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

   1 /*
   2  * Copyright (C) 2009 Andy Spencer <spenceal@rose-hulman.edu>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <glib.h>
  19 #include <math.h>
  20 #include <string.h>
  21 #include "gpqueue.h"
  22 #include <GL/gl.h>
  23 #include <GL/glu.h>
  24
  25 #include "gis-world.h"
  26
  27 #include "roam.h"
  28
  29
  30 /**
  31  * TODO:
  32  *   - Optimize for memory consumption
  33  *   - Profile for computation speed
  34  *   - Target polygon count/detail
  35  */
  36
  37 /* Misc */
  38 RoamView *roam_view_new()
  39 {
  40         return g_new0(RoamView, 1);
  41 }
  42 void roam_view_update(RoamView *view)
  43 {
  44         glGetDoublev (GL_MODELVIEW_MATRIX,  view->model);
  45         glGetDoublev (GL_PROJECTION_MATRIX, view->proj);
  46         glGetIntegerv(GL_VIEWPORT,          view->view);
  47         view->version++;
  48 }
  49
  50 /* For GPQueue comparators */
  51 static gint tri_cmp(RoamTriangle *a, RoamTriangle *b, gpointer data)
  52 {
  53         if      (a->error < b->error) return  1;
  54         else if (a->error > b->error) return -1;
  55         else                          return  0;
  56 }
  57 static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data)
  58 {
  59         if      (a->error < b->error) return -1;
  60         else if (a->error > b->error) return  1;
  61         else                          return  0;
  62 }
  63
  64 /*************
  65  * RoamPoint *
  66  *************/
  67 RoamPoint *roam_point_new(gdouble x, gdouble y, gdouble z)
  68 {
  69         RoamPoint *self = g_new0(RoamPoint, 1);
  70         self->x = x;
  71         self->y = y;
  72         self->z = z;
  73         /* For get_intersect */
  74         xyz2ll(x, y, z, &self->lat, &self->lon);
  75         return self;
  76 }
  77 RoamPoint *roam_point_dup(RoamPoint *self)
  78 {
  79         RoamPoint *new = g_memdup(self, sizeof(RoamPoint));
  80         new->tris = 0;
  81         return new;
  82 }
  83 void roam_point_add_triangle(RoamPoint *self, RoamTriangle *triangle)
  84 {
  85         for (int i = 0; i < 3; i++) {
  86                 self->norm[i] *= self->tris;
  87                 self->norm[i] += triangle->norm[i];
  88         }
  89         self->tris++;
  90         for (int i = 0; i < 3; i++)
  91                 self->norm[i] /= self->tris;
  92 }
  93 void roam_point_remove_triangle(RoamPoint *self, RoamTriangle *triangle)
  94 {
  95         for (int i = 0; i < 3; i++) {
  96                 self->norm[i] *= self->tris;
  97                 self->norm[i] -= triangle->norm[i];
  98         }
  99         self->tris--;
 100         if (self->tris)
 101                 for (int i = 0; i < 3; i++)
 102                         self->norm[i] /= self->tris;
 103 }
 104 void roam_point_update_height(RoamPoint *self)
 105 {
 106         if (self->height_func) {
 107                 gdouble elev = self->height_func(
 108                                 self->lat, self->lon, self->height_data);
 109                 lle2xyz(self->lat, self->lon, elev,
 110                                 &self->x, &self->y, &self->z);
 111         } else {
 112                 gdouble dist = sqrt(self->x * self->x +
 113                                     self->y * self->y +
 114                                     self->z * self->z);
 115                 self->x = self->x/dist * EARTH_R;
 116                 self->y = self->y/dist * EARTH_R;
 117                 self->z = self->z/dist * EARTH_R;
 118         }
 119 }
 120 void roam_point_update_projection(RoamPoint *self, RoamSphere *sphere)
 121 {
 122         static int count   = 0;
 123         static int version = 0;
 124         if (version != sphere->view->version) {
