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Diffstat (limited to 'src/png/info.hpp')
| -rw-r--r-- | src/png/info.hpp | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/png/info.hpp b/src/png/info.hpp new file mode 100644 index 000000000..3f3cf09c3 --- /dev/null +++ b/src/png/info.hpp @@ -0,0 +1,186 @@ +/* + * Copyright (C) 2007,2008 Alex Shulgin + * + * This file is part of png++ the C++ wrapper for libpng. PNG++ is free + * software; the exact copying conditions are as follows: + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN + * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#ifndef PNGPP_INFO_HPP_INCLUDED +#define PNGPP_INFO_HPP_INCLUDED + +#include <cassert> +#include "info_base.hpp" +#include "image_info.hpp" + +namespace png +{ + + /** + * \brief Holds information about PNG image. Adapter class for IO + * image operations. + */ + class info + : public info_base, + public image_info + { + public: + info(io_base& io, png_struct* png) + : info_base(io, png) + { + } + + void read() + { + assert(m_png); + assert(m_info); + + png_read_info(m_png, m_info); + png_get_IHDR(m_png, + m_info, + & m_width, + & m_height, + reinterpret_cast< int* >(& m_bit_depth), + reinterpret_cast< int* >(& m_color_type), + reinterpret_cast< int* >(& m_interlace_type), + reinterpret_cast< int* >(& m_compression_type), + reinterpret_cast< int* >(& m_filter_type)); + + if (png_get_valid(m_png, m_info, chunk_PLTE) == chunk_PLTE) + { + png_color* colors = 0; + int count = 0; + png_get_PLTE(m_png, m_info, & colors, & count); + m_palette.assign(colors, colors + count); + } + +#ifdef PNG_tRNS_SUPPORTED + if (png_get_valid(m_png, m_info, chunk_tRNS) == chunk_tRNS) + { + if (m_color_type == color_type_palette) + { + int count; + byte* values; + if (png_get_tRNS(m_png, m_info, & values, & count, NULL) + != PNG_INFO_tRNS) + { + throw error("png_get_tRNS() failed"); + } + m_tRNS.assign(values, values + count); + } + } +#endif + +#ifdef PNG_gAMA_SUPPORTED + if (png_get_valid(m_png, m_info, chunk_gAMA) == chunk_gAMA) + { +#ifdef PNG_FLOATING_POINT_SUPPORTED + if (png_get_gAMA(m_png, m_info, &m_gamma) != PNG_INFO_gAMA) + { + throw error("png_get_gAMA() failed"); + } +#else + png_fixed_point gamma = 0; + if (png_get_gAMA_fixed(m_png, m_info, &gamma) != PNG_INFO_gAMA) + { + throw error("png_get_gAMA_fixed() failed"); + } + m_gamma = gamma / 100000.0; +#endif + } +#endif + } + + void write() const + { + assert(m_png); + assert(m_info); + + sync_ihdr(); + if (m_color_type == color_type_palette) + { + if (! m_palette.empty()) + { + png_set_PLTE(m_png, m_info, + const_cast< color* >(& m_palette[0]), + (int) m_palette.size()); + } + if (! m_tRNS.empty()) + { +#ifdef PNG_tRNS_SUPPORTED + png_set_tRNS(m_png, m_info, + const_cast< byte* >(& m_tRNS[0]), + m_tRNS.size(), + NULL); +#else + throw error("attempted to write tRNS chunk; recompile with PNG_tRNS_SUPPORTED"); +#endif + } + } + + if (m_gamma > 0) + { +#ifdef PNG_gAMA_SUPPORTED +#ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_gAMA(m_png, m_info, m_gamma); +#else + png_set_gAMA_fixed(m_png, m_info, + (png_fixed_point)(m_gamma * 100000)); +#endif +#else + throw error("attempted to write gAMA chunk; recompile with PNG_gAMA_SUPPORTED"); +#endif + } + + png_write_info(m_png, m_info); + } + + void update() + { + assert(m_png); + assert(m_info); + + sync_ihdr(); + png_read_update_info(m_png, m_info); + } + + protected: + void sync_ihdr(void) const + { + png_set_IHDR(m_png, + m_info, + m_width, + m_height, + m_bit_depth, + m_color_type, + m_interlace_type, + m_compression_type, + m_filter_type); + } + }; + +} // namespace png + +#endif // PNGPP_INFO_HPP_INCLUDED |