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 <GL/gl.h>
  22 #include <GL/glu.h>
  23
  24 #include "gpqueue.h"
  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 *point = g_new0(RoamPoint, 1);
  56         point->lat  = lat;
  57         point->lon  = lon;
  58         point->elev = elev;
  59         /* For get_intersect */
  60         lle2xyz(lat, lon, elev, &point->x, &point->y, &point->z);
  61         return point;
  62 }
  63
  64 static RoamPoint *roam_point_dup(RoamPoint *point)
  65 {
  66         RoamPoint *new = g_memdup(point, sizeof(RoamPoint));
  67         new->tris = 0;
  68         return new;
  69 }
  70 void roam_point_add_triangle(RoamPoint *point, RoamTriangle *triangle)
  71 {
  72         for (int i = 0; i < 3; i++) {
  73                 point->norm[i] *= point->tris;
  74                 point->norm[i] += triangle->norm[i];
  75         }
  76         point->tris++;
  77         for (int i = 0; i < 3; i++)
  78                 point->norm[i] /= point->tris;
  79 }
  80 void roam_point_remove_triangle(RoamPoint *point, RoamTriangle *triangle)
  81 {
  82         for (int i = 0; i < 3; i++) {
  83                 point->norm[i] *= point->tris;
  84                 point->norm[i] -= triangle->norm[i];
  85         }
  86         point->tris--;
  87         if (point->tris)
  88                 for (int i = 0; i < 3; i++)
  89                         point->norm[i] /= point->tris;
  90 }
  91 void roam_point_update_height(RoamPoint *point)
  92 {
  93         if (point->height_func) {
  94                 gdouble elev = point->height_func(
  95                                 point->lat, point->lon, point->height_data);
  96                 lle2xyz(point->lat, point->lon, elev,
  97                                 &point->x, &point->y, &point->z);
  98         }
  99 }
 100
 101 void roam_point_update_projection(RoamPoint *point, RoamView *view)
 102 {
 103         static int count   = 0;
 104         static int version = 0;
 105         if (version != view->version) {
 106                 g_debug("RoamPoint: Projected %d points", count);
 107                 count   = 0;
 108                 version = view->version;
 109         }
 110
 111         if (point->pversion != view->version) {
 112                 /* Cache projection */
 113                 gluProject(point->x, point->y, point->z,
 114                         view->model, view->proj, view->view,
 115                         &point->px, &point->py, &point->pz);
 116                 point->pversion = view->version;
 117                 count++;
 118         }
 119 }
 120
 121 /****************
 122  * RoamTriangle *
 123  ****************/
 124 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
 125 {
 126         RoamTriangle *triangle = g_new0(RoamTriangle, 1);
 127
 128         triangle->error = 0;
 129         triangle->p.l = l;
 130         triangle->p.m = m;
 131         triangle->p.r = r;
 132         triangle->split = roam_point_new(
 133                 (l->lat + r->lat)/2,
 134                 (ABS(l->lat) == 90 ? r->lon :
 135                  ABS(r->lat) == 90 ? l->lon :
 136                  lon_avg(l->lon, r->lon)),
 137                 (l->elev + r->elev)/2);
 138         /* TODO: Move this back to sphere, or actually use the nesting */
 139         triangle->split->height_func = m->height_func;
 140         triangle->split->height_data = m->height_data;
 141         roam_point_update_height(triangle->split);
 142         //if ((float)triangle->split->lat > 44 && (float)triangle->split->lat < 46)
 143         //      g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
 144         //                      l->lat, m->lat, r->lat, triangle->split->lat);
 145         //if ((float)l->lat == (float)r->lat &&
 146         //    (float)triangle->split->lat != (float)l->lat)
 147         //      g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