 125                 g_debug("Projected %d points", count);
 126                 count   = 0;
 127                 version = sphere->view->version;
 128         }
 129
 130         if (self->pversion != sphere->view->version) {
 131                 /* Cache projection */
 132                 gluProject(self->x, self->y, self->z,
 133                         sphere->view->model, sphere->view->proj, sphere->view->view,
 134                         &self->px, &self->py, &self->pz);
 135                 self->pversion = sphere->view->version;
 136                 count++;
 137         }
 138 }
 139
 140 /****************
 141  * RoamTriangle *
 142  ****************/
 143 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
 144 {
 145         RoamTriangle *self = g_new0(RoamTriangle, 1);
 146
 147         self->error = 0;
 148         self->p.l = l;
 149         self->p.m = m;
 150         self->p.r = r;
 151         self->split = roam_point_new(
 152                 (l->x + r->x)/2,
 153                 (l->y + r->y)/2,
 154                 (l->z + r->z)/2);
 155         /* TODO: Move this back to sphere, or actually use the nesting */
 156         self->split->height_func = m->height_func;
 157         self->split->height_data = m->height_data;
 158         roam_point_update_height(self->split);
 159
 160         /* Update normal */
 161         double pa[3];
 162         double pb[3];
 163         pa[0] = self->p.l->x - self->p.m->x;
 164         pa[1] = self->p.l->y - self->p.m->y;
 165         pa[2] = self->p.l->z - self->p.m->z;
 166
 167         pb[0] = self->p.r->x - self->p.m->x;
 168         pb[1] = self->p.r->y - self->p.m->y;
 169         pb[2] = self->p.r->z - self->p.m->z;
 170
 171         self->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 172         self->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 173         self->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 174
 175         double total = sqrt(self->norm[0] * self->norm[0] +
 176                             self->norm[1] * self->norm[1] +
 177                             self->norm[2] * self->norm[2]);
 178
 179         self->norm[0] /= total;
 180         self->norm[1] /= total;
 181         self->norm[2] /= total;
 182
 183         //g_message("roam_triangle_new: %p", self);
 184         return self;
 185 }
 186
 187 void roam_triangle_free(RoamTriangle *self)
 188 {
 189         g_free(self->split);
 190         g_free(self);
 191 }
 192
 193 void roam_triangle_add(RoamTriangle *self,
 194                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 195                 RoamSphere *sphere)
 196 {
 197         self->t.l = left;
 198         self->t.b = base;
 199         self->t.r = right;
 200
 201         roam_point_add_triangle(self->p.l, self);
 202         roam_point_add_triangle(self->p.m, self);
 203         roam_point_add_triangle(self->p.r, self);
 204
 205         if (sphere->view)
 206                 roam_triangle_update_errors(self, sphere);
 207
 208         self->handle = g_pqueue_push(sphere->triangles, self);
 209 }
 210
 211 void roam_triangle_remove(RoamTriangle *self, RoamSphere *sphere)
 212 {
 213         /* Update vertex normals */
 214         roam_point_remove_triangle(self->p.l, self);
 215         roam_point_remove_triangle(self->p.m, self);
 216         roam_point_remove_triangle(self->p.r, self);
 217
 218         g_pqueue_remove(sphere->triangles, self->handle);
 219 }
 220
 221 void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
 222 {
 223         if      (neigh->t.l == old) neigh->t.l = new;
 224         else if (neigh->t.b == old) neigh->t.b = new;
 225         else if (neigh->t.r == old) neigh->t.r = new;
 226         else g_assert_not_reached();
 227 }
