Method RequestData

Filters/General/vtkMarchingContourFilter.cxx:82–141

General contouring filter. Handles arbitrary input.

// General contouring filter.  Handles arbitrary input.
//
int vtkMarchingContourFilter::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  // 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()));
  vtkPolyData* output = vtkPolyData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  vtkDataArray* inScalars;
  vtkIdType numCells;

  vtkDebugMacro(<< "Executing marching contour filter");

  numCells = input->GetNumberOfCells();
  inScalars = input->GetPointData()->GetScalars();
  if (!inScalars || numCells < 1)
  {
    vtkErrorMacro(<< "No data to contour");
    return 1;
  }

  // If structured points, use more efficient algorithms
  if ((input->GetDataObjectType() == VTK_STRUCTURED_POINTS))
  {
    if (inScalars->GetDataType() != VTK_BIT)
    {
      int dim = input->GetCell(0)->GetCellDimension();

      if (input->GetCell(0)->GetCellDimension() >= 2)
      {
        vtkDebugMacro(<< "Structured Points");
        this->StructuredPointsContour(dim, input, output);
        return 1;
      }
    }
  }

  if ((input->GetDataObjectType() == VTK_IMAGE_DATA))
  {
    if (inScalars->GetDataType() != VTK_BIT)
    {
      int dim = input->GetCell(0)->GetCellDimension();

      if (input->GetCell(0)->GetCellDimension() >= 2)
      {
        vtkDebugMacro(<< "Image");
        this->ImageContour(dim, input, output);
        return 1;
      }
    }
  }

  vtkDebugMacro(<< "Unoptimized");
  this->DataSetContour(input, output);