tools/quake3/common/polylib.c

   1 /*
   2 Copyright (C) 1999-2007 id Software, Inc. and contributors.
   3 For a list of contributors, see the accompanying CONTRIBUTORS file.
   4
   5 This file is part of GtkRadiant.
   6
   7 GtkRadiant is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 GtkRadiant is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GtkRadiant; if not, write to the Free Software
  19 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20 */
  21
  22
  23 #include "cmdlib.h"
  24 #include "mathlib.h"
  25 #include "inout.h"
  26 #include "polylib.h"
  27 #include "qfiles.h"
  28
  29
  30 extern int numthreads;
  31
  32 // counters are only bumped when running single threaded,
  33 // because they are an awefull coherence problem
  34 int     c_active_windings;
  35 int     c_peak_windings;
  36 int     c_winding_allocs;
  37 int     c_winding_points;
  38
  39 #define BOGUS_RANGE     WORLD_SIZE
  40
  41 void pw(winding_t *w)
  42 {
  43         int             i;
  44         for (i=0 ; i<w->numpoints ; i++)
  45                 Sys_Printf ("(%5.1f, %5.1f, %5.1f)\n",w->p[i][0], w->p[i][1],w->p[i][2]);
  46 }
  47
  48
  49 /*
  50 =============
  51 AllocWinding
  52 =============
  53 */
  54 winding_t       *AllocWinding (int points)
  55 {
  56         winding_t       *w;
  57         int                     s;
  58
  59   if (points >= MAX_POINTS_ON_WINDING)
  60     Error ("AllocWinding failed: MAX_POINTS_ON_WINDING exceeded");
  61
  62         if (numthreads == 1)
  63         {
  64                 c_winding_allocs++;
  65                 c_winding_points += points;
  66                 c_active_windings++;
  67                 if (c_active_windings > c_peak_windings)
  68                         c_peak_windings = c_active_windings;
  69         }
  70         s = sizeof(vec_t)*3*points + sizeof(int);
  71         w = safe_malloc (s);
  72         memset (w, 0, s);
  73         return w;
  74 }
  75
  76 void FreeWinding (winding_t *w)
  77 {
  78         if (*(unsigned *)w == 0xdeaddead)
  79                 Error ("FreeWinding: freed a freed winding");
  80         *(unsigned *)w = 0xdeaddead;
  81
  82         if (numthreads == 1)
  83                 c_active_windings--;
  84         free (w);
  85 }
  86
  87 /*
  88 ============
  89 RemoveColinearPoints
  90 ============
  91 */
  92 int     c_removed;
  93
  94 void    RemoveColinearPoints (winding_t *w)
  95 {
  96         int             i, j, k;
  97         vec3_t  v1, v2;
  98         int             nump;
  99         vec3_t  p[MAX_POINTS_ON_WINDING];
 100
 101         nump = 0;
 102         for (i=0 ; i<w->numpoints ; i++)
 103         {
 104                 j = (i+1)%w->numpoints;
 105                 k = (i+w->numpoints-1)%w->numpoints;
 106                 VectorSubtract (w->p[j], w->p[i], v1);
 107                 VectorSubtract (w->p[i], w->p[k], v2);
 108                 VectorNormalize(v1,v1);
 109                 VectorNormalize(v2,v2);
 110                 if (DotProduct(v1, v2) < 0.999)
 111                 {
 112                         VectorCopy (w->p[i], p[nump]);
 113                         nump++;
 114                 }
 115         }
 116
 117         if (nump == w->numpoints)
 118                 return;
 119
 120         if (numthreads == 1)
 121                 c_removed += w->numpoints - nump;
 122         w->numpoints = nump;
 123         memcpy (w->p, p, nump*sizeof(p[0]));
 124 }
 125
 126 /*
 127 ============
 128 WindingPlane
 129 ============
 130 */
 131 void WindingPlane (winding_t *w, vec3_t normal, vec_t *dist)
 132 {
 133         vec3_t  v1, v2;
 134
 135         VectorSubtract (w->p[1], w->p[0], v1);
 136         VectorSubtract (w->p[2], w->p[0], v2);
 137         CrossProduct (v2, v1, normal);
 138         VectorNormalize (normal, normal);
 139         *dist = DotProduct (w->p[0], normal);
 140
 141 }
 142
 143 /*
 144 =============
 145 WindingArea
 146 =============
 147 */
 148 vec_t   WindingArea (winding_t *w)
 149 {
 150         int             i;
 151         vec3_t  d1, d2, cross;
