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 "roam.h"
  26
  27 /**
  28  * TODO:
  29  *   - Optimize for memory consumption
  30  *   - Profile for computation speed
  31  *   - Target polygon count/detail
  32  */
  33
  34 /* Misc */
  35 RoamView *roam_view_new()
  36 {
  37         return g_new0(RoamView, 1);
  38 }
  39 void roam_view_update(RoamView *view)
  40 {
  41         glGetDoublev (GL_MODELVIEW_MATRIX,  view->model);
  42         glGetDoublev (GL_PROJECTION_MATRIX, view->proj);
  43         glGetIntegerv(GL_VIEWPORT,          view->view);
  44         view->version++;
  45 }
  46
  47 /* For GPQueue comparators */
  48 static gint tri_cmp(RoamTriangle *a, RoamTriangle *b, gpointer data)
  49 {
  50         if      (a->error < b->error) return  1;
  51         else if (a->error > b->error) return -1;
  52         else                          return  0;
  53 }
  54 static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data)
  55 {
  56         if      (a->error < b->error) return -1;
  57         else if (a->error > b->error) return  1;
  58         else                          return  0;
  59 }
  60
  61 /*************
  62  * RoamPoint *
  63  *************/
  64 RoamPoint *roam_point_new(double x, double y, double z)
  65 {
  66         RoamPoint *self = g_new0(RoamPoint, 1);
  67         self->x = x;
  68         self->y = y;
  69         self->z = z;
  70         return self;
  71 }
  72 RoamPoint *roam_point_dup(RoamPoint *self)
  73 {
  74         RoamPoint *new = g_memdup(self, sizeof(RoamPoint));
  75         new->tris = 0;
  76         return new;
  77 }
  78 void roam_point_add_triangle(RoamPoint *self, RoamTriangle *triangle)
  79 {
  80         for (int i = 0; i < 3; i++) {
  81                 self->norm[i] *= self->tris;
  82                 self->norm[i] += triangle->norm[i];
  83         }
  84         self->tris++;
  85         for (int i = 0; i < 3; i++)
  86                 self->norm[i] /= self->tris;
  87 }
  88 void roam_point_remove_triangle(RoamPoint *self, RoamTriangle *triangle)
  89 {
  90         for (int i = 0; i < 3; i++) {
  91                 self->norm[i] *= self->tris;
  92                 self->norm[i] -= triangle->norm[i];
  93         }
  94         self->tris--;
  95         if (self->tris)
  96                 for (int i = 0; i < 3; i++)
  97                         self->norm[i] /= self->tris;
  98 }
  99 void roam_point_update_height(RoamPoint *self, RoamSphere *sphere)
 100 {
 101         if (sphere->height_func) {
 102                 sphere->height_func(self, sphere->user_data);
 103         } else {
 104                 gdouble dist = sqrt(self->x * self->x +
 105                                     self->y * self->y +
 106                                     self->z * self->z);
 107                 self->x = self->x/dist * 6371000;
 108                 self->y = self->y/dist * 6371000;
 109                 self->z = self->z/dist * 6371000;
 110         }
 111 }
 112 void roam_point_update_projection(RoamPoint *self, RoamSphere *sphere)
 113 {
 114         static int count   = 0;
 115         static int version = 0;
 116         if (version != sphere->view->version) {
 117                 g_debug("Projected %d points", count);
 118                 count   = 0;
 119                 version = sphere->view->version;
 120         }
 121
 122         if (self->pversion != sphere->view->version) {
 123                 /* Cache projection */
 124                 gluProject(self->x, self->y, self->z,
 125                         sphere->view->model, sphere->view->proj, sphere->view->view,
 126                         &self->px, &self->py, &self->pz);
