collision.c

   1
   2 #include "quakedef.h"
   3 #include "polygon.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)
 406 {
 407         int j, k, m, w;
 408         int numpoints = 0, maxpoints = 256, numplanes = 0, maxplanes = 256, numelements = 0, maxelements = 256, numtriangles = 0;
 409         colbrushf_t *brush;
 410         colpointf_t pointsbuf[256];
 411         colplanef_t planesbuf[256];
 412         int elementsbuf[1024];
 413         int polypointbuf[256];
 414         int pmaxpoints = 64;
 415         int pnumpoints;
 416         float p[2][3*64];
 417         // construct a collision brush (points, planes, and renderable mesh) from
 418         // a set of planes, this also optimizes out any unnecessary planes (ones
 419         // whose polygon is clipped away by the other planes)
 420         for (j = 0;j < numoriginalplanes;j++)
 421         {
 422                 // add the plane uniquely (no duplicates)
 423                 for (k = 0;k < numplanes;k++)
 424                         if (VectorCompare(planesbuf[k].normal, originalplanes[j].normal) && planesbuf[k].dist == originalplanes[j].dist)
 425                                 break;
 426                 // if the plane is a duplicate, skip it
 427                 if (k < numplanes)
 428                         continue;
 429                 // check if there are too many and skip the brush
 430                 if (numplanes >= maxplanes)
 431                 {
 432                         Con_Print("Mod_Q3BSP_LoadBrushes: failed to build collision brush: too many planes for buffer\n");
 433                         return NULL;
 434                 }
 435
 436                 // create a large polygon from the plane
 437                 w = 0;
 438                 PolygonF_QuadForPlane(p[w], originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist, 1024.0*1024.0*1024.0);
 439                 pnumpoints = 4;
 440                 // clip it by all other planes
 441                 for (k = 0;k < numoriginalplanes && pnumpoints && pnumpoints <= pmaxpoints;k++)
 442                 {
 443                         if (k != j)
 444                         {
 445                                 // we want to keep the inside of the brush plane so we flip
 446                                 // the cutting plane
 447                                 PolygonF_Divide(pnumpoints, p[w], -originalplanes[k].normal[0], -originalplanes[k].normal[1], -originalplanes[k].normal[2], -originalplanes[k].dist, 1.0/32.0, maxpoints, p[!w], &pnumpoints, 0, NULL, NULL);
 448                                 w = !w;
 449                         }
 450                 }
 451                 // if nothing is left, skip it
 452                 if (!pnumpoints)
 453                         continue;
 454
 455                 // check if there are too many polygon vertices for buffer
 456                 if (pnumpoints > pmaxpoints)
 457                 {
 458                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 459                         return NULL;
 460                 }
 461
 462                 // check if there are too many triangle elements for buffer
 463                 if (numelements + (pnumpoints - 2) * 3 > maxelements)
 464                 {
 465                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
 466                         return NULL;
 467                 }
 468
 469                 for (k = 0;k < pnumpoints;k++)
 470                 {
 471                         // check if there is already a matching point (no duplicates)
 472                         for (m = 0;m < numpoints;m++)
 473                                 if (VectorDistance2(&p[w][k*3], pointsbuf[m].v) < COLLISION_SNAP)
 474                                         break;
 475
 476                         // if there is no match, add a new one
 477                         if (m == numpoints)
 478                         {
 479                                 // check if there are too many and skip the brush
 480                                 if (numpoints >= maxpoints)
 481                                 {
 482                                         Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 483                                         return NULL;
 484                                 }
 485                                 // add the new one
 486                                 VectorCopy(&p[w][k*3], pointsbuf[numpoints].v);
 487                                 numpoints++;
 488                         }
 489
 490                         // store the index into a buffer
 491                         polypointbuf[k] = m;
 492                 }
 493
 494                 // add the triangles for the polygon
 495                 // (this particular code makes a triangle fan)
 496                 for (k = 0;k < pnumpoints - 2;k++)
 497                 {
 498                         numtriangles++;
 499                         elementsbuf[numelements++] = polypointbuf[0];
 500                         elementsbuf[numelements++] = polypointbuf[k + 1];
 501                         elementsbuf[numelements++] = polypointbuf[k + 2];
 502                 }
 503
 504                 // add the new plane
 505                 VectorCopy(originalplanes[j].normal, planesbuf[numplanes].normal);
 506                 planesbuf[numplanes].dist = originalplanes[j].dist;
 507                 numplanes++;
 508         }
 509
 510         // if nothing is left, there's nothing to allocate
 511         if (numtriangles < 4 || numplanes < 4 || numpoints < 4)
 512                 return NULL;
 513
 514         // allocate the brush and copy to it
 515         brush = Collision_AllocBrushFloat(mempool, numpoints, numplanes, numtriangles, supercontents);
 516         memcpy(brush->points, pointsbuf, numpoints * sizeof(colpointf_t));
 517         memcpy(brush->planes, planesbuf, numplanes * sizeof(colplanef_t));
 518         memcpy(brush->elements, elementsbuf, numtriangles * sizeof(int[3]));
 519         // recalc distances
 520         for (j = 0;j < brush->numplanes;j++)
 521                 brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
 522         VectorCopy(brush->points[0].v, brush->mins);
 523         VectorCopy(brush->points[0].v, brush->maxs);
 524         for (j = 1;j < brush->numpoints;j++)
 525         {
 526                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
 527                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
 528                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
 529                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
 530                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
 531                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
 532         }
 533         brush->mins[0] -= 1;
 534         brush->mins[1] -= 1;
 535         brush->mins[2] -= 1;
 536         brush->maxs[0] += 1;
 537         brush->maxs[1] += 1;
 538         brush->maxs[2] += 1;
 539         Collision_ValidateBrush(brush);
 540         return brush;
 541 }
 542
 543
 544
 545 colbrushf_t *Collision_AllocBrushFloat(mempool_t *mempool, int numpoints, int numplanes, int numtriangles, int supercontents)
 546 {
 547         colbrushf_t *brush;
 548         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpoints + sizeof(colplanef_t) * numplanes + sizeof(int[3]) * numtriangles);
 549         brush->supercontents = supercontents;
 550         brush->numplanes = numplanes;
 551         brush->numpoints = numpoints;
 552         brush->numtriangles = numtriangles;
 553         brush->planes = (void *)(brush + 1);
 554         brush->points = (void *)(brush->planes + brush->numplanes);
 555         brush->elements = (void *)(brush->points + brush->numpoints);
 556         return brush;
 557 }
 558
 559 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 560 {
 561         int i;
 562         float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist;
 563         colpointf_t *p, *p2;
 564
 565         if (brush->numpoints == 3)
 566         {
 567                 // optimized triangle case
 568                 TriangleNormal(brush->points[0].v, brush->points[1].v, brush->points[2].v, brush->planes[0].normal);
