Method FindLoops

Common/DataModel/vtkReebGraph.cxx:2162–2237

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

//------------------------------------------------------------------------------
void vtkReebGraph::Implementation::FindLoops()
{

  if (this->ArcLoopTable)
  {
    free(this->ArcLoopTable);
    this->ArcLoopTable = nullptr;
    this->LoopNumber = 0;
  }

  this->ConnectedComponentNumber = 0;

  int nstack = 0, mstack = 0;
  int* stack = nullptr;

  char* Ntouch = (char*)malloc(sizeof(char) * this->MainNodeTable.Size);
  char* Atouch = (char*)malloc(sizeof(char) * this->MainArcTable.Size);

  memset(Ntouch, 0, sizeof(char) * this->MainNodeTable.Size);

  for (int Node = 1; Node < this->MainNodeTable.Size; Node++)
  {
    // check that the node is clear
    if (this->GetNode(Node)->ArcUpId == -2)
      continue;

    if (!Ntouch[Node])
    {
      ++(this->ConnectedComponentNumber);

      memset(Atouch, 0, sizeof(bool) * this->MainArcTable.Size);

      Ntouch[Node] = 1;
      nstack = 0;
      vtkReebGraphStackPush(Node);

      while (vtkReebGraphStackSize())
      {

        int N = vtkReebGraphStackTop();
        vtkReebGraphStackPop();

        for (int dir = 0; dir <= 1; dir++)
        {
          for (vtkIdType A = (!dir) ? (this->GetNode(N)->ArcDownId) : (this->GetNode(N)->ArcUpId);
               A; A = (!dir) ? (this->GetArc(A)->ArcDwId1) : (this->GetArc(A)->ArcDwId0))
          {
            int M = (!dir) ? (this->GetArc(A)->NodeId0) : (this->GetArc(A)->NodeId1);

            if (Atouch[A])
              continue;

            if (!Ntouch[M])
            {
              vtkReebGraphStackPush(M);
            }
            else
            {