 127                 self->pversion = sphere->view->version;
 128                 count++;
 129         }
 130 }
 131
 132 /****************
 133  * RoamTriangle *
 134  ****************/
 135 RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
 136 {
 137         RoamTriangle *self = g_new0(RoamTriangle, 1);
 138
 139         self->p.l = l;
 140         self->p.m = m;
 141         self->p.r = r;
 142         self->split = roam_point_new(
 143                 (l->x + r->x)/2,
 144                 (l->y + r->y)/2,
 145                 (l->z + r->z)/2);
 146
 147         self->error = 0;
 148
 149         /* Update normal */
 150         double pa[3];
 151         double pb[3];
 152         pa[0] = self->p.l->x - self->p.m->x;
 153         pa[1] = self->p.l->y - self->p.m->y;
 154         pa[2] = self->p.l->z - self->p.m->z;
 155
 156         pb[0] = self->p.r->x - self->p.m->x;
 157         pb[1] = self->p.r->y - self->p.m->y;
 158         pb[2] = self->p.r->z - self->p.m->z;
 159
 160         self->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
 161         self->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
 162         self->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
 163
 164         double total = sqrt(self->norm[0] * self->norm[0] +
 165                             self->norm[1] * self->norm[1] +
 166                             self->norm[2] * self->norm[2]);
 167
 168         self->norm[0] /= total;
 169         self->norm[1] /= total;
 170         self->norm[2] /= total;
 171
 172         //g_message("roam_triangle_new: %p", self);
 173         return self;
 174 }
 175
 176 void roam_triangle_free(RoamTriangle *self)
 177 {
 178         g_free(self->split);
 179         g_free(self);
 180 }
 181
 182 void roam_triangle_add(RoamTriangle *self,
 183                 RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
 184                 RoamSphere *sphere)
 185 {
 186         self->t.l = left;
 187         self->t.b = base;
 188         self->t.r = right;
 189
 190         roam_point_add_triangle(self->p.l, self);
 191         roam_point_add_triangle(self->p.m, self);
 192         roam_point_add_triangle(self->p.r, self);
 193
 194         if (sphere->view)
 195                 roam_triangle_update_errors(self, sphere);
 196
 197         self->handle = g_pqueue_push(sphere->triangles, self);
 198 }
 199
 200 void roam_triangle_remove(RoamTriangle *self, RoamSphere *sphere)
 201 {
 202         /* Update vertex normals */
 203         roam_point_remove_triangle(self->p.l, self);
 204         roam_point_remove_triangle(self->p.m, self);
 205         roam_point_remove_triangle(self->p.r, self);
 206
 207         g_pqueue_remove(sphere->triangles, self->handle);
 208 }
 209
 210 void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
 211 {
 212         if      (neigh->t.l == old) neigh->t.l = new;
 213         else if (neigh->t.b == old) neigh->t.b = new;
 214         else if (neigh->t.r == old) neigh->t.r = new;
 215         else g_assert_not_reached();
 216 }
 217
 218 gboolean roam_point_visible(RoamPoint *self, RoamSphere *sphere)
 219 {
 220         gint *view = sphere->view->view;
 221         return self->px > view[0] && self->px < view[2] &&
 222                self->py > view[1] && self->py < view[3] &&
 223                self->pz > 0       && self->pz < 1;
 224         //double x, y, z;
 225         //int view[4] = {0,0,1,1};
 226         //gluProject(self->x, self->y, self->z,
 227         //              sphere->view->model, sphere->view->proj, view,
 228         //              &x, &y, &z);
 229         //return !(x < 0 || x > 1 ||
 230         //         y < 0 || y > 1 ||
 231         //         z < 0 || z > 1);
