/*
 * 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.
 *
 * Copyright 2011, Blender Foundation.
 */

#include "COM_ColorMatteOperation.h"
#include "BLI_math.h"

ColorMatteOperation::ColorMatteOperation() : NodeOperation()
{
  addInputSocket(COM_DT_COLOR);
  addInputSocket(COM_DT_COLOR);
  addOutputSocket(COM_DT_VALUE);

  this->m_inputImageProgram = NULL;
  this->m_inputKeyProgram = NULL;
}

void ColorMatteOperation::initExecution()
{
  this->m_inputImageProgram = this->getInputSocketReader(0);
  this->m_inputKeyProgram = this->getInputSocketReader(1);
}

void ColorMatteOperation::deinitExecution()
{
  this->m_inputImageProgram = NULL;
  this->m_inputKeyProgram = NULL;
}

void ColorMatteOperation::executePixelSampled(float output[4],
                                              float x,
                                              float y,
                                              PixelSampler sampler)
{
  float inColor[4];
  float inKey[4];

  const float hue = this->m_settings->t1;
  const float sat = this->m_settings->t2;
  const float val = this->m_settings->t3;

  float h_wrap;

  this->m_inputImageProgram->readSampled(inColor, x, y, sampler);
  this->m_inputKeyProgram->readSampled(inKey, x, y, sampler);

  /* store matte(alpha) value in [0] to go with
   * COM_SetAlphaOperation and the Value output
   */

  if (
      /* do hue last because it needs to wrap, and does some more checks  */

      /* sat */ (fabsf(inColor[1] - inKey[1]) < sat) &&
      /* val */ (fabsf(inColor[2] - inKey[2]) < val) &&

      /* multiply by 2 because it wraps on both sides of the hue,
       * otherwise 0.5 would key all hue's */

      /* hue */ ((h_wrap = 2.0f * fabsf(inColor[0] - inKey[0])) < hue || (2.0f - h_wrap) < hue)) {
    output[0] = 0.0f; /* make transparent */
  }

  else {                    /*pixel is outside key color */
    output[0] = inColor[3]; /* make pixel just as transparent as it was before */
  }
}