 569                 if (DotProduct(brush->planes[0].normal, brush->planes[0].normal) < 0.0001f)
 570                 {
 571                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 572                         brush->numplanes = 0;
 573                         return;
 574                 }
 575                 else
 576                 {
 577                         brush->numplanes = 5;
 578                         VectorNormalize(brush->planes[0].normal);
 579                         brush->planes[0].dist = DotProduct(brush->points->v, brush->planes[0].normal);
 580                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 581                         brush->planes[1].dist = -brush->planes[0].dist;
 582                         VectorSubtract(brush->points[2].v, brush->points[0].v, edge0);
 583                         VectorSubtract(brush->points[0].v, brush->points[1].v, edge1);
 584                         VectorSubtract(brush->points[1].v, brush->points[2].v, edge2);
 585 #if 1
 586                         {
 587                                 float projectionnormal[3], projectionedge0[3], projectionedge1[3], projectionedge2[3];
 588                                 int i, best;
 589                                 float dist, bestdist;
 590                                 bestdist = fabs(brush->planes[0].normal[0]);
 591                                 best = 0;
 592                                 for (i = 1;i < 3;i++)
 593                                 {
 594                                         dist = fabs(brush->planes[0].normal[i]);
 595                                         if (bestdist < dist)
 596                                         {
 597                                                 bestdist = dist;
 598                                                 best = i;
 599                                         }
 600                                 }
 601                                 VectorClear(projectionnormal);
 602                                 if (brush->planes[0].normal[best] < 0)
 603                                         projectionnormal[best] = -1;
 604                                 else
 605                                         projectionnormal[best] = 1;
 606                                 VectorCopy(edge0, projectionedge0);
 607                                 VectorCopy(edge1, projectionedge1);
 608                                 VectorCopy(edge2, projectionedge2);
 609                                 projectionedge0[best] = 0;
 610                                 projectionedge1[best] = 0;
 611                                 projectionedge2[best] = 0;
 612                                 CrossProduct(projectionedge0, projectionnormal, brush->planes[2].normal);
 613                                 CrossProduct(projectionedge1, projectionnormal, brush->planes[3].normal);
 614                                 CrossProduct(projectionedge2, projectionnormal, brush->planes[4].normal);
 615                         }
 616 #else
 617                         CrossProduct(edge0, brush->planes->normal, brush->planes[2].normal);
 618                         CrossProduct(edge1, brush->planes->normal, brush->planes[3].normal);
 619                         CrossProduct(edge2, brush->planes->normal, brush->planes[4].normal);
 620 #endif
 621                         VectorNormalize(brush->planes[2].normal);
 622                         VectorNormalize(brush->planes[3].normal);
 623                         VectorNormalize(brush->planes[4].normal);
 624                         brush->planes[2].dist = DotProduct(brush->points[2].v, brush->planes[2].normal);
 625                         brush->planes[3].dist = DotProduct(brush->points[0].v, brush->planes[3].normal);
 626                         brush->planes[4].dist = DotProduct(brush->points[1].v, brush->planes[4].normal);
 627
 628                         if (developer.integer)
 629                         {
 630                                 // validation code
 631 #if 0
 632                                 float temp[3];
 633
 634                                 VectorSubtract(brush->points[0].v, brush->points[1].v, edge0);
 635                                 VectorSubtract(brush->points[2].v, brush->points[1].v, edge1);
 636                                 CrossProduct(edge0, edge1, normal);
 637                                 VectorNormalize(normal);
 638                                 VectorSubtract(normal, brush->planes[0].normal, temp);
 639                                 if (VectorLength(temp) > 0.01f)
 640                                         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]);
 641                                 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)
 642                                         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);
 643 #if 0
 644                                 if (fabs(DotProduct(brush->planes[2].normal, brush->planes[0].normal)) > 0.01f)
 645                                         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);
 646                                 if (fabs(DotProduct(brush->planes[3].normal, brush->planes[0].normal)) > 0.01f)
 647                                         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);
 648                                 if (fabs(DotProduct(brush->planes[4].normal, brush->planes[0].normal)) > 0.01f)
 649                                         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);
 650                                 if (fabs(DotProduct(brush->planes[2].normal, edge0)) > 0.01f)
 651                                         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]);
 652                                 if (fabs(DotProduct(brush->planes[3].normal, edge1)) > 0.01f)
 653                                         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]);
 654                                 if (fabs(DotProduct(brush->planes[4].normal, edge2)) > 0.01f)
 655                                         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]);
 656 #endif
 657 #endif
 658                                 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)
 659                                         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);
 660                                 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)
 661                                         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);
 662                                 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)
 663                                         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);
 664                                 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)
 665                                         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);
 666                                 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)
 667                                         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);
 668                         }
 669                 }
 670         }
 671         else
 672         {
 673                 // choose best surface normal for polygon's plane
 674                 bestdist = 0;
 675                 for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
 676                 {
 677                         VectorSubtract(p[-1].v, p[0].v, edge0);
 678                         VectorSubtract(p[1].v, p[0].v, edge1);
 679                         CrossProduct(edge0, edge1, normal);
 680                         //TriangleNormal(p[-1].v, p[0].v, p[1].v, normal);
 681                         dist = DotProduct(normal, normal);
 682                         if (i == 0 || bestdist < dist)
 683                         {
 684                                 bestdist = dist;
 685                                 VectorCopy(normal, brush->planes->normal);
 686                         }
 687                 }
 688                 if (bestdist < 0.0001f)
 689                 {
 690                         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
 691                         brush->numplanes = 0;
 692                         return;
 693                 }
