// public void ReIndex() //clear away all the dead elements to save space
// //maybe it is better to just create a fresh one rather than trying to shuffle the existing
// {
// }
public P_mesh Dual()
{
// can later add options for other ways of defining face centres (barycenter/circumcenter etc)
// won't work yet with naked boundaries
P_mesh P = this;
P_mesh D = new P_mesh();
//for every primal face, add the barycenter to the dual's vertex list
//dual vertex outgoing HE is primal face's start HE
//for every vertex of the primal, add a face to the dual
//dual face's startHE is primal vertex's outgoing's pair
for (int i = 0; i < P.Faces.Count; i++)
{
D.Vertices.Add(new P_vertex(P.FaceCentroid(i)));
List<int> FaceHalfedges = P.FaceHEs(i);
for (int j = 0; j < FaceHalfedges.Count; j++)
{
if (P.HalfEdges[P.PairHalfEdge(FaceHalfedges[j])].AdjacentFace != -1)
{
// D.Vertices[i].OutgoingHalfEdge = FaceHalfedges[j];
D.Vertices[D.Vertices.Count-1].OutgoingHalfEdge = P.PairHalfEdge(FaceHalfedges[j]);
break;
}
}
}
for (int i = 0; i < P.Vertices.Count; i++)
{
if (P.VertexNakedEdgeCount(i) == 0)
{
D.Faces.Add(new P_face());
// D.Faces[i].FirstHalfEdge = P.PairHalfEdge(P.Vertices[i].OutgoingHalfEdge);
D.Faces[D.Faces.Count-1].FirstHalfEdge = P.Vertices[i].OutgoingHalfEdge;
}
}
// dual halfedge start V is primal AdjacentFace
// dual halfedge AdjacentFace is primal end V
// dual nextHE is primal's pair's prev
// dual prevHE is primal's next's pair
// halfedge pairs stay the same
int newIndex = 0;
for (int i = 0; i < P.HalfEdges.Count; i++)
{
if ((P.HalfEdges[i].AdjacentFace != -1) & (P.HalfEdges[P.PairHalfEdge(i)].AdjacentFace != -1))
{
P_halfedge DualHE = new P_halfedge();
P_halfedge PrimalHE = P.HalfEdges[i];
//DualHE.StartVertex = PrimalHE.AdjacentFace;
DualHE.StartVertex = P.HalfEdges[P.PairHalfEdge(i)].AdjacentFace;
if (P.VertexNakedEdgeCount(PrimalHE.StartVertex) == 0)
{
//DualHE.AdjacentFace = P.HalfEdges[P.PairHalfEdge(i)].StartVertex;
DualHE.AdjacentFace = PrimalHE.StartVertex;
}
else { DualHE.AdjacentFace = -1; }
//This will currently fail with open meshes...
//one option could be to build the dual with all halfedges, but mark some as dead
//if they connect to vertex -1
//mark the 'external' faces all as -1 (the ones that are dual to boundary verts)
//then go through and if any next or prevs are dead hes then replace them with the next one around
//this needs to be done repeatedly until no further change
//DualHE.NextHalfEdge = P.HalfEdges[P.PairHalfEdge(i)].PrevHalfEdge;
DualHE.NextHalfEdge = P.PairHalfEdge(PrimalHE.PrevHalfEdge);
//DualHE.PrevHalfEdge = P.PairHalfEdge(PrimalHE.NextHalfEdge);
DualHE.PrevHalfEdge = P.HalfEdges[P.PairHalfEdge(i)].NextHalfEdge;
DualHE.Index = newIndex;
D.HalfEdges.Add(DualHE);
newIndex += 1;
}
}
return D;
}
//Create a Plankton Mesh from a Rhino Mesh
public P_mesh(Mesh M)
{
