collision.c

   1
   2 #include "quakedef.h"
   3 #include "winding.h"
   4
   5 #define COLLISION_SNAPSCALE (32.0f)
   6 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
   7
   8 cvar_t collision_impactnudge = {0, "collision_impactnudge", "0.03125"};
   9 cvar_t collision_startnudge = {0, "collision_startnudge", "0"};
  10 cvar_t collision_endnudge = {0, "collision_endnudge", "0"};
  11 cvar_t collision_enternudge = {0, "collision_enternudge", "0"};
  12 cvar_t collision_leavenudge = {0, "collision_leavenudge", "0"};
  13
  14 #if 0
  15 typedef struct
  16 {
  17         // the hull we're tracing through
  18         const hull_t *hull;
  19
  20         // the trace structure to fill in
  21         trace_t *trace;
  22
  23         // start and end of the trace (in model space)
  24         double start[3];
  25         double end[3];
  26
  27         // end - start
  28         double dist[3];
  29
  30         // overrides the CONTENTS_SOLID in the box bsp tree
  31         int boxsupercontents;
  32 }
  33 RecursiveHullCheckTraceInfo_t;
  34
  35 #define HULLCHECKSTATE_EMPTY 0
  36 #define HULLCHECKSTATE_SOLID 1
  37 #define HULLCHECKSTATE_DONE 2
  38
  39 static int RecursiveHullCheck(RecursiveHullCheckTraceInfo_t *t, int num, double p1f, double p2f, double p1[3], double p2[3])
  40 {
  41         // status variables, these don't need to be saved on the stack when
  42         // recursing...  but are because this should be thread-safe
  43         // (note: tracing against a bbox is not thread-safe, yet)
  44         int ret;
  45         mplane_t *plane;
  46         double t1, t2;
  47
  48         // variables that need to be stored on the stack when recursing
  49         dclipnode_t *node;
  50         int side;
  51         double midf, mid[3];
  52
  53         // LordHavoc: a goto!  everyone flee in terror... :)
  54 loc0:
  55         // check for empty
  56         if (num < 0)
  57         {
  58                 num = Mod_Q1BSP_SuperContentsFromNativeContents(NULL, num);
  59                 if (!t->trace->startfound)
  60                 {
  61                         t->trace->startfound = true;
  62                         t->trace->startsupercontents |= num;
  63                 }
  64                 if (num & SUPERCONTENTS_LIQUIDSMASK)
  65                         t->trace->inwater = true;
  66                 if (num == 0)
  67                         t->trace->inopen = true;
  68                 if (num & t->trace->hitsupercontentsmask)
  69                 {
  70                         // if the first leaf is solid, set startsolid
  71                         if (t->trace->allsolid)
  72                                 t->trace->startsolid = true;
  73 #if COLLISIONPARANOID >= 3
  74                         Con_Print("S");
  75 #endif
  76                         return HULLCHECKSTATE_SOLID;
  77                 }
  78                 else
  79                 {
  80                         t->trace->allsolid = false;
  81 #if COLLISIONPARANOID >= 3
  82                         Con_Print("E");
  83 #endif
  84                         return HULLCHECKSTATE_EMPTY;
  85                 }
  86         }
  87
  88         // find the point distances
  89         node = t->hull->clipnodes + num;
  90
  91         plane = t->hull->planes + node->planenum;
  92         if (plane->type < 3)
  93         {
  94                 t1 = p1[plane->type] - plane->dist;
  95                 t2 = p2[plane->type] - plane->dist;
  96         }
  97         else
  98         {
  99                 t1 = DotProduct (plane->normal, p1) - plane->dist;
 100                 t2 = DotProduct (plane->normal, p2) - plane->dist;
 101         }
 102
 103         if (t1 < 0)
 104         {
 105                 if (t2 < 0)
 106                 {
 107 #if COLLISIONPARANOID >= 3
 108                         Con_Print("<");
 109 #endif
 110                         num = node->children[1];
 111                         goto loc0;
 112                 }
 113                 side = 1;
 114         }
 115         else
 116         {
 117                 if (t2 >= 0)
 118                 {
 119 #if COLLISIONPARANOID >= 3
 120                         Con_Print(">");
 121 #endif
 122                         num = node->children[0];
 123                         goto loc0;
 124                 }
 125                 side = 0;
 126         }
 127
 128         // the line intersects, find intersection point
 129         // LordHavoc: this uses the original trace for maximum accuracy
 130 #if COLLISIONPARANOID >= 3
 131         Con_Print("M");
 132 #endif
 133         if (plane->type < 3)
 134         {
 135                 t1 = t->start[plane->type] - plane->dist;
 136                 t2 = t->end[plane->type] - plane->dist;
 137         }
 138         else
 139         {
 140                 t1 = DotProduct (plane->normal, t->start) - plane->dist;
 141                 t2 = DotProduct (plane->normal, t->end) - plane->dist;
 142         }
 143
 144         midf = t1 / (t1 - t2);
 145         midf = bound(p1f, midf, p2f);
 146         VectorMA(t->start, midf, t->dist, mid);
 147
 148         // recurse both sides, front side first
 149         ret = RecursiveHullCheck (t, node->children[side], p1f, midf, p1, mid);
 150         // if this side is not empty, return what it is (solid or done)
 151         if (ret != HULLCHECKSTATE_EMPTY)
 152                 return ret;
 153
 154         ret = RecursiveHullCheck (t, node->children[side ^ 1], midf, p2f, mid, p2);
 155         // if other side is not solid, return what it is (empty or done)
 156         if (ret != HULLCHECKSTATE_SOLID)
 157                 return ret;
 158
 159         // front is air and back is solid, this is the impact point...
 160         if (side)
 161         {
 162                 t->trace->plane.dist = -plane->dist;
 163                 VectorNegate (plane->normal, t->trace->plane.normal);
 164         }
 165         else
 166         {
 167                 t->trace->plane.dist = plane->dist;
 168                 VectorCopy (plane->normal, t->trace->plane.normal);
 169         }
 170
 171         // calculate the true fraction
 172         t1 = DotProduct(t->trace->plane.normal, t->start) - t->trace->plane.dist - collision_startnudge.value;
 173         t2 = DotProduct(t->trace->plane.normal, t->end) - t->trace->plane.dist - collision_endnudge.value;
 174         midf = t1 / (t1 - t2);
 175         t->trace->realfraction = bound(0, midf, 1);
 176
 177         // calculate the return fraction which is nudged off the surface a bit
 178         midf = (t1 - collision_impactnudge.value) / (t1 - t2);
 179         t->trace->fraction = bound(0, midf, 1);
 180
 181 #if COLLISIONPARANOID >= 3
 182         Con_Print("D");
 183 #endif
 184         return HULLCHECKSTATE_DONE;
 185 }
 186
 187 #if 0
 188 // used if start and end are the same
 189 static void RecursiveHullCheckPoint (RecursiveHullCheckTraceInfo_t *t, int num)
 190 {
 191         // If you can read this, you understand BSP trees
 192         while (num >= 0)
 193                 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];
 194
 195         // check for empty
 196         t->trace->endcontents = num;
 197         if (t->trace->thiscontents)
 198         {
 199                 if (num == t->trace->thiscontents)
 200                         t->trace->allsolid = false;
 201                 else
 202                 {
 203                         // if the first leaf is solid, set startsolid
 204                         if (t->trace->allsolid)
 205                                 t->trace->startsolid = true;
 206                 }
 207         }
 208         else
 209         {
 210                 if (num != CONTENTS_SOLID)
 211                 {
 212                         t->trace->allsolid = false;
 213                         if (num == CONTENTS_EMPTY)
 214                                 t->trace->inopen = true;
 215                         else
 216                                 t->trace->inwater = true;
 217                 }
 218                 else
 219                 {
 220                         // if the first leaf is solid, set startsolid
 221                         if (t->trace->allsolid)
 222                                 t->trace->startsolid = true;
 223                 }
 224         }
 225 }
 226 #endif
 227
 228 static hull_t box_hull;
 229 static dclipnode_t box_clipnodes[6];
 230 static mplane_t box_planes[6];
 231
 232 void Mod_Q1BSP_Collision_Init (void)
 233 {
 234         int             i;
 235         int             side;
 236
 237         //Set up the planes and clipnodes so that the six floats of a bounding box
 238         //can just be stored out and get a proper hull_t structure.
