the strategy or approach.  Note that
+   in the case of a Z_BUF_ERROR, the parameters are not changed.  A return
+   value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
+   retried with more output space.
+*/
+
+ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
+                                    int good_length,
+                                    int max_lazy,
+                                    int nice_length,
+                                    int max_chain));
+/*
+     Fine tune deflate's internal compression parameters.  This should only be
+   used by someone who understands the algorithm used by zlib's deflate for
+   searching for the best matching string, and even then only by the most
+   fanatic optimizer trying to squeeze out the last compressed bit for their
+   specific input data.  Read the deflate.c source code for the meaning of the
+   max_lazy, good_length, nice_length, and max_chain parameters.
+
+     deflateTune() can be called after deflateInit() or deflateInit2(), and
+   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
+ */
+
+ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
+                                       uLong sourceLen));
+/*
+     deflateBound() returns an upper bound on the compressed size after
+   deflation of sourceLen bytes.  It must be called after deflateInit() or
+   deflateInit2(), and after deflateSetHeader(), if used.  This would be used
+   to allocate an output buffer for deflation in a single pass, and so would be
+   called before deflate().  If that first deflate() call is provided the
+   sourceLen input bytes, an output buffer allocated to the size returned by
+   deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
+   to return Z_STREAM_END.  Note that it is possible for the compressed size to
+   be larger than the value returned by deflateBound() if flush options other
+   than Z_FINISH or Z_NO_FLUSH are used.
+*/
+
+ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
+                                       unsigned *pending,
+                                       int *bits));
+/*
+     deflatePending() returns the number of bytes and bits of output that have
+   been generated, but not yet provided in the available output.  The bytes not
+   provided would be due to the available output space having being consumed.
+   The number of bits of output not provided are between 0 and 7, where they
+   await more bits to join them in order to fill out a full byte.  If pending
+   or bits are Z_NULL, then those values are not set.
+
+     deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+ */
+
+ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
+                                     int bits,
+                                     int value));
+/*
+     deflatePrime() inserts bits in the deflate output stream.  The intent
+   is that this function is used to start off the deflate output with the bits
+   leftover from a previous deflate stream when appending to it.  As such, this
+   function can only be used for raw deflate, and must be used before the first
+   deflate() call after a deflateInit2() or deflateReset().  bits must be less
+   than or equal to 16, and that many of the least significant bits of value
+   will be inserted in the output.
+
+     deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
+   room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
+   source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
+                                         gz_headerp head));
+/*
+     deflateSetHeader() provides gzip header information for when a gzip
+   stream is requested by deflateInit2().  deflateSetHeader() may be called
+   after deflateInit2() or deflateReset() and before the first call of
+   deflate().  The text, time, os, extra field, name, and comment information
+   in the provided gz_header structure are written to the gzip header (xflag is
+   ignored -- the extra flags are set according to the compression level).  The
+   caller must assure that, if not Z_NULL, name and comment are terminated with
+   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
+   available there.  If hcrc is true, a gzip header crc is included.  Note that
+   the current versions of the command-line version of gzip (up through version
+   1.3.x) do not support header crc's, and will report that it is a "multi-part
+   gzip file" and give up.
+
+     If deflateSetHeader is not used, the default gzip header has text false,
+   the time set to zero, and os set to 255, with no extra, name, or comment
+   fields.  The gzip header is returned to the default state by deflateReset().
+
+     deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
+                                     int  windowBits));
+
+     This is another version of inflateInit with an extra parameter.  The
+   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
+   before by the caller.
+
+     The windowBits parameter is the base two logarithm of the maximum window
+   size (the size of the history buffer).  It should be in the range 8..15 for
+   this version of the library.  The default value is 15 if inflateInit is used
+   instead.  windowBits must be greater than or equal to the windowBits value
+   provided to deflateInit2() while compressing, or it must be equal to 15 if
+   deflateInit2() was not used.  If a compressed stream with a larger window
+   size is given as input, inflate() will return with the error code
+   Z_DATA_ERROR instead of trying to allocate a larger window.
+
+     windowBits can also be zero to request that inflate use the window size in
+   the zlib header of the compressed stream.
+
+     windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
+   determines the window size.  inflate() will then process raw deflate data,
+   not looking for a zlib or gzip header, not generating a check value, and not
+   looking for any check values for comparison at the end of the stream.  This
+   is for use with other formats that use the deflate compressed data format
+   such as zip.  Those formats provide their own check values.  If a custom
+   format is developed using the raw deflate format for compressed data, it is
+   recommended that a check value such as an Adler-32 or a CRC-32 be applied to
+   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
+   most applications, the zlib format should be used as is.  Note that comments
+   above on the use in deflateInit2() applies to the magnitude of windowBits.
+
+     windowBits can also be greater than 15 for optional gzip decoding.  Add
+   32 to windowBits to enable zlib and gzip decoding with automatic header
+   detection, or add 16 to decode only the gzip format (the zlib format will
+   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
+   CRC-32 instead of an Adler-32.  Unlike the gunzip utility and gzread() (see
+   below), inflate() will not automatically decode concatenated gzip streams.
+   inflate() will return Z_STREAM_END at the end of the gzip stream.  The state
+   would need to be reset to continue decoding a subsequent gzip stream.
+
+     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
+   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
+   invalid, such as a null pointer to the structure.  msg is set to null if
+   there is no error message.  inflateInit2 does not perform any decompression
+   apart from possibly reading the zlib header if present: actual decompression
+   will be done by inflate().  (So next_in and avail_in may be modified, but
+   next_out and avail_out are unused and unchanged.) The current implementation
+   of inflateInit2() does not process any header information -- that is
+   deferred until inflate() is called.
+*/
+
+ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
+                                             const Bytef *dictionary,
+                                             uInt  dictLength));
+/*
+     Initializes the decompression dictionary from the given uncompressed byte
+   sequence.  This function must be called immediately after a call of inflate,
+   if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
+   can be determined from the Adler-32 value returned by that call of inflate.
+   The compressor and decompressor must use exactly the same dictionary (see
+   deflateSetDictionary).  For raw inflate, this function can be called at any
+   time to set the dictionary.  If the provided dictionary is smaller than the
+   window and there is already data in the window, then the provided dictionary
+   will amend what's there.  The application must insure that the dictionary
+   that was used for compression is provided.
+
+     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
+   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
+   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
+   expected one (incorrect Adler-32 value).  inflateSetDictionary does not
+   perform any decompression: this will be done by subsequent calls of
+   inflate().
+*/
+
+ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by inflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If inflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
+/*
+     Skips invalid compressed data until a possible full flush point (see above
+   for the description of deflate with Z_FULL_FLUSH) can be found, or until all
+   available input is skipped.  No output is provided.
+
+     inflateSync searches for a 00 00 FF FF pattern in the compressed data.
+   All full flush points have this pattern, but not all occurrences of this
+   pattern are full flush points.
+
+     inflateSync returns Z_OK if a possible full flush point has been found,
+   Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
+   has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
+   In the success case, the application may save the current current value of
+   total_in which indicates where valid compressed data was found.  In the
+   error case, the application may repeatedly call inflateSync, providing more
+   input each time, until success or end of the input data.
+*/
+
+ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
+                                    z_streamp source));
+/*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when randomly accessing a large stream.  The
+   first pass through the stream can periodically record the inflate state,
+   allowing restarting inflate at those points when randomly accessing the
+   stream.
+
+     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
+   destination.
+*/
+
+ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
+/*
+     This function is equivalent to inflateEnd followed by inflateInit,
+   but does not free and reallocate the internal decompression state.  The
+   stream will keep attributes that may have been set by inflateInit2.
+
+     inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
+                                      int windowBits));
+/*
+     This function is the same as inflateReset, but it also permits changing
+   the wrap and window size requests.  The windowBits parameter is interpreted
+   the same as it is for inflateInit2.  If the window size is changed, then the
+   memory allocated for the window is freed, and the window will be reallocated
+   by inflate() if needed.