 152         vec_t   total;
 153
 154         total = 0;
 155         for (i=2 ; i<w->numpoints ; i++)
 156         {
 157                 VectorSubtract (w->p[i-1], w->p[0], d1);
 158                 VectorSubtract (w->p[i], w->p[0], d2);
 159                 CrossProduct (d1, d2, cross);
 160                 total += 0.5 * VectorLength ( cross );
 161         }
 162         return total;
 163 }
 164
 165 void    WindingBounds (winding_t *w, vec3_t mins, vec3_t maxs)
 166 {
 167         vec_t   v;
 168         int             i,j;
 169
 170         mins[0] = mins[1] = mins[2] = 99999;
 171         maxs[0] = maxs[1] = maxs[2] = -99999;
 172
 173         for (i=0 ; i<w->numpoints ; i++)
 174         {
 175                 for (j=0 ; j<3 ; j++)
 176                 {
 177                         v = w->p[i][j];
 178                         if (v < mins[j])
 179                                 mins[j] = v;
 180                         if (v > maxs[j])
 181                                 maxs[j] = v;
 182                 }
 183         }
 184 }
 185
 186 /*
 187 =============
 188 WindingCenter
 189 =============
 190 */
 191 void    WindingCenter (winding_t *w, vec3_t center)
 192 {
 193         int             i;
 194         float   scale;
 195
 196         VectorCopy (vec3_origin, center);
 197         for (i=0 ; i<w->numpoints ; i++)
 198                 VectorAdd (w->p[i], center, center);
 199
 200         scale = 1.0/w->numpoints;
 201         VectorScale (center, scale, center);
 202 }
 203
 204 /*
 205 =================
 206 BaseWindingForPlane
 207 =================
 208 */
 209 winding_t *BaseWindingForPlane (vec3_t normal, vec_t dist)
 210 {
 211         int             i, x;
 212         vec_t   max, v;
 213         vec3_t  org, vright, vup;
 214         winding_t       *w;
 215
 216 // find the major axis
 217
 218         max = -BOGUS_RANGE;
 219         x = -1;
 220         for (i=0 ; i<3; i++)
 221         {
 222                 v = fabs(normal[i]);
 223                 if (v > max)
 224                 {
 225                         x = i;
 226                         max = v;
 227                 }
 228         }
 229         if (x==-1)
 230                 Error ("BaseWindingForPlane: no axis found");
 231
 232         VectorCopy (vec3_origin, vup);
 233         switch (x)
 234         {
 235         case 0:
 236         case 1:
 237                 vup[2] = 1;
 238                 break;
 239         case 2:
 240                 vup[0] = 1;
 241                 break;
 242         }
 243
 244         v = DotProduct (vup, normal);
 245         VectorMA (vup, -v, normal, vup);
 246         VectorNormalize (vup, vup);
 247
 248         VectorScale (normal, dist, org);
 249
 250         CrossProduct (vup, normal, vright);
 251
 252         VectorScale (vup, MAX_WORLD_COORD, vup);
 253         VectorScale (vright, MAX_WORLD_COORD, vright);
 254
 255   // project a really big       axis aligned box onto the plane
 256         w = AllocWinding (4);
 257
 258         VectorSubtract (org, vright, w->p[0]);
 259         VectorAdd (w->p[0], vup, w->p[0]);
 260
 261         VectorAdd (org, vright, w->p[1]);
 262         VectorAdd (w->p[1], vup, w->p[1]);
 263
 264         VectorAdd (org, vright, w->p[2]);
 265         VectorSubtract (w->p[2], vup, w->p[2]);
 266
 267         VectorSubtract (org, vright, w->p[3]);
 268         VectorSubtract (w->p[3], vup, w->p[3]);
 269
 270         w->numpoints = 4;
 271
 272         return w;
 273 }
 274
 275 /*
 276 ==================
 277 CopyWinding
 278 ==================
 279 */
 280 winding_t       *CopyWinding (winding_t *w)
 281 {
 282         int                     size;
 283         winding_t       *c;
 284
 285         c = AllocWinding (w->numpoints);
 286         size = (int)((winding_t *)0)->p[w->numpoints];
 287         memcpy (c, w, size);
 288         return c;
 289 }
 290
 291 /*
 292 ==================
 293 ReverseWinding
 294 ==================
 295 */
 296 winding_t       *ReverseWinding (winding_t *w)
 297 {
 298         int                     i;