 694                 else
 695                 {
 696                         brush->numplanes = brush->numpoints + 2;
 697                         VectorNormalize(brush->planes->normal);
 698                         brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
 699
 700                         // negate plane to create other side
 701                         VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
 702                         brush->planes[1].dist = -brush->planes[0].dist;
 703                         for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
 704                         {
 705                                 VectorSubtract(p->v, p2->v, edge0);
 706                                 CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
 707                                 VectorNormalize(brush->planes[i + 2].normal);
 708                                 brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
 709                         }
 710                 }
 711         }
 712
 713         if (developer.integer)
 714         {
 715                 // validity check - will be disabled later
 716                 Collision_ValidateBrush(brush);
 717                 for (i = 0;i < brush->numplanes;i++)
 718                 {
 719                         int j;
 720                         for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
 721                                 if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + (1.0 / 32.0))
 722                                         Con_Printf("Error in brush plane generation, plane %i\n", i);
 723                 }
 724         }
 725 }
 726
 727 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents)
 728 {
 729         colbrushf_t *brush;
 730         brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
 731         brush->supercontents = supercontents;
 732         brush->numpoints = numpoints;
 733         brush->numplanes = numpoints + 2;
 734         brush->planes = (void *)(brush + 1);
 735         brush->points = (colpointf_t *)points;
 736         Host_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...\n");
 737         return brush;
 738 }
 739
 740 // NOTE: start and end of each brush pair must have same numplanes/numpoints
 741 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)
 742 {
 743         int nplane, nplane2, fstartsolid, fendsolid, brushsolid;
 744         float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
 745         const colplanef_t *startplane, *endplane;
 746
 747         enterfrac = -1;
 748         enterfrac2 = -1;
 749         leavefrac = 1;
 750         fstartsolid = true;
 751         fendsolid = true;
 752
 753         for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
 754         {
 755                 nplane2 = nplane;
 756                 if (nplane2 >= thatbrush_start->numplanes)
 757                 {
 758                         nplane2 -= thatbrush_start->numplanes;
 759                         startplane = thisbrush_start->planes + nplane2;
 760                         endplane = thisbrush_end->planes + nplane2;
 761                         if (developer.integer)
 762                         {
 763                                 // any brush with degenerate planes is not worth handling
 764                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 765                                 {
 766                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thisbrush plane!\n");
 767                                         return;
 768                                 }
 769                                 f = furthestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints);
 770                                 if (fabs(f - startplane->dist) > 0.01f)
 771                                         Con_Printf("startplane->dist %f != calculated %f (thisbrush_start)\n", startplane->dist, f);
 772                         }
 773                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints) - collision_startnudge.value;
 774                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - collision_endnudge.value;
 775                 }
 776                 else
 777                 {
 778                         startplane = thatbrush_start->planes + nplane2;
 779                         endplane = thatbrush_end->planes + nplane2;
 780                         if (developer.integer)
 781                         {
 782                                 // any brush with degenerate planes is not worth handling
 783                                 if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 784                                 {
 785                                         Con_Print("Collision_TraceBrushBrushFloat: degenerate thatbrush plane!\n");
 786                                         return;
 787                                 }
 788                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 789                                 if (fabs(f - startplane->dist) > 0.01f)
 790                                         Con_Printf("startplane->dist %f != calculated %f (thatbrush_start)\n", startplane->dist, f);
 791                         }
 792                         d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - startplane->dist - collision_startnudge.value;
 793                         d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - endplane->dist - collision_endnudge.value;
 794                 }
 795                 //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 796
 797                 move = d1 - d2;
 798                 if (move > 0)
 799                 {
 800                         // moving into brush
 801                         if (d2 > collision_enternudge.value)
 802                                 return;
 803                         if (d1 < 0)
 804                                 continue;
 805                         // enter
 806                         fstartsolid = false;
 807                         imove = 1 / move;
 808                         f = (d1 - collision_enternudge.value) * imove;
 809                         f = bound(0, f, 1);
 810                         if (enterfrac < f)
 811                         {
 812                                 enterfrac = f;
 813                                 enterfrac2 = f - collision_impactnudge.value * imove;
 814                                 enterfrac2 = bound(0, enterfrac2, 1);
 815                                 VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 816                         }
 817                 }
 818                 else if (move < 0)
 819                 {
 820                         // moving out of brush
 821                         if (d1 > collision_leavenudge.value)
 822                                 return;
 823                         if (d2 < 0)
 824                                 continue;
 825                         // leave
 826                         fendsolid = false;
 827                         f = (d1 + collision_leavenudge.value) / move;
 828                         f = bound(0, f, 1);
 829                         if (leavefrac > f)
 830                                 leavefrac = f;
 831                 }
 832                 else
 833                 {
 834                         // sliding along plane
 835                         if (d1 > 0)
 836                                 return;
 837                 }
 838         }
 839
 840         brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
 841         if (fstartsolid)
 842         {
 843                 trace->startsupercontents |= thatbrush_start->supercontents;
 844                 if (brushsolid)
 845                 {
 846                         trace->startsolid = true;
 847                         if (fendsolid)
 848                                 trace->allsolid = true;
 849                 }
 850         }
 851
 852         // LordHavoc: we need an epsilon nudge here because for a point trace the
 853         // penetrating line segment is normally zero length if this brush was
 854         // generated from a polygon (infinitely thin), and could even be slightly
 855         // positive or negative due to rounding errors in that case.
