Method SetMergeGhostGrid

Filters/ParallelGeometry/vtkPDistributedDataFilter.cxx:4172–4257

// Delete all grids except the new merged grid.

vtkUnstructuredGrid* vtkPDistributedDataFilter::SetMergeGhostGrid(
  vtkUnstructuredGrid* ghostCellGrid, vtkUnstructuredGrid* incomingGhostCells, int ghostLevel,
  vtkPDistributedDataFilterSTLCloak* idMap)

{
  TimeLog timer("SetMergeGhostGrid", this->Timing);
  (void)timer;

  int i;

  if (incomingGhostCells->GetNumberOfCells() < 1)
  {
    if (incomingGhostCells != nullptr)
    {
      incomingGhostCells->Delete();
    }
    return ghostCellGrid;
  }

  // Set the ghost level of all new cells, and set the ghost level of all
  // the points.  We know some points in the new grids actually have ghost
  // level one lower, because they were on the boundary of the previous
  // grid.  This is OK if ghostLevel is > 1.  When we merge, vtkMergeCells
  // will skip these points because they are already in the previous grid.
  // But if ghostLevel is 1, those boundary points were in our original
  // grid, and we need to use the global ID map to determine if the
  // point ghost levels should be set to 0.

  vtkUnsignedCharArray* cellGL = incomingGhostCells->GetCellGhostArray();
  vtkUnsignedCharArray* ptGL = incomingGhostCells->GetPointGhostArray();

  unsigned char* ia = cellGL->GetPointer(0);

  for (i = 0; i < incomingGhostCells->GetNumberOfCells(); i++)
  {
    ia[i] = (unsigned char)ghostLevel;
  }

  ia = ptGL->GetPointer(0);

  for (i = 0; i < incomingGhostCells->GetNumberOfPoints(); i++)
  {
    ia[i] = (unsigned char)ghostLevel;
  }

  // now merge

  vtkUnstructuredGrid* mergedGrid = incomingGhostCells;

  if (ghostCellGrid && (ghostCellGrid->GetNumberOfCells() > 0))
  {
    vtkDataSet* sets[2];

    sets[0] = ghostCellGrid; // both sets will be deleted by MergeGrids
    sets[1] = incomingGhostCells;

    int useGlobalNodeIds = (this->GetGlobalNodeIds(ghostCellGrid) ? 1 : 0);
    mergedGrid =