+
+     inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL), or if
+   the windowBits parameter is invalid.
+*/
+
+ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
+                                     int bits,
+                                     int value));
+/*
+     This function inserts bits in the inflate input stream.  The intent is
+   that this function is used to start inflating at a bit position in the
+   middle of a byte.  The provided bits will be used before any bytes are used
+   from next_in.  This function should only be used with raw inflate, and
+   should be used before the first inflate() call after inflateInit2() or
+   inflateReset().  bits must be less than or equal to 16, and that many of the
+   least significant bits of value will be inserted in the input.
+
+     If bits is negative, then the input stream bit buffer is emptied.  Then
+   inflatePrime() can be called again to put bits in the buffer.  This is used
+   to clear out bits leftover after feeding inflate a block description prior
+   to feeding inflate codes.
+
+     inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
+/*
+     This function returns two values, one in the lower 16 bits of the return
+   value, and the other in the remaining upper bits, obtained by shifting the
+   return value down 16 bits.  If the upper value is -1 and the lower value is
+   zero, then inflate() is currently decoding information outside of a block.
+   If the upper value is -1 and the lower value is non-zero, then inflate is in
+   the middle of a stored block, with the lower value equaling the number of
+   bytes from the input remaining to copy.  If the upper value is not -1, then
+   it is the number of bits back from the current bit position in the input of
+   the code (literal or length/distance pair) currently being processed.  In
+   that case the lower value is the number of bytes already emitted for that
+   code.
+
+     A code is being processed if inflate is waiting for more input to complete
+   decoding of the code, or if it has completed decoding but is waiting for
+   more output space to write the literal or match data.
+
+     inflateMark() is used to mark locations in the input data for random
+   access, which may be at bit positions, and to note those cases where the
+   output of a code may span boundaries of random access blocks.  The current
+   location in the input stream can be determined from avail_in and data_type
+   as noted in the description for the Z_BLOCK flush parameter for inflate.
+
+     inflateMark returns the value noted above, or -65536 if the provided
+   source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
+                                         gz_headerp head));
+/*
+     inflateGetHeader() requests that gzip header information be stored in the
+   provided gz_header structure.  inflateGetHeader() may be called after
+   inflateInit2() or inflateReset(), and before the first call of inflate().
+   As inflate() processes the gzip stream, head->done is zero until the header
+   is completed, at which time head->done is set to one.  If a zlib stream is
+   being decoded, then head->done is set to -1 to indicate that there will be
+   no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
+   used to force inflate() to return immediately after header processing is
+   complete and before any actual data is decompressed.
+
+     The text, time, xflags, and os fields are filled in with the gzip header
+   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
+   was valid if done is set to one.) If extra is not Z_NULL, then extra_max
+   contains the maximum number of bytes to write to extra.  Once done is true,
+   extra_len contains the actual extra field length, and extra contains the
+   extra field, or that field truncated if extra_max is less than extra_len.
+   If name is not Z_NULL, then up to name_max characters are written there,
+   terminated with a zero unless the length is greater than name_max.  If
+   comment is not Z_NULL, then up to comm_max characters are written there,
+   terminated with a zero unless the length is greater than comm_max.  When any
+   of extra, name, or comment are not Z_NULL and the respective field is not
+   present in the header, then that field is set to Z_NULL to signal its
+   absence.  This allows the use of deflateSetHeader() with the returned
+   structure to duplicate the header.  However if those fields are set to
+   allocated memory, then the application will need to save those pointers
+   elsewhere so that they can be eventually freed.
+
+     If inflateGetHeader is not used, then the header information is simply
+   discarded.  The header is always checked for validity, including the header
+   CRC if present.  inflateReset() will reset the process to discard the header
+   information.  The application would need to call inflateGetHeader() again to
+   retrieve the header from the next gzip stream.
+
+     inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
+                                        unsigned char FAR *window));
+
+     Initialize the internal stream state for decompression using inflateBack()
+   calls.  The fields zalloc, zfree and opaque in strm must be initialized
+   before the call.  If zalloc and zfree are Z_NULL, then the default library-
+   derived memory allocation routines are used.  windowBits is the base two
+   logarithm of the window size, in the range 8..15.  window is a caller
+   supplied buffer of that size.  Except for special applications where it is
+   assured that deflate was used with small window sizes, windowBits must be 15
+   and a 32K byte window must be supplied to be able to decompress general
+   deflate streams.
+
+     See inflateBack() for the usage of these routines.
+
+     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
+   the parameters are invalid, Z_MEM_ERROR if the internal state could not be
+   allocated, or Z_VERSION_ERROR if the version of the library does not match
+   the version of the header file.
+*/
+
+typedef unsigned (*in_func) OF((void FAR *,
+                                z_const unsigned char FAR * FAR *));
+typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
+
+ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
+                                    in_func in, void FAR *in_desc,
+                                    out_func out, void FAR *out_desc));
+/*
+     inflateBack() does a raw inflate with a single call using a call-back
+   interface for input and output.  This is potentially more efficient than
+   inflate() for file i/o applications, in that it avoids copying between the
+   output and the sliding window by simply making the window itself the output
+   buffer.  inflate() can be faster on modern CPUs when used with large
+   buffers.  inflateBack() trusts the application to not change the output
+   buffer passed by the output function, at least until inflateBack() returns.
+
+     inflateBackInit() must be called first to allocate the internal state
+   and to initialize the state with the user-provided window buffer.
+   inflateBack() may then be used multiple times to inflate a complete, raw
+   deflate stream with each call.  inflateBackEnd() is then called to free the
+   allocated state.
+
+     A raw deflate stream is one with no zlib or gzip header or trailer.
+   This routine would normally be used in a utility that reads zip or gzip
+   files and writes out uncompressed files.  The utility would decode the
+   header and process the trailer on its own, hence this routine expects only
+   the raw deflate stream to decompress.  This is different from the default
+   behavior of inflate(), which expects a zlib header and trailer around the
+   deflate stream.
+
+     inflateBack() uses two subroutines supplied by the caller that are then
+   called by inflateBack() for input and output.  inflateBack() calls those
+   routines until it reads a complete deflate stream and writes out all of the
+   uncompressed data, or until it encounters an error.  The function's
+   parameters and return types are defined above in the in_func and out_func
+   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
+   number of bytes of provided input, and a pointer to that input in buf.  If
+   there is no input available, in() must return zero -- buf is ignored in that
+   case -- and inflateBack() will return a buffer error.  inflateBack() will
+   call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
+   out() should return zero on success, or non-zero on failure.  If out()
+   returns non-zero, inflateBack() will return with an error.  Neither in() nor
+   out() are permitted to change the contents of the window provided to
+   inflateBackInit(), which is also the buffer that out() uses to write from.
+   The length written by out() will be at most the window size.  Any non-zero
+   amount of input may be provided by in().
+
+     For convenience, inflateBack() can be provided input on the first call by
+   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
+   in() will be called.  Therefore strm->next_in must be initialized before
+   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
+   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
+   must also be initialized, and then if strm->avail_in is not zero, input will
+   initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
+
+     The in_desc and out_desc parameters of inflateBack() is passed as the
+   first parameter of in() and out() respectively when they are called.  These
+   descriptors can be optionally used to pass any information that the caller-
+   supplied in() and out() functions need to do their job.
+
+     On return, inflateBack() will set strm->next_in and strm->avail_in to
+   pass back any unused input that was provided by the last in() call.  The
+   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
+   if in() or out() returned an error, Z_DATA_ERROR if there was a format error
+   in the deflate stream (in which case strm->msg is set to indicate the nature
+   of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
+   In the case of Z_BUF_ERROR, an input or output error can be distinguished
+   using strm->next_in which will be Z_NULL only if in() returned an error.  If
+   strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
+   non-zero.  (in() will always be called before out(), so strm->next_in is
+   assured to be defined if out() returns non-zero.)  Note that inflateBack()
+   cannot return Z_OK.