 148         //              triangle->split->lat, l->lat);
 149
 150         /* Update normal */
 151         double pa[3];
 152         double pb[3];
 153         pa[0] = triangle->p.l->x - triangle->p.m->x;
 154         pa[1] = triangle->p.l->y - triangle->p.m->y;
 155         pa[2] = triangle->p.l->z - triangle->p.m->z;
 156
 157         pb[0] = triangle->p.r->x - triangle->p.m->x;
 158         pb[1] = triangle->p.r->y - triangle->p.m->y;
 159         pb[2] = triangle->p.r->z - triangle->p.m->z;
 160
 161         triangle->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 162         triangle->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 163         triangle->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 164
 165         double total = sqrt(triangle->norm[0] * triangle->norm[0] +
 166                             triangle->norm[1] * triangle->norm[1] +
 167                             triangle->norm[2] * triangle->norm[2]);
 168
 169         triangle->norm[0] /= total;
 170         triangle->norm[1] /= total;
 171         triangle->norm[2] /= total;
 172
 173         /* Store bounding box, for get_intersect */
 174         RoamPoint *p[] = {l,m,r};
 175         triangle->edge.n =  -90; triangle->edge.s =  90;
 176         triangle->edge.e = -180; triangle->edge.w = 180;
 177         gboolean maxed = FALSE;
 178         for (int i = 0; i < G_N_ELEMENTS(p); i++) {
 179                 triangle->edge.n = MAX(triangle->edge.n, p[i]->lat);
 180                 triangle->edge.s = MIN(triangle->edge.s, p[i]->lat);
 181                 if (p[i]->lat == 90 || p[i]->lat == -90)
 182                         continue;
 183                 if (p[i]->lon == 180) {
 184                         maxed = TRUE;
 185                         continue;
 186                 }
 187                 triangle->edge.e = MAX(triangle->edge.e, p[i]->lon);
 188                 triangle->edge.w = MIN(triangle->edge.w, p[i]->lon);
 189         }
 190         if (maxed) {
 191                 if (triangle->edge.e < 0)
 192                         triangle->edge.w = -180;
 193                 else
 194                         triangle->edge.e =  180;
 195         }
 196
 197         //g_message("roam_triangle_new: %p", triangle);
 198         return triangle;
 199 }
 200
 201 void roam_triangle_free(RoamTriangle *triangle)
 202 {
 203         g_free(triangle->split);
 204         g_free(triangle);
 205 }
 206
 207 void roam_triangle_add(RoamTriangle *triangle,
 208                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 209                 RoamSphere *sphere)
 210 {
 211         triangle->t.l = left;
 212         triangle->t.b = base;
 213         triangle->t.r = right;
 214
 215         roam_point_add_triangle(triangle->p.l, triangle);
 216         roam_point_add_triangle(triangle->p.m, triangle);
 217         roam_point_add_triangle(triangle->p.r, triangle);
 218
 219         if (sphere->view)
 220                 roam_triangle_update_errors(triangle, sphere);
 221
 222         triangle->handle = g_pqueue_push(sphere->triangles, triangle);
 223 }
 224
 225 void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
 226 {
 227         /* Update vertex normals */
 228         roam_point_remove_triangle(triangle->p.l, triangle);
 229         roam_point_remove_triangle(triangle->p.m, triangle);
 230         roam_point_remove_triangle(triangle->p.r, triangle);
 231
 232         g_pqueue_remove(sphere->triangles, triangle->handle);
 233 }
 234
 235 static void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
 236 {
 237         if      (neigh->t.l == old) neigh->t.l = new;
 238         else if (neigh->t.b == old) neigh->t.b = new;
 239         else if (neigh->t.r == old) neigh->t.r = new;
 240         else g_assert_not_reached();
 241 }
 242
 243 static gboolean roam_point_visible(RoamPoint *triangle, RoamSphere *sphere)
 244 {
 245         gint *view = sphere->view->view;
