Method RenderTexturedPolygon

Rendering/OpenGL2/vtkOpenGLImageSliceMapper.cxx:201–320

------------------------------------------------------------------------------ Load the given image extent into a texture and render it

//------------------------------------------------------------------------------
// Load the given image extent into a texture and render it
void vtkOpenGLImageSliceMapper::RenderTexturedPolygon(
  vtkRenderer* ren, vtkImageProperty* property, vtkImageData* input, int extent[6], bool recursive)
{
  // get the previous texture load time
  vtkMTimeType loadTime = this->LoadTime.GetMTime();

  // the render window, needed for state information
  vtkOpenGLRenderWindow* renWin = static_cast<vtkOpenGLRenderWindow*>(ren->GetRenderWindow());

  bool reuseTexture = true;

  // if context has changed, verify context capabilities
  if (renWin != this->RenderWindow || renWin->GetContextCreationTime() > loadTime)
  {
    this->RenderWindow = renWin;
    reuseTexture = false;
  }

  vtkOpenGLClearErrorMacro();

  // get information about the image
  int xdim, ydim; // orientation of texture wrt input image
  vtkImageSliceMapper::GetDimensionIndices(this->Orientation, xdim, ydim);

  // verify that the orientation and slice has not changed
  bool orientationChanged = (this->Orientation != this->LastOrientation);
  this->LastOrientation = this->Orientation;
  bool sliceChanged = (this->SliceNumber != this->LastSliceNumber);
  this->LastSliceNumber = this->SliceNumber;

  // get the mtime of the property, including the lookup table
  vtkMTimeType propertyMTime = 0;
  if (property)
  {
    propertyMTime = property->GetMTime();
    if (!this->PassColorData)
    {
      vtkScalarsToColors* table = property->GetLookupTable();
      if (table)
      {
        vtkMTimeType mtime = table->GetMTime();
        propertyMTime = std::max(mtime, propertyMTime);
      }
    }
  }

  // need to reload the texture
  if (this->Superclass::GetMTime() > loadTime || propertyMTime > loadTime ||
    input->GetMTime() > loadTime || orientationChanged || sliceChanged || recursive)
  {
    // get the data to load as a texture
    int xsize = this->TextureSize[0];
    int ysize = this->TextureSize[1];
    int bytesPerPixel = this->TextureBytesPerPixel;

    // whether to try to use the input data directly as the texture
    bool reuseData = true;