 239
 240         box_hull.clipnodes = box_clipnodes;
 241         box_hull.planes = box_planes;
 242         box_hull.firstclipnode = 0;
 243         box_hull.lastclipnode = 5;
 244
 245         for (i = 0;i < 6;i++)
 246         {
 247                 box_clipnodes[i].planenum = i;
 248
 249                 side = i&1;
 250
 251                 box_clipnodes[i].children[side] = CONTENTS_EMPTY;
 252                 if (i != 5)
 253                         box_clipnodes[i].children[side^1] = i + 1;
 254                 else
 255                         box_clipnodes[i].children[side^1] = CONTENTS_SOLID;
 256
 257                 box_planes[i].type = i>>1;
 258                 box_planes[i].normal[i>>1] = 1;
 259         }
 260 }
 261
 262 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, int hitsupercontentsmask, int boxsupercontents)
 263 {
 264         RecursiveHullCheckTraceInfo_t rhc;
 265         // fill in a default trace
 266         memset(&rhc, 0, sizeof(rhc));
 267         memset(trace, 0, sizeof(trace_t));
 268         //To keep everything totally uniform, bounding boxes are turned into small
 269         //BSP trees instead of being compared directly.
 270         // create a temp hull from bounding box sizes
 271         box_planes[0].dist = cmaxs[0] - mins[0];
 272         box_planes[1].dist = cmins[0] - maxs[0];
 273         box_planes[2].dist = cmaxs[1] - mins[1];
 274         box_planes[3].dist = cmins[1] - maxs[1];
 275         box_planes[4].dist = cmaxs[2] - mins[2];
 276         box_planes[5].dist = cmins[2] - maxs[2];
 277         // trace a line through the generated clipping hull
 278         rhc.boxsupercontents = boxsupercontents;
 279         rhc.hull = &box_hull;
 280         rhc.trace = trace;
 281         rhc.trace->hitsupercontentsmask = hitsupercontentsmask;
 282         rhc.trace->fraction = 1;
 283         rhc.trace->realfraction = 1;
 284         rhc.trace->allsolid = true;
 285         VectorCopy(start, rhc.start);
 286         VectorCopy(end, rhc.end);
 287         VectorSubtract(rhc.end, rhc.start, rhc.dist);
 288         Mod_Q1BSP_RecursiveHullCheck(&rhc, rhc.hull->firstclipnode, 0, 1, rhc.start, rhc.end);
 289         VectorMA(rhc.start, rhc.trace->fraction, rhc.dist, rhc.trace->endpos);
 290         if (rhc.trace->startsupercontents)
 291                 rhc.trace->startsupercontents = boxsupercontents;
 292 }
 293 #endif
 294
 295 void Collision_Init (void)
 296 {
 297         Cvar_RegisterVariable(&collision_impactnudge);
 298         Cvar_RegisterVariable(&collision_startnudge);
 299         Cvar_RegisterVariable(&collision_endnudge);
 300         Cvar_RegisterVariable(&collision_enternudge);
 301         Cvar_RegisterVariable(&collision_leavenudge);
 302 }
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317 void Collision_PrintBrushAsQHull(colbrushf_t *brush, const char *name)
 318 {
 319         int i;
 320         Con_Printf("3 %s\n%i\n", name, brush->numpoints);
 321         for (i = 0;i < brush->numpoints;i++)
 322                 Con_Printf("%f %f %f\n", brush->points[i].v[0], brush->points[i].v[1], brush->points[i].v[2]);
 323         // FIXME: optimize!
 324         Con_Printf("4\n%i\n", brush->numplanes);
 325         for (i = 0;i < brush->numplanes;i++)
 326                 Con_Printf("%f %f %f %f\n", brush->planes[i].normal[0], brush->planes[i].normal[1], brush->planes[i].normal[2], brush->planes[i].dist);
 327 }
 328
 329 void Collision_ValidateBrush(colbrushf_t *brush)
 330 {
 331         int j, k, pointsoffplanes, printbrush;
 332         float d;
 333         printbrush = false;
 334         if (!brush->numpoints)
 335         {
 336                 Con_Print("Collision_ValidateBrush: brush with no points!\n");
 337                 printbrush = true;
 338         }
 339 #if 0
 340         // it's ok for a brush to have one point and no planes...
 341         if (brush->numplanes == 0 && brush->numpoints != 1)
 342         {
 343                 Con_Print("Collision_ValidateBrush: brush with no planes and more than one point!\n");
 344                 printbrush = true;
 345         }
 346 #endif
 347         if (brush->numplanes)
 348         {
 349                 pointsoffplanes = 0;
 350                 for (k = 0;k < brush->numplanes;k++)
 351                 {
 352                         if (DotProduct(brush->planes[k].normal, brush->planes[k].normal) < 0.0001f)
 353                                 Con_Printf("Collision_ValidateBrush: plane #%i (%f %f %f %f) is degenerate\n", k, brush->planes[k].normal[0], brush->planes[k].normal[1], brush->planes[k].normal[2], brush->planes[k].dist);
 354                         for (j = 0;j < brush->numpoints;j++)
 355                         {
 356                                 d = DotProduct(brush->points[j].v, brush->planes[k].normal) - brush->planes[k].dist;
 357                                 if (d > (1.0f / 8.0f))
 358                                 {
 359                                         Con_Printf("Collision_ValidateBrush: point #%i (%f %f %f) infront of plane #%i (%f %f %f %f)\n", j, brush->points[j].v[0], brush->points[j].v[1], brush->points[j].v[2], k, brush->planes[k].normal[0], brush->planes[k].normal[1], brush->planes[k].normal[2], brush->planes[k].dist);
 360                                         printbrush = true;
 361                                 }
 362                                 if (fabs(d) > 0.01f)
 363                                         pointsoffplanes++;
 364                         }
 365                 }
 366                 if (pointsoffplanes == 0) // all points are on all planes
 367                 {
 368                         Con_Print("Collision_ValidateBrush: all points lie on all planes (degenerate, no brush volume!)\n");
 369                         printbrush = true;
 370                 }
 371         }
 372         if (printbrush)
 373                 Collision_PrintBrushAsQHull(brush, "unnamed");
 374 }
 375
 376 float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 377 {
 378         float dist, bestdist;
 379         bestdist = DotProduct(points->v, normal);
 380         points++;
 381         while(--numpoints)
 382         {
 383                 dist = DotProduct(points->v, normal);
 384                 bestdist = min(bestdist, dist);
 385                 points++;
 386         }
 387         return bestdist;
 388 }
 389
 390 float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 391 {
 392         float dist, bestdist;
 393         bestdist = DotProduct(points->v, normal);
 394         points++;
 395         while(--numpoints)
 396         {
 397                 dist = DotProduct(points->v, normal);
 398                 bestdist = max(bestdist, dist);
 399                 points++;
 400         }
 401         return bestdist;
 402 }
 403
 404
 405 colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const mplane_t *originalplanes, int supercontents, winding_t *temp1, winding_t *temp2)
 406 {
 407         int j, k, m;
 408         int numpoints, maxpoints, numplanes, maxplanes, numelements, maxelements, numtriangles, numpolypoints, maxpolypoints;
 409         winding_t *w, *temp, *othertemp;
 410         colbrushf_t *brush;
 411         colpointf_t pointsbuf[256];
 412         colplanef_t planesbuf[256];
 413         int elementsbuf[1024];
 414         int polypointbuf[256];
 415         // construct a collision brush (points, planes, and renderable mesh) from
 416         // a set of planes, this also optimizes out any unnecessary planes (ones
 417         // whose polygon is clipped away by the other planes)
 418         numpoints = 0;maxpoints = 256;
 419         numplanes = 0;maxplanes = 256;
 420         numelements = 0;maxelements = 1024;
 421         numtriangles = 0;
 422         maxpolypoints = 256;
 423         for (j = 0;j < numoriginalplanes;j++)
 424         {
 425                 // add the plane uniquely (no duplicates)
 426                 for (k = 0;k < numplanes;k++)
 427                         if (VectorCompare(planesbuf[k].normal, originalplanes[j].normal) && planesbuf[k].dist == originalplanes[j].dist)
 428                                 break;
 429                 // if the plane is a duplicate, skip it
 430                 if (k < numplanes)
 431                         continue;
 432                 // check if there are too many and skip the brush
 433                 if (numplanes >= 256)
 434                 {
 435                         Con_Print("Mod_Q3BSP_LoadBrushes: failed to build collision brush: too many planes for buffer\n");
 436                         return NULL;
 437                 }
 438
 439                 // create a large polygon from the plane
 440                 w = temp1;
 441                 othertemp = temp2;
 442                 BufWinding_NewFromPlane(w, originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist);
 443                 // clip it by all other planes
