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

   1 /*
   2  * Copyright (C) 2009 Andy Spencer <spenceal@rose-hulman.edu>
   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  * RoamPoint *
  51  *************/
  52 RoamPoint *roam_point_new(gdouble x, gdouble y, gdouble z)
  53 {
  54         RoamPoint *self = g_new0(RoamPoint, 1);
  55         self->x = x;
  56         self->y = y;
  57         self->z = z;
  58         /* For get_intersect */
  59         xyz2ll(x, y, z, &self->lat, &self->lon);
  60         return self;
  61 }
  62 RoamPoint *roam_point_dup(RoamPoint *self)
  63 {
  64         RoamPoint *new = g_memdup(self, sizeof(RoamPoint));
  65         new->tris = 0;
  66         return new;
  67 }
  68 void roam_point_add_triangle(RoamPoint *self, RoamTriangle *triangle)
  69 {
  70         for (int i = 0; i < 3; i++) {
  71                 self->norm[i] *= self->tris;
  72                 self->norm[i] += triangle->norm[i];
  73         }
  74         self->tris++;
  75         for (int i = 0; i < 3; i++)
  76                 self->norm[i] /= self->tris;
  77 }
  78 void roam_point_remove_triangle(RoamPoint *self, RoamTriangle *triangle)
  79 {
  80         for (int i = 0; i < 3; i++) {
  81                 self->norm[i] *= self->tris;
  82                 self->norm[i] -= triangle->norm[i];
  83         }
  84         self->tris--;
  85         if (self->tris)
  86                 for (int i = 0; i < 3; i++)
  87                         self->norm[i] /= self->tris;
  88 }
  89 void roam_point_update_height(RoamPoint *self)
  90 {
  91         if (self->height_func) {
  92                 gdouble elev = self->height_func(
  93                                 self->lat, self->lon, self->height_data);
  94                 lle2xyz(self->lat, self->lon, elev,
  95                                 &self->x, &self->y, &self->z);
  96         } else {
  97                 gdouble dist = sqrt(self->x * self->x +
  98                                     self->y * self->y +
  99                                     self->z * self->z);
 100                 self->x = self->x/dist * EARTH_R;
 101                 self->y = self->y/dist * EARTH_R;
 102                 self->z = self->z/dist * EARTH_R;
 103         }
 104 }
 105 void roam_point_update_projection(RoamPoint *self, RoamSphere *sphere)
 106 {
 107         static int count   = 0;
 108         static int version = 0;
 109         if (version != sphere->view->version) {
 110                 g_debug("Projected %d points", count);
 111                 count   = 0;
 112                 version = sphere->view->version;
 113         }
 114
 115         if (self->pversion != sphere->view->version) {
 116                 /* Cache projection */
 117                 gluProject(self->x, self->y, self->z,
 118                         sphere->view->model, sphere->view->proj, sphere->view->view,
 119                         &self->px, &self->py, &self->pz);
 120                 self->pversion = sphere->view->version;
 121                 count++;
 122         }
 123 }
 124
 125 /****************
 126  * RoamTriangle *
 127  ****************/
 128 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
 129 {
 130         RoamTriangle *self = g_new0(RoamTriangle, 1);
 131
 132         self->error = 0;
 133         self->p.l = l;
 134         self->p.m = m;
 135         self->p.r = r;
 136         self->split = roam_point_new(
 137                 (l->x + r->x)/2,
 138                 (l->y + r->y)/2,
 139                 (l->z + r->z)/2);
 140         /* TODO: Move this back to sphere, or actually use the nesting */
 141         self->split->height_func = m->height_func;
 142         self->split->height_data = m->height_data;
 143         roam_point_update_height(self->split);
