void EdgeMesh::Face::Bridge(Edge& e0, Edge& e1)
{
assert(IsValid());
assert(e0.face == this && e1.face != this);
AdoptEdgeLoop(e1);
e0.BridgeTo(e1);
assert(IsValid());
}
EdgeMesh::FacePtr EdgeMesh::Face::Split(Edge& e0, Edge& e1)
{
assert(IsValid());
assert(e0.face == this && e1.face == this);
FacePtr newFace = std::make_unique<Face>();
e0.BridgeTo(e1); // e0 loop now separate.
newFace->AdoptEdgeLoop(e0);
assert(IsValid());
assert(newFace->IsValid());
return newFace;
}