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Diffstat (limited to 'src/agg/agg_bezier_arc.h')
| -rw-r--r-- | src/agg/agg_bezier_arc.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/agg/agg_bezier_arc.h b/src/agg/agg_bezier_arc.h new file mode 100644 index 000000000..cfd9308ea --- /dev/null +++ b/src/agg/agg_bezier_arc.h @@ -0,0 +1,159 @@ +//---------------------------------------------------------------------------- +// 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 generator. Produces at most 4 consecutive cubic bezier curves, i.e., +// 4, 7, 10, or 13 vertices. +// +//---------------------------------------------------------------------------- + +#ifndef AGG_BEZIER_ARC_INCLUDED +#define AGG_BEZIER_ARC_INCLUDED + +#include "agg_conv_transform.h" + +namespace agg +{ + + //----------------------------------------------------------------------- + void arc_to_bezier(double cx, double cy, double rx, double ry, + double start_angle, double sweep_angle, + double* curve); + + + //==============================================================bezier_arc + // + // See implemantaion agg_bezier_arc.cpp + // + class bezier_arc + { + public: + //-------------------------------------------------------------------- + bezier_arc() : m_vertex(26), m_num_vertices(0), m_cmd(path_cmd_line_to) {} + bezier_arc(double x, double y, + double rx, double ry, + double start_angle, + double sweep_angle) + { + init(x, y, rx, ry, start_angle, sweep_angle); + } + + //-------------------------------------------------------------------- + void init(double x, double y, + double rx, double ry, + double start_angle, + double sweep_angle); + + //-------------------------------------------------------------------- + void rewind(unsigned) + { + m_vertex = 0; + } + + //-------------------------------------------------------------------- + unsigned vertex(double* x, double* y) + { + if(m_vertex >= m_num_vertices) return path_cmd_stop; + *x = m_vertices[m_vertex]; + *y = m_vertices[m_vertex + 1]; + m_vertex += 2; + return (m_vertex == 2) ? unsigned(path_cmd_move_to) : m_cmd; + } + + // Supplemantary functions. num_vertices() actually returns doubled + // number of vertices. That is, for 1 vertex it returns 2. + //-------------------------------------------------------------------- + unsigned num_vertices() const { return m_num_vertices; } + const double* vertices() const { return m_vertices; } + double* vertices() { return m_vertices; } + + private: + unsigned m_vertex; + unsigned m_num_vertices; + double m_vertices[26]; + unsigned m_cmd; + }; + + + + //==========================================================bezier_arc_svg + // Compute an SVG-style bezier arc. + // + // Computes an elliptical arc from (x1, y1) to (x2, y2). The size and + // orientation of the ellipse are defined by two radii (rx, ry) + // and an x-axis-rotation, which indicates how the ellipse as a whole + // is rotated relative to the current coordinate system. The center + // (cx, cy) of the ellipse is calculated automatically to satisfy the + // constraints imposed by the other parameters. + // large-arc-flag and sweep-flag contribute to the automatic calculations + // and help determine how the arc is drawn. + class bezier_arc_svg + { + public: + //-------------------------------------------------------------------- + bezier_arc_svg() : m_arc(), m_radii_ok(false) {} + + bezier_arc_svg(double x1, double y1, + double rx, double ry, + double angle, + bool large_arc_flag, + bool sweep_flag, + double x2, double y2) : + m_arc(), m_radii_ok(false) + { + init(x1, y1, rx, ry, angle, large_arc_flag, sweep_flag, x2, y2); + } + + //-------------------------------------------------------------------- + void init(double x1, double y1, + double rx, double ry, + double angle, + bool large_arc_flag, + bool sweep_flag, + double x2, double y2); + + //-------------------------------------------------------------------- + bool radii_ok() const { return m_radii_ok; } + + //-------------------------------------------------------------------- + void rewind(unsigned) + { + m_arc.rewind(0); + } + + //-------------------------------------------------------------------- + unsigned vertex(double* x, double* y) + { + return m_arc.vertex(x, y); + } + + // Supplemantary functions. num_vertices() actually returns doubled + // number of vertices. That is, for 1 vertex it returns 2. + //-------------------------------------------------------------------- + unsigned num_vertices() const { return m_arc.num_vertices(); } + const double* vertices() const { return m_arc.vertices(); } + double* vertices() { return m_arc.vertices(); } + + private: + bezier_arc m_arc; + bool m_radii_ok; + }; + + + + +} + + +#endif |