v_data *delaunay_triangulation(double *x, double *y, int n)
{
v_data *delaunay;
GtsSurface* s = tri(x, y, n, NULL, 0, 1);
int i, nedges;
int* edges;
estats stats;
if (!s) return NULL;
delaunay = N_GNEW(n, v_data);
for (i = 0; i < n; i++) {
delaunay[i].ewgts = NULL;
delaunay[i].nedges = 1;
}
stats.n = 0;
stats.delaunay = delaunay;
edgeStats (s, &stats);
nedges = stats.n;
edges = N_GNEW(2 * nedges + n, int);
for (i = 0; i < n; i++) {
delaunay[i].edges = edges;
edges += delaunay[i].nedges;
delaunay[i].edges[0] = i;
delaunay[i].nedges = 1;
}
gts_surface_foreach_edge (s, (GtsFunc) add_edge, delaunay);
gts_object_destroy (GTS_OBJECT (s));
return delaunay;
}
/* delaunay_tri:
* Given n points whose coordinates are in the x[] and y[]
* arrays, compute a Delaunay triangulation of the points.
* The number of edges in the triangulation is returned in pnedges.
* The return value itself is an array e of 2*(*pnedges) integers,
* with edge i having points whose indices are e[2*i] and e[2*i+1].
*
* If the points are collinear, GTS fails with 0 edges.
* In this case, we sort the points by x coordinates (or y coordinates
* if the points form a vertical line). We then return a "triangulation"
* consisting of the n-1 pairs of adjacent points.
*/
int *delaunay_tri(double *x, double *y, int n, int* pnedges)
{
GtsSurface* s = tri(x, y, n, NULL, 0, 1);
int nedges;
int* edges;
estats stats;
estate state;
if (!s) return NULL;
stats.n = 0;
stats.delaunay = NULL;
edgeStats (s, &stats);
*pnedges = nedges = stats.n;
if (nedges) {
edges = N_GNEW(2 * nedges, int);
state.n = 0;
state.edges = edges;
gts_surface_foreach_edge (s, (GtsFunc) addEdge, &state);
}
else {
/**
* gts_bb_tree_surface_boundary_distance:
* @tree: a bounding box tree.
* @s: a #GtsSurface.
* @distance: a #GtsBBoxDistFunc.
* @delta: a sampling increment defined as the percentage of the diagonal
* of the root bounding box of @tree.
* @range: a #GtsRange to be filled with the results.
*
* Calls gts_bb_tree_segment_distance() for each edge boundary of @s.
* The fields of @range are filled with the minimum, maximum and
* average distance. The average distance is defined as the sum of the
* average distances for each boundary edge weighthed by their length
* and divided by the total length of the boundaries. The standard
* deviation is defined accordingly. The @n field of @range is filled
* with the number of sampled points used.
*/
void gts_bb_tree_surface_boundary_distance (GNode * tree,
GtsSurface * s,
gdouble (*distance) (GtsPoint *,
gpointer),
gdouble delta,
GtsRange * range)
{
gpointer data[5];
gdouble total_length = 0.;
g_return_if_fail (tree != NULL);
g_return_if_fail (s != NULL);
g_return_if_fail (delta > 0. && delta < 1.);
g_return_if_fail (range != NULL);
gts_range_init (range);
delta *= sqrt (gts_bbox_diagonal2 (tree->data));
data[0] = tree;
data[1] = δ
data[2] = range;
data[3] = &total_length;
data[4] = distance;
gts_surface_foreach_edge (s,
(GtsFunc) surface_distance_foreach_boundary,
data);
if (total_length > 0.) {
if (range->sum2 - range->sum*range->sum/total_length >= 0.)
