haiku/headers/libs/agg/agg_span_gouraud_rgba8_gamma.h

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//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.2
// Copyright (C) 2002-2004 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_RGBA8_GAMMA_INCLUDED
#define AGG_SPAN_GOURAUD_RGBA8_GAMMA_INCLUDED
#include "agg_basics.h"
#include "agg_color_rgba8.h"
#include "agg_dda_line.h"
#include "agg_span_gouraud.h"
#include "agg_gamma_lut.h"
namespace agg
{
//======================================================span_gouraud_rgba8
template<class Allocator = span_allocator<rgba8>,
class Gamma = gamma_lut<int8u, int16u, 8, 16> >
class span_gouraud_rgba8_gamma : public span_gouraud<rgba8, Allocator>
{
public:
typedef Allocator alloc_type;
typedef rgba8 color_type;
typedef span_gouraud<color_type, alloc_type> base_type;
typedef typename base_type::coord_type coord_type;
typedef Gamma gamma_type;
private:
//--------------------------------------------------------------------
struct rgba_calc
{
void init(const coord_type& c1, const coord_type& c2, const gamma_type& gamma)
{
m_x1 = c1.x;
m_y1 = c1.y;
m_dx = c2.x - c1.x;
m_dy = 1.0 / (c2.y - c1.y);
m_r1 = gamma.dir(c1.color.r);
m_g1 = gamma.dir(c1.color.g);
m_b1 = gamma.dir(c1.color.b);
m_a1 = c1.color.a;
m_dr = gamma.dir(c2.color.r) - m_r1;
m_dg = gamma.dir(c2.color.g) - m_g1;
m_db = gamma.dir(c2.color.b) - m_b1;
m_da = c2.color.a - m_a1;
}
void calc(int y)
{
double k = 0.0;
if(y > m_y1) k = (y - m_y1) * m_dy;
m_r = m_r1 + int(m_dr * k);
m_g = m_g1 + int(m_dg * k);
m_b = m_b1 + int(m_db * k);
m_a = m_a1 + int(m_da * k);
m_x = int(m_x1 + m_dx * k);
}
double m_x1;
double m_y1;
double m_dx;
double m_dy;
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_rgba8_gamma(alloc_type& alloc, const gamma_type& g) :
base_type(alloc), m_gamma(&g) {}
//--------------------------------------------------------------------
span_gouraud_rgba8_gamma(alloc_type& alloc,
const gamma_type& g,
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(alloc, c1, c2, c3, x1, y1, x2, y2, x3, y3, d),
m_gamma(&g)
{}
//--------------------------------------------------------------------
void gamma(const gamma_type& g) { m_gamma = &g; }
const gamma_type& gamma() const { return *m_gamma; }
//--------------------------------------------------------------------
void prepare(unsigned max_span_len)
{
base_type::prepare(max_span_len);
coord_type coord[3];
arrange_vertices(coord);
m_y2 = int(coord[1].y);
m_swap = calc_point_location(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_gamma);
m_rgba2.init(coord[0], coord[1], *m_gamma);
m_rgba3.init(coord[1], coord[2], *m_gamma);
}
//--------------------------------------------------------------------
color_type* generate(int x, int y, unsigned len)
{
m_rgba1.calc(y);
const rgba_calc* pc1 = &m_rgba1;
const rgba_calc* pc2 = &m_rgba2;
if(y < m_y2)
{
m_rgba2.calc(y+1);
}
else
{
m_rgba3.calc(y);
pc2 = &m_rgba3;
}
if(m_swap)
{
const rgba_calc* t = pc2;
pc2 = pc1;
pc1 = t;
}
int nx = pc1->m_x;
unsigned nlen = pc2->m_x - pc1->m_x + 1;
if(nlen < len) nlen = len;
dda_line_interpolator<8> r(pc1->m_r, pc2->m_r, nlen);
dda_line_interpolator<8> g(pc1->m_g, pc2->m_g, nlen);
dda_line_interpolator<8> b(pc1->m_b, pc2->m_b, nlen);
dda_line_interpolator<16> a(pc1->m_a, pc2->m_a, nlen);
if(nx < x)
{
unsigned d = unsigned(x - nx);
r += d;
g += d;
b += d;
a += d;
}
color_type* span = base_type::allocator().span();
do
{
span->r = m_gamma->inv(r.y());
span->g = m_gamma->inv(g.y());
span->b = m_gamma->inv(b.y());
span->a = a.y();
++r;
++g;
++b;
++a;
++span;
}
while(--len);
return base_type::allocator().span();
}
private:
const gamma_type* m_gamma;
bool m_swap;
int m_y2;
rgba_calc m_rgba1;
rgba_calc m_rgba2;
rgba_calc m_rgba3;
};
}
#endif