 856         if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
 857         {
 858 #if 0
 859                 // broken
 860                 if (thatbrush_start->ispolygon)
 861                 {
 862                         d1 = nearestplanedist_float(thatbrush_start->planes[0].normal, thisbrush_start->points, thisbrush_start->numpoints) - thatbrush_start->planes[0].dist - collision_startnudge.value;
 863                         d2 = nearestplanedist_float(thatbrush_end->planes[0].normal, thisbrush_end->points, thisbrush_end->numpoints) - thatbrush_end->planes[0].dist - collision_endnudge.value;
 864                         move = d1 - d2;
 865                         if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
 866                                 return;
 867                         // enter
 868                         imove = 1 / move;
 869                         enterfrac = (d1 - collision_enternudge.value) * imove;
 870                         if (enterfrac < trace->realfraction)
 871                         {
 872                                 enterfrac2 = enterfrac - collision_impactnudge.value * imove;
 873                                 trace->realfraction = bound(0, enterfrac, 1);
 874                                 trace->fraction = bound(0, enterfrac2, 1);
 875                                 VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
 876                         }
 877                 }
 878                 else
 879 #endif
 880                 {
 881                         trace->realfraction = bound(0, enterfrac, 1);
 882                         trace->fraction = bound(0, enterfrac2, 1);
 883                         VectorCopy(newimpactnormal, trace->plane.normal);
 884                 }
 885         }
 886 }
 887
 888 // NOTE: start and end brush pair must have same numplanes/numpoints
 889 void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
 890 {
 891         int nplane, fstartsolid, fendsolid, brushsolid;
 892         float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
 893         const colplanef_t *startplane, *endplane;
 894
 895         enterfrac = -1;
 896         enterfrac2 = -1;
 897         leavefrac = 1;
 898         fstartsolid = true;
 899         fendsolid = true;
 900
 901         for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
 902         {
 903                 startplane = thatbrush_start->planes + nplane;
 904                 endplane = thatbrush_end->planes + nplane;
 905                 d1 = DotProduct(startplane->normal, linestart) - startplane->dist - collision_startnudge.value;
 906                 d2 = DotProduct(endplane->normal, lineend) - endplane->dist - collision_endnudge.value;
 907                 if (developer.integer)
 908                 {
 909                         // any brush with degenerate planes is not worth handling
 910                         if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
 911                         {
 912                                 Con_Print("Collision_TraceLineBrushFloat: degenerate plane!\n");
 913                                 return;
 914                         }
 915                         if (thatbrush_start->numpoints)
 916                         {
 917                                 f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
 918                                 if (fabs(f - startplane->dist) > 0.01f)
 919                                         Con_Printf("startplane->dist %f != calculated %f\n", startplane->dist, f);
 920                         }
 921                 }
 922
 923                 move = d1 - d2;
 924                 if (move > 0)
 925                 {
 926                         // moving into brush
 927                         if (d2 >= 0)
 928                                 return;
 929                         if (d1 <= 0)
 930                                 continue;
 931                         // enter
 932                         fstartsolid = false;
 933                         imove = 1 / move;
 934                         f = (d1 - collision_enternudge.value) * imove;
 935                         if (enterfrac < f)
 936                         {
 937                                 enterfrac = f;
 938                                 enterfrac2 = f - collision_impactnudge.value * imove;
 939                                 VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
 940                         }
 941                 }
 942                 else
 943                 {
 944                         // moving out of brush
 945                         if (d1 >= 0)
 946                                 return;
 947                         if (d2 <= 0)
 948                                 continue;
 949                         // leave
 950                         fendsolid = false;
 951                         f = (d1 - collision_leavenudge.value) / move;
 952                         if (leavefrac > f)
 953                                 leavefrac = f;
 954                 }
 955         }
 956
 957         brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
 958         if (fstartsolid)
 959         {
 960                 trace->startsupercontents |= thatbrush_start->supercontents;
 961                 if (brushsolid)
 962                 {
 963                         trace->startsolid = true;
 964                         if (fendsolid)
 965                                 trace->allsolid = true;
 966                 }
 967         }
 968
 969         // LordHavoc: we need an epsilon nudge here because for a point trace the
 970         // penetrating line segment is normally zero length if this brush was
 971         // generated from a polygon (infinitely thin), and could even be slightly
 972         // positive or negative due to rounding errors in that case.
