Method ComputeGradients

Rendering/Volume/vtkFixedPointVolumeRayCastMapper.cxx:2540–2696

}

void vtkFixedPointVolumeRayCastMapper::ComputeGradients(vtkVolume* vol)
{
  vtkImageData* input = vtkImageData::SafeDownCast(this->GetInput());

  auto* dataArray = this->CurrentScalars;

  int scalarType = this->CurrentScalars->GetDataType();
  int components = this->CurrentScalars->GetNumberOfComponents();
  int independent = vol->GetProperty()->GetIndependentComponents();

  int dim[3];
  double spacing[3];
  input->GetDimensions(dim);
  input->GetSpacing(spacing);

  // Find the scalar range
  double scalarRange[4][2];
  int c;
  for (c = 0; c < components; c++)
  {
    this->CurrentScalars->GetRange(scalarRange[c], c);
  }

  vtkIdType sliceSize = (static_cast<vtkIdType>(dim[0]) * static_cast<vtkIdType>(dim[1]) *
    ((independent) ? (components) : (1)));
  vtkIdType numSlices = dim[2];

  int i;

  // Delete the prior gradient normal information
  if (this->GradientNormal)
  {
    // Contiguous? Delete in one chunk otherwise delete slice by slice
    if (this->ContiguousGradientNormal)
    {
      delete[] this->ContiguousGradientNormal;
      this->ContiguousGradientNormal = nullptr;
    }
    else
    {
      for (i = 0; i < this->NumberOfGradientSlices; i++)
      {
        delete[] this->GradientNormal[i];
      }
    }
    delete[] this->GradientNormal;
    this->GradientNormal = nullptr;
  }

  // Delete the prior gradient magnitude information
  if (this->GradientMagnitude)
  {
    // Contiguous? Delete in one chunk otherwise delete slice by slice
    if (this->ContiguousGradientMagnitude)
    {
      delete[] this->ContiguousGradientMagnitude;
      this->ContiguousGradientMagnitude = nullptr;
    }