 232 }
 233 gboolean roam_triangle_visible(RoamTriangle *self, RoamSphere *sphere)
 234 {
 235         /* Do this with a bounding box */
 236         return roam_point_visible(self->p.l, sphere) ||
 237                roam_point_visible(self->p.m, sphere) ||
 238                roam_point_visible(self->p.r, sphere);
 239 }
 240
 241 void roam_triangle_update_errors(RoamTriangle *self, RoamSphere *sphere)
 242 {
 243         /* Update points */
 244         roam_point_update_projection(self->p.l, sphere);
 245         roam_point_update_projection(self->p.m, sphere);
 246         roam_point_update_projection(self->p.r, sphere);
 247         roam_point_update_projection(self->split, sphere);
 248
 249         /* Not exactly correct, could be out on both sides (middle in) */
 250         if (!roam_triangle_visible(self, sphere)) {
 251                 self->error = -1;
 252         } else {
 253                 RoamPoint *l = self->p.l;
 254                 RoamPoint *m = self->p.m;
 255                 RoamPoint *r = self->p.r;
 256                 RoamPoint *split = self->split;
 257
 258                 /*               l-r midpoint        projected l-r midpoint */
 259                 gdouble pxdist = (l->px + r->px)/2 - split->px;
 260                 gdouble pydist = (l->py + r->py)/2 - split->py;
 261
 262                 self->error = sqrt(pxdist*pxdist + pydist*pydist);
 263
 264                 /* Multiply by size of triangle */
 265                 double size = -( l->px * (m->py - r->py) +
 266                                  m->px * (r->py - l->py) +
 267                                  r->px * (l->py - m->py) ) / 2.0;
 268
 269                 /* Size < 0 == backface */
 270                 self->error *= size;
 271         }
 272 }
 273
 274 void roam_triangle_split(RoamTriangle *self, RoamSphere *sphere)
 275 {
 276         //g_message("roam_triangle_split: %p, e=%f\n", self, self->error);
 277
 278         sphere->polys += 2;
 279
 280         if (self != self->t.b->t.b)
 281                 roam_triangle_split(self->t.b, sphere);
 282
 283         RoamTriangle *base = self->t.b;
 284
 285
 286         /* Add new triangles */
 287         RoamPoint *mid = self->split;
 288         RoamTriangle *sl = roam_triangle_new(self->p.m, mid, self->p.l); // Self Left
 289         RoamTriangle *sr = roam_triangle_new(self->p.r, mid, self->p.m); // Self Right
 290         RoamTriangle *bl = roam_triangle_new(base->p.m, mid, base->p.l); // Base Left
 291         RoamTriangle *br = roam_triangle_new(base->p.r, mid, base->p.m); // Base Right
 292
 293         roam_point_update_height(sl->split, sphere);
 294         roam_point_update_height(sr->split, sphere);
 295         roam_point_update_height(bl->split, sphere);
 296         roam_point_update_height(br->split, sphere);
 297
 298         /*                tri,l,  base,      r,  sphere */
 299         roam_triangle_add(sl, sr, self->t.l, br, sphere);
 300         roam_triangle_add(sr, bl, self->t.r, sl, sphere);
 301         roam_triangle_add(bl, br, base->t.l, sr, sphere);
 302         roam_triangle_add(br, sl, base->t.r, bl, sphere);
 303
 304         roam_triangle_sync_neighbors(sl, self, self->t.l);
 305         roam_triangle_sync_neighbors(sr, self, self->t.r);
 306         roam_triangle_sync_neighbors(bl, base, base->t.l);
 307         roam_triangle_sync_neighbors(br, base, base->t.r);
 308
 309         /* Remove old triangles */
 310         roam_triangle_remove(self, sphere);
 311         roam_triangle_remove(base, sphere);
 312
 313         /* Add/Remove diamonds */
 314         RoamDiamond *diamond = roam_diamond_new(self, base, sl, sr, bl, br);