 228
 229 gboolean roam_point_visible(RoamPoint *self, RoamSphere *sphere)
 230 {
 231         gint *view = sphere->view->view;
 232         return self->px > view[0] && self->px < view[2] &&
 233                self->py > view[1] && self->py < view[3] &&
 234                self->pz > 0       && self->pz < 1;
 235 }
 236 gboolean roam_triangle_visible(RoamTriangle *self, RoamSphere *sphere)
 237 {
 238         /* Do this with a bounding box */
 239         return roam_point_visible(self->p.l, sphere) ||
 240                roam_point_visible(self->p.m, sphere) ||
 241                roam_point_visible(self->p.r, sphere);
 242 }
 243
 244 void roam_triangle_update_errors(RoamTriangle *self, RoamSphere *sphere)
 245 {
 246         /* Update points */
 247         roam_point_update_projection(self->p.l, sphere);
 248         roam_point_update_projection(self->p.m, sphere);
 249         roam_point_update_projection(self->p.r, sphere);
 250
 251         /* Not exactly correct, could be out on both sides (middle in) */
 252         if (!roam_triangle_visible(self, sphere)) {
 253                 self->error = -1;
 254         } else {
 255                 roam_point_update_projection(self->split, sphere);
 256                 RoamPoint *l = self->p.l;
 257                 RoamPoint *m = self->p.m;
 258                 RoamPoint *r = self->p.r;
 259                 RoamPoint *split = self->split;
 260
 261                 /*               l-r midpoint        projected l-r midpoint */
 262                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 263                 gdouble pydist = (l->py + r->py)/2 - split->py;
 264
 265                 self->error = sqrt(pxdist*pxdist + pydist*pydist);
 266
 267                 /* Multiply by size of triangle */
 268                 double size = -( l->px * (m->py - r->py) +
 269                                  m->px * (r->py - l->py) +
 270                                  r->px * (l->py - m->py) ) / 2.0;
 271
 272                 /* Size < 0 == backface */
 273                 //if (size < 0)
 274                 //      self->error *= -1;
 275                 self->error *= size;
 276         }
 277 }
 278
 279 void roam_triangle_split(RoamTriangle *self, RoamSphere *sphere)
 280 {
 281         //g_message("roam_triangle_split: %p, e=%f\n", self, self->error);
 282
 283         sphere->polys += 2;
 284
 285         if (self != self->t.b->t.b)
 286                 roam_triangle_split(self->t.b, sphere);
 287
 288         RoamTriangle *base = self->t.b;
 289
 290         /* Add new triangles */
 291         RoamPoint *mid = self->split;
 292         RoamTriangle *sl = roam_triangle_new(self->p.m, mid, self->p.l); // Self Left
 293         RoamTriangle *sr = roam_triangle_new(self->p.r, mid, self->p.m); // Self Right
 294         RoamTriangle *bl = roam_triangle_new(base->p.m, mid, base->p.l); // Base Left
 295         RoamTriangle *br = roam_triangle_new(base->p.r, mid, base->p.m); // Base Right
 296
 297         /*                tri,l,  base,      r,  sphere */
 298         roam_triangle_add(sl, sr, self->t.l, br, sphere);
 299         roam_triangle_add(sr, bl, self->t.r, sl, sphere);
 300         roam_triangle_add(bl, br, base->t.l, sr, sphere);
 301         roam_triangle_add(br, sl, base->t.r, bl, sphere);
 302
 303         roam_triangle_sync_neighbors(sl, self, self->t.l);
 304         roam_triangle_sync_neighbors(sr, self, self->t.r);
 305         roam_triangle_sync_neighbors(bl, base, base->t.l);
 306         roam_triangle_sync_neighbors(br, base, base->t.r);
 307
 308         /* Remove old triangles */
 309         roam_triangle_remove(self, sphere);
 310         roam_triangle_remove(base, sphere);
 311
 312         /* Add/Remove diamonds */
