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