collision.c

   1
   2 #include "quakedef.h"
   3
   4 typedef struct
   5 {
   6         // the hull we're tracing through
   7         const hull_t *hull;
   8
   9         // the trace structure to fill in
  10         trace_t *trace;
  11
  12         // start and end of the trace (in model space)
  13         double start[3];
  14         double end[3];
  15
  16         // end - start
  17         double dist[3];
  18 }
  19 RecursiveHullCheckTraceInfo_t;
  20
  21 // 1/32 epsilon to keep floating point happy
  22 #define DIST_EPSILON (0.03125)
  23
  24 #define HULLCHECKSTATE_EMPTY 0
  25 #define HULLCHECKSTATE_SOLID 1
  26 #define HULLCHECKSTATE_DONE 2
  27
  28 static int RecursiveHullCheck(RecursiveHullCheckTraceInfo_t *t, int num, double p1f, double p2f, double p1[3], double p2[3])
  29 {
  30         // status variables, these don't need to be saved on the stack when
  31         // recursing...  but are because this should be thread-safe
  32         // (note: tracing against a bbox is not thread-safe, yet)
  33         int ret;
  34         mplane_t *plane;
  35         double t1, t2;
  36
  37         // variables that need to be stored on the stack when recursing
  38         dclipnode_t *node;
  39         int side;
  40         double midf, mid[3];
  41
  42         // LordHavoc: a goto!  everyone flee in terror... :)
  43 loc0:
  44         // check for empty
  45         if (num < 0)
  46         {
  47                 t->trace->endcontents = num;
  48                 if (t->trace->thiscontents)
  49                 {
  50                         if (num == t->trace->thiscontents)
  51                                 t->trace->allsolid = false;
  52                         else
  53                         {
  54                                 // if the first leaf is solid, set startsolid
  55                                 if (t->trace->allsolid)
  56                                         t->trace->startsolid = true;
  57                                 return HULLCHECKSTATE_SOLID;
  58                         }
  59                         return HULLCHECKSTATE_EMPTY;
  60                 }
  61                 else
  62                 {
  63                         if (num != CONTENTS_SOLID)
  64                         {
  65                                 t->trace->allsolid = false;
  66                                 if (num == CONTENTS_EMPTY)
  67                                         t->trace->inopen = true;
  68                                 else
  69                                         t->trace->inwater = true;
  70                         }
  71                         else
  72                         {
  73                                 // if the first leaf is solid, set startsolid
  74                                 if (t->trace->allsolid)
  75                                         t->trace->startsolid = true;
  76                                 return HULLCHECKSTATE_SOLID;
  77                         }
  78                         return HULLCHECKSTATE_EMPTY;
  79                 }
  80         }
  81
  82         // find the point distances
  83         node = t->hull->clipnodes + num;
  84
  85         plane = t->hull->planes + node->planenum;
  86         if (plane->type < 3)
  87         {
  88                 t1 = p1[plane->type] - plane->dist;
  89                 t2 = p2[plane->type] - plane->dist;
  90         }
  91         else
  92         {
  93                 t1 = DotProduct (plane->normal, p1) - plane->dist;
  94                 t2 = DotProduct (plane->normal, p2) - plane->dist;
  95         }
  96
  97         if (t1 < 0)
  98         {
  99                 if (t2 < 0)
 100                 {
 101                         num = node->children[1];
 102                         goto loc0;
 103                 }
 104                 side = 1;
 105         }
 106         else
 107         {
 108                 if (t2 >= 0)
 109                 {
 110                         num = node->children[0];
 111                         goto loc0;
 112                 }
 113                 side = 0;
 114         }
 115
 116         // the line intersects, find intersection point
 117         // LordHavoc: this uses the original trace for maximum accuracy
 118         if (plane->type < 3)
 119         {
 120                 t1 = t->start[plane->type] - plane->dist;
 121                 t2 = t->end[plane->type] - plane->dist;
 122         }
 123         else
 124         {
 125                 t1 = DotProduct (plane->normal, t->start) - plane->dist;
 126                 t2 = DotProduct (plane->normal, t->end) - plane->dist;
 127         }
 128
 129         midf = t1 / (t1 - t2);
 130         midf = bound(p1f, midf, p2f);
 131         VectorMA(t->start, midf, t->dist, mid);
 132
 133         // recurse both sides, front side first
 134         ret = RecursiveHullCheck (t, node->children[side], p1f, midf, p1, mid);
 135         // if this side is not empty, return what it is (solid or done)
 136         if (ret != HULLCHECKSTATE_EMPTY)
 137                 return ret;
 138
 139         ret = RecursiveHullCheck (t, node->children[side ^ 1], midf, p2f, mid, p2);
 140         // if other side is not solid, return what it is (empty or done)
 141         if (ret != HULLCHECKSTATE_SOLID)
 142                 return ret;
 143
 144         // front is air and back is solid, this is the impact point...