 973         if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
 974         {
 975 #if 0
 976                 // broken
 977                 if (thatbrush_start->ispolygon)
 978                 {
 979                         d1 = DotProduct(thatbrush_start->planes[0].normal, linestart) - thatbrush_start->planes[0].dist - collision_startnudge.value;
 980                         d2 = DotProduct(thatbrush_end->planes[0].normal, lineend) - thatbrush_end->planes[0].dist - collision_endnudge.value;
 981                         move = d1 - d2;
 982                         if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
 983                                 return;
 984                         // enter
 985                         imove = 1 / move;
 986                         enterfrac = (d1 - collision_enternudge.value) * imove;
 987                         if (enterfrac < trace->realfraction)
 988                         {
 989                                 enterfrac2 = enterfrac - collision_impactnudge.value * imove;
 990                                 trace->realfraction = bound(0, enterfrac, 1);
 991                                 trace->fraction = bound(0, enterfrac2, 1);
 992                                 VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
 993                         }
 994                 }
 995                 else
 996 #endif
 997                 {
 998                         trace->realfraction = bound(0, enterfrac, 1);
 999                         trace->fraction = bound(0, enterfrac2, 1);
1000                         VectorCopy(newimpactnormal, trace->plane.normal);
1001                 }
1002         }
1003 }
1004
1005 void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
1006 {
1007         int nplane;
1008         const colplanef_t *plane;
1009
1010         for (nplane = 0, plane = thatbrush->planes;nplane < thatbrush->numplanes;nplane++, plane++)
1011                 if (DotProduct(plane->normal, point) > plane->dist)
1012                         return;
1013
1014         trace->startsupercontents |= thatbrush->supercontents;
1015         if (trace->hitsupercontentsmask & thatbrush->supercontents)
1016         {
1017                 trace->startsolid = true;
1018                 trace->allsolid = true;
1019         }
1020 }
1021
1022 static colpointf_t polyf_points[256];
1023 static colplanef_t polyf_planes[256 + 2];
1024 static colbrushf_t polyf_brush;
1025
1026 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
1027 {
1028         while (numpoints--)
1029         {
1030                 out->v[0] = floor(in->v[0] * fractionprecision + 0.5f) * invfractionprecision;
1031                 out->v[1] = floor(in->v[1] * fractionprecision + 0.5f) * invfractionprecision;
1032                 out->v[2] = floor(in->v[2] * fractionprecision + 0.5f) * invfractionprecision;
1033         }
1034 }
1035
1036 void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, int supercontents)
1037 {
1038         if (numpoints > 256)
1039         {
1040                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1041                 return;
1042         }
1043         polyf_brush.numpoints = numpoints;
1044         polyf_brush.numplanes = numpoints + 2;
1045         //polyf_brush.points = (colpointf_t *)points;
1046         polyf_brush.planes = polyf_planes;
1047         polyf_brush.supercontents = supercontents;
1048         polyf_brush.points = polyf_points;
1049         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1050         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1051         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1052         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
1053 }
1054
1055 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)
1056 {
1057         int i;
1058         float facemins[3], facemaxs[3];
1059         polyf_brush.numpoints = 3;
1060         polyf_brush.numplanes = 5;
1061         polyf_brush.points = polyf_points;
1062         polyf_brush.planes = polyf_planes;
1063         polyf_brush.supercontents = supercontents;
1064         for (i = 0;i < numtriangles;i++, element3i += 3)
1065         {
1066                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
1067                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
1068                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
1069                 Collision_SnapCopyPoints(3, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1070                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0])) - 1;
1071                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
1072                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
1073                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
1074                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
1075                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
1076                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
1077                 {
1078                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1079                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1080                         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
1081                 }
1082         }
1083 }
1084
1085 void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numpoints, const float *points, int supercontents)
1086 {
1087         if (numpoints > 256)
1088         {
1089                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1090                 return;
1091         }
1092         polyf_brush.numpoints = numpoints;
1093         polyf_brush.numplanes = numpoints + 2;
1094         //polyf_brush.points = (colpointf_t *)points;
1095         polyf_brush.points = polyf_points;
1096         Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1097         polyf_brush.planes = polyf_planes;
1098         polyf_brush.supercontents = supercontents;
1099         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1100         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1101         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
1102 }
1103
1104 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)
1105 {
1106         int i;
1107 #if 1
1108         // FIXME: snap vertices?
