132 lines
3.4 KiB
C++
132 lines
3.4 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_GAMMA_FUNCTIONS_INCLUDED
|
|
#define AGG_GAMMA_FUNCTIONS_INCLUDED
|
|
|
|
#include "agg_basics.h"
|
|
|
|
namespace agg
|
|
{
|
|
//===============================================================gamma_none
|
|
struct gamma_none
|
|
{
|
|
double operator()(double x) const { return x; }
|
|
};
|
|
|
|
|
|
//==============================================================gamma_power
|
|
class gamma_power
|
|
{
|
|
public:
|
|
gamma_power() : m_gamma(1.0) {}
|
|
gamma_power(double g) : m_gamma(g) {}
|
|
|
|
void gamma(double g) { m_gamma = g; }
|
|
double gamma() const { return m_gamma; }
|
|
|
|
double operator() (double x) const
|
|
{
|
|
return pow(x, m_gamma);
|
|
}
|
|
|
|
private:
|
|
double m_gamma;
|
|
};
|
|
|
|
|
|
//==========================================================gamma_threshold
|
|
class gamma_threshold
|
|
{
|
|
public:
|
|
gamma_threshold() : m_threshold(0.5) {}
|
|
gamma_threshold(double t) : m_threshold(t) {}
|
|
|
|
void threshold(double t) { m_threshold = t; }
|
|
double threshold() const { return m_threshold; }
|
|
|
|
double operator() (double x) const
|
|
{
|
|
return (x < m_threshold) ? 0.0 : 1.0;
|
|
}
|
|
|
|
private:
|
|
double m_threshold;
|
|
};
|
|
|
|
|
|
//============================================================gamma_linear
|
|
class gamma_linear
|
|
{
|
|
public:
|
|
gamma_linear() : m_start(0.0), m_end(1.0) {}
|
|
gamma_linear(double s, double e) : m_start(s), m_end(e) {}
|
|
|
|
void set(double s, double e) { m_start = s; m_end = e; }
|
|
void start(double s) { m_start = s; }
|
|
void end(double e) { m_end = e; }
|
|
double start() const { return m_start; }
|
|
double end() const { return m_end; }
|
|
|
|
double operator() (double x) const
|
|
{
|
|
if(x < m_start) return 0.0;
|
|
if(x > m_end) return 1.0;
|
|
return (x - m_start) / (m_end - m_start);
|
|
}
|
|
|
|
private:
|
|
double m_start;
|
|
double m_end;
|
|
};
|
|
|
|
|
|
//==========================================================gamma_multiply
|
|
class gamma_multiply
|
|
{
|
|
public:
|
|
gamma_multiply() : m_mul(1.0) {}
|
|
gamma_multiply(double v) : m_mul(v) {}
|
|
|
|
void value(double v) { m_mul = v; }
|
|
double value() const { return m_mul; }
|
|
|
|
double operator() (double x) const
|
|
{
|
|
double y = x * m_mul;
|
|
if(y > 1.0) y = 1.0;
|
|
return y;
|
|
}
|
|
|
|
private:
|
|
double m_mul;
|
|
};
|
|
|
|
inline double sRGB_to_linear(double x)
|
|
{
|
|
return (x <= 0.04045) ? (x / 12.92) : pow((x + 0.055) / (1.055), 2.4);
|
|
}
|
|
|
|
inline double linear_to_sRGB(double x)
|
|
{
|
|
return (x <= 0.0031308) ? (x * 12.92) : (1.055 * pow(x, 1 / 2.4) - 0.055);
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|