/*=========================================================================

  Program:   ParaView
  Module:    $RCSfile$

  Copyright (c) Kitware, Inc.
  All rights reserved.
  See Copyright.txt or http://www.paraview.org/HTML/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkIceTCompositePass.h"

#include "vtkBoundingBox.h"
#include "vtkCubeAxesActor.h"
#include "vtkFloatArray.h"
#include "vtkFrameBufferObject.h"
#include "vtkIceTContext.h"
#include "vtkIntArray.h"
#include "vtkMultiProcessController.h"
#include "vtkObjectFactory.h"
#include "vtkPKdTree.h"
#include "vtkPixelBufferObject.h"
#include "vtkRenderState.h"
#include "vtkRenderWindow.h"
#include "vtkOpenGLRenderWindow.h"
#include "vtkRenderer.h"
#include "vtkSmartPointer.h"
#include "vtkTextureObject.h"
#include "vtkTilesHelper.h"
#include "vtkOpenGLError.h"

#include <assert.h>
#include "vtk_icet.h"

#ifdef VTKGL2
# include "vtkMatrix3x3.h"
# include "vtkMatrix4x4.h"
# include "vtkOpenGLCamera.h"
# include "vtkOpenGLShaderCache.h"
# include "vtkShaderProgram.h"
# include "vtkglVBOHelper.h"
# include "vtkTextureObjectVS.h"
# include "vtkCompositeZPassFS.h"
#else
# include "vtkCamera.h"
# include "vtkgl.h"
# include "vtkShader2.h"
# include "vtkShader2Collection.h"
# include "vtkShaderProgram2.h"
# include "vtkTextureUnitManager.h"
# include "vtkUniformVariables.h"
extern const char *vtkIceTCompositeZPassShader_fs;
#endif


namespace
{
  static vtkIceTCompositePass* IceTDrawCallbackHandle = NULL;
  static const vtkRenderState* IceTDrawCallbackState = NULL;
  void IceTDrawCallback()
    {
    if (IceTDrawCallbackState && IceTDrawCallbackHandle)
      {
      IceTDrawCallbackHandle->Draw(IceTDrawCallbackState);
      }
    }

  void MergeCubeAxesBounds(double bounds[6], const vtkRenderState* rState)
    {
    vtkBoundingBox bbox(bounds);

    // Hande CubeAxes specifically has it wrongly implement the GetBounds()
    for (int cc=0; cc < rState->GetPropArrayCount(); cc++)
      {
      vtkProp* prop = rState->GetPropArray()[cc];
      vtkCubeAxesActor* cubeAxes = vtkCubeAxesActor::SafeDownCast(prop);
      if (cubeAxes != NULL && prop->GetVisibility() &&
        prop->GetUseBounds())
        {
        // Use custom bounds API for cube axes to embed titles and labels
        bbox.AddBounds(cubeAxes->GetRenderedBounds());
        }
      }

    bbox.GetBounds(bounds);
    }
};

vtkStandardNewMacro(vtkIceTCompositePass);
vtkCxxSetObjectMacro(vtkIceTCompositePass, RenderPass, vtkRenderPass);
vtkCxxSetObjectMacro(vtkIceTCompositePass, KdTree, vtkPKdTree);
vtkCxxSetObjectMacro(vtkIceTCompositePass, Controller,
  vtkMultiProcessController);
//----------------------------------------------------------------------------
vtkIceTCompositePass::vtkIceTCompositePass()
  : LastRenderedDepths()
{
  this->IceTContext = vtkIceTContext::New();
  this->IceTContext->UseOpenGLOn();
  this->Controller = 0;
  this->RenderPass = 0;
  this->KdTree = 0;
  this->TileMullions[0] = this->TileMullions[1] = 0;
  this->TileDimensions[0] = 1;
  this->TileDimensions[1] = 1;

  this->LastTileDimensions[0] = this->LastTileDimensions[1] = -1;
  this->LastTileMullions[0] = this->LastTileMullions[1] = -1;
  this->LastTileViewport[0] = this->LastTileViewport[1] =
    this->LastTileViewport[2] = this->LastTileViewport[3] = 0;

  this->DataReplicatedOnAllProcesses = false;
  this->ImageReductionFactor = 1;

  this->RenderEmptyImages = false;
  this->UseOrderedCompositing = false;
  this->DepthOnly=false;

  this->LastRenderedEyes[0] = new vtkSynchronizedRenderers::vtkRawImage();
  this->LastRenderedEyes[1] = new vtkSynchronizedRenderers::vtkRawImage();
  this->LastRenderedRGBAColors = this->LastRenderedEyes[0];

  this->PBO=0;
  this->ZTexture=0;
  this->Program=0;
  this->FixBackground=false;
  this->BackgroundTexture=0;
  this->IceTTexture=0;
}