+*/
+
+ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
+/*
+     All memory allocated by inflateBackInit() is freed.
+
+     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
+   state was inconsistent.
+*/
+
+ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
+/* Return flags indicating compile-time options.
+
+    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
+     1.0: size of uInt
+     3.2: size of uLong
+     5.4: size of voidpf (pointer)
+     7.6: size of z_off_t
+
+    Compiler, assembler, and debug options:
+     8: ZLIB_DEBUG
+     9: ASMV or ASMINF -- use ASM code
+     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
+     11: 0 (reserved)
+
+    One-time table building (smaller code, but not thread-safe if true):
+     12: BUILDFIXED -- build static block decoding tables when needed
+     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
+     14,15: 0 (reserved)
+
+    Library content (indicates missing functionality):
+     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
+                          deflate code when not needed)
+     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
+                    and decode gzip streams (to avoid linking crc code)
+     18-19: 0 (reserved)
+
+    Operation variations (changes in library functionality):
+     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
+     21: FASTEST -- deflate algorithm with only one, lowest compression level
+     22,23: 0 (reserved)
+
+    The sprintf variant used by gzprintf (zero is best):
+     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
+     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
+     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
+
+    Remainder:
+     27-31: 0 (reserved)
+ */
+
+#ifndef Z_SOLO
+
+                        /* utility functions */
+
+/*
+     The following utility functions are implemented on top of the basic
+   stream-oriented functions.  To simplify the interface, some default options
+   are assumed (compression level and memory usage, standard memory allocation
+   functions).  The source code of these utility functions can be modified if
+   you need special options.
+*/
+
+ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
+                                 const Bytef *source, uLong sourceLen));
+/*
+     Compresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be at least the value returned by
+   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
+   compressed data.  compress() is equivalent to compress2() with a level
+   parameter of Z_DEFAULT_COMPRESSION.
+
+     compress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer.
+*/
+
+ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
+                                  const Bytef *source, uLong sourceLen,
+                                  int level));
+/*
+     Compresses the source buffer into the destination buffer.  The level
+   parameter has the same meaning as in deflateInit.  sourceLen is the byte
+   length of the source buffer.  Upon entry, destLen is the total size of the
+   destination buffer, which must be at least the value returned by
+   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
+   compressed data.
+
+     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+   Z_STREAM_ERROR if the level parameter is invalid.
+*/
+
+ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
+/*
+     compressBound() returns an upper bound on the compressed size after
+   compress() or compress2() on sourceLen bytes.  It would be used before a
+   compress() or compress2() call to allocate the destination buffer.
+*/
+
+ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
+                                   const Bytef *source, uLong sourceLen));
+/*
+     Decompresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data.  (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit, destLen
+   is the actual size of the uncompressed data.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
+   the case where there is not enough room, uncompress() will fill the output
+   buffer with the uncompressed data up to that point.
+*/
+
+ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest,   uLongf *destLen,
+                                    const Bytef *source, uLong *sourceLen));
+/*
+     Same as uncompress, except that sourceLen is a pointer, where the
+   length of the source is *sourceLen.  On return, *sourceLen is the number of
+   source bytes consumed.
+*/
+
+                        /* gzip file access functions */
+
+/*
+     This library supports reading and writing files in gzip (.gz) format with
+   an interface similar to that of stdio, using the functions that start with
+   "gz".  The gzip format is different from the zlib format.  gzip is a gzip
+   wrapper, documented in RFC 1952, wrapped around a deflate stream.
+*/
+
+typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */
+
+/*
+ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
+
+     Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
+   in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
+   a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
+   compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
+   for fixed code compression as in "wb9F".  (See the description of
+   deflateInit2 for more information about the strategy parameter.)  'T' will
+   request transparent writing or appending with no compression and not using
+   the gzip format.
+
+     "a" can be used instead of "w" to request that the gzip stream that will
+   be written be appended to the file.  "+" will result in an error, since
+   reading and writing to the same gzip file is not supported.  The addition of
+   "x" when writing will create the file exclusively, which fails if the file
+   already exists.  On systems that support it, the addition of "e" when
+   reading or writing will set the flag to close the file on an execve() call.
+
+     These functions, as well as gzip, will read and decode a sequence of gzip
+   streams in a file.  The append function of gzopen() can be used to create
+   such a file.  (Also see gzflush() for another way to do this.)  When
+   appending, gzopen does not test whether the file begins with a gzip stream,
+   nor does it look for the end of the gzip streams to begin appending.  gzopen
+   will simply append a gzip stream to the existing file.
+
+     gzopen can be used to read a file which is not in gzip format; in this
+   case gzread will directly read from the file without decompression.  When
+   reading, this will be detected automatically by looking for the magic two-
+   byte gzip header.
+
+     gzopen returns NULL if the file could not be opened, if there was
+   insufficient memory to allocate the gzFile state, or if an invalid mode was
+   specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
+   errno can be checked to determine if the reason gzopen failed was that the
+   file could not be opened.
+*/
+
+ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
+/*
+     gzdopen associates a gzFile with the file descriptor fd.  File descriptors
+   are obtained from calls like open, dup, creat, pipe or fileno (if the file
+   has been previously opened with fopen).  The mode parameter is as in gzopen.
+
+     The next call of gzclose on the returned gzFile will also close the file
+   descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
+   fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
+   mode);.  The duplicated descriptor should be saved to avoid a leak, since
+   gzdopen does not close fd if it fails.  If you are using fileno() to get the
+   file descriptor from a FILE *, then you will have to use dup() to avoid
+   double-close()ing the file descriptor.  Both gzclose() and fclose() will
+   close the associated file descriptor, so they need to have different file
+   descriptors.
+
+     gzdopen returns NULL if there was insufficient memory to allocate the
+   gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
+   provided, or '+' was provided), or if fd is -1.  The file descriptor is not
+   used until the next gz* read, write, seek, or close operation, so gzdopen
+   will not detect if fd is invalid (unless fd is -1).
+*/
+
+ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
+/*
+     Set the internal buffer size used by this library's functions.  The
+   default buffer size is 8192 bytes.  This function must be called after
+   gzopen() or gzdopen(), and before any other calls that read or write the
+   file.  The buffer memory allocation is always deferred to the first read or
+   write.  Three times that size in buffer space is allocated.  A larger buffer
+   size of, for example, 64K or 128K bytes will noticeably increase the speed
+   of decompression (reading).
+
+     The new buffer size also affects the maximum length for gzprintf().
+
+     gzbuffer() returns 0 on success, or -1 on failure, such as being called
+   too late.
+*/
+
+ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
+/*
+     Dynamically update the compression level or strategy.  See the description
+   of deflateInit2 for the meaning of these parameters.  Previously provided
+   data is flushed before the parameter change.
+
+     gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
+   opened for writing, Z_ERRNO if there is an error writing the flushed data,
+   or Z_MEM_ERROR if there is a memory allocation error.
+*/
+
+ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
+/*
+     Reads the given number of uncompressed bytes from the compressed file.  If
+   the input file is not in gzip format, gzread copies the given number of
+   bytes into the buffer directly from the file.
+
+     After reaching the end of a gzip stream in the input, gzread will continue
+   to read, looking for another gzip stream.  Any number of gzip streams may be
+   concatenated in the input file, and will all be decompressed by gzread().
+   If something other than a gzip stream is encountered after a gzip stream,
+   that remaining trailing garbage is ignored (and no error is returned).
+
+     gzread can be used to read a gzip file that is being concurrently written.
+   Upon reaching the end of the input, gzread will return with the available
+   data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
+   gzclearerr can be used to clear the end of file indicator in order to permit
+   gzread to be tried again.  Z_OK indicates that a gzip stream was completed
+   on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
+   middle of a gzip stream.  Note that gzread does not return -1 in the event
+   of an incomplete gzip stream.  This error is deferred until gzclose(), which
+   will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
+   stream.  Alternatively, gzerror can be used before gzclose to detect this
+   case.