 444                 for (k = 0;k < numoriginalplanes && w->numpoints;k++)
 445                 {
 446                         if (k != j)
 447                         {
 448                                 // we want to keep the inside of the brush plane so we flip
 449                                 // the cutting plane
 450                                 BufWinding_Divide(w, -originalplanes[k].normal[0], -originalplanes[k].normal[1], -originalplanes[k].normal[2], -originalplanes[k].dist, othertemp, NULL, NULL, NULL);
 451                                 temp = w;
 452                                 w = othertemp;
 453                                 othertemp = temp;
 454                         }
 455                 }
 456                 // if nothing is left, skip it
 457                 if (!w->numpoints)
 458                         continue;
 459
 460                 // copy off the number of points for later when the winding is freed
 461                 numpolypoints = w->numpoints;
 462
 463                 // check if there are too many polygon vertices for buffer
 464                 if (numpolypoints > maxpolypoints)
 465                 {
 466                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 467                         return NULL;
 468                 }
 469
 470                 // check if there are too many triangle elements for buffer
 471                 if (numelements + (w->numpoints - 2) * 3 > maxelements)
 472                 {
 473                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
 474                         return NULL;
 475                 }
 476
 477                 for (k = 0;k < w->numpoints;k++)
 478                 {
 479                         // check if there is already a matching point (no duplicates)
 480                         for (m = 0;m < numpoints;m++)
 481                                 if (VectorDistance2(w->points[k], pointsbuf[m].v) < COLLISION_SNAP)
 482                                         break;
 483
 484                         // if there is no match, add a new one
 485                         if (m == numpoints)
 486                         {
 487                                 // check if there are too many and skip the brush
 488                                 if (numpoints >= 256)
 489                                 {
 490                                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 491                                         Winding_Free(w);
 492                                         return NULL;
 493                                 }
 494                                 // add the new one
 495                                 VectorCopy(w->points[k], pointsbuf[numpoints].v);
 496                                 numpoints++;
 497                         }
 498
 499                         // store the index into a buffer
 500                         polypointbuf[k] = m;
 501                 }
 502                 w = NULL;
 503                 othertemp = NULL;
 504                 temp = NULL;
 505
 506                 // add the triangles for the polygon
 507                 // (this particular code makes a triangle fan)
 508                 for (k = 0;k < numpolypoints - 2;k++)
 509                 {
 510                         numtriangles++;
 511                         elementsbuf[numelements++] = polypointbuf[0];
 512                         elementsbuf[numelements++] = polypointbuf[k + 1];
 513                         elementsbuf[numelements++] = polypointbuf[k + 2];
 514                 }
 515
 516                 // add the new plane
 517                 VectorCopy(originalplanes[j].normal, planesbuf[numplanes].normal);
 518                 planesbuf[numplanes].dist = originalplanes[j].dist;
 519                 numplanes++;
 520         }
 521
 522         // if nothing is left, there's nothing to allocate
 523         if (numtriangles < 4 || numplanes < 4 || numpoints < 4)
 524                 return NULL;
 525
 526         // allocate the brush and copy to it
 527         brush = Collision_AllocBrushFloat(mempool, numpoints, numplanes, numtriangles, supercontents);
 528         memcpy(brush->points, pointsbuf, numpoints * sizeof(colpointf_t));
 529         memcpy(brush->planes, planesbuf, numplanes * sizeof(colplanef_t));
 530         memcpy(brush->elements, elementsbuf, numtriangles * sizeof(int[3]));
 531         // recalc distances
 532         for (j = 0;j < brush->numplanes;j++)
 533                 brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
 534         VectorCopy(brush->points[0].v, brush->mins);
 535         VectorCopy(brush->points[0].v, brush->maxs);
 536         for (j = 1;j < brush->numpoints;j++)
 537         {
 538                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
 539                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
 540                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
 541                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
 542                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
 543                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
 544         }
 545         brush->mins[0] -= 1;
 546         brush->mins[1] -= 1;
 547         brush->mins[2] -= 1;
 548         brush->maxs[0] += 1;
 549         brush->maxs[1] += 1;
 550         brush->maxs[2] += 1;
 551         Collision_ValidateBrush(brush);
 552         return brush;
 553 }
 554
 555
 556
 557 colbrushf_t *Collision_AllocBrushFloat(mempool_t *mempool, int numpoints, int numplanes, int numtriangles, int supercontents)
 558 {
 559         colbrushf_t *brush;
 560         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpoints + sizeof(colplanef_t) * numplanes + sizeof(int[3]) * numtriangles);
 561         brush->supercontents = supercontents;
 562         brush->numplanes = numplanes;
 563         brush->numpoints = numpoints;
 564         brush->numtriangles = numtriangles;
 565         brush->planes = (void *)(brush + 1);
 566         brush->points = (void *)(brush->planes + brush->numplanes);
 567         brush->elements = (void *)(brush->points + brush->numpoints);
 568         return brush;
 569 }
 570
 571 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 572 {
 573         int i;
 574         float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist, temp[3];
 575         colpointf_t *p, *p2;
 576
 577         if (brush->numpoints == 3)
 578         {
 579                 // optimized triangle case
 580                 TriangleNormal(brush->points[0].v, brush->points[1].v, brush->points[2].v, brush->planes[0].normal);
 581                 if (DotProduct(brush->planes[0].normal, brush->planes[0].normal) < 0.0001f)
 582                 {
 583                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 584                         brush->numplanes = 0;
 585                         return;
 586                 }
 587                 else
 588                 {
 589                         brush->numplanes = 5;
 590                         VectorNormalize(brush->planes[0].normal);
 591                         brush->planes[0].dist = DotProduct(brush->points->v, brush->planes[0].normal);
 592                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 593                         brush->planes[1].dist = -brush->planes[0].dist;
 594                         VectorSubtract(brush->points[2].v, brush->points[0].v, edge0);
 595                         VectorSubtract(brush->points[0].v, brush->points[1].v, edge1);
 596                         VectorSubtract(brush->points[1].v, brush->points[2].v, edge2);
 597 #if 1
 598                         {
 599                                 float projectionnormal[3], projectionedge0[3], projectionedge1[3], projectionedge2[3];
 600                                 int i, best;
 601                                 float dist, bestdist;
 602                                 bestdist = fabs(brush->planes[0].normal[0]);
 603                                 best = 0;
 604                                 for (i = 1;i < 3;i++)
 605                                 {
 606                                         dist = fabs(brush->planes[0].normal[i]);
 607                                         if (bestdist < dist)
 608                                         {
 609                                                 bestdist = dist;
 610                                                 best = i;
 611                                         }
 612                                 }
 613                                 VectorClear(projectionnormal);
 614                                 if (brush->planes[0].normal[best] < 0)
 615                                         projectionnormal[best] = -1;
 616                                 else
 617                                         projectionnormal[best] = 1;
 618                                 VectorCopy(edge0, projectionedge0);
