public static edge make_edge(point u, point v)
	{
	  edge e;

	  e = GlobalMembersMemory.get_edge();

	  e.onext = e.oprev = e.dnext = e.dprev = e;
	  e.org = u;
	  e.dest = v;
	  if (u.entry_pt == null)
	  {
		u.entry_pt = e;
	  }
	  if (v.entry_pt == null)
	  {
		v.entry_pt = e;
	  }
	  return e;
	}