2 * Copyright (C) 2009-2010 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
38 #include "grits-util.h"
43 * - Optimize for memory consumption
44 * - Profile for computation speed
45 * - Target polygon count/detail
48 /* For GPQueue comparators */
49 static gint tri_cmp(RoamTriangle *a, RoamTriangle *b, gpointer data)
51 if (a->error < b->error) return 1;
52 else if (a->error > b->error) return -1;
55 static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data)
57 if (a->error < b->error) return -1;
58 else if (a->error > b->error) return 1;
68 * @lat: the latitude for the point
69 * @lon: the longitude for the point
70 * @elev: the elevation for the point
72 * Create a new point at the given locaiton
74 * Returns: the new point
76 RoamPoint *roam_point_new(gdouble lat, gdouble lon, gdouble elev)
78 RoamPoint *point = g_new0(RoamPoint, 1);
82 /* For get_intersect */
83 lle2xyz(lat, lon, elev, &point->x, &point->y, &point->z);
88 * roam_point_add_triangle:
90 * @triangle: the to add
92 * Associating a triangle with a point and update it's vertex normal.
94 void roam_point_add_triangle(RoamPoint *point, RoamTriangle *triangle)
96 for (int i = 0; i < 3; i++) {
97 point->norm[i] *= point->tris;
98 point->norm[i] += triangle->norm[i];
101 for (int i = 0; i < 3; i++)
102 point->norm[i] /= point->tris;
106 * roam_point_remove_triangle:
108 * @triangle: the to add
110 * Un-associating a triangle with a point and update it's vertex normal.
112 void roam_point_remove_triangle(RoamPoint *point, RoamTriangle *triangle)
114 for (int i = 0; i < 3; i++) {
115 point->norm[i] *= point->tris;
116 point->norm[i] -= triangle->norm[i];
120 for (int i = 0; i < 3; i++)
121 point->norm[i] /= point->tris;
125 * roam_point_update_height:
128 * Update the height (elevation) of a point based on the current height function
130 void roam_point_update_height(RoamPoint *point)
132 if (point->height_func) {
133 gdouble elev = point->height_func(
134 point->lat, point->lon, point->height_data);
135 lle2xyz(point->lat, point->lon, elev,
136 &point->x, &point->y, &point->z);
141 * roam_point_update_projection:
143 * @view: the view to use when projecting the point
145 * Updated the screen-space projection of a point.
147 void roam_point_update_projection(RoamPoint *point, RoamView *view)
149 static int count = 0;
150 static int version = 0;
151 if (version != view->version) {
152 g_debug("RoamPoint: Projected %d points", count);
154 version = view->version;
157 if (point->pversion != view->version) {
158 /* Cache projection */
159 gluProject(point->x, point->y, point->z,
160 view->model, view->proj, view->view,
161 &point->px, &point->py, &point->pz);
162 point->pversion = view->version;
173 * @m: the middle point
174 * @r: the right point
176 * Create a new triangle consisting of three points.
178 * Returns: the new triangle
180 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
183 RoamTriangle *triangle = g_new0(RoamTriangle, 1);
189 triangle->parent = parent;
190 triangle->split = roam_point_new(
192 (ABS(l->lat) == 90 ? r->lon :
193 ABS(r->lat) == 90 ? l->lon :
194 lon_avg(l->lon, r->lon)),
195 (l->elev + r->elev)/2);
196 /* TODO: Move this back to sphere, or actually use the nesting */
197 triangle->split->height_func = m->height_func;
198 triangle->split->height_data = m->height_data;
199 roam_point_update_height(triangle->split);
200 //if ((float)triangle->split->lat > 44 && (float)triangle->split->lat < 46)
201 // g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
202 // l->lat, m->lat, r->lat, triangle->split->lat);
203 //if ((float)l->lat == (float)r->lat &&
204 // (float)triangle->split->lat != (float)l->lat)
205 // g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
206 // triangle->split->lat, l->lat);
209 crossd3((gdouble*)triangle->p.l,
210 (gdouble*)triangle->p.m,
211 (gdouble*)triangle->p.r, triangle->norm);
212 normd(triangle->norm);
214 /* Store bounding box, for get_intersect */
215 RoamPoint *p[] = {l,m,r};
216 triangle->edge.n = -90; triangle->edge.s = 90;
217 triangle->edge.e = -180; triangle->edge.w = 180;
218 gboolean maxed = FALSE;
219 for (int i = 0; i < G_N_ELEMENTS(p); i++) {
220 triangle->edge.n = MAX(triangle->edge.n, p[i]->lat);
221 triangle->edge.s = MIN(triangle->edge.s, p[i]->lat);
222 if (p[i]->lat == 90 || p[i]->lat == -90)
224 if (p[i]->lon == 180) {
228 triangle->edge.e = MAX(triangle->edge.e, p[i]->lon);
229 triangle->edge.w = MIN(triangle->edge.w, p[i]->lon);
232 if (triangle->edge.e < 0)
233 triangle->edge.w = -180;
235 triangle->edge.e = 180;
238 //g_message("roam_triangle_new: %p", triangle);
243 * roam_triangle_free:
244 * @triangle: the triangle
246 * Free data associated with a triangle
248 void roam_triangle_free(RoamTriangle *triangle)
250 g_free(triangle->split);
256 * @triangle: the triangle
257 * @left: the left neighbor
258 * @base: the base neighbor
259 * @right: the right neighbor
260 * @sphere: the sphere to add the triangle to
262 * Add a triangle into the sphere's mesh using the given neighbors.
