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 static RoamPoint *roam_point_dup(RoamPoint *point)
  88 {
  89         RoamPoint *new = g_memdup(point, sizeof(RoamPoint));
  90         new->tris = 0;
  91         return new;
  92 }
  93
  94 /**
  95  * roam_point_add_triangle:
  96  * @point:    the point
  97  * @triangle: the to add
  98  *
  99  * Associating a triangle with a point and update it's vertex normal.
 100  */
 101 void roam_point_add_triangle(RoamPoint *point, RoamTriangle *triangle)
 102 {
 103         for (int i = 0; i < 3; i++) {
 104                 point->norm[i] *= point->tris;
 105                 point->norm[i] += triangle->norm[i];
 106         }
 107         point->tris++;
 108         for (int i = 0; i < 3; i++)
 109                 point->norm[i] /= point->tris;
 110 }
 111
 112 /**
 113  * roam_point_remove_triangle:
 114  * @point:    the point
 115  * @triangle: the to add
 116  *
 117  * Un-associating a triangle with a point and update it's vertex normal.
 118  */
 119 void roam_point_remove_triangle(RoamPoint *point, RoamTriangle *triangle)
 120 {
 121         for (int i = 0; i < 3; i++) {
 122                 point->norm[i] *= point->tris;
 123                 point->norm[i] -= triangle->norm[i];
 124         }
 125         point->tris--;
 126         if (point->tris)
 127                 for (int i = 0; i < 3; i++)
 128                         point->norm[i] /= point->tris;
 129 }
 130
 131 /**
 132  * roam_point_update_height:
 133  * @point: the point
 134  *
 135  * Update the height (elevation) of a point based on the current height function
 136  */
 137 void roam_point_update_height(RoamPoint *point)
 138 {
 139         if (point->height_func) {
 140                 gdouble elev = point->height_func(
 141                                 point->lat, point->lon, point->height_data);
 142                 lle2xyz(point->lat, point->lon, elev,
 143                                 &point->x, &point->y, &point->z);
 144         }
 145 }
 146
 147 /**
 148  * roam_point_update_projection:
 149  * @point: the point
 150  * @view:  the view to use when projecting the point
 151  *
 152  * Updated the screen-space projection of a point.
 153  */
 154 void roam_point_update_projection(RoamPoint *point, RoamView *view)
 155 {
 156         static int count   = 0;
 157         static int version = 0;
 158         if (version != view->version) {
 159                 g_debug("RoamPoint: Projected %d points", count);
 160                 count   = 0;
 161                 version = view->version;
 162         }
 163
 164         if (point->pversion != view->version) {
 165                 /* Cache projection */
 166                 gluProject(point->x, point->y, point->z,
 167                         view->model, view->proj, view->view,
 168                         &point->px, &point->py, &point->pz);
 169                 point->pversion = view->version;
 170                 count++;
 171         }
 172 }
 173
 174 /****************
 175  * RoamTriangle *
 176  ****************/
 177 /**
 178  * roam_triangle_new:
 179  * @l: the left point
 180  * @m: the middle point
 181  * @r: the right point
 182  *
 183  * Create a new triangle consisting of three points.
