/*
 * Copyright 2011, Blender Foundation.
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor: 
 *		Jeroen Bakker 
 *		Monique Dewanchand
 */

#include "COM_MixOverlayOperation.h"

MixOverlayOperation::MixOverlayOperation() : MixBaseOperation()
{
	/* pass */
}

void MixOverlayOperation::executePixel(float *outputValue, float x, float y, PixelSampler sampler, MemoryBuffer *inputBuffers[])
{
	float inputColor1[4];
	float inputColor2[4];
	float value;
	
	inputValueOperation->read(&value, x, y, sampler, inputBuffers);
	inputColor1Operation->read(&inputColor1[0], x, y, sampler, inputBuffers);
	inputColor2Operation->read(&inputColor2[0], x, y, sampler, inputBuffers);
	
	if (this->useValueAlphaMultiply()) {
		value *= inputColor2[3];
	}
	
	float valuem = 1.0f - value;
	
	if (inputColor1[0] < 0.5f) {
		outputValue[0] = inputColor1[0] * (valuem + 2.0f * value * inputColor2[0]);
	}
	else {
		outputValue[0] = 1.0f - (valuem + 2.0f * value * (1.0f - inputColor2[0])) * (1.0f - inputColor1[0]);
	}
	if (inputColor1[1] < 0.5f) {
		outputValue[1] = inputColor1[1] * (valuem + 2.0f * value * inputColor2[1]);
	}
	else {
		outputValue[1] = 1.0f - (valuem + 2.0f * value * (1.0f - inputColor2[1])) * (1.0f - inputColor1[1]);
	}
	if (inputColor1[2] < 0.5f) {
		outputValue[2] = inputColor1[2] * (valuem + 2.0f * value * inputColor2[2]);
	}
	else {
		outputValue[2] = 1.0f - (valuem + 2.0f * value * (1.0f - inputColor2[2])) * (1.0f - inputColor1[2]);
	}
	outputValue[3] = inputColor1[3];
}