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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_GRADIENT_INCLUDED
#define AGG_SPAN_GRADIENT_INCLUDED
#include <math.h>
#include <stdlib.h>
#include "agg_basics.h"
#include "agg_span_generator.h"
#include "agg_math.h"
namespace agg
{
//==========================================================span_gradient
template<class ColorT,
class Interpolator,
class GradientF,
class ColorF,
class Allocator = span_allocator<ColorT> >
class span_gradient : public span_generator<ColorT, Allocator>
{
public:
typedef Interpolator interpolator_type;
typedef Allocator alloc_type;
typedef ColorT color_type;
typedef span_generator<color_type, alloc_type> base_type;
enum
{
base_shift = 8,
base_size = 1 << base_shift,
base_mask = base_size - 1,
gradient_shift = 4,
gradient_size = 1 << gradient_shift,
gradient_mask = gradient_size - 1,
downscale_shift = interpolator_type::subpixel_shift - gradient_shift
};
//--------------------------------------------------------------------
span_gradient(alloc_type& alloc) : base_type(alloc) {}
//--------------------------------------------------------------------
span_gradient(alloc_type& alloc,
interpolator_type& inter,
const GradientF& gradient_function,
ColorF color_function,
double d1, double d2) :
base_type(alloc),
m_interpolator(&inter),
m_gradient_function(&gradient_function),
m_color_function(color_function),
m_d1(int(d1 * gradient_size)),
m_d2(int(d2 * gradient_size))
{}
//--------------------------------------------------------------------
interpolator_type& interpolator() { return *m_interpolator; }
const GradientF& gradient_function() const { return *m_gradient_function; }
const ColorF color_function() const { return m_color_function; }
double d1() const { return double(m_d1) / gradient_size; }
double d2() const { return double(m_d2) / gradient_size; }
//--------------------------------------------------------------------
void interpolator(interpolator_type& i) { m_interpolator = &i; }
void gradient_function(const GradientF& gf) { m_gradient_function = &gf; }
void color_function(ColorF cf) { m_color_function = cf; }
void d1(double v) { m_d1 = int(v * gradient_size); }
void d2(double v) { m_d2 = int(v * gradient_size); }
//--------------------------------------------------------------------
color_type* generate(int x, int y, unsigned len)
{
color_type* span = base_type::allocator().span();
int dd = m_d2 - m_d1;
if(dd < 1) dd = 1;
m_interpolator->begin(x+0.5, y+0.5, len);
do
{
m_interpolator->coordinates(&x, &y);
int d = m_gradient_function->calculate(x >> downscale_shift,
y >> downscale_shift, dd);
d = ((d - m_d1) << base_shift) / dd;
if(d < 0) d = 0;
if(d > base_mask) d = base_mask;
*span++ = m_color_function[d];
++(*m_interpolator);
}
while(--len);
return base_type::allocator().span();
}
private:
interpolator_type* m_interpolator;
const GradientF* m_gradient_function;
ColorF m_color_function;
int m_d1;
int m_d2;
};
//=====================================================gradient_linear_color
template<class ColorT, unsigned BaseShift=8>
struct gradient_linear_color
{
typedef ColorT color_type;
enum
{
base_shift = BaseShift,
base_size = 1 << base_shift,
base_mask = base_size - 1
};
gradient_linear_color() {}
gradient_linear_color(const color_type& c1, const color_type& c2) :
m_c1(c1), m_c2(c2) {}
color_type operator [] (unsigned v) const
{
return m_c1.gradient(m_c2, double(v) / double(base_mask));
}
void colors(const color_type& c1, const color_type& c2)
{
m_c1 = c1;
m_c2 = c2;
}
color_type m_c1;
color_type m_c2;
};
//---------------------------------------------------------gradient_circle
class gradient_circle
{
public:
static int calculate(int x, int y, int)
{
return int(fast_sqrt(x*x + y*y));
}
};
//--------------------------------------------------------------gradient_x
class gradient_x
{
public:
static int calculate(int x, int, int) { return x; }
};
//--------------------------------------------------------------gradient_y
class gradient_y
{
public:
static int calculate(int, int y, int) { return y; }
};
//--------------------------------------------------------gradient_diamond
class gradient_diamond
{
public:
static int calculate(int x, int y, int)
{
int ax = abs(x);
int ay = abs(y);
return ax > ay ? ax : ay;
}
};
//-------------------------------------------------------------gradient_xy
class gradient_xy
{
public:
static int calculate(int x, int y, int d)
{
return abs(x) * abs(y) / d;
}
};
//--------------------------------------------------------gradient_sqrt_xy
class gradient_sqrt_xy
{
public:
static int calculate(int x, int y, int)
{
return fast_sqrt(abs(x) * abs(y));
}
};
//----------------------------------------------------------gradient_conic
class gradient_conic
{
public:
static int calculate(int x, int y, int d)
{
return int(fabs(atan2(double(y), double(x))) * double(d) / pi);
}
};
}
#endif
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