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 /**
  19  * SECTION:roam
  20  * @short_description: Realtime Optimally-Adapting Meshes
  21  *
  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.
  26  *
  27  * This implementation of the ROAM algorithm is based on an octahedron as the
  28  * base model.
  29  */
  30
  31 #include <glib.h>
  32 #include <math.h>
  33 #include <string.h>
  34 #include <GL/gl.h>
  35 #include <GL/glu.h>
  36
  37 #include "gpqueue.h"
  38 #include "gis-util.h"
  39 #include "roam.h"
  40
  41 /*
  42  * TODO:
  43  *   - Optimize for memory consumption
  44  *   - Profile for computation speed
  45  *   - Target polygon count/detail
  46  */
  47
  48 /* For GPQueue comparators */
  49 static gint tri_cmp(RoamTriangle *a, RoamTriangle *b, gpointer data)
  50 {
  51         if      (a->error < b->error) return  1;
  52         else if (a->error > b->error) return -1;
  53         else                          return  0;
  54 }
  55 static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data)
  56 {
  57         if      (a->error < b->error) return -1;
  58         else if (a->error > b->error) return  1;
  59         else                          return  0;
  60 }
  61
  62
  63 /*************
  64  * RoamPoint *
  65  *************/
  66 /**
  67  * roam_point_new:
  68  * @lat:  the latitude for the point
  69  * @lon:  the longitude for the point
  70  * @elev: the elevation for the point
  71  *
  72  * Create a new point at the given locaiton
  73  *
  74  * Returns: the new point
  75  */
  76 RoamPoint *roam_point_new(gdouble lat, gdouble lon, gdouble elev)
  77 {
  78         RoamPoint *point = g_new0(RoamPoint, 1);
  79         point->lat  = lat;
  80         point->lon  = lon;
  81         point->elev = elev;
  82         /* For get_intersect */
  83         lle2xyz(lat, lon, elev, &point->x, &point->y, &point->z);
  84         return point;
  85 }
  86
  87 /**
  88  * roam_point_add_triangle:
  89  * @point:    the point
  90  * @triangle: the to add
  91  *
  92  * Associating a triangle with a point and update it's vertex normal.
  93  */
  94 void roam_point_add_triangle(RoamPoint *point, RoamTriangle *triangle)
  95 {
  96         for (int i = 0; i < 3; i++) {
  97                 point->norm[i] *= point->tris;
  98                 point->norm[i] += triangle->norm[i];
  99         }
 100         point->tris++;
 101         for (int i = 0; i < 3; i++)
 102                 point->norm[i] /= point->tris;
 103 }
 104
 105 /**
 106  * roam_point_remove_triangle:
 107  * @point:    the point
 108  * @triangle: the to add
 109  *
 110  * Un-associating a triangle with a point and update it's vertex normal.
 111  */
 112 void roam_point_remove_triangle(RoamPoint *point, RoamTriangle *triangle)
 113 {
 114         for (int i = 0; i < 3; i++) {
 115                 point->norm[i] *= point->tris;
 116                 point->norm[i] -= triangle->norm[i];
 117         }
 118         point->tris--;
 119         if (point->tris)
 120                 for (int i = 0; i < 3; i++)
 121                         point->norm[i] /= point->tris;
 122 }
 123
 124 /**
 125  * roam_point_update_height:
 126  * @point: the point
 127  *
 128  * Update the height (elevation) of a point based on the current height function
 129  */
 130 void roam_point_update_height(RoamPoint *point)
 131 {
 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);
 137         }
 138 }
 139
 140 /**
 141  * roam_point_update_projection:
 142  * @point: the point
 143  * @view:  the view to use when projecting the point
 144  *
 145  * Updated the screen-space projection of a point.
 146  */
 147 void roam_point_update_projection(RoamPoint *point, RoamView *view)
 148 {
 149         static int count   = 0;
 150         static int version = 0;
 151         if (version != view->version) {
 152                 g_debug("RoamPoint: Projected %d points", count);
 153                 count   = 0;
 154                 version = view->version;
 155         }
 156
 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;
 163                 count++;
 164         }
 165 }
 166
 167 /****************
 168  * RoamTriangle *
 169  ****************/
 170 /**
 171  * roam_triangle_new:
 172  * @l: the left point
 173  * @m: the middle point
 174  * @r: the right point
 175  *
 176  * Create a new triangle consisting of three points.