 144         //if ((float)self->split->lat > 44 && (float)self->split->lat < 46)
 145         //      g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
 146         //                      l->lat, m->lat, r->lat, self->split->lat);
 147         //if ((float)l->lat == (float)r->lat &&
 148         //    (float)self->split->lat != (float)l->lat)
 149         //      g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
 150         //              self->split->lat, l->lat);
 151
 152         /* Update normal */
 153         double pa[3];
 154         double pb[3];
 155         pa[0] = self->p.l->x - self->p.m->x;
 156         pa[1] = self->p.l->y - self->p.m->y;
 157         pa[2] = self->p.l->z - self->p.m->z;
 158
 159         pb[0] = self->p.r->x - self->p.m->x;
 160         pb[1] = self->p.r->y - self->p.m->y;
 161         pb[2] = self->p.r->z - self->p.m->z;
 162
 163         self->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 164         self->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 165         self->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 166
 167         double total = sqrt(self->norm[0] * self->norm[0] +
 168                             self->norm[1] * self->norm[1] +
 169                             self->norm[2] * self->norm[2]);
 170
 171         self->norm[0] /= total;
 172         self->norm[1] /= total;
 173         self->norm[2] /= total;
 174
 175         /* Store bounding box, for get_intersect */
 176         RoamPoint *m1 = roam_point_new((l->x+m->x)/2, (l->y+m->y)/2, (l->z+m->z)/2);
 177         RoamPoint *m2 = roam_point_new((m->x+r->x)/2, (m->y+r->y)/2, (m->z+r->z)/2);
 178         RoamPoint *m3 = roam_point_new((r->x+l->x)/2, (r->y+l->y)/2, (r->z+l->z)/2);
 179         RoamPoint *p[] = {l,m,r,m1,m2,m3};
 180         self->edge.n =  -90; self->edge.s =  90;
 181         self->edge.e = -180; self->edge.w = 180;
 182         gboolean maxed = FALSE;
 183         for (int i = 0; i < G_N_ELEMENTS(p); i++) {
 184                 self->edge.n = MAX(self->edge.n, p[i]->lat);
 185                 self->edge.s = MIN(self->edge.s, p[i]->lat);
 186                 if (p[i]->lat == 90 || p[i]->lat == -90)
 187                         continue;
 188                 if (p[i]->lon == 180) {
 189                         maxed = TRUE;
 190                         continue;
 191                 }
 192                 self->edge.e = MAX(self->edge.e, p[i]->lon);
 193                 self->edge.w = MIN(self->edge.w, p[i]->lon);
 194         }
 195         if (maxed) {
 196                 if (self->edge.e < 0)
 197                         self->edge.w = -180;
 198                 else
 199                         self->edge.e =  180;
 200         }
 201         g_free(m1);
 202         g_free(m2);
 203         g_free(m3);
 204
 205         //g_message("roam_triangle_new: %p", self);
 206         return self;
 207 }
 208
 209 void roam_triangle_free(RoamTriangle *self)
 210 {
 211         g_free(self->split);
 212         g_free(self);
 213 }
 214
 215 void roam_triangle_add(RoamTriangle *self,
 216                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 217                 RoamSphere *sphere)
 218 {
 219         self->t.l = left;
 220         self->t.b = base;
 221         self->t.r = right;
 222
 223         roam_point_add_triangle(self->p.l, self);
 224         roam_point_add_triangle(self->p.m, self);
 225         roam_point_add_triangle(self->p.r, self);
 226
 227         if (sphere->view)
 228                 roam_triangle_update_errors(self, sphere);
 229
 230         self->handle = g_pqueue_push(sphere->triangles, self);
 231 }
 232
 233 void roam_triangle_remove(RoamTriangle *self, RoamSphere *sphere)
 234 {
 235         /* Update vertex normals */
 236         roam_point_remove_triangle(self->p.l, self);