 184  *
 185  * Returns: the new triangle
 186  */
 187 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
 188 {
 189         RoamTriangle *triangle = g_new0(RoamTriangle, 1);
 190
 191         triangle->error = 0;
 192         triangle->p.l = l;
 193         triangle->p.m = m;
 194         triangle->p.r = r;
 195         triangle->split = roam_point_new(
 196                 (l->lat + r->lat)/2,
 197                 (ABS(l->lat) == 90 ? r->lon :
 198                  ABS(r->lat) == 90 ? l->lon :
 199                  lon_avg(l->lon, r->lon)),
 200                 (l->elev + r->elev)/2);
 201         /* TODO: Move this back to sphere, or actually use the nesting */
 202         triangle->split->height_func = m->height_func;
 203         triangle->split->height_data = m->height_data;
 204         roam_point_update_height(triangle->split);
 205         //if ((float)triangle->split->lat > 44 && (float)triangle->split->lat < 46)
 206         //      g_debug("RoamTriangle: new - (l,m,r,split).lats = %7.2f %7.2f %7.2f %7.2f",
 207         //                      l->lat, m->lat, r->lat, triangle->split->lat);
 208         //if ((float)l->lat == (float)r->lat &&
 209         //    (float)triangle->split->lat != (float)l->lat)
 210         //      g_warning("RoamTriangle: new - split.lat=%f != (l=r).lat=%f",
 211         //              triangle->split->lat, l->lat);
 212
 213         /* Update normal */
 214         double pa[3];
 215         double pb[3];
 216         pa[0] = triangle->p.l->x - triangle->p.m->x;
 217         pa[1] = triangle->p.l->y - triangle->p.m->y;
 218         pa[2] = triangle->p.l->z - triangle->p.m->z;
 219
 220         pb[0] = triangle->p.r->x - triangle->p.m->x;
 221         pb[1] = triangle->p.r->y - triangle->p.m->y;
 222         pb[2] = triangle->p.r->z - triangle->p.m->z;
 223
 224         triangle->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 225         triangle->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 226         triangle->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 227
 228         double total = sqrt(triangle->norm[0] * triangle->norm[0] +
 229                             triangle->norm[1] * triangle->norm[1] +
 230                             triangle->norm[2] * triangle->norm[2]);
 231
 232         triangle->norm[0] /= total;
 233         triangle->norm[1] /= total;
 234         triangle->norm[2] /= total;
 235
 236         /* Store bounding box, for get_intersect */
 237         RoamPoint *p[] = {l,m,r};
 238         triangle->edge.n =  -90; triangle->edge.s =  90;
 239         triangle->edge.e = -180; triangle->edge.w = 180;
 240         gboolean maxed = FALSE;
 241         for (int i = 0; i < G_N_ELEMENTS(p); i++) {
 242                 triangle->edge.n = MAX(triangle->edge.n, p[i]->lat);
 243                 triangle->edge.s = MIN(triangle->edge.s, p[i]->lat);
 244                 if (p[i]->lat == 90 || p[i]->lat == -90)
 245                         continue;
 246                 if (p[i]->lon == 180) {
 247                         maxed = TRUE;
 248                         continue;
 249                 }
 250                 triangle->edge.e = MAX(triangle->edge.e, p[i]->lon);
 251                 triangle->edge.w = MIN(triangle->edge.w, p[i]->lon);
 252         }
 253         if (maxed) {
 254                 if (triangle->edge.e < 0)
 255                         triangle->edge.w = -180;
 256                 else
 257                         triangle->edge.e =  180;
 258         }
 259
 260         //g_message("roam_triangle_new: %p", triangle);
 261         return triangle;
 262 }
 263
 264 /**
 265  * roam_triangle_free:
 266  * @triangle: the triangle
 267  *
 268  * Free data associated with a triangle
 269  */
 270 void roam_triangle_free(RoamTriangle *triangle)
 271 {
 272         g_free(triangle->split);
 273         g_free(triangle);
 274 }
 275
 276 /**
 277  * roam_triangle_add:
 278  * @triangle: the triangle
 279  * @left:     the left neighbor
 280  * @base:     the base neighbor
 281  * @right:    the right neighbor
 282  * @sphere:   the sphere to add the triangle to
 283  *
 284  * Add a triangle into the sphere's mesh using the given neighbors.
 285  */
 286 void roam_triangle_add(RoamTriangle *triangle,
 287                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 288                 RoamSphere *sphere)
 289 {
 290         triangle->t.l = left;
 291         triangle->t.b = base;
 292         triangle->t.r = right;
 293
 294         roam_point_add_triangle(triangle->p.l, triangle);
 295         roam_point_add_triangle(triangle->p.m, triangle);
 296         roam_point_add_triangle(triangle->p.r, triangle);
 297
 298         if (sphere->view)
 299                 roam_triangle_update_errors(triangle, sphere);
 300
 301         triangle->handle = g_pqueue_push(sphere->triangles, triangle);
 302 }
 303
 304 /**
 305  * roam_triangle_remove:
 306  * @triangle: the triangle
 307  * @sphere:   the sphere to remove the triangle from
 308  *
 309  * Remove a triangle from a sphere's mesh.
