Pileus Git - grits/blob - src/roam.c

   1 /*
   2  * Copyright (C) 2009-2010 Andy Spencer <andy753421@gmail.com>
   3  *
   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.
   8  *
   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.
  13  *
  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/>.
  16  */
  17
  18 #include <glib.h>
  19 #include <math.h>
  20 #include <string.h>
  21 #include "gpqueue.h"
  22 #include <GL/gl.h>
  23 #include <GL/glu.h>
  24
  25 #include "gis-util.h"
  26 #include "roam.h"
  27
  28 /**
  29  * TODO:
  30  *   - Optimize for memory consumption
  31  *   - Profile for computation speed
  32  *   - Target polygon count/detail
  33  */
  34
  35 /* For GPQueue comparators */
  36 static gint tri_cmp(RoamTriangle *a, RoamTriangle *b, gpointer data)
  37 {
  38         if      (a->error < b->error) return  1;
  39         else if (a->error > b->error) return -1;
  40         else                          return  0;
  41 }
  42 static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data)
  43 {
  44         if      (a->error < b->error) return -1;
  45         else if (a->error > b->error) return  1;
  46         else                          return  0;
  47 }
  48
  49
  50 /*************
  51  * RoamPoint *
  52  *************/
  53 RoamPoint *roam_point_new(gdouble lat, gdouble lon, gdouble elev)
  54 {
  55         RoamPoint *self = g_new0(RoamPoint, 1);
  56         self->lat  = lat;
  57         self->lon  = lon;
  58         self->elev = elev;
  59         /* For get_intersect */
  60         lle2xyz(lat, lon, elev, &self->x, &self->y, &self->z);
  61         return self;
  62 }
  63 RoamPoint *roam_point_dup(RoamPoint *self)
  64 {
  65         RoamPoint *new = g_memdup(self, sizeof(RoamPoint));
  66         new->tris = 0;
  67         return new;
  68 }
  69 void roam_point_add_triangle(RoamPoint *self, RoamTriangle *triangle)
  70 {
  71         for (int i = 0; i < 3; i++) {
  72                 self->norm[i] *= self->tris;
  73                 self->norm[i] += triangle->norm[i];
  74         }
  75         self->tris++;
  76         for (int i = 0; i < 3; i++)
  77                 self->norm[i] /= self->tris;
  78 }
  79 void roam_point_remove_triangle(RoamPoint *self, RoamTriangle *triangle)
  80 {
  81         for (int i = 0; i < 3; i++) {
  82                 self->norm[i] *= self->tris;
  83                 self->norm[i] -= triangle->norm[i];
  84         }
  85         self->tris--;
  86         if (self->tris)
  87                 for (int i = 0; i < 3; i++)
  88                         self->norm[i] /= self->tris;
  89 }
  90 void roam_point_update_height(RoamPoint *self)
  91 {
  92         if (self->height_func) {
  93                 gdouble elev = self->height_func(
  94                                 self->lat, self->lon, self->height_data);
  95                 lle2xyz(self->lat, self->lon, elev,
  96                                 &self->x, &self->y, &self->z);
  97         }
  98 }
  99 void roam_point_update_projection(RoamPoint *self, RoamSphere *sphere)
 100 {
 101         static int count   = 0;
 102         static int version = 0;
 103         if (version != sphere->view->version) {
 104                 g_debug("Projected %d points", count);
 105                 count   = 0;
 106                 version = sphere->view->version;
 107         }
 108
 109         if (self->pversion != sphere->view->version) {
 110                 /* Cache projection */
 111                 gluProject(self->x, self->y, self->z,
 112                         sphere->view->model, sphere->view->proj, sphere->view->view,
 113                         &self->px, &self->py, &self->pz);
 114                 self->pversion = sphere->view->version;
 115                 count++;
 116         }
 117 }
 118
 119 /****************
 120  * RoamTriangle *
 121  ****************/
 122 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
 123 {
 124         RoamTriangle *self = g_new0(RoamTriangle, 1);