 619                                 VectorCopy(edge1, projectionedge1);
 620                                 VectorCopy(edge2, projectionedge2);
 621                                 projectionedge0[best] = 0;
 622                                 projectionedge1[best] = 0;
 623                                 projectionedge2[best] = 0;
 624                                 CrossProduct(projectionedge0, projectionnormal, brush->planes[2].normal);
 625                                 CrossProduct(projectionedge1, projectionnormal, brush->planes[3].normal);
 626                                 CrossProduct(projectionedge2, projectionnormal, brush->planes[4].normal);
 627                         }
 628 #else
 629                         CrossProduct(edge0, brush->planes->normal, brush->planes[2].normal);
 630                         CrossProduct(edge1, brush->planes->normal, brush->planes[3].normal);
 631                         CrossProduct(edge2, brush->planes->normal, brush->planes[4].normal);
 632 #endif
 633                         VectorNormalize(brush->planes[2].normal);
 634                         VectorNormalize(brush->planes[3].normal);
 635                         VectorNormalize(brush->planes[4].normal);
 636                         brush->planes[2].dist = DotProduct(brush->points[2].v, brush->planes[2].normal);
 637                         brush->planes[3].dist = DotProduct(brush->points[0].v, brush->planes[3].normal);
 638                         brush->planes[4].dist = DotProduct(brush->points[1].v, brush->planes[4].normal);
 639
 640                         if (developer.integer)
 641                         {
 642                                 // validation code
 643                                 VectorSubtract(brush->points[0].v, brush->points[1].v, edge0);
 644                                 VectorSubtract(brush->points[2].v, brush->points[1].v, edge1);
 645                                 CrossProduct(edge1, edge0, normal);
 646                                 VectorNormalize(normal);
 647                                 VectorSubtract(normal, brush->planes[0].normal, temp);
 648                                 if (VectorLength(temp) > 0.01f)
 649                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: TriangleNormal gave wrong answer (%f %f %f != correct answer %f %f %f)\n", brush->planes->normal[0], brush->planes->normal[1], brush->planes->normal[2], normal[0], normal[1], normal[2]);
 650                                 if (fabs(DotProduct(brush->planes[1].normal, brush->planes[0].normal) - -1.0f) > 0.01f || fabs(brush->planes[1].dist - -brush->planes[0].dist) > 0.01f)
 651                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 1 (%f %f %f %f) is not opposite plane 0 (%f %f %f %f)\n", brush->planes[1].normal[0], brush->planes[1].normal[1], brush->planes[1].normal[2], brush->planes[1].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[0].dist);
 652 #if 0
 653                                 if (fabs(DotProduct(brush->planes[2].normal, brush->planes[0].normal)) > 0.01f)
 654                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 2 (%f %f %f %f) is not perpendicular to plane 0 (%f %f %f %f)\n", brush->planes[2].normal[0], brush->planes[2].normal[1], brush->planes[2].normal[2], brush->planes[2].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[2].dist);
 655                                 if (fabs(DotProduct(brush->planes[3].normal, brush->planes[0].normal)) > 0.01f)
 656                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 3 (%f %f %f %f) is not perpendicular to plane 0 (%f %f %f %f)\n", brush->planes[3].normal[0], brush->planes[3].normal[1], brush->planes[3].normal[2], brush->planes[3].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[3].dist);
 657                                 if (fabs(DotProduct(brush->planes[4].normal, brush->planes[0].normal)) > 0.01f)
 658                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 4 (%f %f %f %f) is not perpendicular to plane 0 (%f %f %f %f)\n", brush->planes[4].normal[0], brush->planes[4].normal[1], brush->planes[4].normal[2], brush->planes[4].dist, brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[4].dist);
 659                                 if (fabs(DotProduct(brush->planes[2].normal, edge0)) > 0.01f)
 660                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 2 (%f %f %f %f) is not perpendicular to edge 0 (%f %f %f to %f %f %f)\n", brush->planes[2].normal[0], brush->planes[2].normal[1], brush->planes[2].normal[2], brush->planes[2].dist, brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2]);
 661                                 if (fabs(DotProduct(brush->planes[3].normal, edge1)) > 0.01f)
 662                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 3 (%f %f %f %f) is not perpendicular to edge 1 (%f %f %f to %f %f %f)\n", brush->planes[3].normal[0], brush->planes[3].normal[1], brush->planes[3].normal[2], brush->planes[3].dist, brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2]);
 663                                 if (fabs(DotProduct(brush->planes[4].normal, edge2)) > 0.01f)
 664                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: plane 4 (%f %f %f %f) is not perpendicular to edge 2 (%f %f %f to %f %f %f)\n", brush->planes[4].normal[0], brush->planes[4].normal[1], brush->planes[4].normal[2], brush->planes[4].dist, brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2]);
 665 #endif
 666                                 if (fabs(DotProduct(brush->points[0].v, brush->planes[0].normal) - brush->planes[0].dist) > 0.01f || fabs(DotProduct(brush->points[1].v, brush->planes[0].normal) - brush->planes[0].dist) > 0.01f || fabs(DotProduct(brush->points[2].v, brush->planes[0].normal) - brush->planes[0].dist) > 0.01f)
 667                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edges (%f %f %f to %f %f %f to %f %f %f) off front plane 0 (%f %f %f %f)\n", brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->planes[0].normal[0], brush->planes[0].normal[1], brush->planes[0].normal[2], brush->planes[0].dist);
 668                                 if (fabs(DotProduct(brush->points[0].v, brush->planes[1].normal) - brush->planes[1].dist) > 0.01f || fabs(DotProduct(brush->points[1].v, brush->planes[1].normal) - brush->planes[1].dist) > 0.01f || fabs(DotProduct(brush->points[2].v, brush->planes[1].normal) - brush->planes[1].dist) > 0.01f)
 669                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edges (%f %f %f to %f %f %f to %f %f %f) off back plane 1 (%f %f %f %f)\n", brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->planes[1].normal[0], brush->planes[1].normal[1], brush->planes[1].normal[2], brush->planes[1].dist);
 670                                 if (fabs(DotProduct(brush->points[2].v, brush->planes[2].normal) - brush->planes[2].dist) > 0.01f || fabs(DotProduct(brush->points[0].v, brush->planes[2].normal) - brush->planes[2].dist) > 0.01f)
 671                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edge 0 (%f %f %f to %f %f %f) off front plane 2 (%f %f %f %f)\n", brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->planes[2].normal[0], brush->planes[2].normal[1], brush->planes[2].normal[2], brush->planes[2].dist);
 672                                 if (fabs(DotProduct(brush->points[0].v, brush->planes[3].normal) - brush->planes[3].dist) > 0.01f || fabs(DotProduct(brush->points[1].v, brush->planes[3].normal) - brush->planes[3].dist) > 0.01f)
 673                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edge 0 (%f %f %f to %f %f %f) off front plane 2 (%f %f %f %f)\n", brush->points[0].v[0], brush->points[0].v[1], brush->points[0].v[2], brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->planes[3].normal[0], brush->planes[3].normal[1], brush->planes[3].normal[2], brush->planes[3].dist);
 674                                 if (fabs(DotProduct(brush->points[1].v, brush->planes[4].normal) - brush->planes[4].dist) > 0.01f || fabs(DotProduct(brush->points[2].v, brush->planes[4].normal) - brush->planes[4].dist) > 0.01f)
 675                                         Con_Printf("Collision_CalcPlanesForPolygonBrushFloat: edge 0 (%f %f %f to %f %f %f) off front plane 2 (%f %f %f %f)\n", brush->points[1].v[0], brush->points[1].v[1], brush->points[1].v[2], brush->points[2].v[0], brush->points[2].v[1], brush->points[2].v[2], brush->planes[4].normal[0], brush->planes[4].normal[1], brush->planes[4].normal[2], brush->planes[4].dist);
 676                         }
 677                 }
 678         }
 679         else
 680         {
 681                 // choose best surface normal for polygon's plane
 682                 bestdist = 0;
 683                 for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
 684                 {
 685                         VectorSubtract(p[-1].v, p[0].v, edge0);
 686                         VectorSubtract(p[1].v, p[0].v, edge1);
