Beispiel #1
0
        /// <summary>
        /// Split edge in half
        /// </summary>
        /// <param name="m">Polymesh</param>
        /// <param name="eh">Edge Handle</param>
        /// <returns>New Half-edge Handle for the new Edge</returns>
        public static int SplitEdge(PolyMesh m, int eh)
        {
            int heh     = m.GetHalfedgeEdgeH(eh, 0);
            int opp_heh = m.GetHalfedgeEdgeH(eh, 1);

            int new_heh, opp_new_heh, t_heh;
            int vh, vh1 = m.GetEndVertexH(heh);

            Vector3 midP = m.GetPoint(vh1);

            midP += m.GetPoint(m.GetEndVertexH(opp_heh));
            midP *= 0.5f;

            // new vertex
            vh = m.AddVertex(midP);

            // Re-link mesh entities
            if (m.IsBoundaryEdge(eh))
            {
                for (t_heh = heh;
                     m.GetNextHalfedgeH(t_heh) != opp_heh;
                     t_heh = m.GetOppositeHalfedgeH(m.GetNextHalfedgeH(t_heh)))
                {
                }
            }
            else
            {
                for (t_heh = m.GetNextHalfedgeH(opp_heh);
                     m.GetNextHalfedgeH(t_heh) != opp_heh;
                     t_heh = m.GetNextHalfedgeH(t_heh))
                {
                }
            }

            new_heh     = m.NewEdge(vh, vh1);
            opp_new_heh = m.GetOppositeHalfedgeH(new_heh);
            m.SetVertexH(heh, vh);

            m.SetNextHalfedgeH(t_heh, opp_new_heh);
            m.SetNextHalfedgeH(new_heh, m.GetNextHalfedgeH(heh));
            m.SetNextHalfedgeH(heh, new_heh);
            m.SetNextHalfedgeH(opp_new_heh, opp_heh);

            if (m.GetFaceH(opp_heh).isValidHandle())
            {
                m.SetFaceH(opp_new_heh, m.GetFaceH(opp_heh));
                m.SetHalfedgeFaceH(m.GetFaceH(opp_new_heh), opp_new_heh);
            }

            m.SetFaceH(new_heh, m.GetFaceH(heh));
            m.SetHalfedgeVertexH(vh, new_heh);
            m.SetHalfedgeFaceH(m.GetFaceH(heh), heh);
            m.SetHalfedgeVertexH(vh1, opp_new_heh);

            // Never forget this, when playing with the topology
            m.AdjustOutgoingHalfedge(vh);
            m.AdjustOutgoingHalfedge(vh1);

            return(new_heh);
        }