M.Vertices.CombineIdentical(true, true);
M.Vertices.CullUnused();
M.UnifyNormals();
M.Weld(Math.PI);
this.Faces = new List<P_face>();
this.HalfEdges = new List<P_halfedge>();
this.Vertices = new List<P_vertex>();
for (int i = 0; i < M.Vertices.Count; i++)
{
Vertices.Add(new P_vertex(M.TopologyVertices[i]));
}
for (int i = 0; i < M.Faces.Count; i++)
{Faces.Add(new P_face()); }
for (int i = 0; i < M.TopologyEdges.Count; i++)
{
P_halfedge HalfA = new P_halfedge();
HalfA.StartVertex = M.TopologyEdges.GetTopologyVertices(i).I;
if (Vertices[HalfA.StartVertex].OutgoingHalfEdge == -1)
{ Vertices[HalfA.StartVertex].OutgoingHalfEdge = HalfEdges.Count; }
P_halfedge HalfB = new P_halfedge();
HalfB.StartVertex = M.TopologyEdges.GetTopologyVertices(i).J;
if (Vertices[HalfB.StartVertex].OutgoingHalfEdge == -1)
{ Vertices[HalfB.StartVertex].OutgoingHalfEdge = HalfEdges.Count + 1; }
bool[] Match;
int[] ConnectedFaces = M.TopologyEdges.GetConnectedFaces(i, out Match);
//Note for Steve Baer : This Match bool doesn't seem to work on triangulated meshes - it often returns true
//for both faces, even for a properly oriented manifold mesh, which can't be right
//So - making our own check for matching:
//(I suspect the problem is related to C being the same as D for triangles, so best to
//deal with them separately just to make sure)
//loop through the vertices of the face until finding the one which is the same as the start of the edge
//iff the next vertex around the face is the end of the edge then it matches.
Match[0] = false;
if (Match.Length > 1)
{Match[1] = true;}
int VertA = M.TopologyVertices.TopologyVertexIndex(M.Faces[ConnectedFaces[0]].A);
int VertB = M.TopologyVertices.TopologyVertexIndex(M.Faces[ConnectedFaces[0]].B);
int VertC = M.TopologyVertices.TopologyVertexIndex(M.Faces[ConnectedFaces[0]].C);
int VertD = M.TopologyVertices.TopologyVertexIndex(M.Faces[ConnectedFaces[0]].D);
if ((VertA == M.TopologyEdges.GetTopologyVertices(i).I)
&& (VertB == M.TopologyEdges.GetTopologyVertices(i).J))
{ Match[0] = true;
}
if ((VertB == M.TopologyEdges.GetTopologyVertices(i).I)
&& (VertC == M.TopologyEdges.GetTopologyVertices(i).J))
{
Match[0] = true;
}
if ((VertC == M.TopologyEdges.GetTopologyVertices(i).I)
&& (VertD == M.TopologyEdges.GetTopologyVertices(i).J))
{
Match[0] = true;
}
if ((VertD == M.TopologyEdges.GetTopologyVertices(i).I)
&& (VertA == M.TopologyEdges.GetTopologyVertices(i).J))
{
Match[0] = true;
}
//I don't think these next 2 should ever be needed, but just in case:
if ((VertC == M.TopologyEdges.GetTopologyVertices(i).I)
&& (VertA == M.TopologyEdges.GetTopologyVertices(i).J))
{
Match[0] = true;
}
if ((VertB == M.TopologyEdges.GetTopologyVertices(i).I)
&& (VertD == M.TopologyEdges.GetTopologyVertices(i).J))
{
Match[0] = true;
}
if (Match[0] == true)
{
HalfA.AdjacentFace = ConnectedFaces[0];