 313         RoamDiamond *diamond = roam_diamond_new(self, base, sl, sr, bl, br);
 314         roam_diamond_update_errors(diamond, sphere);
 315         roam_diamond_add(diamond, sphere);
 316         roam_diamond_remove(self->parent, sphere);
 317         roam_diamond_remove(base->parent, sphere);
 318 }
 319
 320 void roam_triangle_draw(RoamTriangle *self)
 321 {
 322         glBegin(GL_TRIANGLES);
 323         glNormal3dv(self->p.r->norm); glVertex3dv((double*)self->p.r);
 324         glNormal3dv(self->p.m->norm); glVertex3dv((double*)self->p.m);
 325         glNormal3dv(self->p.l->norm); glVertex3dv((double*)self->p.l);
 326         glEnd();
 327         return;
 328 }
 329
 330 void roam_triangle_draw_normal(RoamTriangle *self)
 331 {
 332         double center[] = {
 333                 (self->p.l->x + self->p.m->x + self->p.r->x)/3.0,
 334                 (self->p.l->y + self->p.m->y + self->p.r->y)/3.0,
 335                 (self->p.l->z + self->p.m->z + self->p.r->z)/3.0,
 336         };
 337         double end[] = {
 338                 center[0]+self->norm[0]*2000000,
 339                 center[1]+self->norm[1]*2000000,
 340                 center[2]+self->norm[2]*2000000,
 341         };
 342         glBegin(GL_LINES);
 343         glVertex3dv(center);
 344         glVertex3dv(end);
 345         glEnd();
 346 }
 347
 348 /***************
 349  * RoamDiamond *
 350  ***************/
 351 RoamDiamond *roam_diamond_new(
 352                 RoamTriangle *parent0, RoamTriangle *parent1,
 353                 RoamTriangle *kid0, RoamTriangle *kid1,
 354                 RoamTriangle *kid2, RoamTriangle *kid3)
 355 {
 356         RoamDiamond *self = g_new0(RoamDiamond, 1);
 357
 358         self->kids[0] = kid0;
 359         self->kids[1] = kid1;
 360         self->kids[2] = kid2;
 361         self->kids[3] = kid3;
 362
 363         kid0->parent = self;
 364         kid1->parent = self;
 365         kid2->parent = self;
 366         kid3->parent = self;
 367
 368         self->parents[0] = parent0;
 369         self->parents[1] = parent1;
 370
 371         return self;
 372 }
 373 void roam_diamond_add(RoamDiamond *self, RoamSphere *sphere)
 374 {
 375         self->active = TRUE;
 376         self->error  = MAX(self->parents[0]->error, self->parents[1]->error);
 377         self->handle = g_pqueue_push(sphere->diamonds, self);
 378 }
 379 void roam_diamond_remove(RoamDiamond *self, RoamSphere *sphere)
 380 {
 381         if (self && self->active) {
 382                 self->active = FALSE;
 383                 g_pqueue_remove(sphere->diamonds, self->handle);
 384         }
 385 }
 386 void roam_diamond_merge(RoamDiamond *self, RoamSphere *sphere)
 387 {
 388         //g_message("roam_diamond_merge: %p, e=%f\n", self, self->error);
 389
 390         sphere->polys -= 2;
 391
 392         /* TODO: pick the best split */
 393         RoamTriangle **kids = self->kids;
 394
 395         /* Create triangles */
 396         RoamTriangle *tri  = self->parents[0];
 397         RoamTriangle *base = self->parents[1];
 398
 399         roam_triangle_add(tri,  kids[0]->t.b, base, kids[1]->t.b, sphere);
 400         roam_triangle_add(base, kids[2]->t.b, tri,  kids[3]->t.b, sphere);
 401
 402         roam_triangle_sync_neighbors(tri,  kids[0], kids[0]->t.b);
 403         roam_triangle_sync_neighbors(tri,  kids[1], kids[1]->t.b);
 404         roam_triangle_sync_neighbors(base, kids[2], kids[2]->t.b);
 405         roam_triangle_sync_neighbors(base, kids[3], kids[3]->t.b);
 406
 407         /* Remove triangles */
 408         roam_triangle_remove(kids[0], sphere);
 409         roam_triangle_remove(kids[1], sphere);
 410         roam_triangle_remove(kids[2], sphere);
 411         roam_triangle_remove(kids[3], sphere);
 412