+
+     gzread returns the number of uncompressed bytes actually read, less than
+   len for end of file, or -1 for error.  If len is too large to fit in an int,
+   then nothing is read, -1 is returned, and the error state is set to
+   Z_STREAM_ERROR.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
+                                     gzFile file));
+/*
+     Read up to nitems items of size size from file to buf, otherwise operating
+   as gzread() does.  This duplicates the interface of stdio's fread(), with
+   size_t request and return types.  If the library defines size_t, then
+   z_size_t is identical to size_t.  If not, then z_size_t is an unsigned
+   integer type that can contain a pointer.
+
+     gzfread() returns the number of full items read of size size, or zero if
+   the end of the file was reached and a full item could not be read, or if
+   there was an error.  gzerror() must be consulted if zero is returned in
+   order to determine if there was an error.  If the multiplication of size and
+   nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
+   is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+     In the event that the end of file is reached and only a partial item is
+   available at the end, i.e. the remaining uncompressed data length is not a
+   multiple of size, then the final partial item is nevetheless read into buf
+   and the end-of-file flag is set.  The length of the partial item read is not
+   provided, but could be inferred from the result of gztell().  This behavior
+   is the same as the behavior of fread() implementations in common libraries,
+   but it prevents the direct use of gzfread() to read a concurrently written
+   file, reseting and retrying on end-of-file, when size is not 1.
+*/
+
+ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
+                                voidpc buf, unsigned len));
+/*
+     Writes the given number of uncompressed bytes into the compressed file.
+   gzwrite returns the number of uncompressed bytes written or 0 in case of
+   error.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
+                                      z_size_t nitems, gzFile file));
+/*
+     gzfwrite() writes nitems items of size size from buf to file, duplicating
+   the interface of stdio's fwrite(), with size_t request and return types.  If
+   the library defines size_t, then z_size_t is identical to size_t.  If not,
+   then z_size_t is an unsigned integer type that can contain a pointer.
+
+     gzfwrite() returns the number of full items written of size size, or zero
+   if there was an error.  If the multiplication of size and nitems overflows,
+   i.e. the product does not fit in a z_size_t, then nothing is written, zero
+   is returned, and the error state is set to Z_STREAM_ERROR.
+*/
+
+ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
+/*
+     Converts, formats, and writes the arguments to the compressed file under
+   control of the format string, as in fprintf.  gzprintf returns the number of
+   uncompressed bytes actually written, or a negative zlib error code in case
+   of error.  The number of uncompressed bytes written is limited to 8191, or
+   one less than the buffer size given to gzbuffer().  The caller should assure
+   that this limit is not exceeded.  If it is exceeded, then gzprintf() will
+   return an error (0) with nothing written.  In this case, there may also be a
+   buffer overflow with unpredictable consequences, which is possible only if
+   zlib was compiled with the insecure functions sprintf() or vsprintf()
+   because the secure snprintf() or vsnprintf() functions were not available.
+   This can be determined using zlibCompileFlags().
+*/
+
+ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
+/*
+     Writes the given null-terminated string to the compressed file, excluding
+   the terminating null character.
+
+     gzputs returns the number of characters written, or -1 in case of error.
+*/
+
+ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
+/*
+     Reads bytes from the compressed file until len-1 characters are read, or a
+   newline character is read and transferred to buf, or an end-of-file
+   condition is encountered.  If any characters are read or if len == 1, the
+   string is terminated with a null character.  If no characters are read due
+   to an end-of-file or len < 1, then the buffer is left untouched.
+
+     gzgets returns buf which is a null-terminated string, or it returns NULL
+   for end-of-file or in case of error.  If there was an error, the contents at
+   buf are indeterminate.
+*/
+
+ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
+/*
+     Writes c, converted to an unsigned char, into the compressed file.  gzputc
+   returns the value that was written, or -1 in case of error.
+*/
+
+ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
+/*
+     Reads one byte from the compressed file.  gzgetc returns this byte or -1
+   in case of end of file or error.  This is implemented as a macro for speed.
+   As such, it does not do all of the checking the other functions do.  I.e.
+   it does not check to see if file is NULL, nor whether the structure file
+   points to has been clobbered or not.
+*/
+
+ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
+/*
+     Push one character back onto the stream to be read as the first character
+   on the next read.  At least one character of push-back is allowed.
+   gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
+   fail if c is -1, and may fail if a character has been pushed but not read
+   yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
+   output buffer size of pushed characters is allowed.  (See gzbuffer above.)
+   The pushed character will be discarded if the stream is repositioned with
+   gzseek() or gzrewind().
+*/
+
+ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
+/*
+     Flushes all pending output into the compressed file.  The parameter flush
+   is as in the deflate() function.  The return value is the zlib error number
+   (see function gzerror below).  gzflush is only permitted when writing.
+
+     If the flush parameter is Z_FINISH, the remaining data is written and the
+   gzip stream is completed in the output.  If gzwrite() is called again, a new
+   gzip stream will be started in the output.  gzread() is able to read such
+   concatenated gzip streams.
+
+     gzflush should be called only when strictly necessary because it will
+   degrade compression if called too often.
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
+                                   z_off_t offset, int whence));
+
+     Sets the starting position for the next gzread or gzwrite on the given
+   compressed file.  The offset represents a number of bytes in the
+   uncompressed data stream.  The whence parameter is defined as in lseek(2);
+   the value SEEK_END is not supported.
+
+     If the file is opened for reading, this function is emulated but can be
+   extremely slow.  If the file is opened for writing, only forward seeks are
+   supported; gzseek then compresses a sequence of zeroes up to the new
+   starting position.
+
+     gzseek returns the resulting offset location as measured in bytes from
+   the beginning of the uncompressed stream, or -1 in case of error, in
+   particular if the file is opened for writing and the new starting position
+   would be before the current position.
+*/
+
+ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
+/*
+     Rewinds the given file. This function is supported only for reading.
+
+     gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
+
+     Returns the starting position for the next gzread or gzwrite on the given
+   compressed file.  This position represents a number of bytes in the
+   uncompressed data stream, and is zero when starting, even if appending or
+   reading a gzip stream from the middle of a file using gzdopen().
+
+     gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
+
+     Returns the current offset in the file being read or written.  This offset
+   includes the count of bytes that precede the gzip stream, for example when
+   appending or when using gzdopen() for reading.  When reading, the offset
+   does not include as yet unused buffered input.  This information can be used
+   for a progress indicator.  On error, gzoffset() returns -1.
+*/
+
+ZEXTERN int ZEXPORT gzeof OF((gzFile file));
+/*
+     Returns true (1) if the end-of-file indicator has been set while reading,
+   false (0) otherwise.  Note that the end-of-file indicator is set only if the
+   read tried to go past the end of the input, but came up short.  Therefore,
+   just like feof(), gzeof() may return false even if there is no more data to
+   read, in the event that the last read request was for the exact number of
+   bytes remaining in the input file.  This will happen if the input file size
+   is an exact multiple of the buffer size.
+
+     If gzeof() returns true, then the read functions will return no more data,
+   unless the end-of-file indicator is reset by gzclearerr() and the input file
+   has grown since the previous end of file was detected.
+*/
+
+ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
+/*
+     Returns true (1) if file is being copied directly while reading, or false
+   (0) if file is a gzip stream being decompressed.
+
+     If the input file is empty, gzdirect() will return true, since the input
+   does not contain a gzip stream.
+
+     If gzdirect() is used immediately after gzopen() or gzdopen() it will
+   cause buffers to be allocated to allow reading the file to determine if it
+   is a gzip file.  Therefore if gzbuffer() is used, it should be called before
+   gzdirect().
+
+     When writing, gzdirect() returns true (1) if transparent writing was
+   requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
+   gzdirect() is not needed when writing.  Transparent writing must be
+   explicitly requested, so the application already knows the answer.  When
+   linking statically, using gzdirect() will include all of the zlib code for
+   gzip file reading and decompression, which may not be desired.)