 246         return triangle->px > view[0] && triangle->px < view[2] &&
 247                triangle->py > view[1] && triangle->py < view[3] &&
 248                triangle->pz > 0       && triangle->pz < 1;
 249 }
 250 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
 251 {
 252         /* Do this with a bounding box */
 253         return roam_point_visible(triangle->p.l, sphere) ||
 254                roam_point_visible(triangle->p.m, sphere) ||
 255                roam_point_visible(triangle->p.r, sphere);
 256 }
 257
 258 void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
 259 {
 260         /* Update points */
 261         roam_point_update_projection(triangle->p.l, sphere->view);
 262         roam_point_update_projection(triangle->p.m, sphere->view);
 263         roam_point_update_projection(triangle->p.r, sphere->view);
 264
 265         /* Not exactly correct, could be out on both sides (middle in) */
 266         if (!roam_triangle_visible(triangle, sphere)) {
 267                 triangle->error = -1;
 268         } else {
 269                 roam_point_update_projection(triangle->split, sphere->view);
 270                 RoamPoint *l = triangle->p.l;
 271                 RoamPoint *m = triangle->p.m;
 272                 RoamPoint *r = triangle->p.r;
 273                 RoamPoint *split = triangle->split;
 274
 275                 /*               l-r midpoint        projected l-r midpoint */
 276                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 277                 gdouble pydist = (l->py + r->py)/2 - split->py;
 278
 279                 triangle->error = sqrt(pxdist*pxdist + pydist*pydist);
 280
 281                 /* Multiply by size of triangle */
 282                 double size = -( l->px * (m->py - r->py) +
 283                                  m->px * (r->py - l->py) +
 284                                  r->px * (l->py - m->py) ) / 2.0;
 285
 286                 /* Size < 0 == backface */
 287                 //if (size < 0)
 288                 //      triangle->error *= -1;
 289                 triangle->error *= size;
 290         }
 291 }
 292
 293 void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
 294 {
 295         //g_message("roam_triangle_split: %p, e=%f\n", triangle, triangle->error);
 296
 297         sphere->polys += 2;
 298
 299         if (triangle != triangle->t.b->t.b)
 300                 roam_triangle_split(triangle->t.b, sphere);
 301         if (triangle != triangle->t.b->t.b)
 302                 g_assert_not_reached();
 303
 304         RoamTriangle *base = triangle->t.b;
 305
 306         /* Add new triangles */
 307         RoamPoint *mid = triangle->split;
 308         RoamTriangle *sl = triangle->kids[0] = roam_triangle_new(triangle->p.m, mid, triangle->p.l); // triangle Left
 309         RoamTriangle *sr = triangle->kids[1] = roam_triangle_new(triangle->p.r, mid, triangle->p.m); // triangle Right
 310         RoamTriangle *bl = base->kids[0] = roam_triangle_new(base->p.m, mid, base->p.l); // Base Left
 311         RoamTriangle *br = base->kids[1] = roam_triangle_new(base->p.r, mid, base->p.m); // Base Right
 312
 313         /*                triangle,l,  base,      r,  sphere */
 314         roam_triangle_add(sl, sr, triangle->t.l, br, sphere);
 315         roam_triangle_add(sr, bl, triangle->t.r, sl, sphere);
 316         roam_triangle_add(bl, br, base->t.l, sr, sphere);
 317         roam_triangle_add(br, sl, base->t.r, bl, sphere);
 318
 319         roam_triangle_sync_neighbors(sl, triangle, triangle->t.l);
 320         roam_triangle_sync_neighbors(sr, triangle, triangle->t.r);
 321         roam_triangle_sync_neighbors(bl, base, base->t.l);
 322         roam_triangle_sync_neighbors(br, base, base->t.r);
 323
 324         /* Remove old triangles */
 325         roam_triangle_remove(triangle, sphere);
 326         roam_triangle_remove(base, sphere);
 327