//----------------------------------------------------------------------------
vtkIceTCompositePass::~vtkIceTCompositePass()
{
  if(this->PBO!=0)
    {
    vtkErrorMacro(<<"PixelBufferObject should have been deleted in ReleaseGraphicsResources().");
    }
  if(this->ZTexture!=0)
    {
    vtkErrorMacro(<<"ZTexture should have been deleted in ReleaseGraphicsResources().");
    }
  if(this->Program!=0)
    {
#ifdef VTKGL2
     delete this->Program;
#else
     this->Program->Delete();
#endif
    this->Program = 0;
    }

  this->SetKdTree(0);
  this->SetRenderPass(0);
  this->SetController(0);
  this->IceTContext->Delete();
  this->IceTContext = 0;

  delete this->LastRenderedEyes[0];
  delete this->LastRenderedEyes[1];
  this->LastRenderedEyes[0] = NULL;
  this->LastRenderedEyes[1] = NULL;
  this->LastRenderedRGBAColors = NULL;

  if(this->BackgroundTexture!=0)
    {
    vtkErrorMacro(<<"BackgroundTexture should have been deleted in ReleaseGraphicsResources().");
    }
  if(this->IceTTexture!=0)
    {
    vtkErrorMacro(<<"IceTTexture should have been deleted in ReleaseGraphicsResources().");
    }
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::ReleaseGraphicsResources(vtkWindow* window)
{
  if(this->RenderPass!=0)
    {
    this->RenderPass->ReleaseGraphicsResources(window);
    }

  if(this->PBO!=0)
    {
    this->PBO->Delete();
    this->PBO=0;
    }
  if(this->ZTexture!=0)
    {
    this->ZTexture->Delete();
    this->ZTexture=0;
    }
  if(this->Program!=0)
    {
#ifdef VTKGL2
    this->Program->ReleaseGraphicsResources(window);
#else
    this->Program->ReleaseGraphicsResources();
#endif
    }
  if(this->BackgroundTexture!=0)
    {
    this->BackgroundTexture->Delete();
    this->BackgroundTexture=0;
    }
  if(this->IceTTexture!=0)
    {
    this->IceTTexture->Delete();
    this->IceTTexture=0;
    }
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::SetupContext(const vtkRenderState* render_state)
{
  vtkOpenGLClearErrorMacro();

  //icetDiagnostics(ICET_DIAG_DEBUG | ICET_DIAG_ALL_NODES);

#ifdef VTKGL2
  vtkOpenGLCamera *cam = vtkOpenGLCamera::SafeDownCast(render_state->GetRenderer()->GetActiveCamera());
  vtkMatrix4x4 *wcvc;
  vtkMatrix3x3 *norms;
  vtkMatrix4x4 *vcdc;
  vtkMatrix4x4 *unused;
  cam->GetKeyMatrices(render_state->GetRenderer(), wcvc, norms, vcdc, unused);
  glMatrixMode(GL_PROJECTION);
  glLoadMatrixd(vcdc->Element[0]);
  glMatrixMode(GL_MODELVIEW);
  glLoadMatrixd(wcvc->Element[0]);
#endif

  // Irrespective of whether we are rendering in tile/display mode or not, we
  // need to pass appropriate tile parameters to IceT.
  this->UpdateTileInformation(render_state);

  // Set IceT compositing strategy.
  if ((this->TileDimensions[0] == 1) && (this->TileDimensions[1] == 1))
    {
    icetStrategy(ICET_STRATEGY_SEQUENTIAL);
    }
  else
    {
    icetStrategy(ICET_STRATEGY_REDUCE);
    }

  bool use_ordered_compositing =
    (this->KdTree && this->UseOrderedCompositing && !this->DepthOnly &&
     this->KdTree->GetNumberOfRegions() >=
     this->IceTContext->GetController()->GetNumberOfProcesses());

  if(this->DepthOnly)
    {
    icetSetColorFormat(ICET_IMAGE_COLOR_NONE);
    icetSetDepthFormat(ICET_IMAGE_DEPTH_FLOAT);
    icetCompositeMode(ICET_COMPOSITE_MODE_Z_BUFFER);
    }
  else
    {
    // If translucent geometry is present, then we should not include
    // ICET_DEPTH_BUFFER_BIT in  the input-buffer argument.
    if (use_ordered_compositing)
      {
      icetSetColorFormat(ICET_IMAGE_COLOR_RGBA_UBYTE);
      icetSetDepthFormat(ICET_IMAGE_DEPTH_NONE);
      icetCompositeMode(ICET_COMPOSITE_MODE_BLEND);
      }
    else
      {
      icetSetColorFormat(ICET_IMAGE_COLOR_RGBA_UBYTE);
      icetSetDepthFormat(ICET_IMAGE_DEPTH_FLOAT);
      icetDisable(ICET_COMPOSITE_ONE_BUFFER);
      icetCompositeMode(ICET_COMPOSITE_MODE_Z_BUFFER);
      }
    }

  icetEnable(ICET_FLOATING_VIEWPORT);
  if (use_ordered_compositing)
    {
    // if ordered compositing is enabled, pass the process order from the kdtree
    // to icet.