264 void roam_triangle_add(RoamTriangle *triangle,
265 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
268 triangle->t.l = left;
269 triangle->t.b = base;
270 triangle->t.r = right;
272 roam_point_add_triangle(triangle->p.l, triangle);
273 roam_point_add_triangle(triangle->p.m, triangle);
274 roam_point_add_triangle(triangle->p.r, triangle);
277 roam_triangle_update_errors(triangle, sphere);
279 triangle->handle = g_pqueue_push(sphere->triangles, triangle);
283 * roam_triangle_remove:
284 * @triangle: the triangle
285 * @sphere: the sphere to remove the triangle from
287 * Remove a triangle from a sphere's mesh.
289 void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
291 /* Update vertex normals */
292 roam_point_remove_triangle(triangle->p.l, triangle);
293 roam_point_remove_triangle(triangle->p.m, triangle);
294 roam_point_remove_triangle(triangle->p.r, triangle);
296 g_pqueue_remove(sphere->triangles, triangle->handle);
299 /* (neight->t.? == old) = new */
300 static void roam_triangle_sync_neighbors(RoamTriangle *neigh, RoamTriangle *old, RoamTriangle *new)
302 if (neigh->t.l == old) neigh->t.l = new;
303 else if (neigh->t.b == old) neigh->t.b = new;
304 else if (neigh->t.r == old) neigh->t.r = new;
307 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
309 RoamPoint *l = triangle->p.l;
310 RoamPoint *m = triangle->p.m;
311 RoamPoint *r = triangle->p.r;
312 gdouble min_x = MIN(MIN(l->px, m->px), r->px);
313 gdouble max_x = MAX(MAX(l->px, m->px), r->px);
314 gdouble min_y = MIN(MIN(l->py, m->py), r->py);
315 gdouble max_y = MAX(MAX(l->py, m->py), r->py);
316 gint *view = sphere->view->view;
317 return !(max_x < view[0] || min_x > view[2] ||
318 max_y < view[1] || min_y > view[3]) &&
319 l->pz > 0 && m->pz > 0 && r->pz > 0 &&
320 l->pz < 1 && m->pz < 1 && r->pz < 1;
323 static gboolean roam_triangle_backface(RoamTriangle *triangle, RoamSphere *sphere)
325 RoamPoint *l = triangle->p.l;
326 RoamPoint *m = triangle->p.m;
327 RoamPoint *r = triangle->p.r;
328 roam_point_update_projection(l, sphere->view);
329 roam_point_update_projection(m, sphere->view);
330 roam_point_update_projection(r, sphere->view);
331 double size = -( l->px * (m->py - r->py) +
332 m->px * (r->py - l->py) +
333 r->px * (l->py - m->py) ) / 2.0;
338 * roam_triangle_update_errors:
339 * @triangle: the triangle
340 * @sphere: the sphere to use when updating errors
342 * Update the error value associated with a triangle. Called when the view
345 void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
348 roam_point_update_projection(triangle->p.l, sphere->view);
349 roam_point_update_projection(triangle->p.m, sphere->view);
350 roam_point_update_projection(triangle->p.r, sphere->view);
352 if (!roam_triangle_visible(triangle, sphere)) {
353 triangle->error = -1;
355 roam_point_update_projection(triangle->split, sphere->view);
356 RoamPoint *l = triangle->p.l;
357 RoamPoint *m = triangle->p.m;
358 RoamPoint *r = triangle->p.r;
359 RoamPoint *split = triangle->split;
361 /* l-r midpoint projected l-r midpoint */
362 gdouble pxdist = (l->px + r->px)/2 - split->px;
363 gdouble pydist = (l->py + r->py)/2 - split->py;
365 triangle->error = sqrt(pxdist*pxdist + pydist*pydist);
367 /* Multiply by size of triangle */
368 double size = -( l->px * (m->py - r->py) +
369 m->px * (r->py - l->py) +
370 r->px * (l->py - m->py) ) / 2.0;
372 /* Size < 0 == backface */
373 triangle->error *= size;
375 /* Give some preference to "edge" faces */
376 if (roam_triangle_backface(triangle->t.l, sphere) ||
377 roam_triangle_backface(triangle->t.b, sphere) ||
378 roam_triangle_backface(triangle->t.r, sphere))
379 triangle->error *= 500;
384 * roam_triangle_split:
385 * @triangle: the triangle
386 * @sphere: the sphere
388 * Split a triangle into two child triangles and update the sphere.