 687                         CrossProduct(edge0, edge1, normal);
 688                         //TriangleNormal(p[-1].v, p[0].v, p[1].v, normal);
 689                         dist = DotProduct(normal, normal);
 690                         if (i == 0 || bestdist < dist)
 691                         {
 692                                 bestdist = dist;
 693                                 VectorCopy(normal, brush->planes->normal);
 694                         }
 695                 }
 696                 if (bestdist < 0.0001f)
 697                 {
 698                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 699                         brush->numplanes = 0;
 700                         return;
 701                 }
 702                 else
 703                 {
 704                         brush->numplanes = brush->numpoints + 2;
 705                         VectorNormalize(brush->planes->normal);
 706                         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 707
 708                         // negate plane to create other side
 709                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 710                         brush->planes[1].dist = -brush->planes[0].dist;
 711                         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
 712                         {
 713                                 VectorSubtract(p->v, p2->v, edge0);
 714                                 CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
 715                                 VectorNormalize(brush->planes[i + 2].normal);
 716                                 brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
 717                         }
 718                 }
 719         }
 720
 721         if (developer.integer)
 722         {
 723                 // validity check - will be disabled later
 724                 Collision_ValidateBrush(brush);
 725                 for (i = 0;i < brush->numplanes;i++)
 726                 {
 727                         int j;
 728                         for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 729                                 if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + (1.0 / 32.0))
 730                                         Con_Printf("Error in brush plane generation, plane %i\n", i);
 731                 }
 732         }
 733 }
 734
 735 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents)
 736 {
 737         colbrushf_t *brush;
 738         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
 739         brush->supercontents = supercontents;
 740         brush->numpoints = numpoints;
 741         brush->numplanes = numpoints + 2;
 742         brush->planes = (void *)(brush + 1);
 743         brush->points = (colpointf_t *)points;
 744         Host_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...\n");
 745         return brush;
 746 }
 747
 748 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 749 void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
 750 {
 751         int nplane, nplane2, fstartsolid, fendsolid, brushsolid;
 752         float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
 753         const colplanef_t *startplane, *endplane;
 754
 755         enterfrac = -1;
 756         enterfrac2 = -1;
 757         leavefrac = 1;
 758         fstartsolid = true;
 759         fendsolid = true;
 760
 761         for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
 762         {
 763                 nplane2 = nplane;
 764                 if (nplane2 >= thatbrush_start->numplanes)
 765                 {
 766                         nplane2 -= thatbrush_start->numplanes;
 767                         startplane = thisbrush_start->planes + nplane2;
 768                         endplane = thisbrush_end->planes + nplane2;
 769                         if (developer.integer)
 770                         {
 771                                 // any brush with degenerate planes is not worth handling
 772                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 773                                 {
 774                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thisbrush plane!\n");
 775                                         return;
 776                                 }
 777                                 f = furthestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints);
 778                                 if (fabs(f - startplane->dist) > 0.01f)
 779                                         Con_Printf("startplane->dist %f != calculated %f (thisbrush_start)\n", startplane->dist, f);
 780                         }
 781                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints) - collision_startnudge.value;
 782                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - collision_endnudge.value;
 783                 }
 784                 else
 785                 {
 786                         startplane = thatbrush_start->planes + nplane2;
 787                         endplane = thatbrush_end->planes + nplane2;
 788                         if (developer.integer)
 789                         {
 790                                 // any brush with degenerate planes is not worth handling
 791                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 792                                 {
 793                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thatbrush plane!\n");
 794                                         return;
 795                                 }
 796                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 797                                 if (fabs(f - startplane->dist) > 0.01f)
 798                                         Con_Printf("startplane->dist %f != calculated %f (thatbrush_start)\n", startplane->dist, f);
 799                         }
 800                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - startplane->dist - collision_startnudge.value;
 801                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - endplane->dist - collision_endnudge.value;
 802                 }
 803                 //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 804
 805                 move = d1 - d2;
 806                 if (move > 0)
 807                 {
 808                         // moving into brush
 809                         if (d2 > collision_enternudge.value)
 810                                 return;
 811                         if (d1 < 0)
 812                                 continue;
 813                         // enter
 814                         fstartsolid = false;
 815                         imove = 1 / move;
 816                         f = (d1 - collision_enternudge.value) * imove;
 817                         f = bound(0, f, 1);
 818                         if (enterfrac < f)
 819                         {
 820                                 enterfrac = f;
 821                                 enterfrac2 = f - collision_impactnudge.value * imove;
 822                                 enterfrac2 = bound(0, enterfrac2, 1);
 823                                 VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 824                         }
 825                 }
 826                 else if (move < 0)
 827                 {
 828                         // moving out of brush
 829                         if (d1 > collision_leavenudge.value)
 830                                 return;
 831                         if (d2 < 0)
 832                                 continue;
 833                         // leave
 834                         fendsolid = false;
 835                         f = (d1 + collision_leavenudge.value) / move;
 836                         f = bound(0, f, 1);
 837                         if (leavefrac > f)
 838                                 leavefrac = f;
 839                 }
 840                 else
 841                 {
 842                         // sliding along plane
 843                         if (d1 > 0)
 844                                 return;
 845                 }
 846         }
 847
 848         brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
 849         if (fstartsolid)
 850         {
 851                 trace->startsupercontents |= thatbrush_start->supercontents;
 852                 if (brushsolid)
 853                 {
 854                         trace->startsolid = true;
 855                         if (fendsolid)
 856                                 trace->allsolid = true;
 857                 }
 858         }
 859
 860         // LordHavoc: we need an epsilon nudge here because for a point trace the
 861         // penetrating line segment is normally zero length if this brush was
 862         // generated from a polygon (infinitely thin), and could even be slightly
 863         // positive or negative due to rounding errors in that case.