 310  */
 311 void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
 312 {
 313         /* Update vertex normals */
 314         roam_point_remove_triangle(triangle->p.l, triangle);
 315         roam_point_remove_triangle(triangle->p.m, triangle);
 316         roam_point_remove_triangle(triangle->p.r, triangle);
 317
 318         g_pqueue_remove(sphere->triangles, triangle->handle);
 319 }
 320
 321 static void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
 322 {
 323         if      (neigh->t.l == old) neigh->t.l = new;
 324         else if (neigh->t.b == old) neigh->t.b = new;
 325         else if (neigh->t.r == old) neigh->t.r = new;
 326         else g_assert_not_reached();
 327 }
 328
 329 static gboolean roam_point_visible(RoamPoint *triangle, RoamSphere *sphere)
 330 {
 331         gint *view = sphere->view->view;
 332         return triangle->px > view[0] && triangle->px < view[2] &&
 333                triangle->py > view[1] && triangle->py < view[3] &&
 334                triangle->pz > 0       && triangle->pz < 1;
 335 }
 336 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
 337 {
 338         /* Do this with a bounding box */
 339         return roam_point_visible(triangle->p.l, sphere) ||
 340                roam_point_visible(triangle->p.m, sphere) ||
 341                roam_point_visible(triangle->p.r, sphere);
 342 }
 343
 344 /**
 345  * roam_triangle_update_errors:
 346  * @triangle: the triangle
 347  * @sphere:   the sphere to use when updating errors
 348  *
 349  * Update the error value associated with a triangle. Called when the view
 350  * changes.
 351  */
 352 void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
 353 {
 354         /* Update points */
 355         roam_point_update_projection(triangle->p.l, sphere->view);
 356         roam_point_update_projection(triangle->p.m, sphere->view);
 357         roam_point_update_projection(triangle->p.r, sphere->view);
 358
 359         /* Not exactly correct, could be out on both sides (middle in) */
 360         if (!roam_triangle_visible(triangle, sphere)) {
 361                 triangle->error = -1;
 362         } else {
 363                 roam_point_update_projection(triangle->split, sphere->view);
 364                 RoamPoint *l = triangle->p.l;
 365                 RoamPoint *m = triangle->p.m;
 366                 RoamPoint *r = triangle->p.r;
 367                 RoamPoint *split = triangle->split;
 368
 369                 /*               l-r midpoint        projected l-r midpoint */
 370                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 371                 gdouble pydist = (l->py + r->py)/2 - split->py;
 372
 373                 triangle->error = sqrt(pxdist*pxdist + pydist*pydist);
 374
 375                 /* Multiply by size of triangle */
 376                 double size = -( l->px * (m->py - r->py) +
 377                                  m->px * (r->py - l->py) +
 378                                  r->px * (l->py - m->py) ) / 2.0;
 379
 380                 /* Size < 0 == backface */
 381                 //if (size < 0)
 382                 //      triangle->error *= -1;
 383                 triangle->error *= size;
 384         }
 385 }
 386
 387 /**
 388  * roam_triangle_split:
 389  * @triangle: the triangle
 390  * @sphere:   the sphere
 391  *
 392  * Split a triangle into two child triangles and update the sphere.
 393  */
 394 void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
 395 {
 396         //g_message("roam_triangle_split: %p, e=%f\n", triangle, triangle->error);
 397
 398         sphere->polys += 2;
 399
 400         if (triangle != triangle->t.b->t.b)
 401                 roam_triangle_split(triangle->t.b, sphere);
 402         if (triangle != triangle->t.b->t.b)
 403                 g_assert_not_reached();
 404
 405         RoamTriangle *base = triangle->t.b;
 406
 407         /* Add new triangles */
 408         RoamPoint *mid = triangle->split;
 409         RoamTriangle *sl = triangle->kids[0] = roam_triangle_new(triangle->p.m, mid, triangle->p.l); // triangle Left
 410         RoamTriangle *sr = triangle->kids[1] = roam_triangle_new(triangle->p.r, mid, triangle->p.m); // triangle Right
 411         RoamTriangle *bl = base->kids[0] = roam_triangle_new(base->p.m, mid, base->p.l); // Base Left
 412         RoamTriangle *br = base->kids[1] = roam_triangle_new(base->p.r, mid, base->p.m); // Base Right
 413
 414         /*                triangle,l,  base,      r,  sphere */
 415         roam_triangle_add(sl, sr, triangle->t.l, br, sphere);
 416         roam_triangle_add(sr, bl, triangle->t.r, sl, sphere);
 417         roam_triangle_add(bl, br, base->t.l, sr, sphere);
 418         roam_triangle_add(br, sl, base->t.r, bl, sphere);
 419
 420         roam_triangle_sync_neighbors(sl, triangle, triangle->t.l);
 421         roam_triangle_sync_neighbors(sr, triangle, triangle->t.r);
 422         roam_triangle_sync_neighbors(bl, base, base->t.l);
 423         roam_triangle_sync_neighbors(br, base, base->t.r);
 424
 425         /* Remove old triangles */
 426         roam_triangle_remove(triangle, sphere);
 427         roam_triangle_remove(base, sphere);
 428
 429         /* Add/Remove diamonds */
 430         RoamDiamond *diamond = roam_diamond_new(triangle, base, sl, sr, bl, br);
 431         roam_diamond_update_errors(diamond, sphere);
 432         roam_diamond_add(diamond, sphere);
 433         roam_diamond_remove(triangle->parent, sphere);
 434         roam_diamond_remove(base->parent, sphere);
 435 }
 436
 437 /**
 438  * roam_triangle_draw:
 439  * @triangle: the triangle
 440  *
 441  * Draw the triangle. Use for debugging.
