Method RequestData

Filters/General/vtkSampleImplicitFunctionFilter.cxx:137–218

------------------------------------------------------------------------------ Produce the output data

//------------------------------------------------------------------------------
// Produce the output data
int vtkSampleImplicitFunctionFilter::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  vtkDebugMacro(<< "Generating implicit data");

  // get the info objects
  vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
  vtkInformation* outInfo = outputVector->GetInformationObject(0);

  // get the input and output
  vtkDataSet* input = vtkDataSet::SafeDownCast(inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkDataSet* output = vtkDataSet::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  // Check the input
  if (!input || !output)
  {
    return 1;
  }
  vtkIdType numPts = input->GetNumberOfPoints();
  if (numPts < 1)
  {
    return 1;
  }

  // Ensure implicit function is specified
  //
  if (!this->ImplicitFunction)
  {
    vtkErrorMacro(<< "No implicit function specified");
    return 1;
  }

  // The output geometic structure is the same as the input
  output->CopyStructure(input);

  // Pass the output attribute data
  output->GetPointData()->PassData(input->GetPointData());
  output->GetCellData()->PassData(input->GetCellData());

  // Set up for execution
  vtkFloatArray* newScalars = vtkFloatArray::New();
  newScalars->SetNumberOfTuples(numPts);
  float* scalars = newScalars->WritePointer(0, numPts);

  vtkFloatArray* newGradients = nullptr;
  float* gradients = nullptr;
  if (this->ComputeGradients)
  {
    newGradients = vtkFloatArray::New();
    newGradients->SetNumberOfComponents(3);
    newGradients->SetNumberOfTuples(numPts);
    gradients = newGradients->WritePointer(0, numPts);
  }

  // Threaded execute
  if (this->ComputeGradients)
  {
    SampleDataSetWithGradients sample(input, this->ImplicitFunction, scalars, gradients, this);