2 * Copyright (C) 2009-2011 Andy Spencer <andy753421@gmail.com>
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * @short_description: Realtime Optimally-Adapting Meshes
22 * A spherical version of the Realtime Optimally-Adapting Meshes (ROAM)
23 * algorithm is use for drawing the surface of the planet. ROAM provide a
24 * continuous level-of-detail mesh of the planet which is used by #GritsOpenGL
25 * when drawing surface textures for GritsTiles.
27 * This implementation of the ROAM algorithm is based on an octahedron as the
37 #include "grits-util.h"
42 * - Optimize for memory consumption
43 * - Profile for computation speed
44 * - Target polygon count/detail
47 /* For GPQueue comparators */
48 static gint tri_cmp(RoamTriangle *a, RoamTriangle *b, gpointer data)
50 if (a->error < b->error) return 1;
51 else if (a->error > b->error) return -1;
54 static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data)
56 if (a->error < b->error) return -1;
57 else if (a->error > b->error) return 1;
67 * @lat: the latitude for the point
68 * @lon: the longitude for the point
69 * @elev: the elevation for the point
71 * Create a new point at the given locaiton
73 * Returns: the new point
75 RoamPoint *roam_point_new(gdouble lat, gdouble lon, gdouble elev)
77 RoamPoint *point = g_new0(RoamPoint, 1);
81 /* For get_intersect */
82 lle2xyz(lat, lon, elev, &point->x, &point->y, &point->z);
87 * roam_point_add_triangle:
89 * @triangle: the to add
91 * Associating a triangle with a point and update it's vertex normal.
93 void roam_point_add_triangle(RoamPoint *point, RoamTriangle *triangle)
95 for (int i = 0; i < 3; i++) {
96 point->norm[i] *= point->tris;
97 point->norm[i] += triangle->norm[i];
100 for (int i = 0; i < 3; i++)
101 point->norm[i] /= point->tris;
105 * roam_point_remove_triangle:
107 * @triangle: the to add
109 * Un-associating a triangle with a point and update it's vertex normal.
111 void roam_point_remove_triangle(RoamPoint *point, RoamTriangle *triangle)
113 for (int i = 0; i < 3; i++) {
114 point->norm[i] *= point->tris;
115 point->norm[i] -= triangle->norm[i];
119 for (int i = 0; i < 3; i++)
120 point->norm[i] /= point->tris;
124 * roam_point_update_height:
127 * Update the height (elevation) of a point based on the current height function
129 void roam_point_update_height(RoamPoint *point)
131 if (point->height_func) {
132 gdouble elev = point->height_func(
133 point->lat, point->lon, point->height_data);
134 lle2xyz(point->lat, point->lon, elev,
135 &point->x, &point->y, &point->z);
140 * roam_point_update_projection:
142 * @view: the view to use when projecting the point
144 * Updated the screen-space projection of a point.
146 void roam_point_update_projection(RoamPoint *point, RoamView *view)
148 static int count = 0;
149 static int version = 0;
150 if (version != view->version) {
151 g_debug("RoamPoint: Projected %d points", count);
153 version = view->version;
156 if (point->pversion != view->version) {
157 /* Cache projection */
158 gluProject(point->x, point->y, point->z,
159 view->model, view->proj, view->view,
160 &point->px, &point->py, &point->pz);
161 point->pversion = view->version;
172 * @m: the middle point
173 * @r: the right point
175 * Create a new triangle consisting of three points.
