Method GetGhostVector

Common/DataModel/vtkAMRBox.cxx:507–545

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

//------------------------------------------------------------------------------
void vtkAMRBox::GetGhostVector(int r, int nghost[6]) const
{
  // STEP 0: initialize nghost
  for (int i = 0; i < 3; ++i)
  {
    nghost[i * 2] = nghost[i * 2 + 1] = 0;
  }

  // STEP 1: compute number of ghost layers along each dimension's min and max.
  // Detecting partially overlapping boxes is based on the following:
  // Cell location k at level L-1 holds the range [k*r,k*r+(r-1)] of
  // level L, where r is the refinement ratio. Consequently, if the
  // min extent of the box is greater than k*r or if the max extent
  // of the box is less than k*r+(r-1), then the grid partially overlaps.

  vtkAMRBox coarsenedBox = *this;
  coarsenedBox.Coarsen(r);
  for (int i = 0; i < 3; ++i)
  {
    if (!this->EmptyDimension(i))
    {
      int minRange[2];
      minRange[0] = coarsenedBox.LoCorner[i] * r;
      minRange[1] = coarsenedBox.LoCorner[i] * r + (r - 1);
      if (this->LoCorner[i] > minRange[0])
      {
        nghost[i * 2] = (minRange[1] + 1) - this->LoCorner[i];
      }

      int maxRange[2];
      maxRange[0] = coarsenedBox.HiCorner[i] * r;
      maxRange[1] = coarsenedBox.HiCorner[i] * r + (r - 1);
      if (this->HiCorner[i] < maxRange[1])
      {
        nghost[i * 2 + 1] = this->HiCorner[i] - (maxRange[0] - 1);
      }
    }
  } // END for all dimensions
}

void vtkAMRBox::RemoveGhosts(int r)
{