Method DivideRegion

Common/DataModel/vtkKdTree.cxx:1240–1310

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//------------------------------------------------------------------------------
int vtkKdTree::DivideRegion(vtkKdNode* kd, float* c1, int* ids, int level)
{
  int ok = this->DivideTest(kd->GetNumberOfPoints(), level);

  if (!ok)
  {
    return 0;
  }

  int maxdim = this->SelectCutDirection(kd);

  kd->SetDim(maxdim);

  int dim1 = maxdim; // best cut direction
  int dim2 = -1;     // other valid cut directions
  int dim3 = -1;

  int otherDirections = this->ValidDirections ^ (1 << maxdim);

  if (otherDirections)
  {
    int x = otherDirections & (1 << vtkKdTree::XDIM);
    int y = otherDirections & (1 << vtkKdTree::YDIM);
    int z = otherDirections & (1 << vtkKdTree::ZDIM);

    if (x)
    {
      dim2 = vtkKdTree::XDIM;

      if (y)
      {
        dim3 = vtkKdTree::YDIM;
      }
      else if (z)
      {
        dim3 = vtkKdTree::ZDIM;
      }
    }
    else if (y)
    {
      dim2 = vtkKdTree::YDIM;

      if (z)
      {
        dim3 = vtkKdTree::ZDIM;
      }
    }
    else if (z)
    {
      dim2 = vtkKdTree::ZDIM;
    }
  }

  this->DoMedianFind(kd, c1, ids, dim1, dim2, dim3);

  if (kd->GetLeft() == nullptr)
  {
    return 0; // unable to divide region further