Method ValidateRender

Rendering/Volume/vtkGPUVolumeRayCastMapper.cxx:207–253

------------------------------------------------------------------------------ This method us used by the render method to validate everything before attempting to render. This method returns 0 if something is not right - such as missing input, a null renderer or a null volume, no scalars, etc. In some cases it will produce a vtkErrorMacro message, and in others (for example, in the case of croppi

// return with a value of 1.
//------------------------------------------------------------------------------
int vtkGPUVolumeRayCastMapper::ValidateRender(vtkRenderer* ren, vtkVolume* vol)
{
  // Check that we have everything we need to render.
  int goodSoFar = 1;

  // Check for a renderer - we MUST have one
  if (!ren)
  {
    goodSoFar = 0;
    vtkErrorMacro("Renderer cannot be null.");
  }

  // Check for the volume - we MUST have one
  if (goodSoFar && !vol)
  {
    goodSoFar = 0;
    vtkErrorMacro("Volume cannot be null.");
  }

  // Check the cropping planes. If they are invalid, just silently
  // fail. This will happen when an interactive widget is dragged
  // such that it defines 0 or negative volume - this can happen
  // and should just not render the volume.
  // Check the cropping planes
  if (goodSoFar && this->Cropping &&
    (this->CroppingRegionPlanes[0] >= this->CroppingRegionPlanes[1] ||
      this->CroppingRegionPlanes[2] >= this->CroppingRegionPlanes[3] ||
      this->CroppingRegionPlanes[4] >= this->CroppingRegionPlanes[5]))
  {
    // No error message here - we want to be silent
    goodSoFar = 0;
  }

  if (!goodSoFar)
  {
    return 0;
  }

  auto multiVol = vtkMultiVolume::SafeDownCast(vol);
  bool success = true;
  for (const auto& port : this->Ports)
  {
    auto currentVol = multiVol ? multiVol->GetVolume(port) : vol;
    success &= this->ValidateInput(currentVol->GetProperty(), port) == 1;
  }
  return (success ? 1 : 0);
}

vtkDataSet* vtkGPUVolumeRayCastMapper::FindData(int port, DataMap& container)
{