    // Setup IceT context for correct sorting.
    icetEnable(ICET_ORDERED_COMPOSITE);

    // Order all the regions.
    vtkIntArray *orderedProcessIds = vtkIntArray::New();
    vtkCamera *camera = render_state->GetRenderer()->GetActiveCamera();
    if (camera->GetParallelProjection())
      {
      this->KdTree->ViewOrderAllProcessesInDirection(
        camera->GetDirectionOfProjection(),
        orderedProcessIds);
      }
    else
      {
      this->KdTree->ViewOrderAllProcessesFromPosition(
        camera->GetPosition(), orderedProcessIds);
      }

    if (sizeof(int) == sizeof(IceTInt))
      {
      icetCompositeOrder((IceTInt *)orderedProcessIds->GetPointer(0));
      }
    else
      {
      vtkIdType numprocs = orderedProcessIds->GetNumberOfTuples();
      IceTInt *tmparray = new IceTInt[numprocs];
      const int *opiarray = orderedProcessIds->GetPointer(0);
      std::copy(opiarray, opiarray+numprocs, tmparray);
      icetCompositeOrder(tmparray);
      delete[] tmparray;
      }
    orderedProcessIds->Delete();
    }
  else
    {
    icetDisable(ICET_ORDERED_COMPOSITE);
    }

  // Let IceT know the data bounds. This allows IceT to make smarter compositing
  // decisions.
  double allBounds[6];
  render_state->GetRenderer()->ComputeVisiblePropBounds(allBounds);

  //Try to detect when bounds are empty and try to let IceT know that
  //nothing is in bounds.
  if (allBounds[0] > allBounds[1])
    {
    vtkDebugMacro("nothing visible" << endl);
    IceTFloat tmp = VTK_FLOAT_MAX;
    icetBoundingVertices(1, ICET_FLOAT, 0, 1, &tmp);
    }
  else
    {
    // ComputeVisiblePropBounds() includes bounds from all props, however it
    // cannot include the "real" bounds from vtkCubeAxesActor. Thanks to
    // vtkCubeAxesActor overriding the 'GetBounds' method to return the inner
    // bounds rather that the prop  bounds for the actor. That results in BUG#
    // 13469. Hence, to overcome that issue, we iterate over the props to locate
    // vtkCubeAxesActor and include the outer bounds.
    MergeCubeAxesBounds(allBounds, render_state);

    icetBoundingBoxd(allBounds[0], allBounds[1], allBounds[2], allBounds[3],
                     allBounds[4], allBounds[5]);
    }

  // Let IceT do the pasting composited image to screen when it can do so
  // correctly.
  if (!this->FixBackground && !this->DepthOnly)
    {
    icetEnable(ICET_GL_DISPLAY);
    icetEnable(ICET_GL_DISPLAY_INFLATE);
    }
  else
    {
    // we'll push the icet composited-buffer to screen at the end.
    icetDisable(ICET_GL_DISPLAY);
    icetDisable(ICET_GL_DISPLAY_INFLATE);
    }

  if (this->DataReplicatedOnAllProcesses)
    {
    icetDataReplicationGroupColor(1);
    }
  else
    {
    icetDataReplicationGroupColor(
      static_cast<IceTInt>(this->Controller->GetLocalProcessId()));
    }

  // capture color buffer
  if (this->FixBackground)
    {
    // This can  be optimized. This is currently capturing the whole render
    // window, we only need to capture the part covered by this renderer.
    int tile_size[2];
    if (render_state->GetFrameBuffer())
      {
      render_state->GetFrameBuffer()->GetLastSize(tile_size);
      }
    else
      {
      vtkWindow* window = render_state->GetRenderer()->GetVTKWindow();
      // NOTE: GetActualSize() does not include the TileScale.
      tile_size[0] = window->GetActualSize()[0];
      tile_size[1] = window->GetActualSize()[1];
      }

    vtkOpenGLRenderWindow *context=
      static_cast<vtkOpenGLRenderWindow *>(
        render_state->GetRenderer()->GetRenderWindow());

    if (this->BackgroundTexture==0)
      {
      this->BackgroundTexture=vtkTextureObject::New();
      this->BackgroundTexture->SetContext(context);
      }
    // only get RGB, this is the background so we ignore A.
    this->BackgroundTexture->Allocate2D(tile_size[0], tile_size[1], 3,
      VTK_UNSIGNED_CHAR);
    this->BackgroundTexture->CopyFromFrameBuffer(0, 0, 0, 0,
      tile_size[0], tile_size[1]);
    }

