rawTherapee/rtengine/satandvalueblendingcurve.h
2019-11-03 14:52:42 +01:00

71 lines
1.9 KiB
C++

/*
* This file is part of RawTherapee.
*
* Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
*
* RawTherapee is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* RawTherapee is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with RawTherapee. If not, see <https://www.gnu.org/licenses/>.
*/
#pragma once
#include "color.h"
#include "curves.h"
namespace rtengine
{
class SatAndValueBlendingToneCurve : public ToneCurve
{
public:
void Apply(float& r, float& g, float& b) const;
};
// Tone curve modifying the value channel only, preserving hue and saturation
// values in 0xffff space
inline void SatAndValueBlendingToneCurve::Apply (float& ir, float& ig, float& ib) const
{
assert (lutToneCurve);
float r = CLIP(ir);
float g = CLIP(ig);
float b = CLIP(ib);
const float lum = (r + g + b) / 3.f;
const float newLum = lutToneCurve[lum];
if (newLum == lum) {
return;
}
float h, s, v;
Color::rgb2hsvtc(r, g, b, h, s, v);
float dV;
if (newLum > lum) {
// Linearly targeting Value = 1 and Saturation = 0
const float coef = (newLum - lum) / (65535.f - lum);
dV = (1.f - v) * coef;
s *= 1.f - coef;
} else {
// Linearly targeting Value = 0
const float coef = (newLum - lum) / lum ;
dV = v * coef;
}
Color::hsv2rgbdcp(h, s, v + dV, r, g, b);
setUnlessOOG(ir, ig, ib, r, g, b);
}
}