/*
 * 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_ViewerOperation.h"
#include "BLI_listbase.h"
#include "BKE_image.h"
#include "BKE_scene.h"
#include "WM_api.h"
#include "WM_types.h"
#include "PIL_time.h"
#include "BLI_utildefines.h"
#include "BLI_math_color.h"
#include "BLI_math_vector.h"

extern "C" {
#include "MEM_guardedalloc.h"
#include "IMB_imbuf.h"
#include "IMB_imbuf_types.h"
#include "IMB_colormanagement.h"
}

ViewerOperation::ViewerOperation() : NodeOperation()
{
  this->setImage(NULL);
  this->setImageUser(NULL);
  this->m_outputBuffer = NULL;
  this->m_depthBuffer = NULL;
  this->m_active = false;
  this->m_doDepthBuffer = false;
  this->m_viewSettings = NULL;
  this->m_displaySettings = NULL;
  this->m_useAlphaInput = false;

  this->addInputSocket(COM_DT_COLOR);
  this->addInputSocket(COM_DT_VALUE);
  this->addInputSocket(COM_DT_VALUE);

  this->m_imageInput = NULL;
  this->m_alphaInput = NULL;
  this->m_depthInput = NULL;
  this->m_rd = NULL;
  this->m_viewName = NULL;
}

void ViewerOperation::initExecution()
{
  // When initializing the tree during initial load the width and height can be zero.
  this->m_imageInput = getInputSocketReader(0);
  this->m_alphaInput = getInputSocketReader(1);
  this->m_depthInput = getInputSocketReader(2);
  this->m_doDepthBuffer = (this->m_depthInput != NULL);

  if (isActiveViewerOutput()) {
    initImage();
  }
}

void ViewerOperation::deinitExecution()
{
  this->m_imageInput = NULL;
  this->m_alphaInput = NULL;
  this->m_depthInput = NULL;
  this->m_outputBuffer = NULL;
}

void ViewerOperation::executeRegion(rcti *rect, unsigned int /*tileNumber*/)
{
  float *buffer = this->m_outputBuffer;
  float *depthbuffer = this->m_depthBuffer;
  if (!buffer) {
    return;
  }
  const int x1 = rect->xmin;
  const int y1 = rect->ymin;
  const int x2 = rect->xmax;
  const int y2 = rect->ymax;
  const int offsetadd = (this->getWidth() - (x2 - x1));
  const int offsetadd4 = offsetadd * 4;
  int offset = (y1 * this->getWidth() + x1);
  int offset4 = offset * 4;
  float alpha[4], depth[4];
  int x;
  int y;
  bool breaked = false;

  for (y = y1; y < y2 && (!breaked); y++) {
    for (x = x1; x < x2; x++) {
      this->m_imageInput->readSampled(&(buffer[offset4]), x, y, COM_PS_NEAREST);
      if (this->m_useAlphaInput) {
        this->m_alphaInput->readSampled(alpha, x, y, COM_PS_NEAREST);
        buffer[offset4 + 3] = alpha[0];
      }
      this->m_depthInput->readSampled(depth, x, y, COM_PS_NEAREST);
      depthbuffer[offset] = depth[0];

      offset++;
      offset4 += 4;
    }
    if (isBreaked()) {
      breaked = true;
    }
    offset += offsetadd;
    offset4 += offsetadd4;
  }
  updateImage(rect);
}

void ViewerOperation::initImage()
{
  Image *ima = this->m_image;
  ImageUser iuser = *this->m_imageUser;
  void *lock;
  ImBuf *ibuf;

  /* make sure the image has the correct number of views */
  if (ima && BKE_scene_multiview_is_render_view_first(this->m_rd, this->m_viewName)) {
    BKE_image_verify_viewer_views(this->m_rd, ima, this->m_imageUser);
  }

  BLI_thread_lock(LOCK_DRAW_IMAGE);

  /* local changes to the original ImageUser */
  iuser.multi_index = BKE_scene_multiview_view_id_get(this->m_rd, this->m_viewName);
  ibuf = BKE_image_acquire_ibuf(ima, &iuser, &lock);

  if (!ibuf) {
    BLI_thread_unlock(LOCK_DRAW_IMAGE);
    return;
  }
  if (ibuf->x != (int)getWidth() || ibuf->y != (int)getHeight()) {

    imb_freerectImBuf(ibuf);
    imb_freerectfloatImBuf(ibuf);
    IMB_freezbuffloatImBuf(ibuf);
    ibuf->x = getWidth();
    ibuf->y = getHeight();
    /* zero size can happen if no image buffers exist to define a sensible resolution */
    if (ibuf->x > 0 && ibuf->y > 0) {
      imb_addrectfloatImBuf(ibuf);
    }
    ima->ok = IMA_OK_LOADED;

    ibuf->userflags |= IB_DISPLAY_BUFFER_INVALID;
  }

  if (m_doDepthBuffer) {
    addzbuffloatImBuf(ibuf);
  }

  /* now we combine the input with ibuf */
  this->m_outputBuffer = ibuf->rect_float;

  /* needed for display buffer update */
  this->m_ibuf = ibuf;

  if (m_doDepthBuffer) {
    this->m_depthBuffer = ibuf->zbuf_float;
  }

  BKE_image_release_ibuf(this->m_image, this->m_ibuf, lock);

  BLI_thread_unlock(LOCK_DRAW_IMAGE);
}

void ViewerOperation::updateImage(rcti *rect)
{
  IMB_partial_display_buffer_update(this->m_ibuf,
                                    this->m_outputBuffer,
                                    NULL,
                                    getWidth(),
                                    0,
                                    0,
                                    this->m_viewSettings,
                                    this->m_displaySettings,
                                    rect->xmin,
                                    rect->ymin,
                                    rect->xmax,
                                    rect->ymax);

  this->updateDraw();
}

CompositorPriority ViewerOperation::getRenderPriority() const
{
  if (this->isActiveViewerOutput()) {
    return COM_PRIORITY_HIGH;
  }
  else {
    return COM_PRIORITY_LOW;
  }
}
