Method UpdateColorTransferFunction

Rendering/VolumeOpenGL2/vtkVolumeInputHelper.cxx:146–192

}

int vtkVolumeInputHelper::UpdateColorTransferFunction(
  vtkRenderer* ren, vtkVolume* vol, unsigned int component)
{
  vtkVolumeProperty* volumeProperty = vol->GetProperty();

  // Build the colormap in a 1D texture. 1D RGB-texture-mapping from scalar
  // values to color values build the table.
  vtkColorTransferFunction* colorTransferFunction =
    volumeProperty->GetRGBTransferFunction(component);

  auto volumeTex = this->Texture.GetPointer();
  double componentRange[2];
  if (colorTransferFunction->GetSize() < 1 ||
    this->ColorRangeType == vtkGPUVolumeRayCastMapper::SCALAR)
  {
    for (int i = 0; i < 2; ++i)
    {
      componentRange[i] = volumeTex->ScalarRange[component][i];
    }
  }
  else
  {
    colorTransferFunction->GetRange(componentRange);
  }

  // Add points only if its not being added before
  if (colorTransferFunction->GetSize() < 1)
  {
    colorTransferFunction->AddRGBPoint(componentRange[0], 0.0, 0.0, 0.0);
    colorTransferFunction->AddRGBPoint(componentRange[1], 1.0, 1.0, 1.0);
  }

  int filterVal = volumeProperty->GetInterpolationType() == VTK_LINEAR_INTERPOLATION
    ? vtkTextureObject::Linear
    : vtkTextureObject::Nearest;

  this->RGBTables->GetTable(component)->Update(volumeProperty->GetRGBTransferFunction(component),
    componentRange, 0, 0, 0,
#ifndef GL_ES_VERSION_3_0
    filterVal,
#else
    vtkTextureObject::Nearest,
#endif
    vtkOpenGLRenderWindow::SafeDownCast(ren->GetRenderWindow()));

  return 0;
}

int vtkVolumeInputHelper::UpdateGradientOpacityTransferFunction(
  vtkRenderer* ren, vtkVolume* vol, unsigned int component, float samplingDist)