+*/
+
+ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
+/*
+     Flushes all pending output if necessary, closes the compressed file and
+   deallocates the (de)compression state.  Note that once file is closed, you
+   cannot call gzerror with file, since its structures have been deallocated.
+   gzclose must not be called more than once on the same file, just as free
+   must not be called more than once on the same allocation.
+
+     gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
+   file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
+   last read ended in the middle of a gzip stream, or Z_OK on success.
+*/
+
+ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
+ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
+/*
+     Same as gzclose(), but gzclose_r() is only for use when reading, and
+   gzclose_w() is only for use when writing or appending.  The advantage to
+   using these instead of gzclose() is that they avoid linking in zlib
+   compression or decompression code that is not used when only reading or only
+   writing respectively.  If gzclose() is used, then both compression and
+   decompression code will be included the application when linking to a static
+   zlib library.
+*/
+
+ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
+/*
+     Returns the error message for the last error which occurred on the given
+   compressed file.  errnum is set to zlib error number.  If an error occurred
+   in the file system and not in the compression library, errnum is set to
+   Z_ERRNO and the application may consult errno to get the exact error code.
+
+     The application must not modify the returned string.  Future calls to
+   this function may invalidate the previously returned string.  If file is
+   closed, then the string previously returned by gzerror will no longer be
+   available.
+
+     gzerror() should be used to distinguish errors from end-of-file for those
+   functions above that do not distinguish those cases in their return values.
+*/
+
+ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
+/*
+     Clears the error and end-of-file flags for file.  This is analogous to the
+   clearerr() function in stdio.  This is useful for continuing to read a gzip
+   file that is being written concurrently.
+*/
+
+#endif /* !Z_SOLO */
+
+                        /* checksum functions */
+
+/*
+     These functions are not related to compression but are exported
+   anyway because they might be useful in applications using the compression
+   library.
+*/
+
+ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
+/*
+     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+   return the updated checksum.  If buf is Z_NULL, this function returns the
+   required initial value for the checksum.
+
+     An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
+   much faster.
+
+   Usage example:
+
+     uLong adler = adler32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       adler = adler32(adler, buffer, length);
+     }
+     if (adler != original_adler) error();
+*/
+
+ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
+                                    z_size_t len));
+/*
+     Same as adler32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
+                                          z_off_t len2));
+
+     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
+   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
+   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
+   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
+   that the z_off_t type (like off_t) is a signed integer.  If len2 is
+   negative, the result has no meaning or utility.
+*/
+
+ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
+/*
+     Update a running CRC-32 with the bytes buf[0..len-1] and return the
+   updated CRC-32.  If buf is Z_NULL, this function returns the required
+   initial value for the crc.  Pre- and post-conditioning (one's complement) is
+   performed within this function so it shouldn't be done by the application.
+
+   Usage example:
+
+     uLong crc = crc32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       crc = crc32(crc, buffer, length);
+     }
+     if (crc != original_crc) error();
+*/
+
+ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
+                                  z_size_t len));
+/*
+     Same as crc32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
+
+     Combine two CRC-32 check values into one.  For two sequences of bytes,
+   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
+   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
+   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
+   len2.
+*/
+
+
+                        /* various hacks, don't look :) */
+
+/* deflateInit and inflateInit are macros to allow checking the zlib version
+ * and the compiler's view of z_stream:
+ */
+ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
+                                     const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
+                                     const char *version, int stream_size));
+ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
+                                      int windowBits, int memLevel,
+                                      int strategy, const char *version,
+                                      int stream_size));
+ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
+                                      const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
+                                         unsigned char FAR *window,
+                                         const char *version,
+                                         int stream_size));
+#ifdef Z_PREFIX_SET
+#  define z_deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define z_inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#else
+#  define deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#endif
+
+#ifndef Z_SOLO
+
+/* gzgetc() macro and its supporting function and exposed data structure.  Note
+ * that the real internal state is much larger than the exposed structure.
+ * This abbreviated structure exposes just enough for the gzgetc() macro.  The
+ * user should not mess with these exposed elements, since their names or
+ * behavior could change in the future, perhaps even capriciously.  They can
+ * only be used by the gzgetc() macro.  You have been warned.
+ */
+struct gzFile_s {
+    unsigned have;
+    unsigned char *next;
+    z_off64_t pos;
+};
+ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
+#ifdef Z_PREFIX_SET
+#  undef z_gzgetc
+#  define z_gzgetc(g) \
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#else
+#  define gzgetc(g) \
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#endif
+
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#ifdef Z_LARGE64
+   ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
+   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
+#endif
+
+#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
+#  ifdef Z_PREFIX_SET
+#    define z_gzopen z_gzopen64
+#    define z_gzseek z_gzseek64
+#    define z_gztell z_gztell64
+#    define z_gzoffset z_gzoffset64
+#    define z_adler32_combine z_adler32_combine64
+#    define z_crc32_combine z_crc32_combine64
+#  else
+#    define gzopen gzopen64
+#    define gzseek gzseek64
+#    define gztell gztell64
+#    define gzoffset gzoffset64
+#    define adler32_combine adler32_combine64
+#    define crc32_combine crc32_combine64
+#  endif
+#  ifndef Z_LARGE64
+     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