177 * Returns: the new triangle
179 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
182 RoamTriangle *triangle = g_new0(RoamTriangle, 1);
188 triangle->parent = parent;
189 triangle->split = roam_point_new(
191 (ABS(l->lat) == 90 ? r->lon :
192 ABS(r->lat) == 90 ? l->lon :
193 lon_avg(l->lon, r->lon)),
194 (l->elev + r->elev)/2);
195 /* TODO: Move this back to sphere, or actually use the nesting */
196 triangle->split->height_func = m->height_func;
197 triangle->split->height_data = m->height_data;
198 roam_point_update_height(triangle->split);
199 //if ((float)triangle->split->lat > 44 && (float)triangle->split->lat < 46)
200 // g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
201 // l->lat, m->lat, r->lat, triangle->split->lat);
202 //if ((float)l->lat == (float)r->lat &&
203 // (float)triangle->split->lat != (float)l->lat)
204 // g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
205 // triangle->split->lat, l->lat);
208 crossd3((gdouble*)triangle->p.l,
209 (gdouble*)triangle->p.m,
210 (gdouble*)triangle->p.r, triangle->norm);
211 normd(triangle->norm);
213 /* Store bounding box, for get_intersect */
214 RoamPoint *p[] = {l,m,r};
215 triangle->edge.n = -90; triangle->edge.s = 90;
216 triangle->edge.e = -180; triangle->edge.w = 180;
217 gboolean maxed = FALSE;
218 for (int i = 0; i < G_N_ELEMENTS(p); i++) {
219 triangle->edge.n = MAX(triangle->edge.n, p[i]->lat);
220 triangle->edge.s = MIN(triangle->edge.s, p[i]->lat);
221 if (p[i]->lat == 90 || p[i]->lat == -90)
223 if (p[i]->lon == 180) {
227 triangle->edge.e = MAX(triangle->edge.e, p[i]->lon);
228 triangle->edge.w = MIN(triangle->edge.w, p[i]->lon);
231 if (triangle->edge.e < 0)
232 triangle->edge.w = -180;
234 triangle->edge.e = 180;
237 //g_message("roam_triangle_new: %p", triangle);
242 * roam_triangle_free:
243 * @triangle: the triangle
245 * Free data associated with a triangle
247 void roam_triangle_free(RoamTriangle *triangle)
249 g_free(triangle->split);
255 * @triangle: the triangle
256 * @left: the left neighbor
257 * @base: the base neighbor
258 * @right: the right neighbor
259 * @sphere: the sphere to add the triangle to
261 * Add a triangle into the sphere's mesh using the given neighbors.
263 void roam_triangle_add(RoamTriangle *triangle,
264 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
267 triangle->t.l = left;
268 triangle->t.b = base;
269 triangle->t.r = right;
271 roam_point_add_triangle(triangle->p.l, triangle);
272 roam_point_add_triangle(triangle->p.m, triangle);
273 roam_point_add_triangle(triangle->p.r, triangle);
276 roam_triangle_update_errors(triangle, sphere);
278 triangle->handle = g_pqueue_push(sphere->triangles, triangle);
282 * roam_triangle_remove:
283 * @triangle: the triangle
284 * @sphere: the sphere to remove the triangle from
286 * Remove a triangle from a sphere's mesh.
288 void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
290 /* Update vertex normals */
291 roam_point_remove_triangle(triangle->p.l, triangle);
292 roam_point_remove_triangle(triangle->p.m, triangle);
293 roam_point_remove_triangle(triangle->p.r, triangle);
295 g_pqueue_remove(sphere->triangles, triangle->handle);
298 /* (neight->t.? == old) = new */
299 static void roam_triangle_sync_neighbors(RoamTriangle *neigh, RoamTriangle *old, RoamTriangle *new)
301 if (neigh->t.l == old) neigh->t.l = new;
302 else if (neigh->t.b == old) neigh->t.b = new;
303 else if (neigh->t.r == old) neigh->t.r = new;
306 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
308 RoamPoint *l = triangle->p.l;
309 RoamPoint *m = triangle->p.m;
310 RoamPoint *r = triangle->p.r;
311 gdouble min_x = MIN(MIN(l->px, m->px), r->px);
312 gdouble max_x = MAX(MAX(l->px, m->px), r->px);
313 gdouble min_y = MIN(MIN(l->py, m->py), r->py);
314 gdouble max_y = MAX(MAX(l->py, m->py), r->py);
315 gint *view = sphere->view->view;
