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 #GisOpenGL
25 * when drawing surface textures for GisTiles.
27 * This implementation of the ROAM algorithm is based on an octahedron as the
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)
182 RoamTriangle *triangle = g_new0(RoamTriangle, 1);
188 triangle->split = roam_point_new(
190 (ABS(l->lat) == 90 ? r->lon :
191 ABS(r->lat) == 90 ? l->lon :
192 lon_avg(l->lon, r->lon)),
193 (l->elev + r->elev)/2);
194 /* TODO: Move this back to sphere, or actually use the nesting */
195 triangle->split->height_func = m->height_func;
196 triangle->split->height_data = m->height_data;
197 roam_point_update_height(triangle->split);
198 //if ((float)triangle->split->lat > 44 && (float)triangle->split->lat < 46)
199 // g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
200 // l->lat, m->lat, r->lat, triangle->split->lat);
201 //if ((float)l->lat == (float)r->lat &&
202 // (float)triangle->split->lat != (float)l->lat)
203 // g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
204 // triangle->split->lat, l->lat);
209 pa[0] = triangle->p.l->x - triangle->p.m->x;
210 pa[1] = triangle->p.l->y - triangle->p.m->y;
211 pa[2] = triangle->p.l->z - triangle->p.m->z;
213 pb[0] = triangle->p.r->x - triangle->p.m->x;
214 pb[1] = triangle->p.r->y - triangle->p.m->y;
215 pb[2] = triangle->p.r->z - triangle->p.m->z;
217 triangle->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
218 triangle->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
219 triangle->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
221 double total = sqrt(triangle->norm[0] * triangle->norm[0] +
222 triangle->norm[1] * triangle->norm[1] +
223 triangle->norm[2] * triangle->norm[2]);
225 triangle->norm[0] /= total;
226 triangle->norm[1] /= total;
227 triangle->norm[2] /= total;
229 /* Store bounding box, for get_intersect */
230 RoamPoint *p[] = {l,m,r};
231 triangle->edge.n = -90; triangle->edge.s = 90;
232 triangle->edge.e = -180; triangle->edge.w = 180;
233 gboolean maxed = FALSE;
234 for (int i = 0; i < G_N_ELEMENTS(p); i++) {
235 triangle->edge.n = MAX(triangle->edge.n, p[i]->lat);
236 triangle->edge.s = MIN(triangle->edge.s, p[i]->lat);
237 if (p[i]->lat == 90 || p[i]->lat == -90)
239 if (p[i]->lon == 180) {
243 triangle->edge.e = MAX(triangle->edge.e, p[i]->lon);
244 triangle->edge.w = MIN(triangle->edge.w, p[i]->lon);
247 if (triangle->edge.e < 0)
248 triangle->edge.w = -180;
250 triangle->edge.e = 180;
253 //g_message("roam_triangle_new: %p", triangle);
258 * roam_triangle_free:
259 * @triangle: the triangle
261 * Free data associated with a triangle
263 void roam_triangle_free(RoamTriangle *triangle)
265 g_free(triangle->split);
271 * @triangle: the triangle
272 * @left: the left neighbor
273 * @base: the base neighbor
274 * @right: the right neighbor
275 * @sphere: the sphere to add the triangle to
277 * Add a triangle into the sphere's mesh using the given neighbors.
279 void roam_triangle_add(RoamTriangle *triangle,
280 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
283 triangle->t.l = left;
284 triangle->t.b = base;
285 triangle->t.r = right;
287 roam_point_add_triangle(triangle->p.l, triangle);
288 roam_point_add_triangle(triangle->p.m, triangle);
289 roam_point_add_triangle(triangle->p.r, triangle);
292 roam_triangle_update_errors(triangle, sphere);
294 triangle->handle = g_pqueue_push(sphere->triangles, triangle);
298 * roam_triangle_remove:
299 * @triangle: the triangle
300 * @sphere: the sphere to remove the triangle from
302 * Remove a triangle from a sphere's mesh.