+     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
+     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
+     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
+#  endif
+#else
+   ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
+   ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
+   ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
+   ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+#endif
+
+#else /* Z_SOLO */
+
+   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+
+#endif /* !Z_SOLO */
+
+/* undocumented functions */
+ZEXTERN const char   * ZEXPORT zError           OF((int));
+ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
+ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
+ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
+ZEXTERN int            ZEXPORT inflateValidate OF((z_streamp, int));
+ZEXTERN unsigned long  ZEXPORT inflateCodesUsed OF ((z_streamp));
+ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
+ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
+#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
+ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
+                                            const char *mode));
+#endif
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file,
+                                                  const char *format,
+                                                  va_list va));
+#  endif
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZLIB_H */
diff --git a/xs/src/png/zlib/zlib.map b/xs/src/png/zlib/zlib.map
new file mode 100644
index 000000000..82ce98cf7
--- /dev/null
+++ b/xs/src/png/zlib/zlib.map
@@ -0,0 +1,94 @@
+ZLIB_1.2.0 {
+  global:
+    compressBound;
+    deflateBound;
+    inflateBack;
+    inflateBackEnd;
+    inflateBackInit_;
+    inflateCopy;
+  local:
+    deflate_copyright;
+    inflate_copyright;
+    inflate_fast;
+    inflate_table;
+    zcalloc;
+    zcfree;
+    z_errmsg;
+    gz_error;
+    gz_intmax;
+    _*;
+};
+
+ZLIB_1.2.0.2 {
+    gzclearerr;
+    gzungetc;
+    zlibCompileFlags;
+} ZLIB_1.2.0;
+
+ZLIB_1.2.0.8 {
+    deflatePrime;
+} ZLIB_1.2.0.2;
+
+ZLIB_1.2.2 {
+    adler32_combine;
+    crc32_combine;
+    deflateSetHeader;
+    inflateGetHeader;
+} ZLIB_1.2.0.8;
+
+ZLIB_1.2.2.3 {
+    deflateTune;
+    gzdirect;
+} ZLIB_1.2.2;
+
+ZLIB_1.2.2.4 {
+    inflatePrime;
+} ZLIB_1.2.2.3;
+
+ZLIB_1.2.3.3 {
+    adler32_combine64;
+    crc32_combine64;
+    gzopen64;
+    gzseek64;
+    gztell64;
+    inflateUndermine;
+} ZLIB_1.2.2.4;
+
+ZLIB_1.2.3.4 {
+    inflateReset2;
+    inflateMark;
+} ZLIB_1.2.3.3;
+
+ZLIB_1.2.3.5 {
+    gzbuffer;
+    gzoffset;
+    gzoffset64;
+    gzclose_r;
+    gzclose_w;
+} ZLIB_1.2.3.4;
+
+ZLIB_1.2.5.1 {
+    deflatePending;
+} ZLIB_1.2.3.5;
+
+ZLIB_1.2.5.2 {
+    deflateResetKeep;
+    gzgetc_;
+    inflateResetKeep;
+} ZLIB_1.2.5.1;
+
+ZLIB_1.2.7.1 {
+    inflateGetDictionary;
+    gzvprintf;
+} ZLIB_1.2.5.2;
+
+ZLIB_1.2.9 {
+    inflateCodesUsed;
+    inflateValidate;
+    uncompress2;
+    gzfread;
+    gzfwrite;
+    deflateGetDictionary;
+    adler32_z;
+    crc32_z;
+} ZLIB_1.2.7.1;
diff --git a/xs/src/png/zlib/zlib.pc.cmakein b/xs/src/png/zlib/zlib.pc.cmakein
new file mode 100644
index 000000000..a5e642938
--- /dev/null
+++ b/xs/src/png/zlib/zlib.pc.cmakein
@@ -0,0 +1,13 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=@CMAKE_INSTALL_PREFIX@
+libdir=@INSTALL_LIB_DIR@
+sharedlibdir=@INSTALL_LIB_DIR@
+includedir=@INSTALL_INC_DIR@
+
+Name: zlib
+Description: zlib compression library
+Version: @VERSION@
+
+Requires:
+Libs: -L${libdir} -L${sharedlibdir} -lz
+Cflags: -I${includedir}
diff --git a/xs/src/png/zlib/zlib.pc.in b/xs/src/png/zlib/zlib.pc.in
new file mode 100644
index 000000000..7e5acf9c7
--- /dev/null
+++ b/xs/src/png/zlib/zlib.pc.in
@@ -0,0 +1,13 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+sharedlibdir=@sharedlibdir@
+includedir=@includedir@
+
+Name: zlib
+Description: zlib compression library
+Version: @VERSION@
+
+Requires:
+Libs: -L${libdir} -L${sharedlibdir} -lz
+Cflags: -I${includedir}
diff --git a/xs/src/png/zlib/zlib2ansi b/xs/src/png/zlib/zlib2ansi
new file mode 100644
index 000000000..15e3e165f
--- /dev/null
+++ b/xs/src/png/zlib/zlib2ansi
@@ -0,0 +1,152 @@
+#!/usr/bin/perl
+
+# Transform K&R C function definitions into ANSI equivalent.
+#
+# Author: Paul Marquess
+# Version: 1.0
+# Date: 3 October 2006
+
+# TODO
+#
+# Asumes no function pointer parameters. unless they are typedefed.
+# Assumes no literal strings that look like function definitions
+# Assumes functions start at the beginning of a line
+
+use strict;
+use warnings;
+
+local $/;
+$_ = <>;
+
+my $sp = qr{ \s* (?: /\* .*? \*/ )? \s* }x; # assume no nested comments
+
+my $d1    = qr{ $sp (?: [\w\*\s]+ $sp)* $sp \w+ $sp [\[\]\s]* $sp }x ;
+my $decl  = qr{ $sp (?: \w+ $sp )+ $d1 }xo ;
+my $dList = qr{ $sp $decl (?: $sp , $d1 )* $sp ; $sp }xo ;
+
+
+while (s/^
+            (                  # Start $1
+                (              #   Start $2
+                    .*?        #     Minimal eat content
+                    ( ^ \w [\w\s\*]+ )    #     $3 -- function name
+                    \s*        #     optional whitespace
+                )              # $2 - Matched up to before parameter list
+
+                \( \s*         # Literal "(" + optional whitespace
+                ( [^\)]+ )     # $4 - one or more anythings except ")"
+                \s* \)         # optional whitespace surrounding a Literal ")"
+
+                ( (?: $dList )+ ) # $5
+
+                $sp ^ {        # literal "{" at start of line
+            )                  # Remember to $1
+        //xsom
+      )
+{
+    my $all = $1 ;
+    my $prefix = $2;
+    my $param_list = $4 ;
+    my $params = $5;
+
+    StripComments($params);
+    StripComments($param_list);
+    $param_list =~ s/^\s+//;
+    $param_list =~ s/\s+$//;
+
+    my $i = 0 ;
+    my %pList = map { $_ => $i++ }
+                split /\s*,\s*/, $param_list;
+    my $pMatch = '(\b' . join('|', keys %pList) . '\b)\W*$' ;
+
+    my @params = split /\s*;\s*/, $params;
+    my @outParams = ();
+    foreach my $p (@params)
+    {
+        if ($p =~ /,/)
+        {
+            my @bits = split /\s*,\s*/, $p;
+            my $first = shift @bits;
+            $first =~ s/^\s*//;
+            push @outParams, $first;
+            $first =~ /^(\w+\s*)/;
+            my $type = $1 ;
+            push @outParams, map { $type . $_ } @bits;
+        }
+        else
+        {
+            $p =~ s/^\s+//;
+            push @outParams, $p;
+        }
+    }
+
+
+    my %tmp = map { /$pMatch/;  $_ => $pList{$1}  }
+              @outParams ;
+
+    @outParams = map  { "    $_" }
+                 sort { $tmp{$a} <=> $tmp{$b} }
+                 @outParams ;
+
+    print $prefix ;
+    print "(\n" . join(",\n", @outParams) . ")\n";
+    print "{" ;
+
+}
+
+# Output any trailing code.
+print ;
+exit 0;
+
+
+sub StripComments
+{
+
+  no warnings;
+
+  # Strip C & C++ coments
+  # From the perlfaq
+  $_[0] =~
+
+    s{
+       /\*         ##  Start of /* ... */ comment
+       [^*]*\*+    ##  Non-* followed by 1-or-more *'s
+       (
+         [^/*][^*]*\*+
+       )*          ##  0-or-more things which don't start with /
+                   ##    but do end with '*'
+       /           ##  End of /* ... */ comment
+
+     |         ##     OR  C++ Comment
+       //          ## Start of C++ comment //
+       [^\n]*      ## followed by 0-or-more non end of line characters
+
+     |         ##     OR  various things which aren't comments:
+
+       (
