/**
* gts_edge_swap:
* @e: a #GtsEdge.
* @s: a #GtsSurface.
*
* Performs an "edge swap" on the two triangles sharing @e and
* belonging to @s.
*/
void gts_edge_swap (GtsEdge * e, GtsSurface * s)
{
GtsTriangle * t1 = NULL, * t2 = NULL, * t;
GtsFace * f;
GSList * i;
GtsVertex * v1, * v2, * v3, * v4, * v5, * v6;
GtsEdge * e1, * e2, * e3, * e4;
GtsSegment * v3v6;
g_return_if_fail (e != NULL);
g_return_if_fail (s != NULL);
i = e->triangles;
while (i) {
if (GTS_IS_FACE (i->data) && gts_face_has_parent_surface (i->data, s)) {
if (!t1)
t1 = i->data;
else if (!t2)
t2 = i->data;
else
g_return_if_fail (gts_edge_face_number (e, s) == 2);
}
i = i->next;
}
g_assert (t1 && t2);
gts_triangle_vertices_edges (t1, e, &v1, &v2, &v3, &e, &e1, &e2);
gts_triangle_vertices_edges (t2, e, &v4, &v5, &v6, &e, &e3, &e4);
g_assert (v2 == v4 && v1 == v5);
v3v6 = gts_vertices_are_connected (v3, v6);
if (!GTS_IS_EDGE (v3v6))
v3v6 = GTS_SEGMENT (gts_edge_new (s->edge_class, v3, v6));
f = gts_face_new (s->face_class, e1, GTS_EDGE (v3v6), e4);
if ((t = gts_triangle_is_duplicate (GTS_TRIANGLE (f))) &&
GTS_IS_FACE (t)) {
gts_object_destroy (GTS_OBJECT (f));
f = GTS_FACE (t);
}
gts_surface_add_face (s, f);
f = gts_face_new (s->face_class, GTS_EDGE (v3v6), e2, e3);
if ((t = gts_triangle_is_duplicate (GTS_TRIANGLE (f))) &&
GTS_IS_FACE (t)) {
gts_object_destroy (GTS_OBJECT (f));
f = GTS_FACE (t);
}
gts_surface_add_face (s, f);
gts_surface_remove_face (s, GTS_FACE (t1));
gts_surface_remove_face (s, GTS_FACE (t2));
}
void
pygts_face_cleanup(GtsSurface * s)
{
GSList *triangles = NULL;
GSList * i;
g_return_if_fail(s != NULL);
/* build list of triangles */
gts_surface_foreach_face(s, (GtsFunc) build_list, &triangles);
/* remove duplicate and degenerate triangles */
i = triangles;
while(i) {
GtsTriangle * t = (GtsTriangle*)i->data;
if (!gts_triangle_is_ok(t)) {
/* destroy t, its edges (if not used by any other triangle)
and its corners (if not used by any other edge) */
if( g_hash_table_lookup(obj_table,GTS_OBJECT(t))==NULL ) {
gts_object_destroy(GTS_OBJECT(t));
}
else {
gts_surface_remove_face(PYGTS_SURFACE_AS_GTS_SURFACE(s),GTS_FACE(t));
}
}
i = g_slist_next(i);
}
/* free list of triangles */
g_slist_free(triangles);
}