 237         roam_point_remove_triangle(self->p.m, self);
 238         roam_point_remove_triangle(self->p.r, self);
 239
 240         g_pqueue_remove(sphere->triangles, self->handle);
 241 }
 242
 243 void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
 244 {
 245         if      (neigh->t.l == old) neigh->t.l = new;
 246         else if (neigh->t.b == old) neigh->t.b = new;
 247         else if (neigh->t.r == old) neigh->t.r = new;
 248         else g_assert_not_reached();
 249 }
 250
 251 gboolean roam_point_visible(RoamPoint *self, RoamSphere *sphere)
 252 {
 253         gint *view = sphere->view->view;
 254         return self->px > view[0] && self->px < view[2] &&
 255                self->py > view[1] && self->py < view[3] &&
 256                self->pz > 0       && self->pz < 1;
 257 }
 258 gboolean roam_triangle_visible(RoamTriangle *self, RoamSphere *sphere)
 259 {
 260         /* Do this with a bounding box */
 261         return roam_point_visible(self->p.l, sphere) ||
 262                roam_point_visible(self->p.m, sphere) ||
 263                roam_point_visible(self->p.r, sphere);
 264 }
 265
 266 void roam_triangle_update_errors(RoamTriangle *self, RoamSphere *sphere)
 267 {
 268         /* Update points */
 269         roam_point_update_projection(self->p.l, sphere);
 270         roam_point_update_projection(self->p.m, sphere);
 271         roam_point_update_projection(self->p.r, sphere);
 272
 273         /* Not exactly correct, could be out on both sides (middle in) */
 274         if (!roam_triangle_visible(self, sphere)) {
 275                 self->error = -1;
 276         } else {
 277                 roam_point_update_projection(self->split, sphere);
 278                 RoamPoint *l = self->p.l;
 279                 RoamPoint *m = self->p.m;
 280                 RoamPoint *r = self->p.r;
 281                 RoamPoint *split = self->split;
 282
 283                 /*               l-r midpoint        projected l-r midpoint */
 284                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 285                 gdouble pydist = (l->py + r->py)/2 - split->py;
 286
 287                 self->error = sqrt(pxdist*pxdist + pydist*pydist);
 288
 289                 /* Multiply by size of triangle */
 290                 double size = -( l->px * (m->py - r->py) +
 291                                  m->px * (r->py - l->py) +
 292                                  r->px * (l->py - m->py) ) / 2.0;
 293
 294                 /* Size < 0 == backface */
 295                 //if (size < 0)
 296                 //      self->error *= -1;
 297                 self->error *= size;
 298         }
 299 }
 300
 301 void roam_triangle_split(RoamTriangle *self, RoamSphere *sphere)
 302 {
 303         //g_message("roam_triangle_split: %p, e=%f\n", self, self->error);
 304
 305         sphere->polys += 2;
 306
 307         if (self != self->t.b->t.b)
 308                 roam_triangle_split(self->t.b, sphere);
 309
 310         RoamTriangle *base = self->t.b;
 311
 312         /* Add new triangles */
 313         RoamPoint *mid = self->split;
 314         RoamTriangle *sl = self->kids[0] = roam_triangle_new(self->p.m, mid, self->p.l); // Self Left
 315         RoamTriangle *sr = self->kids[1] = roam_triangle_new(self->p.r, mid, self->p.m); // Self Right
 316         RoamTriangle *bl = base->kids[0] = roam_triangle_new(base->p.m, mid, base->p.l); // Base Left
 317         RoamTriangle *br = base->kids[1] = roam_triangle_new(base->p.r, mid, base->p.m); // Base Right
 318
 319         /*                tri,l,  base,      r,  sphere */
 320         roam_triangle_add(sl, sr, self->t.l, br, sphere);
 321         roam_triangle_add(sr, bl, self->t.r, sl, sphere);
 322         roam_triangle_add(bl, br, base->t.l, sr, sphere);
 323         roam_triangle_add(br, sl, base->t.r, bl, sphere);