+         "           ##  Start of " ... " string
+         (
+           \\.           ##  Escaped char
+         |               ##    OR
+           [^"\\]        ##  Non "\
+         )*
+         "           ##  End of " ... " string
+
+       |         ##     OR
+
+         '           ##  Start of ' ... ' string
+         (
+           \\.           ##  Escaped char
+         |               ##    OR
+           [^'\\]        ##  Non '\
+         )*
+         '           ##  End of ' ... ' string
+
+       |         ##     OR
+
+         .           ##  Anything other char
+         [^/"'\\]*   ##  Chars which doesn't start a comment, string or escape
+       )
+     }{$2}gxs;
+
+}
diff --git a/xs/src/png/zlib/zutil.c b/xs/src/png/zlib/zutil.c
new file mode 100644
index 000000000..a76c6b0c7
--- /dev/null
+++ b/xs/src/png/zlib/zutil.c
@@ -0,0 +1,325 @@
+/* zutil.c -- target dependent utility functions for the compression library
+ * Copyright (C) 1995-2017 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zutil.h"
+#ifndef Z_SOLO
+#  include "gzguts.h"
+#endif
+
+z_const char * const z_errmsg[10] = {
+    (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
+    (z_const char *)"stream end",          /* Z_STREAM_END      1  */
+    (z_const char *)"",                    /* Z_OK              0  */
+    (z_const char *)"file error",          /* Z_ERRNO         (-1) */
+    (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
+    (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
+    (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
+    (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
+    (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
+    (z_const char *)""
+};
+
+
+const char * ZEXPORT zlibVersion()
+{
+    return ZLIB_VERSION;
+}
+
+uLong ZEXPORT zlibCompileFlags()
+{
+    uLong flags;
+
+    flags = 0;
+    switch ((int)(sizeof(uInt))) {
+    case 2:     break;
+    case 4:     flags += 1;     break;
+    case 8:     flags += 2;     break;
+    default:    flags += 3;
+    }
+    switch ((int)(sizeof(uLong))) {
+    case 2:     break;
+    case 4:     flags += 1 << 2;        break;
+    case 8:     flags += 2 << 2;        break;
+    default:    flags += 3 << 2;
+    }
+    switch ((int)(sizeof(voidpf))) {
+    case 2:     break;
+    case 4:     flags += 1 << 4;        break;
+    case 8:     flags += 2 << 4;        break;
+    default:    flags += 3 << 4;
+    }
+    switch ((int)(sizeof(z_off_t))) {
+    case 2:     break;
+    case 4:     flags += 1 << 6;        break;
+    case 8:     flags += 2 << 6;        break;
+    default:    flags += 3 << 6;
+    }
+#ifdef ZLIB_DEBUG
+    flags += 1 << 8;
+#endif
+#if defined(ASMV) || defined(ASMINF)
+    flags += 1 << 9;
+#endif
+#ifdef ZLIB_WINAPI
+    flags += 1 << 10;
+#endif
+#ifdef BUILDFIXED
+    flags += 1 << 12;
+#endif
+#ifdef DYNAMIC_CRC_TABLE
+    flags += 1 << 13;
+#endif
+#ifdef NO_GZCOMPRESS
+    flags += 1L << 16;
+#endif
+#ifdef NO_GZIP
+    flags += 1L << 17;
+#endif
+#ifdef PKZIP_BUG_WORKAROUND
+    flags += 1L << 20;
+#endif
+#ifdef FASTEST
+    flags += 1L << 21;
+#endif
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifdef NO_vsnprintf
+    flags += 1L << 25;
+#    ifdef HAS_vsprintf_void
+    flags += 1L << 26;
+#    endif
+#  else
+#    ifdef HAS_vsnprintf_void
+    flags += 1L << 26;
+#    endif
+#  endif
+#else
+    flags += 1L << 24;
+#  ifdef NO_snprintf
+    flags += 1L << 25;
+#    ifdef HAS_sprintf_void
+    flags += 1L << 26;
+#    endif
+#  else
+#    ifdef HAS_snprintf_void
+    flags += 1L << 26;
+#    endif
+#  endif
+#endif
+    return flags;
+}
+
+#ifdef ZLIB_DEBUG
+#include <stdlib.h>
+#  ifndef verbose
+#    define verbose 0
+#  endif
+int ZLIB_INTERNAL z_verbose = verbose;
+
+void ZLIB_INTERNAL z_error (m)
+    char *m;
+{
+    fprintf(stderr, "%s\n", m);
+    exit(1);
+}
+#endif
+
+/* exported to allow conversion of error code to string for compress() and
+ * uncompress()
+ */
+const char * ZEXPORT zError(err)
+    int err;
+{
+    return ERR_MSG(err);
+}
+
+#if defined(_WIN32_WCE)
+    /* The Microsoft C Run-Time Library for Windows CE doesn't have
+     * errno.  We define it as a global variable to simplify porting.
+     * Its value is always 0 and should not be used.
+     */
+    int errno = 0;
+#endif
+
+#ifndef HAVE_MEMCPY
+
+void ZLIB_INTERNAL zmemcpy(dest, source, len)
+    Bytef* dest;
+    const Bytef* source;
+    uInt  len;
+{
+    if (len == 0) return;
+    do {
+        *dest++ = *source++; /* ??? to be unrolled */
+    } while (--len != 0);
+}
+
+int ZLIB_INTERNAL zmemcmp(s1, s2, len)
+    const Bytef* s1;
+    const Bytef* s2;
+    uInt  len;
+{
+    uInt j;
+
+    for (j = 0; j < len; j++) {
+        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
+    }
+    return 0;
+}
+
+void ZLIB_INTERNAL zmemzero(dest, len)
+    Bytef* dest;
+    uInt  len;
+{
+    if (len == 0) return;
+    do {
+        *dest++ = 0;  /* ??? to be unrolled */
+    } while (--len != 0);
+}
+#endif
+
+#ifndef Z_SOLO
+
+#ifdef SYS16BIT
+
+#ifdef __TURBOC__
+/* Turbo C in 16-bit mode */
+
+#  define MY_ZCALLOC
+
+/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
+ * and farmalloc(64K) returns a pointer with an offset of 8, so we
+ * must fix the pointer. Warning: the pointer must be put back to its
+ * original form in order to free it, use zcfree().
+ */
+
+#define MAX_PTR 10
+/* 10*64K = 640K */
+
+local int next_ptr = 0;
+
+typedef struct ptr_table_s {
+    voidpf org_ptr;
+    voidpf new_ptr;
+} ptr_table;
+
+local ptr_table table[MAX_PTR];
+/* This table is used to remember the original form of pointers
+ * to large buffers (64K). Such pointers are normalized with a zero offset.
+ * Since MSDOS is not a preemptive multitasking OS, this table is not
+ * protected from concurrent access. This hack doesn't work anyway on
+ * a protected system like OS/2. Use Microsoft C instead.
+ */
+
+voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
+{
+    voidpf buf;
+    ulg bsize = (ulg)items*size;
+
+    (void)opaque;
+
+    /* If we allocate less than 65520 bytes, we assume that farmalloc
+     * will return a usable pointer which doesn't have to be normalized.
+     */
+    if (bsize < 65520L) {
+        buf = farmalloc(bsize);
+        if (*(ush*)&buf != 0) return buf;
+    } else {
+        buf = farmalloc(bsize + 16L);
+    }
+    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
+    table[next_ptr].org_ptr = buf;
+
+    /* Normalize the pointer to seg:0 */
+    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
+    *(ush*)&buf = 0;
+    table[next_ptr++].new_ptr = buf;
+    return buf;
+}
+
+void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
+{
+    int n;
+
+    (void)opaque;
+
+    if (*(ush*)&ptr != 0) { /* object < 64K */
+        farfree(ptr);
+        return;
+    }
+    /* Find the original pointer */
+    for (n = 0; n < next_ptr; n++) {
+        if (ptr != table[n].new_ptr) continue;
+
+        farfree(table[n].org_ptr);
+        while (++n < next_ptr) {
+            table[n-1] = table[n];
+        }
+        next_ptr--;
+        return;
+    }
+    Assert(0, "zcfree: ptr not found");
+}
+
+#endif /* __TURBOC__ */
+
+
+#ifdef M_I86
+/* Microsoft C in 16-bit mode */
+
+#  define MY_ZCALLOC
+
+#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
+#  define _halloc  halloc
+#  define _hfree   hfree
+#endif
+
+voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
+{
+    (void)opaque;
+    return _halloc((long)items, size);
+}
+
+void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
+{
+    (void)opaque;