 864         if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
 865         {
 866 #if 0
 867                 // broken
 868                 if (thatbrush_start->ispolygon)
 869                 {
 870                         d1 = nearestplanedist_float(thatbrush_start->planes[0].normal, thisbrush_start->points, thisbrush_start->numpoints) - thatbrush_start->planes[0].dist - collision_startnudge.value;
 871                         d2 = nearestplanedist_float(thatbrush_end->planes[0].normal, thisbrush_end->points, thisbrush_end->numpoints) - thatbrush_end->planes[0].dist - collision_endnudge.value;
 872                         move = d1 - d2;
 873                         if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
 874                                 return;
 875                         // enter
 876                         imove = 1 / move;
 877                         enterfrac = (d1 - collision_enternudge.value) * imove;
 878                         if (enterfrac < trace->realfraction)
 879                         {
 880                                 enterfrac2 = enterfrac - collision_impactnudge.value * imove;
 881                                 trace->realfraction = bound(0, enterfrac, 1);
 882                                 trace->fraction = bound(0, enterfrac2, 1);
 883                                 VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
 884                         }
 885                 }
 886                 else
 887 #endif
 888                 {
 889                         trace->realfraction = bound(0, enterfrac, 1);
 890                         trace->fraction = bound(0, enterfrac2, 1);
 891                         VectorCopy(newimpactnormal, trace->plane.normal);
 892                 }
 893         }
 894 }
 895
 896 // NOTE: start and end brush pair must have same numplanes/numpoints
 897 void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
 898 {
 899         int nplane, fstartsolid, fendsolid, brushsolid;
 900         float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
 901         const colplanef_t *startplane, *endplane;
 902
 903         enterfrac = -1;
 904         enterfrac2 = -1;
 905         leavefrac = 1;
 906         fstartsolid = true;
 907         fendsolid = true;
 908
 909         for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
 910         {
 911                 startplane = thatbrush_start->planes + nplane;
 912                 endplane = thatbrush_end->planes + nplane;
 913                 d1 = DotProduct(startplane->normal, linestart) - startplane->dist - collision_startnudge.value;
 914                 d2 = DotProduct(endplane->normal, lineend) - endplane->dist - collision_endnudge.value;
 915                 if (developer.integer)
 916                 {
 917                         // any brush with degenerate planes is not worth handling
 918                         if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 919                         {
 920                                 Con_Print("Collision_TraceLineBrushFloat: degenerate plane!\n");
 921                                 return;
 922                         }
 923                         if (thatbrush_start->numpoints)
 924                         {
 925                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 926                                 if (fabs(f - startplane->dist) > 0.01f)
 927                                         Con_Printf("startplane->dist %f != calculated %f\n", startplane->dist, f);
 928                         }
 929                 }
 930
 931                 move = d1 - d2;
 932                 if (move > 0)
 933                 {
 934                         // moving into brush
 935                         if (d2 >= 0)
 936                                 return;
 937                         if (d1 <= 0)
 938                                 continue;
 939                         // enter
 940                         fstartsolid = false;
 941                         imove = 1 / move;
 942                         f = (d1 - collision_enternudge.value) * imove;
 943                         if (enterfrac < f)
 944                         {
 945                                 enterfrac = f;
 946                                 enterfrac2 = f - collision_impactnudge.value * imove;
 947                                 VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 948                         }
 949                 }
 950                 else
 951                 {
 952                         // moving out of brush
 953                         if (d1 >= 0)
 954                                 return;
 955                         if (d2 <= 0)
 956                                 continue;
 957                         // leave
 958                         fendsolid = false;
 959                         f = (d1 - collision_leavenudge.value) / move;
 960                         if (leavefrac > f)
 961                                 leavefrac = f;
 962                 }
 963         }
 964
 965         brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
 966         if (fstartsolid)
 967         {
 968                 trace->startsupercontents |= thatbrush_start->supercontents;
 969                 if (brushsolid)
 970                 {
 971                         trace->startsolid = true;
 972                         if (fendsolid)
 973                                 trace->allsolid = true;
 974                 }
 975         }
 976
 977         // LordHavoc: we need an epsilon nudge here because for a point trace the
 978         // penetrating line segment is normally zero length if this brush was
 979         // generated from a polygon (infinitely thin), and could even be slightly
 980         // positive or negative due to rounding errors in that case.
 981         if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
 982         {
 983 #if 0
 984                 // broken
 985                 if (thatbrush_start->ispolygon)
 986                 {
 987                         d1 = DotProduct(thatbrush_start->planes[0].normal, linestart) - thatbrush_start->planes[0].dist - collision_startnudge.value;
 988                         d2 = DotProduct(thatbrush_end->planes[0].normal, lineend) - thatbrush_end->planes[0].dist - collision_endnudge.value;
 989                         move = d1 - d2;
 990                         if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
 991                                 return;
 992                         // enter
 993                         imove = 1 / move;
 994                         enterfrac = (d1 - collision_enternudge.value) * imove;
 995                         if (enterfrac < trace->realfraction)
 996                         {
 997                                 enterfrac2 = enterfrac - collision_impactnudge.value * imove;
 998                                 trace->realfraction = bound(0, enterfrac, 1);
 999                                 trace->fraction = bound(0, enterfrac2, 1);
1000                                 VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
1001                         }
1002                 }
1003                 else
1004 #endif
1005                 {
1006                         trace->realfraction = bound(0, enterfrac, 1);
1007                         trace->fraction = bound(0, enterfrac2, 1);
1008                         VectorCopy(newimpactnormal, trace->plane.normal);
1009                 }
1010         }
1011 }
1012
1013 void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
1014 {
1015         int nplane;
1016         const colplanef_t *plane;
1017
1018         for (nplane = 0, plane = thatbrush->planes;nplane < thatbrush->numplanes;nplane++, plane++)
1019                 if (DotProduct(plane->normal, point) > plane->dist)
1020                         return;
1021
1022         trace->startsupercontents |= thatbrush->supercontents;
1023         if (trace->hitsupercontentsmask & thatbrush->supercontents)
1024         {
1025                 trace->startsolid = true;
1026                 trace->allsolid = true;
1027         }
1028 }
1029
1030 static colpointf_t polyf_points[256];
1031 static colplanef_t polyf_planes[256 + 2];
1032 static colbrushf_t polyf_brush;
1033
1034 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
1035 {
1036         while (numpoints--)
1037         {
1038                 out->v[0] = floor(in->v[0] * fractionprecision + 0.5f) * invfractionprecision;
1039                 out->v[1] = floor(in->v[1] * fractionprecision + 0.5f) * invfractionprecision;
1040                 out->v[2] = floor(in->v[2] * fractionprecision + 0.5f) * invfractionprecision;
1041         }
1042 }
1043
1044 void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, int supercontents)
1045 {
1046         if (numpoints > 256)
1047         {
1048                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1049                 return;
1050         }
1051         polyf_brush.numpoints = numpoints;
1052         polyf_brush.numplanes = numpoints + 2;
1053         //polyf_brush.points = (colpointf_t *)points;
1054         polyf_brush.planes = polyf_planes;
1055         polyf_brush.supercontents = supercontents;
1056         polyf_brush.points = polyf_points;
1057         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1058         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1059         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1060         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
1061 }
1062
1063 void Collision_TraceBrushTriangleMeshFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numtriangles, const int *element3i, const float *vertex3f, int supercontents, const vec3_t segmentmins, const vec3_t segmentmaxs)
1064 {
1065         int i;
1066         float facemins[3], facemaxs[3];
1067         polyf_brush.numpoints = 3;
1068         polyf_brush.numplanes = 5;
1069         polyf_brush.points = polyf_points;
1070         polyf_brush.planes = polyf_planes;
1071         polyf_brush.supercontents = supercontents;
1072         for (i = 0;i < numtriangles;i++, element3i += 3)
1073         {
1074                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
1075                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
1076                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
1077                 Collision_SnapCopyPoints(3, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1078                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0])) - 1;
1079                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
1080                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
1081                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
1082                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
1083                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
1084                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
1085                 {
1086                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1087                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1088                         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
1089                 }
1090         }
1091 }
1092
1093 void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numpoints, const float *points, int supercontents)
1094 {
1095         if (numpoints > 256)
1096         {
1097                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1098                 return;
1099         }
1100         polyf_brush.numpoints = numpoints;
1101         polyf_brush.numplanes = numpoints + 2;
1102         //polyf_brush.points = (colpointf_t *)points;
1103         polyf_brush.points = polyf_points;
1104         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1105         polyf_brush.planes = polyf_planes;
1106         polyf_brush.supercontents = supercontents;
1107         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1108         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1109         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
1110 }
1111
1112 void Collision_TraceLineTriangleMeshFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numtriangles, const int *element3i, const float *vertex3f, int supercontents, const vec3_t segmentmins, const vec3_t segmentmaxs)
1113 {
1114         int i;
1115 #if 1
1116         // FIXME: snap vertices?
