/usr/include/mapnik/agg/agg_span_gouraud.h is in libmapnik-dev 2.2.0+ds1-7+b2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | //----------------------------------------------------------------------------
// 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
|