316 return !(max_x < view[0] || min_x > view[2] ||
317 max_y < view[1] || min_y > view[3]) &&
318 l->pz > 0 && m->pz > 0 && r->pz > 0 &&
319 l->pz < 1 && m->pz < 1 && r->pz < 1;
322 static gboolean roam_triangle_backface(RoamTriangle *triangle, RoamSphere *sphere)
324 RoamPoint *l = triangle->p.l;
325 RoamPoint *m = triangle->p.m;
326 RoamPoint *r = triangle->p.r;
327 roam_point_update_projection(l, sphere->view);
328 roam_point_update_projection(m, sphere->view);
329 roam_point_update_projection(r, sphere->view);
330 double size = -( l->px * (m->py - r->py) +
331 m->px * (r->py - l->py) +
332 r->px * (l->py - m->py) ) / 2.0;
337 * roam_triangle_update_errors:
338 * @triangle: the triangle
339 * @sphere: the sphere to use when updating errors
341 * Update the error value associated with a triangle. Called when the view
344 void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
347 roam_point_update_projection(triangle->p.l, sphere->view);
348 roam_point_update_projection(triangle->p.m, sphere->view);
349 roam_point_update_projection(triangle->p.r, sphere->view);
351 if (!roam_triangle_visible(triangle, sphere)) {
352 triangle->error = -1;
354 roam_point_update_projection(triangle->split, sphere->view);
355 RoamPoint *l = triangle->p.l;
356 RoamPoint *m = triangle->p.m;
357 RoamPoint *r = triangle->p.r;
358 RoamPoint *split = triangle->split;
360 /* l-r midpoint projected l-r midpoint */
361 gdouble pxdist = (l->px + r->px)/2 - split->px;
362 gdouble pydist = (l->py + r->py)/2 - split->py;
364 triangle->error = sqrt(pxdist*pxdist + pydist*pydist);
366 /* Multiply by size of triangle */
367 double size = -( l->px * (m->py - r->py) +
368 m->px * (r->py - l->py) +
369 r->px * (l->py - m->py) ) / 2.0;
371 /* Size < 0 == backface */
372 triangle->error *= size;
374 /* Give some preference to "edge" faces */
375 if (roam_triangle_backface(triangle->t.l, sphere) ||
376 roam_triangle_backface(triangle->t.b, sphere) ||
377 roam_triangle_backface(triangle->t.r, sphere))
378 triangle->error *= 50;
383 * roam_triangle_split:
384 * @triangle: the triangle
385 * @sphere: the sphere
387 * Split a triangle into two child triangles and update the sphere.
390 void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
392 //g_message("roam_triangle_split: %p, e=%f\n", triangle, triangle->error);
396 if (triangle != triangle->t.b->t.b)
397 roam_triangle_split(triangle->t.b, sphere);
398 if (triangle != triangle->t.b->t.b)
399 g_assert_not_reached();
401 RoamTriangle *s = triangle; // Self
402 RoamTriangle *b = triangle->t.b; // Base
404 RoamDiamond *dia = roam_diamond_new(s, b);
406 /* Add new triangles */
407 RoamPoint *mid = triangle->split;
408 RoamTriangle *sl = s->kids[0] = roam_triangle_new(s->p.m, mid, s->p.l, dia); // Self Left
409 RoamTriangle *sr = s->kids[1] = roam_triangle_new(s->p.r, mid, s->p.m, dia); // Self Right
410 RoamTriangle *bl = b->kids[0] = roam_triangle_new(b->p.m, mid, b->p.l, dia); // Base Left
411 RoamTriangle *br = b->kids[1] = roam_triangle_new(b->p.r, mid, b->p.m, dia); // Base Right
413 /* triangle,l, base, r, sphere */
414 roam_triangle_add(sl, sr, s->t.l, br, sphere);
415 roam_triangle_add(sr, bl, s->t.r, sl, sphere);
416 roam_triangle_add(bl, br, b->t.l, sr, sphere);
417 roam_triangle_add(br, sl, b->t.r, bl, sphere);
419 roam_triangle_sync_neighbors(s->t.l, s, sl);
420 roam_triangle_sync_neighbors(s->t.r, s, sr);
421 roam_triangle_sync_neighbors(b->t.l, b, bl);
422 roam_triangle_sync_neighbors(b->t.r, b, br);
424 /* Remove old triangles */
425 roam_triangle_remove(s, sphere);
426 roam_triangle_remove(b, sphere);
428 /* Add/Remove diamonds */
429 roam_diamond_update_errors(dia, sphere);
430 roam_diamond_add(dia, sphere);
431 roam_diamond_remove(s->parent, sphere);
432 roam_diamond_remove(b->parent, sphere);
436 * roam_triangle_draw:
437 * @triangle: the triangle
439 * Draw the triangle. Use for debugging.