304 void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
306 /* Update vertex normals */
307 roam_point_remove_triangle(triangle->p.l, triangle);
308 roam_point_remove_triangle(triangle->p.m, triangle);
309 roam_point_remove_triangle(triangle->p.r, triangle);
311 g_pqueue_remove(sphere->triangles, triangle->handle);
314 static void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
316 if (neigh->t.l == old) neigh->t.l = new;
317 else if (neigh->t.b == old) neigh->t.b = new;
318 else if (neigh->t.r == old) neigh->t.r = new;
319 else g_assert_not_reached();
322 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
324 RoamPoint *l = triangle->p.l;
325 RoamPoint *m = triangle->p.m;
326 RoamPoint *r = triangle->p.r;
327 gdouble min_x = MIN(MIN(l->px, m->px), r->px);
328 gdouble max_x = MAX(MAX(l->px, m->px), r->px);
329 gdouble min_y = MIN(MIN(l->py, m->py), r->py);
330 gdouble max_y = MAX(MAX(l->py, m->py), r->py);
331 gint *view = sphere->view->view;
332 return !(max_x < view[0] || min_x > view[2] ||
333 max_y < view[1] || min_y > view[3]) &&
334 l->pz > 0 && m->pz > 0 && r->pz > 0 &&
335 l->pz < 1 && m->pz < 1 && r->pz < 1;
339 * roam_triangle_update_errors:
340 * @triangle: the triangle
341 * @sphere: the sphere to use when updating errors
343 * Update the error value associated with a triangle. Called when the view
346 void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
349 roam_point_update_projection(triangle->p.l, sphere->view);
350 roam_point_update_projection(triangle->p.m, sphere->view);
351 roam_point_update_projection(triangle->p.r, sphere->view);
353 if (!roam_triangle_visible(triangle, sphere)) {
354 triangle->error = -1;
356 roam_point_update_projection(triangle->split, sphere->view);
357 RoamPoint *l = triangle->p.l;
358 RoamPoint *m = triangle->p.m;
359 RoamPoint *r = triangle->p.r;
360 RoamPoint *split = triangle->split;
362 /* l-r midpoint projected l-r midpoint */
363 gdouble pxdist = (l->px + r->px)/2 - split->px;
364 gdouble pydist = (l->py + r->py)/2 - split->py;
366 triangle->error = sqrt(pxdist*pxdist + pydist*pydist);
368 /* Multiply by size of triangle */
369 double size = -( l->px * (m->py - r->py) +
370 m->px * (r->py - l->py) +
371 r->px * (l->py - m->py) ) / 2.0;
373 /* Size < 0 == backface */
374 triangle->error *= size;
379 * roam_triangle_split:
380 * @triangle: the triangle
381 * @sphere: the sphere
383 * Split a triangle into two child triangles and update the sphere.
386 void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
388 //g_message("roam_triangle_split: %p, e=%f\n", triangle, triangle->error);
392 if (triangle != triangle->t.b->t.b)
393 roam_triangle_split(triangle->t.b, sphere);
394 if (triangle != triangle->t.b->t.b)
395 g_assert_not_reached();
397 RoamTriangle *s = triangle; // Self
398 RoamTriangle *b = triangle->t.b; // Base
400 /* Add new triangles */
401 RoamPoint *mid = triangle->split;
402 RoamTriangle *sl = s->kids[0] = roam_triangle_new(s->p.m, mid, s->p.l); // Self Left
403 RoamTriangle *sr = s->kids[1] = roam_triangle_new(s->p.r, mid, s->p.m); // Self Right
404 RoamTriangle *bl = b->kids[0] = roam_triangle_new(b->p.m, mid, b->p.l); // Base Left
405 RoamTriangle *br = b->kids[1] = roam_triangle_new(b->p.r, mid, b->p.m); // Base Right
407 /* triangle,l, base, r, sphere */
408 roam_triangle_add(sl, sr, s->t.l, br, sphere);
409 roam_triangle_add(sr, bl, s->t.r, sl, sphere);
410 roam_triangle_add(bl, br, b->t.l, sr, sphere);
411 roam_triangle_add(br, sl, b->t.r, bl, sphere);
413 roam_triangle_sync_neighbors(sl, s, s->t.l);
414 roam_triangle_sync_neighbors(sr, s, s->t.r);
415 roam_triangle_sync_neighbors(bl, b, b->t.l);
416 roam_triangle_sync_neighbors(br, b, b->t.r);
418 /* Remove old triangles */
419 roam_triangle_remove(s, sphere);
420 roam_triangle_remove(b, sphere);
422 /* Add/Remove diamonds */
423 RoamDiamond *diamond = roam_diamond_new(s, b, sl, sr, bl, br);
424 roam_diamond_update_errors(diamond, sphere);
425 roam_diamond_add(diamond, sphere);
426 roam_diamond_remove(s->parent, sphere);
427 roam_diamond_remove(b->parent, sphere);
431 * roam_triangle_draw:
432 * @triangle: the triangle
434 * Draw the triangle. Use for debugging.