 177  *
 178  * Returns: the new triangle
 179  */
 180 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
 181                 RoamDiamond *parent)
 182 {
 183         RoamTriangle *triangle = g_new0(RoamTriangle, 1);
 184
 185         triangle->error  = 0;
 186         triangle->p.l    = l;
 187         triangle->p.m    = m;
 188         triangle->p.r    = r;
 189         triangle->parent = parent;
 190         triangle->split  = roam_point_new(
 191                 (l->lat + r->lat)/2,
 192                 (ABS(l->lat) == 90 ? r->lon :
 193                  ABS(r->lat) == 90 ? l->lon :
 194                  lon_avg(l->lon, r->lon)),
 195                 (l->elev + r->elev)/2);
 196         /* TODO: Move this back to sphere, or actually use the nesting */
 197         triangle->split->height_func = m->height_func;
 198         triangle->split->height_data = m->height_data;
 199         roam_point_update_height(triangle->split);
 200         //if ((float)triangle->split->lat > 44 && (float)triangle->split->lat < 46)
 201         //      g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
 202         //                      l->lat, m->lat, r->lat, triangle->split->lat);
 203         //if ((float)l->lat == (float)r->lat &&
 204         //    (float)triangle->split->lat != (float)l->lat)
 205         //      g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
 206         //              triangle->split->lat, l->lat);
 207
 208         /* Update normal */
 209         double pa[3];
 210         double pb[3];
 211         pa[0] = triangle->p.l->x - triangle->p.m->x;
 212         pa[1] = triangle->p.l->y - triangle->p.m->y;
 213         pa[2] = triangle->p.l->z - triangle->p.m->z;
 214
 215         pb[0] = triangle->p.r->x - triangle->p.m->x;
 216         pb[1] = triangle->p.r->y - triangle->p.m->y;
 217         pb[2] = triangle->p.r->z - triangle->p.m->z;
 218
 219         triangle->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 220         triangle->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 221         triangle->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 222
 223         double total = sqrt(triangle->norm[0] * triangle->norm[0] +
 224                             triangle->norm[1] * triangle->norm[1] +
 225                             triangle->norm[2] * triangle->norm[2]);
 226
 227         triangle->norm[0] /= total;
 228         triangle->norm[1] /= total;
 229         triangle->norm[2] /= total;
 230
 231         /* Store bounding box, for get_intersect */
 232         RoamPoint *p[] = {l,m,r};
 233         triangle->edge.n =  -90; triangle->edge.s =  90;
 234         triangle->edge.e = -180; triangle->edge.w = 180;
 235         gboolean maxed = FALSE;
 236         for (int i = 0; i < G_N_ELEMENTS(p); i++) {
 237                 triangle->edge.n = MAX(triangle->edge.n, p[i]->lat);
 238                 triangle->edge.s = MIN(triangle->edge.s, p[i]->lat);
 239                 if (p[i]->lat == 90 || p[i]->lat == -90)
 240                         continue;
 241                 if (p[i]->lon == 180) {
 242                         maxed = TRUE;
 243                         continue;
 244                 }
 245                 triangle->edge.e = MAX(triangle->edge.e, p[i]->lon);
 246                 triangle->edge.w = MIN(triangle->edge.w, p[i]->lon);
 247         }
 248         if (maxed) {
 249                 if (triangle->edge.e < 0)
 250                         triangle->edge.w = -180;
 251                 else
 252                         triangle->edge.e =  180;
 253         }
 254
 255         //g_message("roam_triangle_new: %p", triangle);
 256         return triangle;
 257 }
 258
 259 /**
 260  * roam_triangle_free:
 261  * @triangle: the triangle
 262  *
 263  * Free data associated with a triangle
 264  */
 265 void roam_triangle_free(RoamTriangle *triangle)
 266 {
 267         g_free(triangle->split);
 268         g_free(triangle);
 269 }
 270
 271 /**
 272  * roam_triangle_add:
 273  * @triangle: the triangle
 274  * @left:     the left neighbor
 275  * @base:     the base neighbor
 276  * @right:    the right neighbor
 277  * @sphere:   the sphere to add the triangle to
 278  *
 279  * Add a triangle into the sphere's mesh using the given neighbors.
