Method UpdateTransferFunctions

Rendering/Core/vtkVolume.cxx:503–673

}

void vtkVolume::UpdateTransferFunctions(vtkRenderer* vtkNotUsed(ren))
{
  int dataType;
  vtkPiecewiseFunction* sotf;
  vtkPiecewiseFunction* gotf;
  vtkPiecewiseFunction* graytf;
  vtkColorTransferFunction* rgbtf;
  int colorChannels;

  int arraySize;

  // Check that we have scalars
  if (this->Mapper == nullptr || this->Mapper->GetDataSetInput() == nullptr ||
    this->Mapper->GetDataSetInput()->GetPointData() == nullptr ||
    this->Mapper->GetDataSetInput()->GetPointData()->GetScalars() == nullptr)
  {
    vtkErrorMacro(<< "Need scalar data to volume render");
    return;
  }

  // What is the type of the data?
  dataType = this->Mapper->GetDataSetInput()->GetPointData()->GetScalars()->GetDataType();

  if (dataType == VTK_UNSIGNED_CHAR)
  {
    arraySize = 256;
  }
  else if (dataType == VTK_UNSIGNED_SHORT)
  {
    arraySize = 65536;
  }
  else
  {
    vtkErrorMacro("Unsupported data type");
    return;
  }

  int numComponents =
    this->Mapper->GetDataSetInput()->GetPointData()->GetScalars()->GetNumberOfComponents();

  for (int c = 0; c < numComponents; c++)
  {

    // Did our array size change? If so, free up all our previous arrays
    // and create new ones for the scalar opacity and corrected scalar
    // opacity
    if (arraySize != this->ArraySize)
    {
      delete[] this->ScalarOpacityArray[c];
      this->ScalarOpacityArray[c] = nullptr;

      delete[] this->CorrectedScalarOpacityArray[c];
      this->CorrectedScalarOpacityArray[c] = nullptr;

      delete[] this->GrayArray[c];
      this->GrayArray[c] = nullptr;

      delete[] this->RGBArray[c];