391 void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
393 //g_message("roam_triangle_split: %p, e=%f\n", triangle, triangle->error);
397 if (triangle != triangle->t.b->t.b)
398 roam_triangle_split(triangle->t.b, sphere);
399 if (triangle != triangle->t.b->t.b)
400 g_assert_not_reached();
402 RoamTriangle *s = triangle; // Self
403 RoamTriangle *b = triangle->t.b; // Base
405 RoamDiamond *dia = roam_diamond_new(s, b);
407 /* Add new triangles */
408 RoamPoint *mid = triangle->split;
409 RoamTriangle *sl = s->kids[0] = roam_triangle_new(s->p.m, mid, s->p.l, dia); // Self Left
410 RoamTriangle *sr = s->kids[1] = roam_triangle_new(s->p.r, mid, s->p.m, dia); // Self Right
411 RoamTriangle *bl = b->kids[0] = roam_triangle_new(b->p.m, mid, b->p.l, dia); // Base Left
412 RoamTriangle *br = b->kids[1] = roam_triangle_new(b->p.r, mid, b->p.m, dia); // Base Right
414 /* triangle,l, base, r, sphere */
415 roam_triangle_add(sl, sr, s->t.l, br, sphere);
416 roam_triangle_add(sr, bl, s->t.r, sl, sphere);
417 roam_triangle_add(bl, br, b->t.l, sr, sphere);
418 roam_triangle_add(br, sl, b->t.r, bl, sphere);
420 roam_triangle_sync_neighbors(s->t.l, s, sl);
421 roam_triangle_sync_neighbors(s->t.r, s, sr);
422 roam_triangle_sync_neighbors(b->t.l, b, bl);
423 roam_triangle_sync_neighbors(b->t.r, b, br);
425 /* Remove old triangles */
426 roam_triangle_remove(s, sphere);
427 roam_triangle_remove(b, sphere);
429 /* Add/Remove diamonds */
430 roam_diamond_update_errors(dia, sphere);
431 roam_diamond_add(dia, sphere);
432 roam_diamond_remove(s->parent, sphere);
433 roam_diamond_remove(b->parent, sphere);
437 * roam_triangle_draw:
438 * @triangle: the triangle
440 * Draw the triangle. Use for debugging.
442 void roam_triangle_draw(RoamTriangle *triangle)
444 glBegin(GL_TRIANGLES);
445 glNormal3dv(triangle->p.r->norm); glVertex3dv((double*)triangle->p.r);
446 glNormal3dv(triangle->p.m->norm); glVertex3dv((double*)triangle->p.m);
447 glNormal3dv(triangle->p.l->norm); glVertex3dv((double*)triangle->p.l);
453 * roam_triangle_draw_normal:
454 * @triangle: the triangle
456 * Draw a normal vector for the triangle. Used while debugging.
458 void roam_triangle_draw_normal(RoamTriangle *triangle)
461 (triangle->p.l->x + triangle->p.m->x + triangle->p.r->x)/3.0,
462 (triangle->p.l->y + triangle->p.m->y + triangle->p.r->y)/3.0,
463 (triangle->p.l->z + triangle->p.m->z + triangle->p.r->z)/3.0,
466 center[0]+triangle->norm[0]*2000000,
467 center[1]+triangle->norm[1]*2000000,
468 center[2]+triangle->norm[2]*2000000,
481 * @parent0: a parent triangle
482 * @parent1: a parent triangle
483 * @kid0: a child triangle
484 * @kid1: a child triangle
485 * @kid2: a child triangle
486 * @kid3: a child triangle
488 * Create a diamond to store information about two split triangles.