1109         for (i = 0;i < numtriangles;i++, element3i += 3)
1110                 Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3);
1111 #else
1112         polyf_brush.numpoints = 3;
1113         polyf_brush.numplanes = 5;
1114         polyf_brush.points = polyf_points;
1115         polyf_brush.planes = polyf_planes;
1116         polyf_brush.supercontents = supercontents;
1117         for (i = 0;i < numtriangles;i++, element3i += 3)
1118         {
1119                 float facemins[3], facemaxs[3];
1120                 VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
1121                 VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
1122                 VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
1123                 Collision_SnapCopyPoints(numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
1124                 facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0])) - 1;
1125                 facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
1126                 facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
1127                 facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
1128                 facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
1129                 facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
1130                 if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
1131                 {
1132                         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
1133                         //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
1134                         Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
1135                 }
1136         }
1137 #endif
1138 }
1139
1140
1141 static colpointf_t polyf_pointsstart[256], polyf_pointsend[256];
1142 static colplanef_t polyf_planesstart[256 + 2], polyf_planesend[256 + 2];
1143 static colbrushf_t polyf_brushstart, polyf_brushend;
1144
1145 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)
1146 {
1147         int i;
1148         if (numpoints > 256)
1149         {
1150                 Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
1151                 return;
1152         }
1153         polyf_brushstart.numpoints = numpoints;
1154         polyf_brushstart.numplanes = numpoints + 2;
1155         polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
1156         polyf_brushstart.planes = polyf_planesstart;
1157         polyf_brushstart.supercontents = supercontents;
1158         for (i = 0;i < numpoints;i++)
1159                 Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
1160         polyf_brushend.numpoints = numpoints;
1161         polyf_brushend.numplanes = numpoints + 2;
1162         polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
1163         polyf_brushend.planes = polyf_planesend;
1164         polyf_brushend.supercontents = supercontents;
1165         for (i = 0;i < numpoints;i++)
1166                 Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
1167         Collision_SnapCopyPoints(numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
1168         Collision_SnapCopyPoints(numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
1169         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
1170         Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
1171
1172         //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
1173         //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
1174
1175         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend);
1176 }
1177
1178
1179
1180 #define MAX_BRUSHFORBOX 16
1181 static int brushforbox_index = 0;
1182 static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
1183 static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
1184 static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
1185 static colbrushf_t brushforpoint_brush[MAX_BRUSHFORBOX];
1186
1187 void Collision_InitBrushForBox(void)
1188 {
1189         int i;
1190         for (i = 0;i < MAX_BRUSHFORBOX;i++)
1191         {
1192                 brushforbox_brush[i].supercontents = SUPERCONTENTS_SOLID;
1193                 brushforbox_brush[i].numpoints = 8;
1194                 brushforbox_brush[i].numplanes = 6;
1195                 brushforbox_brush[i].points = brushforbox_point + i * 8;
1196                 brushforbox_brush[i].planes = brushforbox_plane + i * 6;
1197                 brushforpoint_brush[i].supercontents = SUPERCONTENTS_SOLID;
1198                 brushforpoint_brush[i].numpoints = 1;
1199                 brushforpoint_brush[i].numplanes = 0;
1200                 brushforpoint_brush[i].points = brushforbox_point + i * 8;
1201                 brushforpoint_brush[i].planes = brushforbox_plane + i * 6;
1202         }
1203 }
1204
1205 colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs)
1206 {
1207         int i, j;
1208         vec3_t v;
1209         colbrushf_t *brush;
1210         if (brushforbox_brush[0].numpoints == 0)
1211                 Collision_InitBrushForBox();
1212         if (VectorCompare(mins, maxs))
1213         {
1214                 // point brush
1215                 brush = brushforpoint_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1216                 VectorCopy(mins, brush->points->v);
1217         }
1218         else
1219         {
1220                 brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
1221                 // FIXME: optimize
1222                 for (i = 0;i < 8;i++)
1223                 {
1224                         v[0] = i & 1 ? maxs[0] : mins[0];
1225                         v[1] = i & 2 ? maxs[1] : mins[1];
1226                         v[2] = i & 4 ? maxs[2] : mins[2];
1227                         Matrix4x4_Transform(matrix, v, brush->points[i].v);
1228                 }
1229                 // FIXME: optimize!
1230                 for (i = 0;i < 6;i++)
1231                 {
1232                         VectorClear(v);
1233                         v[i >> 1] = i & 1 ? 1 : -1;
1234                         Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
1235                         VectorNormalize(brush->planes[i].normal);
1236                 }
1237         }
1238         for (j = 0;j < brush->numplanes;j++)
1239                 brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