 413         /* Add/Remove triangles */
 414         if (tri->t.l->t.l == tri->t.r->t.r &&
 415             tri->t.l->t.l != tri && tri->parent) {
 416                 roam_diamond_update_errors(tri->parent, sphere);
 417                 roam_diamond_add(tri->parent, sphere);
 418         }
 419
 420         if (base->t.l->t.l == base->t.r->t.r &&
 421             base->t.l->t.l != base && base->parent) {
 422                 roam_diamond_update_errors(base->parent, sphere);
 423                 roam_diamond_add(base->parent, sphere);
 424         }
 425
 426         /* Remove and free diamond and child triangles */
 427         roam_diamond_remove(self, sphere);
 428         g_assert(self->kids[0]->p.m == self->kids[1]->p.m &&
 429                  self->kids[1]->p.m == self->kids[2]->p.m &&
 430                  self->kids[2]->p.m == self->kids[3]->p.m);
 431         g_assert(self->kids[0]->p.m->tris == 0);
 432         roam_triangle_free(self->kids[0]);
 433         roam_triangle_free(self->kids[1]);
 434         roam_triangle_free(self->kids[2]);
 435         roam_triangle_free(self->kids[3]);
 436         g_free(self);
 437 }
 438 void roam_diamond_update_errors(RoamDiamond *self, RoamSphere *sphere)
 439 {
 440         roam_triangle_update_errors(self->parents[0], sphere);
 441         roam_triangle_update_errors(self->parents[1], sphere);
 442         self->error = MAX(self->parents[0]->error, self->parents[1]->error);
 443 }
 444
 445 /**************
 446  * RoamSphere *
 447  **************/
 448 RoamSphere *roam_sphere_new()
 449 {
 450         RoamSphere *self = g_new0(RoamSphere, 1);
 451         self->polys       = 8;
 452         self->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 453         self->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 454
 455         RoamPoint *vertexes[] = {
 456                 roam_point_new( 0, 1, 0), // 0
 457                 roam_point_new( 0,-1, 0), // 1
 458                 roam_point_new( 0, 0, 1), // 2
 459                 roam_point_new( 1, 0, 0), // 3
 460                 roam_point_new( 0, 0,-1), // 4
 461                 roam_point_new(-1, 0, 0), // 5
 462         };
 463         int _triangles[][2][3] = {
 464                 /*lv mv rv   ln, bn, rn */
 465                 {{2,0,3}, {3, 4, 1}}, // 0
 466                 {{3,0,4}, {0, 5, 2}}, // 1
 467                 {{4,0,5}, {1, 6, 3}}, // 2
 468                 {{5,0,2}, {2, 7, 0}}, // 3
 469                 {{3,1,2}, {5, 0, 7}}, // 4
 470                 {{4,1,3}, {6, 1, 4}}, // 5
 471                 {{5,1,4}, {7, 2, 5}}, // 6
 472                 {{2,1,5}, {4, 3, 6}}, // 7
 473         };
 474
 475         for (int i = 0; i < 6; i++)
 476                 roam_point_update_height(vertexes[i]);
 477         for (int i = 0; i < 8; i++)
 478                 self->roots[i] = roam_triangle_new(
 479                         vertexes[_triangles[i][0][0]],
 480                         vertexes[_triangles[i][0][1]],
 481                         vertexes[_triangles[i][0][2]]);
 482         for (int i = 0; i < 8; i++)
 483                 roam_triangle_add(self->roots[i],
 484                         self->roots[_triangles[i][1][0]],
 485                         self->roots[_triangles[i][1][1]],
 486                         self->roots[_triangles[i][1][2]],
 487                         self);
 488
 489         return self;
 490 }
 491 void roam_sphere_update_errors(RoamSphere *self)
 492 {
 493         g_debug("RoamSphere: update_errors - polys=%d", self->polys);
 494         if (!self->view)
 495                 self->view = roam_view_new();
 496         roam_view_update(self->view);
 497
 498         GPtrArray *tris = g_pqueue_get_array(self->triangles);
 499         GPtrArray *dias = g_pqueue_get_array(self->diamonds);