 145         if (side)
 146         {
 147                 t->trace->plane.dist = -plane->dist;
 148                 VectorNegate (plane->normal, t->trace->plane.normal);
 149         }
 150         else
 151         {
 152                 t->trace->plane.dist = plane->dist;
 153                 VectorCopy (plane->normal, t->trace->plane.normal);
 154         }
 155
 156         // bias away from surface a bit
 157         t1 = DotProduct(t->trace->plane.normal, t->start) - (t->trace->plane.dist + DIST_EPSILON);
 158         t2 = DotProduct(t->trace->plane.normal, t->end) - (t->trace->plane.dist + DIST_EPSILON);
 159
 160         midf = t1 / (t1 - t2);
 161         t->trace->fraction = bound(0.0f, midf, 1.0);
 162
 163         VectorMA(t->start, t->trace->fraction, t->dist, t->trace->endpos);
 164
 165         return HULLCHECKSTATE_DONE;
 166 }
 167
 168 #if 0
 169 // used if start and end are the same
 170 static void RecursiveHullCheckPoint (RecursiveHullCheckTraceInfo_t *t, int num)
 171 {
 172         // If you can read this, you understand BSP trees
 173         while (num >= 0)
 174                 num = t->hull->clipnodes[num].children[((t->hull->planes[t->hull->clipnodes[num].planenum].type < 3) ? (t->start[t->hull->planes[t->hull->clipnodes[num].planenum].type]) : (DotProduct(t->hull->planes[t->hull->clipnodes[num].planenum].normal, t->start))) < t->hull->planes[t->hull->clipnodes[num].planenum].dist];
 175
 176         // check for empty
 177         t->trace->endcontents = num;
 178         if (t->trace->thiscontents)
 179         {
 180                 if (num == t->trace->thiscontents)
 181                         t->trace->allsolid = false;
 182                 else
 183                 {
 184                         // if the first leaf is solid, set startsolid
 185                         if (t->trace->allsolid)
 186                                 t->trace->startsolid = true;
 187                 }
 188         }
 189         else
 190         {
 191                 if (num != CONTENTS_SOLID)
 192                 {
 193                         t->trace->allsolid = false;
 194                         if (num == CONTENTS_EMPTY)
 195                                 t->trace->inopen = true;
 196                         else
 197                                 t->trace->inwater = true;
 198                 }
 199                 else
 200                 {
 201                         // if the first leaf is solid, set startsolid
 202                         if (t->trace->allsolid)
 203                                 t->trace->startsolid = true;
 204                 }
 205         }
 206 }
 207 #endif
 208
 209 void Collision_RoundUpToHullSize(const model_t *cmodel, const vec3_t inmins, const vec3_t inmaxs, vec3_t outmins, vec3_t outmaxs)
 210 {
 211         vec3_t size;
 212         const hull_t *hull;
 213
 214         VectorSubtract(inmaxs, inmins, size);
 215         if (cmodel->brushq1.ishlbsp)
 216         {
 217                 if (size[0] < 3)
 218                         hull = &cmodel->brushq1.hulls[0]; // 0x0x0
 219                 else if (size[0] <= 32)
 220                 {
 221                         if (size[2] < 54) // pick the nearest of 36 or 72
 222                                 hull = &cmodel->brushq1.hulls[3]; // 32x32x36
 223                         else
 224                                 hull = &cmodel->brushq1.hulls[1]; // 32x32x72
 225                 }
 226                 else
 227                         hull = &cmodel->brushq1.hulls[2]; // 64x64x64
 228         }
 229         else
 230         {
 231                 if (size[0] < 3)
 232                         hull = &cmodel->brushq1.hulls[0]; // 0x0x0
 233                 else if (size[0] <= 32)
 234                         hull = &cmodel->brushq1.hulls[1]; // 32x32x56
 235                 else
 236                         hull = &cmodel->brushq1.hulls[2]; // 64x64x88
 237         }
 238         VectorCopy(inmins, outmins);
 239         VectorAdd(inmins, hull->clip_size, outmaxs);
 240 }
 241
 242 static hull_t box_hull;
 243 static dclipnode_t box_clipnodes[6];
 244 static mplane_t box_planes[6];
 245
 246 void Collision_Init (void)
 247 {
 248         int             i;
 249         int             side;
 250
 251         //Set up the planes and clipnodes so that the six floats of a bounding box
 252         //can just be stored out and get a proper hull_t structure.
 253
 254         box_hull.clipnodes = box_clipnodes;
 255         box_hull.planes = box_planes;
 256         box_hull.firstclipnode = 0;
 257         box_hull.lastclipnode = 5;
 258
 259         for (i = 0;i < 6;i++)
 260         {
 261                 box_clipnodes[i].planenum = i;
 262
 263                 side = i&1;
 264
 265                 box_clipnodes[i].children[side] = CONTENTS_EMPTY;
 266                 if (i != 5)
 267                         box_clipnodes[i].children[side^1] = i + 1;
 268                 else
 269                         box_clipnodes[i].children[side^1] = CONTENTS_SOLID;
 270
 271                 box_planes[i].type = i>>1;
 272                 box_planes[i].normal[i>>1] = 1;
 273         }
 274 }
 275
 276 void Collision_ClipTrace_Box(trace_t *trace, const vec3_t cmins, const vec3_t cmaxs, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end)
 277 {
 278         RecursiveHullCheckTraceInfo_t rhc;
 279         // fill in a default trace
 280         memset(&rhc, 0, sizeof(rhc));
 281         memset(trace, 0, sizeof(trace_t));
 282         //To keep everything totally uniform, bounding boxes are turned into small
 283         //BSP trees instead of being compared directly.