441 void roam_triangle_draw(RoamTriangle *triangle)
443 glBegin(GL_TRIANGLES);
444 glNormal3dv(triangle->p.r->norm); glVertex3dv((double*)triangle->p.r);
445 glNormal3dv(triangle->p.m->norm); glVertex3dv((double*)triangle->p.m);
446 glNormal3dv(triangle->p.l->norm); glVertex3dv((double*)triangle->p.l);
452 * roam_triangle_draw_normal:
453 * @triangle: the triangle
455 * Draw a normal vector for the triangle. Used while debugging.
457 void roam_triangle_draw_normal(RoamTriangle *triangle)
460 (triangle->p.l->x + triangle->p.m->x + triangle->p.r->x)/3.0,
461 (triangle->p.l->y + triangle->p.m->y + triangle->p.r->y)/3.0,
462 (triangle->p.l->z + triangle->p.m->z + triangle->p.r->z)/3.0,
465 center[0]+triangle->norm[0]*2000000,
466 center[1]+triangle->norm[1]*2000000,
467 center[2]+triangle->norm[2]*2000000,
480 * @parent0: a parent triangle
481 * @parent1: a parent triangle
482 * @kid0: a child triangle
483 * @kid1: a child triangle
484 * @kid2: a child triangle
485 * @kid3: a child triangle
487 * Create a diamond to store information about two split triangles.
489 * Returns: the new diamond
491 RoamDiamond *roam_diamond_new(RoamTriangle *parent0, RoamTriangle *parent1)
493 RoamDiamond *diamond = g_new0(RoamDiamond, 1);
494 diamond->parents[0] = parent0;
495 diamond->parents[1] = parent1;
501 * @diamond: the diamond
502 * @sphere: the sphere to add the diamond to
504 * Add a diamond into the sphere's pool of diamonds. It will be check for
507 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere)
509 diamond->active = TRUE;
510 diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
511 diamond->handle = g_pqueue_push(sphere->diamonds, diamond);
515 * roam_diamond_remove:
516 * @diamond: the diamond
517 * @sphere: the sphere to remove the diamond from
519 * Remove a diamond from the sphere's pool of diamonds.
521 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere)
523 if (diamond && diamond->active) {
524 diamond->active = FALSE;
525 g_pqueue_remove(sphere->diamonds, diamond->handle);
530 * roam_diamond_merge:
531 * @diamond: the diamond
532 * @sphere: the sphere
534 * "Merge" a diamond back into two parent triangles. The original two triangles
535 * are added back into the sphere and the four child triangles as well as the
536 * diamond are removed.