1117         for (i = 0;i < numtriangles;i++, element3i += 3)
1118                 Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3);
1119 #else
1120         polyf_brush.numpoints = 3;
1121         polyf_brush.numplanes = 5;
1122         polyf_brush.points = polyf_points;
1123         polyf_brush.planes = polyf_planes;
1124         polyf_brush.supercontents = supercontents;
1125         for (i = 0;i < numtriangles;i++, element3i += 3)
1126         {
1127                 float facemins[3], facemaxs[3];
1128                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
1129                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
1130                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
1131                 Collision_SnapCopyPoints(numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1132                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0])) - 1;
1133                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
1134                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
1135                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
1136                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
1137                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
1138                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
1139                 {
1140                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1141                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1142                         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
1143                 }
1144         }
1145 #endif
1146 }
1147
1148
1149 static colpointf_t polyf_pointsstart[256], polyf_pointsend[256];
1150 static colplanef_t polyf_planesstart[256 + 2], polyf_planesend[256 + 2];
1151 static colbrushf_t polyf_brushstart, polyf_brushend;
1152
1153 void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, const matrix4x4_t *polygonmatrixstart, const matrix4x4_t *polygonmatrixend, int supercontents)
1154 {
1155         int i;
1156         if (numpoints > 256)
1157         {
1158                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1159                 return;
1160         }
1161         polyf_brushstart.numpoints = numpoints;
1162         polyf_brushstart.numplanes = numpoints + 2;
1163         polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
1164         polyf_brushstart.planes = polyf_planesstart;
1165         polyf_brushstart.supercontents = supercontents;
1166         for (i = 0;i < numpoints;i++)
1167                 Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
1168         polyf_brushend.numpoints = numpoints;
1169         polyf_brushend.numplanes = numpoints + 2;
1170         polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
1171         polyf_brushend.planes = polyf_planesend;
1172         polyf_brushend.supercontents = supercontents;
1173         for (i = 0;i < numpoints;i++)
1174                 Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
1175         Collision_SnapCopyPoints(numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
1176         Collision_SnapCopyPoints(numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
1177         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
1178         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
1179
1180         //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
1181         //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
1182
1183         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend);
1184 }
1185
1186
1187
1188 #define MAX_BRUSHFORBOX 16
1189 static int brushforbox_index = 0;
1190 static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
1191 static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
1192 static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
1193 static colbrushf_t brushforpoint_brush[MAX_BRUSHFORBOX];
1194
1195 void Collision_InitBrushForBox(void)
1196 {
1197         int i;
1198         for (i = 0;i < MAX_BRUSHFORBOX;i++)
1199         {
1200                 brushforbox_brush[i].supercontents = SUPERCONTENTS_SOLID;
1201                 brushforbox_brush[i].numpoints = 8;
1202                 brushforbox_brush[i].numplanes = 6;
1203                 brushforbox_brush[i].points = brushforbox_point + i * 8;
1204                 brushforbox_brush[i].planes = brushforbox_plane + i * 6;
1205                 brushforpoint_brush[i].supercontents = SUPERCONTENTS_SOLID;
1206                 brushforpoint_brush[i].numpoints = 1;
1207                 brushforpoint_brush[i].numplanes = 0;
1208                 brushforpoint_brush[i].points = brushforbox_point + i * 8;
1209                 brushforpoint_brush[i].planes = brushforbox_plane + i * 6;
1210         }
1211 }
1212
1213 colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs)
1214 {
1215         int i, j;
1216         vec3_t v;
1217         colbrushf_t *brush;
1218         if (brushforbox_brush[0].numpoints == 0)
1219                 Collision_InitBrushForBox();
1220         if (VectorCompare(mins, maxs))
1221         {
1222                 // point brush
1223                 brush = brushforpoint_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1224                 VectorCopy(mins, brush->points->v);
1225         }
1226         else
1227         {
1228                 brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1229                 // FIXME: optimize
1230                 for (i = 0;i < 8;i++)
1231                 {
1232                         v[0] = i & 1 ? maxs[0] : mins[0];
1233                         v[1] = i & 2 ? maxs[1] : mins[1];
1234                         v[2] = i & 4 ? maxs[2] : mins[2];
1235                         Matrix4x4_Transform(matrix, v, brush->points[i].v);
1236                 }
1237                 // FIXME: optimize!
1238                 for (i = 0;i < 6;i++)
1239                 {
1240                         VectorClear(v);
1241                         v[i >> 1] = i & 1 ? 1 : -1;
1242                         Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
1243                         VectorNormalize(brush->planes[i].normal);
1244                 }
1245         }
1246         for (j = 0;j < brush->numplanes;j++)
1247                 brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
1248         VectorCopy(brush->points[0].v, brush->mins);
1249         VectorCopy(brush->points[0].v, brush->maxs);
1250         for (j = 1;j < brush->numpoints;j++)
1251         {
1252                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
1253                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
1254                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
1255                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
1256                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
1257                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
1258         }
1259         brush->mins[0] -= 1;
1260         brush->mins[1] -= 1;
1261         brush->mins[2] -= 1;
1262         brush->maxs[0] += 1;
1263         brush->maxs[1] += 1;
1264         brush->maxs[2] += 1;
1265         Collision_ValidateBrush(brush);
1266         return brush;
1267 }
1268
1269 void Collision_ClipTrace_BrushBox(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, int hitsupercontentsmask)
1270 {
1271         colbrushf_t *boxbrush, *thisbrush_start, *thisbrush_end;
1272         matrix4x4_t identitymatrix;
1273         vec3_t startmins, startmaxs, endmins, endmaxs;
1274
1275         // create brushes for the collision
1276         VectorAdd(start, mins, startmins);
1277         VectorAdd(start, maxs, startmaxs);
1278         VectorAdd(end, mins, endmins);
1279         VectorAdd(end, maxs, endmaxs);
1280         Matrix4x4_CreateIdentity(&identitymatrix);
1281         boxbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs);
1282         thisbrush_start = Collision_BrushForBox(&identitymatrix, startmins, startmaxs);
1283         thisbrush_end = Collision_BrushForBox(&identitymatrix, endmins, endmaxs);
1284
1285         memset(trace, 0, sizeof(trace_t));
1286         trace->hitsupercontentsmask = hitsupercontentsmask;
1287         trace->fraction = 1;
1288         trace->realfraction = 1;
1289         trace->allsolid = true;
1290         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, boxbrush, boxbrush);
1291 }
1292
1293 // LordHavoc: currently unused and not yet tested
1294 // note: this can be used for tracing a moving sphere vs a stationary sphere,
1295 // by simply adding the moving sphere's radius to the sphereradius parameter,
1296 // all the results are correct (impactpoint, impactnormal, and fraction)
1297 float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
1298 {
1299         double dir[3], scale, v[3], deviationdist, impactdist, linelength;
1300         // make sure the impactpoint and impactnormal are valid even if there is
1301         // no collision
1302         impactpoint[0] = lineend[0];
1303         impactpoint[1] = lineend[1];
1304         impactpoint[2] = lineend[2];
1305         impactnormal[0] = 0;
1306         impactnormal[1] = 0;
1307         impactnormal[2] = 0;
1308         // calculate line direction
1309         dir[0] = lineend[0] - linestart[0];
1310         dir[1] = lineend[1] - linestart[1];
1311         dir[2] = lineend[2] - linestart[2];
1312         // normalize direction
1313         linelength = sqrt(dir[0] * dir[0] + dir[1] * dir[1] + dir[2] * dir[2]);
1314         if (linelength)
1315         {
1316                 scale = 1.0 / linelength;
1317                 dir[0] *= scale;
1318                 dir[1] *= scale;
1319                 dir[2] *= scale;
1320         }
1321         // this dotproduct calculates the distance along the line at which the
1322         // sphere origin is (nearest point to the sphere origin on the line)
1323         impactdist = dir[0] * (sphereorigin[0] - linestart[0]) + dir[1] * (sphereorigin[1] - linestart[1]) + dir[2] * (sphereorigin[2] - linestart[2]);
1324         // calculate point on line at that distance, and subtract the
1325         // sphereorigin from it, so we have a vector to measure for the distance
1326         // of the line from the sphereorigin (deviation, how off-center it is)
1327         v[0] = linestart[0] + impactdist * dir[0] - sphereorigin[0];
1328         v[1] = linestart[1] + impactdist * dir[1] - sphereorigin[1];
1329         v[2] = linestart[2] + impactdist * dir[2] - sphereorigin[2];
1330         deviationdist = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
1331         // if outside the radius, it's a miss for sure
1332         // (we do this comparison using squared radius to avoid a sqrt)
1333         if (deviationdist > sphereradius*sphereradius)
1334                 return 1; // miss (off to the side)
1335         // nudge back to find the correct impact distance
1336         impactdist += (sqrt(deviationdist) - sphereradius);
1337         if (impactdist >= linelength)
1338                 return 1; // miss (not close enough)
1339         if (impactdist < 0)
1340                 return 1; // miss (linestart is past or inside sphere)
1341         // calculate new impactpoint
1342         impactpoint[0] = linestart[0] + impactdist * dir[0];
1343         impactpoint[1] = linestart[1] + impactdist * dir[1];
1344         impactpoint[2] = linestart[2] + impactdist * dir[2];
1345         // calculate impactnormal (surface normal at point of impact)
1346         impactnormal[0] = impactpoint[0] - sphereorigin[0];
1347         impactnormal[1] = impactpoint[1] - sphereorigin[1];
1348         impactnormal[2] = impactpoint[2] - sphereorigin[2];
1349         // normalize impactnormal
1350         scale = impactnormal[0] * impactnormal[0] + impactnormal[1] * impactnormal[1] + impactnormal[2] * impactnormal[2];
1351         if (scale)
1352         {
1353                 scale = 1.0 / sqrt(scale);
1354                 impactnormal[0] *= scale;
1355                 impactnormal[1] *= scale;
1356                 impactnormal[2] *= scale;
1357         }
1358         // return fraction of movement distance
1359         return impactdist / linelength;
1360 }
1361
1362 void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2)
1363 {
1364         float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
1365
1366         // this code is designed for clockwise triangles, conversion to
1367         // counterclockwise would require swapping some things around...