 125
 126         self->error = 0;
 127         self->p.l = l;
 128         self->p.m = m;
 129         self->p.r = r;
 130         self->split = roam_point_new(
 131                 (l->lat + r->lat)/2,
 132                 (ABS(l->lat) == 90 ? r->lon :
 133                  ABS(r->lat) == 90 ? l->lon :
 134                  lon_avg(l->lon, r->lon)),
 135                 (l->elev + r->elev)/2);
 136         /* TODO: Move this back to sphere, or actually use the nesting */
 137         self->split->height_func = m->height_func;
 138         self->split->height_data = m->height_data;
 139         roam_point_update_height(self->split);
 140         //if ((float)self->split->lat > 44 && (float)self->split->lat < 46)
 141         //      g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
 142         //                      l->lat, m->lat, r->lat, self->split->lat);
 143         //if ((float)l->lat == (float)r->lat &&
 144         //    (float)self->split->lat != (float)l->lat)
 145         //      g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
 146         //              self->split->lat, l->lat);
 147
 148         /* Update normal */
 149         double pa[3];
 150         double pb[3];
 151         pa[0] = self->p.l->x - self->p.m->x;
 152         pa[1] = self->p.l->y - self->p.m->y;
 153         pa[2] = self->p.l->z - self->p.m->z;
 154
 155         pb[0] = self->p.r->x - self->p.m->x;
 156         pb[1] = self->p.r->y - self->p.m->y;
 157         pb[2] = self->p.r->z - self->p.m->z;
 158
 159         self->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 160         self->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 161         self->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 162
 163         double total = sqrt(self->norm[0] * self->norm[0] +
 164                             self->norm[1] * self->norm[1] +
 165                             self->norm[2] * self->norm[2]);
 166
 167         self->norm[0] /= total;
 168         self->norm[1] /= total;
 169         self->norm[2] /= total;
 170
 171         /* Store bounding box, for get_intersect */
 172         RoamPoint *p[] = {l,m,r};
 173         self->edge.n =  -90; self->edge.s =  90;
 174         self->edge.e = -180; self->edge.w = 180;
 175         gboolean maxed = FALSE;
 176         for (int i = 0; i < G_N_ELEMENTS(p); i++) {
 177                 self->edge.n = MAX(self->edge.n, p[i]->lat);
 178                 self->edge.s = MIN(self->edge.s, p[i]->lat);
 179                 if (p[i]->lat == 90 || p[i]->lat == -90)
 180                         continue;
 181                 if (p[i]->lon == 180) {
 182                         maxed = TRUE;
 183                         continue;
 184                 }
 185                 self->edge.e = MAX(self->edge.e, p[i]->lon);
 186                 self->edge.w = MIN(self->edge.w, p[i]->lon);
 187         }
 188         if (maxed) {
 189                 if (self->edge.e < 0)
 190                         self->edge.w = -180;
 191                 else
 192                         self->edge.e =  180;
 193         }
 194
 195         //g_message("roam_triangle_new: %p", self);
 196         return self;
 197 }
 198
 199 void roam_triangle_free(RoamTriangle *self)
 200 {
 201         g_free(self->split);
 202         g_free(self);
 203 }
 204
 205 void roam_triangle_add(RoamTriangle *self,
 206                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 207                 RoamSphere *sphere)
 208 {
 209         self->t.l = left;
 210         self->t.b = base;
 211         self->t.r = right;
 212
 213         roam_point_add_triangle(self->p.l, self);
 214         roam_point_add_triangle(self->p.m, self);
 215         roam_point_add_triangle(self->p.r, self);
 216
 217         if (sphere->view)
 218                 roam_triangle_update_errors(self, sphere);
 219
 220         self->handle = g_pqueue_push(sphere->triangles, self);
 221 }
 222