 324
 325         roam_triangle_sync_neighbors(sl, self, self->t.l);
 326         roam_triangle_sync_neighbors(sr, self, self->t.r);
 327         roam_triangle_sync_neighbors(bl, base, base->t.l);
 328         roam_triangle_sync_neighbors(br, base, base->t.r);
 329
 330         /* Remove old triangles */
 331         roam_triangle_remove(self, sphere);
 332         roam_triangle_remove(base, sphere);
 333
 334         /* Add/Remove diamonds */
 335         RoamDiamond *diamond = roam_diamond_new(self, base, sl, sr, bl, br);
 336         roam_diamond_update_errors(diamond, sphere);
 337         roam_diamond_add(diamond, sphere);
 338         roam_diamond_remove(self->parent, sphere);
 339         roam_diamond_remove(base->parent, sphere);
 340 }
 341
 342 void roam_triangle_draw(RoamTriangle *self)
 343 {
 344         glBegin(GL_TRIANGLES);
 345         glNormal3dv(self->p.r->norm); glVertex3dv((double*)self->p.r);
 346         glNormal3dv(self->p.m->norm); glVertex3dv((double*)self->p.m);
 347         glNormal3dv(self->p.l->norm); glVertex3dv((double*)self->p.l);
 348         glEnd();
 349         return;
 350 }
 351
 352 void roam_triangle_draw_normal(RoamTriangle *self)
 353 {
 354         double center[] = {
 355                 (self->p.l->x + self->p.m->x + self->p.r->x)/3.0,
 356                 (self->p.l->y + self->p.m->y + self->p.r->y)/3.0,
 357                 (self->p.l->z + self->p.m->z + self->p.r->z)/3.0,
 358         };
 359         double end[] = {
 360                 center[0]+self->norm[0]*2000000,
 361                 center[1]+self->norm[1]*2000000,
 362                 center[2]+self->norm[2]*2000000,
 363         };
 364         glBegin(GL_LINES);
 365         glVertex3dv(center);
 366         glVertex3dv(end);
 367         glEnd();
 368 }
 369
 370 /***************
 371  * RoamDiamond *
 372  ***************/
 373 RoamDiamond *roam_diamond_new(
 374                 RoamTriangle *parent0, RoamTriangle *parent1,
 375                 RoamTriangle *kid0, RoamTriangle *kid1,
 376                 RoamTriangle *kid2, RoamTriangle *kid3)
 377 {
 378         RoamDiamond *self = g_new0(RoamDiamond, 1);
 379
 380         self->kids[0] = kid0;
 381         self->kids[1] = kid1;
 382         self->kids[2] = kid2;
 383         self->kids[3] = kid3;
 384
 385         kid0->parent = self;
 386         kid1->parent = self;
 387         kid2->parent = self;
 388         kid3->parent = self;
 389
 390         self->parents[0] = parent0;
 391         self->parents[1] = parent1;
 392
 393         return self;
 394 }
 395 void roam_diamond_add(RoamDiamond *self, RoamSphere *sphere)
 396 {
 397         self->active = TRUE;
 398         self->error  = MAX(self->parents[0]->error, self->parents[1]->error);
 399         self->handle = g_pqueue_push(sphere->diamonds, self);
 400 }
 401 void roam_diamond_remove(RoamDiamond *self, RoamSphere *sphere)
 402 {
 403         if (self && self->active) {
 404                 self->active = FALSE;
 405                 g_pqueue_remove(sphere->diamonds, self->handle);
 406         }
 407 }
 408 void roam_diamond_merge(RoamDiamond *self, RoamSphere *sphere)
 409 {
 410         //g_message("roam_diamond_merge: %p, e=%f\n", self, self->error);
 411
 412         sphere->polys -= 2;
 413
 414         /* TODO: pick the best split */
 415         RoamTriangle **kids = self->kids;
 416
 417         /* Create triangles */
 418         RoamTriangle *tri  = self->parents[0];
 419         RoamTriangle *base = self->parents[1];
 420
 421         roam_triangle_add(tri,  kids[0]->t.b, base, kids[1]->t.b, sphere);
 422         roam_triangle_add(base, kids[2]->t.b, tri,  kids[3]->t.b, sphere);
 423
 424         roam_triangle_sync_neighbors(tri,  kids[0], kids[0]->t.b);
 425         roam_triangle_sync_neighbors(tri,  kids[1], kids[1]->t.b);
