Method ReadConnectivity

IO/ParallelNetCDF/vtkPSLACReader.cxx:516–790

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

//------------------------------------------------------------------------------
int vtkPSLACReader::ReadConnectivity(
  int meshFD, vtkMultiBlockDataSet* surfaceOutput, vtkMultiBlockDataSet* volumeOutput)
{
  //---------------------------------
  // Call the superclass to read the arrays from disk and assemble the
  // primitives.  The superclass will call the ReadTetrahedron*Array methods,
  // which we have overridden to read only a partition of the cells.
  if (!this->Superclass::ReadConnectivity(meshFD, surfaceOutput, volumeOutput))
  {
    return 0;
  }

  //---------------------------------
  // Right now, the output only has blocks that are defined by the local piece.
  // However, downstream components will expect the multiblock structure to be
  // uniform amongst all processes.  Thus, we correct that problem here by
  // adding empty blocks for those not in our local piece.
  SynchronizeBlocks(surfaceOutput, this->Controller, IS_EXTERNAL_SURFACE());
  SynchronizeBlocks(volumeOutput, this->Controller, IS_INTERNAL_VOLUME());

  //---------------------------------
  // This multiblock that contains both outputs provides an easy way to iterate
  // over all cells in both output.
  vtkNew<vtkMultiBlockDataSet> compositeOutput;
  compositeOutput->SetNumberOfBlocks(2);
  compositeOutput->SetBlock(SURFACE_OUTPUT, surfaceOutput);
  compositeOutput->SetBlock(VOLUME_OUTPUT, volumeOutput);

  // ---------------------------------
  // All the cells have "global" ids.  That is, an index into a global list of
  // all possible points.  We don't want to have to read in all points in all
  // processes, so here we are going to figure out what points we need to load
  // locally, make maps between local and global ids, and convert the ids in the
  // connectivity arrays from global ids to local ids.

  this->PInternal->LocalToGlobalIds = vtkSmartPointer<vtkIdTypeArray>::New();
  this->PInternal->LocalToGlobalIds->SetName("GlobalIds");

  // Iterate over all points of all cells and mark what points we encounter
  // in GlobalToLocalIds.
  this->PInternal->GlobalToLocalIds.clear();
  vtkSmartPointer<vtkCompositeDataIterator> outputIter;
  for (outputIter.TakeReference(compositeOutput->NewIterator()); !outputIter->IsDoneWithTraversal();
       outputIter->GoToNextItem())
  {
    vtkUnstructuredGrid* ugrid =
      vtkUnstructuredGrid::SafeDownCast(compositeOutput->GetDataSet(outputIter));
    vtkCellArray* cells = ugrid->GetCells();

    vtkIdType npts;
    const vtkIdType* pts;
    for (cells->InitTraversal(); cells->GetNextCell(npts, pts);)
    {
      for (vtkIdType i = 0; i < npts; i++)
      {
        // The following inserts an entry into the map if one does not exist.
        // We will assign actual local ids later.
        this->PInternal->GlobalToLocalIds[pts[i]] = -1;