 280  */
 281 void roam_triangle_add(RoamTriangle *triangle,
 282                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 283                 RoamSphere *sphere)
 284 {
 285         triangle->t.l = left;
 286         triangle->t.b = base;
 287         triangle->t.r = right;
 288
 289         roam_point_add_triangle(triangle->p.l, triangle);
 290         roam_point_add_triangle(triangle->p.m, triangle);
 291         roam_point_add_triangle(triangle->p.r, triangle);
 292
 293         if (sphere->view)
 294                 roam_triangle_update_errors(triangle, sphere);
 295
 296         triangle->handle = g_pqueue_push(sphere->triangles, triangle);
 297 }
 298
 299 /**
 300  * roam_triangle_remove:
 301  * @triangle: the triangle
 302  * @sphere:   the sphere to remove the triangle from
 303  *
 304  * Remove a triangle from a sphere's mesh.
 305  */
 306 void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
 307 {
 308         /* Update vertex normals */
 309         roam_point_remove_triangle(triangle->p.l, triangle);
 310         roam_point_remove_triangle(triangle->p.m, triangle);
 311         roam_point_remove_triangle(triangle->p.r, triangle);
 312
 313         g_pqueue_remove(sphere->triangles, triangle->handle);
 314 }
 315
 316 /* (neight->t.? == old) = new */
 317 static void roam_triangle_sync_neighbors(RoamTriangle *neigh, RoamTriangle *old, RoamTriangle *new)
 318 {
 319         if      (neigh->t.l == old) neigh->t.l = new;
 320         else if (neigh->t.b == old) neigh->t.b = new;
 321         else if (neigh->t.r == old) neigh->t.r = new;
 322 }
 323
 324 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
 325 {
 326         RoamPoint *l = triangle->p.l;
 327         RoamPoint *m = triangle->p.m;
 328         RoamPoint *r = triangle->p.r;
 329         gdouble min_x = MIN(MIN(l->px, m->px), r->px);
 330         gdouble max_x = MAX(MAX(l->px, m->px), r->px);
 331         gdouble min_y = MIN(MIN(l->py, m->py), r->py);
 332         gdouble max_y = MAX(MAX(l->py, m->py), r->py);
 333         gint *view = sphere->view->view;
 334         return !(max_x < view[0] || min_x > view[2] ||
 335                  max_y < view[1] || min_y > view[3]) &&
 336                  l->pz > 0 && m->pz > 0 && r->pz > 0 &&
 337                  l->pz < 1 && m->pz < 1 && r->pz < 1;
 338 }
 339
 340 static gboolean roam_triangle_backface(RoamTriangle *triangle, RoamSphere *sphere)
 341 {
 342         RoamPoint *l = triangle->p.l;
 343         RoamPoint *m = triangle->p.m;
 344         RoamPoint *r = triangle->p.r;
 345         roam_point_update_projection(l, sphere->view);
 346         roam_point_update_projection(m, sphere->view);
 347         roam_point_update_projection(r, sphere->view);
 348         double size = -( l->px * (m->py - r->py) +
 349                          m->px * (r->py - l->py) +
 350                          r->px * (l->py - m->py) ) / 2.0;
 351         return size < 0;
 352 }
 353
 354 /**
 355  * roam_triangle_update_errors:
 356  * @triangle: the triangle
 357  * @sphere:   the sphere to use when updating errors
 358  *
 359  * Update the error value associated with a triangle. Called when the view
 360  * changes.
 361  */
 362 void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
 363 {
 364         /* Update points */
 365         roam_point_update_projection(triangle->p.l, sphere->view);
 366         roam_point_update_projection(triangle->p.m, sphere->view);
 367         roam_point_update_projection(triangle->p.r, sphere->view);
 368
 369         if (!roam_triangle_visible(triangle, sphere)) {
 370                 triangle->error = -1;
 371         } else {
 372                 roam_point_update_projection(triangle->split, sphere->view);
 373                 RoamPoint *l     = triangle->p.l;
 374                 RoamPoint *m     = triangle->p.m;
 375                 RoamPoint *r     = triangle->p.r;
 376                 RoamPoint *split = triangle->split;
 377
 378                 /*               l-r midpoint        projected l-r midpoint */
 379                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 380                 gdouble pydist = (l->py + r->py)/2 - split->py;
 381
 382                 triangle->error = sqrt(pxdist*pxdist + pydist*pydist);
 383
 384                 /* Multiply by size of triangle */
 385                 double size = -( l->px * (m->py - r->py) +
 386                                  m->px * (r->py - l->py) +
 387                                  r->px * (l->py - m->py) ) / 2.0;
 388
 389                 /* Size < 0 == backface */
 390                 triangle->error *= size;
 391
 392                 /* Give some preference to "edge" faces */
 393                 if (roam_triangle_backface(triangle->t.l, sphere) ||
 394                     roam_triangle_backface(triangle->t.b, sphere) ||
 395                     roam_triangle_backface(triangle->t.r, sphere))
 396                         triangle->error *= 500;
 397         }
 398 }
 399
 400 /**
 401  * roam_triangle_split:
 402  * @triangle: the triangle
 403  * @sphere:   the sphere
 404  *
 405  * Split a triangle into two child triangles and update the sphere.