 442  */
 443 void roam_triangle_draw(RoamTriangle *triangle)
 444 {
 445         glBegin(GL_TRIANGLES);
 446         glNormal3dv(triangle->p.r->norm); glVertex3dv((double*)triangle->p.r);
 447         glNormal3dv(triangle->p.m->norm); glVertex3dv((double*)triangle->p.m);
 448         glNormal3dv(triangle->p.l->norm); glVertex3dv((double*)triangle->p.l);
 449         glEnd();
 450         return;
 451 }
 452
 453 /**
 454  * roam_triangle_draw_normal:
 455  * @triangle: the triangle
 456  *
 457  * Draw a normal vector for the triangle. Used while debugging.
 458  */
 459 void roam_triangle_draw_normal(RoamTriangle *triangle)
 460 {
 461         double center[] = {
 462                 (triangle->p.l->x + triangle->p.m->x + triangle->p.r->x)/3.0,
 463                 (triangle->p.l->y + triangle->p.m->y + triangle->p.r->y)/3.0,
 464                 (triangle->p.l->z + triangle->p.m->z + triangle->p.r->z)/3.0,
 465         };
 466         double end[] = {
 467                 center[0]+triangle->norm[0]*2000000,
 468                 center[1]+triangle->norm[1]*2000000,
 469                 center[2]+triangle->norm[2]*2000000,
 470         };
 471         glBegin(GL_LINES);
 472         glVertex3dv(center);
 473         glVertex3dv(end);
 474         glEnd();
 475 }
 476
 477 /***************
 478  * RoamDiamond *
 479  ***************/
 480 /**
 481  * roam_diamond_new:
 482  * @parent0: a parent triangle
 483  * @parent1: a parent triangle
 484  * @kid0:    a child triangle
 485  * @kid1:    a child triangle
 486  * @kid2:    a child triangle
 487  * @kid3:    a child triangle
 488  *
 489  * Create a diamond to store information about two split triangles.
 490  *
 491  * Returns: the new diamond
 492  */
 493 RoamDiamond *roam_diamond_new(
 494                 RoamTriangle *parent0, RoamTriangle *parent1,
 495                 RoamTriangle *kid0, RoamTriangle *kid1,
 496                 RoamTriangle *kid2, RoamTriangle *kid3)
 497 {
 498         RoamDiamond *diamond = g_new0(RoamDiamond, 1);
 499
 500         diamond->kids[0] = kid0;
 501         diamond->kids[1] = kid1;
 502         diamond->kids[2] = kid2;
 503         diamond->kids[3] = kid3;
 504
 505         kid0->parent = diamond;
 506         kid1->parent = diamond;
 507         kid2->parent = diamond;
 508         kid3->parent = diamond;
 509
 510         diamond->parents[0] = parent0;
 511         diamond->parents[1] = parent1;
 512
 513         return diamond;
 514 }
 515
 516 /**
 517  * roam_diamond_add:
 518  * @diamond: the diamond
 519  * @sphere:  the sphere to add the diamond to
 520  *
 521  * Add a diamond into the sphere's pool of diamonds. It will be check for
 522  * possible merges.