 328         /* Add/Remove diamonds */
 329         RoamDiamond *diamond = roam_diamond_new(triangle, base, sl, sr, bl, br);
 330         roam_diamond_update_errors(diamond, sphere);
 331         roam_diamond_add(diamond, sphere);
 332         roam_diamond_remove(triangle->parent, sphere);
 333         roam_diamond_remove(base->parent, sphere);
 334 }
 335
 336 void roam_triangle_draw(RoamTriangle *triangle)
 337 {
 338         glBegin(GL_TRIANGLES);
 339         glNormal3dv(triangle->p.r->norm); glVertex3dv((double*)triangle->p.r);
 340         glNormal3dv(triangle->p.m->norm); glVertex3dv((double*)triangle->p.m);
 341         glNormal3dv(triangle->p.l->norm); glVertex3dv((double*)triangle->p.l);
 342         glEnd();
 343         return;
 344 }
 345
 346 void roam_triangle_draw_normal(RoamTriangle *triangle)
 347 {
 348         double center[] = {
 349                 (triangle->p.l->x + triangle->p.m->x + triangle->p.r->x)/3.0,
 350                 (triangle->p.l->y + triangle->p.m->y + triangle->p.r->y)/3.0,
 351                 (triangle->p.l->z + triangle->p.m->z + triangle->p.r->z)/3.0,
 352         };
 353         double end[] = {
 354                 center[0]+triangle->norm[0]*2000000,
 355                 center[1]+triangle->norm[1]*2000000,
 356                 center[2]+triangle->norm[2]*2000000,
 357         };
 358         glBegin(GL_LINES);
 359         glVertex3dv(center);
 360         glVertex3dv(end);
 361         glEnd();
 362 }
 363
 364 /***************
 365  * RoamDiamond *
 366  ***************/
 367 RoamDiamond *roam_diamond_new(
 368                 RoamTriangle *parent0, RoamTriangle *parent1,
 369                 RoamTriangle *kid0, RoamTriangle *kid1,
 370                 RoamTriangle *kid2, RoamTriangle *kid3)
 371 {
 372         RoamDiamond *diamond = g_new0(RoamDiamond, 1);
 373
 374         diamond->kids[0] = kid0;
 375         diamond->kids[1] = kid1;
 376         diamond->kids[2] = kid2;
 377         diamond->kids[3] = kid3;
 378
 379         kid0->parent = diamond;
 380         kid1->parent = diamond;
 381         kid2->parent = diamond;
 382         kid3->parent = diamond;
 383
 384         diamond->parents[0] = parent0;
 385         diamond->parents[1] = parent1;
 386
 387         return diamond;
 388 }
 389 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere)
 390 {
 391         diamond->active = TRUE;
 392         diamond->error  = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
 393         diamond->handle = g_pqueue_push(sphere->diamonds, diamond);
 394 }
 395 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere)
 396 {
 397         if (diamond && diamond->active) {
 398                 diamond->active = FALSE;
 399                 g_pqueue_remove(sphere->diamonds, diamond->handle);
 400         }
 401 }
 402 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
 403 {
 404         //g_message("roam_diamond_merge: %p, e=%f\n", diamond, diamond->error);
 405
 406         sphere->polys -= 2;
 407
 408         /* TODO: pick the best split */
 409         RoamTriangle **kids = diamond->kids;
 410
 411         /* Create triangles */
 412         RoamTriangle *triangle  = diamond->parents[0];
 413         RoamTriangle *base = diamond->parents[1];
 414
 415         roam_triangle_add(triangle,  kids[0]->t.b, base, kids[1]->t.b, sphere);
 416         roam_triangle_add(base, kids[2]->t.b, triangle,  kids[3]->t.b, sphere);
 417
 418         roam_triangle_sync_neighbors(triangle,  kids[0], kids[0]->t.b);
 419         roam_triangle_sync_neighbors(triangle,  kids[1], kids[1]->t.b);
 420         roam_triangle_sync_neighbors(base, kids[2], kids[2]->t.b);
 421         roam_triangle_sync_neighbors(base, kids[3], kids[3]->t.b);
 422
 423         /* Remove triangles */
 424         roam_triangle_remove(kids[0], sphere);
 425         roam_triangle_remove(kids[1], sphere);
 426         roam_triangle_remove(kids[2], sphere);
