Openmesh halfedge find vertex

placeholder

沒有充分理解iterator 的妙處，還狂找halfedge 的dereference!

halfedge connectivity.

  // --- halfedge connectivity ---
  VertexHandle to_vertex_handle(HalfedgeHandle _heh) const
  { return halfedge(_heh).vertex_handle_; }

  VertexHandle from_vertex_handle(HalfedgeHandle _heh) const
  { return to_vertex_handle(opposite_halfedge_handle(_heh)); }

  void set_vertex_handle(HalfedgeHandle _heh, VertexHandle _vh)
  {
//     assert(is_valid_handle(_vh));
    halfedge(_heh).vertex_handle_ = _vh;
  }

  FaceHandle face_handle(HalfedgeHandle _heh) const
  { return halfedge(_heh).face_handle_; }

  void set_face_handle(HalfedgeHandle _heh, FaceHandle _fh)
  {
//     assert(is_valid_handle(_fh));
    halfedge(_heh).face_handle_ = _fh;
  }

  void set_boundary(HalfedgeHandle _heh)
  { halfedge(_heh).face_handle_.invalidate(); }

  /// Is halfedge _heh a boundary halfedge (is its face handle invalid) ?
  bool is_boundary(HalfedgeHandle _heh) const
  { return !face_handle(_heh).is_valid(); }

  HalfedgeHandle next_halfedge_handle(HalfedgeHandle _heh) const
  { return halfedge(_heh).next_halfedge_handle_; }

  void set_next_halfedge_handle(HalfedgeHandle _heh, HalfedgeHandle _nheh)
  {
    assert(is_valid_handle(_nheh));
//     assert(to_vertex_handle(_heh) == from_vertex_handle(_nheh));
    halfedge(_heh).next_halfedge_handle_ = _nheh;
    set_prev_halfedge_handle(_nheh, _heh);
  }


  void set_prev_halfedge_handle(HalfedgeHandle _heh, HalfedgeHandle _pheh)
  {
    assert(is_valid_handle(_pheh));
    set_prev_halfedge_handle(_heh, _pheh, HasPrevHalfedge());
  }

  void set_prev_halfedge_handle(HalfedgeHandle _heh, HalfedgeHandle _pheh,
                                GenProg::True)
  { halfedge(_heh).prev_halfedge_handle_ = _pheh; }

  void set_prev_halfedge_handle(HalfedgeHandle /* _heh */, HalfedgeHandle /* _pheh */,
                                GenProg::False)
  {}

  HalfedgeHandle prev_halfedge_handle(HalfedgeHandle _heh) const
  { return prev_halfedge_handle(_heh, HasPrevHalfedge() ); }

  HalfedgeHandle prev_halfedge_handle(HalfedgeHandle _heh, GenProg::True) const
  { return halfedge(_heh).prev_halfedge_handle_; }

  HalfedgeHandle prev_halfedge_handle(HalfedgeHandle _heh, GenProg::False) const
  {
    if (is_boundary(_heh))
    {//iterating around the vertex should be faster than iterating the boundary
      HalfedgeHandle curr_heh(opposite_halfedge_handle(_heh));
      HalfedgeHandle next_heh(next_halfedge_handle(curr_heh));
      do
      {
        curr_heh = opposite_halfedge_handle(next_heh);
        next_heh = next_halfedge_handle(curr_heh);
      }
      while (next_heh != _heh);
      return curr_heh;
    }
    else
    {
      HalfedgeHandle  heh(_heh);
      HalfedgeHandle  next_heh(next_halfedge_handle(heh));
      while (next_heh != _heh) {
        heh = next_heh;
        next_heh = next_halfedge_handle(next_heh);
      }
      return heh;
    }
  }


  HalfedgeHandle opposite_halfedge_handle(HalfedgeHandle _heh) const
  { return HalfedgeHandle((_heh.idx() & 1) ? _heh.idx()-1 : _heh.idx()+1); }


  HalfedgeHandle ccw_rotated_halfedge_handle(HalfedgeHandle _heh) const
  { return opposite_halfedge_handle(prev_halfedge_handle(_heh)); }


  HalfedgeHandle cw_rotated_halfedge_handle(HalfedgeHandle _heh) const
  { return next_halfedge_handle(opposite_halfedge_handle(_heh)); }