490 * Returns: the new diamond
492 RoamDiamond *roam_diamond_new(RoamTriangle *parent0, RoamTriangle *parent1)
494 RoamDiamond *diamond = g_new0(RoamDiamond, 1);
495 diamond->parents[0] = parent0;
496 diamond->parents[1] = parent1;
502 * @diamond: the diamond
503 * @sphere: the sphere to add the diamond to
505 * Add a diamond into the sphere's pool of diamonds. It will be check for
508 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere)
510 diamond->active = TRUE;
511 diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
512 diamond->handle = g_pqueue_push(sphere->diamonds, diamond);
516 * roam_diamond_remove:
517 * @diamond: the diamond
518 * @sphere: the sphere to remove the diamond from
520 * Remove a diamond from the sphere's pool of diamonds.
522 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere)
524 if (diamond && diamond->active) {
525 diamond->active = FALSE;
526 g_pqueue_remove(sphere->diamonds, diamond->handle);
531 * roam_diamond_merge:
532 * @diamond: the diamond
533 * @sphere: the sphere
535 * "Merge" a diamond back into two parent triangles. The original two triangles
536 * are added back into the sphere and the four child triangles as well as the
537 * diamond are removed.
539 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
541 //g_message("roam_diamond_merge: %p, e=%f\n", diamond, diamond->error);
543 /* TODO: pick the best split */
546 /* Use nicer temp names */
547 RoamTriangle *s = diamond->parents[0]; // Self
548 RoamTriangle *b = diamond->parents[1]; // Base
550 RoamTriangle *sl = s->kids[0];
551 RoamTriangle *sr = s->kids[1];
552 RoamTriangle *bl = b->kids[0];
553 RoamTriangle *br = b->kids[1];
555 s->kids[0] = s->kids[1] = NULL;
556 b->kids[0] = b->kids[1] = NULL;
558 /* Add original triangles */
559 roam_triangle_sync_neighbors(s->t.l, sl, s);
560 roam_triangle_sync_neighbors(s->t.r, sr, s);
561 roam_triangle_sync_neighbors(b->t.l, bl, b);
562 roam_triangle_sync_neighbors(b->t.r, br, b);
564 roam_triangle_add(s, sl->t.b, b, sr->t.b, sphere);
565 roam_triangle_add(b, bl->t.b, s, br->t.b, sphere);
567 roam_triangle_sync_neighbors(sl->t.b, sl, s);
568 roam_triangle_sync_neighbors(sr->t.b, sr, s);
569 roam_triangle_sync_neighbors(bl->t.b, bl, b);
570 roam_triangle_sync_neighbors(br->t.b, br, b);
572 /* Remove child triangles */
573 roam_triangle_remove(sl, sphere);
574 roam_triangle_remove(sr, sphere);
575 roam_triangle_remove(bl, sphere);
576 roam_triangle_remove(br, sphere);
578 /* Add/Remove triangles */
579 if (s->t.l->t.l == s->t.r->t.r &&
580 s->t.l->t.l != s && s->parent) {
581 roam_diamond_update_errors(s->parent, sphere);
582 roam_diamond_add(s->parent, sphere);
585 if (b->t.l->t.l == b->t.r->t.r &&
586 b->t.l->t.l != b && b->parent) {
587 roam_diamond_update_errors(b->parent, sphere);
588 roam_diamond_add(b->parent, sphere);
591 /* Remove and free diamond and child triangles */
592 roam_diamond_remove(diamond, sphere);
593 g_assert(sl->p.m == sr->p.m &&
594 sr->p.m == bl->p.m &&
596 g_assert(sl->p.m->tris == 0);
597 roam_triangle_free(sl);
598 roam_triangle_free(sr);
599 roam_triangle_free(bl);
600 roam_triangle_free(br);
605 * roam_diamond_update_errors:
606 * @diamond: the diamond
607 * @sphere: the sphere to use when updating errors
609 * Update the error value associated with a diamond. Called when the view
612 void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere)
614 roam_triangle_update_errors(diamond->parents[0], sphere);
615 roam_triangle_update_errors(diamond->parents[1], sphere);
616 diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
625 * Create a new sphere
627 * Returns: the sphere
629 RoamSphere *roam_sphere_new()