538 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
540 //g_message("roam_diamond_merge: %p, e=%f\n", diamond, diamond->error);
542 /* TODO: pick the best split */
545 /* Use nicer temp names */
546 RoamTriangle *s = diamond->parents[0]; // Self
547 RoamTriangle *b = diamond->parents[1]; // Base
549 RoamTriangle *sl = s->kids[0];
550 RoamTriangle *sr = s->kids[1];
551 RoamTriangle *bl = b->kids[0];
552 RoamTriangle *br = b->kids[1];
554 s->kids[0] = s->kids[1] = NULL;
555 b->kids[0] = b->kids[1] = NULL;
557 /* Add original triangles */
558 roam_triangle_sync_neighbors(s->t.l, sl, s);
559 roam_triangle_sync_neighbors(s->t.r, sr, s);
560 roam_triangle_sync_neighbors(b->t.l, bl, b);
561 roam_triangle_sync_neighbors(b->t.r, br, b);
563 roam_triangle_add(s, sl->t.b, b, sr->t.b, sphere);
564 roam_triangle_add(b, bl->t.b, s, br->t.b, sphere);
566 roam_triangle_sync_neighbors(sl->t.b, sl, s);
567 roam_triangle_sync_neighbors(sr->t.b, sr, s);
568 roam_triangle_sync_neighbors(bl->t.b, bl, b);
569 roam_triangle_sync_neighbors(br->t.b, br, b);
571 /* Remove child triangles */
572 roam_triangle_remove(sl, sphere);
573 roam_triangle_remove(sr, sphere);
574 roam_triangle_remove(bl, sphere);
575 roam_triangle_remove(br, sphere);
577 /* Add/Remove triangles */
578 if (s->t.l->t.l == s->t.r->t.r &&
579 s->t.l->t.l != s && s->parent) {
580 roam_diamond_update_errors(s->parent, sphere);
581 roam_diamond_add(s->parent, sphere);
584 if (b->t.l->t.l == b->t.r->t.r &&
585 b->t.l->t.l != b && b->parent) {
586 roam_diamond_update_errors(b->parent, sphere);
587 roam_diamond_add(b->parent, sphere);
590 /* Remove and free diamond and child triangles */
591 roam_diamond_remove(diamond, sphere);
592 g_assert(sl->p.m == sr->p.m &&
593 sr->p.m == bl->p.m &&
595 g_assert(sl->p.m->tris == 0);
596 roam_triangle_free(sl);
597 roam_triangle_free(sr);
598 roam_triangle_free(bl);
599 roam_triangle_free(br);
604 * roam_diamond_update_errors:
605 * @diamond: the diamond
606 * @sphere: the sphere to use when updating errors
608 * Update the error value associated with a diamond. Called when the view
611 void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere)
613 roam_triangle_update_errors(diamond->parents[0], sphere);
614 roam_triangle_update_errors(diamond->parents[1], sphere);
615 diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
624 * Create a new sphere
626 * Returns: the sphere
628 RoamSphere *roam_sphere_new()
630 RoamSphere *sphere = g_new0(RoamSphere, 1);
632 sphere->triangles = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
633 sphere->diamonds = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
635 RoamPoint *vertexes[] = {
636 roam_point_new( 90, 0, 0), // 0 (North)
637 roam_point_new(-90, 0, 0), // 1 (South)
638 roam_point_new( 0, 0, 0), // 2 (Europe/Africa)
639 roam_point_new( 0, 90, 0), // 3 (Asia,East)
640 roam_point_new( 0, 180, 0), // 4 (Pacific)
641 roam_point_new( 0, -90, 0), // 5 (Americas,West)
643 int _triangles[][2][3] = {
644 /*lv mv rv ln, bn, rn */
645 {{2,0,3}, {3, 4, 1}}, // 0
646 {{3,0,4}, {0, 5, 2}}, // 1
647 {{4,0,5}, {1, 6, 3}}, // 2
648 {{5,0,2}, {2, 7, 0}}, // 3
649 {{3,1,2}, {5, 0, 7}}, // 4
650 {{4,1,3}, {6, 1, 4}}, // 5
651 {{5,1,4}, {7, 2, 5}}, // 6
652 {{2,1,5}, {4, 3, 6}}, // 7
655 for (int i = 0; i < 6; i++)
656 roam_point_update_height(vertexes[i]);
657 for (int i = 0; i < 8; i++)
658 sphere->roots[i] = roam_triangle_new(
659 vertexes[_triangles[i][0][0]],
660 vertexes[_triangles[i][0][1]],
661 vertexes[_triangles[i][0][2]],
663 for (int i = 0; i < 8; i++)
664 roam_triangle_add(sphere->roots[i],
665 sphere->roots[_triangles[i][1][0]],
666 sphere->roots[_triangles[i][1][1]],
667 sphere->roots[_triangles[i][1][2]],
669 for (int i = 0; i < 8; i++)
670 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", sphere->roots[i],
671 sphere->roots[i]->edge.n,
672 sphere->roots[i]->edge.s,
673 sphere->roots[i]->edge.e,
674 sphere->roots[i]->edge.w);
680 * roam_sphere_update_view
681 * @sphere: the sphere
683 * Recreate the sphere's view matrices based on the current OpenGL state.