 223 void roam_triangle_remove(RoamTriangle *self, RoamSphere *sphere)
 224 {
 225         /* Update vertex normals */
 226         roam_point_remove_triangle(self->p.l, self);
 227         roam_point_remove_triangle(self->p.m, self);
 228         roam_point_remove_triangle(self->p.r, self);
 229
 230         g_pqueue_remove(sphere->triangles, self->handle);
 231 }
 232
 233 void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
 234 {
 235         if      (neigh->t.l == old) neigh->t.l = new;
 236         else if (neigh->t.b == old) neigh->t.b = new;
 237         else if (neigh->t.r == old) neigh->t.r = new;
 238         else g_assert_not_reached();
 239 }
 240
 241 gboolean roam_point_visible(RoamPoint *self, RoamSphere *sphere)
 242 {
 243         gint *view = sphere->view->view;
 244         return self->px > view[0] && self->px < view[2] &&
 245                self->py > view[1] && self->py < view[3] &&
 246                self->pz > 0       && self->pz < 1;
 247 }
 248 gboolean roam_triangle_visible(RoamTriangle *self, RoamSphere *sphere)
 249 {
 250         /* Do this with a bounding box */
 251         return roam_point_visible(self->p.l, sphere) ||
 252                roam_point_visible(self->p.m, sphere) ||
 253                roam_point_visible(self->p.r, sphere);
 254 }
 255
 256 void roam_triangle_update_errors(RoamTriangle *self, RoamSphere *sphere)
 257 {
 258         /* Update points */
 259         roam_point_update_projection(self->p.l, sphere);
 260         roam_point_update_projection(self->p.m, sphere);
 261         roam_point_update_projection(self->p.r, sphere);
 262
 263         /* Not exactly correct, could be out on both sides (middle in) */
 264         if (!roam_triangle_visible(self, sphere)) {
 265                 self->error = -1;
 266         } else {
 267                 roam_point_update_projection(self->split, sphere);
 268                 RoamPoint *l = self->p.l;
 269                 RoamPoint *m = self->p.m;
 270                 RoamPoint *r = self->p.r;
 271                 RoamPoint *split = self->split;
 272
 273                 /*               l-r midpoint        projected l-r midpoint */
 274                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 275                 gdouble pydist = (l->py + r->py)/2 - split->py;
 276
 277                 self->error = sqrt(pxdist*pxdist + pydist*pydist);
 278
 279                 /* Multiply by size of triangle */
 280                 double size = -( l->px * (m->py - r->py) +
 281                                  m->px * (r->py - l->py) +
 282                                  r->px * (l->py - m->py) ) / 2.0;
 283
 284                 /* Size < 0 == backface */
 285                 //if (size < 0)
 286                 //      self->error *= -1;
 287                 self->error *= size;
 288         }
 289 }
 290
 291 void roam_triangle_split(RoamTriangle *self, RoamSphere *sphere)
 292 {
 293         //g_message("roam_triangle_split: %p, e=%f\n", self, self->error);
 294
 295         sphere->polys += 2;
 296
 297         if (self != self->t.b->t.b)
 298                 roam_triangle_split(self->t.b, sphere);
 299         if (self != self->t.b->t.b)
 300                 g_assert_not_reached();
 301
 302         RoamTriangle *base = self->t.b;
 303
 304         /* Add new triangles */
 305         RoamPoint *mid = self->split;
 306         RoamTriangle *sl = self->kids[0] = roam_triangle_new(self->p.m, mid, self->p.l); // Self Left
 307         RoamTriangle *sr = self->kids[1] = roam_triangle_new(self->p.r, mid, self->p.m); // Self Right
 308         RoamTriangle *bl = base->kids[0] = roam_triangle_new(base->p.m, mid, base->p.l); // Base Left
 309         RoamTriangle *br = base->kids[1] = roam_triangle_new(base->p.r, mid, base->p.m); // Base Right
 310
 311         /*                tri,l,  base,      r,  sphere */
 312         roam_triangle_add(sl, sr, self->t.l, br, sphere);
 313         roam_triangle_add(sr, bl, self->t.r, sl, sphere);