 299         winding_t       *c;
 300
 301         c = AllocWinding (w->numpoints);
 302         for (i=0 ; i<w->numpoints ; i++)
 303         {
 304                 VectorCopy (w->p[w->numpoints-1-i], c->p[i]);
 305         }
 306         c->numpoints = w->numpoints;
 307         return c;
 308 }
 309
 310
 311 /*
 312 =============
 313 ClipWindingEpsilon
 314 =============
 315 */
 316 void    ClipWindingEpsilon (winding_t *in, vec3_t normal, vec_t dist,
 317                                 vec_t epsilon, winding_t **front, winding_t **back)
 318 {
 319         vec_t   dists[MAX_POINTS_ON_WINDING+4];
 320         int             sides[MAX_POINTS_ON_WINDING+4];
 321         int             counts[3];
 322         static  vec_t   dot;            // VC 4.2 optimizer bug if not static
 323         int             i, j;
 324         vec_t   *p1, *p2;
 325         vec3_t  mid;
 326         winding_t       *f, *b;
 327         int             maxpts;
 328
 329         counts[0] = counts[1] = counts[2] = 0;
 330
 331 // determine sides for each point
 332         for (i=0 ; i<in->numpoints ; i++)
 333   {
 334
 335                 dot = DotProduct (in->p[i], normal);
 336                 dot -= dist;
 337                 dists[i] = dot;
 338                 if (dot > epsilon)
 339                         sides[i] = SIDE_FRONT;
 340                 else if (dot < -epsilon)
 341                         sides[i] = SIDE_BACK;
 342                 else
 343                 {
 344                         sides[i] = SIDE_ON;
 345                 }
 346                 counts[sides[i]]++;
 347         }
 348         sides[i] = sides[0];
 349         dists[i] = dists[0];
 350
 351         *front = *back = NULL;
 352
 353         if (!counts[0])
 354         {
 355                 *back = CopyWinding (in);
 356                 return;
 357         }
 358         if (!counts[1])
 359         {
 360                 *front = CopyWinding (in);
 361                 return;
 362         }
 363
 364         maxpts = in->numpoints+4;       // cant use counts[0]+2 because
 365                                                                 // of fp grouping errors
 366
 367         *front = f = AllocWinding (maxpts);
 368         *back = b = AllocWinding (maxpts);
 369
 370         for (i=0 ; i<in->numpoints ; i++)
 371         {
 372                 p1 = in->p[i];
 373
 374                 if (sides[i] == SIDE_ON)
 375                 {
 376                         VectorCopy (p1, f->p[f->numpoints]);
 377                         f->numpoints++;
 378                         VectorCopy (p1, b->p[b->numpoints]);
 379                         b->numpoints++;
 380                         continue;
 381                 }
 382
 383                 if (sides[i] == SIDE_FRONT)
 384                 {
 385                         VectorCopy (p1, f->p[f->numpoints]);
 386                         f->numpoints++;
 387                 }
 388                 if (sides[i] == SIDE_BACK)
 389                 {
 390                         VectorCopy (p1, b->p[b->numpoints]);
 391                         b->numpoints++;
 392                 }
 393
 394                 if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
 395                         continue;
 396
 397         // generate a split point
 398                 p2 = in->p[(i+1)%in->numpoints];
 399
 400                 dot = dists[i] / (dists[i]-dists[i+1]);
 401                 for (j=0 ; j<3 ; j++)
 402                 {       // avoid round off error when possible
 403                         if (normal[j] == 1)
 404                                 mid[j] = dist;
 405                         else if (normal[j] == -1)
 406                                 mid[j] = -dist;
 407                         else
 408                                 mid[j] = p1[j] + dot*(p2[j]-p1[j]);
 409                 }
 410
 411                 VectorCopy (mid, f->p[f->numpoints]);
 412                 f->numpoints++;
 413                 VectorCopy (mid, b->p[b->numpoints]);