 427         roam_triangle_remove(kids[3], sphere);
 428
 429         /* Clear kids */
 430         triangle->kids[0]  = triangle->kids[1]  = NULL;
 431         base->kids[0] = base->kids[1] = NULL;
 432
 433         /* Add/Remove triangles */
 434         if (triangle->t.l->t.l == triangle->t.r->t.r &&
 435             triangle->t.l->t.l != triangle && triangle->parent) {
 436                 roam_diamond_update_errors(triangle->parent, sphere);
 437                 roam_diamond_add(triangle->parent, sphere);
 438         }
 439
 440         if (base->t.l->t.l == base->t.r->t.r &&
 441             base->t.l->t.l != base && base->parent) {
 442                 roam_diamond_update_errors(base->parent, sphere);
 443                 roam_diamond_add(base->parent, sphere);
 444         }
 445
 446         /* Remove and free diamond and child triangles */
 447         roam_diamond_remove(diamond, sphere);
 448         g_assert(diamond->kids[0]->p.m == diamond->kids[1]->p.m &&
 449                  diamond->kids[1]->p.m == diamond->kids[2]->p.m &&
 450                  diamond->kids[2]->p.m == diamond->kids[3]->p.m);
 451         g_assert(diamond->kids[0]->p.m->tris == 0);
 452         roam_triangle_free(diamond->kids[0]);
 453         roam_triangle_free(diamond->kids[1]);
 454         roam_triangle_free(diamond->kids[2]);
 455         roam_triangle_free(diamond->kids[3]);
 456         g_free(diamond);
 457 }
 458 void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere)
 459 {
 460         roam_triangle_update_errors(diamond->parents[0], sphere);
 461         roam_triangle_update_errors(diamond->parents[1], sphere);
 462         diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
 463 }
 464
 465 /**************
 466  * RoamSphere *
 467  **************/
 468 RoamSphere *roam_sphere_new()
 469 {
 470         RoamSphere *sphere = g_new0(RoamSphere, 1);
 471         sphere->polys       = 8;
 472         sphere->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 473         sphere->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 474
 475         RoamPoint *vertexes[] = {
 476                 roam_point_new( 90,   0,  0), // 0 (North)
 477                 roam_point_new(-90,   0,  0), // 1 (South)
 478                 roam_point_new(  0,   0,  0), // 2 (Europe/Africa)
 479                 roam_point_new(  0,  90,  0), // 3 (Asia,East)
 480                 roam_point_new(  0, 180,  0), // 4 (Pacific)
 481                 roam_point_new(  0, -90,  0), // 5 (Americas,West)
 482         };
 483         int _triangles[][2][3] = {
 484                 /*lv mv rv   ln, bn, rn */
 485                 {{2,0,3}, {3, 4, 1}}, // 0
 486                 {{3,0,4}, {0, 5, 2}}, // 1
 487                 {{4,0,5}, {1, 6, 3}}, // 2
 488                 {{5,0,2}, {2, 7, 0}}, // 3
 489                 {{3,1,2}, {5, 0, 7}}, // 4
 490                 {{4,1,3}, {6, 1, 4}}, // 5
 491                 {{5,1,4}, {7, 2, 5}}, // 6
 492                 {{2,1,5}, {4, 3, 6}}, // 7
 493         };
 494
 495         for (int i = 0; i < 6; i++)
 496                 roam_point_update_height(vertexes[i]);
 497         for (int i = 0; i < 8; i++)
 498                 sphere->roots[i] = roam_triangle_new(
 499                         vertexes[_triangles[i][0][0]],
 500                         vertexes[_triangles[i][0][1]],
 501                         vertexes[_triangles[i][0][2]]);
 502         for (int i = 0; i < 8; i++)
 503                 roam_triangle_add(sphere->roots[i],
 504                         sphere->roots[_triangles[i][1][0]],
 505                         sphere->roots[_triangles[i][1][1]],
 506                         sphere->roots[_triangles[i][1][2]],
 507                         sphere);
 508         for (int i = 0; i < 8; i++)
 509                 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", sphere->roots[i],
 510                                 sphere->roots[i]->edge.n,