 315         roam_diamond_update_errors(diamond, sphere);
 316         roam_diamond_add(diamond, sphere);
 317         roam_diamond_remove(self->parent, sphere);
 318         roam_diamond_remove(base->parent, sphere);
 319 }
 320
 321 void roam_triangle_draw(RoamTriangle *self)
 322 {
 323         glBegin(GL_TRIANGLES);
 324         glNormal3dv(self->p.r->norm); glVertex3dv((double*)self->p.r);
 325         glNormal3dv(self->p.m->norm); glVertex3dv((double*)self->p.m);
 326         glNormal3dv(self->p.l->norm); glVertex3dv((double*)self->p.l);
 327         glEnd();
 328         return;
 329 }
 330
 331 void roam_triangle_draw_normal(RoamTriangle *self)
 332 {
 333         double center[] = {
 334                 (self->p.l->x + self->p.m->x + self->p.r->x)/3.0,
 335                 (self->p.l->y + self->p.m->y + self->p.r->y)/3.0,
 336                 (self->p.l->z + self->p.m->z + self->p.r->z)/3.0,
 337         };
 338         double end[] = {
 339                 center[0]+self->norm[0]*2000000,
 340                 center[1]+self->norm[1]*2000000,
 341                 center[2]+self->norm[2]*2000000,
 342         };
 343         glBegin(GL_LINES);
 344         glVertex3dv(center);
 345         glVertex3dv(end);
 346         glEnd();
 347 }
 348
 349 /***************
 350  * RoamDiamond *
 351  ***************/
 352 RoamDiamond *roam_diamond_new(
 353                 RoamTriangle *parent0, RoamTriangle *parent1,
 354                 RoamTriangle *kid0, RoamTriangle *kid1,
 355                 RoamTriangle *kid2, RoamTriangle *kid3)
 356 {
 357         RoamDiamond *self = g_new0(RoamDiamond, 1);
 358
 359         self->kids[0] = kid0;
 360         self->kids[1] = kid1;
 361         self->kids[2] = kid2;
 362         self->kids[3] = kid3;
 363
 364         kid0->parent = self;
 365         kid1->parent = self;
 366         kid2->parent = self;
 367         kid3->parent = self;
 368
 369         self->parents[0] = parent0;
 370         self->parents[1] = parent1;
 371
 372         return self;
 373 }
 374 void roam_diamond_add(RoamDiamond *self, RoamSphere *sphere)
 375 {
 376         self->active = TRUE;
 377         self->error  = MAX(self->parents[0]->error, self->parents[1]->error);
 378         self->handle = g_pqueue_push(sphere->diamonds, self);
 379 }
 380 void roam_diamond_remove(RoamDiamond *self, RoamSphere *sphere)
 381 {
 382         if (self && self->active) {
 383                 self->active = FALSE;
 384                 g_pqueue_remove(sphere->diamonds, self->handle);
 385         }
 386 }
 387 void roam_diamond_merge(RoamDiamond *self, RoamSphere *sphere)
 388 {
 389         //g_message("roam_diamond_merge: %p, e=%f\n", self, self->error);
 390
 391         sphere->polys -= 2;
 392
 393         /* TODO: pick the best split */
 394         RoamTriangle **kids = self->kids;
 395
 396         /* Create triangles */
 397         RoamTriangle *tri  = self->parents[0];
 398         RoamTriangle *base = self->parents[1];
 399
 400         roam_triangle_add(tri,  kids[0]->t.b, base, kids[1]->t.b, sphere);
 401         roam_triangle_add(base, kids[2]->t.b, tri,  kids[3]->t.b, sphere);
 402
 403         roam_triangle_sync_neighbors(tri,  kids[0], kids[0]->t.b);
 404         roam_triangle_sync_neighbors(tri,  kids[1], kids[1]->t.b);
 405         roam_triangle_sync_neighbors(base, kids[2], kids[2]->t.b);
 406         roam_triangle_sync_neighbors(base, kids[3], kids[3]->t.b);
 407
 408         /* Remove triangles */
 409         roam_triangle_remove(kids[0], sphere);
 410         roam_triangle_remove(kids[1], sphere);
 411         roam_triangle_remove(kids[2], sphere);
 412         roam_triangle_remove(kids[3], sphere);
 413
 414         /* Add/Remove triangles */