436 void roam_triangle_draw(RoamTriangle *triangle)
438 glBegin(GL_TRIANGLES);
439 glNormal3dv(triangle->p.r->norm); glVertex3dv((double*)triangle->p.r);
440 glNormal3dv(triangle->p.m->norm); glVertex3dv((double*)triangle->p.m);
441 glNormal3dv(triangle->p.l->norm); glVertex3dv((double*)triangle->p.l);
447 * roam_triangle_draw_normal:
448 * @triangle: the triangle
450 * Draw a normal vector for the triangle. Used while debugging.
452 void roam_triangle_draw_normal(RoamTriangle *triangle)
455 (triangle->p.l->x + triangle->p.m->x + triangle->p.r->x)/3.0,
456 (triangle->p.l->y + triangle->p.m->y + triangle->p.r->y)/3.0,
457 (triangle->p.l->z + triangle->p.m->z + triangle->p.r->z)/3.0,
460 center[0]+triangle->norm[0]*2000000,
461 center[1]+triangle->norm[1]*2000000,
462 center[2]+triangle->norm[2]*2000000,
475 * @parent0: a parent triangle
476 * @parent1: a parent triangle
477 * @kid0: a child triangle
478 * @kid1: a child triangle
479 * @kid2: a child triangle
480 * @kid3: a child triangle
482 * Create a diamond to store information about two split triangles.
484 * Returns: the new diamond
486 RoamDiamond *roam_diamond_new(
487 RoamTriangle *parent0, RoamTriangle *parent1,
488 RoamTriangle *kid0, RoamTriangle *kid1,
489 RoamTriangle *kid2, RoamTriangle *kid3)
491 RoamDiamond *diamond = g_new0(RoamDiamond, 1);
493 diamond->kids[0] = kid0;
494 diamond->kids[1] = kid1;
495 diamond->kids[2] = kid2;
496 diamond->kids[3] = kid3;
498 kid0->parent = diamond;
499 kid1->parent = diamond;
500 kid2->parent = diamond;
501 kid3->parent = diamond;
503 diamond->parents[0] = parent0;
504 diamond->parents[1] = parent1;
511 * @diamond: the diamond
512 * @sphere: the sphere to add the diamond to
514 * Add a diamond into the sphere's pool of diamonds. It will be check for
517 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere)
519 diamond->active = TRUE;
520 diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
521 diamond->handle = g_pqueue_push(sphere->diamonds, diamond);
525 * roam_diamond_remove:
526 * @diamond: the diamond
527 * @sphere: the sphere to remove the diamond from
529 * Remove a diamond from the sphere's pool of diamonds.
531 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere)
533 if (diamond && diamond->active) {
534 diamond->active = FALSE;
535 g_pqueue_remove(sphere->diamonds, diamond->handle);
540 * roam_diamond_merge:
541 * @diamond: the diamond
542 * @sphere: the sphere
544 * "Merge" a diamond back into two parent triangles. The original two triangles
545 * are added back into the sphere and the four child triangles as well as the
546 * diamond are removed.