1240         VectorCopy(brush->points[0].v, brush->mins);
1241         VectorCopy(brush->points[0].v, brush->maxs);
1242         for (j = 1;j < brush->numpoints;j++)
1243         {
1244                 brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
1245                 brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
1246                 brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
1247                 brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
1248                 brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
1249                 brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
1250         }
1251         brush->mins[0] -= 1;
1252         brush->mins[1] -= 1;
1253         brush->mins[2] -= 1;
1254         brush->maxs[0] += 1;
1255         brush->maxs[1] += 1;
1256         brush->maxs[2] += 1;
1257         Collision_ValidateBrush(brush);
1258         return brush;
1259 }
1260
1261 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)
1262 {
1263         colbrushf_t *boxbrush, *thisbrush_start, *thisbrush_end;
1264         matrix4x4_t identitymatrix;
1265         vec3_t startmins, startmaxs, endmins, endmaxs;
1266
1267         // create brushes for the collision
1268         VectorAdd(start, mins, startmins);
1269         VectorAdd(start, maxs, startmaxs);
1270         VectorAdd(end, mins, endmins);
1271         VectorAdd(end, maxs, endmaxs);
1272         Matrix4x4_CreateIdentity(&identitymatrix);
1273         boxbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs);
1274         thisbrush_start = Collision_BrushForBox(&identitymatrix, startmins, startmaxs);
1275         thisbrush_end = Collision_BrushForBox(&identitymatrix, endmins, endmaxs);
1276
1277         memset(trace, 0, sizeof(trace_t));
1278         trace->hitsupercontentsmask = hitsupercontentsmask;
1279         trace->fraction = 1;
1280         trace->realfraction = 1;
1281         trace->allsolid = true;
1282         Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, boxbrush, boxbrush);
1283 }
1284
1285 // LordHavoc: currently unused and not yet tested
1286 // note: this can be used for tracing a moving sphere vs a stationary sphere,
1287 // by simply adding the moving sphere's radius to the sphereradius parameter,
1288 // all the results are correct (impactpoint, impactnormal, and fraction)
1289 float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
1290 {
1291         double dir[3], scale, v[3], deviationdist, impactdist, linelength;
1292         // make sure the impactpoint and impactnormal are valid even if there is
1293         // no collision
1294         impactpoint[0] = lineend[0];
1295         impactpoint[1] = lineend[1];
1296         impactpoint[2] = lineend[2];
1297         impactnormal[0] = 0;
1298         impactnormal[1] = 0;
1299         impactnormal[2] = 0;
1300         // calculate line direction
1301         dir[0] = lineend[0] - linestart[0];
1302         dir[1] = lineend[1] - linestart[1];
1303         dir[2] = lineend[2] - linestart[2];
1304         // normalize direction
1305         linelength = sqrt(dir[0] * dir[0] + dir[1] * dir[1] + dir[2] * dir[2]);
1306         if (linelength)
1307         {
1308                 scale = 1.0 / linelength;
1309                 dir[0] *= scale;
1310                 dir[1] *= scale;
1311                 dir[2] *= scale;
1312         }
1313         // this dotproduct calculates the distance along the line at which the
1314         // sphere origin is (nearest point to the sphere origin on the line)
1315         impactdist = dir[0] * (sphereorigin[0] - linestart[0]) + dir[1] * (sphereorigin[1] - linestart[1]) + dir[2] * (sphereorigin[2] - linestart[2]);
1316         // calculate point on line at that distance, and subtract the
1317         // sphereorigin from it, so we have a vector to measure for the distance
1318         // of the line from the sphereorigin (deviation, how off-center it is)
1319         v[0] = linestart[0] + impactdist * dir[0] - sphereorigin[0];
1320         v[1] = linestart[1] + impactdist * dir[1] - sphereorigin[1];
1321         v[2] = linestart[2] + impactdist * dir[2] - sphereorigin[2];
1322         deviationdist = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
1323         // if outside the radius, it's a miss for sure
1324         // (we do this comparison using squared radius to avoid a sqrt)
1325         if (deviationdist > sphereradius*sphereradius)
1326                 return 1; // miss (off to the side)
1327         // nudge back to find the correct impact distance
1328         impactdist += (sqrt(deviationdist) - sphereradius);
1329         if (impactdist >= linelength)
1330                 return 1; // miss (not close enough)
1331         if (impactdist < 0)
1332                 return 1; // miss (linestart is past or inside sphere)
1333         // calculate new impactpoint
1334         impactpoint[0] = linestart[0] + impactdist * dir[0];
1335         impactpoint[1] = linestart[1] + impactdist * dir[1];
1336         impactpoint[2] = linestart[2] + impactdist * dir[2];
1337         // calculate impactnormal (surface normal at point of impact)
1338         impactnormal[0] = impactpoint[0] - sphereorigin[0];
1339         impactnormal[1] = impactpoint[1] - sphereorigin[1];
1340         impactnormal[2] = impactpoint[2] - sphereorigin[2];
1341         // normalize impactnormal
1342         scale = impactnormal[0] * impactnormal[0] + impactnormal[1] * impactnormal[1] + impactnormal[2] * impactnormal[2];
1343         if (scale)
1344         {
1345                 scale = 1.0 / sqrt(scale);
1346                 impactnormal[0] *= scale;
1347                 impactnormal[1] *= scale;
1348                 impactnormal[2] *= scale;
1349         }
1350         // return fraction of movement distance
1351         return impactdist / linelength;
1352 }
1353
1354 void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2)
1355 {
1356         float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
1357
1358         // this code is designed for clockwise triangles, conversion to
1359         // counterclockwise would require swapping some things around...
1360         // it is easier to simply swap the point0 and point2 parameters to this
1361         // function when calling it than it is to rewire the internals.