 500
 501         for (int i = 0; i < tris->len; i++) {
 502                 RoamTriangle *tri = tris->pdata[i];
 503                 roam_triangle_update_errors(tri, self);
 504                 g_pqueue_priority_changed(self->triangles, tri->handle);
 505         }
 506
 507         for (int i = 0; i < dias->len; i++) {
 508                 RoamDiamond *dia = dias->pdata[i];
 509                 roam_diamond_update_errors(dia, self);
 510                 g_pqueue_priority_changed(self->diamonds, dia->handle);
 511         }
 512
 513         g_ptr_array_free(tris, TRUE);
 514         g_ptr_array_free(dias, TRUE);
 515 }
 516
 517 void roam_sphere_split_one(RoamSphere *self)
 518 {
 519         RoamTriangle *to_split = g_pqueue_peek(self->triangles);
 520         if (!to_split) return;
 521         roam_triangle_split(to_split, self);
 522 }
 523 void roam_sphere_merge_one(RoamSphere *self)
 524 {
 525         RoamDiamond *to_merge = g_pqueue_peek(self->diamonds);
 526         if (!to_merge) return;
 527         roam_diamond_merge(to_merge, self);
 528 }
 529 gint roam_sphere_split_merge(RoamSphere *self)
 530 {
 531         gint iters = 0, max_iters = 500;
 532         //gint target = 4000;
 533         gint target = 2000;
 534         //gint target = 500;
 535
 536         if (!self->view)
 537                 return 0;
 538
 539         if (target - self->polys > 100) {
 540                 //g_debug("RoamSphere: split_merge - Splitting %d - %d > 100", target, self->polys);
 541                 while (self->polys < target && iters++ < max_iters)
 542                         roam_sphere_split_one(self);
 543         }
 544
 545         if (self->polys - target > 100) {
 546                 //g_debug("RoamSphere: split_merge - Merging %d - %d > 100", self->polys, target);
 547                 while (self->polys > target && iters++ < max_iters)
 548                         roam_sphere_merge_one(self);
 549         }
 550
 551         while (((RoamTriangle*)g_pqueue_peek(self->triangles))->error >
 552                ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error &&
 553                iters++ < max_iters) {
 554                 //g_debug("RoamSphere: split_merge - Fixing 1 %f > %f && %d < %d",
 555                 //              ((RoamTriangle*)g_pqueue_peek(self->triangles))->error,
 556                 //              ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error,
 557                 //              iters-1, max_iters);
 558                 roam_sphere_merge_one(self);
 559                 roam_sphere_split_one(self);
 560         }
 561
 562         return iters;
 563 }
 564 void roam_sphere_draw(RoamSphere *self)
 565 {
 566         g_debug("RoamSphere: draw");
 567         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw, NULL);
 568 }
 569 void roam_sphere_draw_normals(RoamSphere *self)
 570 {
 571         g_debug("RoamSphere: draw_normal");
 572         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 573 }
 574 void roam_sphere_free_tri(RoamTriangle *tri)
 575 {
 576         if (--tri->p.l->tris == 0) g_free(tri->p.l);
 577         if (--tri->p.m->tris == 0) g_free(tri->p.m);
 578         if (--tri->p.r->tris == 0) g_free(tri->p.r);
 579         roam_triangle_free(tri);
 580 }
 581 void roam_sphere_free(RoamSphere *self)
 582 {
 583         /* Slow method, but it should work */
 584         while (self->polys > 8)
 585                 roam_sphere_merge_one(self);
 586         /* TODO: free points */
 587         g_pqueue_foreach(self->triangles, (GFunc)roam_sphere_free_tri, NULL);
 588         g_pqueue_free(self->triangles);
 589         g_pqueue_free(self->diamonds);
 590         g_free(self->view);
 591         g_free(self);
 592 }