 414                 b->numpoints++;
 415         }
 416
 417         if (f->numpoints > maxpts || b->numpoints > maxpts)
 418                 Error ("ClipWinding: points exceeded estimate");
 419         if (f->numpoints > MAX_POINTS_ON_WINDING || b->numpoints > MAX_POINTS_ON_WINDING)
 420                 Error ("ClipWinding: MAX_POINTS_ON_WINDING");
 421 }
 422
 423
 424 /*
 425 =============
 426 ChopWindingInPlace
 427 =============
 428 */
 429 void ChopWindingInPlace (winding_t **inout, vec3_t normal, vec_t dist, vec_t epsilon)
 430 {
 431         winding_t       *in;
 432         vec_t   dists[MAX_POINTS_ON_WINDING+4];
 433         int             sides[MAX_POINTS_ON_WINDING+4];
 434         int             counts[3];
 435         static  vec_t   dot;            // VC 4.2 optimizer bug if not static
 436         int             i, j;
 437         vec_t   *p1, *p2;
 438         vec3_t  mid;
 439         winding_t       *f;
 440         int             maxpts;
 441
 442         in = *inout;
 443         counts[0] = counts[1] = counts[2] = 0;
 444
 445 // determine sides for each point
 446         for (i=0 ; i<in->numpoints ; i++)
 447         {
 448                 dot = DotProduct (in->p[i], normal);
 449                 dot -= dist;
 450                 dists[i] = dot;
 451                 if (dot > epsilon)
 452                         sides[i] = SIDE_FRONT;
 453                 else if (dot < -epsilon)
 454                         sides[i] = SIDE_BACK;
 455                 else
 456                 {
 457                         sides[i] = SIDE_ON;
 458                 }
 459                 counts[sides[i]]++;
 460         }
 461         sides[i] = sides[0];
 462         dists[i] = dists[0];
 463
 464         if (!counts[0])
 465         {
 466                 FreeWinding (in);
 467                 *inout = NULL;
 468                 return;
 469         }
 470         if (!counts[1])
 471                 return;         // inout stays the same
 472
 473         maxpts = in->numpoints+4;       // cant use counts[0]+2 because
 474                                                                 // of fp grouping errors
 475
 476         f = AllocWinding (maxpts);
 477
 478         for (i=0 ; i<in->numpoints ; i++)
 479         {
 480                 p1 = in->p[i];
 481
 482                 if (sides[i] == SIDE_ON)
 483                 {
 484                         VectorCopy (p1, f->p[f->numpoints]);
 485                         f->numpoints++;
 486                         continue;
 487                 }
 488
 489                 if (sides[i] == SIDE_FRONT)
 490                 {
 491                         VectorCopy (p1, f->p[f->numpoints]);
 492                         f->numpoints++;
 493                 }
 494
 495                 if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
 496                         continue;
 497
 498         // generate a split point
 499                 p2 = in->p[(i+1)%in->numpoints];
 500
 501                 dot = dists[i] / (dists[i]-dists[i+1]);
 502                 for (j=0 ; j<3 ; j++)
 503                 {       // avoid round off error when possible
 504                         if (normal[j] == 1)
 505                                 mid[j] = dist;
 506                         else if (normal[j] == -1)
 507                                 mid[j] = -dist;
 508                         else
 509                                 mid[j] = p1[j] + dot*(p2[j]-p1[j]);
 510                 }
 511
 512                 VectorCopy (mid, f->p[f->numpoints]);
 513                 f->numpoints++;
 514         }
 515
 516         if (f->numpoints > maxpts)
 517                 Error ("ClipWinding: points exceeded estimate");
 518         if (f->numpoints > MAX_POINTS_ON_WINDING)
 519                 Error ("ClipWinding: MAX_POINTS_ON_WINDING");
 520
 521         FreeWinding (in);
 522         *inout = f;
 523 }
 524
 525
 526 /*
 527 =================
 528 ChopWinding
 529
 530 Returns the fragment of in that is on the front side
 531 of the cliping plane.  The original is freed.
