Method DivideRegion

Filters/Parallel/vtkPKdTree.cxx:704–856

  return returnVal;
}
int vtkPKdTree::DivideRegion(vtkKdNode* kd, int L, int level, int tag)
{
  if (!this->DivideTest(kd->GetNumberOfPoints(), level))
    return -1;

  int numpoints = kd->GetNumberOfPoints();
  int R = L + numpoints - 1;

  if (numpoints < 2)
  {
    // Special case: not enough points to go around.
    int p = this->WhoHas(L);
    if (this->MyId != p)
      return -1;

    int maxdim = this->SelectCutDirection(kd);
    kd->SetDim(maxdim);

    vtkKdNode* left = vtkKdNode::New();
    vtkKdNode* right = vtkKdNode::New();
    kd->AddChildNodes(left, right);

    double bounds[6];
    kd->GetBounds(bounds);

    float* val = this->GetLocalVal(L);

    double coord;
    if (numpoints > 0)
    {
      coord = val[maxdim];
    }
    else
    {
      coord = (bounds[maxdim * 2] + bounds[maxdim * 2 + 1]) * 0.5;
    }

    left->SetBounds(bounds[0], ((maxdim == XDIM) ? coord : bounds[1]), bounds[2],
      ((maxdim == YDIM) ? coord : bounds[3]), bounds[4], ((maxdim == ZDIM) ? coord : bounds[5]));

    left->SetNumberOfPoints(numpoints);

    right->SetBounds(((maxdim == XDIM) ? coord : bounds[0]), bounds[1],
      ((maxdim == YDIM) ? coord : bounds[2]), bounds[3], ((maxdim == ZDIM) ? coord : bounds[4]),
      bounds[5]);

    right->SetNumberOfPoints(0);

    // Set the data bounds tightly around L.  This will inevitably mean some
    // regions that are empty will have their data bounds outside of them.
    // Hopefully, that will not screw up anything down the road.
    left->SetDataBounds(val[0], val[0], val[1], val[1], val[2], val[2]);
    right->SetDataBounds(val[0], val[0], val[1], val[1], val[2], val[2]);

    // Return L as the midpoint to guarantee that both left and right trees
    // are "owned" by the same process as the parent.  This is important
    // because only one process has not culled this node in the tree.
    return L;