 415         if (tri->t.l->t.l == tri->t.r->t.r &&
 416             tri->t.l->t.l != tri && tri->parent) {
 417                 roam_diamond_update_errors(tri->parent, sphere);
 418                 roam_diamond_add(tri->parent, sphere);
 419         }
 420
 421         if (base->t.l->t.l == base->t.r->t.r &&
 422             base->t.l->t.l != base && base->parent) {
 423                 roam_diamond_update_errors(base->parent, sphere);
 424                 roam_diamond_add(base->parent, sphere);
 425         }
 426
 427         /* Remove and free diamond and child triangles */
 428         roam_diamond_remove(self, sphere);
 429         g_assert(self->kids[0]->p.m == self->kids[1]->p.m &&
 430                  self->kids[1]->p.m == self->kids[2]->p.m &&
 431                  self->kids[2]->p.m == self->kids[3]->p.m);
 432         g_assert(self->kids[0]->p.m->tris == 0);
 433         roam_triangle_free(self->kids[0]);
 434         roam_triangle_free(self->kids[1]);
 435         roam_triangle_free(self->kids[2]);
 436         roam_triangle_free(self->kids[3]);
 437         g_free(self);
 438 }
 439 void roam_diamond_update_errors(RoamDiamond *self, RoamSphere *sphere)
 440 {
 441         roam_triangle_update_errors(self->parents[0], sphere);
 442         roam_triangle_update_errors(self->parents[1], sphere);
 443         self->error = MAX(self->parents[0]->error, self->parents[1]->error);
 444 }
 445
 446 /**************
 447  * RoamSphere *
 448  **************/
 449 RoamSphere *roam_sphere_new(gpointer user_data)
 450 {
 451         RoamSphere *self = g_new0(RoamSphere, 1);
 452         self->user_data   = user_data;
 453         self->polys       = 12;
 454         self->triangles   = g_pqueue_new((GCompareDataFunc)tri_cmp, NULL);
 455         self->diamonds    = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL);
 456
 457         RoamPoint *vertexes[] = {
 458                 roam_point_new( 1, 1, 1), // 0
 459                 roam_point_new( 1, 1,-1), // 1
 460                 roam_point_new( 1,-1, 1), // 2
 461                 roam_point_new( 1,-1,-1), // 3
 462                 roam_point_new(-1, 1, 1), // 4
 463                 roam_point_new(-1, 1,-1), // 5
 464                 roam_point_new(-1,-1, 1), // 6
 465                 roam_point_new(-1,-1,-1), // 7
 466         };
 467         int _triangles[][2][3] = {
 468                 /*lv mv rv   ln, bn, rn */
 469                 {{3,2,0}, {10, 1, 7}}, // 0
 470                 {{0,1,3}, { 9, 0, 2}}, // 1
 471                 {{7,3,1}, {11, 3, 1}}, // 2
 472                 {{1,5,7}, { 8, 2, 4}}, // 3
 473                 {{6,7,5}, {11, 5, 3}}, // 4
 474                 {{5,4,6}, { 8, 4, 6}}, // 5
 475                 {{2,6,4}, {10, 7, 5}}, // 6
 476                 {{4,0,2}, { 9, 6, 0}}, // 7
 477                 {{4,5,1}, { 5, 9, 3}}, // 8
 478                 {{1,0,4}, { 1, 8, 7}}, // 9
 479                 {{6,2,3}, { 6,11, 0}}, // 10
 480                 {{3,7,6}, { 2,10, 4}}, // 11
 481         };
 482         RoamTriangle *triangles[12];
 483
 484         for (int i = 0; i < 8; i++)
 485                 roam_point_update_height(vertexes[i], self);
 486         for (int i = 0; i < 12; i++)
 487                 triangles[i] = roam_triangle_new(
 488                         vertexes[_triangles[i][0][0]],
 489                         vertexes[_triangles[i][0][1]],
 490                         vertexes[_triangles[i][0][2]]);
 491         for (int i = 0; i < 12; i++)
 492                 roam_point_update_height(triangles[i]->split, self);
 493         for (int i = 0; i < 12; i++)
 494                 roam_triangle_add(triangles[i],