 511                                 sphere->roots[i]->edge.s,
 512                                 sphere->roots[i]->edge.e,
 513                                 sphere->roots[i]->edge.w);
 514
 515         return sphere;
 516 }
 517 void roam_sphere_update_view(RoamSphere *sphere)
 518 {
 519         if (!sphere->view)
 520                 sphere->view = g_new0(RoamView, 1);
 521         glGetDoublev (GL_MODELVIEW_MATRIX,  sphere->view->model);
 522         glGetDoublev (GL_PROJECTION_MATRIX, sphere->view->proj);
 523         glGetIntegerv(GL_VIEWPORT,          sphere->view->view);
 524         sphere->view->version++;
 525 }
 526 void roam_sphere_update_errors(RoamSphere *sphere)
 527 {
 528         g_debug("RoamSphere: update_errors - polys=%d", sphere->polys);
 529         GPtrArray *tris = g_pqueue_get_array(sphere->triangles);
 530         GPtrArray *dias = g_pqueue_get_array(sphere->diamonds);
 531
 532         roam_sphere_update_view(sphere);
 533
 534         for (int i = 0; i < tris->len; i++) {
 535                 RoamTriangle *triangle = tris->pdata[i];
 536                 roam_triangle_update_errors(triangle, sphere);
 537                 g_pqueue_priority_changed(sphere->triangles, triangle->handle);
 538         }
 539
 540         for (int i = 0; i < dias->len; i++) {
 541                 RoamDiamond *diamond = dias->pdata[i];
 542                 roam_diamond_update_errors(diamond, sphere);
 543                 g_pqueue_priority_changed(sphere->diamonds, diamond->handle);
 544         }
 545
 546         g_ptr_array_free(tris, TRUE);
 547         g_ptr_array_free(dias, TRUE);
 548 }
 549
 550 void roam_sphere_split_one(RoamSphere *sphere)
 551 {
 552         RoamTriangle *to_split = g_pqueue_peek(sphere->triangles);
 553         if (!to_split) return;
 554         roam_triangle_split(to_split, sphere);
 555 }
 556 void roam_sphere_merge_one(RoamSphere *sphere)
 557 {
 558         RoamDiamond *to_merge = g_pqueue_peek(sphere->diamonds);
 559         if (!to_merge) return;
 560         roam_diamond_merge(to_merge, sphere);
 561 }
 562 gint roam_sphere_split_merge(RoamSphere *sphere)
 563 {
 564         gint iters = 0, max_iters = 500;
 565         //gint target = 4000;
 566         gint target = 2000;
 567         //gint target = 500;
 568
 569         if (!sphere->view)
 570                 return 0;
 571
 572         if (target - sphere->polys > 100) {
 573                 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, sphere->polys);
 574                 while (sphere->polys < target && iters++ < max_iters)
 575                         roam_sphere_split_one(sphere);
 576         }
 577
 578         if (sphere->polys - target > 100) {
 579                 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", sphere->polys, target);
 580                 while (sphere->polys > target && iters++ < max_iters)
 581                         roam_sphere_merge_one(sphere);
 582         }
 583
 584         while (((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error >
 585                ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error &&
 586                iters++ < max_iters) {
 587                 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
 588                 //              ((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error,
 589                 //              ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error,
 590                 //              iters-1, max_iters);
 591                 roam_sphere_merge_one(sphere);
 592                 roam_sphere_split_one(sphere);
 593         }
 594
 595         return iters;
 596 }
 597 void roam_sphere_draw(RoamSphere *sphere)
 598 {
 599         g_debug("RoamSphere: draw");
 600         g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw, NULL);
 601 }
 602 void roam_sphere_draw_normals(RoamSphere *sphere)
 603 {