 314         roam_triangle_add(bl, br, base->t.l, sr, sphere);
 315         roam_triangle_add(br, sl, base->t.r, bl, sphere);
 316
 317         roam_triangle_sync_neighbors(sl, self, self->t.l);
 318         roam_triangle_sync_neighbors(sr, self, self->t.r);
 319         roam_triangle_sync_neighbors(bl, base, base->t.l);
 320         roam_triangle_sync_neighbors(br, base, base->t.r);
 321
 322         /* Remove old triangles */
 323         roam_triangle_remove(self, sphere);
 324         roam_triangle_remove(base, sphere);
 325
 326         /* Add/Remove diamonds */
 327         RoamDiamond *diamond = roam_diamond_new(self, base, sl, sr, bl, br);
 328         roam_diamond_update_errors(diamond, sphere);
 329         roam_diamond_add(diamond, sphere);
 330         roam_diamond_remove(self->parent, sphere);
 331         roam_diamond_remove(base->parent, sphere);
 332 }
 333
 334 void roam_triangle_draw(RoamTriangle *self)
 335 {
 336         glBegin(GL_TRIANGLES);
 337         glNormal3dv(self->p.r->norm); glVertex3dv((double*)self->p.r);
 338         glNormal3dv(self->p.m->norm); glVertex3dv((double*)self->p.m);
 339         glNormal3dv(self->p.l->norm); glVertex3dv((double*)self->p.l);
 340         glEnd();
 341         return;
 342 }
 343
 344 void roam_triangle_draw_normal(RoamTriangle *self)
 345 {
 346         double center[] = {
 347                 (self->p.l->x + self->p.m->x + self->p.r->x)/3.0,
 348                 (self->p.l->y + self->p.m->y + self->p.r->y)/3.0,
 349                 (self->p.l->z + self->p.m->z + self->p.r->z)/3.0,
 350         };
 351         double end[] = {
 352                 center[0]+self->norm[0]*2000000,
 353                 center[1]+self->norm[1]*2000000,
 354                 center[2]+self->norm[2]*2000000,
 355         };
 356         glBegin(GL_LINES);
 357         glVertex3dv(center);
 358         glVertex3dv(end);
 359         glEnd();
 360 }
 361
 362 /***************
 363  * RoamDiamond *
 364  ***************/
 365 RoamDiamond *roam_diamond_new(
 366                 RoamTriangle *parent0, RoamTriangle *parent1,
 367                 RoamTriangle *kid0, RoamTriangle *kid1,
 368                 RoamTriangle *kid2, RoamTriangle *kid3)
 369 {
 370         RoamDiamond *self = g_new0(RoamDiamond, 1);
 371
 372         self->kids[0] = kid0;
 373         self->kids[1] = kid1;
 374         self->kids[2] = kid2;
 375         self->kids[3] = kid3;
 376
 377         kid0->parent = self;
 378         kid1->parent = self;
 379         kid2->parent = self;
 380         kid3->parent = self;
 381
 382         self->parents[0] = parent0;
 383         self->parents[1] = parent1;
 384
 385         return self;
 386 }
 387 void roam_diamond_add(RoamDiamond *self, RoamSphere *sphere)
 388 {
 389         self->active = TRUE;
 390         self->error  = MAX(self->parents[0]->error, self->parents[1]->error);
 391         self->handle = g_pqueue_push(sphere->diamonds, self);
 392 }
 393 void roam_diamond_remove(RoamDiamond *self, RoamSphere *sphere)
 394 {
 395         if (self && self->active) {
 396                 self->active = FALSE;
 397                 g_pqueue_remove(sphere->diamonds, self->handle);
 398         }
 399 }
 400 void roam_diamond_merge(RoamDiamond *self, RoamSphere *sphere)
 401 {
 402         //g_message("roam_diamond_merge: %p, e=%f\n", self, self->error);
 403
 404         sphere->polys -= 2;
 405
 406         /* TODO: pick the best split */
 407         RoamTriangle **kids = self->kids;
 408
 409         /* Create triangles */
 410         RoamTriangle *tri  = self->parents[0];
 411         RoamTriangle *base = self->parents[1];
 412
 413         roam_triangle_add(tri,  kids[0]->t.b, base, kids[1]->t.b, sphere);
 414         roam_triangle_add(base, kids[2]->t.b, tri,  kids[3]->t.b, sphere);
 415
 416         roam_triangle_sync_neighbors(tri,  kids[0], kids[0]->t.b);
 417         roam_triangle_sync_neighbors(tri,  kids[1], kids[1]->t.b);
 418         roam_triangle_sync_neighbors(base, kids[2], kids[2]->t.b);