 523  */
 524 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere)
 525 {
 526         diamond->active = TRUE;
 527         diamond->error  = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
 528         diamond->handle = g_pqueue_push(sphere->diamonds, diamond);
 529 }
 530
 531 /**
 532  * roam_diamond_remove:
 533  * @diamond: the diamond
 534  * @sphere:  the sphere to remove the diamond from
 535  *
 536  * Remove a diamond from the sphere's pool of diamonds.
 537  */
 538 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere)
 539 {
 540         if (diamond && diamond->active) {
 541                 diamond->active = FALSE;
 542                 g_pqueue_remove(sphere->diamonds, diamond->handle);
 543         }
 544 }
 545
 546 /**
 547  * roam_diamond_merge:
 548  * @diamond: the diamond
 549  * @sphere:  the sphere
 550  *
 551  * "Merge" a diamond back into two parent triangles. The original two triangles
 552  * are added back into the sphere and the four child triangles as well as the
 553  * diamond are removed.
 554  */
 555 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
 556 {
 557         //g_message("roam_diamond_merge: %p, e=%f\n", diamond, diamond->error);
 558
 559         sphere->polys -= 2;
 560
 561         /* TODO: pick the best split */
 562         RoamTriangle **kids = diamond->kids;
 563
 564         /* Create triangles */
 565         RoamTriangle *triangle  = diamond->parents[0];
 566         RoamTriangle *base = diamond->parents[1];
 567
 568         roam_triangle_add(triangle,  kids[0]->t.b, base, kids[1]->t.b, sphere);
 569         roam_triangle_add(base, kids[2]->t.b, triangle,  kids[3]->t.b, sphere);
 570
 571         roam_triangle_sync_neighbors(triangle,  kids[0], kids[0]->t.b);
 572         roam_triangle_sync_neighbors(triangle,  kids[1], kids[1]->t.b);
 573         roam_triangle_sync_neighbors(base, kids[2], kids[2]->t.b);
 574         roam_triangle_sync_neighbors(base, kids[3], kids[3]->t.b);
 575
 576         /* Remove triangles */
 577         roam_triangle_remove(kids[0], sphere);
 578         roam_triangle_remove(kids[1], sphere);
 579         roam_triangle_remove(kids[2], sphere);
 580         roam_triangle_remove(kids[3], sphere);
 581
 582         /* Clear kids */
 583         triangle->kids[0]  = triangle->kids[1]  = NULL;
 584         base->kids[0] = base->kids[1] = NULL;
 585
 586         /* Add/Remove triangles */
 587         if (triangle->t.l->t.l == triangle->t.r->t.r &&
 588             triangle->t.l->t.l != triangle && triangle->parent) {
 589                 roam_diamond_update_errors(triangle->parent, sphere);
 590                 roam_diamond_add(triangle->parent, sphere);
 591         }
 592
 593         if (base->t.l->t.l == base->t.r->t.r &&
 594             base->t.l->t.l != base && base->parent) {
 595                 roam_diamond_update_errors(base->parent, sphere);
 596                 roam_diamond_add(base->parent, sphere);
 597         }
 598
 599         /* Remove and free diamond and child triangles */
 600         roam_diamond_remove(diamond, sphere);
 601         g_assert(diamond->kids[0]->p.m == diamond->kids[1]->p.m &&
 602                  diamond->kids[1]->p.m == diamond->kids[2]->p.m &&
 603                  diamond->kids[2]->p.m == diamond->kids[3]->p.m);
 604         g_assert(diamond->kids[0]->p.m->tris == 0);
 605         roam_triangle_free(diamond->kids[0]);
 606         roam_triangle_free(diamond->kids[1]);
 607         roam_triangle_free(diamond->kids[2]);
 608         roam_triangle_free(diamond->kids[3]);
 609         g_free(diamond);
 610 }
 611
 612 /**
 613  * roam_diamond_update_errors:
 614  * @diamond: the diamond
 615  * @sphere:  the sphere to use when updating errors
 616  *
 617  * Update the error value associated with a diamond. Called when the view
 618  * changes.