 532 =================
 533 */
 534 winding_t       *ChopWinding (winding_t *in, vec3_t normal, vec_t dist)
 535 {
 536         winding_t       *f, *b;
 537
 538         ClipWindingEpsilon (in, normal, dist, ON_EPSILON, &f, &b);
 539         FreeWinding (in);
 540         if (b)
 541                 FreeWinding (b);
 542         return f;
 543 }
 544
 545
 546 /*
 547 =================
 548 CheckWinding
 549
 550 =================
 551 */
 552 void CheckWinding (winding_t *w)
 553 {
 554         int             i, j;
 555         vec_t   *p1, *p2;
 556         vec_t   d, edgedist;
 557         vec3_t  dir, edgenormal, facenormal;
 558         vec_t   area;
 559         vec_t   facedist;
 560
 561         if (w->numpoints < 3)
 562                 Error ("CheckWinding: %i points",w->numpoints);
 563
 564         area = WindingArea(w);
 565         if (area < 1)
 566                 Error ("CheckWinding: %f area", area);
 567
 568         WindingPlane (w, facenormal, &facedist);
 569
 570         for (i=0 ; i<w->numpoints ; i++)
 571         {
 572                 p1 = w->p[i];
 573
 574                 for (j=0 ; j<3 ; j++)
 575                         if (p1[j] > MAX_WORLD_COORD || p1[j] < MIN_WORLD_COORD)
 576                                 Error ("CheckFace: MAX_WORLD_COORD exceeded: %f",p1[j]);
 577
 578                 j = i+1 == w->numpoints ? 0 : i+1;
 579
 580         // check the point is on the face plane
 581                 d = DotProduct (p1, facenormal) - facedist;
 582                 if (d < -ON_EPSILON || d > ON_EPSILON)
 583                         Error ("CheckWinding: point off plane");
 584
 585         // check the edge isnt degenerate
 586                 p2 = w->p[j];
 587                 VectorSubtract (p2, p1, dir);
 588
 589                 if (VectorLength (dir) < ON_EPSILON)
 590                         Error ("CheckWinding: degenerate edge");
 591
 592                 CrossProduct (facenormal, dir, edgenormal);
 593                 VectorNormalize (edgenormal, edgenormal);
 594                 edgedist = DotProduct (p1, edgenormal);
 595                 edgedist += ON_EPSILON;
 596
 597         // all other points must be on front side
 598                 for (j=0 ; j<w->numpoints ; j++)
 599                 {
 600                         if (j == i)
 601                                 continue;
 602                         d = DotProduct (w->p[j], edgenormal);
 603                         if (d > edgedist)
 604                                 Error ("CheckWinding: non-convex");
 605                 }
 606         }
 607 }
 608
 609
 610 /*
 611 ============
 612 WindingOnPlaneSide
 613 ============
 614 */
 615 int             WindingOnPlaneSide (winding_t *w, vec3_t normal, vec_t dist)
 616 {
 617         qboolean        front, back;
 618         int                     i;
 619         vec_t           d;
 620
 621         front = qfalse;
 622         back = qfalse;
 623         for (i=0 ; i<w->numpoints ; i++)
 624         {
 625                 d = DotProduct (w->p[i], normal) - dist;
 626                 if (d < -ON_EPSILON)
 627                 {
 628                         if (front)
 629                                 return SIDE_CROSS;
 630                         back = qtrue;
 631                         continue;
 632                 }
 633                 if (d > ON_EPSILON)
 634                 {
 635                         if (back)
 636                                 return SIDE_CROSS;
 637                         front = qtrue;
 638                         continue;
 639                 }
 640         }
 641
 642         if (back)
 643                 return SIDE_BACK;
 644         if (front)
 645                 return SIDE_FRONT;
 646         return SIDE_ON;
 647 }
 648
 649
 650 /*
 651 =================
 652 AddWindingToConvexHull