 604         g_debug("RoamSphere: draw_normal");
 605         g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 606 }
 607 static GList *_roam_sphere_get_leaves(RoamTriangle *triangle, GList *list, gboolean all)
 608 {
 609         if (triangle->kids[0] && triangle->kids[1]) {
 610                 if (all) list = g_list_prepend(list, triangle);
 611                 list = _roam_sphere_get_leaves(triangle->kids[0], list, all);
 612                 list = _roam_sphere_get_leaves(triangle->kids[1], list, all);
 613                 return list;
 614         } else {
 615                 return g_list_prepend(list, triangle);
 616         }
 617 }
 618 static GList *_roam_sphere_get_intersect_rec(RoamTriangle *triangle, GList *list,
 619                 gboolean all, gdouble n, gdouble s, gdouble e, gdouble w)
 620 {
 621         gdouble tn = triangle->edge.n;
 622         gdouble ts = triangle->edge.s;
 623         gdouble te = triangle->edge.e;
 624         gdouble tw = triangle->edge.w;
 625
 626         gboolean debug = FALSE  &&
 627                 n==90 && s==45 && e==-90 && w==-180 &&
 628                 ts > 44 && ts < 46;
 629
 630         if (debug)
 631                 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
 632                             triangle, tn,   s,   ts,   n,   te,   w,   tw,   e);
 633         if (tn < s || ts > n || te < w || tw > e) {
 634                 /* No intersect */
 635                 if (debug) g_message("no intersect");
 636                 return list;
 637         } else if (tn <= n && ts >= s && te <= e && tw >= w) {
 638                 /* Triangle is completely contained */
 639                 if (debug) g_message("contained");
 640                 if (all) list = g_list_prepend(list, triangle);
 641                 return _roam_sphere_get_leaves(triangle, list, all);
 642         } else if (triangle->kids[0] && triangle->kids[1]) {
 643                 /* Paritial intersect with children */
 644                 if (debug) g_message("edge w/ child");
 645                 if (all) list = g_list_prepend(list, triangle);
 646                 list = _roam_sphere_get_intersect_rec(triangle->kids[0], list, all, n, s, e, w);
 647                 list = _roam_sphere_get_intersect_rec(triangle->kids[1], list, all, n, s, e, w);
 648                 return list;
 649         } else {
 650                 /* This triangle is an edge case */
 651                 if (debug) g_message("edge");
 652                 return g_list_prepend(list, triangle);
 653         }
 654 }
 655 /* Warning: This grabs pointers to triangles which can be changed by other
 656  * calls, e.g. split_merge. If you use this, you need to do some locking to
 657  * prevent the returned list from becomming stale. */
 658 GList *roam_sphere_get_intersect(RoamSphere *sphere, gboolean all,
 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(sphere->roots); i++)
 667                 list = _roam_sphere_get_intersect_rec(sphere->roots[i],
 668                                 list, all, n, s, e, w);
 669         return list;
 670 }
 671
 672 static void roam_sphere_free_tri(RoamTriangle *triangle)
 673 {
 674         if (--triangle->p.l->tris == 0) g_free(triangle->p.l);
 675         if (--triangle->p.m->tris == 0) g_free(triangle->p.m);
 676         if (--triangle->p.r->tris == 0) g_free(triangle->p.r);
 677         roam_triangle_free(triangle);
 678 }
 679 void roam_sphere_free(RoamSphere *sphere)
 680 {
 681         g_debug("RoamSphere: free");
 682         /* Slow method, but it should work */
 683         while (sphere->polys > 8)
 684                 roam_sphere_merge_one(sphere);
 685         /* TODO: free points */
 686         g_pqueue_foreach(sphere->triangles, (GFunc)roam_sphere_free_tri, NULL);
 687         g_pqueue_free(sphere->triangles);
 688         g_pqueue_free(sphere->diamonds);
 689         g_free(sphere->view);
 690         g_free(sphere);
 691 }