685 void roam_sphere_update_view(RoamSphere *sphere)
688 sphere->view = g_new0(RoamView, 1);
689 glGetDoublev (GL_MODELVIEW_MATRIX, sphere->view->model);
690 glGetDoublev (GL_PROJECTION_MATRIX, sphere->view->proj);
691 glGetIntegerv(GL_VIEWPORT, sphere->view->view);
692 sphere->view->version++;
696 * roam_sphere_update_errors
697 * @sphere: the sphere
699 * Update triangle and diamond errors in the sphere.
701 void roam_sphere_update_errors(RoamSphere *sphere)
703 g_debug("RoamSphere: update_errors - polys=%d", sphere->polys);
704 GPtrArray *tris = g_pqueue_get_array(sphere->triangles);
705 GPtrArray *dias = g_pqueue_get_array(sphere->diamonds);
707 roam_sphere_update_view(sphere);
709 for (int i = 0; i < tris->len; i++) {
710 RoamTriangle *triangle = tris->pdata[i];
711 roam_triangle_update_errors(triangle, sphere);
712 g_pqueue_priority_changed(sphere->triangles, triangle->handle);
715 for (int i = 0; i < dias->len; i++) {
716 RoamDiamond *diamond = dias->pdata[i];
717 roam_diamond_update_errors(diamond, sphere);
718 g_pqueue_priority_changed(sphere->diamonds, diamond->handle);
721 g_ptr_array_free(tris, TRUE);
722 g_ptr_array_free(dias, TRUE);
726 * roam_sphere_split_one
727 * @sphere: the sphere
729 * Split the triangle with the greatest error.
731 void roam_sphere_split_one(RoamSphere *sphere)
733 RoamTriangle *to_split = g_pqueue_peek(sphere->triangles);
734 if (!to_split) return;
735 roam_triangle_split(to_split, sphere);
739 * roam_sphere_merge_one
740 * @sphere: the sphere
742 * Merge the diamond with the lowest error.
744 void roam_sphere_merge_one(RoamSphere *sphere)
746 RoamDiamond *to_merge = g_pqueue_peek(sphere->diamonds);
747 if (!to_merge) return;
748 roam_diamond_merge(to_merge, sphere);
752 * roam_sphere_split_merge
753 * @sphere: the sphere
755 * Perform a predetermined number split-merge iterations.
757 * Returns: the number splits and merges done
759 gint roam_sphere_split_merge(RoamSphere *sphere)
761 gint iters = 0, max_iters = 500;
762 //gint target = 20000;
763 //gint target = 4000;
770 if (target - sphere->polys > 100) {
771 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, sphere->polys);
772 while (sphere->polys < target && iters++ < max_iters)
773 roam_sphere_split_one(sphere);
776 if (sphere->polys - target > 100) {
777 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", sphere->polys, target);
778 while (sphere->polys > target && iters++ < max_iters)
779 roam_sphere_merge_one(sphere);
782 while (((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error >
783 ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error &&
784 iters++ < max_iters) {
785 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
786 // ((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error,
787 // ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error,
788 // iters-1, max_iters);
789 roam_sphere_merge_one(sphere);
790 roam_sphere_split_one(sphere);
798 * @sphere: the sphere
800 * Draw the sphere. Use for debugging.
802 void roam_sphere_draw(RoamSphere *sphere)
804 g_debug("RoamSphere: draw");
805 g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw, NULL);
809 * roam_sphere_draw_normals
810 * @sphere: the sphere
812 * Draw all the surface normal vectors for the sphere. Used while debugging.