548 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
550 //g_message("roam_diamond_merge: %p, e=%f\n", diamond, diamond->error);
552 /* TODO: pick the best split */
555 /* Use nicer temp names */
556 RoamTriangle *s = diamond->parents[0]; // Self
557 RoamTriangle *b = diamond->parents[1]; // Base
559 RoamTriangle *sl = diamond->kids[0];
560 RoamTriangle *sr = diamond->kids[1];
561 RoamTriangle *bl = diamond->kids[2];
562 RoamTriangle *br = diamond->kids[3];
564 s->kids[0] = s->kids[1] = NULL;
565 b->kids[0] = b->kids[1] = NULL;
567 /* Add original triangles */
568 roam_triangle_add(s, sl->t.b, b, sr->t.b, sphere);
569 roam_triangle_add(b, bl->t.b, s, br->t.b, sphere);
571 roam_triangle_sync_neighbors(s, sl, sl->t.b);
572 roam_triangle_sync_neighbors(s, sr, sr->t.b);
573 roam_triangle_sync_neighbors(b, bl, bl->t.b);
574 roam_triangle_sync_neighbors(b, br, br->t.b);
576 /* Remove child triangles */
577 roam_triangle_remove(sl, sphere);
578 roam_triangle_remove(sr, sphere);
579 roam_triangle_remove(bl, sphere);
580 roam_triangle_remove(br, sphere);
582 /* Add/Remove triangles */
583 if (s->t.l->t.l == s->t.r->t.r &&
584 s->t.l->t.l != s && s->parent) {
585 roam_diamond_update_errors(s->parent, sphere);
586 roam_diamond_add(s->parent, sphere);
589 if (b->t.l->t.l == b->t.r->t.r &&
590 b->t.l->t.l != b && b->parent) {
591 roam_diamond_update_errors(b->parent, sphere);
592 roam_diamond_add(b->parent, sphere);
595 /* Remove and free diamond and child triangles */
596 roam_diamond_remove(diamond, sphere);
597 g_assert(sl->p.m == sr->p.m &&
598 sr->p.m == bl->p.m &&
600 g_assert(sl->p.m->tris == 0);
601 roam_triangle_free(sl);
602 roam_triangle_free(sr);
603 roam_triangle_free(bl);
604 roam_triangle_free(br);
609 * roam_diamond_update_errors:
610 * @diamond: the diamond
611 * @sphere: the sphere to use when updating errors
613 * Update the error value associated with a diamond. Called when the view
616 void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere)
618 roam_triangle_update_errors(diamond->parents[0], sphere);
619 roam_triangle_update_errors(diamond->parents[1], sphere);
620 diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
629 * Create a new sphere
631 * Returns: the sphere
633 RoamSphere *roam_sphere_new()
635 RoamSphere *sphere = g_new0(RoamSphere, 1);
637 sphere->triangles = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
638 sphere->diamonds = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
640 RoamPoint *vertexes[] = {
641 roam_point_new( 90, 0, 0), // 0 (North)
642 roam_point_new(-90, 0, 0), // 1 (South)
643 roam_point_new( 0, 0, 0), // 2 (Europe/Africa)
644 roam_point_new( 0, 90, 0), // 3 (Asia,East)
645 roam_point_new( 0, 180, 0), // 4 (Pacific)
646 roam_point_new( 0, -90, 0), // 5 (Americas,West)
648 int _triangles[][2][3] = {
649 /*lv mv rv ln, bn, rn */
650 {{2,0,3}, {3, 4, 1}}, // 0
651 {{3,0,4}, {0, 5, 2}}, // 1
652 {{4,0,5}, {1, 6, 3}}, // 2
653 {{5,0,2}, {2, 7, 0}}, // 3
654 {{3,1,2}, {5, 0, 7}}, // 4
655 {{4,1,3}, {6, 1, 4}}, // 5
656 {{5,1,4}, {7, 2, 5}}, // 6
657 {{2,1,5}, {4, 3, 6}}, // 7
660 for (int i = 0; i < 6; i++)
661 roam_point_update_height(vertexes[i]);
662 for (int i = 0; i < 8; i++)
663 sphere->roots[i] = roam_triangle_new(
664 vertexes[_triangles[i][0][0]],
665 vertexes[_triangles[i][0][1]],
666 vertexes[_triangles[i][0][2]]);
667 for (int i = 0; i < 8; i++)
668 roam_triangle_add(sphere->roots[i],
669 sphere->roots[_triangles[i][1][0]],
670 sphere->roots[_triangles[i][1][1]],
671 sphere->roots[_triangles[i][1][2]],
673 for (int i = 0; i < 8; i++)
674 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", sphere->roots[i],
675 sphere->roots[i]->edge.n,
676 sphere->roots[i]->edge.s,
677 sphere->roots[i]->edge.e,
678 sphere->roots[i]->edge.w);
684 * roam_sphere_update_view
685 * @sphere: the sphere
687 * Recreate the sphere's view matrices based on the current OpenGL state.
