Method Next

Common/DataModel/vtkCellTreeLocator.cxx:235–281

this returns n (the location in the CellTree) if it is a leaf or 0 if the point doesn't contain in the data domain

  // this returns n (the location in the CellTree) if it is a leaf or 0 if the point doesn't
  // contain in the data domain
  const CellTreeNode<T>* Next()
  {
    while (true)
    {
      if (this->StackPtr == this->Stack) // This means the point is not within the domain
      {
        return nullptr;
      }

      const TCellTreeNode* n = &this->Tree.Nodes.front() + *(--this->StackPtr);

      if (n->IsLeaf())
      {
        return n;
      }

      const double p = this->Pos[n->GetDimension()];
      const T left = n->GetLeftChildIndex();

      bool l = p <= n->GetLeftMaxValue();  // Check if the points is within the left subtree
      bool r = p >= n->GetRightMinValue(); // Check if the point is within the right subtree

      //  This means if there is an overlap region both left and right subtrees should
      //  be traversed
      if (l && r)
      {
        if (n->GetLeftMaxValue() - p < p - n->GetRightMinValue())
        {
          *(this->StackPtr++) = left;
          *(this->StackPtr++) = left + 1;
        }
        else
        {
          *(this->StackPtr++) = left + 1;
          *(this->StackPtr++) = left;
        }
      }
      else if (l)
      {
        *(this->StackPtr++) = left;
      }
      else if (r)
      {
        *(this->StackPtr++) = left + 1;
      }
    }
  }
};

//------------------------------------------------------------------------------