text: /*
   * 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_CalculateMeanOperation.h"
  #include "BLI_math.h"
  #include "BLI_utildefines.h"
  
  extern "C" {
  #include "IMB_colormanagement.h"
  }
  
  CalculateMeanOperation::CalculateMeanOperation() : NodeOperation()
  {
  	this->addInputSocket(COM_DT_COLOR, COM_SC_NO_RESIZE);
  	this->addOutputSocket(COM_DT_VALUE);
  	this->m_imageReader = NULL;
  	this->m_iscalculated = false;
  	this->m_setting = 1;
  	this->setComplex(true);
  }
  void CalculateMeanOperation::initExecution()
  {
  	this->m_imageReader = this->getInputSocketReader(0);
  	this->m_iscalculated = false;
  	NodeOperation::initMutex();
  }
  
  void CalculateMeanOperation::executePixel(float output[4],
                                            int /*x*/, int /*y*/,
                                            void * /*data*/)
  {
  	output[0] = this->m_result;
  }
  
  void CalculateMeanOperation::deinitExecution()
  {
  	this->m_imageReader = NULL;
  	NodeOperation::deinitMutex();
  }
  
  bool CalculateMeanOperation::determineDependingAreaOfInterest(rcti * /*input*/, ReadBufferOperation *readOperation, rcti *output)
  {
  	rcti imageInput;
  	if (this->m_iscalculated) {
  		return false;
  	}
  	NodeOperation *operation = getInputOperation(0);
  	imageInput.xmax = operation->getWidth();
  	imageInput.xmin = 0;
  	imageInput.ymax = operation->getHeight();
  	imageInput.ymin = 0;
  	if (operation->determineDependingAreaOfInterest(&imageInput, readOperation, output) ) {
  		return true;
  	}
  	return false;
  }
  
  void *CalculateMeanOperation::initializeTileData(rcti *rect)
  {
  	lockMutex();
  	if (!this->m_iscalculated) {
  		MemoryBuffer *tile = (MemoryBuffer *)this->m_imageReader->initializeTileData(rect);
  		calculateMean(tile);
  		this->m_iscalculated = true;
  	}
  	unlockMutex();
  	return NULL;
  }
  
  void CalculateMeanOperation::calculateMean(MemoryBuffer *tile)
  {
  	this->m_result = 0.0f;
  	float *buffer = tile->getBuffer();
  	int size = tile->getWidth() * tile->getHeight();
  	int pixels = 0;
  	float sum = 0.0f;
  	for (int i = 0, offset = 0; i < size; i++, offset += 4) {
  		if (buffer[offset + 3] > 0) {
  			pixels++;
  	
  			switch (this->m_setting) {
  				case 1:
  				{
  					sum += IMB_colormanagement_get_luminance(&buffer[offset]);
  					break;
  				}
  				case 2:
  				{
  					sum += buffer[offset];
  					break;
  				}
  				case 3:
  				{
  					sum += buffer[offset + 1];
  					break;
  				}
  				case 4:
  				{
  					sum += buffer[offset + 2];
  					break;
  				}
  				case 5:
  				{
  					float yuv[3];
  					rgb_to_yuv(buffer[offset], buffer[offset + 1], buffer[offset + 2], &yuv[0], &yuv[1], &yuv[2]);
  					sum += yuv[0];
  					break;
  				}
  			}
  		}
  	}
  	this->m_result = sum / pixels;
  }
  