int
Bedge::redefine(Bvert *v, Bvert *u)
{
// redefine this edge, replacing v with u
// precondition:
// edge does not already contain u.
// v is a vertex of this edge.
// faces have already been detached.
// can't duplicate an existing edge.
assert(contains(v) && nfaces() == 0);
if (contains(u))
return 0;
Bedge* dup = 0;
if (v == _v1) {
if ((dup = u->lookup_edge(_v2))) {
// can't redefine, but if this is a crease edge
// should ensure the duplicated edge is also
if (is_crease())
dup->set_crease(crease_val());
return 0;
}
// can redefine:
*_v1 -= this; // say bye to old _v1
_v1 = u; // record new _v1
*_v1 += this; // say hi to new _v1
} else if (v == _v2) {
// see comments above
if ((dup = u->lookup_edge(_v1))) {
if (is_crease())
dup->set_crease(crease_val());
return 0;
}
*_v2 -= this;
_v2 = u;
*_v2 += this;
} else assert(0);
geometry_changed();
return 1;
}