 495                         triangles[_triangles[i][1][0]],
 496                         triangles[_triangles[i][1][1]],
 497                         triangles[_triangles[i][1][2]],
 498                         self);
 499
 500         return self;
 501 }
 502 void roam_sphere_update_errors(RoamSphere *self)
 503 {
 504         g_debug("RoamSphere: update - polys=%d", self->polys);
 505         if (!self->view)
 506                 self->view = roam_view_new();
 507         roam_view_update(self->view);
 508
 509         GPtrArray *tris = g_pqueue_get_array(self->triangles);
 510         GPtrArray *dias = g_pqueue_get_array(self->diamonds);
 511
 512         for (int i = 0; i < tris->len; i++) {
 513                 RoamTriangle *tri = tris->pdata[i];
 514                 roam_triangle_update_errors(tri, self);
 515                 g_pqueue_priority_changed(self->triangles, tri->handle);
 516         }
 517
 518         for (int i = 0; i < dias->len; i++) {
 519                 RoamDiamond *dia = dias->pdata[i];
 520                 roam_diamond_update_errors(dia, self);
 521                 g_pqueue_priority_changed(self->diamonds, dia->handle);
 522         }
 523
 524         g_ptr_array_free(tris, TRUE);
 525         g_ptr_array_free(dias, TRUE);
 526 }
 527
 528 void roam_sphere_split_one(RoamSphere *self)
 529 {
 530         RoamTriangle *to_split = g_pqueue_peek(self->triangles);
 531         if (!to_split) return;
 532         roam_triangle_split(to_split, self);
 533 }
 534 void roam_sphere_merge_one(RoamSphere *self)
 535 {
 536         RoamDiamond *to_merge = g_pqueue_peek(self->diamonds);
 537         if (!to_merge) return;
 538         roam_diamond_merge(to_merge, self);
 539 }
 540 gint roam_sphere_split_merge(RoamSphere *self)
 541 {
 542         gint iters = 0, max_iters = 500;
 543         gint target = 4000;
 544
 545         if (!self->view)
 546                 return 0;
 547
 548         if (target - self->polys > 100)
 549                 while (self->polys < target && iters++ < max_iters)
 550                         roam_sphere_split_one(self);
 551
 552         if (self->polys - target > 100)
 553                 while (self->polys > target && iters++ < max_iters)
 554                         roam_sphere_merge_one(self);
 555
 556         while (((RoamTriangle*)g_pqueue_peek(self->triangles))->error >
 557                ((RoamDiamond *)g_pqueue_peek(self->diamonds ))->error &&
 558                iters++ < max_iters) {
 559                 roam_sphere_merge_one(self);
 560                 roam_sphere_split_one(self);
 561         }
 562
 563         return iters;
 564 }
 565 void roam_sphere_draw(RoamSphere *self)
 566 {
 567         g_message("RoamSphere: draw");
 568         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw, NULL);
 569 }
 570 void roam_sphere_draw_normals(RoamSphere *self)
 571 {
 572         g_message("RoamSphere: draw_normal");
 573         g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw_normal, NULL);
 574 }
 575 void roam_sphere_free_tri(RoamTriangle *tri)
 576 {
 577         if (--tri->p.l->tris == 0) g_free(tri->p.l);
 578         if (--tri->p.m->tris == 0) g_free(tri->p.m);
 579         if (--tri->p.r->tris == 0) g_free(tri->p.r);
 580         roam_triangle_free(tri);
 581 }
 582 void roam_sphere_free(RoamSphere *self)
 583 {
 584         /* Slow method, but it should work */
 585         while (self->polys > 12)
 586                 roam_sphere_merge_one(self);
 587         /* TODO: free points */
 588         g_pqueue_foreach(self->triangles, (GFunc)roam_sphere_free_tri, NULL);
 589         g_pqueue_free(self->triangles);
 590         g_pqueue_free(self->diamonds);
 591         g_free(self);
 592 }