/*
 * 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_ProjectorLensDistortionOperation.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"

namespace blender::compositor {

ProjectorLensDistortionOperation::ProjectorLensDistortionOperation()
{
  this->addInputSocket(DataType::Color);
  this->addInputSocket(DataType::Value);
  this->addOutputSocket(DataType::Color);
  this->flags.complex = true;
  this->m_inputProgram = nullptr;
  this->m_dispersionAvailable = false;
  this->m_dispersion = 0.0f;
}
void ProjectorLensDistortionOperation::initExecution()
{
  this->initMutex();
  this->m_inputProgram = this->getInputSocketReader(0);
}

void *ProjectorLensDistortionOperation::initializeTileData(rcti * /*rect*/)
{
  updateDispersion();
  void *buffer = this->m_inputProgram->initializeTileData(nullptr);
  return buffer;
}

void ProjectorLensDistortionOperation::executePixel(float output[4], int x, int y, void *data)
{
  float inputValue[4];
  const float height = this->getHeight();
  const float width = this->getWidth();
  const float v = (y + 0.5f) / height;
  const float u = (x + 0.5f) / width;
  MemoryBuffer *inputBuffer = (MemoryBuffer *)data;
  inputBuffer->readBilinear(inputValue, (u * width + this->m_kr2) - 0.5f, v * height - 0.5f);
  output[0] = inputValue[0];
  inputBuffer->read(inputValue, x, y);
  output[1] = inputValue[1];
  inputBuffer->readBilinear(inputValue, (u * width - this->m_kr2) - 0.5f, v * height - 0.5f);
  output[2] = inputValue[2];
  output[3] = 1.0f;
}

void ProjectorLensDistortionOperation::deinitExecution()
{
  this->deinitMutex();
  this->m_inputProgram = nullptr;
}

bool ProjectorLensDistortionOperation::determineDependingAreaOfInterest(
    rcti *input, ReadBufferOperation *readOperation, rcti *output)
{
  rcti newInput;
  if (this->m_dispersionAvailable) {
    newInput.ymax = input->ymax;
    newInput.ymin = input->ymin;
    newInput.xmin = input->xmin - this->m_kr2 - 2;
    newInput.xmax = input->xmax + this->m_kr2 + 2;
  }
  else {
    rcti dispInput;
    BLI_rcti_init(&dispInput, 0, 5, 0, 5);
    if (this->getInputOperation(1)->determineDependingAreaOfInterest(
            &dispInput, readOperation, output)) {
      return true;
    }
    newInput.xmin = input->xmin - 7; /* (0.25f * 20 * 1) + 2 == worse case dispersion */
    newInput.ymin = input->ymin;
    newInput.ymax = input->ymax;
    newInput.xmax = input->xmax + 7; /* (0.25f * 20 * 1) + 2 == worse case dispersion */
  }
  if (this->getInputOperation(0)->determineDependingAreaOfInterest(
          &newInput, readOperation, output)) {
    return true;
  }
  return false;
}

void ProjectorLensDistortionOperation::updateDispersion()
{
  if (this->m_dispersionAvailable) {
    return;
  }
  this->lockMutex();
  if (!this->m_dispersionAvailable) {
    float result[4];
    this->getInputSocketReader(1)->readSampled(result, 1, 1, PixelSampler::Nearest);
    this->m_dispersion = result[0];
    this->m_kr = 0.25f * max_ff(min_ff(this->m_dispersion, 1.0f), 0.0f);
    this->m_kr2 = this->m_kr * 20;
    this->m_dispersionAvailable = true;
  }
  this->unlockMutex();
}

}  // namespace blender::compositor