 284         // create a temp hull from bounding box sizes
 285         box_planes[0].dist = cmaxs[0] - mins[0];
 286         box_planes[1].dist = cmins[0] - maxs[0];
 287         box_planes[2].dist = cmaxs[1] - mins[1];
 288         box_planes[3].dist = cmins[1] - maxs[1];
 289         box_planes[4].dist = cmaxs[2] - mins[2];
 290         box_planes[5].dist = cmins[2] - maxs[2];
 291         // trace a line through the generated clipping hull
 292         rhc.hull = &box_hull;
 293         rhc.trace = trace;
 294         rhc.trace->fraction = 1;
 295         rhc.trace->allsolid = true;
 296         VectorCopy(start, rhc.start);
 297         VectorCopy(end, rhc.end);
 298         VectorSubtract(rhc.end, rhc.start, rhc.dist);
 299         RecursiveHullCheck(&rhc, rhc.hull->firstclipnode, 0, 1, rhc.start, rhc.end);
 300 }
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316 void Collision_PrintBrushAsQHull(colbrushf_t *brush, const char *name)
 317 {
 318         int i;
 319         Con_Printf("3 %s\n%i\n", name, brush->numpoints);
 320         for (i = 0;i < brush->numpoints;i++)
 321                 Con_Printf("%g %g %g\n", brush->points[i].v[0], brush->points[i].v[1], brush->points[i].v[2]);
 322         // FIXME: optimize!
 323         Con_Printf("4\n%i\n", brush->numplanes);
 324         for (i = 0;i < brush->numplanes;i++)
 325                 Con_Printf("%g %g %g %g\n", brush->planes[i].normal[0], brush->planes[i].normal[1], brush->planes[i].normal[2], brush->planes[i].dist);
 326 }
 327
 328
 329 colbrushf_t *Collision_AllocBrushFloat(mempool_t *mempool, int numpoints, int numplanes)
 330 {
 331         colbrushf_t *brush;
 332         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpoints + sizeof(colplanef_t) * numplanes);
 333         brush->numpoints = numpoints;
 334         brush->numplanes = numplanes;
 335         brush->planes = (void *)(brush + 1);
 336         brush->points = (void *)(brush->planes + brush->numplanes);
 337         return brush;
 338 }
 339
 340 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 341 {
 342         int i;
 343         float edge0[3], edge1[3], normal[3], dist, bestdist;
 344         colpointf_t *p, *p2;
 345
 346         // choose best surface normal for polygon's plane
 347         bestdist = 0;
 348         for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
 349         {
 350                 VectorSubtract(p[-1].v, p[0].v, edge0);
 351                 VectorSubtract(p[1].v, p[0].v, edge1);
 352                 CrossProduct(edge0, edge1, normal);
 353                 dist = DotProduct(normal, normal);
 354                 if (i == 0 || bestdist < dist)
 355                 {
 356                         bestdist = dist;
 357                         VectorCopy(normal, brush->planes->normal);
 358                 }
 359         }
 360
 361         VectorNormalize(brush->planes->normal);
 362         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 363
 364         // negate plane to create other side
 365         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 366         brush->planes[1].dist = -brush->planes[0].dist;
 367         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
 368         {
 369                 VectorSubtract(p->v, p2->v, edge0);
 370                 CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
 371                 VectorNormalize(brush->planes[i + 2].normal);
 372                 brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
 373         }
 374
 375 #if 1
 376         // validity check - will be disabled later
 377         for (i = 0;i < brush->numplanes;i++)
 378         {
 379                 int j;
 380                 for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 381                         if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + (1.0 / 32.0))
 382                                 Con_Printf("Error in brush plane generation, plane %i\n", i);
 383         }
 384 #endif
 385 }
 386
 387 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points)
 388 {
 389         colbrushf_t *brush;
 390         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
 391         brush->numpoints = numpoints;
 392         brush->numplanes = numpoints + 2;
 393         brush->planes = (void *)(brush + 1);
 394         brush->points = (colpointf_t *)points;
 395         return brush;
 396 }
 397
 398 float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 399 {
 400         float dist, bestdist;
 401         bestdist = DotProduct(points->v, normal);
 402         points++;
 403         while(--numpoints)
 404         {
 405                 dist = DotProduct(points->v, normal);
 406                 if (bestdist > dist)
 407                         bestdist = dist;
 408                 points++;
 409         }
 410         return bestdist;
 411 }
 412
 413 float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 414 {
 415         float dist, bestdist;
 416         bestdist = DotProduct(points->v, normal);
 417         points++;
 418         while(--numpoints)
 419         {
 420                 dist = DotProduct(points->v, normal);
 421                 if (bestdist < dist)
 422                         bestdist = dist;
 423                 points++;
 424         }
 425         return bestdist;
 426 }
 427
 428 #define COLLISIONEPSILON (1.0f / 32.0f)
 429 #define COLLISIONEPSILON2 0//(1.0f / 32.0f)
 430
 431 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 432 float Collision_TraceBrushBrushFloat(const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end, float *impactnormal, int *startsolid, int *allsolid)
 433 {
 434         int nplane, nplane2, fstartsolid, fendsolid;
 435         float enterfrac, leavefrac, d1, d2, f, newimpactnormal[3];
 436         const colplanef_t *startplane, *endplane;
 437
 438         enterfrac = -1;
 439         leavefrac = 1;
 440         fstartsolid = true;
 441         fendsolid = true;
 442
 443         for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
 444         {
 445                 nplane2 = nplane;
 446                 if (nplane2 >= thatbrush_start->numplanes)
 447                 {
 448                         nplane2 -= thatbrush_start->numplanes;
 449                         startplane = thisbrush_start->planes + nplane2;
 450                         endplane = thisbrush_end->planes + nplane2;
 451                 }
 452                 else
 453                 {
 454                         startplane = thatbrush_start->planes + nplane2;
 455                         endplane = thatbrush_end->planes + nplane2;
 456                 }
 457                 d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 458                 d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - COLLISIONEPSILON2;
 459                 //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 460
 461                 f = d1 - d2;
 462                 if (f >= 0)
 463                 {
 464                         // moving into brush
 465                         if (d2 > 0)
 466                                 return 1;
 467                         if (d1 < 0)
 468                                 continue;
 469                         // enter
 470                         fstartsolid = false;
 471                         f = (d1 - COLLISIONEPSILON) / f;
 472                         f = bound(0, f, 1);
 473                         if (enterfrac < f)
 474                         {
 475                                 enterfrac = f;
 476                                 VectorBlend(startplane->normal, endplane->normal, enterfrac, newimpactnormal);
 477                         }
 478                 }
 479                 else if (f < 0)
 480                 {
 481                         // moving out of brush
 482                         if (d1 > 0)
 483                                 return 1;
 484                         if (d2 < 0)
 485                                 continue;
 486                         // leave
 487                         fendsolid = false;
 488                         f = (d1 + COLLISIONEPSILON) / f;
 489                         f = bound(0, f, 1);
 490                         if (leavefrac > f)
 491                                 leavefrac = f;
 492                 }
 493         }
 494
 495         if (fstartsolid)
 496         {
 497                 if (startsolid)
 498                         *startsolid = true;
 499                 if (fendsolid && allsolid)
 500                         *allsolid = true;
 501         }
 502
 503         // LordHavoc: we need an epsilon nudge here because for a point trace the
 504         // penetrating line segment is normally zero length if this brush was
 505         // generated from a polygon (infinitely thin), and could even be slightly
 506         // positive or negative due to rounding errors in that case.