range->stddev = sqrt ((range->sum2 -
range->sum*range->sum/total_length)
/total_length);
else
range->stddev = 0.;
range->mean = range->sum/total_length;
}
else
range->min = range->max = range->mean = range->stddev = 0.;
}
static void surface_optimize (GtsSurface * surface,
gdouble max_cost)
{
GtsEHeap * heap;
GtsEdge * e;
gdouble top_cost;
heap = gts_eheap_new ((GtsKeyFunc) edge_swap_cost, NULL);
gts_eheap_freeze (heap);
gts_surface_foreach_edge (surface, (GtsFunc) create_heap_optimize, heap);
gts_eheap_thaw (heap);
gts_allow_floating_edges = TRUE;
while ((e = gts_eheap_remove_top (heap, &top_cost)) &&
top_cost < max_cost)
edge_swap (e, surface, heap);
gts_allow_floating_edges = FALSE;
if (e) GTS_OBJECT (e)->reserved = NULL;
gts_eheap_foreach (heap, (GFunc) gts_object_reset_reserved, NULL);
gts_eheap_destroy (heap);
}
int main (int argc, char * argv[])
{
GtsSurface * s;
guint i;
GtsFile * fp;
guint nv = 1, ne = 1, nf = 1;
if (!setlocale (LC_ALL, "POSIX"))
g_warning ("cannot set locale to POSIX");
s = gts_surface_new (gts_surface_class (),
gts_face_class (),
gts_edge_class (),
gts_vertex_class ());
fp = gts_file_new (stdin);
if (gts_surface_read (s, fp)) {
fputs ("gtstoc: file on standard input is not a valid GTS file\n",
stderr);
fprintf (stderr, "stdin:%d:%d: %s\n", fp->line, fp->pos, fp->error);
return 1; /* failure */
}
printf (" GtsSurface * surface = gts_surface_new (gts_surface_class (),\n"
" gts_face_class (),\n"
" gts_edge_class (),\n"
" gts_vertex_class ());\n\n");
gts_surface_foreach_vertex (s, (GtsFunc) write_vertex, &nv);
printf ("\n");
gts_surface_foreach_edge (s, (GtsFunc) write_edge, &ne);
printf ("\n");
gts_surface_foreach_face (s, (GtsFunc) write_face, &nf);
printf (" \n");
for (i = 1; i < nf; i++)
printf (" gts_surface_add_face (surface, f%u);\n", i);
return 0;
}
void
pygts_edge_cleanup(GtsSurface *s)
{
GSList *edges = NULL;
GSList *i, *ii, *cur, *parents=NULL;
PygtsEdge *edge;
GtsEdge *e, *duplicate;
g_return_if_fail(s != NULL);
/* build list of edges */
gts_surface_foreach_edge(s, (GtsFunc)build_list, &edges);
/* remove degenerate and duplicate edges.
Note: we could use gts_edges_merge() to remove the duplicates and then
remove the degenerate edges but it is more efficient to do everything
at once (and it's more pedagogical too ...) */
/* We want to control manually the destruction of edges */
gts_allow_floating_edges = TRUE;
i = edges;
while(i) {
e = (GtsEdge*)i->data;
if(GTS_SEGMENT(e)->v1 == GTS_SEGMENT(e)->v2) {
/* edge is degenerate */
if( !g_hash_table_lookup(obj_table,GTS_OBJECT(e)) ) {
/* destroy e */
gts_object_destroy(GTS_OBJECT(e));
}
}
else {
if((duplicate = gts_edge_is_duplicate(e))) {
/* Detach and save any parent triangles */
if( (edge = PYGTS_EDGE(g_hash_table_lookup(obj_table,GTS_OBJECT(e))))
!=NULL ) {
ii = e->triangles;
while(ii!=NULL) {
cur = ii;
ii = g_slist_next(ii);
if(PYGTS_IS_PARENT_TRIANGLE(cur->data)) {
e->triangles = g_slist_remove_link(e->triangles, cur);
parents = g_slist_prepend(parents,cur->data);
g_slist_free_1(cur);
}
}
}
/* replace e with its duplicate */
gts_edge_replace(e, duplicate);