 619  */
 620 void roam_diamond_update_errors(RoamDiamond *diamond, RoamSphere *sphere)
 621 {
 622         roam_triangle_update_errors(diamond->parents[0], sphere);
 623         roam_triangle_update_errors(diamond->parents[1], sphere);
 624         diamond->error = MAX(diamond->parents[0]->error, diamond->parents[1]->error);
 625 }
 626
 627 /**************
 628  * RoamSphere *
 629  **************/
 630 /**
 631  * roam_sphere_new:
 632  *
 633  * Create a new sphere
 634  *
 635  * Returns: the sphere
 636  */
 637 RoamSphere *roam_sphere_new()
 638 {
 639         RoamSphere *sphere = g_new0(RoamSphere, 1);
 640         sphere->polys       = 8;
 641         sphere->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 642         sphere->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 643
 644         RoamPoint *vertexes[] = {
 645                 roam_point_new( 90,   0,  0), // 0 (North)
 646                 roam_point_new(-90,   0,  0), // 1 (South)
 647                 roam_point_new(  0,   0,  0), // 2 (Europe/Africa)
 648                 roam_point_new(  0,  90,  0), // 3 (Asia,East)
 649                 roam_point_new(  0, 180,  0), // 4 (Pacific)
 650                 roam_point_new(  0, -90,  0), // 5 (Americas,West)
 651         };
 652         int _triangles[][2][3] = {
 653                 /*lv mv rv   ln, bn, rn */
 654                 {{2,0,3}, {3, 4, 1}}, // 0
 655                 {{3,0,4}, {0, 5, 2}}, // 1
 656                 {{4,0,5}, {1, 6, 3}}, // 2
 657                 {{5,0,2}, {2, 7, 0}}, // 3
 658                 {{3,1,2}, {5, 0, 7}}, // 4
 659                 {{4,1,3}, {6, 1, 4}}, // 5
 660                 {{5,1,4}, {7, 2, 5}}, // 6
 661                 {{2,1,5}, {4, 3, 6}}, // 7
 662         };
 663
 664         for (int i = 0; i < 6; i++)
 665                 roam_point_update_height(vertexes[i]);
 666         for (int i = 0; i < 8; i++)
 667                 sphere->roots[i] = roam_triangle_new(
 668                         vertexes[_triangles[i][0][0]],
 669                         vertexes[_triangles[i][0][1]],
 670                         vertexes[_triangles[i][0][2]]);
 671         for (int i = 0; i < 8; i++)
 672                 roam_triangle_add(sphere->roots[i],
 673                         sphere->roots[_triangles[i][1][0]],
 674                         sphere->roots[_triangles[i][1][1]],
 675                         sphere->roots[_triangles[i][1][2]],
 676                         sphere);
 677         for (int i = 0; i < 8; i++)
 678                 g_debug("RoamSphere: new - %p edge=%f,%f,%f,%f", sphere->roots[i],
 679                                 sphere->roots[i]->edge.n,
 680                                 sphere->roots[i]->edge.s,
 681                                 sphere->roots[i]->edge.e,
 682                                 sphere->roots[i]->edge.w);
 683
 684         return sphere;
 685 }
 686
 687 /**
 688  * roam_sphere_update_view
 689  * @sphere: the sphere
 690  *
 691  * Recreate the sphere's view matrices based on the current OpenGL state.
 692  */
 693 void roam_sphere_update_view(RoamSphere *sphere)
 694 {
 695         if (!sphere->view)
 696                 sphere->view = g_new0(RoamView, 1);
 697         glGetDoublev (GL_MODELVIEW_MATRIX,  sphere->view->model);
 698         glGetDoublev (GL_PROJECTION_MATRIX, sphere->view->proj);
 699         glGetIntegerv(GL_VIEWPORT,          sphere->view->view);
 700         sphere->view->version++;
 701 }
 702
 703 /**
 704  * roam_sphere_update_errors
 705  * @sphere: the sphere
 706  *
 707  * Update triangle and diamond errors in the sphere.
