Method RequestData

Filters/General/vtkApproximatingSubdivisionFilter.cxx:21–128

vtkApproximatingSubdivisionFilter::vtkApproximatingSubdivisionFilter() = default;

int vtkApproximatingSubdivisionFilter::RequestData(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (!this->Superclass::RequestData(request, inputVector, outputVector))
  {
    return 0;
  }

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

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

  vtkIdType numCells, numPts;
  int level;
  vtkPoints* outputPts;

  vtkCellArray* outputPolys;
  vtkPointData* outputPD;
  vtkCellData* outputCD;
  vtkIntArray* edgeData;

  vtkDebugMacro(<< "Generating subdivision surface using approximating scheme");
  numPts = input->GetNumberOfPoints();
  numCells = input->GetNumberOfCells();

  //
  // Initialize and check input
  //

  vtkPolyData* inputDS = vtkPolyData::New();
  inputDS->CopyStructure(input);
  inputDS->CopyAttributes(input);

  bool abort = false;
  for (level = 0; level < this->NumberOfSubdivisions && !abort; level++)
  {
    this->UpdateProgress(static_cast<double>(level + 1) / this->NumberOfSubdivisions);
    abort = this->CheckAbort();

    // Generate topology for the input dataset
    inputDS->BuildLinks();

    numCells = inputDS->GetNumberOfCells();
    numPts = inputDS->GetNumberOfPoints();

    // The points for the subdivisions will
    // include even points (computed from old points) and
    // odd points (inserted on edges)
    outputPts = vtkPoints::New();
    outputPts->Allocate(numPts);

    // Copy pointdata structure from input
    outputPD = vtkPointData::New();
    outputPD->CopyAllocate(inputDS->GetPointData(), 2 * inputDS->GetNumberOfPoints());