 406  * triangle
 407  */
 408 void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
 409 {
 410         //g_message("roam_triangle_split: %p, e=%f\n", triangle, triangle->error);
 411
 412         sphere->polys += 2;
 413
 414         if (triangle != triangle->t.b->t.b)
 415                 roam_triangle_split(triangle->t.b, sphere);
 416         if (triangle != triangle->t.b->t.b)
 417                 g_assert_not_reached();
 418
 419         RoamTriangle *s = triangle;      // Self
 420         RoamTriangle *b = triangle->t.b; // Base
 421
 422         RoamDiamond *dia = roam_diamond_new(s, b);
 423
 424         /* Add new triangles */
 425         RoamPoint *mid = triangle->split;
 426         RoamTriangle *sl = s->kids[0] = roam_triangle_new(s->p.m, mid, s->p.l, dia); // Self Left
 427         RoamTriangle *sr = s->kids[1] = roam_triangle_new(s->p.r, mid, s->p.m, dia); // Self Right
 428         RoamTriangle *bl = b->kids[0] = roam_triangle_new(b->p.m, mid, b->p.l, dia); // Base Left
 429         RoamTriangle *br = b->kids[1] = roam_triangle_new(b->p.r, mid, b->p.m, dia); // Base Right
 430
 431         /*                triangle,l,  base,      r,  sphere */
 432         roam_triangle_add(sl, sr, s->t.l, br, sphere);
 433         roam_triangle_add(sr, bl, s->t.r, sl, sphere);
 434         roam_triangle_add(bl, br, b->t.l, sr, sphere);
 435         roam_triangle_add(br, sl, b->t.r, bl, sphere);
 436
 437         roam_triangle_sync_neighbors(s->t.l, s, sl);
 438         roam_triangle_sync_neighbors(s->t.r, s, sr);
 439         roam_triangle_sync_neighbors(b->t.l, b, bl);
 440         roam_triangle_sync_neighbors(b->t.r, b, br);
 441
 442         /* Remove old triangles */
 443         roam_triangle_remove(s, sphere);
 444         roam_triangle_remove(b, sphere);
 445
 446         /* Add/Remove diamonds */
 447         roam_diamond_update_errors(dia, sphere);
 448         roam_diamond_add(dia, sphere);
 449         roam_diamond_remove(s->parent, sphere);
 450         roam_diamond_remove(b->parent, sphere);
 451 }
 452
 453 /**
 454  * roam_triangle_draw:
 455  * @triangle: the triangle
 456  *
 457  * Draw the triangle. Use for debugging.
 458  */
 459 void roam_triangle_draw(RoamTriangle *triangle)
 460 {
 461         glBegin(GL_TRIANGLES);
 462         glNormal3dv(triangle->p.r->norm); glVertex3dv((double*)triangle->p.r);
 463         glNormal3dv(triangle->p.m->norm); glVertex3dv((double*)triangle->p.m);
 464         glNormal3dv(triangle->p.l->norm); glVertex3dv((double*)triangle->p.l);
 465         glEnd();
 466         return;
 467 }
 468
 469 /**
 470  * roam_triangle_draw_normal:
 471  * @triangle: the triangle
 472  *
 473  * Draw a normal vector for the triangle. Used while debugging.
 474  */
 475 void roam_triangle_draw_normal(RoamTriangle *triangle)
 476 {
 477         double center[] = {
 478                 (triangle->p.l->x + triangle->p.m->x + triangle->p.r->x)/3.0,
 479                 (triangle->p.l->y + triangle->p.m->y + triangle->p.r->y)/3.0,
 480                 (triangle->p.l->z + triangle->p.m->z + triangle->p.r->z)/3.0,
 481         };
 482         double end[] = {
 483                 center[0]+triangle->norm[0]*2000000,
 484                 center[1]+triangle->norm[1]*2000000,
 485                 center[2]+triangle->norm[2]*2000000,
 486         };
 487         glBegin(GL_LINES);
 488         glVertex3dv(center);
 489         glVertex3dv(end);
 490         glEnd();
 491 }
 492
 493 /***************
 494  * RoamDiamond *
 495  ***************/
 496 /**
 497  * roam_diamond_new:
 498  * @parent0: a parent triangle
 499  * @parent1: a parent triangle
 500  * @kid0:    a child triangle
 501  * @kid1:    a child triangle
 502  * @kid2:    a child triangle
 503  * @kid3:    a child triangle
 504  *
 505  * Create a diamond to store information about two split triangles.