1368         // it is easier to simply swap the point0 and point2 parameters to this
1369         // function when calling it than it is to rewire the internals.
1370
1371         // calculate the faceplanenormal of the triangle, this represents the front side
1372         TriangleNormal(point0, point1, point2, faceplanenormal);
1373         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
1374         if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
1375                 return;
1376         // normalize the normal
1377         VectorNormalize(faceplanenormal);
1378         // calculate the distance
1379         faceplanedist = DotProduct(point0, faceplanenormal);
1380
1381         // calculate the start distance
1382         d1 = DotProduct(faceplanenormal, linestart) - faceplanedist;
1383         // if start point is on the back side there is no collision
1384         // (we don't care about traces going through the triangle the wrong way)
1385         if (d1 < 0)
1386                 return;
1387
1388         // calculate the end distance
1389         d2 = DotProduct(faceplanenormal, lineend) - faceplanedist;
1390         // if both are in front, there is no collision
1391         if (d2 >= 0)
1392                 return;
1393
1394         // from here on we know d1 is >= 0 and d2 is < 0
1395         // this means the line starts infront and ends behind, passing through it
1396
1397         // calculate the recipricol of the distance delta,
1398         // so we can use it multiple times cheaply (instead of division)
1399         d = 1.0f / (d1 - d2);
1400         // calculate the impact fraction by taking the start distance (> 0)
1401         // and subtracting the face plane distance (this is the distance of the
1402         // triangle along that same normal)
1403         // then multiply by the recipricol distance delta
1404         f = d1 * d;
1405         // skip out if this impact is further away than previous ones
1406         if (f > trace->realfraction)
1407                 return;
1408         // calculate the perfect impact point for classification of insidedness
1409         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1410         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1411         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1412
1413         // calculate the edge normal and reject if impact is outside triangle
1414         // (an edge normal faces away from the triangle, to get the desired normal
1415         //  a crossproduct with the faceplanenormal is used, and because of the way
1416         // the insidedness comparison is written it does not need to be normalized)
1417
1418         VectorSubtract(point2, point0, edge);
1419         CrossProduct(edge, faceplanenormal, edgenormal);
1420         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1421                 return;
1422
1423         VectorSubtract(point0, point1, edge);
1424         CrossProduct(edge, faceplanenormal, edgenormal);
1425         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1426                 return;
1427
1428         VectorSubtract(point1, point2, edge);
1429         CrossProduct(edge, faceplanenormal, edgenormal);
1430         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1431                 return;
1432
1433         // store the new trace fraction
1434         trace->realfraction = bound(0, f, 1);
1435
1436         // calculate a nudged fraction to keep it out of the surface
1437         // (the main fraction remains perfect)
1438         fnudged = (d1 - collision_impactnudge.value) * d;
1439         trace->fraction = bound(0, fnudged, 1);
1440
1441         // store the new trace endpos
1442         // not needed, it's calculated later when the trace is finished
1443         //trace->endpos[0] = linestart[0] + fnudged * (lineend[0] - linestart[0]);
1444         //trace->endpos[1] = linestart[1] + fnudged * (lineend[1] - linestart[1]);
1445         //trace->endpos[2] = linestart[2] + fnudged * (lineend[2] - linestart[2]);
1446
1447         // store the new trace plane (because collisions only happen from
1448         // the front this is always simply the triangle normal, never flipped)
1449         VectorCopy(faceplanenormal, trace->plane.normal);
1450         trace->plane.dist = faceplanedist;
1451 }
1452
1453 typedef struct colbspnode_s
1454 {
1455         mplane_t plane;
1456         struct colbspnode_s *children[2];
1457         // the node is reallocated or split if max is reached
1458         int numcolbrushf;
1459         int maxcolbrushf;
1460         colbrushf_t **colbrushflist;
1461         //int numcolbrushd;
1462         //int maxcolbrushd;
1463         //colbrushd_t **colbrushdlist;
1464 }
1465 colbspnode_t;
1466
1467 typedef struct colbsp_s
1468 {
1469         mempool_t *mempool;
1470         colbspnode_t *nodes;
1471 }
1472 colbsp_t;
1473
1474 colbsp_t *Collision_CreateCollisionBSP(mempool_t *mempool)
1475 {
1476         colbsp_t *bsp;
1477         bsp = Mem_Alloc(mempool, sizeof(colbsp_t));
1478         bsp->mempool = mempool;
1479         bsp->nodes = Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
1480         return bsp;
1481 }
1482
1483 void Collision_FreeCollisionBSPNode(colbspnode_t *node)
1484 {
1485         if (node->children[0])
1486                 Collision_FreeCollisionBSPNode(node->children[0]);
1487         if (node->children[1])
1488                 Collision_FreeCollisionBSPNode(node->children[1]);
1489         while (--node->numcolbrushf)
1490                 Mem_Free(node->colbrushflist[node->numcolbrushf]);
1491         //while (--node->numcolbrushd)
1492         //      Mem_Free(node->colbrushdlist[node->numcolbrushd]);
1493         Mem_Free(node);
1494 }
1495
1496 void Collision_FreeCollisionBSP(colbsp_t *bsp)
1497 {
1498         Collision_FreeCollisionBSPNode(bsp->nodes);
1499         Mem_Free(bsp);
1500 }
1501
1502 void Collision_BoundingBoxOfBrushTraceSegment(const colbrushf_t *start, const colbrushf_t *end, vec3_t mins, vec3_t maxs, float startfrac, float endfrac)
1503 {
1504         int i;
1505         colpointf_t *ps, *pe;
1506         float tempstart[3], tempend[3];
1507         VectorLerp(start->points[0].v, startfrac, end->points[0].v, mins);
1508         VectorCopy(mins, maxs);
1509         for (i = 0, ps = start->points, pe = end->points;i < start->numpoints;i++, ps++, pe++)
1510         {
1511                 VectorLerp(ps->v, startfrac, pe->v, tempstart);
1512                 VectorLerp(ps->v, endfrac, pe->v, tempend);
1513                 mins[0] = min(mins[0], min(tempstart[0], tempend[0]));
1514                 mins[1] = min(mins[1], min(tempstart[1], tempend[1]));
1515                 mins[2] = min(mins[2], min(tempstart[2], tempend[2]));
1516                 maxs[0] = min(maxs[0], min(tempstart[0], tempend[0]));
1517                 maxs[1] = min(maxs[1], min(tempstart[1], tempend[1]));
1518                 maxs[2] = min(maxs[2], min(tempstart[2], tempend[2]));
1519         }
1520         mins[0] -= 1;
1521         mins[1] -= 1;
1522         mins[2] -= 1;
1523         maxs[0] += 1;
1524         maxs[1] += 1;
1525         maxs[2] += 1;
1526 }
1527