public int AppendVertex(Vector2D v)
{
int vid = vertices_refcount.Allocate();
int i = 2 * vid;
vertices.Insert(v[1], i + 1);
vertices.Insert(v[0], i);
vertex_edges.Insert(new List <int>(), vid);
UpdateTimeStamp(true);
return(vid);
}
int Add_edge(int a, int b, int gid)
{
if (b < a)
{
int t = b; b = a; a = t;
}
int eid = edges_refcount.Allocate();
int i = 3 * eid;
edges.Insert(a, i);
edges.Insert(b, i + 1);
edges.Insert(gid, i + 2);
vertex_edges[a].Add(eid);
vertex_edges[b].Add(eid);
return(eid);
}