631 RoamSphere *sphere = g_new0(RoamSphere, 1);
633 sphere->triangles = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
634 sphere->diamonds = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
636 RoamPoint *vertexes[] = {
637 roam_point_new( 90, 0, 0), // 0 (North)
638 roam_point_new(-90, 0, 0), // 1 (South)
639 roam_point_new( 0, 0, 0), // 2 (Europe/Africa)
640 roam_point_new( 0, 90, 0), // 3 (Asia,East)
641 roam_point_new( 0, 180, 0), // 4 (Pacific)
642 roam_point_new( 0, -90, 0), // 5 (Americas,West)
644 int _triangles[][2][3] = {
645 /*lv mv rv ln, bn, rn */
646 {{2,0,3}, {3, 4, 1}}, // 0
647 {{3,0,4}, {0, 5, 2}}, // 1
648 {{4,0,5}, {1, 6, 3}}, // 2
649 {{5,0,2}, {2, 7, 0}}, // 3
650 {{3,1,2}, {5, 0, 7}}, // 4
651 {{4,1,3}, {6, 1, 4}}, // 5
652 {{5,1,4}, {7, 2, 5}}, // 6
653 {{2,1,5}, {4, 3, 6}}, // 7
656 for (int i = 0; i < 6; i++)
657 roam_point_update_height(vertexes[i]);
658 for (int i = 0; i < 8; i++)
659 sphere->roots[i] = roam_triangle_new(
660 vertexes[_triangles[i][0][0]],
661 vertexes[_triangles[i][0][1]],
662 vertexes[_triangles[i][0][2]],
664 for (int i = 0; i < 8; i++)
665 roam_triangle_add(sphere->roots[i],
666 sphere->roots[_triangles[i][1][0]],
667 sphere->roots[_triangles[i][1][1]],
668 sphere->roots[_triangles[i][1][2]],
670 for (int i = 0; i < 8; i++)
671 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", sphere->roots[i],
672 sphere->roots[i]->edge.n,
673 sphere->roots[i]->edge.s,
674 sphere->roots[i]->edge.e,
675 sphere->roots[i]->edge.w);
681 * roam_sphere_update_view
682 * @sphere: the sphere
684 * Recreate the sphere's view matrices based on the current OpenGL state.
686 void roam_sphere_update_view(RoamSphere *sphere)
689 sphere->view = g_new0(RoamView, 1);
690 glGetDoublev (GL_MODELVIEW_MATRIX, sphere->view->model);
691 glGetDoublev (GL_PROJECTION_MATRIX, sphere->view->proj);
692 glGetIntegerv(GL_VIEWPORT, sphere->view->view);
693 sphere->view->version++;
697 * roam_sphere_update_errors
698 * @sphere: the sphere
700 * Update triangle and diamond errors in the sphere.
702 void roam_sphere_update_errors(RoamSphere *sphere)
704 g_debug("RoamSphere: update_errors - polys=%d", sphere->polys);
705 GPtrArray *tris = g_pqueue_get_array(sphere->triangles);
706 GPtrArray *dias = g_pqueue_get_array(sphere->diamonds);
708 roam_sphere_update_view(sphere);
710 for (int i = 0; i < tris->len; i++) {
711 RoamTriangle *triangle = tris->pdata[i];
712 roam_triangle_update_errors(triangle, sphere);
713 g_pqueue_priority_changed(sphere->triangles, triangle->handle);
716 for (int i = 0; i < dias->len; i++) {
717 RoamDiamond *diamond = dias->pdata[i];
718 roam_diamond_update_errors(diamond, sphere);
719 g_pqueue_priority_changed(sphere->diamonds, diamond->handle);
722 g_ptr_array_free(tris, TRUE);
723 g_ptr_array_free(dias, TRUE);
727 * roam_sphere_split_one
728 * @sphere: the sphere
730 * Split the triangle with the greatest error.
732 void roam_sphere_split_one(RoamSphere *sphere)
734 RoamTriangle *to_split = g_pqueue_peek(sphere->triangles);
735 if (!to_split) return;
736 roam_triangle_split(to_split, sphere);
740 * roam_sphere_merge_one
741 * @sphere: the sphere
743 * Merge the diamond with the lowest error.
745 void roam_sphere_merge_one(RoamSphere *sphere)
747 RoamDiamond *to_merge = g_pqueue_peek(sphere->diamonds);
748 if (!to_merge) return;
749 roam_diamond_merge(to_merge, sphere);
753 * roam_sphere_split_merge
754 * @sphere: the sphere
756 * Perform a predetermined number split-merge iterations.
758 * Returns: the number splits and merges done
760 gint roam_sphere_split_merge(RoamSphere *sphere)
762 gint iters = 0, max_iters = 500;
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);