814 void roam_sphere_draw_normals(RoamSphere *sphere)
816 g_debug("RoamSphere: draw_normal");
817 g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw_normal, NULL);
820 static GList *_roam_sphere_get_leaves(RoamTriangle *triangle, GList *list, gboolean all)
822 if (triangle->kids[0] && triangle->kids[1]) {
823 if (all) list = g_list_prepend(list, triangle);
824 list = _roam_sphere_get_leaves(triangle->kids[0], list, all);
825 list = _roam_sphere_get_leaves(triangle->kids[1], list, all);
828 return g_list_prepend(list, triangle);
832 static GList *_roam_sphere_get_intersect_rec(RoamTriangle *triangle, GList *list,
833 gboolean all, gdouble n, gdouble s, gdouble e, gdouble w)
835 gdouble tn = triangle->edge.n;
836 gdouble ts = triangle->edge.s;
837 gdouble te = triangle->edge.e;
838 gdouble tw = triangle->edge.w;
840 gboolean debug = FALSE &&
841 n==90 && s==45 && e==-90 && w==-180 &&
845 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
846 triangle, tn, s, ts, n, te, w, tw, e);
847 if (tn <= s || ts >= n || te <= w || tw >= e) {
849 if (debug) g_message("no intersect");
851 } else if (tn <= n && ts >= s && te <= e && tw >= w) {
852 /* Triangle is completely contained */
853 if (debug) g_message("contained");
854 if (all) list = g_list_prepend(list, triangle);
855 return _roam_sphere_get_leaves(triangle, list, all);
856 } else if (triangle->kids[0] && triangle->kids[1]) {
857 /* Paritial intersect with children */
858 if (debug) g_message("edge w/ child");
859 if (all) list = g_list_prepend(list, triangle);
860 list = _roam_sphere_get_intersect_rec(triangle->kids[0], list, all, n, s, e, w);
861 list = _roam_sphere_get_intersect_rec(triangle->kids[1], list, all, n, s, e, w);
864 /* This triangle is an edge case */
865 if (debug) g_message("edge");
866 return g_list_prepend(list, triangle);
871 * roam_sphere_get_intersect
872 * @sphere: the sphere
873 * @all: TRUE if non-leaf triangle should be returned as well
874 * @n: the northern edge
875 * @s: the southern edge
876 * @e: the eastern edge
877 * @w: the western edge
879 * Lookup triangles withing the sphere that intersect a given lat-lon box.
881 * Returns: the list of intersecting triangles.
883 /* Warning: This grabs pointers to triangles which can be changed by other
884 * calls, e.g. split_merge. If you use this, you need to do some locking to
885 * prevent the returned list from becomming stale. */
886 GList *roam_sphere_get_intersect(RoamSphere *sphere, gboolean all,
887 gdouble n, gdouble s, gdouble e, gdouble w)
889 /* I think this is correct..
890 * i_cost = cost for triangle-rectagnle intersect test
891 * time = n_tiles * 2*tris_per_tile * i_cost
892 * time = 30 * 2*333 * i_cost = 20000 * i_cost */
894 for (int i = 0; i < G_N_ELEMENTS(sphere->roots); i++)
895 list = _roam_sphere_get_intersect_rec(sphere->roots[i],
896 list, all, n, s, e, w);
900 static void roam_sphere_free_tri(RoamTriangle *triangle)
902 if (--triangle->p.l->tris == 0) g_free(triangle->p.l);
903 if (--triangle->p.m->tris == 0) g_free(triangle->p.m);
904 if (--triangle->p.r->tris == 0) g_free(triangle->p.r);
905 roam_triangle_free(triangle);
910 * @sphere: the sphere
912 * Free data associated with a sphere
914 void roam_sphere_free(RoamSphere *sphere)
916 g_debug("RoamSphere: free");
917 /* Slow method, but it should work */
918 while (sphere->polys > 8)
919 roam_sphere_merge_one(sphere);
920 /* TODO: free points */
921 g_pqueue_foreach(sphere->triangles, (GFunc)roam_sphere_free_tri, NULL);
922 g_pqueue_free(sphere->triangles);
923 g_pqueue_free(sphere->diamonds);
924 g_free(sphere->view);