Method DetectOverlappingCells

Filters/ParallelDIY2/vtkOverlappingCellsDetector.cxx:687–826

---------------------------------------------------------------------------- Main collision detection algorithm.

//----------------------------------------------------------------------------
// Main collision detection algorithm.
bool vtkOverlappingCellsDetector::DetectOverlappingCells(vtkDataSet* queryCellDataSet,
  vtkPointSet* queryPointCloud, const std::vector<vtkBoundingBox>& queryCellBoundingBoxes,
  vtkDataSet* cellDataSet, vtkPointSet* pointCloud,
  const std::vector<vtkBoundingBox>& cellBoundingBoxes,
  std::unordered_map<vtkIdType, std::set<vtkIdType>>& collisionListMap, bool updateProgress)
{
  assert(cellDataSet->GetNumberOfCells() == pointCloud->GetNumberOfPoints() &&
    static_cast<vtkIdType>(cellBoundingBoxes.size()) == pointCloud->GetNumberOfPoints());
  assert(queryCellDataSet->GetNumberOfCells() == queryPointCloud->GetNumberOfPoints() &&
    static_cast<vtkIdType>(queryCellBoundingBoxes.size()) == queryPointCloud->GetNumberOfPoints());

  vtkAbstractPointLocator* locator = pointCloud->GetPointLocator();
  if (!locator)
  {
    pointCloud->BuildPointLocator();
    locator = pointCloud->GetPointLocator();
  }

  vtkDataArray* querySphereRadiusArray =
    queryPointCloud->GetPointData()->GetArray(SPHERE_RADIUS_ARRAY_NAME);

  vtkIdType querySize = queryPointCloud->GetNumberOfPoints();
  vtkIdType twentieth = querySize / 20 + 1;
  double decimal = 0.0;

  vtkNew<vtkIdTypeArray> queryNumberOfOverlapsPerCellsArray;
  queryNumberOfOverlapsPerCellsArray->SetNumberOfComponents(1);
  queryNumberOfOverlapsPerCellsArray->SetNumberOfTuples(querySize);
  queryNumberOfOverlapsPerCellsArray->SetName(this->GetNumberOfOverlapsPerCellArrayName());
  queryNumberOfOverlapsPerCellsArray->Fill(0.0);

  // Handling case where both input data sets point to the same address.
  vtkIdTypeArray* numberOfCollisionPerCellsArray = queryCellDataSet != cellDataSet
    ? vtkArrayDownCast<vtkIdTypeArray>(
        cellDataSet->GetCellData()->GetArray(this->GetNumberOfOverlapsPerCellArrayName()))
    : queryNumberOfOverlapsPerCellsArray;

  vtkNew<vtkIdList> neighborIds;

  // We want to discard ghost cells, so we have to acknowledge them.
  vtkUnsignedCharArray* queryCellGhostArray = queryCellDataSet->GetCellGhostArray();
  vtkUnsignedCharArray* cellGhostArray = cellDataSet->GetCellGhostArray();

  // local cell bank to avoid calling ::New() too many times.
  std::map<int, vtkSmartPointer<vtkCell>> cellBank, neighborCellBank;
  for (vtkIdType id = 0; id < querySize; ++id)
  {
    if (updateProgress)
    {
      // Update progress
      if (!(id % twentieth))
      {
        decimal += 0.05;
        this->UpdateProgress(decimal);
      }
    }
    if (queryCellGhostArray && queryCellGhostArray->GetValue(id))
    {