 426         roam_triangle_sync_neighbors(base, kids[2], kids[2]->t.b);
 427         roam_triangle_sync_neighbors(base, kids[3], kids[3]->t.b);
 428
 429         /* Remove triangles */
 430         roam_triangle_remove(kids[0], sphere);
 431         roam_triangle_remove(kids[1], sphere);
 432         roam_triangle_remove(kids[2], sphere);
 433         roam_triangle_remove(kids[3], sphere);
 434
 435         /* Clear kids */
 436         tri->kids[0]  = tri->kids[1]  = NULL;
 437         base->kids[0] = base->kids[1] = NULL;
 438
 439         /* Add/Remove triangles */
 440         if (tri->t.l->t.l == tri->t.r->t.r &&
 441             tri->t.l->t.l != tri && tri->parent) {
 442                 roam_diamond_update_errors(tri->parent, sphere);
 443                 roam_diamond_add(tri->parent, sphere);
 444         }
 445
 446         if (base->t.l->t.l == base->t.r->t.r &&
 447             base->t.l->t.l != base && base->parent) {
 448                 roam_diamond_update_errors(base->parent, sphere);
 449                 roam_diamond_add(base->parent, sphere);
 450         }
 451
 452         /* Remove and free diamond and child triangles */
 453         roam_diamond_remove(self, sphere);
 454         g_assert(self->kids[0]->p.m == self->kids[1]->p.m &&
 455                  self->kids[1]->p.m == self->kids[2]->p.m &&
 456                  self->kids[2]->p.m == self->kids[3]->p.m);
 457         g_assert(self->kids[0]->p.m->tris == 0);
 458         roam_triangle_free(self->kids[0]);
 459         roam_triangle_free(self->kids[1]);
 460         roam_triangle_free(self->kids[2]);
 461         roam_triangle_free(self->kids[3]);
 462         g_free(self);
 463 }
 464 void roam_diamond_update_errors(RoamDiamond *self, RoamSphere *sphere)
 465 {
 466         roam_triangle_update_errors(self->parents[0], sphere);
 467         roam_triangle_update_errors(self->parents[1], sphere);
 468         self->error = MAX(self->parents[0]->error, self->parents[1]->error);
 469 }
 470
 471 /**************
 472  * RoamSphere *
 473  **************/
 474 RoamSphere *roam_sphere_new()
 475 {
 476         RoamSphere *self = g_new0(RoamSphere, 1);
 477         self->polys       = 8;
 478         self->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 479         self->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 480
 481         RoamPoint *vertexes[] = {
 482                 roam_point_new( 0, 1, 0), // 0
 483                 roam_point_new( 0,-1, 0), // 1
 484                 roam_point_new( 0, 0, 1), // 2
 485                 roam_point_new( 1, 0, 0), // 3
 486                 roam_point_new( 0, 0,-1), // 4
 487                 roam_point_new(-1, 0, 0), // 5
 488         };
 489         int _triangles[][2][3] = {
 490                 /*lv mv rv   ln, bn, rn */
 491                 {{2,0,3}, {3, 4, 1}}, // 0
 492                 {{3,0,4}, {0, 5, 2}}, // 1
 493                 {{4,0,5}, {1, 6, 3}}, // 2
 494                 {{5,0,2}, {2, 7, 0}}, // 3
 495                 {{3,1,2}, {5, 0, 7}}, // 4
 496                 {{4,1,3}, {6, 1, 4}}, // 5
 497                 {{5,1,4}, {7, 2, 5}}, // 6
 498                 {{2,1,5}, {4, 3, 6}}, // 7
 499         };
 500
 501         for (int i = 0; i < 6; i++)
 502                 roam_point_update_height(vertexes[i]);
 503         for (int i = 0; i < 8; i++)
 504                 self->roots[i] = roam_triangle_new(
 505                         vertexes[_triangles[i][0][0]],
 506                         vertexes[_triangles[i][0][1]],
 507                         vertexes[_triangles[i][0][2]]);
 508         for (int i = 0; i < 8; i++)
 509                 roam_triangle_add(self->roots[i],
 510                         self->roots[_triangles[i][1][0]],
 511                         self->roots[_triangles[i][1][1]],