 419         roam_triangle_sync_neighbors(base, kids[3], kids[3]->t.b);
 420
 421         /* Remove triangles */
 422         roam_triangle_remove(kids[0], sphere);
 423         roam_triangle_remove(kids[1], sphere);
 424         roam_triangle_remove(kids[2], sphere);
 425         roam_triangle_remove(kids[3], sphere);
 426
 427         /* Clear kids */
 428         tri->kids[0]  = tri->kids[1]  = NULL;
 429         base->kids[0] = base->kids[1] = NULL;
 430
 431         /* Add/Remove triangles */
 432         if (tri->t.l->t.l == tri->t.r->t.r &&
 433             tri->t.l->t.l != tri && tri->parent) {
 434                 roam_diamond_update_errors(tri->parent, sphere);
 435                 roam_diamond_add(tri->parent, sphere);
 436         }
 437
 438         if (base->t.l->t.l == base->t.r->t.r &&
 439             base->t.l->t.l != base && base->parent) {
 440                 roam_diamond_update_errors(base->parent, sphere);
 441                 roam_diamond_add(base->parent, sphere);
 442         }
 443
 444         /* Remove and free diamond and child triangles */
 445         roam_diamond_remove(self, sphere);
 446         g_assert(self->kids[0]->p.m == self->kids[1]->p.m &&
 447                  self->kids[1]->p.m == self->kids[2]->p.m &&
 448                  self->kids[2]->p.m == self->kids[3]->p.m);
 449         g_assert(self->kids[0]->p.m->tris == 0);
 450         roam_triangle_free(self->kids[0]);
 451         roam_triangle_free(self->kids[1]);
 452         roam_triangle_free(self->kids[2]);
 453         roam_triangle_free(self->kids[3]);
 454         g_free(self);
 455 }
 456 void roam_diamond_update_errors(RoamDiamond *self, RoamSphere *sphere)
 457 {
 458         roam_triangle_update_errors(self->parents[0], sphere);
 459         roam_triangle_update_errors(self->parents[1], sphere);
 460         self->error = MAX(self->parents[0]->error, self->parents[1]->error);
 461 }
 462
 463 /**************
 464  * RoamSphere *
 465  **************/
 466 RoamSphere *roam_sphere_new()
 467 {
 468         RoamSphere *self = g_new0(RoamSphere, 1);
 469         self->polys       = 8;
 470         self->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 471         self->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 472
 473         RoamPoint *vertexes[] = {
 474                 roam_point_new( 90,   0,  0), // 0 (North)
 475                 roam_point_new(-90,   0,  0), // 1 (South)
 476                 roam_point_new(  0,   0,  0), // 2 (Europe/Africa)
 477                 roam_point_new(  0,  90,  0), // 3 (Asia,East)
 478                 roam_point_new(  0, 180,  0), // 4 (Pacific)
 479                 roam_point_new(  0, -90,  0), // 5 (Americas,West)
 480         };
 481         int _triangles[][2][3] = {
 482                 /*lv mv rv   ln, bn, rn */
 483                 {{2,0,3}, {3, 4, 1}}, // 0
 484                 {{3,0,4}, {0, 5, 2}}, // 1
 485                 {{4,0,5}, {1, 6, 3}}, // 2
 486                 {{5,0,2}, {2, 7, 0}}, // 3
 487                 {{3,1,2}, {5, 0, 7}}, // 4
 488                 {{4,1,3}, {6, 1, 4}}, // 5
 489                 {{5,1,4}, {7, 2, 5}}, // 6
 490                 {{2,1,5}, {4, 3, 6}}, // 7
 491         };
 492
 493         for (int i = 0; i < 6; i++)
 494                 roam_point_update_height(vertexes[i]);
 495         for (int i = 0; i < 8; i++)
 496                 self->roots[i] = roam_triangle_new(
 497                         vertexes[_triangles[i][0][0]],
 498                         vertexes[_triangles[i][0][1]],
 499                         vertexes[_triangles[i][0][2]]);
 500         for (int i = 0; i < 8; i++)
 501                 roam_triangle_add(self->roots[i],
 502                         self->roots[_triangles[i][1][0]],
 503                         self->roots[_triangles[i][1][1]],
 504                         self->roots[_triangles[i][1][2]],
 505                         self);
 506         for (int i = 0; i < 8; i++)
