Method ComputeNeighbors

Filters/Geometry/vtkStructuredGridConnectivity.cxx:246–278

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//------------------------------------------------------------------------------
void vtkStructuredGridConnectivity::ComputeNeighbors()
{
  // STEP 0: Acquire data description, i.e., determine how the structured data
  // is laid out, e.g., is it volumetric or 2-D along some plane, XY, XZ, or YZ.
  this->AcquireDataDescription();
  if (this->DataDescription == vtkStructuredData::VTK_STRUCTURED_EMPTY ||
    this->DataDescription == vtkStructuredData::VTK_STRUCTURED_SINGLE_POINT)
  {
    return;
  }

  // STEP 1: Establish neighbors based on the structured extents.
  for (unsigned int i = 0; i < this->NumberOfGrids; ++i)
  {
    this->SetBlockTopology(i);
    for (unsigned int j = i + 1; j < this->NumberOfGrids; ++j)
    {
      this->EstablishNeighbors(i, j);
    } // END for all j
  }   // END for all i

  // STEP 2: Fill the ghost arrays
  for (unsigned int i = 0; i < this->NumberOfGrids; ++i)
  {
    // NOTE: typically remote grids have nullptr ghost arrays, by this approach
    // ComputeNeighbors() can be called transparently from
    // vtkPStructuredGridConnectivity without any modification.
    if (this->GridPointGhostArrays[i] != nullptr)
    {
      this->FillGhostArrays(i, this->GridPointGhostArrays[i], this->GridCellGhostArrays[i]);
    }
  } // END for all grids
}

//------------------------------------------------------------------------------
void vtkStructuredGridConnectivity::SearchNeighbors(