 512                         self->roots[_triangles[i][1][2]],
 513                         self);
 514         for (int i = 0; i < 8; i++)
 515                 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", self->roots[i],
 516                                 self->roots[i]->edge.n,
 517                                 self->roots[i]->edge.s,
 518                                 self->roots[i]->edge.e,
 519                                 self->roots[i]->edge.w);
 520
 521         return self;
 522 }
 523 void roam_sphere_update_view(RoamSphere *self)
 524 {
 525         if (!self->view)
 526                 self->view = g_new0(RoamView, 1);
 527         glGetDoublev (GL_MODELVIEW_MATRIX,  self->view->model);
 528         glGetDoublev (GL_PROJECTION_MATRIX, self->view->proj);
 529         glGetIntegerv(GL_VIEWPORT,          self->view->view);
 530         self->view->version++;
 531 }
 532 void roam_sphere_update_errors(RoamSphere *self)
 533 {
 534         g_debug("RoamSphere: update_errors - polys=%d", self->polys);
 535         GPtrArray *tris = g_pqueue_get_array(self->triangles);
 536         GPtrArray *dias = g_pqueue_get_array(self->diamonds);
 537
 538         roam_sphere_update_view(self);
 539
 540         for (int i = 0; i < tris->len; i++) {
 541                 RoamTriangle *tri = tris->pdata[i];
 542                 roam_triangle_update_errors(tri, self);
 543                 g_pqueue_priority_changed(self->triangles, tri->handle);
 544         }
 545
 546         for (int i = 0; i < dias->len; i++) {
 547                 RoamDiamond *dia = dias->pdata[i];
 548                 roam_diamond_update_errors(dia, self);
 549                 g_pqueue_priority_changed(self->diamonds, dia->handle);
 550         }
 551
 552         g_ptr_array_free(tris, TRUE);
 553         g_ptr_array_free(dias, TRUE);
 554 }
 555
 556 void roam_sphere_split_one(RoamSphere *self)
 557 {
 558         RoamTriangle *to_split = g_pqueue_peek(self->triangles);
 559         if (!to_split) return;
 560         roam_triangle_split(to_split, self);
 561 }
 562 void roam_sphere_merge_one(RoamSphere *self)
 563 {
 564         RoamDiamond *to_merge = g_pqueue_peek(self->diamonds);
 565         if (!to_merge) return;
 566         roam_diamond_merge(to_merge, self);
 567 }
 568 gint roam_sphere_split_merge(RoamSphere *self)
 569 {
 570         gint iters = 0, max_iters = 500;
 571         //gint target = 4000;
 572         gint target = 2000;
 573         //gint target = 500;
 574
 575         if (!self->view)
 576                 return 0;
 577
 578         if (target - self->polys > 100) {
 579                 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, self->polys);
 580                 while (self->polys < target && iters++ < max_iters)
 581                         roam_sphere_split_one(self);
 582         }
 583
 584         if (self->polys - target > 100) {
 585                 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", self->polys, target);
 586                 while (self->polys > target && iters++ < max_iters)
 587                         roam_sphere_merge_one(self);
 588         }
 589
 590         while (((RoamTriangle*)g_pqueue_peek(self->triangles))->error >
 591                ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error &&
 592                iters++ < max_iters) {
 593                 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
 594                 //              ((RoamTriangle*)g_pqueue_peek(self->triangles))->error,
 595                 //              ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error,
 596                 //              iters-1, max_iters);
 597                 roam_sphere_merge_one(self);
 598                 roam_sphere_split_one(self);
 599         }
 600
 601         return iters;
