public MeshGraph Clone()
{
MeshGraph mg = new MeshGraph();
mg.triangles = this.triangles;
foreach (MeshVertex v in vertices)
{
MeshVertex new_v = new MeshVertex(v.Position);
new_v.SetGraphInfo(mg, mg.vertices.Count);
mg.vertices.Add(new_v);
}
foreach (MeshEdge e in edges)
{
MeshEdge new_e = new MeshEdge(mg.Eqv(e.V1), mg.Eqv(e.V2));
new_e.SetGraphInfo(mg, mg.edges.Count);
mg.edges.Add(new_e);
}
foreach (MeshFacet f in facets)
{
MeshFacet new_f = new MeshFacet();
foreach (MeshVertex v in f.vertices)
{
new_f.vertices.Add(mg.Eqv(v));
}
new_f.SetGraphInfo(mg, mg.facets.Count);
mg.facets.Add(new_f);
}
// Maintain adjacency cache
foreach (MeshEdge e in mg.edges)
{
MeshEdge old_e = this.Eqv(e);
e.f1 = mg.Eqv(old_e.f1);
e.f2 = mg.Eqv(old_e.f2);
}
foreach (MeshVertex v in mg.vertices)
{
MeshVertex old_v = this.Eqv(v);
foreach (var entry in old_v.adjacency)
{
v.adjacency.Add(mg.Eqv(entry.Key), mg.Eqv(entry.Value));
}
}
return(mg);
}
public MeshFacet AddFacet(params MeshVertex[] vs)
{
if (vs.Length < 3)
{
throw new Exception("Vertex count less than 3.");
}
for (int vi = 0; vi < vs.Length; vi++)
{
if (vs[vi] == vs[(vi + 1) % vs.Length])
{
throw new Exception("Ill-formed vertex sequence");
}
}
MeshFacet f = new MeshFacet(vs);
string failure = "";
for (int vi = 0; vi < vs.Length; vi++)
{
MeshVertex p1 = vs[vi];
MeshVertex p2 = vs[(vi + 1) % vs.Length];
MeshEdge e = AddEdge(p1, p2);
if (e.V1 == p1 && e.V2 == p2)
{
if (e.f1 != null)
{
failure = "Positive facet has been occupied";
break;
}
e.f1 = f;
}
else if (e.V1 == p2 && e.V2 == p1)
{
if (e.f2 != null)
{
failure = "Negative facet has been occupied";
break;
}
e.f2 = f;
}
else
{
throw new Exception("Unexpected edge");
}
}
// rollback
if (failure.Length > 0)
{
foreach (MeshEdge e in f.Edges)
{
if (e == null)
{
continue;
}
if (e.f1 == f)
{
e.f1 = null;
}
if (e.f2 == f)
{
e.f2 = null;
}
}
throw new Exception(failure);
}
int i = facets.Count;
facets.Add(f);
f.SetGraphInfo(this, i);
triangles += f.TrianglesCount;
return(f);
}