 507         if (enterfrac > -1 && enterfrac < 1 && enterfrac - (1.0f / 1024.0f) <= leavefrac)
 508         {
 509                 //if (enterfrac < (1.0f / 1024.0f))
 510                 //      enterfrac = 0;
 511                 enterfrac = bound(0, enterfrac, 1);
 512                 VectorCopy(newimpactnormal, impactnormal);
 513                 return enterfrac;
 514         }
 515         return 1;
 516 }
 517
 518 static colplanef_t polyf_planes[256 + 2];
 519 static colbrushf_t polyf_brush;
 520
 521 float Collision_TraceBrushPolygonFloat(const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, float *impactnormal, int *startsolid, int *allsolid)
 522 {
 523         if (numpoints > 256)
 524         {
 525                 Con_Printf("Polygon with more than 256 points not supported yet (fixme!)\n");
 526                 return 1;
 527         }
 528         polyf_brush.numpoints = numpoints;
 529         polyf_brush.numplanes = numpoints + 2;
 530         polyf_brush.points = (colpointf_t *)points;
 531         polyf_brush.planes = polyf_planes;
 532         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 533         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 534         return Collision_TraceBrushBrushFloat(thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush, impactnormal, startsolid, allsolid);
 535 }
 536
 537 static colpointf_t polyf_pointsstart[256], polyf_pointsend[256];
 538 static colplanef_t polyf_planesstart[256 + 2], polyf_planesend[256 + 2];
 539 static colbrushf_t polyf_brushstart, polyf_brushend;
 540
 541 float Collision_TraceBrushPolygonTransformFloat(const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, float *impactnormal, const matrix4x4_t *polygonmatrixstart, const matrix4x4_t *polygonmatrixend, int *startsolid, int *allsolid)
 542 {
 543         int i;
 544         if (numpoints > 256)
 545         {
 546                 Con_Printf("Polygon with more than 256 points not supported yet (fixme!)\n");
 547                 return 1;
 548         }
 549         polyf_brushstart.numpoints = numpoints;
 550         polyf_brushstart.numplanes = numpoints + 2;
 551         polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
 552         polyf_brushstart.planes = polyf_planesstart;
 553         for (i = 0;i < numpoints;i++)
 554                 Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
 555         polyf_brushend.numpoints = numpoints;
 556         polyf_brushend.numplanes = numpoints + 2;
 557         polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
 558         polyf_brushend.planes = polyf_planesend;
 559         for (i = 0;i < numpoints;i++)
 560                 Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
 561         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
 562         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
 563
 564         //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
 565         //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
 566
 567         return Collision_TraceBrushBrushFloat(thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend, impactnormal, startsolid, allsolid);
 568 }
 569
 570 colbrushd_t *Collision_AllocBrushDouble(mempool_t *mempool, int numpoints, int numplanes)
 571 {
 572         colbrushd_t *brush;
 573         brush = Mem_Alloc(mempool, sizeof(colbrushd_t) + sizeof(colpointd_t) * numpoints + sizeof(colplaned_t) * numplanes);
 574         brush->numpoints = numpoints;
 575         brush->numplanes = numplanes;
 576         brush->planes = (void *)(brush + 1);
 577         brush->points = (void *)(brush->planes + brush->numplanes);
 578         return brush;
 579 }
 580
 581 void Collision_CalcPlanesForPolygonBrushDouble(colbrushd_t *brush)
 582 {
 583         int i;
 584         double edge0[3], edge1[3], normal[3], dist, bestdist;
 585         colpointd_t *p, *p2;
 586
 587         // choose best surface normal for polygon's plane
 588         bestdist = 0;
 589         for (i = 2, p = brush->points + 2;i < brush->numpoints;i++, p++)
 590         {
 591                 VectorSubtract(p[-1].v, p[0].v, edge0);
 592                 VectorSubtract(p[1].v, p[0].v, edge1);
 593                 CrossProduct(edge0, edge1, normal);
 594                 dist = DotProduct(normal, normal);
 595                 if (i == 2 || bestdist < dist)
 596                 {
 597                         bestdist = dist;
 598                         VectorCopy(normal, brush->planes->normal);
 599                 }
 600         }
 601
 602         VectorNormalize(brush->planes->normal);
 603         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 604
 605         // negate plane to create other side
 606         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 607         brush->planes[1].dist = -brush->planes[0].dist;
 608         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points + 2;i < brush->numpoints;i++, p = p2, p2++)
 609         {
 610                 VectorSubtract(p->v, p2->v, edge0);
 611                 CrossProduct(edge0, brush->planes->normal, brush->planes[i].normal);
 612                 VectorNormalize(brush->planes[i].normal);
 613                 brush->planes[i].dist = DotProduct(p->v, brush->planes[i].normal);
 614         }
 615
 616 #if 1
 617         // validity check - will be disabled later
 618         for (i = 0;i < brush->numplanes;i++)
 619         {
 620                 int j;
 621                 for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 622                         if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + (1.0 / 32.0))
 623                                 Con_Printf("Error in brush plane generation, plane %i\n");
 624         }
 625 #endif
 626 }
 627
 628 colbrushd_t *Collision_AllocBrushFromPermanentPolygonDouble(mempool_t *mempool, int numpoints, double *points)
 629 {
 630         colbrushd_t *brush;