/* Reattach the parent segments */
if( edge != NULL ) {
ii = parents;
while(ii!=NULL) {
e->triangles = g_slist_prepend(e->triangles, ii->data);
ii = g_slist_next(ii);
}
g_slist_free(parents);
parents = NULL;
}
if( !g_hash_table_lookup(obj_table,GTS_OBJECT(e)) ) {
/* destroy e */
gts_object_destroy(GTS_OBJECT (e));
}
}
}
i = g_slist_next(i);
}
/* don't forget to reset to default */
gts_allow_floating_edges = FALSE;
/* free list of edges */
g_slist_free (edges);
}
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 void
edgeStats (GtsSurface* s, estats* sp)
{
gts_surface_foreach_edge (s, (GtsFunc) cnt_edge, sp);
}
int main (int argc, char * argv[])
{
GtsSurface * s;
gboolean verbose = FALSE;
gdouble threshold;
int c = 0;
GtsFile * fp;
GtsRange angle;
if (!setlocale (LC_ALL, "POSIX"))
g_warning ("cannot set locale to POSIX");
/* parse options using getopt */
while (c != EOF) {
#ifdef HAVE_GETOPT_LONG
static struct option long_options[] = {
{"help", no_argument, NULL, 'h'},
{"verbose", no_argument, NULL, 'v'},
{ NULL }
};
int option_index = 0;
switch ((c = getopt_long (argc, argv, "hv",
long_options, &option_index))) {
#else /* not HAVE_GETOPT_LONG */
switch ((c = getopt (argc, argv, "hv"))) {
#endif /* not HAVE_GETOPT_LONG */
case 'v': /* verbose */
verbose = TRUE;
break;
case 'h': /* help */
fprintf (stderr,
"Usage: optimize [OPTION] THRESHOLD < FILE\n"
"\n"
" -v --verbose print statistics about the surface\n"
" -h --help display this help and exit\n"
"\n"
"Report bugs to %s\n",
GTS_MAINTAINER);
return 0; /* success */
break;
case '?': /* wrong options */
fprintf (stderr, "Try `optimize --help' for more information.\n");
return 1; /* failure */
}
}
if (optind >= argc) { /* missing threshold */
fprintf (stderr,
"optimize: missing THRESHOLD\n"
"Try `optimize --help' for more information.\n");
return 1; /* failure */
}
threshold = strtod (argv[optind], NULL);
if (threshold < 0.0) { /* threshold must be positive */
fprintf (stderr,
"optimize: THRESHOLD must be >= 0.0\n"
"Try `optimize --help' for more information.\n");
return 1; /* failure */
}
/* read surface in */
s = gts_surface_new (gts_surface_class (),
gts_face_class (),
gts_edge_class (),
gts_vertex_class ());
fp = gts_file_new (stdin);
if (gts_surface_read (s, fp)) {
fputs ("optimize: file on standard input is not a valid GTS file\n",
stderr);
fprintf (stderr, "stdin:%d:%d: %s\n", fp->line, fp->pos, fp->error);
return 1; /* failure */
}
/* if verbose on print stats */
if (verbose) {
gts_surface_print_stats (s, stderr);
gts_range_init (&angle);
gts_surface_foreach_edge (s, (GtsFunc) angle_stats, &angle);
gts_range_update (&angle);
fputs ("# angle : ", stderr);
gts_range_print (&angle, stderr);
fputc ('\n', stderr);
}
surface_optimize (s, -threshold);
/* if verbose on print stats */
if (verbose) {
gts_surface_print_stats (s, stderr);
gts_range_init (&angle);
gts_surface_foreach_edge (s, (GtsFunc) angle_stats, &angle);
gts_range_update (&angle);
fputs ("# angle : ", stderr);
gts_range_print (&angle, stderr);
fputc ('\n', stderr);
}
/* write surface */
gts_surface_write (s, stdout);
return 0; /* success */
}