 507                 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", self->roots[i],
 508                                 self->roots[i]->edge.n,
 509                                 self->roots[i]->edge.s,
 510                                 self->roots[i]->edge.e,
 511                                 self->roots[i]->edge.w);
 512
 513         return self;
 514 }
 515 void roam_sphere_update_view(RoamSphere *self)
 516 {
 517         if (!self->view)
 518                 self->view = g_new0(RoamView, 1);
 519         glGetDoublev (GL_MODELVIEW_MATRIX,  self->view->model);
 520         glGetDoublev (GL_PROJECTION_MATRIX, self->view->proj);
 521         glGetIntegerv(GL_VIEWPORT,          self->view->view);
 522         self->view->version++;
 523 }
 524 void roam_sphere_update_errors(RoamSphere *self)
 525 {
 526         g_debug("RoamSphere: update_errors - polys=%d", self->polys);
 527         GPtrArray *tris = g_pqueue_get_array(self->triangles);
 528         GPtrArray *dias = g_pqueue_get_array(self->diamonds);
 529
 530         roam_sphere_update_view(self);
 531
 532         for (int i = 0; i < tris->len; i++) {
 533                 RoamTriangle *tri = tris->pdata[i];
 534                 roam_triangle_update_errors(tri, self);
 535                 g_pqueue_priority_changed(self->triangles, tri->handle);
 536         }
 537
 538         for (int i = 0; i < dias->len; i++) {
 539                 RoamDiamond *dia = dias->pdata[i];
 540                 roam_diamond_update_errors(dia, self);
 541                 g_pqueue_priority_changed(self->diamonds, dia->handle);
 542         }
 543
 544         g_ptr_array_free(tris, TRUE);
 545         g_ptr_array_free(dias, TRUE);
 546 }
 547
 548 void roam_sphere_split_one(RoamSphere *self)
 549 {
 550         RoamTriangle *to_split = g_pqueue_peek(self->triangles);
 551         if (!to_split) return;
 552         roam_triangle_split(to_split, self);
 553 }
 554 void roam_sphere_merge_one(RoamSphere *self)
 555 {
 556         RoamDiamond *to_merge = g_pqueue_peek(self->diamonds);
 557         if (!to_merge) return;
 558         roam_diamond_merge(to_merge, self);
 559 }
 560 gint roam_sphere_split_merge(RoamSphere *self)
 561 {
 562         gint iters = 0, max_iters = 500;
 563         //gint target = 4000;
 564         gint target = 2000;
 565         //gint target = 500;
 566
 567         if (!self->view)
 568                 return 0;
 569
 570         if (target - self->polys > 100) {
 571                 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, self->polys);
 572                 while (self->polys < target && iters++ < max_iters)
 573                         roam_sphere_split_one(self);
 574         }
 575
 576         if (self->polys - target > 100) {
 577                 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", self->polys, target);
 578                 while (self->polys > target && iters++ < max_iters)
 579                         roam_sphere_merge_one(self);
 580         }
 581
 582         while (((RoamTriangle*)g_pqueue_peek(self->triangles))->error >
 583                ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error &&
 584                iters++ < max_iters) {
 585                 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
 586                 //              ((RoamTriangle*)g_pqueue_peek(self->triangles))->error,
 587                 //              ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error,
 588                 //              iters-1, max_iters);
 589                 roam_sphere_merge_one(self);
 590                 roam_sphere_split_one(self);
 591         }
 592
 593         return iters;
 594 }
 595 void roam_sphere_draw(RoamSphere *self)
 596 {
 597         g_debug("RoamSphere: draw");
 598         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw, NULL);
 599 }
 600 void roam_sphere_draw_normals(RoamSphere *self)
 601 {
 602         g_debug("RoamSphere: draw_normal");