 631         brush = Mem_Alloc(mempool, sizeof(colbrushd_t) + sizeof(colplaned_t) * (numpoints + 2));
 632         brush->numpoints = numpoints;
 633         brush->numplanes = numpoints + 2;
 634         brush->planes = (void *)(brush + 1);
 635         brush->points = (colpointd_t *)points;
 636         return brush;
 637 }
 638
 639
 640 double nearestplanedist_double(const double *normal, const colpointd_t *points, int numpoints)
 641 {
 642         double dist, bestdist;
 643         bestdist = DotProduct(points->v, normal);
 644         points++;
 645         while(--numpoints)
 646         {
 647                 dist = DotProduct(points->v, normal);
 648                 if (bestdist > dist)
 649                         bestdist = dist;
 650                 points++;
 651         }
 652         return bestdist;
 653 }
 654
 655 double furthestplanedist_double(const double *normal, const colpointd_t *points, int numpoints)
 656 {
 657         double dist, bestdist;
 658         bestdist = DotProduct(points->v, normal);
 659         points++;
 660         while(--numpoints)
 661         {
 662                 dist = DotProduct(points->v, normal);
 663                 if (bestdist < dist)
 664                         bestdist = dist;
 665                 points++;
 666         }
 667         return bestdist;
 668 }
 669
 670 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 671 double Collision_TraceBrushBrushDouble(const colbrushd_t *thisbrush_start, const colbrushd_t *thisbrush_end, const colbrushd_t *thatbrush_start, const colbrushd_t *thatbrush_end, double *impactnormal)
 672 {
 673         int nplane;
 674         double enterfrac, leavefrac, d1, d2, f, newimpactnormal[3];
 675         const colplaned_t *startplane, *endplane;
 676
 677         enterfrac = -1;
 678         leavefrac = 1;
 679
 680         for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
 681         {
 682                 startplane = thatbrush_start->planes + nplane;
 683                 endplane = thatbrush_end->planes + nplane;
 684                 d1 = nearestplanedist_double(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_double(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 685                 d2 = nearestplanedist_double(endplane->normal, thisbrush_end->points, thisbrush_start->numpoints) - furthestplanedist_double(endplane->normal, thatbrush_end->points, thatbrush_start->numpoints) - (1.0 / 32.0);
 686
 687                 f = d1 - d2;
 688                 if (f >= 0)
 689                 {
 690                         // moving into brush
 691                         if (d2 > 0)
 692                                 return 1;
 693                         if (d1 < 0)
 694                                 continue;
 695                         // enter
 696                         f = d1 / f;
 697                         if (enterfrac < f)
 698                         {
 699                                 enterfrac = f;
 700                                 VectorSubtract(endplane->normal, startplane->normal, newimpactnormal);
 701                                 VectorMA(startplane->normal, enterfrac, impactnormal, newimpactnormal);
 702                         }
 703                 }
 704                 else
 705                 {
 706                         // moving out of brush
 707                         if (d1 > 0)
 708                                 return 1;
 709                         if (d2 < 0)
 710                                 continue;
 711                         // leave
 712                         f = d1 / f;
 713                         if (leavefrac > f)
 714                                 leavefrac = f;
 715                 }
 716         }
 717
 718         for (nplane = 0;nplane < thisbrush_start->numplanes;nplane++)
 719         {
 720                 startplane = thisbrush_start->planes + nplane;
 721                 endplane = thisbrush_end->planes + nplane;
 722                 d1 = nearestplanedist_double(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_double(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 723                 d2 = nearestplanedist_double(endplane->normal, thisbrush_end->points, thisbrush_start->numpoints) - furthestplanedist_double(endplane->normal, thatbrush_end->points, thatbrush_start->numpoints) - (1.0 / 32.0);
 724
 725                 f = d1 - d2;
 726                 if (f >= 0)
 727                 {
 728                         // moving into brush
 729                         if (d2 > 0)
 730                                 return 1;
 731                         if (d1 < 0)
 732                                 continue;
 733                         // enter
 734                         f = d1 / f;
 735                         if (enterfrac < f)
 736                         {
 737                                 enterfrac = f;
 738                                 VectorSubtract(endplane->normal, startplane->normal, newimpactnormal);
 739                                 VectorMA(startplane->normal, enterfrac, impactnormal, newimpactnormal);
 740                         }
 741                 }
 742                 else
 743                 {
 744                         // moving out of brush
 745                         if (d1 > 0)
 746                                 return 1;
 747                         if (d2 < 0)
 748                                 continue;
 749                         // leave
 750                         f = d1 / f;
 751                         if (leavefrac > f)
 752                                 leavefrac = f;
 753                 }
 754         }
 755
 756         // LordHavoc: we need an epsilon nudge here because for a point trace the
 757         // penetrating line segment is normally zero length if this brush was
 758         // generated from a polygon (infinitely thin), and could even be slightly
 759         // positive or negative due to rounding errors in that case.