689 void roam_sphere_update_view(RoamSphere *sphere)
692 sphere->view = g_new0(RoamView, 1);
693 glGetDoublev (GL_MODELVIEW_MATRIX, sphere->view->model);
694 glGetDoublev (GL_PROJECTION_MATRIX, sphere->view->proj);
695 glGetIntegerv(GL_VIEWPORT, sphere->view->view);
696 sphere->view->version++;
700 * roam_sphere_update_errors
701 * @sphere: the sphere
703 * Update triangle and diamond errors in the sphere.
705 void roam_sphere_update_errors(RoamSphere *sphere)
707 g_debug("RoamSphere: update_errors - polys=%d", sphere->polys);
708 GPtrArray *tris = g_pqueue_get_array(sphere->triangles);
709 GPtrArray *dias = g_pqueue_get_array(sphere->diamonds);
711 roam_sphere_update_view(sphere);
713 for (int i = 0; i < tris->len; i++) {
714 RoamTriangle *triangle = tris->pdata[i];
715 roam_triangle_update_errors(triangle, sphere);
716 g_pqueue_priority_changed(sphere->triangles, triangle->handle);
719 for (int i = 0; i < dias->len; i++) {
720 RoamDiamond *diamond = dias->pdata[i];
721 roam_diamond_update_errors(diamond, sphere);
722 g_pqueue_priority_changed(sphere->diamonds, diamond->handle);
725 g_ptr_array_free(tris, TRUE);
726 g_ptr_array_free(dias, TRUE);
730 * roam_sphere_split_one
731 * @sphere: the sphere
733 * Split the triangle with the greatest error.
735 void roam_sphere_split_one(RoamSphere *sphere)
737 RoamTriangle *to_split = g_pqueue_peek(sphere->triangles);
738 if (!to_split) return;
739 roam_triangle_split(to_split, sphere);
743 * roam_sphere_merge_one
744 * @sphere: the sphere
746 * Merge the diamond with the lowest error.
748 void roam_sphere_merge_one(RoamSphere *sphere)
750 RoamDiamond *to_merge = g_pqueue_peek(sphere->diamonds);
751 if (!to_merge) return;
752 roam_diamond_merge(to_merge, sphere);
756 * roam_sphere_split_merge
757 * @sphere: the sphere
759 * Perform a predetermined number split-merge iterations.
761 * Returns: the number splits and merges done
763 gint roam_sphere_split_merge(RoamSphere *sphere)
765 gint iters = 0, max_iters = 500;
766 //gint target = 4000;
773 if (target - sphere->polys > 100) {
774 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, sphere->polys);
775 while (sphere->polys < target && iters++ < max_iters)
776 roam_sphere_split_one(sphere);
779 if (sphere->polys - target > 100) {
780 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", sphere->polys, target);
781 while (sphere->polys > target && iters++ < max_iters)
782 roam_sphere_merge_one(sphere);
785 while (((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error >
786 ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error &&
787 iters++ < max_iters) {
788 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
789 // ((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error,
790 // ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error,
791 // iters-1, max_iters);
792 roam_sphere_merge_one(sphere);
793 roam_sphere_split_one(sphere);
801 * @sphere: the sphere
803 * Draw the sphere. Use for debugging.
805 void roam_sphere_draw(RoamSphere *sphere)
807 g_debug("RoamSphere: draw");
808 g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw, NULL);
812 * roam_sphere_draw_normals
813 * @sphere: the sphere
815 * Draw all the surface normal vectors for the sphere. Used while debugging.
