hyperion.ng/libsrc/utils/ColorTransform.cpp
T. van der Zwan 3d02fecc7a Added 'rainbow' boot sequence
Moved color transform to utils lib
2013-08-23 16:24:10 +00:00

104 lines
1.7 KiB
C++

// STL includes
#include <cmath>
#include <utils/ColorTransform.h>
ColorTransform::ColorTransform() :
_threshold(0),
_gamma(1.0),
_blacklevel(0.0),
_whitelevel(1.0)
{
initializeMapping();
}
ColorTransform::ColorTransform(double threshold, double gamma, double blacklevel, double whitelevel) :
_threshold(threshold),
_gamma(gamma),
_blacklevel(blacklevel),
_whitelevel(whitelevel)
{
initializeMapping();
}
ColorTransform::~ColorTransform()
{
}
double ColorTransform::getThreshold() const
{
return _threshold;
}
void ColorTransform::setThreshold(double threshold)
{
_threshold = threshold;
initializeMapping();
}
double ColorTransform::getGamma() const
{
return _gamma;
}
void ColorTransform::setGamma(double gamma)
{
_gamma = gamma;
initializeMapping();
}
double ColorTransform::getBlacklevel() const
{
return _blacklevel;
}
void ColorTransform::setBlacklevel(double blacklevel)
{
_blacklevel = blacklevel;
initializeMapping();
}
double ColorTransform::getWhitelevel() const
{
return _whitelevel;
}
void ColorTransform::setWhitelevel(double whitelevel)
{
_whitelevel = whitelevel;
initializeMapping();
}
void ColorTransform::initializeMapping()
{
// initialize the mapping as a linear array
for (int i = 0; i < 256; ++i)
{
double output = i / 255.0;
// apply linear transform
if (output < _threshold)
{
output = 0.0;
}
// apply gamma correction
output = std::pow(output, _gamma);
// apply blacklevel and whitelevel
output = _blacklevel + (_whitelevel - _blacklevel) * output;
// calc mapping
int mappingValue = output * 255;
if (mappingValue < 0)
{
mappingValue = 0;
}
else if (mappingValue > 255)
{
mappingValue = 255;
}
_mapping[i] = mappingValue;
}
}