// returns true for both internal and mesh boundary edges
// tid_in and tid_out are triangles 'in' and 'out' of set, respectively
bool edge_is_boundary(int eid, ref int tid_in, ref int tid_out)
{
if (edges.Contains(eid) == false)
{
return(false);
}
tid_in = tid_out = NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID;
Index2i et = Mesh.GetEdgeT(eid);
if (et.b == NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID) // boundary edge!
{
tid_in = et.a;
tid_out = et.b;
return(true);
}
bool in0 = triangles[et.a];
bool in1 = triangles[et.b];
if (in0 != in1)
{
tid_in = (in0) ? et.a : et.b;
tid_out = (in0) ? et.b : et.a;
return(true);
}
return(false);
}
public MeshRegionBoundaryLoops(NGonsCore.geometry3Sharp.mesh.DMesh3 mesh, int[] RegionTris, bool bAutoCompute = true)
{
this.Mesh = mesh;
// make flag set for included triangles
triangles = new IndexFlagSet(mesh.MaxTriangleID, RegionTris.Length);
for (int i = 0; i < RegionTris.Length; ++i)
{
triangles[RegionTris[i]] = true;
}
// make flag set for included edges
// NOTE: this currently processes non-boundary-edges twice. Could
// avoid w/ another IndexFlagSet, but the check is inexpensive...
edges = new IndexFlagSet(mesh.MaxEdgeID, RegionTris.Length);
for (int i = 0; i < RegionTris.Length; ++i)
{
int tid = RegionTris[i];
Index3i te = Mesh.GetTriEdges(tid);
for (int j = 0; j < 3; ++j)
{
int eid = te[j];
if (!edges.Contains(eid))
{
Index2i et = mesh.GetEdgeT(eid);
if (et.b == NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID || triangles[et.a] != triangles[et.b])
{
edges.Add(eid);
}
}
}
}
if (bAutoCompute)
{
Compute();
}
}