aseprite/src/gfx/rgb.cpp

83 lines
1.4 KiB
C++

// Aseprite Gfx Library
// Copyright (C) 2001-2013 David Capello
//
// This file is released under the terms of the MIT license.
// Read LICENSE.txt for more information.
#include "gfx/rgb.h"
#include "gfx/hsv.h"
#include <cmath>
namespace gfx {
using namespace std;
// Reference: http://en.wikipedia.org/wiki/HSL_and_HSV
Rgb::Rgb(const Hsv& hsv)
{
double chroma = hsv.value() * hsv.saturation();
double hue_prime = hsv.hue() / 60.0;
double x = chroma * (1.0 - fabs(fmod(hue_prime, 2.0) - 1.0));
double r, g, b;
r = g = b = 0.0;
switch (int(hue_prime)) {
case 6:
case 0:
r = chroma;
g = x;
break;
case 1:
r = x;
g = chroma;
break;
case 2:
g = chroma;
b = x;
break;
case 3:
g = x;
b = chroma;
break;
case 4:
b = chroma;
r = x;
break;
case 5:
b = x;
r = chroma;
break;
}
double m = hsv.value() - chroma;
r += m;
g += m;
b += m;
m_red = int(r*255.0+0.5);
m_green = int(g*255.0+0.5);
m_blue = int(b*255.0+0.5);
}
int Rgb::maxComponent() const
{
if (m_red > m_green)
return (m_red > m_blue) ? m_red: m_blue;
else
return (m_green > m_blue) ? m_green: m_blue;
}
int Rgb::minComponent() const
{
if (m_red < m_green)
return (m_red < m_blue) ? m_red: m_blue;
else
return (m_green < m_blue) ? m_green: m_blue;
}
} // namespace gfx