/// <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);
}