Method GetPointsInsideBounds

Filters/ParallelMPI/vtkDistributedPointCloudFilter.cxx:385–595

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void vtkDistributedPointCloudFilter::GetPointsInsideBounds(vtkMPIController* controller,
  vtkPointSet* input, vtkPointSet* output, const double outterBounds[6])
{
  vtkMPICommunicator* com = vtkMPICommunicator::SafeDownCast(controller->GetCommunicator());
  int np = com ? com->GetNumberOfProcesses() : 1;
  int rank = com ? com->GetLocalProcessId() : 0;

  if (!com || np == 1)
  {
    output->ShallowCopy(input);
    return;
  }

  // round bounds to the nearest float value because locator use float internally.
  // Otherwise, points that are exactly on the bounds may be wrongly considered as outside
  // because of the cast.
  double localOutterBounds[6];
  for (int i = 0; i < 3; i++)
  {
    localOutterBounds[2 * i] = std::nextafter(
      static_cast<float>(outterBounds[2 * i]), static_cast<float>(outterBounds[2 * i]) - 1);
    localOutterBounds[2 * i + 1] = std::nextafter(
      static_cast<float>(outterBounds[2 * i + 1]), static_cast<float>(outterBounds[2 * i + 1]) + 1);
  }

  bool emptyData = input->GetNumberOfPoints() == 0;

  std::vector<double> allOutterBounds(np * 6);
  com->AllGather(localOutterBounds, allOutterBounds.data(), 6);

  // size in bytes of messages to be sent to other processes
  std::vector<vtkIdType> messagesSize(np);

  // number of points in messages to be sent to other processes
  std::vector<vtkIdType> messagePointCount(np);

  // array of point ids
  vtkNew<vtkIdTypeArray> idArray;
  std::vector<vtkSmartPointer<vtkCharArray>> dataToSend;
  dataToSend.resize(np);

  // we will need a locator to search points inside each processor assigned regions
  vtkNew<vtkOctreePointLocator> locator;

  if (!emptyData)
  {
    vtkNew<vtkPolyData> inputPolyData;
    inputPolyData->SetPoints(input->GetPoints());
    locator->SetDataSet(inputPolyData.Get());
    locator->BuildLocator();
  }

  // 1st step: define messages to send to each processor (including itself)
  // with polydata containing closest points to local data bounding box
  for (int partner = 0; partner < np; partner++)
  {
    idArray->SetNumberOfTuples(0);
    vtkIdType nPoints = 0;