e39da397f5
* removed the useless parts of AGG (which are only needed for the interactive examples) * make sure to jam -a libagg.a to solve any linking issues git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17838 a95241bf-73f2-0310-859d-f6bbb57e9c96
173 lines
5.6 KiB
C++
173 lines
5.6 KiB
C++
//----------------------------------------------------------------------------
|
|
// 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
|
|
|