  // IceT will use the full render window.  We'll move images back where they
  // belong later.
  //int *size = render_state->GetRenderer()->GetVTKWindow()->GetActualSize();
  //glViewport(0, 0, size[0], size[1]);
  //glDisable(GL_SCISSOR_TEST);
  GLbitfield clear_mask = 0;
  if (!render_state->GetRenderer()->Transparent())
    {
    glClearColor((GLclampf)(0.0), (GLclampf)(0.0),
      (GLclampf)(0.0), (GLclampf)(0.0));
    clear_mask |= GL_COLOR_BUFFER_BIT;
    }
  if (!render_state->GetRenderer()->GetPreserveDepthBuffer())
    {
    glClearDepth(static_cast<GLclampf>(1.0));
    clear_mask |= GL_DEPTH_BUFFER_BIT;
    }
  glClear(clear_mask);
  //icetEnable(ICET_CORRECT_COLORED_BACKGROUND);

  // when a painter needs to use MPI global collective
  // communications the empty images option ensures
  // that all painters including those without visible data
  // are executed
  if (this->RenderEmptyImages)
    {
    icetEnable(ICET_RENDER_EMPTY_IMAGES);
    }
  else
    {
    icetDisable(ICET_RENDER_EMPTY_IMAGES);
    }

  vtkOpenGLCheckErrorMacro("failed after SetupContext");
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::CleanupContext(const vtkRenderState*)
{
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::Render(const vtkRenderState* render_state)
{
  this->IceTContext->SetController(this->Controller);
  if (!this->IceTContext->IsValid())
    {
    vtkErrorMacro("Could not initialize IceT context.");
    return;
    }

  this->IceTContext->MakeCurrent();
  this->SetupContext(render_state);

  icetGLDrawCallback(IceTDrawCallback);
  IceTDrawCallbackHandle = this;
  IceTDrawCallbackState = render_state;
  IceTImage renderedImage = icetGLDrawFrame();
  IceTDrawCallbackHandle = NULL;
  IceTDrawCallbackState = NULL;

  // isolate vtk from IceT OpenGL errors
  vtkOpenGLClearErrorMacro();

  if (render_state->GetRenderer()->GetRenderWindow()->GetStereoRender() == 1)
    {
    //if we are doing a stereo render we need to know
    //which stereo eye we are currently rendering. If we don't do this
    //we will overwrite the left eye with the right eye image
    int eyeIndex =
      render_state->GetRenderer()->GetActiveCamera()->GetLeftEye() == 1 ? 0 : 1;
    this->LastRenderedRGBAColors = this->LastRenderedEyes[eyeIndex];
    }

  // Capture image.
  vtkIdType numPixels = icetImageGetNumPixels(renderedImage);
  if (icetImageGetColorFormat(renderedImage) != ICET_IMAGE_COLOR_NONE)
    {
    this->LastRenderedRGBAColors->Resize(icetImageGetWidth(renderedImage),
      icetImageGetHeight(renderedImage), 4);
    icetImageCopyColorub(renderedImage,
      this->LastRenderedRGBAColors->GetRawPtr()->GetPointer(0),
      ICET_IMAGE_COLOR_RGBA_UBYTE);
    this->LastRenderedRGBAColors->MarkValid();
    }
  else
    {
    this->LastRenderedRGBAColors->MarkInValid();
    }
  if (icetImageGetDepthFormat(renderedImage) != ICET_IMAGE_DEPTH_NONE)
    {
    this->LastRenderedDepths->SetNumberOfComponents(1);
    this->LastRenderedDepths->SetNumberOfTuples(numPixels);
    icetImageCopyDepthf(renderedImage,
                        this->LastRenderedDepths->GetPointer(0),
                        ICET_IMAGE_DEPTH_FLOAT);
    }
  else
    {
    this->LastRenderedDepths->SetNumberOfTuples(0);
    }

  if(this->DepthOnly)
    {
    this->PushIceTDepthBufferToScreen(render_state);
    }
  else if (this->FixBackground)
    {
    this->PushIceTColorBufferToScreen(render_state);
    }

  this->CleanupContext(render_state);
}

// ----------------------------------------------------------------------------
void vtkIceTCompositePass::CreateProgram(vtkOpenGLRenderWindow *context)
{
  assert("pre: context_exists" && context!=0);
  assert("pre: Program_void" && this->Program==0);

#ifdef VTKGL2
  this->Program = new vtkgl::CellBO;
  this->Program->Program =
    context->GetShaderCache()->ReadyShader(vtkTextureObjectVS,
                                           vtkCompositeZPassFS,
                                           "");
  if (!this->Program->Program)
    {
    vtkErrorMacro("Shader program failed to build.");
    }
#else
  this->Program=vtkShaderProgram2::New();
  this->Program->SetContext(context);

  vtkShader2 *shader=vtkShader2::New();
  shader->SetContext(context);

  this->Program->GetShaders()->AddItem(shader);
  shader->Delete();
  shader->SetType(VTK_SHADER_TYPE_FRAGMENT);
  shader->SetSourceCode(vtkIceTCompositeZPassShader_fs);
  this->Program->Build();
  if(this->Program->GetLastBuildStatus()!=VTK_SHADER_PROGRAM2_LINK_SUCCEEDED)
    {
    vtkErrorMacro("prog build failed");
    }
#endif

  assert("post: Program_exists" && this->Program!=0);
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::Draw(const vtkRenderState* render_state)
{
  vtkOpenGLClearErrorMacro();

