/// <summary>
/// This is the method that actually does the work.
/// </summary>
/// <param name="DA">The DA object can be used to retrieve data from input parameters and
/// to store data in output parameters.</param>
protected override void SolveInstance(IGH_DataAccess DA)
{
Mesh M = new Mesh();
if (!DA.GetData(0, ref M)) return;
P_mesh PlanktonMesh = new P_mesh(M);
DA.SetData(0, PlanktonMesh);
}
// 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;
}