if (Faces[HalfA.AdjacentFace].FirstHalfEdge == -1)
{ Faces[HalfA.AdjacentFace].FirstHalfEdge = HalfEdges.Count; }
if (ConnectedFaces.Length > 1)
{
HalfB.AdjacentFace = ConnectedFaces[1];
if (Faces[HalfB.AdjacentFace].FirstHalfEdge == -1)
{ Faces[HalfB.AdjacentFace].FirstHalfEdge = HalfEdges.Count + 1; }
}
else
{
HalfB.AdjacentFace = -1;
}
}
else
{
HalfB.AdjacentFace = ConnectedFaces[0];
if (Faces[HalfB.AdjacentFace].FirstHalfEdge == -1)
{ Faces[HalfB.AdjacentFace].FirstHalfEdge = HalfEdges.Count + 1; }
if (ConnectedFaces.Length > 1)
{
HalfA.AdjacentFace = ConnectedFaces[1];
if (Faces[HalfA.AdjacentFace].FirstHalfEdge == -1)
{ Faces[HalfA.AdjacentFace].FirstHalfEdge = HalfEdges.Count; }
}
else
{
HalfA.AdjacentFace = -1;
}
}
HalfEdges.Add(HalfA);
HalfEdges[2 * i].Index = 2 * i; //
HalfEdges.Add(HalfB);
HalfEdges[2 * i + 1].Index = 2 * i + 1; //
}
for (int i = 0; i < (HalfEdges.Count); i += 2)
{
int[] EndNeighbours = M.TopologyVertices.ConnectedTopologyVertices(HalfEdges[i + 1].StartVertex, true);
for (int j = 0; j < EndNeighbours.Length; j++)
{
if(EndNeighbours[j]==HalfEdges[i].StartVertex)
{
int EndOfNextHalfEdge = EndNeighbours[(j - 1 + EndNeighbours.Length) % EndNeighbours.Length];
int StartOfPrevOfPairHalfEdge = EndNeighbours[(j + 1) % EndNeighbours.Length];
int NextEdge = M.TopologyEdges.GetEdgeIndex(HalfEdges[i + 1].StartVertex,EndOfNextHalfEdge);
int PrevPairEdge = M.TopologyEdges.GetEdgeIndex(HalfEdges[i + 1].StartVertex,StartOfPrevOfPairHalfEdge);
if (M.TopologyEdges.GetTopologyVertices(NextEdge).I == HalfEdges[i + 1].StartVertex)
{ HalfEdges[i].NextHalfEdge = NextEdge * 2; }
else
{ HalfEdges[i].NextHalfEdge = NextEdge * 2 + 1; }
if (M.TopologyEdges.GetTopologyVertices(PrevPairEdge).J == HalfEdges[i + 1].StartVertex)
{ HalfEdges[i + 1].PrevHalfEdge = PrevPairEdge * 2; }
else
{ HalfEdges[i + 1].PrevHalfEdge = PrevPairEdge * 2+1; }
break;
}
}
int[] StartNeighbours = M.TopologyVertices.ConnectedTopologyVertices(HalfEdges[i].StartVertex, true);
for (int j = 0; j < StartNeighbours.Length; j++)
{
if (StartNeighbours[j] == HalfEdges[i+1].StartVertex)
{
int EndOfNextOfPairHalfEdge = StartNeighbours[(j - 1 + StartNeighbours.Length) % StartNeighbours.Length];
int StartOfPrevHalfEdge = StartNeighbours[(j + 1) % StartNeighbours.Length];
int NextPairEdge = M.TopologyEdges.GetEdgeIndex(HalfEdges[i].StartVertex, EndOfNextOfPairHalfEdge);
int PrevEdge = M.TopologyEdges.GetEdgeIndex(HalfEdges[i].StartVertex, StartOfPrevHalfEdge);
if (M.TopologyEdges.GetTopologyVertices(NextPairEdge).I == HalfEdges[i].StartVertex)
{ HalfEdges[i + 1].NextHalfEdge = NextPairEdge * 2; }
else
{ HalfEdges[i + 1].NextHalfEdge = NextPairEdge * 2 + 1; }
if (M.TopologyEdges.GetTopologyVertices(PrevEdge).J == HalfEdges[i].StartVertex)
{ HalfEdges[i].PrevHalfEdge = PrevEdge * 2; }
else
{ HalfEdges[i].PrevHalfEdge = PrevEdge * 2 + 1; }
break;
}
}
}
}