 506  *
 507  * Returns: the new diamond
 508  */
 509 RoamDiamond *roam_diamond_new(RoamTriangle *parent0, RoamTriangle *parent1)
 510 {
 511         RoamDiamond *diamond = g_new0(RoamDiamond, 1);
 512         diamond->parents[0] = parent0;
 513         diamond->parents[1] = parent1;
 514         return diamond;
 515 }
 516
 517 /**
 518  * roam_diamond_add:
 519  * @diamond: the diamond
 520  * @sphere:  the sphere to add the diamond to
 521  *
 522  * Add a diamond into the sphere's pool of diamonds. It will be check for
 523  * possible merges.
 524  */
 525 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere)
 526 {
 527         diamond->active = TRUE;
 528         diamond->error  = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
 529         diamond->handle = g_pqueue_push(sphere->diamonds, diamond);
 530 }
 531
 532 /**
 533  * roam_diamond_remove:
 534  * @diamond: the diamond
 535  * @sphere:  the sphere to remove the diamond from
 536  *
 537  * Remove a diamond from the sphere's pool of diamonds.
 538  */
 539 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere)
 540 {
 541         if (diamond && diamond->active) {
 542                 diamond->active = FALSE;
 543                 g_pqueue_remove(sphere->diamonds, diamond->handle);
 544         }
 545 }
 546
 547 /**
 548  * roam_diamond_merge:
 549  * @diamond: the diamond
 550  * @sphere:  the sphere
 551  *
 552  * "Merge" a diamond back into two parent triangles. The original two triangles
 553  * are added back into the sphere and the four child triangles as well as the
 554  * diamond are removed.
 555  */
 556 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
 557 {
 558         //g_message("roam_diamond_merge: %p, e=%f\n", diamond, diamond->error);
 559
 560         /* TODO: pick the best split */
 561         sphere->polys -= 2;
 562
 563         /* Use nicer temp names */
 564         RoamTriangle *s = diamond->parents[0]; // Self
 565         RoamTriangle *b = diamond->parents[1]; // Base
 566
 567         RoamTriangle *sl = s->kids[0];
 568         RoamTriangle *sr = s->kids[1];
 569         RoamTriangle *bl = b->kids[0];
 570         RoamTriangle *br = b->kids[1];
 571
 572         s->kids[0] = s->kids[1] = NULL;
 573         b->kids[0] = b->kids[1] = NULL;
 574
 575         /* Add original triangles */
 576         roam_triangle_sync_neighbors(s->t.l, sl, s);
 577         roam_triangle_sync_neighbors(s->t.r, sr, s);
 578         roam_triangle_sync_neighbors(b->t.l, bl, b);
 579         roam_triangle_sync_neighbors(b->t.r, br, b);
 580
 581         roam_triangle_add(s, sl->t.b, b, sr->t.b, sphere);
 582         roam_triangle_add(b, bl->t.b, s, br->t.b, sphere);
 583
 584         roam_triangle_sync_neighbors(sl->t.b, sl, s);
 585         roam_triangle_sync_neighbors(sr->t.b, sr, s);
 586         roam_triangle_sync_neighbors(bl->t.b, bl, b);
 587         roam_triangle_sync_neighbors(br->t.b, br, b);
 588
 589         /* Remove child triangles */
 590         roam_triangle_remove(sl, sphere);
 591         roam_triangle_remove(sr, sphere);
 592         roam_triangle_remove(bl, sphere);
 593         roam_triangle_remove(br, sphere);
 594
 595         /* Add/Remove triangles */
 596         if (s->t.l->t.l == s->t.r->t.r &&
 597             s->t.l->t.l != s && s->parent) {
 598                 roam_diamond_update_errors(s->parent, sphere);
 599                 roam_diamond_add(s->parent, sphere);
 600         }
 601
 602         if (b->t.l->t.l == b->t.r->t.r &&
 603             b->t.l->t.l != b && b->parent) {
 604                 roam_diamond_update_errors(b->parent, sphere);
 605                 roam_diamond_add(b->parent, sphere);
 606         }
 607
 608         /* Remove and free diamond and child triangles */
 609         roam_diamond_remove(diamond, sphere);
 610         g_assert(sl->p.m == sr->p.m &&
 611                  sr->p.m == bl->p.m &&
 612                  bl->p.m == br->p.m);
 613         g_assert(sl->p.m->tris == 0);
 614         roam_triangle_free(sl);
 615         roam_triangle_free(sr);
 616         roam_triangle_free(bl);
 617         roam_triangle_free(br);
 618         g_free(diamond);
 619 }
 620
 621 /**
 622  * roam_diamond_update_errors:
 623  * @diamond: the diamond
 624  * @sphere:  the sphere to use when updating errors
 625  *
 626  * Update the error value associated with a diamond. Called when the view
 627  * changes.
