static guint delaunay_remove_holes (GtsSurface * surface)
{
g_return_val_if_fail (surface != NULL, 0);
return gts_surface_foreach_face_remove (surface,
(GtsFunc) triangle_is_hole, NULL);
}
static GtsSurface * cartesian_grid_triangulate_holes (CartesianGrid * grid,
GtsSurface * s)
{
GtsVertex * v1, * v2, * v3, * v4;
GtsEdge * e1, * e2, * e3, * e4, * e5;
gdouble w, h;
GtsSurface * box;
GSList * constraints = NULL, * vertices = NULL, * i;
gpointer data[2];
g_return_val_if_fail (grid != NULL, NULL);
g_return_val_if_fail (s != NULL, NULL);
/* build enclosing box */
w = grid->xmax - grid->xmin;
h = grid->ymax - grid->ymin;
v1 = gts_vertex_new (s->vertex_class, grid->xmin - w, grid->ymin - h, 0.);
v2 = gts_vertex_new (s->vertex_class, grid->xmax + w, grid->ymin - h, 0.);
v3 = gts_vertex_new (s->vertex_class, grid->xmax + w, grid->ymax + h, 0.);
v4 = gts_vertex_new (s->vertex_class, grid->xmin - w, grid->ymax + h, 0.);
e1 = gts_edge_new (s->edge_class, v1, v2);
e2 = gts_edge_new (s->edge_class, v2, v3);
e3 = gts_edge_new (s->edge_class, v3, v4);
e4 = gts_edge_new (s->edge_class, v4, v1);
e5 = gts_edge_new (s->edge_class, v1, v3);
box = gts_surface_new (GTS_SURFACE_CLASS (GTS_OBJECT (s)->klass),
s->face_class,
s->edge_class,
s->vertex_class);
gts_surface_add_face (box, gts_face_new (s->face_class, e1, e2, e5));
gts_surface_add_face (box, gts_face_new (s->face_class, e3, e4, e5));
/* build vertex and constraint list from the boundaries of the input
surface s */
data[0] = s;
data[1] = &constraints;
gts_surface_foreach_edge (s, (GtsFunc) build_constraint_list, data);
vertices = gts_vertices_from_segments (constraints);
/* triangulate holes */
i = vertices;
while (i) {
g_assert (!gts_delaunay_add_vertex (box, i->data, NULL));
i = i->next;
}
g_slist_free (vertices);
i = constraints;
while (i) {
g_assert (!gts_delaunay_add_constraint (box, i->data));
i = i->next;
}
/* destroy corners of the enclosing box */
gts_allow_floating_vertices = TRUE;
gts_object_destroy (GTS_OBJECT (v1));
gts_object_destroy (GTS_OBJECT (v2));
gts_object_destroy (GTS_OBJECT (v3));
gts_object_destroy (GTS_OBJECT (v4));
gts_allow_floating_vertices = FALSE;
/* remove parts of the mesh which are not holes */
i = constraints;
while (i) {
edge_mark_as_hole (i->data, box);
i = i->next;
}
g_slist_free (constraints);
/* remove marked and duplicate faces */
gts_surface_foreach_face_remove (box, (GtsFunc) face_is_marked, NULL);
/* box now contains only the triangulated holes. */
return box;
}
static guint delaunay_remove_holes(GtsSurface * surface)
{
return gts_surface_foreach_face_remove(surface,
(GtsFunc) triangle_is_hole, NULL);
}