  GLbitfield clear_mask = 0;
  if (!this->DepthOnly)
    {
    if (!render_state->GetRenderer()->Transparent())
      {
      clear_mask |= GL_COLOR_BUFFER_BIT;
      }
    if (!render_state->GetRenderer()->GetPreserveDepthBuffer())
      {
      clear_mask |= GL_DEPTH_BUFFER_BIT;
      }
    }
  else
    {
    if (!render_state->GetRenderer()->GetPreserveDepthBuffer())
      {
      clear_mask |= GL_DEPTH_BUFFER_BIT;
      }
    glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
    }
  glClear(clear_mask);
  if (this->RenderPass)
    {
#ifdef VTKGL2
    // IceT messes with the old fixed pipeline matrices
    // so we need to get the updated ones and pass them
    // on to thecamera for use

    vtkOpenGLCamera *cam = vtkOpenGLCamera::SafeDownCast(render_state->GetRenderer()->GetActiveCamera());
    vtkMatrix4x4 *wcvc;
    vtkMatrix3x3 *norms;
    vtkMatrix4x4 *vcdc;
    vtkMatrix4x4 *unused;
    cam->GetKeyMatrices(render_state->GetRenderer(), wcvc, norms, vcdc, unused);
    // double projection_matrix[16];
    // double modelview_matrix[16];
    glGetDoublev(GL_PROJECTION_MATRIX, vcdc->Element[0]);
    glGetDoublev(GL_MODELVIEW_MATRIX, wcvc->Element[0]);
    this->RenderPass->Render(render_state);
    cam->Modified();
#else
    this->RenderPass->Render(render_state);
#endif
    }
  if(this->DepthOnly)
    {
    glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);
    }

  vtkOpenGLCheckErrorMacro("failed after Draw");
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::UpdateTileInformation(
  const vtkRenderState* render_state)
{
  double image_reduction_factor = this->ImageReductionFactor > 0?
    this->ImageReductionFactor : 1.0;

  int actual_size[2];
  int tile_size[2];
  int tile_mullions[2];
  this->GetTileMullions(tile_mullions);

  // NOTE: GetActualSize() does not include the TileScale.
  vtkWindow* window = render_state->GetRenderer()->GetVTKWindow();
  actual_size[0] = window->GetActualSize()[0];
  actual_size[1] = window->GetActualSize()[1];


  double viewport[4] = {0, 0, 1, 1};
  if (render_state->GetFrameBuffer())
    {
    // When  frame buffer is present, we assume that this pass is used as a
    // delegate to some image-processing like pass. In which case the processing
    // pass maybe needing some extra padding of pixels. We compute an estimate
    // of those extra pixels by comparing with the actual window size.
    render_state->GetFrameBuffer()->GetLastSize(tile_size);
    tile_mullions[0] -= (tile_size[0] - actual_size[0]);
    tile_mullions[1] -= (tile_size[1] - actual_size[1]);
    }
  else
    {
    tile_size[0] = actual_size[0];
    tile_size[1] = actual_size[1];
    render_state->GetRenderer()->GetViewport(viewport);
    }

  vtkSmartPointer<vtkTilesHelper> tilesHelper = vtkSmartPointer<vtkTilesHelper>::New();
  tilesHelper->SetTileDimensions(this->TileDimensions);
  tilesHelper->SetTileMullions(tile_mullions);
  tilesHelper->SetTileWindowSize(tile_size);

  int rank = this->Controller->GetLocalProcessId();
  int my_tile_viewport[4];
  if (tilesHelper->GetTileViewport(viewport, rank, my_tile_viewport))
    {
    // LastTileViewport is the icet viewport for the current renderer (treating
    // all tiles as one large display).
    this->LastTileViewport[0] = static_cast<int>(
      my_tile_viewport[0]/image_reduction_factor);
    this->LastTileViewport[1] = static_cast<int>(
      my_tile_viewport[1]/image_reduction_factor);
    this->LastTileViewport[2] = static_cast<int>(
      my_tile_viewport[2]/image_reduction_factor);
    this->LastTileViewport[3] = static_cast<int>(
      my_tile_viewport[3]/image_reduction_factor);