 708  */
 709 void roam_sphere_update_errors(RoamSphere *sphere)
 710 {
 711         g_debug("RoamSphere: update_errors - polys=%d", sphere->polys);
 712         GPtrArray *tris = g_pqueue_get_array(sphere->triangles);
 713         GPtrArray *dias = g_pqueue_get_array(sphere->diamonds);
 714
 715         roam_sphere_update_view(sphere);
 716
 717         for (int i = 0; i < tris->len; i++) {
 718                 RoamTriangle *triangle = tris->pdata[i];
 719                 roam_triangle_update_errors(triangle, sphere);
 720                 g_pqueue_priority_changed(sphere->triangles, triangle->handle);
 721         }
 722
 723         for (int i = 0; i < dias->len; i++) {
 724                 RoamDiamond *diamond = dias->pdata[i];
 725                 roam_diamond_update_errors(diamond, sphere);
 726                 g_pqueue_priority_changed(sphere->diamonds, diamond->handle);
 727         }
 728
 729         g_ptr_array_free(tris, TRUE);
 730         g_ptr_array_free(dias, TRUE);
 731 }
 732
 733 /**
 734  * roam_sphere_split_one
 735  * @sphere: the sphere
 736  *
 737  * Split the triangle with the greatest error.
 738  */
 739 void roam_sphere_split_one(RoamSphere *sphere)
 740 {
 741         RoamTriangle *to_split = g_pqueue_peek(sphere->triangles);
 742         if (!to_split) return;
 743         roam_triangle_split(to_split, sphere);
 744 }
 745
 746 /**
 747  * roam_sphere_merge_one
 748  * @sphere: the sphere
 749  *
 750  * Merge the diamond with the lowest error.
 751  */
 752 void roam_sphere_merge_one(RoamSphere *sphere)
 753 {
 754         RoamDiamond *to_merge = g_pqueue_peek(sphere->diamonds);
 755         if (!to_merge) return;
 756         roam_diamond_merge(to_merge, sphere);
 757 }
 758
 759 /**
 760  * roam_sphere_split_merge
 761  * @sphere: the sphere
 762  *
 763  * Perform a predetermined number split-merge iterations.
 764  *
 765  * Returns: the number splits and merges done
 766  */
 767 gint roam_sphere_split_merge(RoamSphere *sphere)
 768 {
 769         gint iters = 0, max_iters = 500;
 770         //gint target = 4000;
 771         gint target = 2000;
 772         //gint target = 500;
 773
 774         if (!sphere->view)
 775                 return 0;
 776
 777         if (target - sphere->polys > 100) {
 778                 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, sphere->polys);
 779                 while (sphere->polys < target && iters++ < max_iters)
 780                         roam_sphere_split_one(sphere);
 781         }
 782
 783         if (sphere->polys - target > 100) {
 784                 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", sphere->polys, target);
 785                 while (sphere->polys > target && iters++ < max_iters)
 786                         roam_sphere_merge_one(sphere);
 787         }
 788
 789         while (((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error >
 790                ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error &&
 791                iters++ < max_iters) {
 792                 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
 793                 //              ((RoamTriangle*)g_pqueue_peek(sphere->triangles))->error,
 794                 //              ((RoamDiamond *)g_pqueue_peek(sphere->diamonds ))->error,
 795                 //              iters-1, max_iters);
 796                 roam_sphere_merge_one(sphere);
 797                 roam_sphere_split_one(sphere);
 798         }
 799
 800         return iters;
 801 }
 802
 803 /**
 804  * roam_sphere_draw:
 805  * @sphere: the sphere
 806  *
 807  * Draw the sphere. Use for debugging.
 808  */
 809 void roam_sphere_draw(RoamSphere *sphere)
 810 {
 811         g_debug("RoamSphere: draw");
 812         g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw, NULL);
 813 }
 814
 815 /**
 816  * roam_sphere_draw_normals
 817  * @sphere: the sphere
 818  *
 819  * Draw all the surface normal vectors for the sphere. Used while debugging.