+    _hfree(ptr);
+}
+
+#endif /* M_I86 */
+
+#endif /* SYS16BIT */
+
+
+#ifndef MY_ZCALLOC /* Any system without a special alloc function */
+
+#ifndef STDC
+extern voidp  malloc OF((uInt size));
+extern voidp  calloc OF((uInt items, uInt size));
+extern void   free   OF((voidpf ptr));
+#endif
+
+voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
+    voidpf opaque;
+    unsigned items;
+    unsigned size;
+{
+    (void)opaque;
+    return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
+                              (voidpf)calloc(items, size);
+}
+
+void ZLIB_INTERNAL zcfree (opaque, ptr)
+    voidpf opaque;
+    voidpf ptr;
+{
+    (void)opaque;
+    free(ptr);
+}
+
+#endif /* MY_ZCALLOC */
+
+#endif /* !Z_SOLO */
diff --git a/xs/src/png/zlib/zutil.h b/xs/src/png/zlib/zutil.h
new file mode 100644
index 000000000..b079ea6a8
--- /dev/null
+++ b/xs/src/png/zlib/zutil.h
@@ -0,0 +1,271 @@
+/* zutil.h -- internal interface and configuration of the compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZUTIL_H
+#define ZUTIL_H
+
+#ifdef HAVE_HIDDEN
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
+#include "zlib.h"
+
+#if defined(STDC) && !defined(Z_SOLO)
+#  if !(defined(_WIN32_WCE) && defined(_MSC_VER))
+#    include <stddef.h>
+#  endif
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+
+#ifdef Z_SOLO
+   typedef long ptrdiff_t;  /* guess -- will be caught if guess is wrong */
+#endif
+
+#ifndef local
+#  define local static
+#endif
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
+
+typedef unsigned char  uch;
+typedef uch FAR uchf;
+typedef unsigned short ush;
+typedef ush FAR ushf;
+typedef unsigned long  ulg;
+
+extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
+/* (size given to avoid silly warnings with Visual C++) */
+
+#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
+
+#define ERR_RETURN(strm,err) \
+  return (strm->msg = ERR_MSG(err), (err))
+/* To be used only when the state is known to be valid */
+
+        /* common constants */
+
+#ifndef DEF_WBITS
+#  define DEF_WBITS MAX_WBITS
+#endif
+/* default windowBits for decompression. MAX_WBITS is for compression only */
+
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+/* default memLevel */
+
+#define STORED_BLOCK 0
+#define STATIC_TREES 1
+#define DYN_TREES    2
+/* The three kinds of block type */
+
+#define MIN_MATCH  3
+#define MAX_MATCH  258
+/* The minimum and maximum match lengths */
+
+#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
+
+        /* target dependencies */
+
+#if defined(MSDOS) || (defined(WINDOWS) && !defined(WIN32))
+#  define OS_CODE  0x00
+#  ifndef Z_SOLO
+#    if defined(__TURBOC__) || defined(__BORLANDC__)
+#      if (__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
+         /* Allow compilation with ANSI keywords only enabled */
+         void _Cdecl farfree( void *block );
+         void *_Cdecl farmalloc( unsigned long nbytes );
+#      else
+#        include <alloc.h>
+#      endif
+#    else /* MSC or DJGPP */
+#      include <malloc.h>
+#    endif
+#  endif
+#endif
+
+#ifdef AMIGA
+#  define OS_CODE  1
+#endif
+
+#if defined(VAXC) || defined(VMS)
+#  define OS_CODE  2
+#  define F_OPEN(name, mode) \
+     fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
+#endif
+
+#ifdef __370__
+#  if __TARGET_LIB__ < 0x20000000
+#    define OS_CODE 4
+#  elif __TARGET_LIB__ < 0x40000000
+#    define OS_CODE 11
+#  else
+#    define OS_CODE 8
+#  endif
+#endif
+
+#if defined(ATARI) || defined(atarist)
+#  define OS_CODE  5
+#endif
+
+#ifdef OS2
+#  define OS_CODE  6
+#  if defined(M_I86) && !defined(Z_SOLO)
+#    include <malloc.h>
+#  endif
+#endif
+
+#if defined(MACOS) || defined(TARGET_OS_MAC)
+#  define OS_CODE  7
+#  ifndef Z_SOLO
+#    if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
+#      include <unix.h> /* for fdopen */
+#    else
+#      ifndef fdopen
+#        define fdopen(fd,mode) NULL /* No fdopen() */
+#      endif
+#    endif
+#  endif
+#endif
+
+#ifdef __acorn
+#  define OS_CODE 13
+#endif
+
+#if defined(WIN32) && !defined(__CYGWIN__)
+#  define OS_CODE  10
+#endif
+
+#ifdef _BEOS_
+#  define OS_CODE  16
+#endif
+
+#ifdef __TOS_OS400__
+#  define OS_CODE 18
+#endif
+
+#ifdef __APPLE__
+#  define OS_CODE 19
+#endif
+
+#if defined(_BEOS_) || defined(RISCOS)
+#  define fdopen(fd,mode) NULL /* No fdopen() */
+#endif
+
+#if (defined(_MSC_VER) && (_MSC_VER > 600)) && !defined __INTERIX
+#  if defined(_WIN32_WCE)
+#    define fdopen(fd,mode) NULL /* No fdopen() */
+#    ifndef _PTRDIFF_T_DEFINED
+       typedef int ptrdiff_t;
+#      define _PTRDIFF_T_DEFINED
+#    endif
+#  else
+#    define fdopen(fd,type)  _fdopen(fd,type)
+#  endif
+#endif
+
+#if defined(__BORLANDC__) && !defined(MSDOS)
+  #pragma warn -8004
+  #pragma warn -8008
+  #pragma warn -8066
+#endif
+
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_WIN32) && \
+    (!defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0)
+    ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+    ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
+#endif
+
+        /* common defaults */
+
+#ifndef OS_CODE
+#  define OS_CODE  3     /* assume Unix */
+#endif
+
+#ifndef F_OPEN
+#  define F_OPEN(name, mode) fopen((name), (mode))
+#endif
+
+         /* functions */
+
+#if defined(pyr) || defined(Z_SOLO)
+#  define NO_MEMCPY
+#endif
+#if defined(SMALL_MEDIUM) && !defined(_MSC_VER) && !defined(__SC__)
+ /* Use our own functions for small and medium model with MSC <= 5.0.
+  * You may have to use the same strategy for Borland C (untested).
+  * The __SC__ check is for Symantec.
+  */
+#  define NO_MEMCPY
+#endif
+#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
+#  define HAVE_MEMCPY
+#endif
+#ifdef HAVE_MEMCPY
+#  ifdef SMALL_MEDIUM /* MSDOS small or medium model */
+#    define zmemcpy _fmemcpy
+#    define zmemcmp _fmemcmp
+#    define zmemzero(dest, len) _fmemset(dest, 0, len)
+#  else
+#    define zmemcpy memcpy
+#    define zmemcmp memcmp
+#    define zmemzero(dest, len) memset(dest, 0, len)
+#  endif
+#else
+   void ZLIB_INTERNAL zmemcpy OF((Bytef* dest, const Bytef* source, uInt len));
+   int ZLIB_INTERNAL zmemcmp OF((const Bytef* s1, const Bytef* s2, uInt len));
+   void ZLIB_INTERNAL zmemzero OF((Bytef* dest, uInt len));
+#endif
+
+/* Diagnostic functions */
+#ifdef ZLIB_DEBUG
+#  include <stdio.h>
+   extern int ZLIB_INTERNAL z_verbose;
+   extern void ZLIB_INTERNAL z_error OF((char *m));
+#  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
+#  define Trace(x) {if (z_verbose>=0) fprintf x ;}
+#  define Tracev(x) {if (z_verbose>0) fprintf x ;}
+#  define Tracevv(x) {if (z_verbose>1) fprintf x ;}
+#  define Tracec(c,x) {if (z_verbose>0 && (c)) fprintf x ;}
+#  define Tracecv(c,x) {if (z_verbose>1 && (c)) fprintf x ;}
+#else
+#  define Assert(cond,msg)
+#  define Trace(x)
+#  define Tracev(x)
+#  define Tracevv(x)
+#  define Tracec(c,x)
+#  define Tracecv(c,x)
+#endif
+
+#ifndef Z_SOLO
+   voidpf ZLIB_INTERNAL zcalloc OF((voidpf opaque, unsigned items,
+                                    unsigned size));
+   void ZLIB_INTERNAL zcfree  OF((voidpf opaque, voidpf ptr));
+#endif
+
+#define ZALLOC(strm, items, size) \
+           (*((strm)->zalloc))((strm)->opaque, (items), (size))
+#define ZFREE(strm, addr)  (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
+#define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
+
+/* Reverse the bytes in a 32-bit value */
+#define ZSWAP32(q) ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
+                    (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
+
+#endif /* ZUTIL_H */