    // PhysicalViewport is the viewport in the current render-window where the
    // renderer maps.
    if (render_state->GetFrameBuffer())
      {
      double physical_viewport[4];
      render_state->GetRenderer()->GetViewport(physical_viewport);
      tilesHelper->SetTileMullions(this->TileMullions);
      tilesHelper->SetTileWindowSize(actual_size);
      tilesHelper->GetPhysicalViewport(physical_viewport, rank, this->PhysicalViewport);
      tilesHelper->SetTileMullions(tile_mullions);
      tilesHelper->SetTileWindowSize(tile_size);
      }
    else
      {
      tilesHelper->GetPhysicalViewport(viewport, rank, this->PhysicalViewport);
      }
    }
  else
    {
    this->LastTileViewport[0] = this->LastTileViewport[1] = 0;
    this->LastTileViewport[2] = this->LastTileViewport[3] = -1;
    this->PhysicalViewport[0] = this->PhysicalViewport[1] =
      this->PhysicalViewport[2] = this->PhysicalViewport[3] = 0.0;
    }
  vtkDebugMacro("Physical Viewport: "
    << this->PhysicalViewport[0] << ", "
    << this->PhysicalViewport[1] << ", "
    << this->PhysicalViewport[2] << ", "
    << this->PhysicalViewport[3]);

  if (this->LastTileMullions[0] == tile_mullions[0] &&
    this->LastTileMullions[1] == tile_mullions[1] &&
    this->LastTileDimensions[0] == this->TileDimensions[0] &&
    this->LastTileDimensions[1] == this->TileDimensions[1])
    {
    // No need to update the tile parameters.
    //return;
    }

  //cout << "icetResetTiles" << endl;
  icetResetTiles();
  for (int x=0; x < this->TileDimensions[0]; x++)
    {
    for (int y=0; y < this->TileDimensions[1]; y++)
      {
      int cur_rank  = y * this->TileDimensions[0] + x;
      int tile_viewport[4];
      if (!tilesHelper->GetTileViewport(viewport, cur_rank, tile_viewport))
        {
        continue;
        }

      vtkDebugMacro(<< this << "=" << cur_rank << " : "
        << tile_viewport[0]/image_reduction_factor << ", "
        << tile_viewport[1]/image_reduction_factor << ", "
        << tile_viewport[2]/image_reduction_factor << ", "
        << tile_viewport[3]/image_reduction_factor);

      // SYNTAX:
      // icetAddTile(x, y, width, height, display_rank);
      icetAddTile(
        static_cast<IceTInt>(tile_viewport[0]/image_reduction_factor),
        static_cast<IceTInt>(tile_viewport[1]/image_reduction_factor),
        static_cast<IceTSizeType>(
          (tile_viewport[2] - tile_viewport[0])/image_reduction_factor + 1),
        static_cast<IceTSizeType>(
          (tile_viewport[3] - tile_viewport[1])/image_reduction_factor + 1),
        cur_rank);
      ///cout << "icetAddTile: " <<
      ///  static_cast<IceTInt>(tile_viewport[0]/image_reduction_factor) << ", " <<
      ///  static_cast<IceTInt>(tile_viewport[1]/image_reduction_factor) << ", " <<
      ///  static_cast<IceTSizeType>(
      ///    (tile_viewport[2] - tile_viewport[0])/image_reduction_factor + 1) << ", " <<
      ///  static_cast<IceTSizeType>(
      ///    (tile_viewport[3] - tile_viewport[1])/image_reduction_factor + 1) << ", " <<
      ///  cur_rank << endl;

      // setting this should be needed so that the 2d actors work correctly.
      // However that messes up the tile-displays with tdy > 0
      // if (cur_rank == rank)
      //   {
      //   render_state->GetRenderer()->GetVTKWindow()->SetTileScale(this->TileDimensions);
      //   render_state->GetRenderer()->GetVTKWindow()->SetTileViewport(
      //     tile_viewport[0]/(double) (tile_size[0]*this->TileDimensions[0]),
      //     tile_viewport[1]/(double) (tile_size[1]*this->TileDimensions[1]),
      //     tile_viewport[2]/(double) (tile_size[0]*this->TileDimensions[0]),
      //     tile_viewport[3]/(double) (tile_size[1]*this->TileDimensions[1]));
      //   }
      }
    }

  this->LastTileMullions[0] = tile_mullions[0];
  this->LastTileMullions[1] = tile_mullions[1];
  this->LastTileDimensions[0] = this->TileDimensions[0];
  this->LastTileDimensions[1] = this->TileDimensions[1];
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::GetLastRenderedTile(
  vtkSynchronizedRenderers::vtkRawImage& tile)
{
  tile.MarkInValid();
  if (!this->LastRenderedRGBAColors->IsValid() ||
    this->LastRenderedRGBAColors->GetWidth() < 1 ||
    this->LastRenderedRGBAColors->GetHeight() < 1)
    {
    return;
    }

  tile = (*this->LastRenderedRGBAColors);
}

//----------------------------------------------------------------------------
vtkFloatArray* vtkIceTCompositePass::GetLastRenderedDepths()
{
  return this->LastRenderedDepths->GetNumberOfTuples() >  0 ?
    this->LastRenderedDepths.GetPointer() : NULL;
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::PushIceTDepthBufferToScreen(
  const vtkRenderState* render_state)
{
  vtkOpenGLClearErrorMacro();