 820  */
 821 void roam_sphere_draw_normals(RoamSphere *sphere)
 822 {
 823         g_debug("RoamSphere: draw_normal");
 824         g_pqueue_foreach(sphere->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 825 }
 826
 827 static GList *_roam_sphere_get_leaves(RoamTriangle *triangle, GList *list, gboolean all)
 828 {
 829         if (triangle->kids[0] && triangle->kids[1]) {
 830                 if (all) list = g_list_prepend(list, triangle);
 831                 list = _roam_sphere_get_leaves(triangle->kids[0], list, all);
 832                 list = _roam_sphere_get_leaves(triangle->kids[1], list, all);
 833                 return list;
 834         } else {
 835                 return g_list_prepend(list, triangle);
 836         }
 837 }
 838
 839 static GList *_roam_sphere_get_intersect_rec(RoamTriangle *triangle, GList *list,
 840                 gboolean all, gdouble n, gdouble s, gdouble e, gdouble w)
 841 {
 842         gdouble tn = triangle->edge.n;
 843         gdouble ts = triangle->edge.s;
 844         gdouble te = triangle->edge.e;
 845         gdouble tw = triangle->edge.w;
 846
 847         gboolean debug = FALSE  &&
 848                 n==90 && s==45 && e==-90 && w==-180 &&
 849                 ts > 44 && ts < 46;
 850
 851         if (debug)
 852                 g_message("t=%p: %f < %f || %f > %f || %f < %f || %f > %f",
 853                             triangle, tn,   s,   ts,   n,   te,   w,   tw,   e);
 854         if (tn < s || ts > n || te < w || tw > e) {
 855                 /* No intersect */
 856                 if (debug) g_message("no intersect");
 857                 return list;
 858         } else if (tn <= n && ts >= s && te <= e && tw >= w) {
 859                 /* Triangle is completely contained */
 860                 if (debug) g_message("contained");
 861                 if (all) list = g_list_prepend(list, triangle);
 862                 return _roam_sphere_get_leaves(triangle, list, all);
 863         } else if (triangle->kids[0] && triangle->kids[1]) {
 864                 /* Paritial intersect with children */
 865                 if (debug) g_message("edge w/ child");
 866                 if (all) list = g_list_prepend(list, triangle);
 867                 list = _roam_sphere_get_intersect_rec(triangle->kids[0], list, all, n, s, e, w);
 868                 list = _roam_sphere_get_intersect_rec(triangle->kids[1], list, all, n, s, e, w);
 869                 return list;
 870         } else {
 871                 /* This triangle is an edge case */
 872                 if (debug) g_message("edge");
 873                 return g_list_prepend(list, triangle);
 874         }
 875 }
 876
 877 /**
 878  * roam_sphere_get_intersect
 879  * @sphere: the sphere
 880  * @all: TRUE if non-leaf triangle should be returned as well
 881  * @n: the northern edge
 882  * @s: the southern edge
 883  * @e: the eastern edge
 884  * @w: the western edge
 885  *
 886  * Lookup triangles withing the sphere that intersect a given lat-lon box.
 887  *
 888  * Returns: the list of intersecting triangles.
 889  */
 890 /* Warning: This grabs pointers to triangles which can be changed by other
 891  * calls, e.g. split_merge. If you use this, you need to do some locking to
 892  * prevent the returned list from becomming stale. */
 893 GList *roam_sphere_get_intersect(RoamSphere *sphere, gboolean all,
 894                 gdouble n, gdouble s, gdouble e, gdouble w)
 895 {
 896         /* I think this is correct..
 897          * i_cost = cost for triangle-rectagnle intersect test
 898          * time = n_tiles * 2*tris_per_tile * i_cost
 899          * time = 30      * 2*333           * i_cost = 20000 * i_cost */
 900         GList *list = NULL;
 901         for (int i = 0; i < G_N_ELEMENTS(sphere->roots); i++)
 902                 list = _roam_sphere_get_intersect_rec(sphere->roots[i],
 903                                 list, all, n, s, e, w);
 904         return list;
 905 }
 906
 907 static void roam_sphere_free_tri(RoamTriangle *triangle)
 908 {
 909         if (--triangle->p.l->tris == 0) g_free(triangle->p.l);
 910         if (--triangle->p.m->tris == 0) g_free(triangle->p.m);
 911         if (--triangle->p.r->tris == 0) g_free(triangle->p.r);
 912         roam_triangle_free(triangle);
 913 }
 914
 915 /**
 916  * roam_sphere_free
 917  * @sphere: the sphere
 918  *
 919  * Free data associated with a sphere
 920  */
 921 void roam_sphere_free(RoamSphere *sphere)
 922 {
 923         g_debug("RoamSphere: free");
 924         /* Slow method, but it should work */
 925         while (sphere->polys > 8)
 926                 roam_sphere_merge_one(sphere);
 927         /* TODO: free points */
 928         g_pqueue_foreach(sphere->triangles, (GFunc)roam_sphere_free_tri, NULL);
 929         g_pqueue_free(sphere->triangles);
 930         g_pqueue_free(sphere->diamonds);
 931         g_free(sphere->view);
 932         g_free(sphere);
 933 }