 653
 654 Both w and *hull are on the same plane
 655 =================
 656 */
 657 #define MAX_HULL_POINTS         128
 658 void    AddWindingToConvexHull( winding_t *w, winding_t **hull, vec3_t normal ) {
 659         int                     i, j, k;
 660         float           *p, *copy;
 661         vec3_t          dir;
 662         float           d;
 663         int                     numHullPoints, numNew;
 664         vec3_t          hullPoints[MAX_HULL_POINTS];
 665         vec3_t          newHullPoints[MAX_HULL_POINTS];
 666         vec3_t          hullDirs[MAX_HULL_POINTS];
 667         qboolean        hullSide[MAX_HULL_POINTS];
 668         qboolean        outside;
 669
 670         if ( !*hull ) {
 671                 *hull = CopyWinding( w );
 672                 return;
 673         }
 674
 675         numHullPoints = (*hull)->numpoints;
 676         memcpy( hullPoints, (*hull)->p, numHullPoints * sizeof(vec3_t) );
 677
 678         for ( i = 0 ; i < w->numpoints ; i++ ) {
 679                 p = w->p[i];
 680
 681                 // calculate hull side vectors
 682                 for ( j = 0 ; j < numHullPoints ; j++ ) {
 683                         k = ( j + 1 ) % numHullPoints;
 684
 685                         VectorSubtract( hullPoints[k], hullPoints[j], dir );
 686                         VectorNormalize( dir, dir );
 687                         CrossProduct( normal, dir, hullDirs[j] );
 688                 }
 689
 690                 outside = qfalse;
 691                 for ( j = 0 ; j < numHullPoints ; j++ ) {
 692                         VectorSubtract( p, hullPoints[j], dir );
 693                         d = DotProduct( dir, hullDirs[j] );
 694                         if ( d >= ON_EPSILON ) {
 695                                 outside = qtrue;
 696                         }
 697                         if ( d >= -ON_EPSILON ) {
 698                                 hullSide[j] = qtrue;
 699                         } else {
 700                                 hullSide[j] = qfalse;
 701                         }
 702                 }
 703
 704                 // if the point is effectively inside, do nothing
 705                 if ( !outside ) {
 706                         continue;
 707                 }
 708
 709                 // find the back side to front side transition
 710                 for ( j = 0 ; j < numHullPoints ; j++ ) {
 711                         if ( !hullSide[ j % numHullPoints ] && hullSide[ (j + 1) % numHullPoints ] ) {
 712                                 break;
 713                         }
 714                 }
 715                 if ( j == numHullPoints ) {
 716                         continue;
 717                 }
 718
 719                 // insert the point here
 720                 VectorCopy( p, newHullPoints[0] );
 721                 numNew = 1;
 722
 723                 // copy over all points that aren't double fronts
 724                 j = (j+1)%numHullPoints;
 725                 for ( k = 0 ; k < numHullPoints ; k++ ) {
 726                         if ( hullSide[ (j+k) % numHullPoints ] && hullSide[ (j+k+1) % numHullPoints ] ) {
 727                                 continue;
 728                         }
 729                         copy = hullPoints[ (j+k+1) % numHullPoints ];
 730                         VectorCopy( copy, newHullPoints[numNew] );
 731                         numNew++;
 732                 }
 733
 734                 numHullPoints = numNew;
 735                 memcpy( hullPoints, newHullPoints, numHullPoints * sizeof(vec3_t) );
 736         }
 737
 738         FreeWinding( *hull );
 739         w = AllocWinding( numHullPoints );
 740         w->numpoints = numHullPoints;
 741         *hull = w;
 742         memcpy( w->p, hullPoints, numHullPoints * sizeof(vec3_t) );
 743 }
 744
 745