 628  */
 629 void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere)
 630 {
 631         roam_triangle_update_errors(diamond->parents[0], sphere);
 632         roam_triangle_update_errors(diamond->parents[1], sphere);
 633         diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
 634 }
 635
 636 /**************
 637  * RoamSphere *
 638  **************/
 639 /**
 640  * roam_sphere_new:
 641  *
 642  * Create a new sphere
 643  *
 644  * Returns: the sphere
 645  */
 646 RoamSphere *roam_sphere_new()
 647 {
 648         RoamSphere *sphere = g_new0(RoamSphere, 1);
 649         sphere->polys       = 8;
 650         sphere->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 651         sphere->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 652
 653         RoamPoint *vertexes[] = {
 654                 roam_point_new( 90,   0,  0), // 0 (North)
 655                 roam_point_new(-90,   0,  0), // 1 (South)
 656                 roam_point_new(  0,   0,  0), // 2 (Europe/Africa)
 657                 roam_point_new(  0,  90,  0), // 3 (Asia,East)
 658                 roam_point_new(  0, 180,  0), // 4 (Pacific)
 659                 roam_point_new(  0, -90,  0), // 5 (Americas,West)
 660         };
 661         int _triangles[][2][3] = {
 662                 /*lv mv rv   ln, bn, rn */
 663                 {{2,0,3}, {3, 4, 1}}, // 0
 664                 {{3,0,4}, {0, 5, 2}}, // 1
 665                 {{4,0,5}, {1, 6, 3}}, // 2
 666                 {{5,0,2}, {2, 7, 0}}, // 3
 667                 {{3,1,2}, {5, 0, 7}}, // 4
 668                 {{4,1,3}, {6, 1, 4}}, // 5
 669                 {{5,1,4}, {7, 2, 5}}, // 6
 670                 {{2,1,5}, {4, 3, 6}}, // 7
 671         };
 672
 673         for (int i = 0; i < 6; i++)
 674                 roam_point_update_height(vertexes[i]);
 675         for (int i = 0; i < 8; i++)
 676                 sphere->roots[i] = roam_triangle_new(
 677                         vertexes[_triangles[i][0][0]],
 678                         vertexes[_triangles[i][0][1]],
 679                         vertexes[_triangles[i][0][2]],
 680                         NULL);
 681         for (int i = 0; i < 8; i++)
 682                 roam_triangle_add(sphere->roots[i],
 683                         sphere->roots[_triangles[i][1][0]],
 684                         sphere->roots[_triangles[i][1][1]],
 685                         sphere->roots[_triangles[i][1][2]],
 686                         sphere);
 687         for (int i = 0; i < 8; i++)
 688                 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", sphere->roots[i],
 689                                 sphere->roots[i]->edge.n,
 690                                 sphere->roots[i]->edge.s,
 691                                 sphere->roots[i]->edge.e,
 692                                 sphere->roots[i]->edge.w);
 693
 694         return sphere;
 695 }
 696
 697 /**
 698  * roam_sphere_update_view
 699  * @sphere: the sphere
 700  *
 701  * Recreate the sphere's view matrices based on the current OpenGL state.
 702  */
 703 void roam_sphere_update_view(RoamSphere *sphere)
 704 {
 705         if (!sphere->view)
 706                 sphere->view = g_new0(RoamView, 1);
 707         glGetDoublev (GL_MODELVIEW_MATRIX,  sphere->view->model);
 708         glGetDoublev (GL_PROJECTION_MATRIX, sphere->view->proj);
 709         glGetIntegerv(GL_VIEWPORT,          sphere->view->view);
 710         sphere->view->version++;
 711 }
 712
 713 /**
 714  * roam_sphere_update_errors
 715  * @sphere: the sphere
 716  *
 717  * Update triangle and diamond errors in the sphere.