 760         enterfrac -= (1.0 / 16384.0);
 761         if (leavefrac - enterfrac >= 0 && enterfrac > -1)
 762         {
 763                 VectorCopy(newimpactnormal, impactnormal);
 764                 enterfrac = bound(0, enterfrac, 1);
 765                 return enterfrac;
 766         }
 767         return 1;
 768 }
 769
 770 static colplaned_t polyd_planes[256 + 2];
 771 static colbrushd_t polyd_brush;
 772 double Collision_TraceBrushPolygonDouble(const colbrushd_t *thisbrush_start, const colbrushd_t *thisbrush_end, int numpoints, const double *points, double *impactnormal)
 773 {
 774         if (numpoints > 256)
 775         {
 776                 Con_Printf("Polygon with more than 256 points not supported yet (fixme!)\n");
 777                 return 1;
 778         }
 779         polyd_brush.numpoints = numpoints;
 780         polyd_brush.numplanes = numpoints + 2;
 781         polyd_brush.points = (colpointd_t *)points;
 782         polyd_brush.planes = polyd_planes;
 783         Collision_CalcPlanesForPolygonBrushDouble(&polyd_brush);
 784         return Collision_TraceBrushBrushDouble(thisbrush_start, thisbrush_end, &polyd_brush, &polyd_brush, impactnormal);
 785 }
 786
 787
 788
 789
 790 typedef struct colbrushbmodelinfo_s
 791 {
 792         model_t *model;
 793         const matrix4x4_t *modelmatrixstart;
 794         const matrix4x4_t *modelmatrixend;
 795         const colbrushf_t *thisbrush_start;
 796         const colbrushf_t *thisbrush_end;
 797         float impactnormal[3];
 798         float tempimpactnormal[3];
 799         float fraction;
 800         int startsolid;
 801         int allsolid;
 802 }
 803 colbrushbmodelinfo_t;
 804
 805 static int colframecount = 1;
 806
 807 void Collision_RecursiveTraceBrushNode(colbrushbmodelinfo_t *info, mnode_t *node)
 808 {
 809         if (node->contents)
 810         {
 811                 // collide with surfaces marked by this leaf
 812                 int i, *mark;
 813                 float result;
 814                 mleaf_t *leaf = (mleaf_t *)node;
 815                 msurface_t *surf;
 816                 for (i = 0, mark = leaf->firstmarksurface;i < leaf->nummarksurfaces;i++, mark++)
 817                 {
 818                         surf = info->model->brushq1.surfaces + *mark;
 819                         // don't check a surface twice
 820                         if (surf->colframe != colframecount)
 821                         {
 822                                 surf->colframe = colframecount;
 823                                 if (surf->flags & SURF_SOLIDCLIP)
 824                                 {
 825                                         result = Collision_TraceBrushPolygonFloat(info->thisbrush_start, info->thisbrush_end, surf->poly_numverts, surf->poly_verts, info->tempimpactnormal, &info->startsolid, &info->allsolid);
 826                                         //result = Collision_TraceBrushPolygonTransformFloat(info->thisbrush_start, info->thisbrush_end, surf->poly_numverts, surf->poly_verts, info->tempimpactnormal, info->modelmatrixstart, info->modelmatrixend, &info->startsolid, &info->allsolid);
 827                                         if (info->fraction > result)
 828                                         {
 829                                                 info->fraction = result;
 830                                                 // use the surface's plane instead of the actual
 831                                                 // collision plane because the actual collision plane
 832                                                 // might be to the side (on a seam between polygons)
 833                                                 // or something, we want objects to bounce off the
 834                                                 // front...
 835                                                 //if (surf->flags & SURF_PLANEBACK)
 836                                                 //      VectorNegate(surf->plane->normal, info->impactnormal);
 837                                                 //else
 838                                                 //      VectorCopy(surf->plane->normal, info->impactnormal);
 839                                                 VectorCopy(info->tempimpactnormal, info->impactnormal);
 840                                         }
 841                                 }
 842                         }
 843                 }
 844         }
 845         else
 846         {
 847                 // recurse down node sides
 848                 int i;
 849                 float dist;
 850                 colpointf_t *ps, *pe;
 851                 // FIXME? if TraceBrushPolygonTransform were to be made usable, the
 852                 // node planes would need to be transformed too
 853                 dist = node->plane->dist - (1.0f / 8.0f);
 854                 for (i = 0, ps = info->thisbrush_start->points, pe = info->thisbrush_end->points;i < info->thisbrush_start->numpoints;i++, ps++, pe++)
 855                 {
 856                         if (DotProduct(ps->v, node->plane->normal) > dist || DotProduct(pe->v, node->plane->normal) > dist)
 857                         {
 858                                 Collision_RecursiveTraceBrushNode(info, node->children[0]);
 859                                 break;
 860                         }
 861                 }
 862                 dist = node->plane->dist + (1.0f / 8.0f);
 863                 for (i = 0, ps = info->thisbrush_start->points, pe = info->thisbrush_end->points;i < info->thisbrush_start->numpoints;i++, ps++, pe++)
 864                 {