817 void roam_sphere_draw_normals(RoamSphere *sphere)
819 g_debug("RoamSphere: draw_normal");
820 g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw_normal, NULL);
823 static GList *_roam_sphere_get_leaves(RoamTriangle *triangle, GList *list, gboolean all)
825 if (triangle->kids[0] && triangle->kids[1]) {
826 if (all) list = g_list_prepend(list, triangle);
827 list = _roam_sphere_get_leaves(triangle->kids[0], list, all);
828 list = _roam_sphere_get_leaves(triangle->kids[1], list, all);
831 return g_list_prepend(list, triangle);
835 static GList *_roam_sphere_get_intersect_rec(RoamTriangle *triangle, GList *list,
836 gboolean all, gdouble n, gdouble s, gdouble e, gdouble w)
838 gdouble tn = triangle->edge.n;
839 gdouble ts = triangle->edge.s;
840 gdouble te = triangle->edge.e;
841 gdouble tw = triangle->edge.w;
843 gboolean debug = FALSE &&
844 n==90 && s==45 && e==-90 && w==-180 &&
848 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
849 triangle, tn, s, ts, n, te, w, tw, e);
850 if (tn <= s || ts >= n || te <= w || tw >= e) {
852 if (debug) g_message("no intersect");
854 } else if (tn <= n && ts >= s && te <= e && tw >= w) {
855 /* Triangle is completely contained */
856 if (debug) g_message("contained");
857 if (all) list = g_list_prepend(list, triangle);
858 return _roam_sphere_get_leaves(triangle, list, all);
859 } else if (triangle->kids[0] && triangle->kids[1]) {
860 /* Paritial intersect with children */
861 if (debug) g_message("edge w/ child");
862 if (all) list = g_list_prepend(list, triangle);
863 list = _roam_sphere_get_intersect_rec(triangle->kids[0], list, all, n, s, e, w);
864 list = _roam_sphere_get_intersect_rec(triangle->kids[1], list, all, n, s, e, w);
867 /* This triangle is an edge case */
868 if (debug) g_message("edge");
869 return g_list_prepend(list, triangle);
874 * roam_sphere_get_intersect
875 * @sphere: the sphere
876 * @all: TRUE if non-leaf triangle should be returned as well
877 * @n: the northern edge
878 * @s: the southern edge
879 * @e: the eastern edge
880 * @w: the western edge
882 * Lookup triangles withing the sphere that intersect a given lat-lon box.
884 * Returns: the list of intersecting triangles.
886 /* Warning: This grabs pointers to triangles which can be changed by other
887 * calls, e.g. split_merge. If you use this, you need to do some locking to
888 * prevent the returned list from becomming stale. */
889 GList *roam_sphere_get_intersect(RoamSphere *sphere, gboolean all,
890 gdouble n, gdouble s, gdouble e, gdouble w)
892 /* I think this is correct..
893 * i_cost = cost for triangle-rectagnle intersect test
894 * time = n_tiles * 2*tris_per_tile * i_cost
895 * time = 30 * 2*333 * i_cost = 20000 * i_cost */
897 for (int i = 0; i < G_N_ELEMENTS(sphere->roots); i++)
898 list = _roam_sphere_get_intersect_rec(sphere->roots[i],
899 list, all, n, s, e, w);
903 static void roam_sphere_free_tri(RoamTriangle *triangle)
905 if (--triangle->p.l->tris == 0) g_free(triangle->p.l);
906 if (--triangle->p.m->tris == 0) g_free(triangle->p.m);
907 if (--triangle->p.r->tris == 0) g_free(triangle->p.r);
908 roam_triangle_free(triangle);
913 * @sphere: the sphere
915 * Free data associated with a sphere
917 void roam_sphere_free(RoamSphere *sphere)
919 g_debug("RoamSphere: free");
920 /* Slow method, but it should work */
921 while (sphere->polys > 8)
922 roam_sphere_merge_one(sphere);
923 /* TODO: free points */
924 g_pqueue_foreach(sphere->triangles, (GFunc)roam_sphere_free_tri, NULL);
925 g_pqueue_free(sphere->triangles);
926 g_pqueue_free(sphere->diamonds);
927 g_free(sphere->view);