Method GenerateCellSurface

Filters/HyperTree/vtkHyperTreeGridGeometry3DImpl.cxx:196–298

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void vtkHyperTreeGridGeometry3DImpl::GenerateCellSurface(
  vtkHyperTreeGridNonOrientedVonNeumannSuperCursor* cursor,
  unsigned char vtkNotUsed(coarseCellFacesToBeTreated), vtkIdType cellId)
{
  // Determine if the current cell contains an interface and
  // fill the related member variables accordingly
  this->ProbeForCellInterface(cellId);

  // Retrieve info about the current cell
  unsigned level = cursor->GetLevel();
  bool masked = cursor->IsMasked();
  const double* cellOrigin = cursor->GetOrigin();
  const double* cellSize = cursor->GetSize();

  std::vector<HTG3DPoint> cellPoints;
  cellPoints.resize(NUMBER_OF_POINTS);
  std::vector<std::pair<HTG3DPoint, HTG3DPoint>> edgePoints;
  edgePoints.resize(NUMBER_OF_EDGES + MAX_NUMBER_OF_INTERFACE_EDGES);

  std::map<unsigned int, std::pair<HTG3DPoint*, unsigned int>> internalFaceA;
  std::map<unsigned int, std::pair<HTG3DPoint*, unsigned int>> internalFaceB;

  // Iterate over all neighboring cells using the Von Neumann neighborhood
  for (unsigned int faceId = 0; faceId < 6; ++faceId)
  {
    const unsigned int& neighborId = ::VON_NEUMANN_NEIGH_ID[faceId];
    const unsigned int& faceOrientation = ::FACE_ORIENTATION[faceId];
    const unsigned int& faceOffset = ::FACE_OFFSET[faceId];

    // Retrieve cursor to neighbor across face
    // Retrieve tree, leaf flag, and mask of neighbor cursor
    bool leafN = false;
    vtkIdType neighborCellId = 0;
    unsigned int levelN = 0;
    vtkHyperTree* treeN = cursor->GetInformation(neighborId, levelN, leafN, neighborCellId);
    int maskedN = cursor->IsMasked(neighborId);
    bool hasInterfaceCellN = this->GetHasInterface(cursor->GetGlobalNodeIndex(neighborId));

    // We generate a face if one of the following conditions are fulfilled:
    // - The current cell is unmasked, and the neighboring cell is masked
    // - The current cell is unmasked, and has no neighbouring cell
    // - The current cell is unmasked, and has an interface
    // - The current cell is unmasked, and has the neighboring cell has an interface
    // - The current cell is masked, and has a neighbor that is a non-masked leaf of lower level
    // This ensures that faces between unmasked and masked cells will be generated once and only
    // once.
    if ((!masked && (!treeN || maskedN || this->HasInterfaceOnThisCell || hasInterfaceCellN)) ||
      (masked && treeN && leafN && levelN < level && !maskedN))
    {
      // Generate face with corresponding normal and offset
      // Here we differentiate the case where the current cell is masked.
      // In that case, we must copy the data from the neighboring cell to the created face,
      // and not from the current cell.
      this->GenerateOneCellFace(cellPoints, edgePoints, faceId, (masked ? neighborCellId : cellId),
        cellOrigin, cellSize, faceOffset, faceOrientation, internalFaceA, internalFaceB);
    }
  }