 865                         if (DotProduct(ps->v, node->plane->normal) < dist || DotProduct(pe->v, node->plane->normal) < dist)
 866                         {
 867                                 Collision_RecursiveTraceBrushNode(info, node->children[1]);
 868                                 break;
 869                         }
 870                 }
 871         }
 872 }
 873
 874 float Collision_TraceBrushBModel(const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, model_t *model, float *impactnormal, int *startsolid, int *allsolid)
 875 {
 876         colbrushbmodelinfo_t info;
 877         colframecount++;
 878         info.model = model;
 879         info.thisbrush_start = thisbrush_start;
 880         info.thisbrush_end = thisbrush_end;
 881         info.fraction = 1;
 882         info.startsolid = false;
 883         info.allsolid = false;
 884         Collision_RecursiveTraceBrushNode(&info, model->brushq1.nodes + model->brushq1.hulls[0].firstclipnode);
 885         if (info.fraction < 1)
 886                 VectorCopy(info.impactnormal, impactnormal);
 887         if (startsolid)
 888                 *startsolid = info.startsolid;
 889         if (allsolid)
 890                 *allsolid = info.allsolid;
 891         return info.fraction;
 892 }
 893
 894 float Collision_TraceBrushBModelTransform(const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, model_t *model, float *impactnormal, const matrix4x4_t *modelmatrixstart, const matrix4x4_t *modelmatrixend, int *startsolid, int *allsolid)
 895 {
 896         colbrushbmodelinfo_t info;
 897         colframecount++;
 898         info.model = model;
 899         info.modelmatrixstart = modelmatrixstart;
 900         info.modelmatrixend = modelmatrixend;
 901         info.thisbrush_start = thisbrush_start;
 902         info.thisbrush_end = thisbrush_end;
 903         info.fraction = 1;
 904         info.startsolid = false;
 905         info.allsolid = false;
 906         Collision_RecursiveTraceBrushNode(&info, model->brushq1.nodes);
 907         if (info.fraction < 1)
 908                 VectorCopy(info.impactnormal, impactnormal);
 909         if (startsolid)
 910                 *startsolid = info.startsolid;
 911         if (allsolid)
 912                 *allsolid = info.allsolid;
 913         return info.fraction;
 914 }
 915
 916
 917
 918 #define MAX_BRUSHFORBOX 16
 919 static int brushforbox_index = 0;
 920 static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
 921 static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
 922 static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
 923
 924 void Collision_InitBrushForBox(void)
 925 {
 926         int i;
 927         for (i = 0;i < MAX_BRUSHFORBOX;i++)
 928         {
 929                 brushforbox_brush[i].numpoints = 8;
 930                 brushforbox_brush[i].numplanes = 6;
 931                 brushforbox_brush[i].points = brushforbox_point + i * 8;
 932                 brushforbox_brush[i].planes = brushforbox_plane + i * 6;
 933         }
 934 }
 935
 936 colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs)
 937 {
 938         int i;
 939         vec3_t v;
 940         colbrushf_t *brush;
 941         if (brushforbox_brush[0].numpoints == 0)
 942                 Collision_InitBrushForBox();
 943         brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
 944         // FIXME: optimize
 945         for (i = 0;i < 8;i++)
 946         {
 947                 v[0] = i & 1 ? maxs[0] : mins[0];
 948                 v[1] = i & 2 ? maxs[1] : mins[1];
 949                 v[2] = i & 4 ? maxs[2] : mins[2];
 950                 Matrix4x4_Transform(matrix, v, brush->points[i].v);
 951         }
 952         // FIXME: optimize!
 953         for (i = 0;i < 6;i++)
 954         {
 955                 VectorClear(v);
 956                 v[i >> 1] = i & 1 ? 1 : -1;
 957                 Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
 958                 VectorNormalize(brush->planes[i].normal);
 959                 brush->planes[i].dist = furthestplanedist_float(brush->planes[i].normal, brush->points, brush->numpoints);
 960         }
 961         return brush;
 962 }
 963
 964 void Collision_PolygonClipTrace (trace_t *trace, const void *cent, model_t *cmodel, const vec3_t corigin, const vec3_t cangles, const vec3_t cmins, const vec3_t cmaxs, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end)
 965 {
 966         vec3_t impactnormal;
 967         //vec3_t mins2, maxs2;
 968         matrix4x4_t cmatrix, cimatrix, startmatrix, endmatrix;
 969         matrix4x4_t mstartmatrix, mendmatrix, identitymatrix;
 970         colbrushf_t *thisbrush_start, *thisbrush_end, *cbrush;
 971
 972         Matrix4x4_CreateFromQuakeEntity(&cmatrix, corigin[0], corigin[1], corigin[2], cangles[0], cangles[1], cangles[2], 1);
 973         Matrix4x4_Invert_Simple(&cimatrix, &cmatrix);
 974         Matrix4x4_CreateTranslate(&startmatrix, start[0], start[1], start[2]);
 975         Matrix4x4_CreateTranslate(&endmatrix, end[0], end[1], end[2]);
 976
 977         Matrix4x4_CreateIdentity(&identitymatrix);
 978         Matrix4x4_Concat(&mstartmatrix, &cimatrix, &startmatrix);
 979         Matrix4x4_Concat(&mendmatrix, &cimatrix, &endmatrix);
 980         thisbrush_start = Collision_BrushForBox(&mstartmatrix, mins, maxs);
 981         //mins2[0] = mins[0] - 0.0625;mins2[1] = mins[1] - 0.0625;mins2[2] = mins[2] - 0.0625;
 982         //maxs2[0] = maxs[0] + 0.0625;maxs2[1] = maxs[1] + 0.0625;maxs2[2] = maxs[2] + 0.0625;
 983         thisbrush_end = Collision_BrushForBox(&mendmatrix, mins, maxs);
 984
 985         //Collision_PrintBrushAsQHull(thisbrush_start, "thisbrush_start");
 986         //Collision_PrintBrushAsQHull(thisbrush_end, "thisbrush_end");