 718  */
 719 void roam_sphere_update_errors(RoamSphere *sphere)
 720 {
 721         g_debug("RoamSphere: update_errors - polys=%d", sphere->polys);
 722         GPtrArray *tris = g_pqueue_get_array(sphere->triangles);
 723         GPtrArray *dias = g_pqueue_get_array(sphere->diamonds);
 724
 725         roam_sphere_update_view(sphere);
 726
 727         for (int i = 0; i < tris->len; i++) {
 728                 RoamTriangle *triangle = tris->pdata[i];
 729                 roam_triangle_update_errors(triangle, sphere);
 730                 g_pqueue_priority_changed(sphere->triangles, triangle->handle);
 731         }
 732
 733         for (int i = 0; i < dias->len; i++) {
 734                 RoamDiamond *diamond = dias->pdata[i];
 735                 roam_diamond_update_errors(diamond, sphere);
 736                 g_pqueue_priority_changed(sphere->diamonds, diamond->handle);
 737         }
 738
 739         g_ptr_array_free(tris, TRUE);
 740         g_ptr_array_free(dias, TRUE);
 741 }
 742
 743 /**
 744  * roam_sphere_split_one
 745  * @sphere: the sphere
 746  *
 747  * Split the triangle with the greatest error.
 748  */
 749 void roam_sphere_split_one(RoamSphere *sphere)
 750 {
 751         RoamTriangle *to_split = g_pqueue_peek(sphere->triangles);
 752         if (!to_split) return;
 753         roam_triangle_split(to_split, sphere);
 754 }
 755
 756 /**
 757  * roam_sphere_merge_one
 758  * @sphere: the sphere
 759  *
 760  * Merge the diamond with the lowest error.
 761  */
 762 void roam_sphere_merge_one(RoamSphere *sphere)
 763 {
 764         RoamDiamond *to_merge = g_pqueue_peek(sphere->diamonds);
 765         if (!to_merge) return;
 766         roam_diamond_merge(to_merge, sphere);
 767 }
 768
 769 /**
 770  * roam_sphere_split_merge
 771  * @sphere: the sphere
 772  *
 773  * Perform a predetermined number split-merge iterations.
 774  *
 775  * Returns: the number splits and merges done
 776  */
 777 gint roam_sphere_split_merge(RoamSphere *sphere)
 778 {
 779         gint iters = 0, max_iters = 500;
 780         //gint target = 4000;
 781         gint target = 2000;
 782         //gint target = 500;
 783
 784         if (!sphere->view)
 785                 return 0;
 786
 787         if (target - sphere->polys > 100) {
 788                 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, sphere->polys);
 789                 while (sphere->polys < target && iters++ < max_iters)
 790                         roam_sphere_split_one(sphere);
 791         }
 792
 793         if (sphere->polys - target > 100) {
 794                 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", sphere->polys, target);
 795                 while (sphere->polys > target && iters++ < max_iters)
 796                         roam_sphere_merge_one(sphere);
 797         }
 798
 799         while (((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error >
 800                ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error &&
 801                iters++ < max_iters) {
 802                 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
 803                 //              ((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error,
 804                 //              ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error,
 805                 //              iters-1, max_iters);
 806                 roam_sphere_merge_one(sphere);
 807                 roam_sphere_split_one(sphere);
 808         }
 809
 810         return iters;
 811 }
 812
 813 /**
 814  * roam_sphere_draw:
 815  * @sphere: the sphere
 816  *
 817  * Draw the sphere. Use for debugging.
 818  */
 819 void roam_sphere_draw(RoamSphere *sphere)
 820 {
 821         g_debug("RoamSphere: draw");
 822         g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw, NULL);
 823 }
 824
 825 /**
 826  * roam_sphere_draw_normals
 827  * @sphere: the sphere
 828  *
 829  * Draw all the surface normal vectors for the sphere. Used while debugging.
