Method RequestData

Filters/Generic/vtkGenericContourFilter.cxx:95–263

------------------------------------------------------------------------------ General contouring filter. Handles arbitrary input.

//------------------------------------------------------------------------------
// General contouring filter.  Handles arbitrary input.
int vtkGenericContourFilter::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
  vtkGenericDataSet* input =
    vtkGenericDataSet::SafeDownCast(inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkPolyData* output = vtkPolyData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  vtkDebugMacro(<< "Executing contour filter");

  if (!input)
  {
    vtkErrorMacro("No input specified");
    return 1;
  }
  vtkPointData* outPd = output->GetPointData();
  vtkCellData* outCd = output->GetCellData();

  // Create objects to hold output of contour operation. First estimate
  // allocation size.
  vtkIdType numCells = input->GetNumberOfCells();
  vtkIdType estimatedSize = input->GetEstimatedSize();
  estimatedSize = estimatedSize / 1024 * 1024; // multiple of 1024
  estimatedSize = std::max<vtkIdType>(estimatedSize, 1024);

  vtkPoints* newPts = vtkPoints::New();
  newPts->Allocate(estimatedSize, estimatedSize);
  vtkCellArray* newVerts = vtkCellArray::New();
  newVerts->AllocateExact(estimatedSize, estimatedSize);
  vtkCellArray* newLines = vtkCellArray::New();
  newLines->AllocateExact(estimatedSize, estimatedSize);
  vtkCellArray* newPolys = vtkCellArray::New();
  newPolys->AllocateExact(estimatedSize, estimatedSize);

  // locator used to merge potentially duplicate points
  if (this->Locator == nullptr)
  {
    this->CreateDefaultLocator();
  }
  this->Locator->InitPointInsertion(newPts, input->GetBounds(), estimatedSize);

  // prepare the output attributes
  vtkGenericAttributeCollection* attributes = input->GetAttributes();
  vtkGenericAttribute* attribute;
  vtkDataArray* attributeArray;

  int c = attributes->GetNumberOfAttributes();
  vtkDataSetAttributes* secondaryAttributes;

  int attributeType;

  for (vtkIdType i = 0; i < c; ++i)
  {
    attribute = attributes->GetAttribute(i);