 987         memset (trace, 0, sizeof(trace_t));
 988         if (cmodel && cmodel->type == mod_brush)
 989         {
 990                 // brush model
 991                 trace->fraction = Collision_TraceBrushBModel(thisbrush_start, thisbrush_end, cmodel, impactnormal, &trace->startsolid, &trace->allsolid);
 992                 //trace->fraction = Collision_TraceBrushBModelTransform(thisbrush_start, thisbrush_end, cmodel, trace->plane.normal, &cmatrix, &cmatrix, &trace->startsolid, &trace->allsolid);
 993         }
 994         else
 995         {
 996                 // bounding box
 997                 cbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs);
 998                 trace->fraction = Collision_TraceBrushBrushFloat(thisbrush_start, thisbrush_end, cbrush, cbrush, impactnormal, &trace->startsolid, &trace->allsolid);
 999                 //cbrush = Collision_BrushForBox(&cmatrix, cmins, cmaxs);
1000                 //trace->fraction = Collision_TraceBrushBrushFloat(thisbrush_start, thisbrush_end, cbrush, cbrush, trace->plane.normal, &trace->startsolid, &trace->allsolid);
1001         }
1002
1003         if (trace->fraction < 0 || trace->fraction > 1)
1004                 Con_Printf("fraction out of bounds %f %s:%d\n", trace->fraction, __FILE__, __LINE__);
1005
1006         if (trace->fraction < 1)
1007         {
1008                 trace->ent = (void *) cent;
1009                 VectorBlend(start, end, trace->fraction, trace->endpos);
1010                 Matrix4x4_Transform(&cmatrix, impactnormal, trace->plane.normal);
1011                 VectorNormalize(trace->plane.normal);
1012                 //Con_Printf("fraction %f normal %f %f %f\n", trace->fraction, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2]);
1013         }
1014         else
1015                 VectorCopy(end, trace->endpos);
1016 }
1017
1018
1019 // LordHavoc: currently unused and not yet tested
1020 // note: this can be used for tracing a moving sphere vs a stationary sphere,
1021 // by simply adding the moving sphere's radius to the sphereradius parameter,
1022 // all the results are correct (impactpoint, impactnormal, and fraction)
1023 float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
1024 {
1025         double dir[3], scale, v[3], deviationdist, impactdist, linelength;
1026         // make sure the impactpoint and impactnormal are valid even if there is
1027         // no collision
1028         impactpoint[0] = lineend[0];
1029         impactpoint[1] = lineend[1];
1030         impactpoint[2] = lineend[2];
1031         impactnormal[0] = 0;
1032         impactnormal[1] = 0;
1033         impactnormal[2] = 0;
1034         // calculate line direction
1035         dir[0] = lineend[0] - linestart[0];
1036         dir[1] = lineend[1] - linestart[1];
1037         dir[2] = lineend[2] - linestart[2];
1038         // normalize direction
1039         linelength = sqrt(dir[0] * dir[0] + dir[1] * dir[1] + dir[2] * dir[2]);
1040         if (linelength)
1041         {
1042                 scale = 1.0 / linelength;
1043                 dir[0] *= scale;
1044                 dir[1] *= scale;
1045                 dir[2] *= scale;
1046         }
1047         // this dotproduct calculates the distance along the line at which the
1048         // sphere origin is (nearest point to the sphere origin on the line)
1049         impactdist = dir[0] * (sphereorigin[0] - linestart[0]) + dir[1] * (sphereorigin[1] - linestart[1]) + dir[2] * (sphereorigin[2] - linestart[2]);
1050         // calculate point on line at that distance, and subtract the
1051         // sphereorigin from it, so we have a vector to measure for the distance
1052         // of the line from the sphereorigin (deviation, how off-center it is)
1053         v[0] = linestart[0] + impactdist * dir[0] - sphereorigin[0];
1054         v[1] = linestart[1] + impactdist * dir[1] - sphereorigin[1];
1055         v[2] = linestart[2] + impactdist * dir[2] - sphereorigin[2];
1056         deviationdist = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
1057         // if outside the radius, it's a miss for sure
1058         // (we do this comparison using squared radius to avoid a sqrt)
1059         if (deviationdist > sphereradius*sphereradius)
1060                 return 1; // miss (off to the side)
1061         // nudge back to find the correct impact distance
1062         impactdist += (sqrt(deviationdist) - sphereradius);
1063         if (impactdist >= linelength)
1064                 return 1; // miss (not close enough)
1065         if (impactdist < 0)
1066                 return 1; // miss (linestart is past or inside sphere)
1067         // calculate new impactpoint
1068         impactpoint[0] = linestart[0] + impactdist * dir[0];
1069         impactpoint[1] = linestart[1] + impactdist * dir[1];
1070         impactpoint[2] = linestart[2] + impactdist * dir[2];
1071         // calculate impactnormal (surface normal at point of impact)
1072         impactnormal[0] = impactpoint[0] - sphereorigin[0];
1073         impactnormal[1] = impactpoint[1] - sphereorigin[1];
1074         impactnormal[2] = impactpoint[2] - sphereorigin[2];
1075         // normalize impactnormal
1076         scale = impactnormal[0] * impactnormal[0] + impactnormal[1] * impactnormal[1] + impactnormal[2] * impactnormal[2];
1077         if (scale)
1078         {
1079                 scale = 1.0 / sqrt(scale);
1080                 impactnormal[0] *= scale;
1081                 impactnormal[1] *= scale;
1082                 impactnormal[2] *= scale;
1083         }
1084         // return fraction of movement distance
1085         return impactdist / linelength;
1086 }
1087