 602 }
 603 void roam_sphere_draw(RoamSphere *self)
 604 {
 605         g_debug("RoamSphere: draw");
 606         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw, NULL);
 607 }
 608 void roam_sphere_draw_normals(RoamSphere *self)
 609 {
 610         g_debug("RoamSphere: draw_normal");
 611         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 612 }
 613 GList *_roam_sphere_get_leaves(RoamTriangle *tri, GList *list)
 614 {
 615         if (tri->kids[0] && tri->kids[1]) {
 616                 list = _roam_sphere_get_leaves(tri->kids[0], list);
 617                 list = _roam_sphere_get_leaves(tri->kids[1], list);
 618                 return list;
 619         } else {
 620                 return g_list_append(list, tri);
 621         }
 622 }
 623 GList *_roam_sphere_get_intersect_rec(RoamTriangle *tri, GList *list,
 624                 gdouble n, gdouble s, gdouble e, gdouble w)
 625 {
 626         gdouble tn = tri->edge.n;
 627         gdouble ts = tri->edge.s;
 628         gdouble te = tri->edge.e;
 629         gdouble tw = tri->edge.w;
 630
 631         gboolean debug = FALSE  &&
 632                 n==90 && s==45 && e==-90 && w==-180 &&
 633                 ts > 44 && ts < 46;
 634
 635         if (debug)
 636                 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
 637                             tri, tn,   s,   ts,   n,   te,   w,   tw,   e);
 638         if (tn < s || ts > n || te < w || tw > e) {
 639                 /* No intersect */
 640                 if (debug) g_message("no intersect");
 641                 return list;
 642         } else if (tn < n && ts > s && te < e && tw > w) {
 643                 /* Triangle is completely contained */
 644                 if (debug) g_message("contained");
 645                 return _roam_sphere_get_leaves(tri, list);
 646         } else if (tri->kids[0] && tri->kids[1]) {
 647                 /* Paritial intersect with children */
 648                 if (debug) g_message("edge w/ child");
 649                 list = _roam_sphere_get_intersect_rec(tri->kids[0], list, n, s, e, w);
 650                 list = _roam_sphere_get_intersect_rec(tri->kids[1], list, n, s, e, w);
 651                 return list;
 652         } else {
 653                 /* This triangle is an edge case */
 654                 if (debug) g_message("edge");
 655                 return g_list_append(list, tri);
 656         }
 657 }
 658 GList *roam_sphere_get_intersect(RoamSphere *self,
 659                 gdouble n, gdouble s, gdouble e, gdouble w)
 660 {
 661         /* I think this is correct..
 662          * i_cost = cost for triangle-rectagnle intersect test
 663          * time = n_tiles * 2*tris_per_tile * i_cost
 664          * time = 30      * 2*333           * i_cost = 20000 * i_cost */
 665         GList *list = NULL;
 666         for (int i = 0; i < G_N_ELEMENTS(self->roots); i++)
 667                 list = _roam_sphere_get_intersect_rec(self->roots[i],
 668                                 list, n, s, e, w);
 669         return list;
 670 }
 671 void roam_sphere_free_tri(RoamTriangle *tri)
 672 {
 673         if (--tri->p.l->tris == 0) g_free(tri->p.l);
 674         if (--tri->p.m->tris == 0) g_free(tri->p.m);
 675         if (--tri->p.r->tris == 0) g_free(tri->p.r);
 676         roam_triangle_free(tri);
 677 }
 678 void roam_sphere_free(RoamSphere *self)
 679 {
 680         /* Slow method, but it should work */
 681         while (self->polys > 8)
 682                 roam_sphere_merge_one(self);
 683         /* TODO: free points */
 684         g_pqueue_foreach(self->triangles, (GFunc)roam_sphere_free_tri, NULL);
 685         g_pqueue_free(self->triangles);
 686         g_pqueue_free(self->diamonds);
 687         g_free(self->view);
 688         g_free(self);
 689 }