Method MPIRedistribute

Filters/ParallelGeometry/vtkPDistributedDataFilter.cxx:2301–2369

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
vtkUnstructuredGrid* vtkPDistributedDataFilter::MPIRedistribute(
  vtkDataSet* in, vtkDataSet* input, int filterOutDuplicateCells)
{
  TimeLog timer("MPIRedistribute", this->Timing);
  (void)timer;

  int proc;
  int nprocs = this->NumProcesses;

  // A cell belongs to a spatial region if it's centroid lies in that
  // region.  The kdtree object can create a list for each region of the
  // IDs of each cell I have read in that belong in that region.  If we
  // are building subgrids of all cells that intersect a region (a
  // superset of all cells that belong to a region) then the kdtree object
  // can build another set of lists of all cells that intersect each
  // region (but don't have their centroid in that region).

  if (this->IncludeAllIntersectingCells)
  {
    // TO DO:
    // We actually compute whether a cell intersects a spatial region.
    // This can be a lengthy calculation.  Perhaps it's good enough
    // to compute whether a cell's bounding box intersects the region.
    // Some of the cells we list will actually not be in the region, but
    // if we are clipping later, it doesn't matter.
    //
    // Is there any rendering algorithm that needs exactly all cells
    // which intersect the region, and no more?

    this->Kdtree->IncludeRegionBoundaryCellsOn(); // SLOW!!
  }

  this->Kdtree->CreateCellLists(); // required by GetCellIdsForProcess

  vtkIdList*** procCellLists = new vtkIdList**[nprocs];
  int* numLists = new int[nprocs];

  for (proc = 0; proc < this->NumProcesses; proc++)
  {
    procCellLists[proc] = this->GetCellIdsForProcess(proc, numLists + proc);
  }

  int deleteDataSet = DeleteNo;

  if (in != input)
  {
    deleteDataSet = DeleteYes;
  }

  vtkUnstructuredGrid* myNewGrid = this->ExchangeMergeSubGrids(procCellLists, numLists, DeleteNo,
    in, deleteDataSet, filterOutDuplicateCells, GhostCellsNo, 0x0012);

  for (proc = 0; proc < nprocs; proc++)
  {
    delete[] procCellLists[proc];
  }

  delete[] procCellLists;