Method InsertLeftEdge

CPP/Clipper2Lib/src/clipper.engine.cpp:1157–1186

  void ClipperBase::InsertLeftEdge(Active& e)
  {
    Active* e2;
    if (!actives_)
    {
      e.prev_in_ael = nullptr;
      e.next_in_ael = nullptr;
      actives_ = &e;
    }
    else if (!IsValidAelOrder(*actives_, e))
    {
      e.prev_in_ael = nullptr;
      e.next_in_ael = actives_;
      actives_->prev_in_ael = &e;
      actives_ = &e;
    }
    else
    {
      e2 = actives_;
      while (e2->next_in_ael && IsValidAelOrder(*e2->next_in_ael, e))
        e2 = e2->next_in_ael;
      if (e2->join_with == JoinWith::Right)
        e2 = e2->next_in_ael;
      if (!e2) return; // should never happen and stops compiler warning :)
      e.next_in_ael = e2->next_in_ael;
      if (e2->next_in_ael) e2->next_in_ael->prev_in_ael = &e;
      e.prev_in_ael = e2;
      e2->next_in_ael = &e;
    }
  }


  void InsertRightEdge(Active& e, Active& e2)