 603         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 604 }
 605 static GList *_roam_sphere_get_leaves(RoamTriangle *tri, GList *list, gboolean all)
 606 {
 607         if (tri->kids[0] && tri->kids[1]) {
 608                 if (all) list = g_list_prepend(list, tri);
 609                 list = _roam_sphere_get_leaves(tri->kids[0], list, all);
 610                 list = _roam_sphere_get_leaves(tri->kids[1], list, all);
 611                 return list;
 612         } else {
 613                 return g_list_prepend(list, tri);
 614         }
 615 }
 616 static GList *_roam_sphere_get_intersect_rec(RoamTriangle *tri, GList *list,
 617                 gboolean all, gdouble n, gdouble s, gdouble e, gdouble w)
 618 {
 619         gdouble tn = tri->edge.n;
 620         gdouble ts = tri->edge.s;
 621         gdouble te = tri->edge.e;
 622         gdouble tw = tri->edge.w;
 623
 624         gboolean debug = FALSE  &&
 625                 n==90 && s==45 && e==-90 && w==-180 &&
 626                 ts > 44 && ts < 46;
 627
 628         if (debug)
 629                 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
 630                             tri, tn,   s,   ts,   n,   te,   w,   tw,   e);
 631         if (tn < s || ts > n || te < w || tw > e) {
 632                 /* No intersect */
 633                 if (debug) g_message("no intersect");
 634                 return list;
 635         } else if (tn <= n && ts >= s && te <= e && tw >= w) {
 636                 /* Triangle is completely contained */
 637                 if (debug) g_message("contained");
 638                 if (all) list = g_list_prepend(list, tri);
 639                 return _roam_sphere_get_leaves(tri, list, all);
 640         } else if (tri->kids[0] && tri->kids[1]) {
 641                 /* Paritial intersect with children */
 642                 if (debug) g_message("edge w/ child");
 643                 if (all) list = g_list_prepend(list, tri);
 644                 list = _roam_sphere_get_intersect_rec(tri->kids[0], list, all, n, s, e, w);
 645                 list = _roam_sphere_get_intersect_rec(tri->kids[1], list, all, n, s, e, w);
 646                 return list;
 647         } else {
 648                 /* This triangle is an edge case */
 649                 if (debug) g_message("edge");
 650                 return g_list_prepend(list, tri);
 651         }
 652 }
 653 /* Warning: This grabs pointers to triangles which can be changed by other
 654  * calls, e.g. split_merge. If you use this, you need to do some locking to
 655  * prevent the returned list from becomming stale. */
 656 GList *roam_sphere_get_intersect(RoamSphere *self, gboolean all,
 657                 gdouble n, gdouble s, gdouble e, gdouble w)
 658 {
 659         /* I think this is correct..
 660          * i_cost = cost for triangle-rectagnle intersect test
 661          * time = n_tiles * 2*tris_per_tile * i_cost
 662          * time = 30      * 2*333           * i_cost = 20000 * i_cost */
 663         GList *list = NULL;
 664         for (int i = 0; i < G_N_ELEMENTS(self->roots); i++)
 665                 list = _roam_sphere_get_intersect_rec(self->roots[i],
 666                                 list, all, n, s, e, w);
 667         return list;
 668 }
 669 void roam_sphere_free_tri(RoamTriangle *tri)
 670 {
 671         if (--tri->p.l->tris == 0) g_free(tri->p.l);
 672         if (--tri->p.m->tris == 0) g_free(tri->p.m);
 673         if (--tri->p.r->tris == 0) g_free(tri->p.r);
 674         roam_triangle_free(tri);
 675 }
 676 void roam_sphere_free(RoamSphere *self)
 677 {
 678         /* Slow method, but it should work */
 679         while (self->polys > 8)
 680                 roam_sphere_merge_one(self);
 681         /* TODO: free points */
 682         g_pqueue_foreach(self->triangles, (GFunc)roam_sphere_free_tri, NULL);
 683         g_pqueue_free(self->triangles);
 684         g_pqueue_free(self->diamonds);
 685         g_free(self->view);
 686         g_free(self);
 687 }