 830  */
 831 void roam_sphere_draw_normals(RoamSphere *sphere)
 832 {
 833         g_debug("RoamSphere: draw_normal");
 834         g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 835 }
 836
 837 static GList *_roam_sphere_get_leaves(RoamTriangle *triangle, GList *list, gboolean all)
 838 {
 839         if (triangle->kids[0] && triangle->kids[1]) {
 840                 if (all) list = g_list_prepend(list, triangle);
 841                 list = _roam_sphere_get_leaves(triangle->kids[0], list, all);
 842                 list = _roam_sphere_get_leaves(triangle->kids[1], list, all);
 843                 return list;
 844         } else {
 845                 return g_list_prepend(list, triangle);
 846         }
 847 }
 848
 849 static GList *_roam_sphere_get_intersect_rec(RoamTriangle *triangle, GList *list,
 850                 gboolean all, gdouble n, gdouble s, gdouble e, gdouble w)
 851 {
 852         gdouble tn = triangle->edge.n;
 853         gdouble ts = triangle->edge.s;
 854         gdouble te = triangle->edge.e;
 855         gdouble tw = triangle->edge.w;
 856
 857         gboolean debug = FALSE  &&
 858                 n==90 && s==45 && e==-90 && w==-180 &&
 859                 ts > 44 && ts < 46;
 860
 861         if (debug)
 862                 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
 863                             triangle, tn,   s,   ts,   n,   te,   w,   tw,   e);
 864         if (tn <= s || ts >= n || te <= w || tw >= e) {
 865                 /* No intersect */
 866                 if (debug) g_message("no intersect");
 867                 return list;
 868         } else if (tn <= n && ts >= s && te <= e && tw >= w) {
 869                 /* Triangle is completely contained */
 870                 if (debug) g_message("contained");
 871                 if (all) list = g_list_prepend(list, triangle);
 872                 return _roam_sphere_get_leaves(triangle, list, all);
 873         } else if (triangle->kids[0] && triangle->kids[1]) {
 874                 /* Paritial intersect with children */
 875                 if (debug) g_message("edge w/ child");
 876                 if (all) list = g_list_prepend(list, triangle);
 877                 list = _roam_sphere_get_intersect_rec(triangle->kids[0], list, all, n, s, e, w);
 878                 list = _roam_sphere_get_intersect_rec(triangle->kids[1], list, all, n, s, e, w);
 879                 return list;
 880         } else {
 881                 /* This triangle is an edge case */
 882                 if (debug) g_message("edge");
 883                 return g_list_prepend(list, triangle);
 884         }
 885 }
 886
 887 /**
 888  * roam_sphere_get_intersect
 889  * @sphere: the sphere
 890  * @all: TRUE if non-leaf triangle should be returned as well
 891  * @n: the northern edge
 892  * @s: the southern edge
 893  * @e: the eastern edge
 894  * @w: the western edge
 895  *
 896  * Lookup triangles withing the sphere that intersect a given lat-lon box.
 897  *
 898  * Returns: the list of intersecting triangles.
 899  */
 900 /* Warning: This grabs pointers to triangles which can be changed by other
 901  * calls, e.g. split_merge. If you use this, you need to do some locking to
 902  * prevent the returned list from becomming stale. */
 903 GList *roam_sphere_get_intersect(RoamSphere *sphere, gboolean all,
 904                 gdouble n, gdouble s, gdouble e, gdouble w)
 905 {
 906         /* I think this is correct..
 907          * i_cost = cost for triangle-rectagnle intersect test
 908          * time = n_tiles * 2*tris_per_tile * i_cost
 909          * time = 30      * 2*333           * i_cost = 20000 * i_cost */
 910         GList *list = NULL;
 911         for (int i = 0; i < G_N_ELEMENTS(sphere->roots); i++)
 912                 list = _roam_sphere_get_intersect_rec(sphere->roots[i],
 913                                 list, all, n, s, e, w);
 914         return list;
 915 }
 916
 917 static void roam_sphere_free_tri(RoamTriangle *triangle)
 918 {
 919         if (--triangle->p.l->tris == 0) g_free(triangle->p.l);
 920         if (--triangle->p.m->tris == 0) g_free(triangle->p.m);
 921         if (--triangle->p.r->tris == 0) g_free(triangle->p.r);
 922         roam_triangle_free(triangle);
 923 }
 924
 925 /**
 926  * roam_sphere_free
 927  * @sphere: the sphere
 928  *
 929  * Free data associated with a sphere
 930  */
 931 void roam_sphere_free(RoamSphere *sphere)
 932 {
 933         g_debug("RoamSphere: free");
 934         /* Slow method, but it should work */
 935         while (sphere->polys > 8)
 936                 roam_sphere_merge_one(sphere);
 937         /* TODO: free points */
 938         g_pqueue_foreach(sphere->triangles, (GFunc)roam_sphere_free_tri, NULL);
 939         g_pqueue_free(sphere->triangles);
 940         g_pqueue_free(sphere->diamonds);
 941         g_free(sphere->view);
 942         g_free(sphere);
 943 }