Method ProcessIntersectList

CPP/Clipper2Lib/src/clipper.engine.cpp:2448–2480

  }

  void ClipperBase::ProcessIntersectList()
  {
    //We now have a list of intersections required so that edges will be
    //correctly positioned at the top of the scanbeam. However, it's important
    //that edge intersections are processed from the bottom up, but it's also
    //crucial that intersections only occur between adjacent edges.

    //First we do a quicksort so intersections proceed in a bottom up order ...
    std::sort(intersect_nodes_.begin(), intersect_nodes_.end(), IntersectListSort);
    //Now as we process these intersections, we must sometimes adjust the order
    //to ensure that intersecting edges are always adjacent ...

    IntersectNodeList::iterator node_iter, node_iter2;
    for (node_iter = intersect_nodes_.begin();
      node_iter != intersect_nodes_.end();  ++node_iter)
    {
      if (!EdgesAdjacentInAEL(*node_iter))
      {
        node_iter2 = node_iter + 1;
        while (!EdgesAdjacentInAEL(*node_iter2)) ++node_iter2;
        std::swap(*node_iter, *node_iter2);
      }

      IntersectNode& node = *node_iter;
      IntersectEdges(*node.edge1, *node.edge2, node.pt);
      SwapPositionsInAEL(*node.edge1, *node.edge2);

      node.edge1->curr_x = node.pt.x;
      node.edge2->curr_x = node.pt.x;
      CheckJoinLeft(*node.edge2, node.pt, true);
      CheckJoinRight(*node.edge1, node.pt, true);
    }
  }

  void ClipperBase::SwapPositionsInAEL(Active& e1, Active& e2)
  {