1362
1363         // calculate the faceplanenormal of the triangle, this represents the front side
1364         TriangleNormal(point0, point1, point2, faceplanenormal);
1365         // there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
1366         if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
1367                 return;
1368         // normalize the normal
1369         VectorNormalize(faceplanenormal);
1370         // calculate the distance
1371         faceplanedist = DotProduct(point0, faceplanenormal);
1372
1373         // calculate the start distance
1374         d1 = DotProduct(faceplanenormal, linestart) - faceplanedist;
1375         // if start point is on the back side there is no collision
1376         // (we don't care about traces going through the triangle the wrong way)
1377         if (d1 < 0)
1378                 return;
1379
1380         // calculate the end distance
1381         d2 = DotProduct(faceplanenormal, lineend) - faceplanedist;
1382         // if both are in front, there is no collision
1383         if (d2 >= 0)
1384                 return;
1385
1386         // from here on we know d1 is >= 0 and d2 is < 0
1387         // this means the line starts infront and ends behind, passing through it
1388
1389         // calculate the recipricol of the distance delta,
1390         // so we can use it multiple times cheaply (instead of division)
1391         d = 1.0f / (d1 - d2);
1392         // calculate the impact fraction by taking the start distance (> 0)
1393         // and subtracting the face plane distance (this is the distance of the
1394         // triangle along that same normal)
1395         // then multiply by the recipricol distance delta
1396         f = d1 * d;
1397         // skip out if this impact is further away than previous ones
1398         if (f > trace->realfraction)
1399                 return;
1400         // calculate the perfect impact point for classification of insidedness
1401         impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
1402         impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
1403         impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
1404
1405         // calculate the edge normal and reject if impact is outside triangle
1406         // (an edge normal faces away from the triangle, to get the desired normal
1407         //  a crossproduct with the faceplanenormal is used, and because of the way
1408         // the insidedness comparison is written it does not need to be normalized)
1409
1410         VectorSubtract(point2, point0, edge);
1411         CrossProduct(edge, faceplanenormal, edgenormal);
1412         if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
1413                 return;
1414
1415         VectorSubtract(point0, point1, edge);
1416         CrossProduct(edge, faceplanenormal, edgenormal);
1417         if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
1418                 return;
1419
1420         VectorSubtract(point1, point2, edge);
1421         CrossProduct(edge, faceplanenormal, edgenormal);
1422         if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
1423                 return;
1424
1425         // store the new trace fraction
1426         trace->realfraction = bound(0, f, 1);
1427
1428         // calculate a nudged fraction to keep it out of the surface
1429         // (the main fraction remains perfect)
1430         fnudged = (d1 - collision_impactnudge.value) * d;
1431         trace->fraction = bound(0, fnudged, 1);
1432
1433         // store the new trace endpos
1434         // not needed, it's calculated later when the trace is finished
1435         //trace->endpos[0] = linestart[0] + fnudged * (lineend[0] - linestart[0]);
1436         //trace->endpos[1] = linestart[1] + fnudged * (lineend[1] - linestart[1]);
1437         //trace->endpos[2] = linestart[2] + fnudged * (lineend[2] - linestart[2]);
1438
1439         // store the new trace plane (because collisions only happen from
1440         // the front this is always simply the triangle normal, never flipped)
1441         VectorCopy(faceplanenormal, trace->plane.normal);
1442         trace->plane.dist = faceplanedist;
1443 }
1444
1445 typedef struct colbspnode_s
1446 {
1447         mplane_t plane;
1448         struct colbspnode_s *children[2];
1449         // the node is reallocated or split if max is reached
1450         int numcolbrushf;
1451         int maxcolbrushf;
1452         colbrushf_t **colbrushflist;
1453         //int numcolbrushd;
1454         //int maxcolbrushd;
1455         //colbrushd_t **colbrushdlist;
1456 }
1457 colbspnode_t;
1458
1459 typedef struct colbsp_s
1460 {
1461         mempool_t *mempool;
1462         colbspnode_t *nodes;
1463 }
1464 colbsp_t;
1465
1466 colbsp_t *Collision_CreateCollisionBSP(mempool_t *mempool)
1467 {
1468         colbsp_t *bsp;
1469         bsp = Mem_Alloc(mempool, sizeof(colbsp_t));
1470         bsp->mempool = mempool;
1471         bsp->nodes = Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
1472         return bsp;
1473 }
1474
1475 void Collision_FreeCollisionBSPNode(colbspnode_t *node)
1476 {
1477         if (node->children[0])
1478                 Collision_FreeCollisionBSPNode(node->children[0]);
1479         if (node->children[1])
1480                 Collision_FreeCollisionBSPNode(node->children[1]);
1481         while (--node->numcolbrushf)
1482                 Mem_Free(node->colbrushflist[node->numcolbrushf]);
1483         //while (--node->numcolbrushd)
1484         //      Mem_Free(node->colbrushdlist[node->numcolbrushd]);
1485         Mem_Free(node);
1486 }
1487
1488 void Collision_FreeCollisionBSP(colbsp_t *bsp)
1489 {
1490         Collision_FreeCollisionBSPNode(bsp->nodes);
1491         Mem_Free(bsp);
1492 }
1493
1494 void Collision_BoundingBoxOfBrushTraceSegment(const colbrushf_t *start, const colbrushf_t *end, vec3_t mins, vec3_t maxs, float startfrac, float endfrac)
1495 {
1496         int i;
1497         colpointf_t *ps, *pe;
1498         float tempstart[3], tempend[3];
1499         VectorLerp(start->points[0].v, startfrac, end->points[0].v, mins);
1500         VectorCopy(mins, maxs);
1501         for (i = 0, ps = start->points, pe = end->points;i < start->numpoints;i++, ps++, pe++)
1502         {
1503                 VectorLerp(ps->v, startfrac, pe->v, tempstart);
1504                 VectorLerp(ps->v, endfrac, pe->v, tempend);
1505                 mins[0] = min(mins[0], min(tempstart[0], tempend[0]));
1506                 mins[1] = min(mins[1], min(tempstart[1], tempend[1]));
1507                 mins[2] = min(mins[2], min(tempstart[2], tempend[2]));
1508                 maxs[0] = min(maxs[0], min(tempstart[0], tempend[0]));
1509                 maxs[1] = min(maxs[1], min(tempstart[1], tempend[1]));
1510                 maxs[2] = min(maxs[2], min(tempstart[2], tempend[2]));
1511         }
1512         mins[0] -= 1;
1513         mins[1] -= 1;
1514         mins[2] -= 1;
1515         maxs[0] += 1;
1516         maxs[1] += 1;
1517         maxs[2] += 1;
1518 }
1519