  // OpenGL code to copy it back
  // merly the code from vtkCompositeZPass

  // get the dimension of the buffer
  IceTInt id;
  icetGetIntegerv(ICET_TILE_DISPLAYED,&id);
  if (id < 0)
    {
    // current processes is not displaying any tile.
    return;
    }

  IceTInt ids;
  icetGetIntegerv(ICET_NUM_TILES,&ids);

  IceTInt *vp=new IceTInt[4*ids];

  icetGetIntegerv(ICET_TILE_VIEWPORTS,vp);

  // IceTInt x=vp[4*id];
  // IceTInt y=vp[4*id+1];
  IceTInt w=vp[4*id+2];
  IceTInt h=vp[4*id+3];
  delete[] vp;

  if (this->LastRenderedDepths->GetNumberOfTuples() != w*h)
    {
    vtkErrorMacro(<< "Tile viewport size (" << w << "x" << h << ") does not"
                  << " match captured depth image ("
                  << this->LastRenderedDepths->GetNumberOfTuples() << ")");
    return;
    }

  float *depthBuffer=this->LastRenderedDepths->GetPointer(0);

  // pbo arguments.
  unsigned int dims[2];
  vtkIdType continuousInc[3];

  dims[0]=static_cast<unsigned int>(w);
  dims[1]=static_cast<unsigned int>(h);
  continuousInc[0]=0;
  continuousInc[1]=0;
  continuousInc[2]=0;

  vtkOpenGLRenderWindow *context=
    vtkOpenGLRenderWindow::SafeDownCast(
      render_state->GetRenderer()->GetRenderWindow());

  if(this->PBO==0)
    {
    this->PBO=vtkPixelBufferObject::New();
    this->PBO->SetContext(context);
    }
  if(this->ZTexture==0)
    {
    this->ZTexture=vtkTextureObject::New();
    this->ZTexture->SetContext(context);
    }

  // client to PBO
  this->PBO->Upload2D(VTK_FLOAT,depthBuffer,dims,1,continuousInc);

  // PBO to TO
  this->ZTexture->CreateDepth(dims[0],dims[1],vtkTextureObject::Native,
    this->PBO);

  // TO to FB: apply TO on quad with special zcomposite fragment shader.
  glPushAttrib(GL_DEPTH_BUFFER_BIT|GL_COLOR_BUFFER_BIT);
  glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
  glEnable(GL_DEPTH_TEST);
  glDepthMask(GL_TRUE);
  glDepthFunc(GL_ALWAYS);

  if(this->Program==0)
    {
    this->CreateProgram(context);
    }

#ifdef VTKGL2
  context->GetShaderCache()->ReadyShader(this->Program->Program);
  this->ZTexture->Activate();
  this->Program->Program->SetUniformi("depth", this->ZTexture->GetTextureUnit());
  this->ZTexture->CopyToFrameBuffer(0, 0, w - 1, h - 1,
                                    0, 0, w, h,
                                    this->Program->Program,
                                    &this->Program->vao);
  this->ZTexture->Deactivate();
#else
  vtkTextureUnitManager *tu=context->GetTextureUnitManager();
  int sourceId=tu->Allocate();
  this->Program->GetUniformVariables()->SetUniformi("depth",1,&sourceId);
  vtkgl::ActiveTexture(vtkgl::TEXTURE0+static_cast<GLenum>(sourceId));
  this->Program->Use();
  this->ZTexture->Bind();
  this->ZTexture->CopyToFrameBuffer(0,0,
    w-1,h-1,
    0,0,w,h);
  this->ZTexture->UnBind();
  this->Program->Restore();

  tu->Free(sourceId);
  vtkgl::ActiveTexture(vtkgl::TEXTURE0);
#endif

  glPopAttrib();

  vtkOpenGLCheckErrorMacro("failed after PushIceTDepthBufferToScreen");
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::PushIceTColorBufferToScreen(
  const vtkRenderState* render_state)
{
  vtkOpenGLClearErrorMacro();

  // get the dimension of the buffer
  IceTInt id;
  icetGetIntegerv(ICET_TILE_DISPLAYED,&id);
  if (id < 0)
    {
    // current processes is not displaying any tile.
    return;
    }

  IceTInt ids;
  icetGetIntegerv(ICET_NUM_TILES,&ids);

  IceTInt *vp=new GLint[4*ids];

  icetGetIntegerv(ICET_TILE_VIEWPORTS,vp);

  // IceTInt x=vp[4*id];
  // IceTInt y=vp[4*id+1];
  IceTInt w=vp[4*id+2];
  IceTInt h=vp[4*id+3];
  delete[] vp;

  // pbo arguments.
  unsigned int dims[2];
  vtkIdType continuousInc[3];

  dims[0]=static_cast<unsigned int>(w);
  dims[1]=static_cast<unsigned int>(h);
  continuousInc[0]=0;
  continuousInc[1]=0;
  continuousInc[2]=0;

  // merly the code from vtkCompositeRGBAPass

  glPushAttrib(GL_DEPTH_BUFFER_BIT|GL_COLOR_BUFFER_BIT|GL_LIGHTING);
  glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);

