Method Update

Rendering/Volume/vtkEncodedGradientEstimator.cxx:142–225

}

void vtkEncodedGradientEstimator::Update()
{
  int scalarInputSize[3];
  double scalarInputAspect[3];
  double startSeconds, endSeconds;
  double startCPUSeconds, endCPUSeconds;

  if (!this->InputData)
  {
    vtkErrorMacro(<< "No input in gradient estimator.");
    return;
  }

  if (this->GetMTime() > this->BuildTime || this->DirectionEncoder->GetMTime() > this->BuildTime ||
    this->InputData->GetMTime() > this->BuildTime || !this->EncodedNormals)
  {

    startSeconds = vtkTimerLog::GetUniversalTime();
    startCPUSeconds = vtkTimerLog::GetCPUTime();

    // Get the dimensions of the data and its aspect ratio
    this->InputData->GetDimensions(scalarInputSize);
    this->InputData->GetSpacing(scalarInputAspect);

    // If we previously have allocated space for the encoded normals,
    // and this space is no longer the right size, delete it
    if (this->EncodedNormalsSize[0] != scalarInputSize[0] ||
      this->EncodedNormalsSize[1] != scalarInputSize[1] ||
      this->EncodedNormalsSize[2] != scalarInputSize[2])
    {
      delete[] this->EncodedNormals;
      this->EncodedNormals = nullptr;

      delete[] this->GradientMagnitudes;
      this->GradientMagnitudes = nullptr;
    }

    // Compute the number of encoded voxels
    vtkIdType encodedSize = scalarInputSize[0];
    encodedSize *= scalarInputSize[1];
    encodedSize *= scalarInputSize[2];

    // Allocate space for the encoded normals if necessary
    if (!this->EncodedNormals)
    {
      this->EncodedNormals = new unsigned short[encodedSize];
      this->EncodedNormalsSize[0] = scalarInputSize[0];
      this->EncodedNormalsSize[1] = scalarInputSize[1];
      this->EncodedNormalsSize[2] = scalarInputSize[2];
    }

    if (!this->GradientMagnitudes && this->ComputeGradientMagnitudes)
    {
      this->GradientMagnitudes = new unsigned char[encodedSize];
    }

    // Copy info that multi threaded function will need into temp variables
    memcpy(this->InputSize, scalarInputSize, 3 * sizeof(int));