  // per-fragment operations
  glDisable(GL_ALPHA_TEST);
  glDisable(GL_STENCIL_TEST);
  glDisable(GL_DEPTH_TEST);
  glDisable(GL_BLEND);
  glDisable(GL_INDEX_LOGIC_OP);
  glDisable(GL_COLOR_LOGIC_OP);


  glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_REPLACE);
  glPixelStorei(GL_UNPACK_ALIGNMENT,1);// client to server

  vtkOpenGLRenderWindow *context=
    vtkOpenGLRenderWindow::SafeDownCast(
      render_state->GetRenderer()->GetRenderWindow());

#ifdef VTKGL2
  // framebuffers have their color premultiplied by alpha.
  glBlendFuncSeparate(GL_ONE,GL_ONE_MINUS_SRC_ALPHA,
    GL_ONE,GL_ONE_MINUS_SRC_ALPHA);
  this->BackgroundTexture->CopyToFrameBuffer(0, 0, w - 1, h - 1,
                                    0, 0, w, h, NULL, NULL);
#else
  // framebuffers have their color premultiplied by alpha.
  vtkgl::BlendFuncSeparate(GL_ONE,GL_ONE_MINUS_SRC_ALPHA,
    GL_ONE,GL_ONE_MINUS_SRC_ALPHA);

  // fixed vertex shader
  glDisable(GL_LIGHTING);

  // fixed fragment shader
  glEnable(GL_TEXTURE_2D);
  glDisable(GL_FOG);

  // Copy background to colorbuffer
  vtkgl::ActiveTexture(vtkgl::TEXTURE0);
  // fixed-pipeline for vertex and fragment shaders.
  this->BackgroundTexture->Bind();
  this->BackgroundTexture->CopyToFrameBuffer(0,0,w-1,h-1,0,0,w,h);
  this->BackgroundTexture->UnBind();
#endif

  // Apply (with blending) IceT color buffer on top of background

  if(this->PBO==0)
    {
    this->PBO=vtkPixelBufferObject::New();
    this->PBO->SetContext(context);
    }
  if(this->IceTTexture==0)
    {
    this->IceTTexture=vtkTextureObject::New();
    this->IceTTexture->SetContext(context);
    }

  if (this->LastRenderedRGBAColors->GetRawPtr()->GetNumberOfTuples() != w*h)
    {
    vtkErrorMacro(<< "Tile viewport size (" << w << "x" << h << ") does not"
      << " match captured color image ("
      << this->LastRenderedRGBAColors->GetRawPtr()->GetNumberOfTuples() << ")");
    return;
    }

  unsigned char *rgbaBuffer=this->LastRenderedRGBAColors->GetRawPtr()->GetPointer(0);

  // client to PBO
  this->PBO->Upload2D(VTK_UNSIGNED_CHAR,rgbaBuffer,dims,4,continuousInc);

  // PBO to TO
  this->IceTTexture->Create2D(dims[0],dims[1],4,this->PBO,false);

  glEnable(GL_BLEND);

#ifdef VTKGL2
  this->IceTTexture->CopyToFrameBuffer(0, 0, w - 1, h - 1,
                                    0, 0, w, h, NULL, NULL);
#else
  vtkgl::ActiveTexture(vtkgl::TEXTURE0);
  // fixed-pipeline for vertex and fragment shaders.
  this->IceTTexture->Bind();
  this->IceTTexture->CopyToFrameBuffer(0,0,w-1,h-1,0,0,w,h);
  this->IceTTexture->UnBind();
#endif

  glPopAttrib();

  vtkOpenGLCheckErrorMacro("failed after PushIceTColorBufferToScreen");
}

//----------------------------------------------------------------------------
void vtkIceTCompositePass::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);

  os << indent << "Controller: " << this->Controller << endl;
  os << indent << "RenderPass: " << this->RenderPass << endl;
  os << indent << "TileDimensions: "
     << this->TileDimensions[0] << ", " << this->TileDimensions[1] << endl;
  os << indent << "TileMullions: "
     << this->TileMullions[0] << ", " << this->TileMullions[1] << endl;
  os << indent << "DataReplicatedOnAllProcesses: "
     << this->DataReplicatedOnAllProcesses << endl;
  os << indent << "ImageReductionFactor: "
     << this->ImageReductionFactor << endl;
  os << indent << "KdTree: " << this->KdTree << endl;
  os << indent << "UseOrderedCompositing: "
     << this->UseOrderedCompositing << endl;
  os << indent << "DepthOnly: " << this->DepthOnly << endl;
  os << indent << "FixBackground: " << this->FixBackground << endl;
  os << indent << "PhysicalViewport: "
     << this->PhysicalViewport[0] << ", " << this->PhysicalViewport[1]
     << this->PhysicalViewport[2] << ", " << this->PhysicalViewport[3] << endl;
}
